文档库 最新最全的文档下载
当前位置:文档库 › Measurement of Residual Stresses Using Nanoindentation Method

Measurement of Residual Stresses Using Nanoindentation Method

Measurement of Residual Stresses Using Nanoindentation Method
Measurement of Residual Stresses Using Nanoindentation Method

Full Terms & Conditions of access and use can be found at

https://www.wendangku.net/doc/593718660.html,/action/journalInformation?journalCode=bsms20

Download by: [Aston University]

Date:

11 February 2016, At: 06:14

Critical Reviews in Solid State and Materials Sciences

ISSN: 1040-8436 (Print) 1547-6561 (Online) Journal homepage: https://www.wendangku.net/doc/593718660.html,/loi/bsms20

Measurement of Residual Stresses Using Nanoindentation Method

Li-Na Zhu, Bin-Shi Xu, Hai-Dou Wang & Cheng-Biao Wang

To cite this article: Li-Na Zhu, Bin-Shi Xu, Hai-Dou Wang & Cheng-Biao Wang (2015)

Measurement of Residual Stresses Using Nanoindentation Method, Critical Reviews in Solid State and Materials Sciences, 40:2, 77-89, DOI: 10.1080/10408436.2014.940442To link to this article:

https://www.wendangku.net/doc/593718660.html,/10.1080/10408436.2014.940442

Published online: 28 Oct 2014.

Submit your article to this journal

Article views: 306

View related articles

View Crossmark data

Measurement of Residual Stresses Using Nanoindentation Method

Li-Na Zhu,1Bin-Shi Xu,2Hai-Dou Wang,1,2,*and Cheng-Biao Wang 1

1School of Engineering and Technology,China University of Geosciences,Beijing 100083,China

2

National Key Lab for Remanufacturing,Academy of Armored Forces Engineering,Beijing 100072,China

Instrumented indentation,which is also known as nanoindentation or depth-sensing indentation,is increasingly being used to probe the residual stresses of materials including bulk solids,thin ?lms,and coatings.The residual stresses are proved to have signi?cant effects on various nanoindentation parameters such as hardness,loading curve,unloading curve,pile-up amount around indentation,and true contact area.By analyzing these parameters,numerous methods are developed to evaluate the residual stresses of materials in recent years.This article reviews six commonly used models which determine residual stresses from analyzing load-depth curves,as well as indentation fracture technique which is based on the classical fracture mechanics.Emphasis is placed on the principle,application and limitation of each nanoindentation method.Keywords

nanoindentation,residual stress,non-destructive testing

Table of Contents

1.INTRODUCTION ...........................................................................................................................................2

2.BASIC PRINCIPLES OF NANOINDENTATION METHOD .............................................................................2

3.

EFFECT OF RESIDUAL STRESSES ON NANOINDENTATION RESPONSE ...................................................43.1.Effect on Mechanical Properties..................................................................................................................43.2.Effect on Load-Depth Curves .....................................................................................................................43.3.Effect on Pile-Up......................................................................................................................................43.4.Effect on True Contact Area.......................................................................................................................54.

NANOINDENTATION MODELS FOR THE DETERMINATION OF RESIDUAL STRESS ...............................54.1.Suresh Model...........................................................................................................................................54.2.Lee Models. (7)

4.2.1.Lee Model I....................................................................................................................................74.2.2.Lee Model II...................................................................................................................................84.2.3.Application of Lee Models................................................................................................................84.3.Xu Model................................................................................................................................................84.4.Swadener Models . (9)

4.4.1.Swadener Model I...........................................................................................................................94.4.2.Swadener Model II..........................................................................................................................94.4.3.Limitation of Swadener Models.........................................................................................................9

5.

INDENTATION FRACTURE TECHNIQUE FOR THE DETERMINATION OF RESIDUAL STRESS (10)

*E-mail:wanghaidou@https://www.wendangku.net/doc/593718660.html,

Color versions of one or more of the ?gures in this article can be found online at https://www.wendangku.net/doc/593718660.html,/bsms.

77

Critical Reviews in Solid State and Materials Sciences,40:77–89,2015Copyright óTaylor &Francis Group,LLC ISSN:1040-8436print /1547-6561online DOI:

10.1080/10408436.2014.940442

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

6.CONCLUSIONS (11)

FUNDING .............................................................................................................................................................11REFERENCES (11)

1.INTRODUCTION

Residual stresses are readily generated by inhomogeneous heat treatment or local plastic deformation involving bulk sol-ids,1–3thin ?lms,4–6and coatings 7–9used in various industrial components.The existing residual stress ?eld in these compo-nents has a signi?cant effect on their performance such as mechanical properties,10fatigue strength,11wear and fracture properties,12,13etc.The existence of residual stress may be bene-?cial or detrimental,depending upon its value and the potential application.For instance,compressive residual stresses in the coatings can improve the adhesion and fatigue strength of the system,while high tensile stresses may cause cracking and fatigue failure.Thus,to measure and control accurately residual stresses is very important in both scienti?c and technological perspectives.

Various experimental techniques have been developed to measure the residual stresses in materials,such as X-ray dif-fraction,14hole-drilling,15layer removal,16neutron diffrac-tion,17synchrotron,18Raman spectroscopy,19ultrasonic method,20and magnetic method.21However,these methods all have some problems.For example,X-ray diffraction method is con?ned to crystals and inapplicable to amorphous materials.As the penetration depth of X ray is very shallow,the measurement depth is only about 30m m.Hole-drilling method is destructive to materials,and the measurement accu-racy is easily in?uenced by many factors such as aperture,hole depth,and bonding quality of strain gauges.Raman spec-troscopy and magnetic method are inapplicable to metals and non magnetics,respectively.Neutron diffraction and synchro-tron equipment are expensive and scanty,which are dif?cult to apply to actual production.The limitation of these methods drives the development of new measuring technology.

Nanoindentation is an instrumented indentation method,which is often used to extract the mechanical properties of bulk solids,thin ?lms,and coatings.22–28In addition,nanoindentation also can be used to estimate residual stresses in materials.In past decades,numerous studies have been conducted to determine residual stresses by nanoindentation.The in?uence of residual stress on various nanoindentation parameters such as hard-ness,29–31loading behavior,32–34unloading behavior,35–37con-tact area,34,37–39and pile-up,37,39–41has been investigated both experimentally and with ?nite element simulations.

The experiment carried out by Tsui et al.30showed that hardness calculated by standard methods decreased with ten-sile stress and increased with compressive stress.However,

the ?nite element analysis by Bolshakov et al.31revealed that the hardness was not always dependent of residual stress.For materials that are prone to pileup,the hardness is not signi?-cantly affected by residual stress when proper contact area is used.Based on that hardness is invariant regardless of the residual stress,Suresh et al.proposed a methodology to deter-mine the equibiaxial residual stress from the difference in con-tact area of stressed and stress-free materials indented to the same depth.42Lee et al.1developed a new model to evaluate the equibiaxial residual stress by combining stress relaxation with a shear plastic-deformation concept.This model ?tted the contact area as an equation of the third degree in the indenta-tion load to make the residual stress be only related to the indentation load.To overcome the limitation of the model to equibiaxial or uniaxial residual stress,Lee et al.43proposed a new indentation model,which can evaluate an arbitrary biaxial stress.Through ?nite element simulations,Xu et al.35,36pro-posed an empirical model,which is based on the effect of residual stress on the unloading curve of nanoindentation.It was found that the elastic recovery parameter h e /h max has a lin-ear relationship with the ratio of residual stress to yield stress s r /s y .Subsequently,the empirical model was applied to deter-mine the residual stress in a mechanically fused quartz beam.Swadener et al.44suggested that spherical indentation is more sensitive to stress effects than sharp indentation,and then developed two methods to measure biaxial residual stress.An alternative way to measure the residual stress is using indentation fracture technique,which is based on the classical fracture mechanics.45The residual stress can be estimated by comparing the crack lengths of indentations on stressed surfa-ces with those on stress-free surface.

This article reports on a brief description of different nano-indentation models to determine residual stress.The prerequi-site and limitation of these models are discussed.

2.BASIC PRINCIPLES OF NANOINDENTATION METHOD

Figure 1shows a typical load-depth curve consisting of load-ing and unloading.During loading,both elastic and plastic defor-mations occur as the permanent impression is generated.During unloading,only the elastic formation is assumed to be recovered,and reverse plastic deformation is usually negligible.46

Figure 2illustrates the unloading process and important parameters characterizing the contact geometry.At present,the Oliver method is commonly used to characterize the

78L.-N.ZHU ET AL.

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

hardness and elastic modulus based on the analysis of the load-depth curves.47,48The hardness H and reduced modulus E r are de?ned by

H D

P max c

(1)

E r D S ???p p 2b ?????A c

p ;

(2)

where P max is the maximum load,A c is the contact area,S D d P /d h is the contact stiffness at the initial unloading,and b is a constant which depends on the geometry of the indenter.The

reduced modulus E r is de?ned by

1r D 1?n 2C 1?n 2i

i

;

(3)

where E and E i are the elastic modulus of the specimen and the

indenter,respectively and v and v i are the Poisson’s ratio of the specimen and the indenter,respectively.

A crucial step in calculating the hardness and elastic modu-lus is the determination of the contact stiffness at the initial unloading and the projected contact area at the peak load.The unloading curve is usually well approximated by the power law relation:

P D a h ?h r eTm ;

(4)

where a and m are power law ?tting constants and h r is the residual depth after unloading.

The contact stiffness at the initial unloading can be obtained by differentiating Eq.(4)at the maximum depth h max :

S D

dP dh

h D h max

D a m h max ?h r eTm ?1:

(5)

The projected contact area can be calculated from the relation

A c D f h c eT;

(6)

where h c is the contact depth.Since the Oliver method assumes that the contact periphery sinks in,h c is always smaller than h max :

h c D h max ?e

P max

S

;(7)

where e is a constant that depends on the geometry of the indenter.

As the indenter generally deviations from perfect geometry,the area function is usually ?tted by

A c D X 8n D 0

C n h c eT2?n

D C 0h 2c C C 1h c C L C C 8h 1=128

c

;(8)

where C 0...C 8are constants determined by curve-?tting procedures.

Once the contact stiffness and contact area are determined,the hardness and elastic modulus can be calculated by Eqs.(1)–(3).

Work-of-indentation methods can also be used to measure a material’s hardness.49The hardness can be determined

based

FIG.1.A typical load-depth

curve.

FIG.2.Schematic illustration of the unloading process show-ing parameters characterizing the contact geometry.(óCam-bridge University Press.Reproduced with permission of

Oliver and Pharr.47Permission to reuse must be obtained from the rightsholder.)

RESIDUAL STRESS MEASUREMENT

79

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

on the total work and plastic work:

H W t D kP 3

max

9W 2t (9)H W p D

kP 3max

9W p

;(10)

where W t is the total work,W p is the plastic work,and k is a

constant equal to 0.0408for the Berkovich indenter.The total work and elastic work can be obtained by integrating the load-ing curve and unloading curve,respectively.The plastic work is the difference between the total work and elastic work.

Note that the Oliver method does not account for the pile-up of material at the contact periphery that occurs in some elastic-plastic materials.For pile-up,many correction methods have been proposed based on imaging the contact impres-sion.50–55

3.EFFECT OF RESIDUAL STRESSES

ON NANOINDENTATION RESPONSE 3.1.Effect on Mechanical Properties

Both experiments and ?nite element simulations were used to investigate the effect of residual stresses on nanoindentation response.Both hardness and elastic modulus were found to increase with compressive stress and decrease with tensile stress,30when the nanoindentation data were analyzed by stan-dard methods.However,the elastic modulus which is an intrinsic property of the material should not be affected by stresses.Subsequently,both experiments and simulations show that the properties measured according to standard meth-ods are inaccurate because pileup around the indentation is not accounted for in the contact area determination.Once the proper contact area is used,the hardness and elastic modulus are signi?cantly independent of stress.

3.2.Effect on Load-Depth Curves

The residual stresses signi?cantly affect load-depth curves.For a ?xed penetration depth,the loading curves for compres-sive stresses are higher than those for stress-free state,and conversely for tensile stresses.31,32,34,37,39,56–59Figure 3shows the effect of residual stress on loading curves.The compres-sive stress can constrain the indentation plasticity,thus leading to a higher indentation load than that for stress-free state.Sim-ilarly,the effect of tensile stress is opposite to that in compres-sive stress state by enhancing the indentation plasticity.

A similar behavior was found for the unloading curves which shifted to the left for compressive residual stress and right for tensile residual stress when compared with that of stress-free state.31,37,39Figure 4shows the ending part of unloading curves for indents made to a maximum depth of 700nm of copper single crystal with different residual stress states.Since the unloading process of nanoindentation is a

pure elastic process and the compressive stress in the material tends to push the indenter up more,more elastic recovery and smaller residual depth are induced.35While the tensile stress gives an opposite effect,thus leading to less elastic recovery and larger residual depth.

3.3.Effect on Pile-Up

It is well known that materials exhibiting low strain harden-ing tend to pile up around indents due to the

incompressibility

FIG.3.Loading curves for indents made to a maximum depth of 700nm of copper single crystal with different residual stress states.(óElsevier.Reproduced with permission of Zhu et al.39Permission to reuse must be obtained from the

rightsholder.)

FIG.4.The ending part of unloading curves for indents made to a maximum depth of 700nm of copper single crystal with different residual stress states.(óElsevier.Reproduced with permission of Zhu et al.39Permission to reuse must be obtained from the rightsholder.)

80

L.-N.ZHU ET AL.

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

of plastic deformation.60The amount of pile-up can be charac-terized by the height of the pile-up relative to the undeformed surface.It is shown that pileup is large when there are large compressive stresses in the materials,but relatively small for large tensile stresses.31,37-39For compressive stresses,the materials are pushed out to the surface of indenter,which results in more pile-up;whilst tensile stresses tend to pull the materials away from the surface of indenter to decrease the amount of pile-up.In addition to residual stress,pileup defor-mation behavior is related with the ratio h f /h max and work-hardening behavior.61The pile-up amount is large when h f /h max is close to 1and the degree of work hardening is small.When h f /h max is less than 0.7,very little pile-up occurs no matter what the work-hardening behavior of materials.3.4.Effect on True Contact Area

The residual stresses also have a signi?cant effect on the true contact area of indentation in pile-up materials.Numerous studies have shown that the true contact area has an almost lin-ear relationship with the residual stress and increases with increasing compressive stress,while it decreases with increas-ing tensile stress.31,35,37,62The different variation of true con-tact area with residual stresses is due to the fact that compressive stresses tend to increase the pile-up amount,thus increasing the true contact area,while tensile stresses gives an opposite effect to decrease the true contact area.

Determination of true contact area for pile-up material has been a hot and dif?cult research topic in recent years.Atomic force microscope is usually used to determine the true contact area.Kese et al.51proposed a semi-ellipse model to correct the contact area.Each pileup contact perimeter was approximated as projecting a semi-ellipse with major axis b and minor axis a i .Then the true contact area can be obtained as

A D A O-P C 5:915h c X

a i ;(11)

where A O-P is the contact area from the Oliver-Pharr method and a i (i D 1,2,3)is the width for 3pileup lobes.

Saha et al.53assumed that the piled-up material forms an arc around the edge of the indentation (three-arc model).Based on this assumption,Zhu et al.proposed a model to determine the true contact area.50The projected contact area can be modeled as an equilateral triangle bounded by three arcs,as shown in Fig.5.The true contact area A can be obtained as

A D 14:175

up

120sin u

2

?3cot u C ???3p

!h max C h ave

p 2:(12)

The pile-up width x can be de?ned as

x D R ?Rcos u 2D a 2sin u 21?cos

u

2

D 3:7651?cos u 2sin u

2

h max C h ave

p ;(13)

where h p and x can be determined from the pro?le of indents,as shown in Figures 6and 7.

Equating Eqs.(12)and (13),the true projected contact area A can be calculated.

Maybe there are other methods that can be used to measure the area of pile-up deformation,the above two models (semi-ellipse model and three-arc model)both have been used by other researchers.63,64However,a uni?ed method has not yet been formed.

In summary,residual stresses have signi?cant effect on load-depth curve,pile-up height,and true contact area.Thus,the state (tensile or compressive)of residual stress can be determined by comparing the load-depth curve,pile-up height,and true contact area of stressed material with those of stress-free reference material.Among the three parameters,it is easiest to obtain load-depth curve from nanoindentation data.However,only residual stress state can be qualitatively determined by simple comparison of load-depth curves for stressed and stress-free materials.To determine quantitatively the magnitude of residual stress in the materials,speci?c relationship between residual stress and nanoindentation parameters should be extracted from analyzing load-depth

curves.

FIG.5.Schematic representation of the projected contact area considering pile-up.(óElsevier.Reproduced with permission of Zhu et al.50Permission to reuse must be obtained from the rightsholder.)

RESIDUAL STRESS MEASUREMENT

81

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

4.NANOINDENTATION MODELS FOR THE DETERMINATION OF RESIDUAL STRESS

At present,there is no one set method that can be applied to the calculation of residual stress for all materials.In this sec-tion,six typical models usually used to quantitatively deter-mine residual stress from analyzing load-depth curves are discussed,including Suresh model,Lee models,Xu model,and Swadener models.

4.1.Suresh Model

The residual stresses (tensile or compressive)are assumed to be equibiaxial and the magnitude is uniform over a depth which is at least several times larger than the indentation con-tact diameter.The prerequisite of the model is that the material hardness H is unaffected by any pre-existing residual stresses.The relation between the residual stress s and the ratio of the real contact area A of material with residual stress to that of stress-free material A 0can be written as

s D H A 0

A ?1 for tensile stress (14)s D H 1?A 0

for compressive stress :(15)This model is based on the difference of contact area

between a stress-free material and the same material with residual stress.When indented to the same depth,the contact area of material with compressive stress is larger than that of stress-free material,while smaller for tensile stress.

Note that there is a coef?cient difference (sin a )between the calculation formulae for tensile stress and compressive stress.Because the effects of tensile stress and compressive stress on the indentation process are different,as shown in Figures 8and 9.It is obvious that s A is the difference of load in the z direction between the materials with and without tensile stress,while s A sin a is the difference of load in the z direction between the materials with and without compressive stress.Before calculating the magnitude of residual stress using the Suresh model,the residual stress state (tensile or compressive)should be determined from the loading curves for the stressed and stress-free specimens.Figure 10shows the loading curves for the stressed and stress-free 1045steels at a ?xed depth of 230nm.It is concluded that the residual stress in the stressed steel is compressive,because the material with compressive residual stress requires larger force to be indented to the same depth as the one without residual stress.65According to Eq.(15),the residual stress in the stressed steel was ?117§20MPa,which was in good agreement with that by the

traditional

FIG.6.Pile-up height h p

.

FIG.7.Pile-up width x.

82L.-N.ZHU ET AL.

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

XRD method (?114§32MPa).As the measuring depths for the indentation and XRD methods are different,the XRD results cannot provide a calibration standard for indentation testing,and only can be used as a reference.

Considerable efforts have been made to determine the resid-ual stresses introduced during the preparation of thermal spray-ing coatings.66–69The Suresh model has been con?rmed to be an attractive method,since it allows such residual stresses to be quickly measured in a small region with non-destructive man-ner and to be mapped across the coating thickness.29Note that the Suresh model is only valid for homogeneous coatings,and the calculated value is only an approximation for unhomogene-ous coatings containing micropores and microcracks,or

complicated phase structures.If the indentation location is close to micropores or microcracks,the indentation depth will increase.This will lead to the increase of contact area and decrease of hardness.As the contact area and hardness are char-acteristic parameters for the Suresh model,errors for the calcu-lated value of residual stress are bound to be produced.Therefore,in order to increase the accuracy of measurement,the location of indents should be selected through optical microscope or atomic force microscope to keep away from micropores or microcracks as far as possible.

The Suresh model also provides an accurate measure of residual stress in thin ?lms with unknown material properties.The study by Taylor et al.70showed that the residual stresses in the thin carbon ?lms calculated using the Suresh model agree well with the theoretical analysis.The Suresh model and classi-cal XRD technique were used by Atar 71to determine the resid-ual stresses in ceramic thin ?lms.The residual stresses obtained by the indentation method have been found to be three times higher than those of the XRD technique.As the XRD technique has certain errors in measuring residual stresses,thus it cannot be used to con?rm the accuracy of the Suresh model.

Although the Suresh model can be applied to various mate-rials,it has obvious disadvantages.The model is speci?c for sharp indenters,such as Berkovich or Vickers indenters,and is limited to equi-biaxial residual stresses.Moreover,the model requires a stress-free reference sample such as free-standing ?lm or coating,which is often dif?cult to produce.On the other hand,the residual stresses in free-standing ?lm or coat-ing cannot be completely released;the hardness values of the stressed sample or stress-free reference sample are not identi-cal.Thus,unavoidable errors cannot be diminished from an experimental

standpoint.

FIG.10.Loading curves for the stressed and stress-free 1045steels at a ?xed depth of 230nm.(óElsevier.Reproduced with permission of Zhu et al.34Permission to reuse must be obtained from the

rightsholder.)

FIG.8.Schematic of the role of tensile stress at the indented surface.(óElsevier.Reproduced with permission of Suresh and Giannakopoulos.42Permission to reuse must be obtained from the

rightsholder.)

FIG.9.Schematic of the role of compressive stress at the indented surface.(óElsevier.Reproduced with permission of Suresh and Giannakopoulos.42Permission to reuse must be obtained from the rightsholder.)

RESIDUAL STRESS MEASUREMENT

83

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

4.2.Lee Models 4.2.1.Lee Model I

In 2003,Lee et al.proposed a new model based on stress relaxation theory to determine equibiaxial residual stresses.Keeping the penetration depth constant,relax the residual stress from the initial value s r to zero.

The residual stress can be calculated from the stress-induced normal load and load difference between the materials with and without residual stress:s r D

3

2P 0?P 1eT2R 3P 41C R 2?R 3P 0eTP 31

C R 1?R 2P 0eTP 21C R 0?R 1P 0eTP 1?R 0P 0

;(16)

where P 0and P 1are the peak loads for the stress-free material

and the material with residual stress.R 0,R 1,R 2,and R 3are ?t-ting constants between the contact area and peak load.

4.2.2.Lee Model II

In 2004,Lee et al.proposed another model to calculate non-equibiaxial surface stresses.Six different stresses were applied to the specimens using a special apparatus and divided into four categories (see Table 1):uniaxial stress

(s r x ?0;s r y D 0,3#and 5#),equibiaxial stress (s r x D s r

y ?0,1#

and 6#),biaxial stress (s r x ?s r

y ?0,2#),and pure shear stress

(s r x D ?s r y ?0;4#).s r y can be expressed as k s r

x using a stress

ratio k ,i.e.k D s r y =s r

x ,where k ranges from ?1.0to 1.0.

The biaxial stress can be separated into an equibiaxial stress and a pure shear stress.As the pure shear stress has no effect on the indentation load,the measurement of biaxial stress can be simpli?ed as an equibiaxial problem.The biaxial stress can be calculated as

s r x D

3P 0?P 1eT

1C k eTA c

;

(17)

where P 0and P 1are the peak loads for the stress-free material and the material with residual stress.A c is the contact area of stressed material.Actually,Lee model I is the same as Lee model II when the stress ratio k D 1,namely,equibiaxial stress state.

4.2.3.Application of Lee Models

The nanoindentation tests were performed on the cross-sec-tions of stressed and unstressed thermal barrier coating (TBC)samples.72The unstressed sample was obtained by immersing the stressed sample in hydrochloric acid to dissolve the 304stainless steel substrate.The residual stress in the TBC was compressive since the coef?cient of thermal expansion of the TBC is less than that of metal substrate.As the indentations were performed on the cross-section of the TBC,the compres-sive stress applied on the indenter can be considered as a uni-axial stress.Thus,the residual stress in the TBC was calculated using Eq.(17),k D 0.The results showed that the compressive stresses in the top coat (TBC)decrease from the bonding coat (BC)/TBC interface to the top surface of TBC.It is obvious that the Lee model can evaluate the distribution of the residual stress in micro scales.

X.Zhao et al.57investigated the residual stresses in TBCs by photoluminescence piezospectroscopy (PLPS)and nanoin-dentation.The residual stresses obtained by nanoindentation have similar trend with those calculated from PLPS measure-ments.However,X.Zhao et al pointed out that the Lee model is only valid for a homogeneous material.As the TBC is far from homogeneous,the residual stresses calculated by nanoin-dentation are only approximation.

M.K.Khan et al.37determined the residual stresses in Al-cladding and Al 2024-T351by the Suresh and Lee models.The residual stresses from both of the Suresh and Lee models agree well with those from ?nite element simulation.The divergence of the residual stresses on the far ends of the com-pressive and tensile regions is due to that the Suresh model describes a nonlinear relationship and the Lee model considers linearity in these regions.

Like the Suresh model,the Lee models also require a stress-free reference sample,although non-equi-biaxial surface stress can be determined.In addition,the models are based on a stress-relaxation theory,i.e.,the residual stresses are deter-mined from the changes in applied load during stress relaxa-tion at ?xed indentation depth.However,the indentation process is often considered as an elasto-plastic problem and residual stress cannot be relaxed alone when keeping the depth invariable,because the stress-relaxation process can lead to a simultaneous change in the indentation load and depth.654.3.Xu Model

In 2006,Xu et al investigated the effect of equibiaxial residual stress on the elastic recovery of nanoindentation using ?nite element simulations.The results showed that the residual stress affects not only the real contact area but also the elastic recovery parameter,i.e.the ratio of elastic recovery to the maximum penetration depth,h e /h max .The h e /h max ratio has a

TABLE 1

Unstressed reference and six different stressed states.(óElsevier.Reproduced with permission of Lee and Kwon.43Permission to reuse must be obtained from the rightsholder)Stress state s r x (MPa)s r y (MPa)k D s r y =s r

x Reference 00Unstressed

1#?415?414 1.0(equibiaxial)2#?375?2480.66(biaxial)3#?40800(uniaxial)

4#?239231?1.0(pure shear)5#41400(uniaxial)6#

428

427

1.0(equibiaxial)

84

L.-N.ZHU ET AL.

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

linear relationship with the ratio of residual stress to yield stress,s r /s y ,as shown in Figure.11.In addition,the slope of the h e /h max vs.s r /s y depends only on the E /s y ratio.The fol-lowing equation can be used to relate the h e /h max ratio with the s r /s y ratio:

h e h max D ?a s r

s y

C b ;(18)

where a and b are ?tting constants,a is the slope of h e /h max vs.s r /s y curves,and b is the intercept of h e /h max vs.s r /s y curves at s r D 0.a depends only on the E /s y ratio,and the relation-ship between them follows a power law relationship:

a D 10:53

E

y

?1:25:(19)

Equations (18)and (19)are the empirical model to determine equibiaxial residual stresses.

In order to verify the above model,Xu et al.estimated the residual stress in the mechanically polished fused quartz beam.The fused quartz beam was ?rmly held in a three-point bending device.The obtained residual stress in the mechani-cally polished fused quartz beam is a compressive stress with the magnitude of 30MPa.

The Xu model does not require any reference sample with known stress state,such as stress-free sample,or any particular mechanical properties.However,it requires a special three-point bending device,which limits the practical applications of this method.Moreover,as the method relies on an accurate determination of the ratio of h e /h max ,experimental factors such as surface roughness will result in a great error in

determination of h e /h max ratio from the unloading curve of indentation.Besides,the Xu model may be just suitable for the determination of residual stress in very hard materials with low E /s y ratios and limits the application to very soft materials with high E /s y ratios,since the sensitivity of the h e /h max ratio to the residual stress is inversely proportional to the E /s y ratio of the material.4.4.Swadener Models 4.4.1.Swadener Model I

In 2001,Swadener et al presented two methods for making measurements of biaxial residual stress using spherical inden-tation.The model based on the fact that the indentation depth or contact radius at the onset of yielding is affected by the residual stress in a way that can be analyzed by Hertzian con-tact mechanics.The residual stress can be calculated by

s R s y

D 1?3:723p

E r a s y R

0;

(20)

where R is the indenter radius;a the contact radius;s y the

yield stress.Obviously,if s y is available,the residual stress can be determined by Eq.(20)with experimental measurement of (E r a /s y R )0,which can be determined using least squares regression curve ?ts of h r /h max D A 1C A 2log(E r a /s y R ),as shown in Figure 12.4.4.2.Swadener Model II

Swadener model II is based on the empirical Tabor relation-ship between hardness and yield stress,

H D C s y ;

(21)

FIG.11.Effect of residual stress on elastic recovery parame-ter h e /h max .(óTaylor &Francis.Reproduced with permission

of Xu and Li.36Permission to reuse must be obtained from the

rightsholder.)

FIG.12.Relationships between h r /h max and E r a /s y R at differ-ent residual stresses.(óCambridge University Press.Repro-duced with permission of Swadener et al.44Permission to reuse must be obtained from the rightsholder.)

RESIDUAL STRESS MEASUREMENT

85

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

where C is the constrain factor.For stressed materials,Eq.(21)should be rewritten as

H C s R D C s y :(22)

By establishing the variation of C s y with E r a /s y R through experiments in a reference material in a known stress state,then the residual stress can be calculated from measurements of hardness.

4.4.3.Limitation of Swadener Models

Swadener model I has an advantage that the measured depth at which yielding occurs is affected by the stress in a manner that can be analyzed by Hertzian contact mechanics.However,this model requires that the yield stress of materials be known in advance and that data be extrapolated outside the range of experimental accessibility.73

Swadener model II can be used to measure residual stresses in bulk materials to within 10–20%,but it cannot be easily applied to thin ?lms.73The stress-free reference specimen must be structurally identical to the tested speci-men if accurate residual stress measurements are to be made.Unfortunately,this is often dif?cult to achieve in practice.For bulk materials,there is no substrate in?uen-ces.However,the substrate greatly affects the measure-ment of thin ?lm residual stresses.The substrate effects can be alleviated when the indenter radius is on the order of or less than the ?lm thickness.

Table 2gives a comparison of the above six models.It is obvious that the models can characterize only equibiaxial stress or biaxial stress,while the stress along specimen depth cannot be obtained.Moreover,the six models all have limita-tions.Except Swadener model I,the other models requires a reference specimen,which is often dif?cult to obtain.For Swadener model I,although a reference specimen is not required,the yield stress must be determined by extra experiment.

5.INDENTATION FRACTURE TECHNIQUE FOR THE DETERMINATION OF RESIDUAL STRESS

When a brittle material is indented using a moderate force,a permanent impression is often formed with radially oriented cracks at the indent corner,as shown in Figure 13.74Based on the classic indentation fracture mechanics,the fracture tough-ness K c of elastic-plastic brittle materials is directly related to the indentation load P and the length of the radial cracks at the surface,c 0.For stress-free materials,the fracture toughness can be determined using the following expression:

K c D x P

c 3=20

;(23)

where x is the dimensionless residual stress factor which is related to the ratio of elastic modulus to hardness (E /H ).It is given by

x D ξ0cot u eT2=3E =H eT1=2;

(24)

where ξ0is a dimensionless constant,and u is the indenter half-angle.

For materials with preexisting residual stress s ,the fracture toughness is

K c D x P c §cs c 1=2;(25)

where c is a dimensionless constant which can be obtained from the crack shape,and c is the crack length for the stressed material.The ?rst term on the right hand of Eq.(25)is the stress intensity factor due to the indentation load,while the second term is the stress intensity factor due to the residual stress.Note that the second term is added to the ?rst term for tensile stress and subtracted for compressive stress.

TABLE 2

Comparison of six commonly used models to characterize residual stress

Models

Indenter type Characteristic parameters

Scope of application Limitations

Suresh model Sharp A Equibiaxial stress Require a stress-free reference sample Lee model I Sharp P Equibiaxial stress Require a stress-free reference sample Lee model II Sharp A Biaxial stress Require a stress-free reference sample

Xu model

Sharp h e /h max ratio Equibiaxial stress Requires a special three-point bending device Swadener model I Spherical E r a /s y R Biaxial stress Require known yield stress Swadener model II

Spherical

H

Biaxial stress

Require reference sample

86L.-N.ZHU ET AL.

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

For a given indentation load P ,the residual stresses can be determined by combining Eqs.(23)and (25):

s D K c 1?c 0=c eT

3=2

1=2"#

for tensile stress

(26)

s D ?K c 1?c 0=c eT

3=2

c c "#

for compressive stress :

(27)

The residual stress state can be de?ned by comparing c 0and c .The tensile stress can extend the cracks of the stress-free mate-rial (c 0>c ),while the compressive stress can shorten them.T.-Y.Zhang 75et al.proposed a semi-empirical formula to assess residual stresses in SiO 2and Cr thin ?lms deposited on Si wafers using indentation fracture technique.The residual stresses in the SiO 2and Cr ?lms were evaluated to be ?358and 1095MPa,respectively,which agree well with the theo-retical prediction.W.G.Mao 76et al.characterized the residual stress in a thermal barrier coating system by indentation frac-ture technique.The residual stress on the top coating varies from ?36.8to ?243MPa.

For the interface region between the coating and bond coat,the residual stress varies from ?5to ?30MPa.These results are in agreement with available data.

Indentation fracture technique can be used to determine residual stresses in bulk materials,thin ?lms and coatings.However,it is only applicable to brittle materials.Moreover,the dif?culty in measuring the crack length at nanoscale severely limits the accuracy of determination of residual stress using indentation fracture technique.

6.CONCLUSIONS

Residual stresses are increasingly desired to be measured using a nanoindentation technique.There is no one set method that appears to work for all materials.Six major models from analyzing load-depth curves and indentation fracture tech-nique have been developed.Unfortunately,the six models involving Suresh model,Lee model I,Lee model II,Xu model,Swadener model I,and Swadener model II all have limitations.The Suresh model and Lee model I are restricted to equi-biax-ial residual stress.Lee model II accounts for a general residual stress state but cannot describe the well-known nonlinearity.Xu model requires a special three-point bending device and limits the application to very soft materials with high E /s y ratios.Swadener model I requires that the yield stress of mate-rials be known.Swadener model II cannot be applied to thin ?lms.The indentation fracture technique is destructive and only applicable to brittle materials.Therefore,in order to eval-uate residual stresses accurately,new methods should be developed in the future.The methods with non-destructive and universal characteristic should be the research direction.

FUNDING

This article was ?nancially supported by NSF of Beijing (3120001),NSFC (51275105),and Distinguished Young Scholars of NSFC (51125023).

REFERENCES 1.Y.H.Lee and D.Kwon,Measurement of residual-stress effect by nanoindentation on elastically strained (100)W,Scripta Materi-alia 49,459(2003).

2.R.Unnikrishnan,K.S.N.Satish Idury,T.P.Ismail,A.Bhadau-ria,S.K.Shekhawat,R.K.Khatirkar,and S.G.Sapate,Effect of heat input on the microstructure,residual stresses and corrosion resistance of 304L austenitic stainless steel weldments,Mater.Character.93,10(2014).

3. F.Haag,D.Beitelschmidt,J.Eckert,and K.Durst,In?uences of residual stresses on the serrated ?ow in bulk metallic glass under elastostatic four-point bending-A nanoindentation and atomic force microscopy study,Acta Materialia 70,188(2014).

4.L.Zhang,H.Yang,X.Pang,K.Gao,and A.A.Volinsky,Micro-structure,residual stress,and fracture of sputtered TiN ?lms,Surf.Coatings Technol.224,120(2013).

5.S.K.Sharma and D.Y.Kim,Abnormal residual stress in nano-structured Al thin ?lms grown on Ti/glass substrates,Curr.Appl.Phys.13,1874(2013).

6.L.Zhang,H.Yang,X.Pang,K.Gao,and A.A.Volinsky,Micro-structure,residual stress,and fracture of sputtered TiN ?lms,Surf.Coatings Technol.224,120(2013).

7.Y.Y.Santana,P.O.Renault,M.Sebastiani,https://www.wendangku.net/doc/593718660.html, Barbera,J.Lesage,E.Bemporad,E.Le Bourhis,E.S.Puchi-Cabrera,and M.H.Staia,Characterization and residual stresses of WC-Co thermally sprayed coatings,Surf.Coatings Technol.202,4560

(2008).

FIG.13.Typical indent with radially-oriented cracks.(óElsevier.Reproduced with permission of Yen et al.74Permis-sion to reuse must be obtained from the rightsholder.)RESIDUAL STRESS MEASUREMENT

87

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

8. A.Dey,and A.K.Mukhopadhyay,Evaluation of residual stress in microplasma sprayed hydroxyapatite coating by nanoindenta-tion,Ceram.Int.40,1263(2014).

9.X.Zhang,M.Watanabe,and S.Kuroda,Effects of residual stress on the mechanical properties of plasma-sprayed thermal barrier coatings,Eng.Fract.Mechan.110,314(2013).

10.Y.Huang,S.Chang,and C.Chang,Effect of residual stresses on

mechanical properties and interface adhesion strength of SiN thin ?lms,Thin Solid Films ,517,4857(2009).

11.H.T.Kang,Y.Lee,and X.J.Sun,Effects of residual stress and

heat treatment on fatigue strength of weldments,Mater.Sci.Eng.A ,497,37(2008).

12.S.Novak,M.Kalin,P.Lukas,G.Anne,J.Vleugels,and O.Van

Der Biest,The effect of residual stresses in functionally graded alumina-ZTA composites on their wear and friction behaviour,J.Eur.Ceram.Soc.27,151(2007).

13.G.de Portu,L.Micele,S.Guicciardi,S.Fujimura,G.Pezzotti,

and Y.Sekiguchi,Effect of residual stresses on the fracture behaviour of notched laminated composites loaded in ?exural geometry,Compos.Sci.Technol.65,1501(2005).

14.O.P.Oladijo,A.M.Venter,L.A.Cornish,and N.Sacks,X-ray

diffraction measurement of residual stress in WC-Co thermally sprayed coatings onto metal substrates,Surf.Coatings Technol.206,4725(2012).

15.R.Sei?and D.Salimi-Majd,Effects of plasticity on residual

stresses measurement by hole drilling method,Mechan.Mater.53,72(2012).

16.M.Mahmoodi,M.Sedighi,and D.A.Tanner,Investigation of

through thickness residual stress distribution in equal channel angular rolled Al 5083alloy by layer removal technique and X-ray diffraction,Mater.Des.40,516(2012).

17.W.Woo,V.Em,P.Mikula,G.An,and B.Seong,Neutron dif-fraction measurements of residual stresses in a 50mm thick weld,Mater.Sci.Eng.A 528,4120(2011).

18. D.R.P.Singh,X.Deng,N.Chawla,J.Bai,C.Hubbard,G.Tang,

and Y.-L.Shen,Residual stress characterization of Al/SiC nano-scale multilayers using X-ray synchrotron radiation,Thin Solid Films 519,759(2010).

19.S.A.S.Rodrigues,A.G.Rolo,A.Khodorov,M.Pereira,and M.

J.M.Gomes,Determination of residual stress in PZT ?lms pro-duced by laser ablation with X-ray diffraction and Raman spec-troscopy,J.Eur.Ceram.Soc.30,521(2010).

20.Y.Javadi,M.Akhlaghi,and M.A.Najafabadi,Using ?nite ele-ment and ultrasonic method to evaluate welding longitudinal residual stress through the thickness in austenitic stainless steel plates,Mater.Des.45,628(2013).21.H.IlkerYelbay,I.Cam,and C.H.G €u r,Non-destructive determi-nation of residual stress state in steel weldments by Magnetic

Barkhausen Noise technique,NDT&E Int.43,29(2010).22.S.Suresh,A.E.Giannakopoulos,and J.Alcal a ,Spherical inden-tation of compositionally graded materials:theory and experi-ments,Acta Materialia 45,1307(1997).

23.T.A.Venkatesh,K.J.Van Vliet,A.E.Giannakopoulos,and S.

Suresh,Determination of elasto-plastic properties by instru-mented sharp indentation:guidelines for property extraction,Scripta Materialia 42,833(2000).

24. A.E.Giannakopoulos and S.Suresh,Theory of indentation of

piezoelectric materials,Acta Materialia 47,2153(1999).

25. A.Gouldstone,H.-J.Koh,K.-Y.Zeng,A.E.Giannakopoulos,

and S.Suresh,Discrete and continuous deformation during nano-indentation of thin ?lms,Acta Materialia 48,2277(2000).26. A.Rico,J.G o mez-Garc ?a,C.J.M u nez,P.Poza,and V.Utrilla,

Mechanical properties of thermal barrier coatings after isother-mal oxidation,Surf.Coatings Technol.203,2307(2009).

27.J.B.Cheng,X.B.Liang,Z.H.Wang,and B.S.Xu,Microstruc-ture and mechanical properties of FeBSiNb metallic glass coat-ings by twin wire arc spraying,J.Therm.Spray.Technol.22,471(2013).

28.J.B.Cheng,X.B.Liang,B.S.Xu,and Y.X.Wu,Characteriza-tion of mechanical properties of FeCrBSiMnNbY metallic glass coatings,J.Mater.Sci.44,3356(2009).

29.L.N.Zhu,B.S.Xu,H.D.Wang,and C.B.Wang,Microstruc-ture and nanoindentation measurement of residual stress in Fe-based coating by laser cladding,J.Mater.Sci.47,2122(2012).30.T.Y.Tsui,W.C.Oliver,and G.M.Pharr,In?uences of stress on

the measurement of mechanical properties using nanoindenta-tion:I.Experimental studies in an aluminum alloy,J.Mater.Res.11,752(1996).

31. A.Bolshakov,W.C.Oliver,and G.M.Pharr,In?uences of stress

on the measurement of mechanical properties using nanoindenta-tion:II.Finite element simulations,J.Mater.Res.11,760(1996).32.L.N.Zhu,B.S.Xu,H.D.Wang,and C.B.Wang,On the evalu-ation of residual stress and mechanical properties of FeCrBSi coatings by nanoindentation,Mater.Sci.Eng.A 536,98(2012).33.Y.H.Lee and D.Kwon,Residual stresses in DLC/Si and Au/Si

systems:Application of a stress-relaxation model to the nanoin-dentation technique,J.Mater.Res.17,901(2002).

34.L.N.Zhu,B.S.Xu,H.D.Wang,and C.B.Wang,Measurement

of residual stress in quenched 1045steel by the nanoindentation method,Mater.Character.61,1359(2010).

35.Z.H.Xu and X.Li,In?uence of equi-biaxial residual stress on

unloading behaviour of nanoindentation,Acta Materialia 53,1913(2005).

36.Z.H.Xu and X.Li,Estimation of residual stresses from elastic

recovery of nanoindentation,Philosoph.Mag.86,2835(2006).37.M.K.Khan,M. E.Fitzpatrick,S.V.Hainsworth,and L.

Edwards,Effect of residual stress on the nanoindentation response of aerospace aluminium alloys,Computat.Mater.Sci.50,2967(2011).

38. C.E.K.Mady,S.A.Rodriguez,A.G.G o mez,and R.M.Souza,

Effects of mechanical properties,residual stress and indenter tip geometry on instrumented indentation data in thin ?lms,Surf.Coatings Technol.205,1393(2010).

39.L.N.Zhu,B.S.Xu,H.D.Wang,and C.B.Wang,Effect of

residual stress on the nanoindentation response of (100)copper single crystal,Mater.Chem.Phys.136,561(2012).

40.X.Chen,J.Yan,and A.M.Karlsson,On the determination of

residual stress and mechanical properties by indentation,Mater.Sci.Eng.A 416,139(2006).

41.L.Ling,S.Long,Z.Ma,and X.Liang,Numerical study on the

effects of equi-biaxial residual stress on mechanical properties of nickel ?lm by means of nanoindentation,J.Mater.Sci.Technol.26,1001(2010).

42.S.Suresh and A.E.Giannakopoulos,A new method for estimat-ing residual stresses by instrumented sharp indentation,Acta Materialia 46,5755(1998).

88L.-N.ZHU ET AL.

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

43.Y.H.Lee and D.Kwon,Estimation of biaxial surface stress by

instrumented indentation with sharp indenters,Acta Materialia 52,1555(2004).

44.J.G.Swadener,B.Taljat,and G.M.Pharr,Measurement of

residual stress by load and depth sensing indentation with spheri-cal indenters,J.Mater.Res.16,2091(2001).

45.T.Y.Zhang,L.-Q.Chen,and R.Fu,Measurements of residual

stresses in thin ?lms deposited on silicon wafers by indentation fracture,Acta Materialia 47,3869(1999).

46.G.M.Pharr and A.Bolshakov,Understanding nanoindentation

unloading curves,J.Mater.Res.17,2660(2002).

47.W.C.Oliver and G.M.Pharr,An improved technique for deter-mining hardness and elastic modulus using load and displace-ment sensing indentation experiments,J.Mater.Res.7,1564(1992).

48.W.C.Oliver and G.M.Pharr,Measurement of hardness and

elastic modulus by instrumented indentation:Advances in under-standing and re?nements to methodology,J.Mater.Res.19,3(2004).

49.J.R.Tuck,A.M.Korsunsky,S.J.Bull,and R.I.Davidson,On

the application of the work-of-indentation approach to depth-sensing indentation experiments in coated systems,Surf.Coat-ings Technol.137,217(2001).

50.L.N.Zhu,B.S.Xu,H.D.Wang,and C.B.Wang,Determina-tion of hardness of plasma-sprayed FeCrBSi coating on steel sub-strate by nanoindentation,Mater.Sci.Eng.A 528,425(2010).51.K.O.Kese,Z.C.Li,and B.Bergman,In?uence of residual stress

on elastic modulus and hardness of soda-lime glass measured by nanoindentation,J.Mater.Res.19,3109(2004).

52.Y.H.Lee,U.Baek,Y.I.Kim,and S.H.Nahm,On the measure-ment of pile-up corrected hardness based on the early Hertzian loading analysis,Mater.Lett.61,4039(2007).

53.R.Saha and W.D.Nix,Soft ?lms on hard substrates—nanoin-dentation of tungsten ?lms on sapphire substrates,Mater.Sci.Eng.A 319–321,898(2001).

54.K.O.Kese,Z.C.Li,and B.Bergman,Method to account for true

contact area in soda-lime glass during nanoindentation with the Berkovich tip,Mater.Sci.Eng.A 404,1(2005).

55.L.N.Zhu,B.S.Xu,H.D.Wang,and C.B.Wang,Measurement

of mechanical properties of 1045steel with signi?cant pile-up by sharp indentation,J.Mater.Sci.46,1083(2011).

56.M.Qasmi,P.Delobelle,F.Richard,and A.Bosseboeuf,Effect of

the residual stress on the determination through nanoindentation technique of the Young’s modulus of W thin ?lm deposit on SiO 2/Si substrate,Surf.Coatings Technol.200,4185(2006).57.X.Zhao and P.Xiao,Residual stresses in thermal barrier coat-ings measured by photoluminescence piezospectroscopy and indentation technique,Surf.Coatings Technol.201,1124(2006).58. A.W.Warren,Y.B.Guo,and M.L.Weaver,The in?uence of

machining induced residual stress and phase transformation on the measurement of subsurface mechanical behavior using nano-indentation,Surf.Coatings Technol.200,3459(2006).

59.M.Nishikawa and H.Soyama,Two-step method to evaluate

equibiaxial residual stress of metal surface based on micro-indentation tests,Mater.Des.32,3240(2011).

60. A.E.Giannakopoulos and S.Suresh,Determination of elasto-plastic properties by instrumented sharp indentation,Scripta Materialia 40,1191(1999).

61. A.Bolshakov and G.M.Pharr,In?uences of pileup on the mea-surement of mechanical properties by load and depth sensing indentation techniques,J.Mater.Res.13,1049(1998).

62.Q.N.Meng,M.Wen,C.Q.Hu,S.M.Wang,K.Zhang,J.S.

Lian,and W.T.Zheng,In?uence of the residual stress on the nanoindentation-evaluated hardness for zirconium nitride ?lms,Surf.Coatings Technol.206,3250(2012).

63.X.Zhou,Z.Jiang,H.Wang,and R.Yu,Investigation on methods

for dealing with pile-up errors in evaluating the mechanical prop-erties of thin metal ?lms at sub-micron scale on hard substrates by nanoindentation technique,Mater.Sci.Eng.A 488,318(2008).64.Y.Sun,J.Liang,Z.Xu,G.Wang,and X.Li,Nanoindentation for

measuring individual phase mechanical properties of lead free solder alloy,J.Mater.Sci.19,514(2008).

65.Q.Wang,K.Ozaki,H.Ishikawa,S.Nakano,and H.Ogiso,

Indentation method to measure the residual stress induced by ion implantation,Nucl.Instrum.Meth.Phys.Res.B 242,88(2006).66.X.J.Lu,X.Wang,and P.Xiao,Nanoindentation and residual

stress measurements of yttria-stablized zirconia composite coat-ings produced by electrophoretic deposition,Thin Solid Films 494,223(2006).

67.Y.C.Yang and E.Chang,Measurements of residual stresses in

plasma-sprayed hydroxyapatite coatings on titanium alloy,Surf.Coatings Technol.190,122(2005).

68.M.Tanaka,M.Hasegawa,A.F.Dericioglu,and Y.Kagawa,

Measurement of residual stress in air plasma-sprayed Y 2O 3-ZrO 2thermal barrier coating system using micro-Raman spectroscopy,Mater.Sci.Eng.A 419,262(2006).

69. C.R.C.Lima,J.Nin,and J.M.Guilemany,Evaluation of resid-ual stresses of thermal barrier coatings with HVOF thermally sprayed bond coats using the Modi?ed Layer Removal Method (MLRM),Surf.Coatings Technol.200,5963(2006).

70. C.A.Taylor,M.F.Wayne,and W.K.S.Chiu,Residual stress

measurement in thin carbon ?lms by Raman spectroscopy and nanoindentation,Thin Solid Films 429,190(2003).

71. E.Atar,C.Sarioglu,U.Demirler,E.S.Kayali,and H.Cimeno-glu,Residual stress estimation of ceramic thin ?lms by X-ray dif-fraction and indentation techniques,Scripta Materialia 48,1331(2003).

72.J.Zhu,H.Xie,Z.Hu,P.Chen,and Q.Zhang,Cross-Sectional

residual stresses in thermal spray coatings measured by moir e interferometry and nanoindentation technique,J.Therm.Spray Technol.21,810(2012).

73. C.M.Lepienski,G.M.Pharr,Y.J.Park,T.R.Watkins,A.

Misra,and X.Zhang,Factors limiting the measurement of resid-ual stresses in thin ?lms by nanoindentation,Thin Solid Films 447–448,251(2004).

74. C.Yen,S.Jian,https://www.wendangku.net/doc/593718660.html,i,P.Yang,Y.Liao,J.S.Jang,T.Lin,and J.

Juang,Mechanical properties of the hexagonal HoMnO 3thin ?lms by nanoindentation,J.Alloys Comp.508,523(2010).

75.T.-Y.Zhang,L.-Q.Chen,and R.Fu,Measurements of residual

stresses in thin Films deposited on silicon wafers by indentation fracture,Acta Matererialia 47,3869(1999).

76.W.G.Mao,J.Wan,C.Y.Dai,J.Ding,Y.Zhang,Y.C.Zhou,

and C.Lu,Evaluation of microhardness,fracture toughness and residual stress in a thermal barrier coating system:A modi?ed Vickers indentation technique,Surf.Coatings Technol.206,4455(2012).

RESIDUAL STRESS MEASUREMENT

89

D o w n l o a d e d b y [A s t o n U n i v e r s i t y ] a t 06:14 11 F e b r u a r y 2016

不必太在意童安格原唱【不必太在意的歌词】

不必太在意童安格原唱【不必太在意的歌词】 是不是在找这首不必太在意的相关歌词?我这里有哦!下面是!就让小编来我来和你们一起去了解一下相关的资料吧,希望能对你有用哦! 不必太在意的歌词 歌曲:不必太在意 歌手:童安格专辑:一世情缘 别再徘徊沉寂的心灵 别再留恋破碎的回忆 大地迎春雷 抛弃你满腹的忧虑 缤纷的彩虹等着你 别再犹豫等待的心湖 别再沉迷过去的旧梦 暖暖的春风 走向那灿烂的天涯路

耀眼的阳光迎着你你不必太在意 也不必隐瞒自己 你要寻觅亮丽的彩云你不必太在意 也不必隐瞒自己 你要寻觅亮丽的彩云亮丽的彩云 别再犹豫等待的心湖别再沉迷过去的旧梦暖暖的春风 走向那灿烂的天涯路耀眼的阳光迎着你你不必太在意

也不必隐瞒自己 你要寻觅亮丽的彩云 你不必太在意 也不必隐瞒自己 你要寻觅亮丽的彩云 亮丽的彩云 你不必太在意 也不必隐瞒自己 你要寻觅亮丽的彩云 你不必太在意 也不必隐瞒自己 你要寻觅亮丽的彩云 亮丽的彩云 不必太在意的演唱者的信息 童安格,著名歌手、音乐人,1959年7月26日生于台湾高雄,是华语乐坛较早的实力派歌手。集作曲、作词、演唱于一身,是典型的浪漫主义爱情故事的发言人。他于1987

年获台湾最受欢迎男歌星奖。他1996年参加中央电视台春节联欢晚会,演唱歌曲《畅饮回忆》,是国内较早深受欢迎的实力歌手。与王杰、周华健、齐秦并称台湾四大天王(9194年)。童安格演唱过《把根留住》、《耶利亚女郎》、《其实你不懂我的心》等经典歌曲,2011年底,童安格以全新形象与著名的经纪公司点时唱片签约,并成为旗下主推艺人。目前,童安格在内地发展。2012年底,发行他的全新大碟。 感谢您的阅读!

公务员考试全流程

公务员考试全流程 Document number:BGCG-0857-BTDO-0089-2022

广州市直MM为大家解答本次广州市考相关问题 管理提醒:本帖被 the9sun 设置为精华(2011-10-26) 09年考公进入广州市直MM,混迹qzzn多年终上岸,目前在市直组织人事部门任职,直接参与招考各个环节。 此次我所属的单位也有参加招考,看到坛子上很多xdjm挺多疑问,为回报论坛,特为此次市考的面试、资格审查、政审等问题,为大家解答。知无不言 关于大家关心的几个问题,在此一并解答一下 一、资格审查需要准备哪些材料(所有资料都要带原件、复印件) 1. 应届毕业生: 必须带上:身份证+学生证+普通高校毕业生就业推荐表+暂缓协议 其他备用:户口本、计划生育保证书(如果没带就当场写) 2. 社会人员:

必须带上:身份证+户口簿+学历证书+学位证书。 2年经验人员必须带劳动合同;如果没有劳动合同,带上单位工作经历证明+社保记录盖章;如果没有合同又没有证明,带上社保记录盖章 社会人员:带上单位工作经历证明备用 3. 在国有单位工作,必须带单位同意报考证明。 在事业单位工作的事业编,必须带单位同意报考证明。 在事业单位的派遣或者合同制员工,不用带同意报考证明。 二、面试环节需要注意哪些: 大家都知道的就不说了,说几个具体的细节 1.考官一般有10-12人。正面面对而坐,面试时间一个人15-20分钟,4-5个题 2. 面试一般有主考官念题,只念一遍(所以要挺清楚)

3. 考试面前一般都有一张白纸和一只笔。因此允许短时间的思考和列提纲(不过建议不要思考时间太长,15-20秒则ok) 4. 面试着装:自己穿着觉着舒服的正装。现在夏天,男生适合短袖衬衣+西裤,建议不打领带;女生适合套裙或者短袖衬衣+西裤 5. 面试之后,一般会要求到其他办公室回避一下,大概过几分钟,就会把面试成绩当场宣布给你。等面试人员基本结束后,就可以大致算出各自排名了。 三、体检 1. 体检一般是面试后两三天就开始,广州市考有几个定点体检医院,一般是各单位就近选择 2. 体检每个项目由医生填写具体记录和项目结论“合格”或“不合格”。如果有单项不合格,一般是不会录用的。医院也是根据公务员录用的要求来填写是否合格 3. 体检一般第二天或第三天招考单位即可知道结果。不联系考生则为通过了,如果联系考生可能就是要复检

童安格歌曲歌词

童安格 爱与哀愁演唱:童安格 走在风雨中我不曾回头,只想让自己习惯寂寞。 如果在梦中没有你没有我,能不能够让自己不再难过。 爱并不会是一种罪过,恨也不会是一种解脱。 爱与哀愁对我来说象杯烈酒,美丽却难以承受;点一根烟喝一杯酒能醉多久,醒来后依然是我。 走在风雨中我不曾回头,只想让自己习惯寂寞。 如果在梦中没有你没有我,能不能够让自己不再难过。 爱并不会是一种罪过,恨也不会是一种解脱。 爱与哀愁对我来说象杯烈酒,美丽却难以承受;点一根烟喝一杯酒能醉多久,醒来后依然是我。爱与哀愁对我来说象杯烈酒,美丽却难以承受;点一根烟喝一杯酒能醉多久,醒来后依然是我。走在风雨中我不想回头,能不能够让自己不再难过。 把根留住演唱:童安格 多少脸孔,茫然随波逐流,他们在追寻什么。为了生活,人们四处奔波,却在命运中交错。 多少岁月,凝聚成这一刻,期待着旧梦重圆。万涓成水,终究汇流成河,像一首澎湃的歌。 一年过了一年,啊~ 一生只为这一天,让血脉再相连,擦干心中的血和泪痕,留住我们的根。 多少岁月,凝聚成这一刻,期待着旧梦重圆。万涓成水,终究汇流成河,像一首澎湃的歌。 一年过了一年,啊~ 一生只为这一天,让血脉再相连,擦干心中的血和泪痕,留住我们的根。 草原词曲:童安格演唱:童安格 小孩你问我是从哪儿来,我说那秘密挂在那朵云彩 我问你小孩,谁给你胸前的玉块,他说他不知是谁将它生了下来 小孩你问我为何要皱着眉,我说我曾经辜负一个姐姐 我问你小孩为何要流着泪,他说他心爱的小羊迷路没能回来 青山和绿湾,埋藏了所有的忧伤;天空和海洋,哪里才是梦乡。 那草原,那一片草原就是你我的家。那草原,那一片草原就是你我的家。 青山和绿湾,埋藏了所有的忧伤;天空和海洋,哪里才是梦乡。 那草原,那一片草原就是你我的家。那草原,那一片草原就是你我的家。 那草原,那一片草原就是你我的家。那草原,那一片草原就是你我的家。 小孩你问我何时会再有笑容,我说当我再看到姐姐的脸。 花瓣雨演唱:童安格 爱一个人可以爱多久,心痛到那里才是尽头,花瓣雨,像我的情衷。 誓言怎样说才不会错,拥抱到天明算不算多,花瓣雨,飘落在(我)身后。 花瓣雨,就像你牵绊着我,失去了你,只会在风中堕落。 你的谎言像颗泪水,晶莹夺目却叫人心碎,花瓣雨,飘落在(我)身后。 花瓣雨,就像你牵绊着我,失去了爱,只会在风中堕落。 你的谎言像颗泪水,晶莹夺目却叫人心碎,花瓣雨,飘落在(我)身后。 花瓣雨,就像你牵绊着我,失去了爱,只会在风中堕落。 花瓣雨,飘落在我身后。

公务员考试的流程

公务员考试的流程 一、确定为面试对象 公务员面试是在笔试之后进行,笔试合格者才能进入面试。面试由中央国家机关、省、市、县(市、区)组织部门、人事部门组织实施。笔试结束后,由人事考试机构统一划定笔试专业科目合格分数线和公共科目最低录用控制分数线,各级组织、人事部门在上线人员中根据各招考职位报考者的笔试成绩,从高分到低分按招考职位考录计划的1:3确定面试对象。面试成绩满分为100分,合格分为60分。 面试资格确定方法为: (一)确定笔试分数线 由人事考试机构按照录取1:3的比例,参照调剂因素、资格复核淘汰因素、体检、政审淘汰因素等,确定一个基本的分数线。 (二)成绩排名 上线考生的笔试成绩按照各个职位从高到低的原则排名,总分并列的,比较《行测》和《申论》合计分数,分数高者优先。名次并列情况重复计算。 (三)名单公示 按照规定,进入面试的考生名单和成绩排名情况应在网站上予以公布,接受考生和社会各界的监督,公示时间一般为5天,公示未结束不得举行面试考试,在公示期间如有考生被检举违纪,经查实后该考生将被取消面试资格,由后续考生顺序替补。 二、资格复审 面试前,对进入面试的报考人员须进行资格复核。考生一般会接到电话通知,复核地点在当地公布的指定地点。资格复核需要带齐下列手续: (一)20××年全日制普通高校应届毕业生应提供学校核发的就业推荐表、教育部学生司制发的《全国普通高校毕业生就业协议书》、身份证、原户籍等相关证件(证明)原件及复印件。 (二)社会其他人员应提供本人身份证、户口簿、学历、学位证书、单位同意报考证明等相关证件(证明)原件及复印件,按各级组织人事部门规定的时间、地点接受资格审核。 报考者不参加资格审核或提供的证件不全及所提供的证件(证明)与个人网上填报内容不相符者,不得参加面试,因此出现的空缺,在报考该职位的人员中从高分到低分依次替补。面试前3天,取得面试资格的人员如果放弃参加面试,并向报考机关同级组织、人事部门书面确定的,将在报考该职位未进入面试的人员中从高分到低分依次替补。报考公安警察、森林警察的,在资格复审时,同时进行体能测评。 (三)发放通知 经过以上几个环节后,人事考试机构将确定最终正式进入面试的考生名单,考生将得到正式的面试通知书或考试证件,并得到面试的地点、时间和注意事项的通知。

部编版七年级语文上册第四单元测试卷含答案

七年级(上)语文第四单元测试卷 总分:100分测试时间120分钟 温馨提示:你现在拿到的试卷满分为100分(含卷面3分),相信只要认真读题、仔细审题、规范答题,一定能够获得一个令自己满意的成绩。 一、语文积累与综合运用(25分) 1、古诗文默写(8分) (1)补写出下列名句中的上句或下句。(4分) ①,青山郭外斜。(孟浩然《过故人庄》) ②山光悦鸟性,。(常建《题破山寺后禅院》) ③何当共剪西窗烛,。(李商隐《夜雨寄北》) ④商女不知亡国恨,。(杜牧《泊秦淮》) (2)默写朱熹《观书有感》(4分) 诗题: ,。 ?。 2、阅读下面的文字,完成(1)--(3)题。(5分) 远方耸立着巍峨的山峰,迂回的小道蜿蜒盘旋,挑石工瘦骨lín()峋的背影在山间徘徊,我小心冀冀的往山下凝视,不免心惊肉跳,顿觉头晕目眩,山下白雾茏罩,我不禁纳罕是何时所集结的唯美杰作,难道是山峦chuò()泣所孕育的结晶? (1)给文中加点的字注音或根据拼音写汉字。(3分) lín()峋chuò()泣头晕目眩( ) (2)文中有两个错别字,请找出并改正:改为;(1分) (3)加点字“纳罕”在这里的含义是:(1分) 3、阅读下面这首小诗,完成(1)--(2)题(5分) 成功的花, 人们只惊羡它现时的明艳, 然而当初她的芽儿, 浸透了奋斗的泪泉, 洒满了牺牲的血雨。 (1)这首小诗选自《繁星?春水》,作者是,她是中国现代文学史上第一位著名女作家,她一步入文坛,便以宣扬“”著称。(2分) (2)你从这首诗悟出什么道理?(3分) 4、阅读下列材料,完成(1)--(3)题。(7分) “太阳,太阳,给我们带来七色光彩……我们到这七彩梦,走向未来”。我们几乎是唱

公务员管理科工作流程图

公务员管理科工作工作职责: 1、公务员考核工作 2、公务员奖励工作 3、组织实施公务员培训工作 4、公务员登记(统计)工作 5、公务员辞职审批工作 6、公务员辞退审批工作 7、综合工作 公务员管理科综合工作流程图

公务员考核工作 一、岗位职责 负责完善公务员考核审核制度,拟订并组织实施具体实施办法;负责公务员考核的审核、审批工作。 二、平时考核工作流程及要求 平时考核重点考核公务员日常表现、奖惩、违规违纪以及出勤情况,采取按季度由主管领导或组织人事(政工)部门定期对被考核人作出阶段性评价,填写《公务员平时考核表》,重点记录公务员每季度有关日常表现、奖惩、违规违纪、出勤等方面的异常情况,报地区公务员主管部门备案。 三、定期考核工作流程及要求 (一)定期考核采取年度考核的方式,在每年的11月份进行。 (二)被考核公务员按照职位职责和有关要求进行总结,并在一定围述职;认真总结一年来在德、能、勤、绩、廉等方面表现,填写《考核登记表》。 (三)主管领导在听取群众和公务员本人意见的基础上,根据平时考核情况和个人总结,写出评语,提出考核等次建议和改进提高的要求; (四)对拟定为优秀等次的公务员在本机关围公示; (五)由本机关负责人或者授权的考核委员会确定考核等次;

(六)将考核结果以书面形式通知被考核公务员,并由公务员本人签署意见。 (七)报送审核。各单位考核结束后,将《考核工作总结》,《考核审核备案登记表》和《年度考核中优秀、基本称职、不称职及未定等次中受处分人员》及《考核结果花名册》报送地区公务员局公务员主管部门(公务员管理科)审核备案。 (八)资料归档。年度考核结果复函文件、考核登记表归档保存。 公务员(工作人员)考核工作流程图

歌词

很好的歌词哦 玻璃鞋 又再想情形原来多公平谁人如能使我经常欢乐,也能使我哭恋爱是无形如童话精灵无形而能使我心情起伏反而感觉满足我愿为爱作牺牲耗尽了我的真完成童话内戏份现实纵使伤感,破碎公主的心玻璃折射那幻觉幻觉极迷人王子,从来未遇到灰姑娘天神从来未造出玻璃鞋还是相信恋爱幻觉童话拼合爱的方块假如存在幸福玻璃鞋假如神或上天肯安排期望给我只管看一眼只管穿一穿也愉快music 我愿为爱作牺牲耗尽了我的真完成童话内戏份现实纵使伤感,破碎公主的心玻璃折射那幻觉幻觉极迷人王子,从来未遇到灰姑娘天神从来未造出玻璃鞋还是相信恋爱幻觉童话拼合爱的方块假如存在幸福玻璃鞋假如神或上天肯安排期望给我只管看一眼只管穿一穿也愉快王子,从来未遇到灰姑娘天神从来未造出玻璃鞋还是相信恋爱幻觉童话拼合爱的方块假如存在幸福玻璃鞋假如神或上天肯安排成就一对可拥有一刹花一生积蓄我愿买期望跟你只管吻一吻只管想一想也愉快! 我只在乎你- 邓丽君 如果没有遇见你,我将会是在哪里?日子过得怎么样,人生是否要珍惜?也许认识某一人,过着平凡的日子。不知道会不会,也有爱情甜如蜜?任时光匆匆流去,我只在乎你。心甘情愿感染你的气息。人生几何能够得到知己?失去生命的力量也不可惜。所以我求求你,别让我离开你。除了你,我不能感到,一丝丝情意。如果有那么一天,你说即将要离去。我会迷失我自己,走入无边人海里。不要什么诺言,只要天天在一起。我不能只依靠,片片回忆活下去。任时光匆匆流去,我只在乎你。心甘情愿感染你的气息。人生几何能够得到知己?失去生命的力量也不可惜。所以我求求你,别让我离开你。除了你,我不能感到,一丝丝情意。任时光匆匆流去,我只在乎你。心甘情愿感染你的气息。人生几何能够得到知己?失去生命的力量也不可惜。所以我求求你,别让我离开你。除了你,我不能感到,一丝丝情意。 好心分手(国粤语合唱版) 王力宏 (女):是否很惊讶讲不出说话没错我是说你想分手吗曾给你驯服到就像绵羊何解会反咬你一下你知吗(男):也许该反省不应再说话被放弃的我应有此报吗如果我曾是个坏牧羊人能否再让我试一下抱一下(女):回头望伴你走从来未曾幸福过(男):恨太多没结果往事重提是折磨(女):下半生陪住你怀疑快乐也不多(男):被我伤让你痛(女):好心一早放开我从头努力也坎坷统统不要好过(男):为何唱着这首歌为怨恨而分手问你是否原谅我(女):若注定有一点苦楚不如自己亲手割破(男):回头吧不要走不要这样离开我恨太多没结果往事重提是折磨(女):下半生陪住你怀疑快乐也不多没有心别再拖好心一早放开我从头努力也坎坷统统不要好过

国家公务员考试报名流程官方回答

国家公务员考试报名流 程官方回答 LG GROUP system office room 【LGA16H-LGYY-LGUA8Q8-LGA162】

国家公务员考试报名流程官方回答 官方回答 一、申请报名 按照规定的程序和方法组织国家公务员录用考试的报名,是整个公务员录用考试实施流程的重要环节。也是国家公务员录用考试公开、平等原则的具体体现。公务员录用考试的报考于考试主管机关发布招考公告后进行。具体程序如下: (一)正式报名前,参加公务员考试的人员应在规定的时间和地点领取报名所需的各种表格和报考须知资料,认真填写好报名表并了解报考须知。 1.报名表的内容一般包括: (1)个人基本情况:姓名、性别、年龄、籍贯、住址、通讯地址、照片; (2)考试法规定的要求事项,如:有无不良的嗜好,是否受过奖惩或刑事处分等; (3)资历、资格事项:文化程序、工作经历、个人品德习惯、专长爱好、体格与健康状况等; (4)其他事项:婚姻状况、家庭状况、社会关系、个人负担等。 2.报考须知,是指导老先生如何报名的告示,也是对招考公告的详细说明。现把中央国家行政机关录用公务员报考须知的有关内容介绍如下: (1)报考对象 一般除部分京内紧缺专业及其职位允许京外具有城镇户口的全民所有制职工报考外,大多数专业及其职位均由京内城镇户口的全民所有制职工报考。

A.京内报考人员 其一,允许京内及地方党政机关、人大、政协、法院、检察院及全民所有制企事业单位的在职职工报考。 其二,允许档案存放京内有关交流中心,并保留全民所有制职工身份的职工报考。 其三,允许当年度春季毕业的外语、财会、计算机、考古专业研究生和有两年以上工作经历有关专业的北京高校研究生报考,有关京外生源研究生录用后的留京问题,由人事部解决。 其四,允许国务院军转办及双(退)办批准,1994年在京安置但尚未找到安置单位的营以下转业军官及复员军人报考。 其五,允许集体、民办、合资等单位中全民所有制职工报考。 其六,单位地处远郊区县的报考人员,须在报名时或招考过程中,按有关管理权限,出具人事或组织部门同意报考的介绍信或信函,未能出具的,视其情况决定是否允许报考。对允许报考者,贮存到人事部"备选人员库"中,待开来介绍信后,作为"备选人员"予以推荐。 其七,中小学及公安、劳改系统的报考人员,也须在报名时或招考过程中,按照管理权限出具市、部级等所属教育、人事部门同意报考的介绍信或信函。不能出具的,按前述"6"中的类似办法处理。 B.京外报考人员 其一,面向京外招考的部门,其招考对象应符合有关规定中关于京内紧缺专业或特殊工作经历的要求。 其二,京外报考人员均应为全民所有制在职职工。 其三,边远地区及中小学教师或某些特殊行业的京外报考人员,须出具所在省政府人事部门的介绍信。 (2)资格条件(上文已述)

放过自己庄心妍的歌词

放过自己庄心妍的歌词 放过自己是庄心妍演唱的一首动听伤感的情歌,这首歌曲深受大家的喜欢,是不是在找他的相关的歌词?下面是!我帮你整理了这首歌的歌词相关信息吧!希望能对你有用哦! 放过自己的歌词放过自己-庄心妍 词:林华勇曲:林华勇 你总是越宠越坏 我对你的关怀 都变成了伤害 爱不可能再重来 过程虽然精彩 但感觉已不在 就当我上辈子欠了你 就当这是今生的宿命 也许没有你 我才更爱惜自己 既然我感动不了你 我就放过我自己 你的骄傲和谎言是我离开的动力 既然我改变不了你 至少我可以放弃

分手时才发现我并没有那么爱你 爱不可能再重来 过程虽然精彩 但感觉已不在 就当我上辈子欠了你 就当这是今生的宿命 也许没有你 我才更爱惜自己 既然我感动不了你 我就放过我自己 你的骄傲和谎言是我离开的动力 既然我改变不了你 至少我可以放弃 分手时才发现我并没有那么爱你 既然我感动不了你 我就放过我自己 你的骄傲和谎言是我离开的动力 既然我改变不了你 至少我可以放弃 分手时才发现我并没有那么爱你 放过自己的演唱者信息庄心妍(Ada),1993年1月9日出生于广东省汕尾市,内地女歌手。

2012年10月29日,发行首支单曲《一万个舍不得》。2013年1月15日,荣获酷狗繁星网新声代歌唱比赛第二名,2013年3月13日,在酷狗音乐独家发行个人原创专辑《一万个舍不得》,2013年5月3日,发行单曲《心有所爱》,2013年6月13日,发行单曲《以后的以后》。 2015年11月8日,在沈阳铁西体育馆举办了自己的第一场甜妍蜜语演唱会。2016年1月5日,在河北体育馆举办了演唱会。2016年4月21日,酷狗首发数字专辑《做最好的我》。2016年10月7日发行第十张原创专辑《Touch Of Love》,包含《孤单坠爱》、《错误的邂逅》等六首主打歌曲。 庄心妍个人演艺经历2004年,一张来自2004年超级女声冠军安又琪的唱片,让庄心妍渐渐地喜欢并熟悉了音乐。 2007年,一首来自卫诗Jill的《可可》,让庄心妍开始慢慢的对粤语歌曲有另一种感觉。最初开始接触QQ音乐,后参加各种语音软件举行的小型K歌比赛,定期翻唱歌曲发布到网站上,后被致力音乐公司签约,成为歌手。签约之后发行了自己的首张EP《填密爱》。 2012年签约致力音乐。2012年10月29日发行首支单曲《一万个舍不得》,一炮走红;11月16日演唱酷狗主题曲《繁星点点》。2013年1月15日获酷狗繁星网新声代歌唱比赛第二名;3月13日酷狗音乐独家发行个人原创大碟《一万

2018年国家公务员考试报考步骤流程

2018年国考报名流程:本文介绍2018年国家公务员考试报考流程。2018年国考报考流程应提前了解,利于把握国考时间安排。 一、报考程序 (一)职位查询 各招录机关的招考人数、具体职位、考试类别、资格条件等,等到报名开始时,及时查阅《中央机关及其直属机构2018年度考试录用公务员招考简章》(此时尚未公布)。 报考人届时可以通过以下网站查阅《招考简章》: 中央机关及其直属机构考试录用公务员专题网站 人力资源和社会保障部门户网站 国家公务员局门户网站 对《招考简章》中的专业、学历、学位、资格条件、基层工作经历以及备注内容等信息需要咨询时,请报考人员直接与招录机关联系,招录机关的咨询电话可以通过上述网站查询。 有关报考政策、报名网络技术和考场考务安排等事宜的详细情况,请参阅《报考指南》。 (二)网上报名 考试报名主要采取网络报名的方式进行。报考人员可登录中央机关及其直属机构考试录用公务员专题网站进行网上报名,也可以通过人力资源和社会保障部门户网站或国家公务员局门户网站上的相关链接登录考录专题网站。 网上报名按以下程序进行: 1、提交报考申请 2、查询资格审查结果 3、查询报名序号 (三)报名确认 通过资格审查的报考人员需要进行报名确认。报名确认采取网上确认的方式进行,报考人员应于规定的期间内在所选考区考试机构网站进行网上报名确认及缴费。未按期参加报名确认并缴费者视为自动放弃考试。 (四)网上打印准考证 报名确认成功后,报考人员应于规定的期间内,登录所选考区考试机构网站下载打印准考证。打印中如遇问题,请与当地公务员考试机构联系解决。 (五)参加笔试 笔试的公共科目包括行政职业能力测验和申论两科。不指定辅导用书,可以参考2018年国家公务员考试一本通(中国出版集团现代教育出版社)。报考中央对外联络部、中央编译局、外交部、文化部、商务部、国家旅游局、国家外国专家局、全国友协、中国贸促会等部门日语、法语、俄语、西班牙语、阿拉伯语、德语、朝鲜语(韩语)、葡萄牙语等8个非通用语职位的人员,还将参加外语水平考试,考试大纲请在考录专题网站和相关招录部门网站查询。 报考中国银监会及其派出机构、中国证监会及其派出机构特殊专业职位的人员以及报考公安机关人民警察职位的人员还将参加专业科目考试,考试大纲请在考录专题网站,中国银监会、中国证监会、公安部网站分别查询。

30年经典歌曲歌词集锦

1、把根留住 多少脸孔茫然随波逐流 他们在追寻什么 为了生活人们四处奔波 却在命运中交错 多少岁月凝聚成这一刻 期待着旧梦重圆 万涓成水终究汇流成河 像一首澎湃的歌 一年过了一年 一生只为这一天 让血脉再相连 擦干心中的血和泪痕 留住我们的根 2、八月桂花香 将要入梦,几番起伏终不平到如今都成烟雨 今夜成空,宛若回首袖底风 幽幽一缕香飘在深深旧梦中繁华若景一生憔悴在风里 回头是无晴也无雨 明月小楼孤独无人诉情衷 人间有我残梦会醒 漫漫长路起伏不能由我 人海漂泊尝尽人情淡薄 热情热心换冷淡冷漠 任多少深情都像寂寞 人随风波只在花开花又落 不管世间沧桑如何 你已乘风去满腹相思都沉默只有桂花香暗飘过 3、白发亲娘 你可是又在村口把我张望 你可是又在窗前把我默想 你的那一根啊老拐杖 是否又把你带到我离去的地方娘啊,娘啊,白发亲娘 儿在天涯 你在故乡 娘啊,娘啊,白发亲娘 黄昏时候 晚风已凉 回去吧,我的娘 儿不能去为你添一件衣裳娘啊,娘啊,白发亲娘。 你可是又在梦中把我挂念 你可是又在灯下为我牵肠 你的那一双老花眼 是否又把别人错看成我的模样 娘啊,娘啊,白发亲娘 春露秋霜 寒来暑往 娘啊,娘啊,白发亲娘 朝思暮想 泪眼迷茫 责怪吧,我的娘 儿想你却不能去把你探望 娘啊,娘啊,白发亲娘 白发亲娘 4、别亦难 相见时难别亦(也)难 东风无力百花残 春蚕到死丝方尽 蜡炬成灰泪始干泪始干 啊!相见难 啊!别亦(也)难 蜡炬成灰泪始干 5、步步高 没有人问我过的好并不好 现实与目标哪个更重要 一分一秒一路奔跑 烦恼一点也没有少 总有人像我辛苦走这遭 孤独与喝彩其实都需要 成败得失谁能预料 热血注定要燃烧 世间自有公道付出总有回报 说到不如做到要做就做最好 世间自有公道付出总有回报 说到不如做到要做就做最好 步步高 6、草原牧歌 辽阔草原,美丽山冈,群群的牛羊 白云悠悠,彩虹灿烂,挂在蓝天上 有个少年,手拿皮鞭,站在草原上 轻轻哼着,草原牧歌,看护着牛和羊 年轻人啊,我想问一问,可否让我可否让我诉说

放过自己的说说150条

放过自己的说说150条 1、我决定,放过自己一会儿,太累了,暂时不去想工作上的事情,不去催促,客户的感受也不去在乎了,等我休息好了,精力充沛头脑清晰再去处理。 2、生活已经那么累了,不给自己太高的要求,太多的压力,不时学会给自己找退路,学会放过自己,反而算是善待了自己。 3、一个人,想得太多了,心累的是自己。一个人,追逐得多了,疲惫的是自己。 4、前面的路还很远,你可能会哭,可是必须要走下去,必须不能停。 5、喜欢阳光是因为它很暖暖到了心底暖去了不知名的疼痛。 6、我不敢多想,我怕那个以杯具作为结尾的收局。 7、到了最终仍然要分开,又何必再相遇相识相爱。 8、跟自己说声对不起,因为以往为了别人难为了自己。 9、白云从不向天空承诺去留,却朝夕相伴;风景从不向眼睛诉说永恒,却始终美丽;星星从不向夜晚许诺光明,却努力闪烁;咱俩从不向对方倾诉思念,却永远挂牵。 10、脆弱的人才会四处游说自己的不幸,坚强的人只会不动声色的越加强大。 11、人生路上,不妨试着转弯,看淡得失,善待自己,不为难他

人,也放过自己。得不到的回应,就学会转身,不属于自己的情,洒脱地放,拥有时珍惜,失去后不说遗憾。 12、你知道,什么都会过去的,无论什么。如果能够的话,尽量原谅他人,放过自己。 13、我不是不爱你了,只是把你永远的放在心里。 14、你问她想不想你时她会说不想,其实恰恰相反。 15、半梦半醒的梦境真实的让人难过。不想做梦。不要做梦。太累了。已经那么多事情让人疲乏结果自己的梦都不放过自己。醒过来的时候觉得负能量已经要爆炸了。 16、但愿有人看透你的逞强,给你一个最温暖的怀抱 17、世界上最心痛的感觉,不是失恋,而是我把心给你的时候,你却在欺骗我。 18、此刻的生活并不是我想要的,但确实是我自找的,所以活该也认了。 19、我最大的问题还是对自己不明晰,某些时刻不放过自己,某些时刻又太放纵自己,所以我大多数时候在矛盾里啃啃咬咬,咬累了就拍拍屁股走人,压根儿忘了自己啃咬的初衷。 20、如果你看到面前的阴影,别怕,那是因为你的背后有阳光。 21、如果生活中,有一个人想把你踩在脚下,不要以为生活错待了你。或许,还有十个人想要把你踩在脚下,只是你的强大,让他们没有机会伸出脚来。 22、此刻不玩命,将来命玩你,此刻不努力,未来不给力。

把“根”留住——议小学数学教学的“根”的问题

把“根”留住——议小学数学教学的“根”的问题 歌。”“让血脉再相连,留住我们的根!”这是香港著名歌星童安格经典歌曲《把根留住》里的几句歌词。细细品来,真是意味深长。 共同出力量,集中精力研究和编写了新课程。就在短短的三、四年里,全国所有地区、所有学校分批进入了实验区,百万名教师投入到了这场声势浩大的改革之中,全国所有的适龄儿童几乎一个不漏地在学习新课程、接受新教育、学做新公民。 “多少脸孔,随波逐流,他们到底在追寻什么?”是不是在盲目地追新、幼稚地从洋?还是在血脉相连中寻求发展?我想,这个答案是肯定的:这是一场具有深远意义的教育改革;是一次符合我国国情、借鉴外国经验、传承传统精华、血脉紧紧相连的一次大变革。也正是“万涓成水,汇流成河,像一首澎湃的歌。” “传统精华”是我们大中华的民族之“根”;“传承与创新”是我们大中华的改革之路。 我们都是小学数学教师,我们到底应该如何去随波逐流?如何才能真正有效地实施新课程,根据时代需要把小学数学教学工作做得更好?我认为首先要有“把‘根’留住”的思想观念。什么是小学数学教学的“根”呢?我想,小学数学教学的本质就是小学数学教学的“根”。如果我们在新课程实施中能够始终紧紧地把握好小学数学教学的本质性的问题,我们就真正抓住了小学数学教学的根本性问题。 那么,我们怎样才能把握好小学数学教学的本质性的问题呢?那就是要不断地通过学习,进一步理解和精通数学的基本概念,把握有效的数学思想,构建多样的思维方式,培育学生的数学精神;进一步理清“传承与创新”的教学改革发展思路,在基础中求创新。具体说来,我们要从以下五个方面去努力: 一、精通数学的基本概念。 小学阶段的数学概念是最基本的,但也是最重要的概念之一。我们要学生掌握这些基本概念,教师自己首先要精通这些概念。而且,我还认为,一个人他在小学阶段对数学概念能理解透彻,印象深刻,那么,对他将来比较顺利地学习数学,其效果是十分明显的。 据网上资料显示,在高等教育领域里,数学这门课程不仅仅只是理科生学习的,而是几乎所有专业的学生都要学数学,因为它是一门基础课程。还如,凡想在大学一二年级转专业的话,无论是理科类、文科类、医学类、工科类等等,“数学分析”这门课程是必考科目。更如,在高考中,数学是和语文、英语占有同等分数的重要地位,其课程的重要程度更是不言而喻。由此,我就想到,数学对一个小学生的发展前途是何等的至关重要。如果我们的教学对象在小学阶段就连基本的数学概念都搞不清楚,那么,他将来怎么会有能力去参与数学课程的后续学习?怎么能适应国家和社会对人才的选拔机制?等待他们的结果将会是什么? 这里我再举个小例子进一步说明这个问题:就在前几年,我县元济高级中学有个文科毕业生,姓名:胡玉婷。她报考的是文科,而她在高考中数学却得了满分。再加上她的其它几门学科

公务员考试录用流程

录用流程 https://www.wendangku.net/doc/593718660.html, 2009-07-22 14:44:30 国家公务员网 【字体: 大中小】 公务员录用考试的基本程序 公务员录用考试的程序,包括录用考试的准备、笔试面试的操作、笔试面试的评判等。本节侧重从国家行政机关(即用人单位)角度阐述公务员录用考试的基本程序,以让应试者“知彼知己”。让应试者“见树又见林”,明确面试在公务员录用考试中所处的位置,进一步加深对公务员面试的认识。 一、公务员录用考试的准备工作 公务员录用考试的准备工作是公务员录用考试得以进 行的前提,包括编制录用计划、发布空缺公告、考试公告、审查报考者资格等。 1 编制录用计划 公务员的录用计划是指国家行政机关根据实际工作需 要计划录用的公务员人数、专业、所需资格条件、招考范围等。编制录用计划的程序是由各用人部门向同级政府人事部门申报计划,然后由政府人事部门综合平衡后,编制本年度的录用计划,然后逐级报录用考试主管机关批准后实行。

目前,我国公务员录用计划的主要内容是:录用公务员的 总数、不同职位人数的分布、所需公务员的文化程度及数量等。编制公务员录用计划的前提:一是国家核定的机构的编制不满;二是国家批准有增干指标。编制录用计划是在国 家编制管理、综合平衡的前提下进行的,是录用考试的有效前提。 2 发布职位空缺公告 国家行政机关出现职位空缺,报同级政府人事部门批准纳入录用计划后,由公务员考试机构将所空缺的职位的单位、职位、数额等向社会公布,以便有资格者准备或应试。空 缺公告又叫招考公告,是公务员录用考试面向社会的第一步,一般都详细、具体、明确地列出录用机构、录用职位、所需文化程度、所需工作经历、工资待遇等等。空缺公告一般 都通过新闻媒介(报纸、电台、电视等)向社会发布。 3 发布考试公告 政府人事部门在实施公务员录用考试时,成立的临时或常设考试委员会,决定办理考试的具体事项,如:排定考试日程、确定考试地点、拟定考试公告等等。 考试公告是考试机构向社会发布的第二个公告,一般根据具体情况,不定期地发布,其内容一般包括:考试种类、考试科目;报名条件;报考的职位与数额;职务的待遇;

让我们来寻根 教案

让我们来寻根 第一课时 教学目标: 1通过“寻根的故事”“我是中国人”“歌曲欣赏”等活动渗透爱国主义教育,培养学生的民族自豪感和爱国热情。 2 通过讲述人类起源的神话传说让学生了解我国上下五千年的民间文化。 教学准备: 1 按照第74~75页的内容和第76~77页上的部分内容自制成多媒体课件。 2 课前请三位学生排练小品“寻根”。 3 课前请学生收集有关人类起源的神话传说。 教学过程: 一寻根的故事 1 小品导入:“寻根”。 (旁白一人,演员两人,男女各一名,男孩扮演华侨老人,女孩扮演其孙女。故事讲述的是老华侨年轻时因战乱被迫离开祖国,多年后重返故土之百感交加的感人场面。其中可用多媒体课件播放第一幕中的战乱的印象画面配以演员的表演,第二幕中播放《把根留住》的MTV,演员朗诵《回乡偶书》一诗。总之教师应在课前做充分的准备,将小品的感人之处充分表达出来,才能取得预期的教学效果。) 2 同学们,这个小品给我们讲述了一个什么故事?你从中感受到什么? 3 像这位老人一样的华侨华裔还有很多,可他们都和这位老人一样,在离开祖国多年后依然要回到祖国的怀抱,请听这样几个故事。 4 提问:这些旅居海外的华人为什么要千里迢迢地回来寻根?你能体会到他们的心情吗? 5 欣赏并跟唱MTV《我的中国心》。 二我是中国人 1 看到这么多海外华侨来到中国寻根,你们有什么感想? 2 是啊!祖国在一天天强大起来,作为一名中国人,我们心潮澎湃,热血沸腾,让我们高唱一首《中国人》,向世界证明我们将永远屹立在世界的东方!(播放MTV〈中国人〉) 三我们的根有多深 1 作为一名中国人,我们感到骄傲和自豪;作为一名华夏子孙,我们也应该了解我们五千年的文明甚至更早的故事。老师就很想知道咱们中国人最早最早的祖先是谁?自古以来,人们一直在思考着这个问题。在古代,由于缺乏科学文化知识,人们只能凭借想象创造出许多关于人类起源的神话传说!老师这里就有一个《盘古开天地》的故事,请看!(播放〈盘古开天地〉的动画片) 2听音乐,以小组为单位设计一个以“开天辟地”为主题的小舞蹈进行表演。评一评:哪个小组把盘古氏的那种雄伟气魄表现得更为出色! 3你还知道哪些关于人类起源的神话传说?说出来给大家听听,并将名称填写在书上。四歌曲欣赏〈龙的传人〉 1教师讲述〈龙的传人〉的故事。 2 让我们共同唱起这首歌,唱出我们每个华夏儿女的精神! 第二课时 教学目标: 通过本课时的学习,让学生了解到人类的进化过程,看到中华大地早期人类进化的轨迹;引导学生知道先民生活的情景,激发学生对考古的兴趣。

伤感语录夜

伤感语录夜 1、我不寂寞,我只是一个人而已,我的世界有我一个人就好,已经足够热闹。 2、生活简单就迷人,人心简单就幸福;学会简单其实就是不简单。晚安! 3、如果一个人的孤独让你学会成熟,那么我宁愿做一个长不大孩子,天天活在幸福当中。 4、谎言与誓言的区别在于,一个是听的人当真了,一个是说的人当真了。 5、一个人走,一个人睡,一个人思索,一个人沉醉。一个人忙,一个人累,一个人烦躁,一个人体会。 6、想哭就哭,想笑就笑,不要因为世界虚伪,你也变得虚伪了。 7、明明是我们的故事,却给了别人一个完美的结局。 8、窗外下着雪,泡一杯咖啡,握到它凉了,才知道又想起了你。我的期待你如何才能明白! 9、静静的坐在荧屏前,熟悉的打开曾经留下的片段。原来当初最纯真的自己,早已被遗忘在那段风逝的岁月中。

10、星光坠入你眼里,而你却落进我心里。 11、我待你如此温柔,你却说何必强求。 12、愿吹过我的风能再环绕着你,算是借风与你相拥。 13、愿你所有快乐,无需假装。愿你此生尽兴,赤诚善良。祝你岁月无波澜,敬我余生不悲欢。 14、一个人最大的缺点不是自私、多情、野蛮、任性,而是偏执地爱一个不爱自己的人。 15、辗转难眠,就这样睁眼到天亮,有时候觉得为什么要过这般日子,原来是自己太过死心踏地对一人罢了。 16、流过泪的眼睛,更明亮。滴过血的心灵,更坚强。 17、有时候,会有种莫名的无助,去又不知道为什么。 18、忘了从什么时候开始,习惯了夜生活的有条不紊,不知道从什么时候开始,害怕了一个人的夜晚。 19、时光飞逝,停在哪里休息,哪里都有真情体现,我们不能害怕欺骗,把自己的热情藏在心里。 20、亲爱的自己,不要抓住回忆不放,断了线的风筝,只能让它飞,放过它,更是放过自己。不管现实多惨不忍睹你都要固执相信这只是黎明前短暂的黑暗而已。

公务员考试全流程

广州市直M M为大家解答本次广州市考相关问题管理提醒:本帖被the9sun 设置为精华(2011-10-26) 09年考公进入广州市直MM,混迹qzzn多年终上岸,目前在市直组织人事部门任职,直接参与招考各个环节。 此次我所属的单位也有参加招考,看到坛子上很多xdjm挺多疑问,为回报论坛,特为此次市考的面试、资格审查、政审等问题,为大家解答。知无不言 关于大家关心的几个问题,在此一并解答一下 一、资格审查需要准备哪些材料?(所有资料都要带原件、复印件) 1. 应届毕业生: 必须带上:身份证+学生证+普通高校毕业生就业推荐表+暂缓协议 其他备用:户口本、计划生育保证书(如果没带就当场写) 2. 社会人员: 必须带上:身份证+户口簿+学历证书+学位证书。 2年经验人员必须带劳动合同;如果没有劳动合同,带上单位工作经历证明+社保记录盖章;如果没有合同又没有证明,带上社保记录盖章 社会人员:带上单位工作经历证明备用 3. 在国有单位工作,必须带单位同意报考证明。 在事业单位工作的事业编,必须带单位同意报考证明。

在事业单位的派遣或者合同制员工,不用带同意报考证明。 二、面试环节需要注意哪些: 大家都知道的就不说了,说几个具体的细节 1.考官一般有10-12人。正面面对而坐,面试时间一个人15-20分钟,4-5个题 2. 面试一般有主考官念题,只念一遍(所以要挺清楚) 3. 考试面前一般都有一张白纸和一只笔。因此允许短时间的思考和列提纲(不过建议不要思考时间太长,15-20秒则ok) 4. 面试着装:自己穿着觉着舒服的正装。现在夏天,男生适合短袖衬衣+西裤,建议不打领带;女生适合套裙或者短袖衬衣+西裤 5. 面试之后,一般会要求到其他办公室回避一下,大概过几分钟,就会把面试成绩当场宣布给你。等面试人员基本结束后,就可以大致算出各自排名了。 三、体检 1. 体检一般是面试后两三天就开始,广州市考有几个定点体检医院,一般是各单位就近选择 2. 体检每个项目由医生填写具体记录和项目结论“合格”或“不合格”。如果有单项不合格,一般是不会录用的。医院也是根据公务员录用的要求来填写是否合格 3. 体检一般第二天或第三天招考单位即可知道结果。不联系考生则为通过了,如果联系考生 可能就是要复检 四、政审 1. 政审一般在体检后大概10-15天进行

[jackson][从你的全世界路过 From your world through]歌词

从你的全世界路过 From your world through 2019-03-05 我希望有个如你一般的人 如山间清爽的风 如古城温暖的光 从清晨到夜晚 由山野到书房 只要最后是你 就好 …………①………… 词:何星烁/刘流 曲:何星烁/刘流 女:让我从何提起 日子充实空虚 空气弥漫孤寂 美好时光与你 相遇在意和伤害成正比 逞强太无底气 为爱改变自己 为你与世为敌

生命重拾意义 不甘我的世界 和你阴差阳错轻描淡写只成一道风景 念白:从你的全世界路过你就只路过了一次 却成了我的全部世界RapStar—— 男:每晚坐在电台 用熟悉的声音陪伴 你坐在我的身旁 却无暇我的呐喊 是你的离开让我成为 全台的笑柄 你说你想爬的更高 去看看那的风景 我放你走 忍痛撒开了你的双手 我举牌上街游走 我甘愿为你出糗 我为你付出一切 因为我曾对你承诺

没错我叫陈沫 最后却只能选择沉默你抱着我说 你把爱情献给了青春你说合适大于爱情结束了这段缘分 怪我太过幼稚 是我不够成熟 以后的路陪不了了小容你要幸福 我的猪头兄弟 你丫差不多就回来吧我明白你的绝望 我也明白你很爱她做她爱吃的食物 去看她看过的风景她已经走了兄弟 拜托你要醒醒 你给了他你的一切那不是她想要的 你说没她你不活了你这不开玩笑嘛

她和你相爱因为感动和你的陪伴 但她因为现实走了 请不要再去遗憾 女:为爱改变自己 为你与世为敌 生命重拾意义 不甘我的世界和你 阴差阳错轻描淡写 只成一道风景 男:荔枝姑娘不要难过要相信十八还在 那小子真的命大 他很快就会回来 我真的羡慕你们那 童话般的爱情 祝你们永远幸福平安仪器不再报警 抱歉了幺鸡 让你等了我太久太久我不会再让你路过 我会占为己有

公务员计算机岗位类专业考试

操作系统 1、计算机的硬件基本上由哪五大部分组成? 答:运算器、控制器、存储器、输入设备、输出设备。 2、运算器都可对数据进行哪两种运算? 答:算术运算和逻辑运算。 3、CAD、CAM、CAT、CAI都代表什么? 答:1、计算机辅助设计(CAD) 2、计算机辅助制造(CAM) 3、计算机辅助测试(CAT) 4、计算机辅助教学(CAI) 4、数据处理是指对数据的(收集)、(存储)、(加工)、(分析)、(传送)的全过程。 5、程序性语言分为(机器语言)、(汇编语言)、(高级语言)三类。 6、能举出哪些是高级语言、哪些是低级语言? 低级语言:汇编语言 高级语言:basic . cobol . c. foxbase等 7、操作系统可分为(批处理操作系统)、(分时操作系统)、(实时操作系统)三种操作系统。 8、解释型程序和编译型程序有什么不同?哪种程序产生目标程序?编译程序产生目标程序 9、DBMS是什么的?

答:DBMS 是数据库管理系统。 10、计算机系统由(硬件)系统、(软件)系统两部份组成。 11、软件系统分为(系统)软件、(应用)软件两部分。 12、操作系统的特征:(并发)、(资源共享)、(虚拟)、(异步)。 13、没有任何软件支持的计算机称为(裸机)。 14、操作系统的五大功能(处理机管理)、(设备管理)、(存储器管理)、(文件管理)、(提供友好的用户接口)。 15、操作系统发展的过程:(无操作系统)、(单道批处理系统)、(多道批处理系统)、(分时系统)、(实时系统)、(网络操作系统)、(分布式系统)。 16、Spooling系统是(批处理)系统。 17、批处理系统有两大特点(自动性)、(顺序性)。 18、批处理系统追求的目标是什么?不断提高系统资源利用率,提高系统吞吐量。 19、分时系统的特点(多路性)、(独立性)、(及时性)、(交互性)。 20、分时系统的主要目标?系统对用户的响应时间。 21、实时系统分为哪两类?并能举出这两类的例子。飞机飞行、弹道发射、预定飞机票、查询航班都是什么系统? 22、实时系统的主要特点是什么?(可靠性)、(多路性)、(独立性)、(及时性)、(交互性)。 23、个人计算机上的操作系统是(单用户多任务)操作系统。 24、计算机的应用领域包括什么?

相关文档