当前位置：文档库 › Acta Materialia 54 2006 4621–4631

Acta Materialia 54 2006 4621–4631

Precipitation kinetics and transformation of metastable phases in

Al–Mg–Si alloys

C.-S.Tsao

a,*

,C.-Y.Chen a ,U.-S.Jeng b ,T.-Y.Kuo

Nuclear Fuel and Materials Division,Institute of Nuclear Energy Research,P.O.Box 3-14,1000Wenhua Road,Longtan,Taoyuan 32546,Taiwan

National Synchrotron Radiation Research Center,Hsinchu 30076,Taiwan

Department of Mechanical Engineering,Southern Taiwan University of Technology,71005,Taiwan

Received 21November 2005;received in revised form 1June 2006;accepted 1June 2006

Available online 28August 2006

Abstract

In situ synchrotron small-angle X-ray scattering (SAXS)and transmission electronic microscopy were used to study the precipitation and transformation behaviors of metastable b 00and b 0phases of naturally aged Al–Mg–Si alloys,AA 6022,during continuous heating,and subsequent isothermal aging.A new SAXS analysis approach for the complex SAXS pro?les enabled a quantitative analysis of the structural evolution and the corresponding kinetics of the concurrent needle-like b 00and rod-like b 0phase transformations,of di?erent size characteristics.The stable cross-section and rapid length growth along the needles of b 00phase,and the radius growth of b 0phase during the temporal evolution were characterized well by the concomitant nucleation,growth and coarsening stages.For an alloy aged at 260°C,the b 00precipitates ($3.5nm in radius)and b 0precipitates ($10.5nm in radius)reached the coarsening stages at t =30and 210min,respectively.During the coarsening stage,the b 00precipitates dissolved partially into the matrix and transformed partially to the b 0phase,and then stabilized with the residual $65%precipitates.The same methodology was also applied to an Al–Mg–Si alloy,AA 6111,containing Cu.The b 00precipitates of AA 6111alloy aged at 180°C showed an inert radius ($1.8nm)and a growing length with aging time,and the longer incubation period of $60min observed in the early stage of precipitation,relative to AA 6022,was attrib-uted to the more natural clusters.

Keywords:Small-angle X-ray scattering;Aluminum alloys;Precipitation;Aging

1.Introduction

Al–Mg–Si alloys are much used in the aerospace and automotive industries,owing to the combined merits of low weight and good mechanical properties.The mechanical properties of the alloys are mainly attributed to the metasta-ble precipitate phases formed during arti?cial aging.A gen-erally accepted precipitation sequence of solution-treated Al–Mg–Si alloys during arti?cial aging is:a supersaturated solid solution (SSS)!GP-I zones !metastable needle-like b 00precipitates (or called GP-II zones;formed through the transformation of GP-I as nuclei)!metastable rod-like

(or lath-like)b 0precipitates !stable b phase.Numerous investigations [1–13]using transmission electronic micros-copy (TEM)and di?erential scanning calorimetry (DSC)have been conducted for the characterizations of nanostruc-tures and precipitation behavior of b 00precipitates in Al–Mg–Si alloys aged at $180°C.Nevertheless,the under-standing of b 00precipitation is still incomplete and limited.Most studies [14–19]of the nanoscaled b 0and b 00phases formed during higher-temperature aging have focused only on the qualitatively complex precipitation sequence and crystal structures.

Recently,small-angle X-ray and neutron scattering (SAXS and SANS),being e?ective tools for in situ studies of particles’nanostructural evolution in a bulk sample,have attracted certain attention [20–23].However,the

Corresponding author.

E-mail address:cstsao@https://www.wendangku.net/doc/9716792791.html,.tw (C.-S.Tsao).

https://www.wendangku.net/doc/9716792791.html,

Acta Materialia 54(2006)

4621–4631

application of SANS to the study of Al–Mg–Si alloy is still in an early stage,and provides only limited data[7]and rough analysis[24]of b00precipitates.Because the SAXS contrast between the precipitates(MgSi)and the Al matrix is very low,our previous SAXS study[25]using high-energy photons from a high-?ux synchrotron radiation source and the established analysis technique constitutes the?rst SAXS report on the temporal evolution of b00pre-cipitate structure in an AA6022Al–Mg–Si alloy,including radius,length and volume fraction.

In the present study,using the in situ synchrotron SAXS technique,the time-dependent SAXS pro?les measured can be characterized by two regimes:the Q>0.04A?à1regime contributed by needle-like b00precipitates of a typical radius of$3nm and the Q<0.04A?à1regime dominated by rod-like b0precipitates of a typical radius of$10nm. Due to the substantial di?erence in size,the two scattering contributions by b00and b0precipitates can be separated relatively well from the SAXS pro?les for a quantitative investigation of the kinetics of the two concurrent b00and b0transformations,each having its own process of precip-itation and dissolution,during arti?cial aging.The in situ SAXS result provides a basis for improving the current understanding of the transformation behaviors of the metastable phases in Al–Mg–Si alloys.

Generally,studies of Al–Mg–Si alloys focus on two aging temperatures:$180°C for b00precipitates and $260°C for b0as well as b00precipitates.In addition to the typical Al–Mg–Si ternary alloys(e.g.,AA6022alloy), Al–Mg–Si alloys containing Cu(quaternary alloys,e.g., AA6111alloy)have also attracted much interests in indus-trial research[6,11].Study of both AA6022and AA6111 aged at$180°C centers mainly on the comparison of pre-cipitate types[5].In the study reported here,we performed in situ SAXS for both AA6022and AA6111Al–Mg–Si alloys.We investigated the time-resolved nanostructural evolutions of b00and b0precipitates in AA6022alloy dur-ing a continuous heating process from room temperature (RT)and the subsequent isothermal aging at260°C;the natural aging e?ect at RT was also included[1,9,10,26]. The corresponding precipitation and dissolution kinetics of the concurrent b00and b0phase transformations are quantitatively established.The temporal evolutions of the precipitate size and volume fraction in the precipitation process for each metastable phase can be well characterized by the concomitant nucleation,growth and coarsening stages proposed in the classic theory[27]and numerical modeling[28–31].A comparison of structural evolutions of the b00precipitates with aging time in AA6022and AA6111alloys aged at180°C is also presented.TEM observations of the same AA6022and AA6111alloy spec-imens studied by SAXS complement and con?rm the SAXS analysis.

2.Experimental

Al–Mg–Si alloys AA6022and AA6111were received from Alcoa Inc.,USA,in the form of$1mm thick sheets. The as-received sheets had been homogenized,hot rolled, cold rolled and then commercially heat-treated with the temper designations of6022-T4E29and6111-T43.The?ne grains serving as the matrix do not contribute to the SAXS pro?le because of no scattering contrast e?ect.The compo-sition(wt.%)of the alloys in this study were:0.58Mg,1.15 Si,0.13Fe,0.06Cu and0.06Mn for AA6022alloy;and 0.75Mg,0.9Si,0.4Fe,0.7Cu and0.3Mn for AA6111 alloy.

Before SAXS measurements,the sample sheets were solution-treated at560°C for40min,and subsequently quenched into ice water.Quenched samples were naturally aged for30days at RT.The SAXS specimens were prepared into1cm·1cm area and an optimum thickness of0.5mm by cutting the sheets and grinding.These specimens,?xed inside a small furnace with air-circulation cooling,were then heat-treated for combination with in situ SAXS mea-surements.The heat treatments of the SAXS specimens are listed in Table1.The SAXS measurements were con-ducted using the SAXS setup at the BL01B beamline of the National Synchrotron Radiation Research Center (NSRRC),Taiwan.The experimental details and advanta-ges of in situ SAXS using the high-energy,high-?ux syn-chrotron radiation X-ray source were described in our previous SAXS study[25].The in situ SAXS data were col-lected during a heating process from RT and the subsequent isothermal aging.During the isothermal aging,typical SAXS data were collected continuously on the basis of each frame/30min.The standard deviation of the SAXS data collected during the isothermal aging was typically within ±2%due to the30min counting interval and the high inten-sity,while the standard deviation of the SAXS pro?les col-lected during the heating process(usually5min counting interval)was within±20%.The standard deviations(shown as error bars in some of the?gures presented)decrease sig-ni?cantly with the increase of the SAXS intensities.In gen-eral,the high-Q SAXS data at low heating temperatures have larger error bars.All the SAXS scattering pro?les I(Q)were measured in an absolute scattering scale[25],with the scattering vector Q=4p sin(h/2)/k de?ned by the scat-tering angle h and the X-ray wavelength k.

The use of15keV synchrotron photons here cannot enhance any nucleation or precipitation.The radiation-induced or radiation-enhanced precipitation is caused by

Table1

Heat treatments of the specimens conducted for SAXS measurements

Alloy type Heat treatment

AA6022Continuous heating process from RT to260°C with a rate5°C/min,then followed by isothermal aging at260°C for720min AA6111Continuous heating process from RT to180°C with a rate5°C/min,then followed by isothermal aging at180°C for400min 4622 C.-S.Tsao et al./Acta Materialia54(2006)4621–4631

striking atoms out of the lattice sites,thus creating vacancies. The condition for attaining such e?ects[32]requires massive and energetic particles of at least hundreds of keV,whereas the photon energy used for SAXS is only15keV.

TEM examination was performed using a JEM2000FX at200kV.The TEM specimens were prepared by cutting a small piece from the samples,mechanically grinding to60–80l m thickness and then jet polishing in a solution of 30vol.%HNO3and70vol.%CH3OH atà20°C.Di?rac-tion contrast was applied to image the particle size.The TEM observations were conducted for both the AA6022 and AA6111samples without and with the aging treat-ments used for the SAXS measurements.

3.Results and discussion

3.1.Structural evolution and precipitation kinetics of b00and b0phases during continuous heating

The time-dependent SAXS pro?les measured for the naturally aged AA6022alloy during the heating process from RT to260°C are selectively presented in Fig.1(a), together with that for the subsequent isothermal arti?cial aging at260°C for30min.Note that the SAXS pro?le obtained for isothermal aging at260°C is of an intensity four times higher than that observed for the same sample aged at180°C[25],which is consistent with the reported SANS data[24].The SAXS pro?les measured during con-tinuous heating from RT to211°C were nearly the same, indicating no observable structural change.During the heating from RT to211°C,the power law scattering of Qà4in the low-Q region corresponds to the asymptotic scattering behavior of other large particles.This type of large particles are constituent or segregated particles from the Fe and Mn impurities.Their estimated size is at least close to the scale of micrometers.The SAXS intensity in the intermediate-Q region can be attributed to the scatter-ing from the clusters formed during natural aging.These natural aging clusters were also con?rmed by our TEM work.The observed natural aging clusters are spherical particles of roughly2–5nm in diameter.The cut-o?image detection limit using the di?raction contrast here is $1.5nm for the crystalline specimens.

During heating from211to260°C,the SAXS pro?le intensities increase with temperature in the intermediate-to high-Q region(Q P0.05A?à1),indicating a nucleation and growth of b00precipitates.(Note that this Q region is almost entirely contributed by the scattering of b00precipi-tates as mentioned in Section1.)In contrast,the corre-sponding heat?ow due to the formation of b00precipitates was observed at240–260°C in previous DSC studies [1,2,6,11].The SAXS pro?les collected for the range235–260°C and the subsequent isothermal aging at260°C for 30min are nearly the same in the intermediate-to high-Q region,implying the development of b00precipitates enters a coarsening stage(i.e.,no change in volume fraction according to the well-known LSW theory[27]).

Above235°C,the SAXS pro?le intensity in the low-Q region,dominated by newly formed large precipitates, increases with temperature and aging time,and changes gradually from the behavior of I(Q)μQà4(at RT)to I(Q)μQà2.1.The Qà4dependence in the low-Q region

is Fig.1.(a)Selected time-dependent SAXS pro?les measured for the naturally aged alloy AA6022during continuous heating from RT to260°C,together with that obtained during subsequent isothermal arti?cial aging at260°C for30min.(b)The SAXS pro?le obtained at RT is subtracted from the measured SAXS pro?les corresponding to(a)to remove the contribution of natural aging clusters.The solid lines are the intensities calculated from the model?ttings.(The abscissa is scattering vector Q.The ordinate is SAXS intensity expressed by macroscopic cross-section per sample volume.)

C.-S.Tsao et al./Acta Materialia54(2006)4621–46314623

attributed to the additional large particles formed at RT, which do not vary with aging time and the heating process, as explained in Section3.3below and in a previous study [25].The transition of the scattering characteristics is mainly due to the nucleation and growth of the rod-like b0precipitates of a much larger size than the b00precipitates formed concurrently.The large b0precipitates were con-?rmed as the main precipitates during aging at260°C in many previous TEM studies[15–18].These TEM studies also reported that the needle-like b00precipitates coexist with the rod-like(or lath-like)b0precipitates in the initial period of aging.

To remove the scattering contributions from the natural aging clusters and other large particles existing prior to the heating process,the time-resolved SAXS pro?les shown in Fig.1(a)are processed by subtracting the SAXS pro?le measured at RT.The resulting SAXS pro?les shown in Fig.1(b)are mainly attributed to the contributions from the b00and b0precipitates[24,25].Here,we have used the assumption that the natural aging clusters and other large particles are inert during the heating process and the subse-quent isothermal aging.This assumption neglects the small fraction of natural aging clusters which indeed dissolved during the heating and/or the arti?cial aging,and result in a slightly over-subtraction e?ect.Nevertheless,the over-subtraction e?ect is increasingly smaller for the SAXS pro?les measured at later times,where the b00and b0precip-itates contribute more and more.Therefore,during heating at211–235°C,the b0precipitates being supposed insigni?-cant,we model the corrected SAXS intensity from the b00 precipitates formed during heating at211–235°C with thin cylindrical particles:

I b00eQT?geD qT2V P~PeQTtBe1Twhere the contrast D q is the scattering length density di?er-ence between precipitates and matrix,g is the volume frac-tion of b00precipitates,V P is the volume of the cylindrical particles of radius R and length L and B is the constant incoherent background contribution.The normalized form factor~PeQT[20]for cylindrical particles,averaged in orien-tation,can be expressed as

~PeQT?

Z p=2

0sin QL

cos u

àá

QL cos u

2J1eQR sin uT

QR sin u

sin u d u

e2T

where J1is the?rst-order Bessel function.The radius and length extracted from the model?tting of Eq.(1)are 3.1±1.0nm and18.3±18nm,respectively,which are consistent with those obtained from the previous SAXS analysis of b00precipitates in AA6022alloy aged at 180°C[21],and the TEM studies[1,2,5–7]reported previ-ously.The uncertainties of the radius and length are the standard deviations obtained from a non-linear least-squares data?tting process(v2optimization).The calcu-lated SAXS pro?le using the structural parameters agrees well with the measured SAXS data,as shown in Fig.1(b).

For the SAXS pro?les collected above235°C,the scat-tering contribution from b0precipitates is increasingly important as the aging time increases,and has to be taken into account together with that from the b00precipitates. The scattering contribution from the b00precipitates, dominating the intermediate-to high-Q region(0.0456 Q60.1A?à1)of the SAXS pro?les(mentioned previously) can be approximated by

IeQT/

expeàR2Q2=4T

in the intermediate-Q region,2p/L6Q6p/R(Kratky–Porod approximation)[21],according to Eqs.(1)and(2). Note that this scattering contribution is closely related to the radius of b00precipitates.On the other hand,the scatter-ing pro?le in the low-Q region,0.016Q60.045A?à1,is dominated mainly by the scattering pro?le of large b0pre-cipitates(where the pro?le relates closely to the radius of the rod-like b0precipitates with a radius R P80A?).The scattering pro?le in the low-Q region contributed by the length of the b00precipitates is a relatively slow-varying pro?le.As shown in Fig.1(b),the calculated scattering pro-?les of needle-like b00precipitates with the same R=3nm but L=50nm(dotted line),200nm and300nm(dashed lines)in the low-Q region do not vary much with the length.Therefore,the SAXS pro?les in this low-Q region can be considered as the sum of the contributions mainly from the radius of larger b0precipitates as well as the length of b00precipitates.For the SAXS analysis presented below,we can extract the time-dependent structural parameters of the concurrent b00and b0precipitates at the same time by the method of model?tting.

Technically,the SAXS intensity from the needle-like b00 and rod-like b0precipitates formed above$235°C can be approximated by extending Eq.(1)for b00phase with the Kratky–Porod approximation for b0phase as follows:

IeQT?N b0eD q b0T2

V b0p R2

expeàR2

Q2=4T

tgeD qT2V P~PeQTtB

?g b0eD q b0T2

p R2

expeàR2

Q2=4TtgeD qT2V P~PeQTtB ?

C p R2

expeàR2

Q2=4TtgeD qT2V P~PeQTtBe3T

where the pre-factor C relates to the scattering contrast D q b0and volume fraction g b0of the rod-like b0precipitates, with radius R0,particle volume V b0and number density N b0.The precipitate composition usually remains a con-stant during the classical nucleation,growth and coarsen-ing.Therefore,the pre-factor C can be regarded as a relative volume fraction index of the b0phase.

Some TEM studies[15–17]pointed out that,in addition to b0precipitates,some other types of metastable precipi-tates,denoted as b0A,b0B and b0C,could coexist in the excess Si-type Al–Mg–Si alloy(e.g.,the AA6022alloy used).Nevertheless,all these types of precipitates have

4624 C.-S.Tsao et al./Acta Materialia54(2006)4621–4631

similar morphologies and sizes(lath-like or rod-like), except the crystal structures.The radius of the b0precipi-tates observed by our TEM work(see Section3.2)is con-sistent with the sizes observed by other TEM studies[15–17].Therefore,the di?erent types of b0precipitates can all have similar SAXS pro?les,but with di?erent scattering contrasts(for di?erent scattering intensities)arising from the di?erent crystal structures.The SAXS intensity from all the types of b0precipitates can be approximated in this study by a convoluted pro?le with an e?ective contrast.

The radii of b00and b0precipitates,R and R0,extracted from the model?tting using Eq.(3)for SAXS data of the AA6022alloy collected during heating at235–260°C and the subsequent isothermal aging at260°C are summarized in Table2.The model-?tted length of b00precipitates increases largely during the heating process from18.3nm at211–235°C to150nm at235–260°C,and then shows a continuous growing trend during the aging at260°C. From the calculated scattering pro?les(the dotted and dashed lines in Fig.1(b)),the model-dependent?tting in the measured Q range may extrapolate a large length of 150nm with a large uncertainty.The model-?tted values for b0precipitates are also greater than150nm with a large

uncertainty.The calculated SAXS pro?les simulated well the measured SAXS data,as shown in Fig.1(b).Note that the temporal evolution of the model-?tted values for the b00 precipitates reveals an inert radius and a rapid growing length with aging time.The temporal evolutions of the rel-ative volume fractions obtained from the model?tting for b00and b0precipitates are shown in Fig.2(also see Table2). The relative volume fraction of b0precipitates is deter-mined by the?tted pre-factor C values of the Kratky–Porod term in Eq.(3).

In the present study,the volume fraction for each phase is normalized by the maximum value during the continuous heating and the isothermal aging.The structural evolutions of b00and b0precipitates during the continuous heating in terms of size and volume fraction can be characterized by the early stage of a typical precipitation,i.e.,the concomi-tant nucleation and growth[27–31].From Fig.2,this in situ SAXS measurement detects the b00and b0precipita-tions at a slightly earlier temperature than those observed by DSC[1,2,6,11]and TEM[17]measurements.

3.2.Phase transformation kinetics of b00concurrent with b0 phases during isothermal aging at260°C

The time-dependent SAXS pro?les measured during iso-thermal arti?cial aging at260°C(up to210min)are?tted using the same Eq.(3)for the time-dependent structural parameters of the b00and b0precipitates in the isothermal aging.The?tted data are selectively presented in Fig.3(a). We have also carried out model-independent Kratky–Porod approximations(solid lines in Fig.3(b))in the di?erent Q regions corresponding to the b00and b0regimes for the rep-resentative SAXS pro?les collected during the arti?cial aging.The radii extracted from the approximation(the slopes of the?tted lines in the ln(I(Q)?Q)vs.Q2plot)for the b0and b00precipitates,ensuring the increasing trend of the radii with aging time,are consistent with those obtained from the model?tting of Eq.(3).Note that the observed in situ SAXS pro?les with a crossover at$0.04A?à1also show the di?erent temporal behaviors of the integrated intensities corresponding to the volume fractions of b0and b00precipitates.For example,the SAXS pro?les in the b00 regime,0.046Q60.1A?à1,show decreasing integrated intensities as the aging time increases,implying the dissolu-tion of the b00precipitates.In contrast,the concurrent b0pre-cipitates still shows a typical precipitation behavior from the time evolution of the integrated intensities in the b0regime. Obviously,the concurrent phase transformations of b00and b0precipitates entered the di?erent stages.

Furthermore,Fig.3(c)shows the selected SAXS pro?les collected during a long aging time ranging from210to

Table2

Radii and relative volume fractions of b00and b0precipitates determined by the model?tting of SAXS data of the AA6022alloy obtained selectively during isothermal aging at260°C

Aging time(min)b00phase b0phase

R(nm)Relative

volume

fraction R0(nm)Relative

volume

fraction

211–235°C a 3.1±32%0.14±61%

235–260°C a 3.1±10%0.80±13%9.0±5%0.08±18% 30 3.1±2% 1.00±2%9.1±1%0.44±3% 90 3.2±2%0.83±2%9.5±1%0.77±3% 150 3.4±2%0.82±2%10.1±1%0.83±3% 210 3.5±2%0.79±2%10.5±2% 1.00±5% 360 3.5±2%0.73±3%10.5±2% 1.00±5% 510 3.4±2%0.65±3%10.5±2% 1.00±5% a During continuous heating from RT to260°

C.Fig. https://www.wendangku.net/doc/9716792791.html,parison of the temporal evolutions of relative volume fractions of b00and b0precipitates obtained from the SAXS model?tting and TEM observations[17]during continuous heating for AA6022alloy. (The volume fraction for each phase is normalized by the maximum value during continuous heating and isothermal aging.)

C.-S.Tsao et al./Acta Materialia54(2006)4621–46314625

720min.The temporal evolution of the SAXS pro?les in the b 0regime shows a time-independent behavior,while that of the SAXS pro?les in the b 00regime shows only a slight reduction of the integrated intensities.The corre-sponding structural parameters,the best-?t values of radii and relative volume fraction of b 0and b 00precipitates by the use of model ?tting of Eq.(3)are listed in Table 2.The TEM observation for this SAXS specimen aged at 260°C (Fig.4)shows that the needle-like b 00precipitates coexist with the rod-like b 0precipitates with a similar length (P 200nm).Both can be easily identi?ed due to the large di?erence in radius.The observed TEM result is,in general,close to the SAXS analysis result ($3nm for b 00precipitate radius and $10nm for b 0precipitates radius).We summa-rize the time-dependent radii and relative volume fractions of the b 00and b 0precipitates during the whole isothermal aging process at 260°C in Figs.5(a)and (b).A TEM result [18]is also shown in Fig.5(b)for comparison.(Note that all types of b 0precipitates,including b 0,b 0A and b 0B ,are treated as the same precipitates in this study.)

Precipitation involves three major coupled processes:nucleation,growth and coarsening.The ?rst two processes are driven by the free energy change of a system during phase separation,and will be completed when the equilib-rium volume fraction of precipitates is reached.In contrast,the coarsening stage (or Ostwald ripening)is driven only by a reduction of interface energy,and is usually considered as the last stage of precipitation,featured with a ?xed equilib-rium volume fraction of precipitates.According to the numerical simulation [30,31]of classic theory,when the system enters a coarsening stage,the growth of the volume fraction of precipitates will saturate asymptotically.The growth rate of precipitates decreases gradually from a power law behavior μt 1/2(typical growth regime)to μt

1/6

Fig.3.(a)Selected time-dependent and cluster-subtracted SAXS pro?les (double-log scale)that show the structural evolution of precipitates in the AA 6022alloy aged at 260°C for 210min.The SAXS pro?les are ?tted (solid lines)using the model of Eq.(3).(b)The selected SAXS pro?les are ?tted (solid lines)in the low-Q region and the intermediate-to high-Q region (inset),respectively,using the Kratky–Porod approximation (linear plot)for the temporal evolutions of the radii of the b 0and b 00precipitates.(c)The cluster-subtracted SAXS pro?les (double-log scale)selected for the temporal evolution of precipitates during a long aging period at 260°C.

4626 C.-S.Tsao et al./Acta Materialia 54(2006)4621–4631

when entering the early stage of the coarsening regime (or transition regime)[27].The transition behavior approaches asymptotically a saturation state [28,31].Nevertheless,in the late stage of the coarsening regime (LSW coarsening [27]),the growth rate speeds up again with a power law behavior of μt 1/3.From the beginning of the isothermal aging shown in Fig.5,the rapidly growing radius and vol-ume fraction of b 0precipitates with aging time still exhibit typical nucleation and growth behavior.After t =210min,the radius and volume fraction evolutions of b 0precipitates with aging time change to typical behavior of early-stage coarsening.It can be deduced that this coarsening stage of b 0precipitates is developed mainly by the length growth.The volume fraction of the b 00precipitates remains in the

nucleation and growth step during continuous heating,and reaches a peak value 30min after isothermal aging at 260°C.Thereafter,the volume fraction of b 00precipitates starts to decrease signi?cantly with the aging time,and at t =510min,saturates at a value of 65%of the maximum volume fraction.

Our SAXS results reveal that 35%of the b 00phase can be consumed by dissolution and/or transformation (b 00!b 0precipitates)within 8h of isothermal aging,and then remain at a constant volume fraction.In contrast,the TEM result [18]in Fig.5(b)shows that the b 00phase decays rapidly and vanishes totally to zero.The SAXS results also show the slight growing radius of b 00precipitates with aging time during 30–https://www.wendangku.net/doc/9716792791.html,pared to the constant radius during continuous heating,the growing radius might illus-trate a feature of the coarsening regime.The saturation of growing radius at t =210min can be explained by the fact that the size increase in the coarsening regime is continued by the length increase of b 00precipitates with an inert radius.

An interesting issue is how the b 00phase transforms into the b 0phase.A previous TEM study [16]proposed that the b 00phase could transform into the metastable b 0A and b 0B phases from the viewpoint of the atomic composition of precipitates.Our in situ SAXS study (see Fig.5(b))demon-strates the rapid nucleation and growth of b 0phase is con-current with the signi?cant dissolution of b 00phase during t =30–210min.In principle,the sites of dissolved b 00pre-cipitates are also more favored as the nucleation sites of b 0precipitates.We do not support the proposition that the metastable phases of b 0series are transformed directly from the b 00phase because the growth and formation of the b 00and b 0precipitates are characterized by the indepen-dent nucleation,growth and coarsening

processes.

Fig.4.Bright-?eld TEM micrograph of AA 6022alloy aged at 260°C for 720min.The widths of needle-like (indicated by the arrows in the lower left part)and rod-like morphologies represent the diameters of the b 00and b 0precipitates oriented along ?010?Al

directions.

Fig.5.(a)Temporal evolutions of the radii of the b 00and b 0precipitates extracted by the model ?tting of the SAXS data of the AA 6022alloy aged at 260°C.(b)Comparison of the temporal evolutions of relative volume fractions of the precipitates obtained by the same SAXS analysis (b 00phase:open square;b 0phase:open circle)and TEM result [18](b 00phase:?lled square;b 0phase:cross).

C.-S.Tsao et al./Acta Materialia 54(2006)4621–46314627

The limitation determining particle size depends mainly on the Q range of a measured scattering pro?le.As a rule of thumb of QR61.0,we measured the scattering pro?le in the Q range covering Q=1/R for determining particles with a radius R.The Q range used in this study,0.01–0.1A?à1,corresponds to an observable size scale from the order of10nm to the order of1nm for spherical clusters or needles.According to this principle,the Q range covered by the SAXS data(0.01–0.1A?à1)in this study cannot resolve unequivocally sizes larger than$31nm(p/Q min), according to the model-independent Kratky–Porod approximation.Nevertheless,with model-dependent?t-ting,we may extrapolate a length scale of150–1nm or less, with a larger uncertainty in the?tted length.

With rigorous SAXS analysis,one can determine the absolute volume fraction of nanoparticles in bulk materi-als,including alloy precipitates,as already demonstrated in many SAXS applications[20–23].Unfortunately, because of interference by the preexisting natural clusters and the complex crystal structures in our case,we have dif-?culty in correlating the relative to the absolute volume fraction of the precipitates.

https://www.wendangku.net/doc/9716792791.html,parison of precipitation behaviors of b00phases in di?erent Al–Mg–Si alloys aged at180°C

The in situ SAXS and TEM results presented here yield the temporal evolution of the nanoprecipitate structure in AA6111alloy aged at180°C(only b00precipitation occurs at this temperature),in terms of radius,length and volume fraction.The SAXS analytical method and results for AA 6022alloy aged at180°C are reported in detail elsewhere [25].This section compares the precipitation kinetics and behavior of b00precipitates in AA6111and AA6022alloys, taking into account the e?ects of Mg and Si contents.

Fig.6(a)presents selectively the time-dependent SAXS pro?les obtained from both Al–Mg–Si alloys during heat-ing from RT to180°C and during subsequent arti?cial aging at180°C.The standard deviation of the SAXS pro-?les presented in Fig.6(a)is within±2%except for that of AA6022at RT.As mentioned previously,the power law scattering of Qà4in the low-Q region corresponds to the asymptotic scattering behavior of other large particles. The SAXS pro?les in the intermediate-Q region measured at RT and during isothermal aging at180°C are attributed to scatterings from the natural aging clusters and b00precip-itates,respectively.According to Fig.6(a),the SAXS inten-sity in the intermediate-Q region of the AA6111alloy at RT considerably exceeds that of the AA6022alloy,dem-onstrating that AA6111has more natural aging clusters formed at RT.Our rough comparison of TEM observa-tions between AA6022and AA6111alloy samples natu-rally aged at RT(not shown here)also con?rms this SAXS measurement.Because the composition of the natu-ral aging cluster is similar to that of the b00precipitate(Mg/ Si ratio is1)[2,9],AA6111alloy with a higher MgSi con-tent produces more clusters.The SAXS pro?les measured during the heating process and the SAXS pro?le of the alloy isothermally aged at180°C for60min(not shown here)are nearly the same,indicating that the incubation period is$60min(during which no structural change occurs).The incubation period of AA6111alloy exceeds that,$30min,of the AA6022alloy[25],because the e?ect of more natural aging clusters greatly reduces the quench-in vacancies at RT,and thus the di?usion rate of solute atoms.The similar incubation behavior in the pre-aged Al–Mg–Si alloys was also validated independently by a recent thermal analysis[33].

After60min of aging,the intensity of the SAXS pro?les in Fig.6(a)increases with the aging time in the intermedi-ate-Q region(Q P0.03A?à1),indicating increases in the size and volume fraction of b00precipitates.The coexistence of hard-dissolved natural aging clusters and precipitates during precipitation from the SAXS pro?les measured dur-ing isothermal aging at180°C can be expressed as

IeQT?I precipeQTtaáI clustereQ;t0TtBe4Twhere the time-dependent I precip(Q)is the scattering contri-bution of the precipitates.a is the percentage of the surviv-ing or non-dissolved clusters during arti?cial aging.

I cluster(Q,t0)represents the SAXS pro?le measured at RT corresponding to the scattering contribution of all initial clusters.B is a constant incoherent background.The SAXS intensity of the precipitates of the arti?cially aged alloy is modeled as

I precipeQT?AQà4tgeD qT2V P~PeQTe5Twhere the?rst term refers mainly to the lowest-Q region, with A being a constant,describing the sharp boundary e?ect of large particles.The second term is the cylindrical form factor that relates to scattering from the b00 precipitates.

The SAXS background pro?le,I cluster(Q,t0)in Eq.(4), can be regarded as a sum of C?Qà4(C is a constant)for the large particles and the intensity scattered from the small natural aging clusters(GP zones).Note that I precip(Q)and I cluster(Q,t0)include the Qà4power law scattering terms. The volume fraction of large particles can be assumed not to change throughout natural aging or arti?cial aging, so the relationship A+a?C=C can be deduced by substituting Eq.(5)into Eq.(4).This relationship con-straints the e?ect of large particles and is maintained dur-ing the model?tting using Eqs.(4)and(5).With the measured I cluster(Q,t0),the structural parameters g(D q)2, R,L,a,A and C are thus extracted by the model?tting, as summarized in Table3.The SAXS pro?les from which the cluster contribution is subtracted using a?I cluster(Q,t0), i.e.,I precip(Q),are?tted well using Eq.(5)(Fig.6(b)dis-plays the selected?tting curves).The model-?tted radii, indicating time-independent behavior,are consistent with those obtained by the model-independent method (Kratky–Porod approximation)and the TEM observation shown in Figs.6(c)and7,respectively.The mean radius of b00precipitates,1.78nm,determined by model?tting for

4628 C.-S.Tsao et al./Acta Materialia54(2006)4621–4631

the AA 6111alloy is smaller than that for the AA 6022alloy,2.77nm.This di?erence between the radii is also demonstrated by comparing the slopes of the lines ?tted using Kratky–Porod approximations with the SAXS data obtained for both alloys (Fig.6(c)).The smaller radius for the AA 6111alloy can be attributed to the reduced sol-ute atoms due to more natural aging clusters formed.The model-?tted lengths for the AA 6111alloy are similar to those for the AA 6022alloy.

For the isothermal aging of naturally aged alloys,the DSC result shows only characteristics of the b 00precipita-tion during 180°C aging,and there is no sign of GP peak [1].In the current study,the GP zones are the natural aging clusters serving as the b 00nucleation sites.In principle,it will be increasingly di?cult to separate the SAXS contribu-tions from two coexistent phases (for instance,GP-zones and b 00phase)in a system using the method developed in this study,when the characteristic sizes of the two phases become increasingly close.

The existence of Cu in the clusters can increase in prin-ciple the scattering contrast between the precipitates and the Al matrix,and thus enhance the SAXS intensity observed for the AA 6111alloy,compared to that for the AA 6022alloy.In the current study,we could not evaluate quantitatively the scattering contrast e?ect due to the Cu content.Therefore,we use the SAXS intensity at RT as a part background subtraction and adopt separately a relative volume fraction expression in the data

analysis.

Fig.6.(a)Selected time-dependent SAXS pro?les (log-to-linear plot)of the naturally aged AA 6022and AA 6111alloys during heating and subsequent isothermal arti?cial aging at 180°C,revealing the structural evolution of precipitates with aging time.(b)Cluster-subtracted SAXS pro?les (double-log plot)with a best-?t a of 0.5.Calculated SAXS pro?les (solid lines)simulate well the measured SAXS data,I precip (Q ).(c)The selected SAXS pro?les of the AA6111alloy are ?tted (solid lines)using the Kratky–Porod approximation for the temporal evolution of the radius of the precipitates.The SAXS pro?le of AA 6022alloy is ?tted (dash line),indicating a larger radius (slope of ?tted line).

C.-S.Tsao et al./Acta Materialia 54(2006)4621–46314629

However,the SAXS pro?les of AA 6111alloy aged for 400min match closely those of AA 6022alloy aged for 430min,as shown in Fig.6(a).This result indicates that in this aging range,e?ect of Cu-containing precipitates (Q 0or b 00phases)in AA 6111alloy does not obviously in?uence the scattering contrast of the precipitates.

Because the AA 6111alloy is an Al–Mg–Si alloy contain-ing Cu,another type of precipitate with a higher Cu con-tent,called Q 0phase,coexists with the b 00precipitates during aging at 180°C.The previous TEM studies [5,6]showed that Q 0phase is lath-like (or plate-shaped)and is similar in cross-section to b 00phase.Accordingly,the main e?ect of Q 0phase on the SAXS pro?les is to change the scat-tering contrast.A typical TEM observation [5]of the AA 6111alloy aged at 180°C for 11h shows the needle-like

b 00phase of 3.0·3.0nm in cross-section and 20nm long,and the lath-like Q 0phase of $2.0·5.0nm in cross-section and $100nm in length.Fig.7shows our TEM observation of the b 00phase and the coexisting Q 0phase,which is consis-tent in morphology with the TEM result discussed above.Previous work [6]pointed out that within $7h of aging at 180°C,the volume fraction of b 00precipitates is 2–4times that of the Q 0phase.In contrast,the Q 0phase is the major phase for the AA 6111alloy aged at T P 250°C or over-aged at 180°C.Our TEM observation (Fig.7)also con?rms that b 00phase is the dominant one and few Q 0precipitates coexist (shown by the arrows).Additionally,the SAXS pro-?les agree with the prediction for the length of b 00needles,indicating the amount of Q 0phase is small.

Based on the characteristics of similar cross-section,the present study considers the minor Q 0phase to be in the same category as the b 00phase.Thus,the b 00radius deter-mined from the SAXS pro?le involves the error source resulting from the Q 0phase.The error source is tolerable in the present aging condition.For the AA 6111alloys aged at T P 250°C or over-aged at 180°C,the error source becomes signi?cant due to the larger size and pre-dominance of Q 0phase.

The scattering contrasts from the b 00precipitates with and without Cu,the Q 0phase and the Q 0precursor con-struct a convoluted contrast based on similar SAXS pro-?les.Thus,the error source of the relative volume fraction determined comes from the variation in the scattering con-trast weighted by various precipitates.The contrast values D q obtained from the SAXS data ?tting of AA 6111alloy remain quite stable during aging at 180°C.Therefore,it can be concluded that precipitates’evolution during aging does not in?uence the convoluted contrast.

Fig.8compares the temporal evolutions of the relative volume fractions of precipitates in both AA 6022and AA 6111alloys obtained by SAXS model ?tting with that for an Al–0.63%Mg–Si alloy obtained by the

numerical

Fig.7.Bright-?eld TEM micrograph ([100]Al zone axis)of AA 6111alloy aged at 180°C for 400min.Most dots display the circular cross-section of needle-like b 00precipitates.Few dots (as indicated by the arrows)show the lath-like cross-section of Q 0phase,which is similar to other TEM observations [5,6].

Table 3

Radii,lengths and relative volume fractions of b 00precipitates determined by the model ?tting of SAXS data of the AA6111alloy during isothermal aging at 180°C Aging time (min)R (nm)L (nm)Relative volume fraction a 120 1.65±9%14.7±9%0.43±15%260 1.90±3%14.9±4%0.74±5%340 1.77±3%15.8±4%0.87±6%400

1.80±2%

16.2±4%

1.00±5%

The absolute and relative volume fractions (b 00+Q 0)obtained from the TEM study [6]for the naturally aged AA 611alloy aged at 180°C:(1)f Abs =2.6·10à3,f Rel =33%for 60min aging;(2)f Abs =7.9·10à3,f Rel =100%for 420min aging.a

The parameter determined by the ?tted g (D q )2value normalized to its

maximum.

https://www.wendangku.net/doc/9716792791.html,parison of temporal evolutions of the relative volume fractions of precipitates determined from the SAXS model-?tting results for both alloys aged at 180°C with that predicted by numerical simulation [28]based on classic theory [27].

4630 C.-S.Tsao et al./Acta Materialia 54(2006)4621–4631

simulation[28]based on the classic model.The numerical simulation was based on arti?cial aging at180°C without natural aging treatment.All temporal evolutions presented in Fig.8are characterized e?ectively by coupled nucle-ation,growth and coarsening.The SAXS results for both alloys clearly indicate the incubation period associated with the natural aging e?ect.The incubation period of AA6111 alloy,$60min,exceeds that of AA6022alloy,$30min, because the former alloy has a higher MgSi content.How-ever,the incubation period does not in?uence the time required for the relative volume fraction to reach one. 4.Conclusions

With the high-?ux SAXS results together with the new SAXS analysis approach,we have established an algorithm to extract the structural evolution of metastable b00and b0 phases of Al–Mg–Si alloys.Justi?ed by the consistent TEM result,this methodology is of potential applicability in a wider context of multi-component age-hardening alloys.The in situ SAXS,TEM and numerical simulation based on the classic theory together can provide an inte-grated understanding of the transformation kinetics of the precipitates.We summarize the precipitation kinetics and concurrent transformation behaviors of the metastable phases observed as follows:

1.For the naturally aged AA6022alloy,the b00and b0

phases begin to form at211and235°C,respectively, during continuous heating.The volume fraction evolu-tions of b00and b0precipitates with aging time during continuous heating and subsequent isothermal aging at 260°C can be well characterized by the typical nucle-ation,growth and coarsening stages.The b00and b0pre-cipitates reach the coarsening stages at t=30and 210min,respectively.Afterwards,the b00precipitates start to dissolved partially and/or transformed partially to b0phase,then saturate with a volume fraction of65% of the maximum value after t=510min.

2.The radius of rod-like b0precipitates increases obviously

from9.1±0.1nm to10.5±0.2nm during the nucle-ation and growth stage,and then remains approximately constant during the coarsening stage(210

18.3nm to a length much larger than100nm during

nucleation and growth stages.In the coarsening stage, the radius of b00precipitates grows slightly from

3.1±0.06nm to3.4±0.07nm during30–210min,then

followed by an increase mainly in the length.The slight radius increase might be related to some b00precipitates serving as b0nucleation sites.

3.For the AA6111alloy aged at180°C up to400min,

with the main precipitates of b00phase,the structural evolution of the precipitates also exhibits a constant

radius of$1.8nm and an increase in length with aging time.The longer incubation period in the early stage of precipitation,compared to the AA6022alloy,is attributed to more natural clusters.No clear e?ect of Cu can be identi?ed in the structural evolution of the precipitates.

References

[1]Miao WF,Laughlin DE.Scripta Mater1999;40:873.

[2]Edwards GA,Stiller K,Dunlop GL,Couper MJ.Acta Mater

1998;46:3893.

[3]Marioara CD,Andersen SJ,Jansen J,Zandbergen HW.Acta Mater

2001;49:321.

[4]Marioara CD,Andersen SJ,Jansen J,Zandbergen HW.Acta Mater

2003;51:789.

[5]Perovic A,Perovic DD,Weatherly GC,Lloyd DJ.Scripta Mater

1999;41:703.

[6]Esmaeili S,Wang X,Lloyd DJ,Poole WJ.Metall Trans A

2003;34:751.

[7]Donnadieu P,Carsughi F,Redja?¨mia A,Diot C,Lapasset GJ.Appl

Crystallogr1998;31:212.

[8]Maruyama N,Uemori R,Hashimoto N,Saga M,Kikuchi M.Scripta

Mater1997;36:89.

[9]Maruyama N,Hono K.Acta Mater1999;47:1537.

[10]Esmaeili S,Lloyd DJ,Poole WJ.Acta Mater2003;51:3467.

[11]Bryant JD.Metall Trans A1999;30:8.

[12]Gupta AK,Lloyd DJ,Court SA.Mater Sci Eng A2001;301:140.

[13]Dumolt SD,Laughlin DE,Williams JC.Scripta Metall1984;18:

1347.

[14]Matsuda K,Tada S,Ikeno S,Sato T,Kamio A.Scripta Metall Mater

1995;32:1175.

[15]Matsuda K,Sakaguchi Y,Miyata Y,Uetani Y,Sato T,Kamio A,

et al.J Mater Sci2000;35:179.

[16]Matsuda K,Ikeno S,Sato T.Science,technology and education of

microscopy:an overview.Formatex Microscopy Book Series,2002.p.

152.

[17]Matsuda K,Ikeno S,Matsui H,Sato T,Terayama K,Uetani Y.

Metall Trans A2005;36:2007.

[18]Matsuda K,Uetani Y,Sato T,Ikeno S.Metall Trans A2001;32:1293.

[19]Massardier V,Epicier T,Merle P.Acta Mater2000;48:2911.

[20]Guinier A,Fournet G.Small angle X-ray scattering.New York

(NY):Wiley;1955.

[21]Glatter O,Kratky O.Small angle X-ray scattering.New York

(NY):Academic Press;1982.

[22]Tsao CS,Chang HL,Jeng US,Lin JM,Lin TL.Polymer

2005;46:8430.

[23]Tsao CS,Chen CY,Huang JY.Phys Rev B2004;70:174104.

[24]Schi?mann R,Haug J,Banhart J.Proceedings of the9th Interna-

tional Conference on Aluminum Alloys,Institute of Materials Engineering Australasia Ltd,2004.p.604.

[25]Tsao CS,Jeng US,Chen CY,Kuo TY.Scripta Mater2005;53:

1241.

[26]Poole WJ,Lloyd DJ,Embury JD.Mater Sci Eng A1997;234–

236:306.

[27]Wagner R,Kampmann R.Materials science and technology:a

comprehensive treatment,vol.5.Weinheim:VCH;1991.p.213.

[28]Myhr OR,Grong?.Acta Mater2000;48:1605.

[29]Myhr OR,Grong?,Andersen SJ.Acta Mater2001;49:65.

[30]Deschamps A,Bre′chet Y.Acta Mater1999;47:293.

[31]Werenskiold JC,Deschamps A,Bre′chet Y.Mater Sci Eng A

2000;293:267.

[32]Glasstone S,Sesonske A.Nuclear reactor engineering.New York

(NY):Van Nostrand Reinhold;1981[Chapter7].

[33]Esmaeili S,Lloyd DJ.Acta Mater2005;53:5257.

C.-S.Tsao et al./Acta Materialia54(2006)4621–46314631

初中班级元旦晚会策划书文档3篇

初中班级元旦晚会策划书文档3篇Junior high school class new year's Day party planning d ocument 编订：JinTai College

初中班级元旦晚会策划书文档3篇小泰温馨提示：策划书是对某个未来的活动或者事件进行策划，是目标规划的文字书及实现目标的指路灯。撰写策划书就是用现有的知识开发想象力，在可以得到的资源的现实中最可能最快的达到目标。本文档根据不同类型策划书的书写内容要求展开，具有实践指导意义。便于学习和使用，本文下载后内容可随意修改调整修改及打印。本文简要目录如下：【下载该文档后使用Word打开，按住键盘Ctrl键且鼠标单击目录内容即可跳转到对应篇章】 1、篇章1：初中班级元旦晚会策划书文档 2、篇章2：班级元旦晚会策划书文档 3、篇章3：班级元旦晚会策划书文档篇章1:初中班级元旦晚会策划书文档第一部分晚会概况【班会组织能力】 1041班是一支有着极强凝聚力的队伍。组织机构健全，工作能力突出。回首往昔，我们已经成功举办了许多次精彩的主题班会，受到同学们的好评。我们将在工作中充分发挥团

队优势，团结合作、共同努力，本着全心全意，全新改版，互惠互利的原则竭诚为您服务!班级元旦晚会策划书我们带着青春蓬勃的朝气和远大的志向来到1041班这个团结友爱的大家庭。我们筹备组打算通过举办迎新文艺晚会，师生共聚一堂，表达对同学们的关心与期望，让我们能更多地了解1041班的优秀文化，使我们能尽快地在高中生活当中找到自己的位置以进入角色。同时，我们通过这个文艺晚会发掘我们1041班的文艺人才，使他们的特长能得到更好的培养，还借它丰富大家的课余生活，提供一个展现个人魅力的舞台。【班会主题】这台文艺晚会的主题是“这个冬天不再冷”。我们需要得到各方面的关心和指导。有老师对学生互动的。所以这次晚会突出一个“爱”字，借联谊班会把大家的感情和祝愿表达出来，让他们能愉快的开始高中三年的学习和生活。【班会形式及内容】整个班会节目诸多，形式不限，内容尽量贴近高中生活贴近主题。具体的节目编排由班会筹备组负责和组织。所有节目需提前准备，经过节目策划组审查之后，合格的节目方可在

六年级元旦联欢会作文500字【五篇】

六年级元旦联欢会作文500字【五篇】【篇一】六年级元旦联欢会作文500字在一个阳光明媚的早上，我怀着无比激动的心情，像小鸟一样飞向学校，因为今天是一个特别的日子——20xx年元旦节。清晨的马路上已是车水马龙，小朋友的脸上洋溢着节日的.欢乐；街道两旁的商店装饰得漂漂亮亮，一棵棵圣诞树随风摇曳，一个个圣诞老人在不停的向来往行人招手。刚一踏进学校大门，节日喜气洋洋的气息马上扑面而来。各个教室在同学们的小手装扮下，充满了节日的气氛。小朋友个个身着节日盛装，高兴的跑着笑着。 9点整，一个庄严的入队仪式在雄壮的音乐中拉开了序幕，一个个小朋友在鲜艳的对旗下高高的举起他们幼嫩的小手，此时此刻他们成了一名光荣的少先队员。升旗仪式结束后，同学们各回各班，元旦联欢会正式拉开了序幕。同学们个个兴高采烈，跃跃欲试，我也无比激动，因为很快该我表演了。在一阵阵热烈的掌声中，被同学们封为“古筝大师”的我，羞答答走到主席台。我信心十足的弹了起来，可刚一抬手，衣服扣子就挂到了古筝弦，真倒霉，码子也掉了一个。还好有老师在，张老师迅速帮我修好琴。我索性脱掉棉袄，“赤膊上阵”。 “大师”绝非浪得虚名，刚弹两句，已是掌声四起。我越弹越来劲，台下的掌声也越来越激烈。我的心里别提有多美了。

事情已经过去了很久，但我仍久久难忘，它使我明白了一个道理：我们的掌声是对别人的鼓励。【篇二】六年级元旦联欢会作文500字随着时光老人的脚步，我们迎来了新的一年——xxxx 年。在20xx年的前一天下午，我们班成功的举行了一场联欢会。中午，李晗雪等同学把我们班打扮地漂漂亮亮的，在黑板上写下了：庆元旦联欢会，着几个大字，还画上了一些气球、花等多种装饰还在教师的门上、窗上粘上了气球。在电风扇上挂起了五颜六色的彩带。如果你猛地走进教室，你一定有一种耳目一新的感觉。下午，同学们来了，并坐倒了自己的位置上，观看表演。过了一会，联欢会开始了。先是主持人发言，发言完毕后，联欢会正式开始了。有弹吉他的，有拉大提琴和拉小提琴的，有说相声的，以打快板的，有唱歌的，真是应有尽有。但令我印象最深刻的还是弹琵琶着项节目。下面，由彭月欣为大家演奏琵琶。彭月欣迈着步子走到了教室中间，并坐了下来静静的弹，当她弹到令一首曲子时，哪声音好像百鸟争鸣，哪曲子真是清脆动听。她弹的时候仿佛融入到了里面。她的曲子弹的既流畅又优美，我的身心都陶醉其中了。不一会，彭月欣的演奏完毕了。啊！听这一首歌，我的脑海中的烦事、愁事，都抛到九霄云外了，听着一首曲子，我仿佛获得了无数精神上的粮食，真是百听不厌。我们班梅表演完一个节目，

医学院十二五规划

湖州师范学院医学院“十二五”发展规划（征求意见稿）学校“十二五”规划提出到2015年把学校建设成为省内外有影响力的特色大学，整体办学水平处在全省同类院校前列，努力实现办学层次、特色构建、条件建设、服务能力和综合实力新突破的总体目标。在学校全面深化特色大学建设进程中，医学院紧紧围绕提高办学水平、增强综合实力、提升人才培养质量，为加快学校建设特色大学的目标，特制定医学院“十二五”发展规划。一、学院的发展现状（一）发展基础 “十一五”时期，是学校改革发展取得重大进展的五年。五年来，学院根据学校建设综合性本科院校的定位与规划，充分利用学校的综合资源优势，加强建设，学院的办学条件与办学水平有了显著的提高。办学规模不断扩大。医学院现有临床医学、口腔医学、护理学三个本科专业和临床医学（定向农村社区医学）专科专业，在校生1900余名。师资队伍素质提高。现有专任教师57人，其中正高职称11人，副高职称13人，具有硕博士研究生学位教师38人，占专任教师总数的67%，其中博士生9名。另有附属医院临床教师115人。学科和科研建设成果显著。护理学成为省级重点建设专业、校级重点建设学科，是省级护理人才培养模式创新实验区；口腔医学的口腔修复学科是市级临床医学重点学科；临床医学专业在全省率先开展面向农村社区培养临床医学人才，并被确立为全省三个培养基地之一。有省级精品课程2门、校级精品课程5门。获得市厅级以上课题32项，其中国家自然科学基金3项，省部级项目6项。全国教育科学规划课题-教育部重点课题1项，省新世纪教改课题4项。获得省教学成果二等奖1项，校级教学成果一等奖3项。教学条件建设得到改善。实验仪器设备总资产约1200万元，形成了基础医学实验教学中心、临床与护理技能实验教学中心和口腔医学实验教学中心并立的

中学生班级元旦晚会策划方案

中学生班级元旦晚会策划方案本次晚会也将是本学期最后一次晚会，会前是圣诞节，会后是元旦节。我们在此相遇的第一学期里，希望通过丰富、生动的表演为大家今后的精彩的大学生活埋下伏笔，创造更有意义更能让人们珍惜的精彩时刻。为了庆祝元旦为此班级举办元旦晚会，为本次晚会制定策划书，*是中学生班级元旦晚会策划方案，仅供参考。中学生班级元旦晚会策划方案1 既本学期各种班级活动开展以来，一直都以有为大学，励志青春为主题。从中也深刻了解到班委以及班级成员之间的优势和所存在的矛盾。总的来包括为以下几点。一、班委之间合作意识不够到位，工作态度、责任意识并不具备一个优秀班委会的要求。应当继续的强调并带头发展下去，登上更高的层次。二、班级中部分成员的价值观和生活学习等部分方面需要我们班级各个成员继续予以正确导向。向着更加高效、更加有利、更加科学方面不断进步。其次，就本次即将开展的元旦晚会做以下策划。针对将来各位同学的工作仕途，能培养各方面能力以争取更广面的优秀，我建议：一，本次晚会以正规出演方式进行。二：本次晚会要具有

教导意义。三、本次晚会在有限的时间内深入大学生所面临的诸多领域。下来就本次班会的具体部署情况出示如下：班会主题： 10级防雷5班圣诞元旦联欢晚会班会时间： 20.12.28日晚5:30分整(后勤人员于5:00布置会场) 班会背景： 1. 现在就读大一，距离大三毕业只能继续开办一次圣诞元旦联欢晚会，大家或许会在将来的工作岗位上承担晚会策划项目，就必须从现在开始积极接触正规晚会的策划流程，这样才能在未来更加出众。 2. 本次班会正好是在全国上下开办“创优争先”党建活动期间，所以我们的班会内容也要在不同程度上靠拢这方面话题。我们将继续发扬党政文化，科学发展观念，健康心理等方面，这样也就给本次晚会的开展带来挑战。所以，我们务必具有自己的特色，自己的亮点。 3. 本次晚会也将是本学期最后一次晚会，会前是圣诞节，会后是元旦节。我们在此相遇的第一学期里，希望通过丰富、生

班级难忘的元旦联欢会作文

班级难忘的元旦联欢会作文班级难忘的元旦联欢会作文1 今天我们班举行了一场元旦联欢会。午休时家长们纷纷来到教室装扮联欢会场地，同学们也不甘落后，都来帮着吹气球。眼看就要上课了，同学们排着整齐的队伍去音乐教室上音乐课。等我们回来时，都惊呆了，教室里张灯结彩，喜气洋洋，课桌都摆在教室左右两旁。我们井然有序地坐在教室后面。看着课桌上摆放着的各种各样的小零食，有些同学口水都流出来了。教室中间就是我们的舞台。待大家安静下来时，节目也就开始了，第一个节目是吴思悦和司冉二位同学合唱的《虫儿飞》，可能是她们第一次上台表演的缘故，唱的声音有点小，但很动听，同学们都向前倾着身子，静静地听着歌声。表演完毕，教室里响起了欢快的掌声。开始分零食了，同学们嘻笑着一拥而上，有的同学甚至说：“哈哈，我的馋嘴巴快等不及了！”平时不怎么积极的我，也使出了吃奶的力气跟同学们挤在一起！第五个节目是我和宋鑫鑫二人表演的“斗牛舞”，开始时我俩都很紧张，担心跳不好，会被同学们笑话，当我们跳完一曲后，从教室里响起经久不息的掌声来看，我们的担心是有点多余了，连刘同学都对我们刮目相看，但我还是有些害羞！

时间一分一秒地过去了，联欢会结束了，大家恋恋不舍地走出了教室。走时，我暗暗下了决心，明年要准备更好的节目来表演！班级难忘的元旦联欢会作文2 上个星期天的上午，我们快乐作文班举行了一场令人难忘的元旦联欢会。走进教室，只见里面热闹非凡。洁白的天花板上挂着许许多多、五颜六色的气球，椅子白城了u字形，而同学们呢？有的开怀大笑，有的窃窃私语，有的兴奋不已，还有的…… 几分钟后，元旦联欢会开始了，有好多新奇有趣的游戏，但给我印象最深的还是踩气球了。首先，一位主持人走上讲台，微笑着给我们讲了规则。接着，我们这几个被幸运点到的同学在左腿上绑好三个气球，游戏开始了！我的对手是一个女生，我一个劲儿往前冲，她左躲右闪，可哪里躲得过去？“啪”的一声，她的气球被我踩爆了一个，她见损失了一个气球，便急忙跑开，我见了，心想：哦？三十六计，走为上策！我追！他见我马上就追了上来，只好转过身，跟我硬碰硬。她四处乱

卫生部十二五规划纲要全文

以下是卫生部明确提出来的“十二五”卫生发展总体目标，这目标的实现意味着未来五年国家还需投入最少数千亿元来实现自己对于民生的承诺，这个目标不是靠药品降价能实现的，反过来说药品降价仅仅是这个大棋局中的很小一个方面，资本市场对其的担忧过虑了。 “人均期望寿命达到74.5岁，婴儿死亡率和5岁以下儿童死亡率分别降低至12％和14％，孕产妇死亡率降至22/10万，个人卫生支出比例降至30%以下。”在1月6日召开的2011年全国卫生工作会议上，卫生部部长陈竺在提出“十二五”卫生发展目标时，用了这一组数字进行了具体的描绘。卫生部明确“十二五”卫生发展的总体目标是，到2015年，覆盖城乡居民的基本医疗卫生制度初步建立，基本医疗保障制度更加健全，公共卫生服务体系和医疗服务体系更加完善，药品供应保障体系更加规范，医疗卫生机构管理体制和运行机制更加科学，基本医疗卫生服务可及性显著增强，居民个人就医费用负担明显减轻，人民群众健康水平进一步提高。地区间资源配置和人群健康状况差异明显缩小，国民健康水平达到发展中国家前列。人均期望寿命达到74.5岁，婴儿死亡率和5岁以下儿童死亡率分别降低至12％和14％，孕产妇死亡率降至22/10万，个人卫生支出比例降至30%以下。 “十二五”期间，我国卫生发展的主要任务有以下四个方面：加强医疗卫生机构能力建设，提高医疗卫生服务水平强化区域卫生规划和医疗机构设置规划，明确各类医疗卫生机构的功能和职责，优化规模、结构和布局，形成防治结合、中西医并重、功能互补、信息互通、上下互动的医疗卫生服务体系。

加强公共卫生服务体系建设，重点改善疾病预防控制、精神卫生、妇幼卫生、卫生监督、卫生应急、职业病防治、采供血、健康教育等专业公共卫生机构的设施条件。继续加强农村急救体系、乡镇卫生院和村卫生室标准化建设，为中西部地区乡镇卫生院职工建设周转房；全面推进县级医院标准化建设，使其总体达到二级甲等水平；整合县域医疗卫生资源，推进综合改革，转变运行机制，完善绩效工资，实现服务功能和模式转变。积极稳妥推进公立医院改革，完善公立医院服务体系，改革管理体制、治理机制、运行机制和补偿机制，加强医疗安全质量监管，促进科学化、精细化、专业化管理，改善服务，提高效率。初步建立国家医学中心体系，加强区域医疗中心和临床重点专科建设；继续加强社区卫生服务机构建设，力争每个街道办事处范围设置一所政府办的社区卫生服务中心，形成以社区卫生服务为基础、社区卫生服务机构与医院和专业公共卫生机构分工合理、协作密切的新型城市卫生服务体系。继承创新中医药，建立比较完善的中医医疗预防保健服务体系、科研创新体系，加强中医药队伍建设，发挥传统医学在保护国民健康中的作用。加快卫生法制建设，实施医疗卫生人才培养基地建设和医药卫生信息化建设，为卫生改革发展提供有力支撑。鼓励支持社会资本举办非营利性和营利性医疗机构，积极参与健康管理、老年护理、口腔保健和康复健身等健康服务业的发展，形成多元化办医格局，满足多样化、多层次医疗、预防、保健、养老、康复服务需求。健全医疗保障制度，提高疾病经济风险分担能力

班级元旦晚会节目

班级元旦晚会节目篇一：2015年元旦文艺汇演各班节目名单 2015年元旦文艺汇演各班节目名单篇二：适合班级元旦晚会玩的小游戏集锦适合班级元旦晚会玩的小游戏集锦快元旦了，每个同学班级都要举办元旦晚会。元旦晚会除了大家表演一些节目外，大家一起做一些好玩的小游戏也是很好的选择，当然节目和游戏可以穿插进行，为了方便同学们更好的举办一场成功的元旦晚会，我总结整理了上学时组织节目时经常玩的几个非常有意思的小游戏，供大家参考。 “过、七”游戏成员围成一个大圆圈，由任意一人开始从1报数，旁边的人依次报2、3、4??在报数的过程中，凡是报到7和7的倍数还有带7的数时，不能喊数，要喊“过！”，犯规的人将受到处罚，处罚方式，男生做五个俯卧升，女生要手背后边做五个起蹲。水杯游戏用一个直径大约15厘米的玻璃杯（最好），不过如果人多的话可以用直径大一些的杯子，然后把杯子装满水，注意是几乎装满，离杯口差一到两毫米，然后每个人轮流方一粒石头入水，然后看谁放进去的时候水溢出来了,输的人罚水一杯千里传音分成两组，单列站好，成员每人口里含一口水，主持人用小纸片写一句话，然后由第一个人依次往后传递，传递到最后一个人时把这句话给说出来。 007游戏游戏环节：十个人左右围成圆圈，先任选一总统，快速在圈中成员用食指任意指定一人为007，指定为007的人马上伸出右手并做手枪状朝圆圈中任意一人开枪，开枪时要大声喊出“啪！”，然后中枪的人不能动也不能发出任何声响，但是两边的间谍要马上举起双手做出中枪状，并大声喊“啊！”，犯规的人要受到处罚，受到处罚后，在下次游戏中当总统来指定007，接下来依次类推。游戏规则：游戏过程中无关的人身子都不能动，也不能喊出“啪！”或者“啊！”，但是可以笑，犯规的人将会受到处罚处罚规则：犯规的人站在圆圈中间用屁股把自己的名字写出来 “天地花开” 场地中放置汽球若干（红、黄、蓝数量均等），天花板悬挂18个大汽球（红、蓝、黄各六个），每组抽三人参加比赛，红队踩红色的汽球，黄队踩黄色的汽球，蓝队踩蓝色的汽球，踩完地上所有的汽球后，谁先用头扎完天花板上自己队的汽球为胜。（每个队员戴可扎破汽球的发夹一个）（9人）（三队同时进行）－－汽球内装入彩屑若干，现场效果十分出抛绣球 {准备：提供3个小筐（小筐包装的漂亮一点），40个气球} 游戏规则：一局六名选手，两人一组，一人背筐，一人投球。背筐者努力接住来自投手的球，最后以接球的多少决定最后的胜负。此游戏主要考察两人的配合能力，看谁最后满载而归。两人一组，一人背筐，一人投球。背筐者想尽办法接住球。接球多的一组获胜。共

国家十二五规划全文

中国“十二五”规划研究新的起点上，人们往往是在忙着想两件事情，一件是回首，一件是展望，站在“十二五”规划的浪口，我们深知“十二五”规划更具全局性和战略性。房产、汽车、清洁能源、低碳经济、民生、就业、医疗改革、社会和谐……等等问题与建议在“两会”时期已被提上，“五年计划”是中国国民经济计划的一部分，是对中国经济的发展确定航行目标与方向做充足的预言，如何把脉中国未来五年中国经济发展走向、如何更快更好促进中国社会发展，五年发展规划责任重大、意义重大。为此，北京华经纵横咨询有限公司借国家规划、产业开发这个强势东风，特邀众学者、研究专家成立“十二五”规划课题组，对“十二五”前期重大问题研究做详细客观的评述与综合分析。课题组根据“十一五”规划《纲要》实施情况以及“十二五”发展面临的形势和任务，从重点课题项目的提出、前期调研、论证、筛选以及最终确定都具有一整套严格科学的流程和方法，是深入实践科学发展观、全面落实十七大提出的新的发展要求的五年规划，也是承诺实现联合国千年发展目标的五年规划，对实现全面建设小康社会宏伟目标具有重要意义。在此，本课题成员结合当前“十二五”规划动态，通过整理、筛选、分析和判断整理了当前国家“十二五”规划动向，具有一定的参考价值。

本报告目录：【“十二五”规划概要】 2 【“十二五”规划前期重大问题研究】 2 【“十二五”规划研究重大选题一览】 3 【“十二五”规划前期重大问题研究选题参考】 4 【政府“十二五”规划思路和方法】 6 【中国“十二五”规划谋三大转型】 6 【发改委：“十二五”规划八大重点】 7 【科技部：“十二五”科技规划六大方向】 8 【商务部：“十二五”规划拟把内贸放重要位置】 8 【交通部：“十二五”规划避免“漏一、挂万”倾向】 9 【住建部：“十二五”规划房地产发展仍以居民消费为基础】 9【劳动和社会保障部：“十二五”期间实施调查失业率】 10【农业部：编制948计划的“十二五”规划】 10 【文化部：“十二五”末基本扭转文化产品出口逆差】 11 【卫生部：疾控“十二五”规划坚持以人为本】 12 【电力行业“十二五”规划重点分析】 12 【中国农业发展存在问题及“十二五”规划思路研究】 13 【钢铁工业“十二五”规划发展思路解析】 15 【能源行业“十二五”规划突出六大重点】 16 【对“十二五”房地产业发展规划的五条建议】 17 【“十二五”规划我国装备制造业的指导原则与目标取向】 18【“十二五“规划：助中国汽车业由大到强】 19 【医疗器械产业“十二五”规划突出四方面发展】 20 【煤炭行业“十二五”规划将以减产、整合为主题】 20 【中国通信信息产业“十二五”发展规划预测】 21 【中国人民银行：“十二五”期间着重完善金融体系】 23 【碳排放作为约束性指标纳入“十二五”规划】 23 【北京“十二五”规划将呈现建设世界城市细则】 24 【广东：争取粤港合作纳入“十二五”规划】 25 【上海“十二五”规划以创新推动城市全面转型】 25 【四川“十二五”规划促进高地建设】 26

六年级元旦联欢会作文600字范文

【篇一】六年级元旦联欢会作文600字每当一年一度的元旦节来临时，我们班都会为元旦节开一个联欢会，同学们个个都很开心，所以爽朗的笑声不时地从我们班传出。早晨，一走进教室，就给人一种心旷神怡的感觉。只见教室焕然一新，张灯结彩，呈现出一片喜气洋洋的景象。教室的上方挂着五颜六色的彩带、气球，墙上贴着各种各样的画，窗玻璃上用喷雪喷出了各种图案，漂亮极了。联欢会就在这喜气洋洋的气氛中拉开了序幕。我们一边谈笑一边看节目。首先是扳手腕比赛，上场的是姜汶辰和江宏宇，他们俩可都是我们班的虎将啊！只见他们俩伸出右手，先友好的握了握手，将胳膊肘放在了一张桌子上，虎视眈眈的瞪着对方，好像在说：“我一定要打败你！”双方对视一会后，姜汶辰便沉不住气了，使出了吃奶的力气将江宏宇的手往下扳，脖子上的青筋都要爆了出来，江宏宇也不依他，用力往上反扳。时间在一分一秒的流逝，姜汶辰也一点儿一点儿招架不住了，只听“咚”的一声，姜汶辰输了。然后又是抢椅子游戏。各组派出一名代表，上前去与其他组派出的代表对阵。我很荣幸的代表我们组去参加比赛。随着老师的一声令下，比赛开始了，各位参赛选手围着椅子便转了起来；老师的教鞭一停，我们便争先恐后地坐上椅子。哈哈，我抢到了！耶！就这样，没减下一位选手，就减下一把椅子。最后，就只剩下了一把椅子和两位选手——我和张明聪，在最后一轮中，我成功的打败了张明聪，坐上了最后一把椅子。“耶！”我和小组成员兴奋的击了一个掌。随后我们又开展了许多有趣的游戏，如：贴鼻子、吹气球、击鼓传花……还表演了许多节目，如：表演跳舞、唱歌……表演者们表演的认真、卖力，观众们看得专心，大家都玩得非常开心、尽兴。元旦联欢会结束后，我想：现在得生活水平提高了，人们也注重娱乐了，可能这就是联欢会令人开心的原因吧。【篇二】六年级元旦联欢会作文600字时间匆匆，转眼间，新的一年又来到了，为了庆祝元旦，老师宣布在星期五的下午，将要在本班举行一次联欢会。同学们知道后，一个个摩拳擦掌，准备大显身手。联欢会一开始，大家都八仙过海，各显神通，表演了各种精彩的节目。有让人捧腹大笑的相声，也有让人百思不得其解的魔术，还有悦耳动听的歌曲。同学们的脸上似乎都写着今天的快乐。瞧，我们班的“黄金搭档”又在为我们表演逗人的小品“关于厕所的故事”了。舞台上，

初中班级元旦晚会策划书例文标准版

初中班级元旦晚会策划书例文标准版 Standard edition of planning book for junior high school class n ew year's Day party 汇报人：JinTai College

初中班级元旦晚会策划书例文标准版前言：策划书是对某个未来的活动或者事件进行策划，是目标规划的文字书及实现目标的指路灯。撰写策划书就是用现有的知识开发想象力，在可以得到的资源的现实中最可能最快的达到目标。本文档根据不同类型策划书的书写内容要求展开，具有实践指导意义。便于学习和使用，本文档下载后内容可按需编辑修改及打印。第一部分晚会概况【班会组织能力】 1041班是一支有着极强凝聚力的队伍。组织机构健全，工作能力突出。回首往昔，我们已经成功举办了许多次精彩的主题班会，受到同学们的好评。我们将在工作中充分发挥团队优势，团结合作、共同努力，本着全心全意，全新改版，互惠互利的原则竭诚为您服务!班级元旦晚会策划书我们带着青春蓬勃的朝气和远大的志向来到1041班这个团结友爱的大家庭。我们筹备组打算通过举办迎新文艺晚会，师生共聚一堂，表达对同学们的关心与期望，让我们能更多地了解1041班的优秀文化，使我们能尽快地在高中生活当中找到自己的位置以进入角色。同时，我们通过这个文艺晚会发掘我们1041班的文艺人才，使他们的特长能得到更好的培养，还借它丰富大家的课余生活，提供一个展现个人魅力的舞台。

【班会主题】这台文艺晚会的主题是“这个冬天不再冷”。我们需要得到各方面的关心和指导。有老师对学生互动的。所以这次晚会突出一个“爱”字，借联谊班会把大家的感情和祝愿表达出来，让他们能愉快的开始高中三年的学习和生活。【班会形式及内容】整个班会节目诸多，形式不限，内容尽量贴近高中生活贴近主题。具体的节目编排由班会筹备组负责和组织。所有节目需提前准备，经过节目策划组审查之后，合格的节目方可在这台文艺晚会上表演。节目演出次序由班会主持人和班会策划组决定。班会开始前五至十分钟，开始布置会场并入场。布置与入场期间，班会现场播放音乐和动态宣传的flash。班会进行时，可以使用各种活跃气氛的道具或横幅。整台班会从前至后都要拍摄记录。班会后，凡参加班会与演出的观众和演员都得到筹备组的感谢，并登记名字存档。通过班会嘉宾及观众代表的评选，班会将评选出最具创意节目奖两名，评出最佳表演奖两名，最佳歌手两名，同时通

2020元旦主题活动方案六年级

2020元旦主题活动方案六年级一、活动主题：收获快乐，xx2018 二、活动目的：在新年到来之际，通过丰富多彩的活动，以“收获快乐，祝福2018”为主题，使每一位少先队员都充分享受成长的快乐，体验对他人的感恩之情，感悟做人做事的道理，让每一位少先队员在体验中回味，在快乐中收获，在温情中展望。三、活动时间： 2017年12月31日周一上午9:30-10:30 四、活动地点：六年级各班教室五、参加人员：六年级全体师生六、活动流程： (一)活动准备： 1、师生共同装饰、布置教室(设计板报，摆放桌椅)，体现节日气氛。 2、各班小主持人做好准备。 3、各班巡回文艺表演小演员排练节目。 4、“表彰2017，展望2018”环节奖励品等。 5、制作xx卡片。 (二)活动要求：

(1)本着欢乐、祥和，和谐的理念，一定要保证学生的安全。各班教师一定要提高认识，积极认真准备，展示教师的组织能力。 (2)活动要体现和谐、健康、积极向上的精神风貌，兼顾全体学生。 (3)各班自定节目内容和节目单并拍照保存。 (三)活动过程： 1、欣赏开场舞扇子舞《好日子》 2、欣赏歌舞《英文版最炫民族风》 3、欣赏情景剧 4、欣赏时尚舞 5、六年级各班师生学生互送《2018祝福小卡片》 (四)活动结束：做好各班卫生，关好灯、门窗等，摆好桌椅，关闭多媒体等。六年级组 2017年12月25日一、活动目的： 1、结合“民族精神代代传”活动，号召少先队员广泛传唱革命传统歌曲和爱国歌曲，让队员们在歌声中体验民族精神，增强民族自豪感。 2、通过歌唱形式，陶冶学生情操，丰富学生课余生活，给学生提供展现才华的舞台。 3、通过活动，在全校范围内渲染节日气氛，在活泼、愉悦的氛围中传递新年的祝福和欢乐。

卫生部关于印发《“十二五”时期康复医疗工作指导意见》的通知

卫生部关于印发《“十二五”时期康复医疗工作指导意见》的通知卫医政发〔2012〕13号各省、自治区、直辖市卫生厅局，新疆生产建设兵团卫生局：为贯彻《中共中央国务院关于深化医药卫生体制改革的意见》提出的“注重预防、治疗、康复三者的结合”的原则，满足人民群众日益增长的康复医疗服务需求，全面加强康复医疗服务能力建设，我部根据当前康复医疗工作实际和“十二五”卫生事业发展规划，研究制定了《“十二五”时期康复医疗工作指导意见》。现印发给你们，请遵照执行。二○一二年二月二十九日 “十二五”时期康复医疗工作指导意见康复医疗是医疗服务的重要组成部分，以疾病、损伤导致的躯体功能与结构障碍、个体活动以及参与能力受限的患者为服务对象，以提高伤、病、残人士的生存质量和重返社会为专业特征。疾病早期康复治疗可以避免残疾发生或减轻残疾程度，改善患者生活质量，减轻家庭和社会的经济负担。充分发挥康复医疗机构的作用，有利于提高医疗资源整体利用效率与效益。“十二五”时期是实现全面建设小康社会奋斗目标承上启下的关键时期，也是深化医药卫生体制改革的重要阶段。为适应人民群众不断增长的健康需求以及经济社会发展对康复医学事业发展的新要求，逐步构建完善的医疗服务体系，促进康复医学事业全面、协调、可持续发展，根据《中共中央国务院关于深化医药卫生体制改革的意见》和“十二五”卫生事业发展规划，制定本指导意见。一、指导思想

贯彻落实《中共中央国务院关于深化医药卫生体制改革的意见》，以“注重预防、治疗、康复三者的结合”为指导，以满足人民群众日益增长的康复医疗服务需求为目标，在“十二五”时期全面加强康复医学能力建设，将康复医学发展和康复医疗服务体系建设纳入公立医院改革总体目标，与医疗服务体系建设同步推进、统筹考虑，构建分层级、分阶段的康复医疗服务体系，逐步完善功能，满足人民群众基本康复医疗服务需求，减轻家庭和社会疾病负担，促进社会和谐。二、工作目标（一）提高康复医疗机构建设和管理水平。综合医院康复医学科应达到《综合医院康复医学科基本标准》和《综合医院康复医学科建设与管理指南》（以下简称《标准》和《指南》，下同）要求，康复医院应达到《康复医院基本标准》要求。社区卫生服务中心和乡镇卫生院能够开展基本康复医疗服务和残疾预防、康复相关健康教育。（二）加强康复专业人员队伍建设。逐步建立康复治疗师规范化管理制度，开展在岗康复医师、治疗师和护士培训工作。（三）提高康复医疗服务能力。综合医院康复医学科开展早期、规范化的康复治疗。逐步建立国家级和省级康复医疗质量控制中心并开展质量控制工作。（四）初步建立分层级、分阶段的康复医疗服务体系，逐步实现患者在综合医院与康复医院、基层医疗卫生机构间的分级医疗、双向转诊。（五）统筹规划、合理利用各类康复医疗资源。各级中医医疗机构、妇幼保健机构和残联系统康复机构围绕相关疾病与残疾承担相应医疗与康复工作任务。三、主要任务

初中班级元旦晚会策划书.doc

第一部分晚会概况【班会组织能力】 1041班是一支有着极强凝聚力的队伍。组织机构健全，工作能力突出。回首往昔，我们已经成功举办了许多次精彩的主题班会，受到同学们的好评。我们将在工作中充分发挥团队优势，团结合作、共同努力，本着全心全意，全新改版，互惠互利的原则竭诚为您服务!班级元旦晚会策划书我们带着青春蓬勃的朝气和远大的志向来到1041班这个团结友爱的大家庭。我们筹备组打算通过举办迎新文艺晚会，师生共聚一堂，表达对同学们的关心与期望，让我们能更多地了解1041班的优秀文化，使我们能尽快地在高中生活当中找到自己的位置以进入角色。同时，我们通过这个文艺晚会发掘我们1041班的文艺人才，使他们的特长能得到更好的培养，还借它丰富大家的课余生活，提供一个展现个人魅力的舞台。【班会主题】这台文艺晚会的主题是这个冬天不再冷。我们需要得到各方面的关心和指导。有老师对学生互动的。所以这次晚会突出一个爱字，借联谊班会把大家的感情和祝愿表达出来，让他们能愉快的开始高中三年的学习和生活。【班会形式及内容】整个班会节目诸多，形式不限，内容尽量贴近高中生活贴近主题。

具体的节目编排由班会筹备组负责和组织。所有节目需提前准备，经过节目策划组审查之后，合格的节目方可在这台文艺晚会上表演。节目演出次序由班会主持人和班会策划组决定。班会开始前五至十分钟，开始布置会场并入场。布置与入场期间，班会现场播放音乐和动态宣传的flash。班会进行时，可以使用各种活跃气氛的道具或横幅。整台班会从前至后都要拍摄记录。班会后，凡参加班会与演出的观众和演员都得到筹备组的感谢，并登记名字存档。通过班会嘉宾及观众代表的评选，班会将评选出最具创意节目奖两名，评出最佳表演奖两名，最佳歌手两名，同时通过班会嘉宾抽奖将抽出五位幸运观众。对于质量上乘的作品，可以在以后的主题班会上得到邀请函。【特色节目】 1、由开场节目(或由嘉宾上台致辞)，拉开班会的序幕。 2、情感驿站我们1041班是一支有着极强凝聚力的队伍，是一支怀揣着梦想的队伍。具体形式：可以将梦想写在纸上。大家把心里想说的话写在纸上，并注上自己的名字，然后交给观众席主持人。同时，同学也可以把心里话写给同学。收集完的纸条后，主持人统一把纸条念出来。班会后，我们会把这些纸条保存。 3、《明天会更好》师生同唱【班会地点和时间】

欢乐的元旦联欢会日记_六年级元旦联欢会的日记

欢乐的元旦联欢会日记_六年级元旦联欢会的日记欢乐的元旦联欢会日记篇一 20XX年12月31日，这是20XX年的最后一天了，明天就是20XX年。同学们也在为迎接新年的第一天准备着。俗话说的好：“新年新气象。”第二天，当我迎着新鲜的空气走进校园时，眼前便浮现一片繁忙的情景。有的同学在打扫校园，有的同学在修补这本班的雪雕，总觉得还差那么一点点。有的同学在往树上挂自己手工制作的干枝梅。那一枝枝都那么美丽，那么富有迎接新年的情感。了气球和拉花，让我有一次的感到了新年来临的感觉。结束了。作文欢乐的元旦联欢会日记篇二 !终于，久违的午休铃敲响了，同学们飞快地跑上楼。只见灯管与灯管之间，一条条彩带纵横交错，编织成一个闪闪发光的“彩网”;五颜六色的气球点缀其间，更增添了一种节日的气氛;玻璃窗户上，用喷花写出了四个喜庆的大字：“元旦快乐”;黑板上也用彩色粉笔写了三个漂亮的花体字：“庆元旦”，黑板四周还用彩色气球装饰了一圈。教室里充满了浓浓的节日气氛。联欢会开始了，同学们纷纷拿出自己的拿手好戏，在台上展示着自己的风采。很快就轮到了我的rap表演(说唱表演)：《你好陈水扁》。由于我在第一轮演唱《北极星的眼泪》时发挥失常，于是我决定要在这个节目中一雪前“耻”。“1951年，那是一个春天，台湾的上空，划过一道闪电……”我绘声绘色地表演起来，可同学们似乎对我的表演毫无兴趣，我赶紧加上一些动作，终于让大家开怀大笑起来。

表演仍有条不紊地进行着。终于，最精彩、最搞笑、最耍宝的小品《选村长》粉墨登场了，当王悠表演到：“你就是会吹牛，有你基因的母鸡都会叫：咯咯咯——快看呀，快看呀，我给屈政世下了只松花皮蛋呀!”大家都忍不住捧腹大笑，我更是笑得眼泪都流出来了…… 一眨眼的功夫，元旦联欢会就结束了，可同学们依然沉浸在节日的欢乐中，久久不肯离去…… 欢乐的元旦联欢会日记篇三今天校园举行了盛大的“庆元旦”活动，我们都早早地到学校来庆元旦。活动开始了，我们一走到教室，就看到教室一片辉煌，教室中间有两条交叉的线。线上有五彩缤纷的彩带，中间 “来抓我啊，抓住我你也肯定猜不中。!” 先是学校的节目，是给去年报名“红十字” 了花。主持人继续选人上来读，我第一个被选到，而且全猜对了! “呼” 要会猜呢!” 大家听了我的答案后，都疑惑地说：“?”我得意洋洋地说：“当然有了，巴金爷爷在我的一本书里叫‘巴豆’“不对，是古代作家，自语地说：““是老子。”我们问她：“为什么呢?”周迎春胸有成竹地说：“”大家又想了几遍，说：“好，就它了。”我们飞速地排在对答案领 !七点五十分啦!我急忙做好准备，跑向了快乐作文学校。走进教室，教室里张灯结彩，同学们有说有笑，充满了喜气洋洋的气氛。令人期待的联欢会开始了，漂亮的主持人走上来，激动地说：“让我们来倒计时!十、九、八、七……!”砰!随着一声巨响，元旦联欢会开始了。主持人送来祝福，会场上热闹非凡，充满了欢声笑语，表演开始了，有唱歌的。有跳舞的，有吹葫芦丝的，真是应有尽有。但是令我印象最深刻的还是弹吉他这项节目。曹原弹的《龙的传人》得到了一阵阵掌声，陈鹏舟也不甘示弱，谈了一首《父亲》，更是得到了雷鸣般的掌声。

康复医学会“十二五”规划

中国康复医学会“十二五”发展规划纲要一、指导思想高举中国特色社会主义伟大旗帜，以邓小平理论和“三个代表”重要思想为指导，深入贯彻落实科学发展观，按照党的十七大和十七届三中、四中、五中全会精神和胡锦涛总书记在纪念中国科协成立50周年大会上的重要讲话要求，以国民经济和社会发展第十二个五年规划和国家中长期科技规划纲要为依据，根据中国科协“八大”的总体部署，坚持“三服务一加强”工作定位，把促进学科发展和为科技工作者服务放在更加突出的位置，在全面总结“十一五”期间取得的新成就的基础上，准确把握我国康复医学事业和学会发展的时代特征，团结带领广大科技工作者，紧紧围绕国家医疗卫生事业改革与发展大局，创新思路、找准位置、凝聚合力、展现特色，努力促进学会改革与学科建设的全面、协调、可持续发展，为建设创新型国家、构建和谐社会、夺取全面建设小康社会新胜利、推进中国特色社会主义伟大事业做出更大的贡献。二、总体目标。通过科学规划和采取有针对性的措施，夯实基础，凸显优势，培育品牌，引领创新。积极推进学会自身建设、学术交流、科学普及、人才培训、对外往来、决策咨询等各项业务的纵深发展，进一步强化桥梁和纽带功能，全面提升学会综合实力和社会影响，努力打造“功能完备，实力一流，运行规范、特色鲜明、政府信任、同行认可”的新型科技社团，创造无愧于祖国、无愧于时代的辉煌业绩。三、重点任务（一）主动承接政府职能，为加快经济发展方式转变服务 1.认真贯彻落实“防、治、康”三结合指导方针，提出决策咨询和政策建议。协助卫生部建立健全综合医院-康复医院-社区卫生服务中心一体化的康复医疗服务体系，优化康复医疗资源配置，加强和完善康复三级服务网络建设。2015年前在全国建立7个国家级区域康复医疗服务示范基地，在各省、自治区、直辖市各建立1所省级康复医疗服务示范基地，指导和带动区域内康复医学工作的全面发展； 2.协助卫生部贯彻落实《中国康复医学事业“十二五”发展规划》、《综合医院康复医学科建设与管理指南》、《康复医院建设标准与管理指南》等一系列推进学科发展的重大举

初中班级元旦晚会策划书

初中班级元旦晚会策划书第一部分晚会概况【班会组织能力】 1041班是一支有着极强凝聚力的队伍。组织机构健全，工作能力突出。回首往昔，我们已经成功举办了许多次精彩的主题班会，受到同学们的好评。我们将在工作中充分发挥团队优势，团结合作、共同努力，本着全心全意，全新改版，互惠互利的原则竭诚为您服务!班级元旦晚会策划书我们带着青春蓬勃的朝气和远大的志向来到1041班这个团结友爱的大家庭。我们筹备组打算通过举办迎新文艺晚会，师生共聚一堂，表达对同学们的关心与期望，让我们能更多地了解1041班的优秀文化，使我们能尽快地在高中生活当中找到自己的位置以进入角色。同时，我们通过这个文艺晚会发掘我们1041班的文艺人才，使他们的特长能得到更好的培养，还借它丰富大家的课余生活，提供一个展现个人魅力的舞台。【班会主题】这台文艺晚会的主题是“这个冬天不再冷”。我们需要得到各方面的关心和指导。有老师对学生互动的。所以这次晚会突出一个“爱”字，借联谊班会把大家的感情和祝愿表达出来，让他们能愉快的开始高中三年的学习和生活。【班会形式及内容】整个班会节目诸多，形式不限，内容尽量贴近高中生活贴近主题。具体的节目编排由班会筹备组负责和组织。所有节目需提前准备，经过节目策划组审查之后，合格的节目方可在这台文艺晚会上表演。节目演出次序由班会主持人和班会策划组决定。班会开始前五至十分钟，开始布置会场并入场。布置与入场期间，班会现场播放音乐和动态宣传的flash。班会进行时，可以使用各种活跃气氛的道具或横幅。整台班会从前至后都要拍摄记录。班会后，凡参加班会与演出的观众和演员都得到筹备组的感谢，并登记名字存档。通过班会嘉宾及观众代表的评选，班会将评选出最具创意节目奖两名，评出最佳表演奖两名，最佳歌手两名，同时通过班会嘉宾抽奖将抽出五位幸运观众。对于质量上乘的作品，可以在以后的主题班会上得到邀请函。【特色节目】 1、由开场节目(或由嘉宾上台致辞)，拉开班会的序幕。

六年级元旦联欢会文艺汇演

六年级四班元旦联欢会文艺汇演（王）：尊敬的老师（李）：Respect teacher （王）：亲爱的同学们（李）：dear students （合）：大家下午好！（王）：2013年的钟声即将敲响，时光的年轮又留下了一道深深地印痕。（李）：伴随着冬日里温暖得阳光，2013年元旦如约而至。（王）在这一刻，我们已经感受到了春的气息，这是我们的春天，这是我们这个大家庭的春天，更是我们每个人的春天。（李）：今天，哦我们相约在这里，享受缘分带给我们的快乐享受这段美好的时光：（王）：今天，我们相聚在这里，一起用心来感受真情，用爱来融化冰雪：（李）：今天我们相聚在这里，敞开你的心扉，，释放你的激情：（王）：今天，我们相聚在这里，这里将成为欢乐的海洋，让快乐响彻云霄！（李）：今天，我们欢聚一堂，载歌载舞：（王）：今天，我们激情满怀，心潮澎拜（李）：今天，我们送去我们的祝福。（王）：带着祝愿，带着嘱托：（李）：埋藏已久的期盼，化作今日相逢的喜悦。（王）：看，阳光灿烂，那是新年绚丽的色彩：（李）：听，金钟朗朗，这是新年动人的旋律。（王）：在诗与画流动的佳节里我宣布六年级四班元旦联欢会：（合）：现在开始！ 1.（李）：我们以开拓的步伐，超越自己！（王）：我们以创新的精神，走向世界！（李）：我们以《欢乐颂》的歌声，（合）：奔向未来！（王）：下面请欣赏王一斌、王志浩、常方鑫、张泽睿，为大家带来的《欢乐颂》

2.（李）：大家都看过《倾世皇妃》吗？（王）大家都听过《倾世皇妃》的主题曲《落花》吗？（李）落花是飘在锋利的一首诗，无声却叫人心动，（一咂嘴）这真是太美妙了。好了，不多说了，下面请欣赏陈逸群为大家演奏《落花》 3.（王）奔向你，让我们策马奔腾（李）奔向你，让我们踏遍红尘（合）奔向你，让赵紫涵和冯丽明为我们带来《奔向你》 4.（王）各位美女、各位帅哥们喜欢看搞笑的小品吗？今天呀，我们班里“骨灰级”的幽默高手，为了博大家一笑，为大家献上小品《我不知道》下面有请李佳怡，王雯静、陈金波。 5.（李）一直以来，人们只知道《欢乐颂》是贝多芬大师所作的曲，却不知道，大师是为席勒诗人的那首诗——欢乐颂所作的曲，今天我们将再一次听到风靡（mi）世界盛行不衰的歌曲，掌声有请 , , , ,为大家带来《欢乐颂》。 6.（王）前面一首《欢乐颂》扣进了我们的心弦（李）是呀，这是同学们精心准备的节目呢！（王）而魔术，更需要多加练习，（李）你会表演魔术？（王）我不会，但从浩宇同学会。（李）哦？那可是很期待呢？（王）接下来就有请欣赏从浩宇为大家表演《神奇的气球》 7.（李）同学们，看过一周立波秀吗？我们班的大才人聂一超撰写了一周成功秀，请大家欢笑一刻。有请聂一超、郝明睿、袁野、贾贝一、段成功，的精彩表演，大家准备好了吗？ 8.（王）叮叮当，叮叮当，铃儿响叮当…… （李）别吵了，都跑调了，吓死人了，还是请郭琪，田海宁、杨可奕来演唱吧！（眨一下眼） 9.（王）做一个优秀的主持人要处于与听众平等的位置上，少说废话，还要有素质，今天，我们超级四班要举行一个《主持人选拔大赛》，有请是陈雪，王雯

六年级元旦联欢会主持词

六年级元旦联欢会主持词 xx：尊敬的老师！男甲：亲爱的同学们！合：大家好！曹：今年是特殊的一年，今年是值得留恋的一年。男乙：因为，再过几个月，我们六年的小学生活就结束了。 xx：难忘的小学时代即将离去。男甲：充满期望的中学时代正向我们走来。曹：六年的时光转眼即逝，2000多个日夜仿佛就在昨天。男乙：今天，请允许我们向六(2)班全体师生拜最后一个早年。合：祝大家新年快乐，工作顺利，阖家幸福，心相事成，万事如意！赵：新年的钟声即将敲响，时光的车轮留下了小学里最后一道深深的印痕。男甲：伴随着冬日里温暖的阳光，2012年元旦如约而至。曹：回首刚刚过去的2011，我们十分荣耀。男乙：回首即将结束的六年生活，我们万分感激。赵：2011，六（2）班从成功走向更大的成功。男甲：小学六年，我们从不懂事的童年走向成熟的少年。合：这一切的一切，都离不开我们全体师生的努力。赵：今天，我们相聚在这里，享受缘分带给我们的欢乐，享受这段美好时光。曹：今天，我们相聚在这里，一起用心来感受真情，用爱来融化冰雪。男甲：今天，我们相聚在这里，敞开你的心扉，释放你的激情。

男乙：今天，我们相聚在这里，这里将成为欢乐的海洋，让快乐响彻云霄。赵：带着祝愿，带着嘱托，埋藏已久的期盼，化做你我的喜悦。男甲：看，阳光灿烂，那是新年绚丽的色彩。 xx：听，xx朗朗，这是新年动人的旋律。男乙：在诗与画流动的佳节里，我们一起来庆贺快乐的节目。合：xx小学六（2）班2012年元旦联欢会现在开始。 …… 结束语：赵：虽然我们无法阻拦时间的流逝，但是我们可以主宰自己的心情。男甲：妍丽的鲜花祝你节目愉快，闪动的目光传递平安如意。曹：愿你以微笑迎接青春的岁月和火一般的年华。男乙：愿来年梦幻般的鲜花与绿叶伴随着你，幸福永远。赵：让我们永远记住xx小学，我们成长的摇篮，我们梦起源的地方。男甲：在这里，有默默耕耘的园丁，有孜孜以求的学子。曹：在这里，散发着油墨的清香，跳动着青春的脉搏。男乙：相信xx的明天会更好！我们的明天会更好！合：最后，让我们一起唱响《感恩的心》，在动听的旋律中结束今天的联欢。