文档库 最新最全的文档下载
当前位置:文档库 › 高分子材料与工程专业英语翻译

高分子材料与工程专业英语翻译

高分子材料与工程专业英语翻译
高分子材料与工程专业英语翻译

A 高分子化学和高分子物理

UNIT 1 What are Polymer?

第一单元什么是高聚物?

What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt. To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands. These big molecules or ‘macro-molecules’are made up of much smaller molecules, can be of one or more chemical compounds. To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound. Alternatively, individual rings could be of different sizes and materials, and interlinked to represent a polymer from molecules of different compounds.

什么是高聚物?首先,他们是合成物和大分子,而且不同于低分子化合物,譬如说普通的盐。与低分子化合物不同的是,普通盐的分子量仅仅是58.5,而高聚物的分子量高于105,甚至大于106。这些大分子或“高分子”由许多小分子组成。小分子相互结合形成大分子,大分子能够是一种或多种化合物。举例说明,想象一组大小相同并由相同的材料制成的环。当这些环相互连接起来,可以把形成的链看成是具有同种分子量化合物组成的高聚物。另一方面,独特的环可以大小不同、材料不同,相连接后形成具有不同分子量化合物组成的聚合物。

This interlinking of many units has given the polymer its name, poly meaning ‘many’and mer meaning ‘part’(in Greek). As an example, a gaseous compound called butadiene, with a molecular weight of 54, combines nearly 4000 times and gives a polymer known as polybutadiene (a synthetic rubber) with about 200 000molecular weight. The low molecular weight compounds from which the polymers form are known as monomers. The picture is simply as follows:

许多单元相连接给予了聚合物一个名称,poly意味着“多、聚、重复”,mer意味着“链节、基体”(希腊语中)。例如:称为丁二烯的气态化合物,分子量为54,化合将近4000次,得到分子量大约为200000被称作聚丁二烯(合成橡胶)的高聚物。形成高聚物的低分子化合物称为单体。下面简单地描述一下形成过程:

butadiene + butadiene + ???+ butadiene--→polybutadiene

(4 000 time)

丁二烯+丁二烯+…+丁二烯——→聚丁二烯

(4000次)

One can thus see how a substance (monomer) with as small a molecule weight as 54 grow to become a giant molecule (polymer) of (54×4 000≈)200 000 molecular weight. It is essentially the ‘giantness’of the size of the polymer molecule that makes its behavior different from that of a commonly known chemical compound such as benzene. Solid benzene, for instance, melts

to become liquid benzene at 5.5℃and , on further heating, boils into gaseous benzene. As against this well-defined behavior of a simple chemical compound, a polymer like polyethylene does not melt sharply at one particular temperature into clean liquid. Instead, it becomes increasingly softer and, ultimately, turns into a very viscous, tacky molten mass. Further heating of this hot, viscous, molten polymer does convert it into various gases but it is no longer polyethylene. (Fig. 1.1) .

因而能够看到分子量仅为54的小分子物质(单体)如何逐渐形成分子量为200000的大分子(高聚物)。实质上,正是由于聚合物的巨大的分子尺寸才使其性能不同于象苯这样的一般化合物。例如,固态苯,在5.5℃熔融成液态苯,进一步加热,煮沸成气态苯。与这类简单化合物明确的行为相比,像聚乙烯这样的聚合物不能在某一特定的温度快速地熔融成纯净的液体。而聚合物变得越来越软,最终,变成十分粘稠的聚合物熔融体。将这种热而粘稠的聚合物熔融体进一步加热,不会转变成各种气体,但它不再是聚乙烯(如图1.1)。

固态苯——→液态苯——→气态苯

加热,5.5℃加热,80℃

固体聚乙烯——→熔化的聚乙烯——→各种分解产物-但不是聚乙烯

加热加热

图1.1 低分子量化合物(苯)和聚合物(聚乙烯)受热后的不同行为

Another striking difference with respect to the behavior of a polymer and that of a low molecular weight compound concerns the dissolution process. Let us take, for example, sodium chloride and add it slowly to s fixed quantity of water. The salt, which represents a low molecular weight compound, dissolves in water up to s point (called saturation point) but, thereafter, any further quantity added does not go into solution but settles at the bottom and just remains there as solid. The viscosity of the saturated salt solution is not very much different from that of water. But if we take a polymer instead, say, polyvinyl alcohol, and add it to a fixed quantity of water, the polymer does not go into solution immediately. The globules of polyvinyl alcohol first absorb water, swell and get distorted in shape and after a long time go into solution. Also, we can add a very large quantity of the polymer to the same quantity of water without the saturation point ever being reached. As more and more quantity of polymer is added to water, the time taken for the dissolution of the polymer obviously increases and the mix ultimately assumes a soft, dough-like consistency. Another peculiarity is that, in water, polyvinyl alcohol never retains its original powdery nature as the excess sodium chloride does in a saturated salt solution. In conclusion, we can say that (1) the long time taken by polyvinyl alcohol for dissolution, (2) the absence of a saturation point, and (3) the increase in the viscosity are all characteristics of a typical polymer being dissolved in a solvent and these characteristics are attributed mainly to the large molecular size of the polymer. The behavior of a low molecular weight compound and that of a polymer on dissolution are illustrated in Fig.1.2.

发现另一种不同的聚合物行为和低分子量化合物行为是关于溶解过程。例如,让我们研究一下,将氯化钠慢慢地添加到固定量的水中。盐,代表一种低分子量化合物,在水中达到点(叫饱和点)溶解,

但,此后,进一步添加盐不进入溶液中却沉到底部而保持原有的固体状态。饱和盐溶液的粘度与水的粘度不是十分不同,但是,如果我们用聚合物替代,譬如说,将聚乙烯醇添加到固定量的水中,聚合物不是马上进入到溶液中。聚乙烯醇颗粒首先吸水溶胀,发生形变,经过很长的时间以后进入到溶液中。同样地,我们可以将大量的聚合物加入到同样量的水中,不存在饱和点。将越来越多的聚合物加入水中,认为聚合物溶解的时间明显地增加,最终呈现柔软像面团一样粘稠的混合物。另一个特点是,在水中聚乙烯醇不会像过量的氯化钠在饱和盐溶液中那样能保持其初始的粉末状态。总之,我们可以讲(1)聚乙烯醇的溶解需要很长时间,(2)不存在饱和点,(3)粘度的增加是典型聚合物溶于溶液中的特性,这些特性主要归因于聚合物大分子的尺寸。如图1.2说明了低分子量化合物和聚合物的溶解行为。

氯化钠晶体加入到水中——→晶体进入到溶液中.溶液的粘度不是十分不同于

充分搅拌

水的粘度——→形成饱和溶液.剩余的晶体维持不溶解状态.

加入更多的晶体并搅拌

氯化钠的溶解

聚乙烯醇碎片加入到水中——→碎片开始溶胀——→碎片慢慢地进入到溶液中

允许维持现状充分搅拌

——→形成粘稠的聚合物溶液.溶液粘度十分高于水的粘度

继续搅拌

聚合物的溶解

图1.2 低分子量化合物(氯化钠)和聚合物(聚乙烯醇)不同的溶解行为

——Gowariker VR, Viswanathan N V, Sreedhar J. Polymer Science. New York:

John Wiley & Sons, 1986.6

UNIT 2 Chain Polymerization

第二单元链式聚合反应

Many olefinic and vinyl unsaturated compounds are able to form chain-0like macromolecules through elimination of the double bond, a phenomenon first recognized by Staudinger. Diolefins polymerize in the same manner, however, only one of the two double bonds is eliminated. Such reactions occur through the initial addition of a monomer molecule to an initiator radical or an initiator ion, by which the active state is transferred from the initiator to the added monomer. In the same way by means of a chain reaction, one monomer molecule after the other is added (2000~20000 monomers per second) until the active state is terminated through a different type of reaction. The polymerization is a chain reaction in two ways: because of the reaction kinetic and because as a reaction product one obtains a chain molecule. The length of the chain molecule is proportional to the kinetic chain length.

Staudinger第一个发现一例现象,许多烯烃和不饱和烯烃通过打开双键可以形成链式大分子。二烯烃以同样的方式聚合,然而,仅限于两个双键中的一个。这类反应是通过单体分子首先加成到引发剂自由基或引发剂离子上而进行的,靠这些反应活性中心由引发剂转移到被加成的单体上。以同样的方式,借助于链式反应,单体分子一个接一个地被加成(每秒2000~20000个单体)直到活性中心通过不同的反应类型而终止。聚合反应是链式反应的原因有两种:因为反应动力学和因为作为反应产物它是一种链

式分子。链分子的长度与动力学链长成正比。

One can summarize the process as follow (R. is equal to the initiator radical):

链式反应可以概括为以下过程(R?相当与引发剂自由基):略

One thus obtains polyvinylchloride from vinylchloride, or polystyrene from styrene, or polyethylene from ethylene, etc.

因而通过上述过程由氯乙烯得到聚氯乙烯,或由苯乙烯获得聚苯乙烯,或乙烯获得聚乙烯,等等。

The length of the chain molecules, measured by means of the degree of polymerization, can be varied over a large range through selection of suitable reaction conditions. Usually, with commercially prepared and utilized polymers, the degree of polymerization lies in the range of 1000 to 5000, but in many cases it can be below 500 and over 10000. This should not be interpreted to mean that all molecules of a certain polymeric material consist of 500, or 1000, or 5000 monomer units. In almost all cases, the polymeric material consists of a mixture of polymer molecules of different degrees of polymerization.

借助于聚合度估算的分子链长,在一个大范围内可以通过选择适宜的反应条件被改变。通常,通过大量地制备和利用聚合物,聚合度在1000~5000范围内,但在许多情况下可低于500、高于10000。这不应该把所有聚合物材料的分子量理解为由500,或1000,或5000个单体单元组成。在几乎所有的事例中,聚合物材料由不同聚合度的聚合物分子的混合物组成。

Polymerization, a chain reaction, occurs according to the same mechanism as the well-known chlorine-hydrogen reaction and the decomposition of phosegene.

聚合反应,链式反应,依照与众所周知的氯(气)-氢(气)反应和光气的分解机理进行。

The initiation reaction, which is the activation process of the double bond, can be brought about by heating, irradiation, ultrasonics, or initiators. The initiation of the chain reaction can be observed most clearly with radical or ionic initiators. These are energy-rich compounds which can add suitable unsaturated compounds (monomers) and maintain the activated radical, or ionic, state so that further monomer molecules can be added in the same manner. For the individual steps of the growth reaction one needs only a relatively small activation energy and therefore through a single activation step (the actual initiation reaction) a large number of olefin molecules are converted, as is implied by the term “chain reaction”. Because very small amounts of the initiator bring about the formation of a large amount of polymeric material (1:1000 to 1:1000), it is possible to regard polymerization from a superficial point of view as a catalytic reaction. For this reason, the initiators used in polymerization reactions are often designated as polymerization catalysts, even though, in the strictest sense, they are not true catalysts because the polymerization initiator enters into the reaction as a real partner and can be found chemically bound in the reaction product ,i.e. ,the polymer, In addition to the ionic and radical initiators there are now metal complex initiators (which can be obtained, for example, by the reaction of titanium tetrachloride or titanium trichloride with aluminum alkyls), which play an important role in polymerization reactions (Ziegler catalysts) ,The mechanism of their

catalytic action is not yet completely clear.

双键活化过程的引发剂反应,可以通过热、辐射、超声波或引发剂产生。用自由基型或离子型引发剂引发链式反应可以很清楚地进行观察。这些是高能态的化合物,它们能够加成不饱和化合物(单体)并保持自由基或离子活性中心以致单体可以以同样的方式进一步加成。对于增长反应的各个步骤,每一步仅需要相当少的活化能,因此通过一步简单的活化反应(即引发反应)即可将许多烯类单体分子转化成聚合物,这正如连锁反应这个术语的内涵那样。因为少量的引发剂引发形成大量的聚合物原料(1:1000~1:10000),从表面上看聚合反应很可能是催化反应。由于这个原因,通常把聚合反应的引发剂看作是聚合反应的引发剂,但是,严格地讲它们不是真正意义上的催化剂,因为聚合反应的催化剂进入到反应内部而成为一部分,同时可以在反应产物,既聚合物的末端发现。此外离子引发剂和自由基引发剂有的是金属络合物引发剂(例如,通过四氯化钛或三氯化钛与烷基铝的反应可以得到),Z引发剂在聚合反应中起到了重要作用,它们催化活动的机理还不是十分清楚。

UNIT 3 Step-Growth Polymerization

第三单元逐步聚合

Many different chemical reactions may be used to synthesize polymeric materials by step-growth polymerization. These include esterification, amidation, the formation of urethanes, aromatic substitution, etc. Polymerization proceeds by the reactions between two different functional groups, e.g., hydroxyl and carboxyl groups, or isocyanate and hydroxyl groups.

许多不同的化学反应通过逐步聚合可用于合成聚合材料。这些反应包括酯化、酰胺化、氨基甲酸酯、芳香族取代物的形成等。通过反应聚合反应在两种不同的官能团,如,羟基和羧基,或异氰酸酯和羟基之间。

All step-growth polymerization fall into two groups depending on the type of monomer(s) employed. The first involves two different polyfunctional monomers in which each monomer possesses only one type of functional group. A polyfunctional monomer is one with two or more functional groups per molecule. The second involves a single monomer containing both types of functional groups. The synthesis of polyamides illustrates both groups of polymerization reactions. Thus, polyamides can be obtained from the reaction of diamines with diacids

所有的逐步聚合反应根据所使用单体的类型可分为两类。第一类涉及两种不同的官能团单体,每一种单体仅具有一种官能团。一种多官能团单体每个分子有两个或多个官能团。第二类涉及含有两类官能团的单种单体。聚酰胺的合成说明了聚合反应的两个官能团。因此聚酰胺可以由二元胺和二元酸的反应或氨基酸之间的反应得到。

nH2N-R-NH2+nHO2C-R’-CO2H→

H-(-NH-R-NHCO-R’-CO-)n-OH+(2n-1)H2O (3.1)

or from the reaction of amino acids with themselves

nH2R-CO2H→H-(-NH-R-CO-)n-OH+(n-1)H20 (3.2)

The two groups of reactions can be represented in a general manner by the equations as follows

A+B-B →–[-A-A-B-B-]-A-B→–[-A-B-]-

两种官能团之间的反应一般来说可以通过下列反应式表示

反应式略

Reaction (3.1) illustrates the former, while (3.2) is of the latter type.

反应(3.1)说明前一种形式,而反应(3.2)具有后一种形式。

图3.1 逐步聚合的示意图

(a)未反应单体;(b)50%已反应;(c)83.3%已反应;(d) 100%已反应(虚线表示反应种类)Polyesterification, whether between diol and dibasic acid or intermolecularly between hydroxy acid molecules, is an example of a step-growth polymerization process. The esterification reaction occurs anywhere in the monomer matrix where two monomer molecules collide, and once the ester has formed, it, too, can react further by virtue of its still-reactive hydroxyl or carboxyl groups. The net effect of this is that monomer molecules are consumed rapidly without any large increase in molecular weight. Fig. 3.1 illustrates this phenomenon. Assume, for example, that each square in Fig. 3.a represents a molecule of hydroxy acid. After the initial dimmer molecules from (b), half the monomer molecules have been consumed and the average degree of polymerization (DP) of polymeric species is 2. As trimer and more dimer molecules form (c), more than 80% of the monomer molecules have reacted (d), DP is 4. But each polymer molecule that forms still has reactive end groups; hence the polymerization reaction will continue in a stepwise fashion, with each esterification of monomers. Thus, molecular weight increases slowly even at high levels of monomer conversion, and it will continue to increase until the viscosity build-up makes it mechanically too difficult to remove water of esterification or for reactive end groups to find each other.

聚酯化,是否在二元酸和二元醇或羟基酸分子间进行,是逐步聚合反应过程的一个例子。酯化反应出现在单体本体中两个单体分子相碰撞的位置,且酯一旦形成,依靠酯上仍有活性的羟基或羧基还可以进一步进行反应。酯化的结果是单体分子很快地被消耗掉,而分子量却没有多少增加。图3.1说明了这个现象。例如,假定图3.1中的每一个方格代表一个羟基酸分子。(b)中的二聚体分子,消耗二分之一的单体分子聚合物种类的聚合度(DP)是2。(c)中当三聚体和更多的二聚体形成,大于80%的单体分子已反应,但DP仅仅还是2.5。(d)中当所有的单体反应完,DP是4。但形成的每一种聚合物分子还有反应活性的端基;因此,聚合反应将以逐步的方式继续进行,其每一步酯化反应的反应速率和反应机理均与初始单体的酯化作用相同。因此,分子量缓慢增加直至高水平的单体转化率,而且分子量将继续增加直到粘度的增加使其难以除去酯化反应的水或难以找到相互反应的端基。

It can also be shown that in the A-A+B-B type of polymerization, an exact stoichiometric balance is necessary to achieve high molecular weights. If some monofunctional impurity is present, its reaction will limit the molecular weight by rendering a chain end inactive. Similarly, high-purity monomers are necessary in the A-B type of polycondensation and it follows that high-yield reactions are the only practical ones for polymer formation, since side reactions will upset the stoichiometric balance.

在A-A+B-B的聚合反应中也可以看到,精确的当量平衡是获得高分子量所必需的。假如存在一些但官能团杂质,由于链的端基失活,反应将使分子量减少。同样,在A-B类的缩聚反应中高纯度的单体是必要的,而且可以归结高收率的反应仅是形成聚合物的实际反应,因为副反应会破坏当量平衡。

-------Stevens M P. Polymer Chemistry. London: Addison-Wesley Publishing Company, 1975. 13

UNIT 4 Ionic Polymerization

第四单元离子聚合反应

Ionic polymerization, similar to radial polymerization, also has the mechanism of a chain reaction. The kinetics of ionic polymerization are, however, considerably different from that of radical polymerization.

离子聚合反应,与自由基聚合反应相似,也有链反应的机理。但是,离子聚合的动力学明显地不同于自由基聚合反应。

(1) The initiation reaction of ionic polymerization needs only a small activation energy. Therefore, the rate of polymerization depends only slightly on the temperature. Ionic polymerizations occur in many cases with explosive violence even at temperature. below 50℃(for example, the anionic polymerization of styrene at –70℃in tetrahydrofuran, or the cationic polymerization of isobutylene at –100℃in liquid ethylene ).

(1)离子聚合的引发反应仅需要很小的活化能。因此,聚合反应的速率仅对温度有较少的依赖性。在许多情况下离子聚合猛烈地发生甚至低于50℃(例如,苯乙烯的阴离子聚合反应在-70℃在四氢呋喃中,或异丁烯的阳离子聚合在-100℃在液态乙烯中)。

(2) With ionic polymerization there is no compulsory chain termination through recombination, because the growing chains can not react with each other. Chain termination takes place only through impurities, or through the addition of certain compounds such as water, alcohols, acids, amines, or oxygen, and in general through compounds which can react with polymerization ions under the formation of neutral compounds or inactive ionic species. If the initiators are only partly dissociated, the initiation reaction is an equilibrium reaction, where reaction in one direction gives rise to chain initiation and in the other direction to chain termination.

(2)对于离子聚合来说,不存在通过再结合反应而进行的强迫链终止,因为生长链之间不能发生链终止。链终止反应仅仅通过杂质而发生,或者说通过和某些像水、醇、酸、胺或氧这样的化合物进行加成而发生,且一般来说(链终止反应)可通过这样的化合物来进行,这种化合物在中性聚合物或没有聚合活性的离子型聚合物生成的过程中可以和活性聚合物离子进行反应。如果引发剂仅仅部分地离解,引发反应即为一个平衡反应,在出现平衡反应的场合,在一个方向上进行链引发反应,而在另一个方向上则发生链终止反应。

In general ionic polymerization polymerization can be initiated through acidic or basic compounds. For cationic polymerization, complexes of BF3, AlCl3, TiCl4, and SnCl4 with water, or alcohols, or tertiary oxonium salts have shown themselves to be particularly active. The positive ions are the ones that cause chain initiation. For example:

通常离子聚合反应能通过酸性或碱性化合物被引发。对于阳离子聚合反应来说,BF3,AlCl3,TiCl4和SnCl4与水、或乙醇,或叔烊盐的络合物提供了部分活性。正离子是产生链引发的化合物。例如:(反应略)

三乙基硼氟酸烊

However, also with HCl, H2SO4, and KHSO4, one can initiate cationic polymerization. Initiators

for anionic polymerization are alkali metals and their organic compounds, such as phenyllithium, butyllithium, phenyl sodium, and triphenylmethyl potassium, which are more or less strongly dissociated in different solvents. T o this group belong also the so called Alfin catalysts, which are a mixture of sodium isopropylate, allyl sodium, and sodium chloride.

然而,BF3也可以与HCl、H2SO4和KHSO4引发阳离子聚合反应。阴离子聚合反应的引发剂是碱金属和它们的有机金属化合物,例如苯基锂、丁基锂和三苯甲基锂,它们在不同的溶剂中或多或少地强烈分解。所谓的Alfin催化剂就是属于这一类,这类催化剂是异丙醇钠、烯丙基钠和氯化钠的混合物。

With BF3 (and isobutylene as the monomer), it was demonstrated that the polymerization is possible only in the presence of traces of traces of water or alcohol. If one eliminates the trace of water, BF3alone does not give rise to polymerization. Water or alcohols are necessary in order to allow the formation of the BF3-complex and the initiator cation according to the above reactions. However, one should not describe the water or the alcohol as a “cocatalyst”.

BF3为引发剂(异丁烯为单体),证明仅在痕量水或乙醇的存在下聚合反应是可以进行的。如果消除痕量的水,单纯的BF3不会引发聚合反应。按照上述反应为了能形成BF3-络合物和引发剂离子水或乙醇是必需的。但是不应将水或乙醇描述成“助催化剂”。

Just as by radical polymerization, one can also prepare copolymers by ionic polymerization, for example, anionic copolymers of styrene and butadiene, or cationic copolymers of isobutylene and styrene, or isobutylene and viny ethers, etc. As has been described in detail with radical polymerization, one can characterize each monomer pair by so-called reactivity ratios r1 and r2. The actual values of these two parameters are, however, different from those used for radical copolymerization.

正与自由基聚合反应一样,通过离子聚合反应也能制备共聚物,例如,苯乙烯-丁二烯阴离子共聚物,或异丁烯-苯乙烯阳离子共聚物,或异丁烯-乙烯基醚共聚物,等等。正如对自由基型聚合已经详细描述过那样,人们可以用所谓的竞聚率r1和r2来表征每单体对。然而,这两个参数的实际意义不同于那些用于自由基共聚合反应的参数。

---Vollmert B. Polymer Chemistry. Berlin: Sping-Verlag, 1973.163

PART B 聚合反应工程

UNIT 11 Reactor types

第十一单元反应器类型

Reactors may be categorized in a variety of ways, each appropriate to a particular perspective. For example, Henglein (1969) chooses a breakdown based on the source of energy used to initiate the reaction (i.e., thermal, electrochemical, photochemical, nuclear). More common breakdowns are according to the types of vessels and flows that exist.

反应器可以用许多方法分类,各自适用于特定的目的。例如,Henglein(1969)基于用于产生反应的能量来源,即,热量,电化学,光化学,原子核,选择了一种细目分类。更多普通的细目分类是按照所存在的容器和流量的类型。

1.Batch Reactors

1. 间歇反应器

The batch reactor (BR) is the almost universal choice in the chemist’s laboratory where most chemical processes originate. The reason is the simplicity and versatility of the batch reactor, whether it be a test tube, a three-neck flask, an autoclave, or a cell in a spectroscopic instrument. Regardless of the rate of the reaction, these are clearly low production rate devices. As scale up is desired, the most straightforward approach is to move to a larger batch reactor such as a large vat or tank.

间歇反应器在化学实验室几乎是一般的选择,大多数的化学过程在那里产生。间歇反应器的原理具简单性和通用性,不管它是一支试管,一个三颈瓶,一个高压釜,还是一个光谱仪器的比色皿。不管反应比例,很清楚这些是低产率设备。当要求放大反应器时,大多直截了当的途径是移至一个较大的间歇反应器如一个较大的大桶或罐。

Commercial batch reactors can be huge, 100 000 gal or more. The cycle time, often a day or more, typically becomes longer as reactor volume increases in order to achieve a substantial production rate with an inherently slow reaction. Fabrication, shipping, or other factors place a limit the size of a batch reactor. For example, transportation capacity can limit the size of a batch reactor for which shop, as opposed to on-site, fabrication of the heat exchange surface is required. This limits the production rates for which batch reactors may be economically utilized. Also, batch reactors must be filled, emptied, and cleaned. For fast reactions these unproductive operations consume far more time than the reaction itself and continuous processes can become more attractive.

商业化的间歇反应器是庞大的,10万加仑或更大。对于慢化学反应,为提高生产率必须增加反应器体积,而这往往导致反应器的循环周期变长,常常以天计算。制造、运输以及其他因素限制了反应器的规模,如热传递能力会限制间歇反应器的尺寸,热交换器必须在制造厂而不是在现场加工。这限制了产率由于这间歇反应器可以被经济地利用。间歇反应器也必须装料、卸料和清洗。为了加快反应这些非生产性的操作消耗了多于反应本身的时间,连续化过程可能更有吸引力。

2. Semibatch Reactors (SBR)

2.半间歇反应器

Some reactions may yield a product in a different phase from the reaction mixture. Examples would be liberation of a gas from a liquid-phase reaction or the formation of a precipitate in a fluid-phase reaction. To drive the reaction to completion, it may be desirable to continuously separate the raw product phase. A semibatch operation may result as well from differing modes of feeding the individual reactants. For reasons we will discuss later, it may be desirable to charge one reactant to the reactor at the outset and bleed a second reactant in continuously over time. Such reactors have both a batch and a flow character and, like batch reactors, are useful for slow reactions and low production rates.

一些反应器可以从反应混合物的不同相态中生产出某种产品。例如液相反应中气体的释放,或流动相反应中沉淀的生成。为了驱使反应完全,希望继续分离粗产物相。个别反应物的不同加入方式也导致半连续操作。原因我们以后讨论,可希望一开始加入一种反应物以后连续加入第二种反应物。这类反应器同时具有一个间歇和一个流动的特征,像间歇反应器,适用于慢反应和低产率。

3. Continuous Stirred T ank Reactors (CSTR)

3. 连续流动搅拌反应器

It is a small step from the batch reactor to the CSTR. The same stirred vessel may be used with only the addition of piping and storage tanks to provide for the continuous in-and outflow. Faster reactions can be accommodated and larger production rates can be achieved because of the uninterrupted operation. CSTRs are most often used for liquid-phase reactions, such as nitration and hydrolysis, and multiphase reactions involving liquid with gases and/or solids. Examples would be chlorination and hydrogenation.

从间歇反应器到连续流动搅拌反应器是小小的一步。同样的搅拌式容器的使用可仅仅添加管道和储罐以提供连续进料和出料。因为连续操作可加快反应并提高产率。通常大多数连续流动搅拌反应器用于液相反应,例如硝化和水解,多相反应器涉及液-气和/或液-固。例如氯化和加氢。

4. CSTR in Series

4.多级串联连续流动搅拌反应器

It was shown that considerable gains in production rate and economics can be achieved by passing the reacting mixture through a series of CSTRs. Again, we see how easy it is to achieve a gradual scale up, say for a specialty chemical for which is increasing. CSTRs in series are usually used for liquid-phase reactions.

事实证明通过一系列多级串联连续流动搅拌反应器的混合能够获得高产率和重大的经济效益。再者,这种反应器容易放大,例如某种化学品的需求逐步增加时常这样做。多级串联连续流动搅拌反应器通常用于液相反应。

5.Tubular Reactors

5.管式反应器

As the production rate requirement increases, batteries of CSTRs become increasingly complex and tubular reactors become attractive. With the transition to tubular reactors, some versatility is lost and more process integration is required. Nevertheless, tubular reactors find extensive application in liquid-phase reactions, for example, polymerization, and are almost always the continuous reactor of choice for gas-phase reactions, for example, pyrolysis. Exceedingly high production rates can be achieved with tubular reactors either by increasing the diameter of the tube or more commonly by using a sufficient number of tubes in parallel.

当产率需要增加时,增加许多套连续搅拌式反应器变得复杂,而管式反应器变得诱人。转化成管式反应器失去了一些通用性并要求综合许多操作。尽管如此,管式反应器在液相反应中起着广泛作用,例如,聚合反应,气-液反应几乎总是选择连续反应器,例如,高温裂解。采用管式反应器能够获得非常高的产率,要么增加管的直径要么通过使用充足数量的并列管提高更大的通用性。

6. Recycle reactors

6. 循环反应器

Recycle reactor can be batch, CSTR, tubular, and so on in nature with the purpose of the recycle varying from one case to the next. Many large-scale commercial processes incorporate the recycle of one or more streams back to an earlier point in the process to conserve raw materials. This practice often results in the accumulation of impurities, which in turn requires

separation. Usually it is not simply the reactor outlet stream that is recycled back to the reactor inlet, but it can be. For example in a batch reactor the reacting mixture can be recycled, or pumped around, through a heat exchanger to provide thermal control.

循环反应器出于从一种情况到下一种情况循环变化的目的,在种类上可以是间歇反应器、连续流动搅拌反应器、管式反应器等等。回到较早的观点,在节省粗原料的过程中,许多大规模的商业操作合并了一个或多个循环。这一实践通常导致了杂质的累积,它们依次需要分离。通常不是简单地将反应器的出料返回到入口,当然也可以这样做。例如,在间歇反应器中反应混合物可以回收,或用泵打循环,通过热交换器控制热。

Recycle reactor have also found valuable application in the laboratory and pilot plant because of their special characteristics. At one extreme, in which all of the product is recycled (no net flow), the reactor is the exact equivalent of the well-stirred batch reactor. At the other extreme of no recycle, the reactor is simply the tubular variety. If there is some net flow but the recycle rate is high, the overall reactor performs like a CSTR. Yet the reaction tube itself behaves like differential tubular reactor. This versatility of the recycle reactor can be exploited to great advantage in research and development.

循环反应器由于其特殊的特性在实验室和中试车间也发现了应用价值。一个极端是将所有的产物循环(没有净的流出),此时循环反应器严格等效于全混间歇反应器。另一个极端是没有循环,反应器是简单的管式类。假如有一些净的流出但循环率很高,所有的反应器运行类似于连续流动搅拌反应器。然而反应器本身的类似于不同的管式反应器。在研究和发展中循环反应器的通用性能够开发出更大的优点(势)。

——Bisio A. , Kabel R L. Scaleup of Chemical Processes. New York: John Wiley & Sons

Inc. , 1985. 255~257

T 14 Styrene-Butadiene Copolymer

第十四单元丁二烯-苯乙烯共聚物

The synthetic rubber industry, based on the free-radical emulsion process, was created almost overnight during World War II. Styrene-butadiene (GR-S) rubber crated at that time gives such good tire treads that natural rubber has never regained this market.

合成橡胶工业,以自由基乳液过程为基础,在第二次世界大战期间几乎很快地形成。那时,丁苯橡胶制造的轮胎性能相当优越,使天然橡胶在市场黯然失色。

The GR-S standard recipe is

丁苯橡胶的标准制法是

组分重量分数组分重量分数

丁二烯72 过硫酸钾0.3

苯乙烯25 肥皂片 5.0 十二烷基硫醇0.5 水180

This mixture is heated with stirring and at 50℃gives conversions of 5%~6% per hour. Polymerization is terminated at 70%~75% conversion by addition of a “short-stop”, such as hydroquinone (approximately 0.1 part), to quench radicals and prevent excessive branching and microgel formation. Unreacted butadiene is removed by flash distillation, and syrene by steam-stripping in a column. After addition of an antioxidant, such as N-phenyl-β-naphthylamine (PBNA) (1.25 parts), the latex is coagulated by the addition of brine, followed by dilute sulfuric acid or aluminum sulfate. The coagulated crumb is washed, dried, and baled for shipment.

混合物在搅拌下50℃加热,每小时转化5%~6%,在转化率达70%~75%时通过加入“终止剂”聚合反应终止,例如对苯二酚(大约0.1的重量百分含量),抑制自由基并避免过量支化和微凝胶形成。未反应的丁二烯通过闪蒸去除,苯乙烯在萃取塔中通过蒸汽萃取(剥离)。在加入抗氧剂后,例如N-甲基-β-萘胺(1.25的重量百分含量),加入盐水,其次加入稀释的硫酸或硫酸铝后乳液凝胶。凝胶碎片被洗涤、干燥并包装装运。

Fig.14.1 SBR plant flow diagram Courtesy of Hydrocarbon Processing and Petroleum Refiner.

图14.1 丁苯橡胶厂流程图取自烃类加工和石油产品精制

This procedure is still the basis for emulsion polymerization today. An important improvement is continuous processing illustrated in Fig. 14.1; computer modeling has also been described.

今天这种生产过程仍是胶体聚合反应的基础。如图14.1所示一个重要的进步是连续操作;也采用计算机模型描述。

In the continuous process, styrene, butadiene, soap, initiator, and activator (an auxiliary initiating agent) are pumped continuously form storage tanks through a series of agitated reactors at such a rate that the desired degree of conversion is reached at the last reactor. Shortstop is added, the latex warmed with steam, and the unreacted butadiene flashed off. Excess styrene is steam-stripped, and the latex finished as shown in Fig. 14.1.

在连续操作中,苯乙烯、丁二烯、肥皂、引发剂和活化剂(一种助引发剂)用泵从储罐通过一系列

的混合反应器,泵送流率根据末釜的转化率控制。加入终止剂,乳液用蒸气加热,未反应的丁二烯被闪蒸。剩余的苯乙烯被蒸气剥离,如图14.1表示乳液完成。

表14.1 冷丁苯胶的典型配方

组分配方1 配方2

丁二烯72 71

苯乙烯28 29

特十二烷基硫醇0.2 0.18

过氧化二异丙苯0.08

过氧化薄荷烷0.08

硫酸亚铁七水合物0.14 0.03

焦磷酸钾0.18

磷酸钠十水合物0.5

乙二胺四乙酸钠0.035

甲醛次硫酸钠0.08

松香酸 4.0 4.5

水180 200

SBR prepared from the original GR-S recipe is often called hot rubber; cold rubber is made at 5℃by using a more active initiator system. Typical recipes are given in T able 14.1 At 5℃,60% conversion to polymer occurs in 12~15h.

由常规丁苯制法制备的丁苯胶常称作热胶;冷胶通过使用一种更高活性的引发体系在5℃制成。典型的配方在表14.1中给出。5℃、60%转化率、12~15 h聚合物形成。

Cold SBR tire treads are superior to those of hot SBR. Polymers with abnormally high molecular weight (and consequently too tough to process by ordinary factory equipment) can

be processed after the addition of up to 50 parts of petroleum-base oils per hundred parts of rubber (phr). These oil extenders make the rubbers more processible at lower cost and with little sacrifice in properties; they are usually emulsified and blended with the latex before coagulation.

冷丁苯橡胶轮胎优于那些热丁苯胶。具有异常高的分子量的聚合物(因此采用常规的工厂设备由于太粘稠而难以加工)在每一百份的橡胶中加入大于50份的石油基础油后能够加工。这些油添加剂使橡胶更易加工体现在低成本和性能方面低损耗;他们在凝胶之前通常乳化并与胶乳混合。

Recent trends have been toward products designed for specific uses. The color of SBR, which is important in many nontire uses, has been improved by the use of lighter-colored soaps, shortstops, antioxidants, and extending oils. For example, dithiocarbamates are substituted for hydroquinone as shortstop; the latter is used on hot SBR where dark color is not objectionable.

A shortstop such as sodium dimethyldithiocarbamate is more effective in terminating radicals and destroying peroxides at the lower temperatures employed for the cold rubbers.

最近倾向于设计特殊用途的产品。丁苯橡胶的颜色,在许多非轮胎使用中十分重要,通过使用浅色的肥皂、终止剂、抗氧剂和扩展油加以改进。例如,二硫化氨基甲酸盐替代对苯二酚作为终止剂;后者适用于不被人反对的黑色丁苯橡胶。在冷胶的制备中如二硫化氨基甲酸钠的终止剂在低温情况下对终止自由基和消灭过氧化物更有效。

Free-radical dissociative initiators that function by dissociation of a molecule or ion into two radical species are normally limited to inorganic persulfates in the case of butadiene polymerization.

在丁二烯聚合反应过程中自由基分解的引发剂即一分子分解或离子成两个自由基物种的引发剂通常限制于过硫酸盐。

The other important class of free-radical initiators, redox systems, contain two or more components that react to produce free radicals. Dodecyl mercaptan added to control molecular weight also appears to aid free-radical formation by reaction with persulfate. The commercial importance of such chain-transfer agents or modifiers cannot be overemphasized. Without molecular weight control the rubbers would be too tough to process.

其他重要的自由基引发剂类别,氧化还原体系,包含反应产生自由基的两种或多种组分。加入控制分子量的十二烷基硫醇与过硫酸盐反应也出现了助自由基的形成。这种链转移剂或调节剂具有极其重要的商业价值。不控制分子量橡胶将过于粘稠难以加工。

--------T ate D p , Bechea T W. Encyclopedia of Polymer Science and Engineering, 2nd ed.

Vol. 2. Editor-in-chilf Kroschwitz JI. New York: John wiley & Sons, 1985. 553~555

C 聚合物材料的加工、性能和应用

UNIT 21 Polymer Processing

第二十一单元聚合物加工

Polymer processing , in its most general context , involves the transformation of a solid ( sometimes liquid ) polymeric resin , which is in a random form (e. g. powder, pellets , beads ), to a solid plastics product of specified shape , dimensions , and properties. This is achieved by

means of a transformation process: extrusion, molding, calendering , coating , thermoforming , etc. The process, in order to achieve the above objective, usually involves the following operations: solid transport , compression, heating, melting, mixing, shaping, cooling, solidification, and finishing . Obviously, these operations do not necessarily occur in sequence, and many of them take place simultaneously.

在其最一般的情况下,聚合物加工涉及固体(有时侯是液体)聚合物树脂以一种不规则的形式(例如粉末、颗粒、珠子)转化成一种具有特殊形状、尺寸和性能的固体塑料产品。这借助于转换加工:挤出、模塑、压延、涂敷、热成型等。为了获得上述目的,加工通常涉及下述操作:固体输送、压缩、加热、混合、成型、冷却、固化并完成。显然,这些操作不必按序发生,而许多可以同时发生。

Shaping is required in order to impart to the material the desired geometry and dimensions. It involves combinations of viscoelastic deformations and heat transfer, which are generally associated with solidification of the product from the melt. 成型是为了给予材料所需要的几何形状和尺寸。它涉及粘弹形变和热传递,这种粘弹形变和热传递是和产品从熔体的固化(或冷却)相联系的。

Shaping includes : (1) two-dimensional operations , e.g. dieforming, calendering and coating , and (2) three-dimensional molding and forming operations. Two-dimensional processes are either of the continuous , steady state type )e.g. film and sheet extrusion , wire coating , paper and sheet coating ,calendering ,fiber spinning , pipe and profile extrusion , etc. ) or intermittent as in the case of extrusions associated with intermittent extrusion blow moulding. Generally, moulding operations are intermittent, and, thus, they tend to involve unsteady state conditions. Thermoforming, vacuum forming, and similar processes may be considered as secondary shaping operations, since they usually involve the reshaping of an already shaped form. In some cases, like blow molding, the process involve primary shaping (parison formation) and secondary shaping (parison inflation ).

成型包括:(1)二元操作,例如,口模成型、压延和涂敷,(2)三元的模型和成型操作。二元的操作要么是连续的,固定形状(例如薄膜和板材,电线涂布,纸和平面涂布,压延,纤维拉伸,管材和型材挤出等等。)要么是间歇式的,在挤出的情况下伴有间歇挤出吹膜。通常,模塑操作是间歇的,然而同时倾向于非固定条件。热成型,真空成型,和相似的加工可以认为是二次成型操作,因为它们通常包括已成型形状的再次成型。在某些情况下像吹模,加工包括首次成型(型胚成型)和二次成型(型胚膨胀)。

Shaping operations involve simultaneous or staggered fluid flow and heat transfer. In two-dimensional processes, solidification usually follows the shaping process, whereas solidification and shaping tend to take place simultaneously inside the mold in three dimensional processes. Flow regimes, depending on the nature of the material, the equipment, and the processing conditions, usually involve combinations of shear, extensional, and squeezing flows in conjunction with enclosed (contained) or free surface flows.

成型操作包括同时或交叉的液体流动和热传递。在二元加工中,固化(或冷却)伴随着成型加工,反之在三元加工的模塑中固化(或冷却)和成型倾向于同时发生。根据材料的性质、设备和加工条件,

流动状态以及根据流动面的自由与否,通常包括剪切、延伸和挤压流动。

The thermo-mechanical history experienced by the polymer during flow and solidification results in the development of microstructure (morphology, crystallinity, and orientation distributions) in the manufactured article. The ultimate properties of the article are closely related to the microstructure. Therefore, the control of the process and product quality must be based on an understanding of the interactions between resin properties, equipment design, operating conditions, thermo-mechanical history, microstructure, and ultimate product properties. Mathematical modeling and computer simulation have been employed to obtain an understanding of these interactions. Such an approach has gained more importance in view of the expanding utilization of computer aided design/computer assisted manufacturing/computer aided engineering (CAD/CAM/CAE) systems in conjunction with plastics processing.

经历了流动和固化(或冷却)的聚合物热机械过程导致了制造业微结构的变革(形态学、结晶学和取向分布)。最终产品的性能与微结构紧密相关。因此,加工和产品质量的控制必须基于树脂性能、设备设计、操作条件、热机械过程、微结构和最终产品性能之间相互作用的理解。数学模型和计算机被同时用于获得这些相互作用的理解。鉴于进一步利用计算机辅助设计/计算机辅助制造/计算机辅助工程(CD/CAM/CAE)系统协同塑料加工诸如这一趋近获得了更多的重要性。

The following discussion will highlight some of the basic concepts involved in plastics shaping operations. It will emphasize recent developments relating to the analysis and simulation of some important commercial processes, with due consideration to elucidation of both thermo-mechanical history and microstructure development. More extensive reviews of the subject can be found in standard references on the topic (1~6).

下面的讨论将重点放在包括塑料成型操作一些基本概念上。适当考虑说明热机械过程和微结构发展,将强调最近关于分析和一些重要商品加工模型的进展。在上端(1~6)的标准参考中能够找到本主题更广泛的综述。

As mentioned above, shaping operations involve combinations of fluid flow and heat transfer, with phase change, of a visco-elastic polymer melt. Both steady and unsteady state processes are encountered. A scientific analysis of operations of this type requires solving the relevant equations of continuity, motion, and energy (i.e. conservation equations).

如上面提到的,成型操作包括液体流动和热传递,对于相态变化,还包括粘弹性聚合物的熔融。稳定和非稳定状态加工是相冲突的。这种典型操作的科学分析需要解决相关连续、运转和能量平衡(如守恒方程)。

——

Austarita G , Nicolas L. Polymer prscessing and properties

New York: Plenum press 1984, 1~3

UNIT 29 Synthetic Plastics

第二十九单元合成塑料

It would be difficult to visualise our modern world without plastics. Today they are an

integral part of everyones lifestyle with applications varying from commonplace articles to sophisticated scientific and medical instruments. Nowadays designers and engineers readily turn to plastics because they offer combinations of properties not available in any other materials. Plastics offer advantages such as lightness , resilience , resistance to corrosion , colour fastness , transparency , ease of processing , etc. , and although they also have their limitations , their exploitation is limited only by the ingenuity of the designer.

现代社会没有塑料真是难以想象。今天它们是组成每个人生活的必备部分,从不断变化的平凡物品到尖端科技的医学仪器。当今的设计师和工程师已开始着手塑料的研究,因为它们提供了不能应用于任何其它材料的综合性能。塑料所呈现的优点诸如质轻、弹性、防腐、不易褪色、透明性、易于加工等等,尽管也有它们的制约,它们的开发仅因设计师的创造力受到限制。

It is usual to think that plastics are a relatively recent development but in fact, as part of the larger family called “polymers”, they are a basic ingredient of plant and animal life. Polymers are materials which consist of very long chain-like molecules. Natural materials such as silk, shellac, bitumen, rubber and cellulose have this type of structure. However, it was not until the 19th century that attempts were made to develop a synthetic polymeric material and the first success was based on cellulose. This was a material called “Parkesine”, after its inventor Alexander Parkes, and although it was not a commercial success it was a start and eventually led to the development of “Celluoid”. This material was an important break-through because it became established as a good replacement of natural materials which were in short supply .

通常认为塑料是一种相对新的发展,但事实上作为“聚合物”大家族的成员,它们是动植物生活的一个基本组成部分。聚合物是由象链一样非常长的分子组成的材料。象丝、虫胶、沥青、橡胶和纤维素之类的天然材料有这种类型的结构。然而,直到19世纪才尝试开发了一种合成聚合物材料,首次成功基于赛璐珞。这是一种叫做“硝化纤维素塑料”的材料,它的发明者是Alexander Parkes ,尽管不是一种开始的商业成功,最终导致了“赛璐珞”的发展。这种材料是一个重要的突破因为它成为了供应短缺的天然材料的良好替代品。

During the early twentieth century there was considerable interest in these new synthetic materials. Phenol-formaldehyde (“bakelite”) was introduced in 1905 and about the time of the second World War materials such as nylon, polyethylene and acrylic (“Perspex”) appeared on the scene. Unfortunately many of the early applications for plastics earned them a reputation as being cheap substitutes. It has taken them a long time to overcome this image but nowadays the special properties of plastics are being appreciated which is establishing them as important materials in their own right. The ever increasing use of plastics in all kinds of applications means that it is essential for designers and engineers to become familiar with the range of plastics available and the types of performance characteristics to be expected so that they can be used to the best advantage.

二十世纪初,人们十分关注这些新合成材料。酚醛树脂(“电木粉”)于1905年问世,大约在第二次世界大战期间象尼龙、聚乙烯和丙烯酸类(“有机玻璃”)的材料相继出现。可惜塑料的许多早期应用带来的是廉价代用品的名声。这种印象花费了长久的时间才被消除,但如今,塑料的特性正在被人们认识到,而塑料也正在确立它们作为重要材料的地位。塑料在各种应用中的用途不断增加,这意味着对于

设计师和工程师来说,通晓塑料应用的范围和预期的性能特征是十分必要的,以致能以最好的方式利用它们。

The words “polymers”and “plastics”are often taken as synonymous but in fact there is a distinction. The polymer is the pure material which results form the process of polymerisation and is usually taken as the family name for materials which have long chain-like molecules and this includes rubber. Pure polymers are seldom used on their own and it is when additives are present that the term plastic is applied. Polymers contain additives for a number of reasons. In some cases impurities are present as a result of the polymerisation additives such as stabilisers, lubricants, fillers, pigments, etc., are added to enhance the properties of the material.

单词“聚合物”和“塑料”通常被看作是同义的,但事实上是有区别的。聚合物是缘于聚合反应过程的纯物质,常常被看作具有长链分子材料的系列名称,这也包括橡胶。纯的聚合物很少独自使用,当存在添加剂时它适用于专有名词塑料。由许多原因聚合物含有添加剂。在某些情况下作为聚合反应的结果存在杂质,去除这些杂质以获得纯的聚合物可能是不经济的。在其它情况下,添加象稳定剂、润滑剂、填充剂、颜料等之类的添加剂,以增强材料的性能。

There are two important classes of plastics:

有两种重要类别的塑料:

(1)Thermoplastic materials. In a thermoplastic material the long chain-like molecules are held together by relatively weak Van der Waals forces. A useful image of the structure is a mass of randomly distributed long strands of sticky wool. When the material is heated the intermolecular forces are weakened so that is becomes soft and flexible and eventually, at high temperatures, it is a viscous melt. When the material is allowed to cool it solidifies again. This cycle of softening by heat and solidifying when cooled can be repeated more or less indefinitely and is a definite advantage in that it is the basis of most processing methods for these materials. It does have its drawbacks, however, because it means that the properties of thermoplastics are heat sensitive. A useful analogy which is often used to describe these materials is that like candle wax they can be repeatedly softened by heat and will solidify when cooled.

(1)热塑性材料。在热塑性材料中象长链一样的分子间力是相对较弱的范德华力。对于结构一个有效的比喻是一大团自由分布的粘性纤维长线。当材料被加热时,内部的分子作用力变弱,以致变得柔软和柔韧,最终在高温下,成为粘性熔融体。当材料被冷却时再次固化。加热软化、冷却固化大体上能反复多次地循环,对于材料这是一个明显的优点,也是许多加工方法的基础。然而,热塑性材料的确有其缺点,因为这意味着热塑性塑料的特性是热敏的。常常用于描述这些材料的有效比拟是象烛蜡加热能够反复软化而当冷却时又将固化。

Examples of thermoplastics are polyethylene, polyvinyl chloride, polystyrene, nylon, cellulose acetate, acetal, polycarbonate, polymethyl methacrylate and polypropylene.

热塑性塑料的例子是聚乙烯、聚氯乙烯、聚苯乙烯、尼龙、醋酸纤维素、聚甲醛、聚碳酸酯、聚甲基丙烯酸甲酯和聚丙烯。

(2)Thermosetting materials. A thermosetting material is produced by a chemical reaction which has two stages. The first stage results in the formation of long chain-like molecules similar to those present in thermoplastics, but still capable of further reaction. The second stage

of the reaction takes place during moulding, usually under the application of heat and pressure. The resultant moulding will be rigid when cooled but a close network structure has been set up within the material. During the second stage the long molecular chains have been interlinked by strong bonds so that the material cannot be softened again by the application of heat. If excess heat is applied to these materials they will char and degrade. This type of behaviour is analogous to boiling an egg. Once the egg has cooled and is hard, it cannot be softened again by the application of heat.

(2)热固性材料。热固性材料是通过两步化学反应生产而来的。第一步形成类似于存在于热塑性塑料中象长链一样的分子形式,但还能够进一步反应。第二步反应在模塑时发生,通常在加热加压条件下进行。当冷却时最终的模塑将是刚硬的,但在材料中建立了封闭的网状结构。在第二步反应中长分子链通过强键相互连接,所以材料加热不再软化。如果将这些材料超高温加热将炭化并分解。这种行为类似于煮熟的鸡蛋。一旦鸡蛋冷却则变硬,加热不能再次软化。

Since the cross-linking of the molecules is by strong chemical bonds thermosetting materials are characteristically quite rigid materials and their mechanical properties are not heat sensitive. Examples of thermosets are phenol formaldehyed, melamine formaldehyde, urea formaldehyde, epoxies and some polyesters.

因为由强化学键交链的热固性塑料十分刚硬,它们的机理性能不是热敏的。热固性塑料的例子是酚醛树脂、胺醛树脂、脲醛树脂、环氧树脂和一些聚酯。

自动化专业英语考试翻译

PART 3 Computer Control Technology UNIT 1 A 计算机的结构与功能 这一节介绍计算机的内部体系结构,描述了指令如何存储和译码,并解释了指令执行周期怎样分解成不同的部分。 从最基本的水平来讲,计算机简单执行存储在存储器中的二进制编码指令。这些指令按照二进制编码数据来产生二进制编码结果。对于通用可编程计算机,四个必要部件是存储器、中央处理单元(CPU,或简称处理器),外部处理器总线,输入/输出系统,正如图 3-1A-1所示。 外部处理器总线 存储器CPU输入/输出 图 3-1A-1 计算机的基本元件 存储器储存指令和数据。 CPU读取和解释指令,读每条指令所需的数据,执行指令所需的操作,将结果存回存储器。CPU所需的操作之一是从外部设备读取或写入数据。这利用输入/输出系统来实现。 外部处理器总线是一套能在其他计算机部件之间传送数据、地址和控制信息的电导线。 存储器 计算机的存储器是由一套连续编号的单元所组成。每个存储单元是一个能存二进制信息的寄存器。单元的编号称为地址。初始地址为0。制造商定义处理器的一个字长为单元的整数长。在每个字中,各位表示数据或指令。对于英特尔8086/87和摩托罗拉MC68000微处理器来说,一个字是16位长,但每个存储单元仅为8位,因此两个8位单元来存取获得一个数据字长。

为了使用存储器中的内容,处理器必须取来右边的内容。为了完成这一次读取,处理器把所需单元的二进制编码地址放到外部处理器地址总线的地址线上,然后,存储器允许处理器读取所寻址的存储单元的内容。读取存储单元的内容的这一过程并不改变该单元的内容。 存储器中的指令存储器中的指令由CPU取来。除非发生程序转移,它们按在存储器中出现的顺序来执行。用二进制形式所写的指令叫做机器语言指令。一种得到(指令)有效形式的方法是将(这些)位分成段,如图3-1A-2所示。每一段都包含一个不同类型信息的代码。 在简单的计算机中,每条指令可分为四段,每段有四位。每条指令包括操作代码(或操作码,每条指令有唯一的操作码)、操作数地址、立即数、转换地址。 在一个实际的指令集中,有很多指令。也有大量的存储单元来存储指令和数据。为了增加存储单元的数目,如果我们使用同样的方法,地址段的指令一定长于16位。除了增加指令长度外,还有很多增加微处理器寻址范围的方法:可变指令段、多字指令、多寻址模式,可变指令长度。我们不将详细讨论它们。 存储数据数据是存储器中代表代码的信息。为了有效利用存储空间和处理时间,大多数计算机提供了不同长度和表示方法的处理数据能力。能被处理器识别的各种不同表示称作数据类型。常用的数据类型有:位、二进制码、十进制数字(4位字节,BCD)、字节(8位)、字(2个字节)、双字(4个字节)。 有一些处理器提供了可处理其他数据类型。例如单精度浮点数据类(32位)和双精度浮点数据(64位)等的指令。还有另一类的数据–––特征数据。通常也表示为8位。在标准键盘上,每个计算机终端键和键的组合(例如shift和control功能键)有定为美国信息交换标准码的7位码。 存储器类型在数字控制系统的应用中,我们也关注不同存储技术的特征。对主存储器来说,我们需用它临时存储信息,并逐次地从不同单元写入或获得信息。这种类型的存储器称作随机访问存储器(RAM)。在某些情况下,我们不想让存储器中的信息丢失。因此我们愿使用特殊技术写入存储器。如果写入只在物理改变连接时才能实现,那么这种存储器称为只读存储器(ROM)。如果相互连接的模式可由程序设定,那存储器叫做可编程只读存储器(PROM)。如果需要实现改写的情况,我们有可擦的可编程只读存储器(EPROM)。电可擦除的PROM缩写为EEPROM。

高分子材料与工程专业英语翻译

A 高分子化学和高分子物理 UNIT 1 What are Polymer? 第一单元什么是高聚物? What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt. To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands. These big molecules or ‘macro-molecules’are made up of much smaller molecules, can be of one or more chemical compounds. To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound. Alternatively, individual rings could be of different sizes and materials, and interlinked to represent a polymer from molecules of different compounds. 什么是高聚物?首先,他们是合成物和大分子,而且不同于低分子化合物,譬如说普通的盐。与低分子化合物不同的是,普通盐的分子量仅仅是58.5,而高聚物的分子量高于105,甚至大于106。这些大分子或“高分子”由许多小分子组成。小分子相互结合形成大分子,大分子能够是一种或多种化合物。举例说明,想象一组大小相同并由相同的材料制成的环。当这些环相互连接起来,可以把形成的链看成是具有同种分子量化合物组成的高聚物。另一方面,独特的环可以大小不同、材料不同,相连接后形成具有不同分子量化合物组成的聚合物。 This interlinking of many units has given the polymer its name, poly meaning ‘many’and mer meaning ‘part’(in Greek). As an example, a gaseous compound called butadiene, with a molecular weight of 54, combines nearly 4000 times and gives a polymer known as polybutadiene (a synthetic rubber) with about 200 000molecular weight. The low molecular weight compounds from which the polymers form are known as monomers. The picture is simply as follows: 许多单元相连接给予了聚合物一个名称,poly意味着“多、聚、重复”,mer意味着“链节、基体”(希腊语中)。例如:称为丁二烯的气态化合物,分子量为54,化合将近4000次,得到分子量大约为200000被称作聚丁二烯(合成橡胶)的高聚物。形成高聚物的低分子化合物称为单体。下面简单地描述一下形成过程: butadiene + butadiene + ???+ butadiene--→polybutadiene (4 000 time) 丁二烯+丁二烯+…+丁二烯——→聚丁二烯 (4000次) One can thus see how a substance (monomer) with as small a molecule weight as 54 grow to become a giant molecule (polymer) of (54×4 000≈)200 000 molecular weight. It is essentially the ‘giantness’of the size of the polymer molecule that makes its behavior different from that of a commonly known chemical compound such as benzene. Solid benzene, for instance, melts

资料:《安全工程专业英语(部分翻译)》

Unit 1 safety management system Accident causation models 事故致因理论 Safety management 安全管理Physical conditions 物质条件Machine guarding 机械保护装置House-keeping 工作场所管理 Top management 高层管理人员Human errors 人因失误 Accident-proneness models 事故倾向模型Munitions factory 军工厂 Causal factors 起因 Risking taking 冒险行为 Corporate culture 企业文化 Loss prevention 损失预防 Process industry 制造工业 Hazard control 危险控制 Intensive study 广泛研究Organizational performance 企业绩效Mutual trust 相互信任Safety officer 安全官员Safety committee 安全委员会Shop-floor 生产区Unionized company 集团公司Seniority 资历、工龄Local culture 当地文化Absenteeism rate 缺勤率Power relations 权力关系 Status review 状态审查 Lower-level management 低层管理者Business performance 组织绩效Most senior executive 高级主管Supervisory level 监督层Safety principle 安全规则 Wall-board 公告栏Implement plan 执行计划 Hazard identification 危险辨识Safety performance 安全性能 One comprehensive definition for an organizational culture has been presented by Schein who has said the organizational culture is “a pattern of basic assumptions –invented, discovered, or developed by a given group as it learns to cope with its problems of external adaptation and internal integration –that has worked well enough to be considered valid and, therefore, to be taught to new members as the correct way to perceive, think, and feel in relation to those problems” 译文:Schein给出了组织文化的广泛定义,他认为组织文化是由若干基本假设组成的一种模式,这些假设是由某个特定团体在处理外部适应问题与内部整合问题的过程中发明、发现或完善的。由于以这种模式工作的有效性得到了认可,因此将它作为一种正确的方法传授给新成员,让他们以此来认识、思考和解决问题[指适应外部与整合内部的过程中的问题]。 The safety culture of an organization is the product of individual and group values, attitudes, perceptions, competencies, and patterns of behavior that determine the commitment t o, and the style and proficiency of , an organization’s health and safety management. 译文:组织的安全文化由以下几项内容组成:个人和群体的价值观、态度、观念、能力和行为方式。这种行为方式决定了个人或团体对组织健康安全管理的责任,以及组织健康安全管理的形式和熟练程度。

工业工程专业英语1-3单元翻译

Professional English for Industrial Engineering Chapter1 Unit3翻译 姓名: 专业:工业工程 班级: 学号: 完成日期:2015-10-31

Chapter 1 Unit 3 Academic Disciplines of Industrial Engineering 五大主要工程学科和它们的发展 在美国,有五个主要工程学科(土木、化学、电工、工业、机械),它们是早在第一次世界大战时就出现的工程分支学科。这些进步是世界范围内发生的工业革命的一部分,并且在技术革命的开始阶段仍在发生。 随着第二次世界大战的发展导致了其他工程学科的发展,比如核工程,电子工程,航空工程,甚至是电脑工程。太空时代导致了航空工程的发展。最近对环境的关注使得环境工程和生态工程也得到了发展。这些更新的工程学科经常被认为是专长学科包含“五大”学科,即土木,化学,电工,工业,和机械工程里的一种或多种。 和美国的情况不同,工业工程在中国属于第一层级管理科学和工程学科下面的第二级别的学科。 IE学科的开端 学科后来演变成工业工程学科是最初在机械工程系被作为特殊课程教的。首个工业工程的分部在1908年的宾夕法尼亚州大学和雪城大学被建立。(在宾夕法尼亚州的项目是短期存在的,但是它在1925年又重建了)一个在普渡大学的机械工程的IE选科在1911年被建立。一个更完整的工业工程学院项目的历史可能在资料中被找到。 在机械工程部有一个IE选科的实践是主要的模式直到第二次世界大战的结束,并且分离出来的IE部在整个上个世纪里的文理学院和综合大学里被建立。 早在第二次世界大战的时候,在工业工程方面,只有很少的毕业生水平的研究。一旦分开的学部建立之后,学士和博士级别的项目开始出现。 现代IE的教育—分支学科 今天,与过去相比,工业工程对于不同的人来说意味着不同的东西。实际上,一个发展一个突出的现代工业工程的方法是通过获得在它的分支学科和它怎么联系到其他领域的理解。如果在分支学科和工业工程相关联的领域之间有清楚的

自动化专业英语_考试版的文章翻译

UNIT 1 A 电路 电路或电网络由以某种方式连接的电阻器、电感器和电容器等元件组成。如果网络不包含能源,如 电池或发电机,那么就被称作无源网络。换句话说,如果存在一个或多个能源,那么组合的结果为有源网络。在研究电网络的特性时,我们感兴趣的是确定电路中的电压和电流。因为网络由无源电路元件组成,所以必须首先定义这些元件的电特性. 就电阻来说,电压-电流的关系由欧姆定律给出,欧姆定律指出:电阻两端的电压等于电阻上流过的电流乘以电阻值。在数学上表达为: u=iR (1-1A-1)式中 u=电压,伏特;i =电流,安培;R = 电阻,欧姆。 纯电感电压由法拉第定律定义,法拉第定律指出:电感两端的电压正比于流过电感的电流随时间的 变化率。因此可得到:U=Ldi/dt 式中 di/dt = 电流变化率,安培/秒; L = 感应系数,享利。 电容两端建立的电压正比于电容两极板上积累的电荷q 。因为电荷的积累可表示为电荷增量dq的和或积分,因此得到的等式为 u= ,式中电容量C是与电压和电荷相关的比例常数。由定义可知,电流等于电荷随时间的变化率,可表示为i = dq/dt。因此电荷增量dq 等于电流乘以相应的时间增量,或dq = i dt,那么等式 (1-1A-3) 可写为式中 C = 电容量,法拉。 归纳式(1-1A-1)、(1-1A-2) 和 (1-1A-4)描述的三种无源电路元件如图1-1A-1所示。注意,图中电流的参考方向为惯用的参考方向,因此流过每一个元件的电流与电压降的方向一致。 有源电气元件涉及将其它能量转换为电能,例如,电池中的电能来自其储存的化学能,发电机的电能是旋转电枢机械能转换的结果。 有源电气元件存在两种基本形式:电压源和电流源。其理想状态为:电压源两端的电压恒定,与从 电压源中流出的电流无关。因为负载变化时电压基本恒定,所以上述电池和发电机被认为是电压源。另一方面,电流源产生电流,电流的大小与电源连接的负载无关。虽然电流源在实际中不常见,但其概念的确在表示借助于等值电路的放大器件,比如晶体管中具有广泛应用。电压源和电流源的符号表示如图1-1A-2所示。 分析电网络的一般方法是网孔分析法或回路分析法。应用于此方法的基本定律是基尔霍夫第一定律,基尔霍夫第一定律指出:一个闭合回路中的电压代数和为0,换句话说,任一闭合回路中的电压升等于电压降。网孔分析指的是:假设有一个电流——即所谓的回路电流——流过电路中的每一个回路,求每一个回路电压降的代数和,并令其为零。 考虑图1-1A-3a 所示的电路,其由串联到电压源上的电感和电阻组成,假设回路电流i ,那么回路总的电压降为因为在假定的电流方向上,输入电压代表电压升的方向,所以输电压在(1-1A-5)式中为负。因为电流方向是电压下降的方向,所以每一个无源元件的压降为正。利用电阻和电感压降公式,可得等式(1-1A-6)是电路电流的微分方程式。 或许在电路中,人们感兴趣的变量是电感电压而不是电感电流。正如图1-1A-1指出的用积分代替式(1-1A-6)中的i,可得1-1A-7 UNIT 3 A 逻辑变量与触发器

高分子专业英语课文翻译

高分子专业英语课文翻译 高分子专业英语选讲课文翻译资料 A 高分子化学和高分子物理 UNIT 1 What are Polymer? 第一单元什么是高聚物, What are polymers? For one thing, they are complex and giant molecules and 什么是高聚物, 首先,他们是合成物和大分子,而且不同于低分子化合物,譬are different from low molecular weight compounds like, say, common salt. To 如说普通的盐。 contrast the difference, the molecular weight of common salt is only 58.5, while 与低分子化合物不同的是,普通盐的分子量仅仅是58.5, that of a polymer can be as high as several hundred thousand, even more than thousand 而高聚物的分子量高于105,甚至大于106。 thousands. These big molecules or ‘macro-molecules’ are made up of much smaller 这些大分子或“高分子”由许多小分子组成, 小分子相互结合形成大分子,molecules, can be of one or more chemical compounds. To illustrate, imagine that 大分子能够是一种或多种化合物。举例说明, a set of rings has the same size and is made of the same material. When these things 想象一组大小相同并由相同的材料制成的环。当这些环相互连接are

哈工大工业工程专业英语翻译

《工业工程专业英语》 课文翻译 专业:工业工程 学号:11208401 姓名: 指导教师:赵,, 2014年12月

4.2 ERP系统的发展过程 现在,ERP系统无处不在,不仅应用在大型业务中,目前还由运营商们改良后应用在中小企业中。我们需要通过理解ERP系统及其当前体系结构的历史和发展来说明其发展变迁的成果。ERP的优点和缺点会影响它对市场的渗透,系统供应商已经为ERP的推动做好了市场定位和总体策略方面的准备。ERP系统在新的世纪中的应用和发展将依赖于其对客户关系管理、供应链管理一起其他拓展功能的扩充,还有与网络应用的结合。 简介 由微电子、电脑硬件和软件系统驱动的信息和交流的前所未有的增长影响了各种组织的电脑应用的方方面面。同时,公司环境与职能部门日益结合,需要为决策提供越来越多的内部功能数据流,包括及时有效的产品部件的供给、库存管理、清算账目、人力资源以及产品和服务分配等。在这样的条件下,组织管理者需要一个有效的信息系统来降低成本并优化物流,从而提高竞争力。无论是大企业还是中小企业,大家一致认为在复杂的全球化竞争中,及时获得正确的信息的能力能够给企业带来巨大的回报。 从19世纪80年代末到90年代初开始的新的软件系统作为企业资源规划应用在复杂的大型商业企业中从而在工业界中被人们所周知。这种复杂而昂贵,强力而专有的系统供不应求,而且需要根据企业的需求量身定制。很多情况下,ERP实施人员要企业重新设计他们的商业流程来调节软件模型中的物流,从而得到整个企业的数据流。与旧的、传统的自我内部设计的企业专门系统不同,这种软件解决方案结合了多种模型的商业附加包,在需要的时候可以作为附件添加到系统中或者从中删除。 电脑性能的显著提高以及网络给ERP的供应商和设计者们带来的前所未有的挑战,打破了企业与客户定制的隔阂,还包含超出企业内部网络的合作,外部系统需要通过网络来无缝连接。供应商已经许诺了许多的附加功能包,他们中的一些人已经在市场上表现出对这些挑战的接受态度。将产品不断再设计以及在ERP市场中推出新产品和方案是一个永不终止的过程。ERP运营商和客户以及认识到了将其附件按照开放的原则设计,提供可互换的模型,以及容许更简单的定制和客户交流的必要性。 ERP系统定义 企业资源规划系统或企业系统是业务管理软件系统目前,包括模块配套功能区,如计划,制造,销售,市场营销,分销,会计,金融,人力资源管理,项目管理,库存管理,服务,维修,运输和电子商务,架构软件便于模块的透明集成,提供企业内的所有功能之间信息。在运输和电子商务。该架构软件便于模块的透明集成,提供数据流包括良好的企业内的所有功能之间的信息以及与合作公司与通过更换或重新设计实现一个单一的集成系统,其大多是不兼容的传统信息系统。美国生产与库存管理协会(2001)这样定义了ERP系统:“针对物资资源管理、人力资源管理、财务资源管理、信息资源管理集成一体化的企业管理软件。”我们从出版物中摘录了几种定义来更好的解释这个概念:“ERP包含了一个商业软件包,它可以通过企业的财务、清算、人力资源、供应链和客户信息来使数据流无缝结合”(Davenport,1998)。“ERP是将一个组织中的财务和其他信息以及基于信息的流程整合在一起的信息配置系统。”(K&VH,2000)。“一个数据库、一个应用和一个贯穿整个企业的统一界面”(Tadjer,1998)。“ERP系统是为了运作一个组织的业务方便的集成和实时计划、生产,以及客户反馈而设计的基于电脑的系统(OLeary,2001)”。 ERP系统的发展

高分子材料工程专业英语翻译(最新修正稿)

UNIT 1 What Are Polymers? 第一单元什么是高聚物? 什么是高聚物?首先,他们是络合物和大分子,而且不同于低分子化合物,譬如说普通的盐。与低分子化合物不同的是,普通盐的分子量仅仅是58.5,而高聚物的分子量高于105,甚至大于106。这些大分子或“高分子”由许多小分子组成。小分子相互结合形成大分子,大分子能够是一种或多种化合物。举例说明,想象一组大小相同并由相同的材料制成的环。当这些环相互连接起来,可以把形成的链看成是具有同种(分子量)化合物组成的高聚物。另一方面,独立的环可以大小不同、材料不同,相连接后形成具有不同(分子量)化合物组成的聚合物。 许多单元相连接给予了聚合物一个名称,poly意味着“多、聚、重复”,mer意味着“链节、基体”(希腊语中)。例如:称为丁二烯的气态化合物,分子量为54,化合将近4000次,得到分子量大约为200000被称作聚丁二烯(合成橡胶)的高聚物。形成高聚物的低分子化合物称为单体。下面简单地描述一下形成过程: 丁二烯+丁二烯+…+丁二烯——→聚丁二烯 (4000次) 因而能够看到分子量仅为54的小分子物质(单体)如何逐渐形成分子量为200000的大分子(高聚物)。实质上,正是由于聚合物的巨大的分子尺寸才使其性能不同于像苯这样的一般化合物(的性能)。1例如,固态苯,在5.5℃熔融成液态苯,进一步加热,煮沸成气态苯。与这类简单化合物明确的行为相比,像聚乙烯这样的聚合物不能在某一特定的温度快速地熔融成纯净的液体。而聚合物变得越来越软,最终,变成十分粘稠的聚合物熔融体。将这种热而粘稠的聚合物熔融体进一步加热,不会转变成各种气体,但它不再是聚乙烯(如图1.1)。 固态苯——→液态苯——→气态苯 加热,5.5℃加热,80℃ 固体聚乙烯——→熔化的聚乙烯——→各种分解产物-但不是聚乙烯 加热加热 图1.1 低分子量化合物(苯)和聚合物(聚乙烯)受热后的不同行为发现另一种不同的聚合物行为和低分子量化合物行为是关于溶解过程。例如,让我们研究一下,将氯化钠慢慢地添加到固定量的水中。盐,代表一种低分子量化合物,在水中达到点(叫饱和点)溶解,但,此后,进一步添加盐不进入溶液中却沉到底部而保持原有的固体状态。饱和盐溶液的粘度与水的粘度不是十分不同,但是,如果我们用聚合物替代,譬如说,将聚乙烯醇添加到固定量的水中,聚合物不是马上进入到溶液中。聚乙烯醇颗粒首先吸水溶胀,发生形变,经过很长的时间以后,(聚乙烯醇分子)进入到溶液中。2同样地,我们可以将大量的聚合物加入到同样量的水中,不存在饱和点。将越来越多的聚合物加入水中,认为聚合物溶解的时间明显地增加,最终呈现柔软像面团一样粘稠的混合物。另一个特点是,在水中聚乙烯醇不会像过量的氯化钠在饱和盐溶液中那样能保持其初始的粉末状态。3总之,我们可以讲(1)聚乙烯醇的溶解需要很长时间,(2)不存在饱和点,(3)粘度的增加是典 型聚合物溶于溶液中的特性,这些特性主要归因于聚合物大分子的尺寸。 如图1.2说明了低分子量化合物和聚合物的溶解行为。 氯化钠晶体加入到水中→晶体进入到溶液中.溶液的粘度不是十分不同于充分搅拌 水的粘度→形成饱和溶液.剩余的晶体维持不溶解状态.加入更多的晶体并搅拌氯化钠的溶 解 聚乙烯醇碎片加入到水中→碎片开始溶胀→碎片慢慢地进入到溶液中允许维持现状 充分搅拌→形成粘稠的聚合物溶液.溶液粘度十分高于水的粘度继续搅拌聚合物的溶解

资料《安全工程专业英语部分翻译》

Unit 1safety management system Accident causation models ?事故致因理论 Safety management 安全管理 Physicalconditions ?物质条件 Machineguarding?机械保护装置 House—keeping工作场所管理 Topmanagement 高层管理人员Human errors人因失误 Accident-proneness models 事故倾向模型 Munitions factory?军工厂Causal factors?起因 Riskingtaking?冒险行为 Corporateculture 企业文化 Lossprevention 损失预防 Process industry?制造工业 Hazard control 危险控制 Intensive study广泛研究 Organizationalperformance 企业绩效 Mutual trust 相互信任Safetyofficer?安全官员 Safety committee 安全委员会 Shop-floor?生产区Unionized company 集团公司 Seniority?资历、工龄Local culture当地文化Absenteeism rate?缺勤率Power relations?权力关系 Status review 状态审查Lower—level management低层管理者 Business performance?组织绩效 Most seniorexecutive 高级主管Supervisory level监督层 Safety principle?安全规则 Wall—board?公告栏 Implement plan?执行计划 Hazardidentification 危险辨识 Safety performance 安全性能 One comprehensive definition for an organizational culture has been presentedbySchein who has said theorganizational cultureis“a pattern of basic assumptions–invented, discovere d,or developedby agiven group as itlearns to cope with its problems of external adaptation and internal integration– that h as worked well enoughto be consideredvalidand,therefore, to betaught to new membersas the correct way to perceive, thin k,and feel in relation to thoseproblems” 译文:Schein给出了组织文化的广泛定义,他认为组织文化是由若干基本假设组成的一种模式,这些假设是由某个特定团体在处理外部适应问题与内部整合问题的过程中发明、发现或完善的.由于以这种模式工作的有效性得到了认可,因此将它作为一种正确的方法传授给新成员,让他们以此来认识、思考和解决问题[指适应外部与整合内部的过程中的问题]。 The safety culture ofan organization isthe product of individual and group values,attitudes, perceptions, competencies, and pa tternsofbehavior that determine the commitment to, and the style and proficiency of,an organization’shealthandsafety management.

周跃进工业工程专业英语翻译-全十章---副本

第一章 IE中的角色 工业工程是新兴的经典和新颖的将计算解决复杂和系统性的问题,在今天的高度科技世界职业之一。,特别是在中国快速发展的经济和其作为世界制造业中心的演技,为IE浏览器的需求将增加,并不断扩大和迫切。 生产系统或服务系统,包括输入,转换和输出。通过改造,增加值的增加,系统的效率和效益都有所提高。转化过程中所使用的技术和管理科学以及它们的组合依靠。 管理生产系统的服务体系,是一个具有挑战性和复杂的,行为科学,计算机和信息科学,经济,以及大量的主题有关的基本原则和技术,生产和服务系统的技术。 对于IE毕业生的需求 工业工程课程设计准备的学生,以满足未来中国的经济和和谐社会建设的挑战。许多即毕业生(IES),事实上,设计和运行现代制造系统和设施。其他选择从事服务活动,如健康,?ìcare交付,金融,物流,交通,教育,公共管理,或咨询等。 为IE毕业生的需求比较旺盛,每年增长。事实上,对于非法入境者的需求大大超过供给。这种需求/供给不平衡是为IE大于其他任何工程或科学学科,并预计在未来多年存在。因此,over165大学或学院于2006年在中国开设了IE浏览器程序。 教科书的目标 这本教科书的主要目的是引入系统化的理论和先进的技术和方法,工业工程,以及他们的英语表达有关科目。教科书的另一个目的是加强和改进学生,AOS与工业工程专业英语文献的阅读和理解能力。 工程与科学 怎么这两个词,?úindustrial,?ùand,?úengineering,?ùget相结合,形成长期,?úindustrial工程,非盟是什么?工业工程和其他工程学科之间的关系,企业管理,社会科学?为了了解工业工程的作用,在今天,AOS经济和知识为基础的的时代,它是有利于学习,希望在IE的演变历史的发展,有许多半途而废写历史发展的工程。治疗本单位是短暂的,因为我们的利益,在审查工程发展的意义,尤其是作为一个专业工业工程的,更完整的历史参考。工程与科学发展并行,相辅相成的方式,虽然他们是电机始终以同样的速度,而科学是有关基本知识的追求,工程与科学知识的应用关注问题的解决方案,并,?úbetter生活的追求,?ù.Obviously,知识不能被应用,直到它被发现的,一经发现,将很快投入使用,在努力解决问题,工程在新知识的地方,提供反馈,以科学因此,科学和工程工作在手的手。 工程应用 - 工具 虽然“科学”和“工程”各有特色,为不同学科,在某些情况下,?úscientist,非盟和?úengineer,非盟可能是同一个人。这是在更早的时候,尤其是当有很少沟通的基本知识的手段。发现知识的人也把它用。 当然,我们也想到如此出色的成绩,在埃及的金字塔,中国长城,罗马的建设项目,等等,当我们回顾早期的工程成就。这些都涉及一个令人印象深刻的应用程序的基本知识。 正如根本,但是,不作为众所周知的成就。斜面,弓,螺旋状,水车,帆,简单的杠杆,以及许多其他方面的发展都非常希望在工程师,AO努力提供更好的生活。 工程的基础 几乎所有的工程发展到1800年之前与物理现象:如克服摩擦,起重,储存,搬运,构造,紧固后的发展,关注与化学和分子现象:如电力,材料,热加工工艺性能,燃烧,和其他的化学过程。 几乎所有的工程发展的基本原则是在数学方面取得的进展。,准确地测量距离,角度,重量和时间的程序进行了细化,实现了更大的成就。

电气自动化专业英语翻译

电气自动化专业英语(翻译1-3) 第一部分:电子技术 第一章电子测量仪表 电子技术人员使用许多不同类型的测量仪器。一些工作需要精确测量面另一些工作只需粗略估计。有些仪器被使用仅仅是确定线路是否完整。最常用的测量测试仪表有:电压测试仪,电压表,欧姆表,连续性测试仪,兆欧表,瓦特表还有瓦特小时表。 所有测量电值的表基本上都是电流表。他们测量或是比较通过他们的电流值。这些仪表可以被校准并且设计了不同的量程,以便读出期望的数值。 1.1安全预防 仪表的正确连接对于使用者的安全预防和仪表的正确维护是非常重要的。仪表的结构和操作的基本知识能帮助使用者按安全工作程序来对他们正确连接和维护。许多仪表被设计的只能用于直流或只能用于交流,而其它的则可交替使用。注意:每种仪表只能用来测量符合设计要求的电流类型。如果用在不正确的电流类型中可能对仪表有危险并且可能对使用者引起伤害。 许多仪表被设计成只能测量很低的数值,还有些能测量非常大的数值。 警告:仪表不允许超过它的额定最大值。不允许被测的实际数值超过仪表最大允许值的要求再强调也不过分。超过最大值对指针有伤害,有害于正确校准,并且在某种情况下能引起仪表爆炸造成对作用者的伤害。许多仪表装备了过载保护。然而,通常情况下电流大于仪表设计的限定仍然是危险的。 1.3测量仪器的使用 电压表是设计来测量电路的电压或者通过元器件的压降。电压表必须与被测量的电路或元器件并联。 1.3.1压力检验计 交-直流电压检验计是一种相当粗糙但对电工来说很有用的仪器。这种仪器指示电压的近似值。更常见类型指示的电压值如下:AC,110,220,440,550V,DC,125,250,600V。许多这种仪器也指示直流电的极性。那就是说(i.e=that is)电路中的导体是阳性(正)的还是阴性(负)。 电压检验计通常用来检验公共电压,识别接地导体,检查被炸毁的保险丝,区分AC和DC。电压检验计很小很坚固,比一般的电压表容易携带和保存。图1。31。4描述了用电压检验计检查保险丝的用法。 为了确定电路或系统中的导体接地,把测试仪连接在导体和已建立的地之间。如果测试仪指示了一个

安全工程专业英语Unit1-9翻译

安全工程专业英语 Unit1 1. Because of the very rapid changes in these jobs and professions, it is hard for students to learn about future job opportunities. It is even more difficult to know about the type of preparation that is needed for a particular profession-or the qualities and traits that might help individuals succeed in it. 由于这些工作和职业的飞速变更,其变化之快使得学生们很难了解未来有什么样的工作机会,更不知道为未来的具体职业生涯做出怎样的准备,也就是说学生们很难知道掌握何种知识、具备何种能力才能成功适应未来的社会。 2. The purpose of this article is to provide in depth information about the safety profession that should help students considering a career in this challenging and rewarding field. 这篇文章将提供较为深入的安全专业方面的具体信息,它应该能够为安全专业的学生们在这个充满挑战也蕴含着发展机遇的职业中获得良好的发展而提供帮助。 3. While these efforts became more sophisticated and widespread during the twentieth century, real progress on a wide front did not occur in the U.S. until after Word War Ⅱ. 尽管这些专业手段在20世纪已经发展的较为成熟,也具有一定的广泛适应性,但在美国,这些都是第二次世界大战以后才取得的突破性进展。 4. This legislation was important because it stressed the control of workplace hazards. This, in turn, defined a clear area of practice for the previously loosely organized safety profession. Other legislation passed during the next twenty years has increased the scope of safety practice into areas of environmental protection, product safety, hazardous materials management and designing safety into vehicles, highways, process plants and buildings. 这部法律很重要,因为它强调工作场所的危险控制,同时这部法律也为以前不成体系的安全业务划定了工作范围。此后20年中通过的一

工业工程专业英语第三章翻译

《专业英语》课程论文 (工业工程11级) 指导教师:李发权 小组成员 姓名:学号:刘凯311102020215 刘雪涛311102020216 马文杰311102020217 乔茂康311102020218 2014年11月23日

Manufacturing Systems Unit1 Introduction To Manufacturing Systems In this chapter, we consider how automation and material handing technologies are synthesized create manufacturing systems. We define a manufacturing system to be a collection of integrated equipment and human resources, whose function is perform one or more processing and/or assembly operations on a starting raw material part, or set parts. The integrated equipment includes production machines and tools, material handling and work positioning devices, and computer systems. Human resources are required either full time or periodically to keep the system running. The manufacturing system is where the value-added work is accomplished on the part or product. The position of the manufacturing system in the larger production system is shown as Figure. 3.1 Examples of manufacturing systems include : ●One worker tending one machine, which operates on semi-automatic cycle ● A cluster of semi-automated assembly machine, attended by one worker ● A full automated assembly machine, periodically attended by a human worker ● A group of automated machines working on automatic cycles to produce a family of similar parts ● A team of workers performing assembly operations on a production line Components of a Manufacturing system A manufacturing system consists of several components. In a given system, these components usually include: 1)production machines plus tools, fixtures, and other related hardware; 2)material handling system ; 3)computer systems to coordinate and/or control the above components ; 4)human workers Production Machines In virtually all modern manufacturing systems, most of the actual processing or assembly work is accomplished by machines or with the aid of tools. The machines can be classified as 1) manually operate , 2) semi-automated ,or 3)fully automated , Manually operated machines are directed or supervised by a human worker. The machine provides the power for the operation and the worker provides the control. Conventional machine tools (e. g ,lathes , milling machines ,drill presses ) fit into this category . The worker must be at the machine continuously. In manufacturing systems, we use the term workstation to refer to a location in the factory where some well-defined task operation is accomplished by an automated machine , a worker-and-machine combination , or a worker use hang tools/or portable powered tools. In the last there no definable production machine at the location . Many assembly tasks are in the category . A given manufacturing system may consist of one or more workstations. A system with multiple stations is called a production line , or assembly line , or machine cell ,or other name ,depending on its configuration and function .

相关文档
相关文档 最新文档