材料学院专业外语试题.doc

2007-2008学年第一学期末考试试题（A卷） 课程名称：FUNDAMENTALS OF MATERIALS SCIENCE AND ENGINEERING一、填空题（20分）每空0.5分1The discipline of materials scienceinvolvesIn contrast, materials engineering is .2 金属材料的晶体结构主要包括: ,.3 物质中原子之间相互作用起源于原子核和电子间交互作用，根据电子围绕原子的分布方式，可以将这些作用力分为：,.4 高分子材料的基本结构包括:,.5 Forming techniques of metallic materials common include,and ,.6 Hardness of materials is measured according these methods,.7 POLYMER ADDITIVES applied in polymer materials common includes,and,.8 根据材料磁化率，可以把材料的磁性大致分为五类,.10 Three different forming methods are used to fabricate glass products:, and.11 自由基聚合方法是指，聚合过程包括三步,.12 FORMING TECHNIQUES FOR PLASTICS includes:,and.二、问答题（40分）每题8分1 Give the electron configurations for the following ions: Fe2+, Cu+, Br- and S-2.2 什么叫复合材料？复合材料的优点有哪些？ 3 什么叫导电率？导电的机理是什么？聚合物导电率为什么比较低？ 4 金属材料成型方法选择主要依赖于什么因素？试述聚合物成型加工特点与优势？ 5 Briefly cite the main differences between ionic, covalent, and metallic bonding?三、计算题（40分）每题10分1 The number-average degree of polymerization of a polypropylene is 6789, Compute the number-average molecular weight?2 Zirconium has an HCP crystal structure and a density of 6.51 g/cm3. What is the volume of its unit cell in cubic meters?3 An n-type semiconductor is known to have an electron concentration of 31018m-3.if the electron drift velocity is 100m/s in an electric field of 500V/m, calculate the conductivity of this material.4 The magnetization within a bar of some metal alloy is 3.2105 A/m at an H field of 50 A/m.Compute the following:(a) The magnetic susceptibility. (b) The permeability.A卷答案一、填空题（20分）每空0.5分1 investigating the relationships that exist between the structures and properties of materials. On the basis of these structureproperty correlations, designing or engineering the structure of a material to produce a predetermined set of properties.2体心立方（body-centered cubic）、面心立方(face-centered cubic)、密排六方(hexagonal close-packed)。 3 离子键(ionic bond)、共价键(covalent bond)、金属键(metallic bond)、分子间作用力(van der waal)和氢键(hydrogen bond)。 4 线形结构(linear)，支链结构(branched)，交联结构(crosslink)，网状结构(network)。 5 forging, rolling, extrusion, and drawing。 6 ROCKWELL, BRINELL, VICKERS 7 filler materials(填充物), plasticizers（增塑剂）, stabilizers（稳定剂）, colorants（着色剂）, and flame retardants（阻燃剂） 8 铁磁性（ferromagnetism），亚铁磁性(ferrimagnetism)，顺磁性(paramagnetism)，反铁磁性(diamagnetism)和抗铁磁性(antiferromagnetism)。9 pressing, blowing, and drawing 10 链引发(initiation)，链增长(propagation)和链终止(termination)。 11 compression（模压）, blow（吹塑）, and injection molding（注射）.二、问答题（40分）每题8分1 Solution: Fe2+ :1s2s2p3s3p63d6-2Cu+:1s2s2p3s3p63d10-2Br-:1s2s2p3s3p63d104s24p6-2S-2:1s2s2p3s3p6-22 Solution: A composite, in the present context, is a multiphase material that is artificiallymade, as opposed to one that occurs or forms naturally. In addition, the constituentphases must be chemically dissimilar and separated by a distinct interface（2分）.discussed; these include multiphasemetal alloys, ceramics, and polymers（1分）.(1) Most composites have been created to improve combinationsof mechanical characteristics such as stiffness, toughness, and ambient andhigh-temperature strength（1分） （2）example, aircraft engineers are increasingly searching for structural materials that have low densities(1分)(3) better propertycombinations are fashioned by the judicious combination of two or more distinctmaterials such as optical, electrical and magnetic materials and so on(2分)(4) Cost of some materials may be reduced by adding filler materials(1分)复合材料是有高分子、无机非金属或金属等多相材料通过人工组合而成的新型材料（2分），其基本是有连续相与分散相组成（1分）。 复合材料的优点： 1. 提高力学性能（1分） 2. 降低材料的密度（1分） 3. 获得可用的功能性材料，如耐高温，光电磁性材料（2分） 4. 降低成本（1分） 3 Solution:Sometimes, electrical conductivity _is used to specify the electrical character of amaterial（1分）. It is simply the reciprocal of the resistivity, and is indicative of the ease with which a material is capable of conducting an electric current（2分）.Within most solid materials a current arises fromthe flow of electrons, which is termed electronic conduction（2分）. In addition, for ionicmaterials a net motion of charged ions is possible that produces a current; such istermed ionic conduction（1分）. Most polymeric materials are poor conductors of electricity because ofthe unavailability of large numbers of free electrons to participate in the conductionprocess（1分）. The mechanism of electrical conduction in these materials is not wellunderstood, but it is felt that conduction in polymers of high purity is electronic（1分）.电导率是衡量材料电导能力的表观物理量（1分），它定义为单位电位下流过的每立方厘米材料的电流I（A）（2分）。 材料导电的原因是因为材料内部有可以移动的带电载流子（1分），因而材料的导电率大小是有载流子密度与载流子迁移率决定（1分），载流子可以是电子，也可以是正负离子（1分）。 聚合物的结构特点决定了，纯聚合物内部没有可以自由移动的电子，也不具有可以移动的离子（1分），另外载流电子也难以在聚合物链之间移动，所以大多数聚合物导电率是比较低的（1分）。 4要知识点： The methods chosen depend on severalfactors; the most important are the properties of the metal（1分）, the size and shape ofthe finished piece（1分）, and, of course, cost（1分）.Quite a variety of different techniques are employed in the forming of polymericmaterials.Fabrication of polymeric materials normally occurs at elevated temperaturesand often by the application of pressure（1分）.Molding is the most common method for forming plastic polymers. The severalmolding techniques used include compression, transfer, blow, injection, and extrusionmolding（2分）. For each, a finely pelletized or granulized plastic is forced, at anelevated temperature and by pressure, to flow into, fill, and assume the shape of amold cavity（2分）.主要依赖于以下几个因素： 1. 金属的延展性（1分） 2. 金属制品的尺寸与形状（1分） 3. 成本（1分） 聚合物成型是将各种形态的物料制成所需要形状制件的过程，成型方法很多，不仅具有铸造性，可焊性与切削加工性，还具有挤压，注射，压延，压制，中空吹塑，纺丝成型等方法。 聚合物加工特性（2分）聚合物材料的熔融特性，聚合物材料大多数成型操作有热软化或熔融的聚合物的流动和变形组成，所以熔融是聚合物材料加工的基本阶段，其温度要比金属低很多，容易操作。 聚合物流动特性（2分）。 主要经历：聚合物材料配制，聚合物材料成型与聚合物制品的后处理（1分）。 5 Solution:In covalent bonding stable electron configurations are assumed by the sharing of electrons between adjacent atoms.（1分） Ionic bonding is that Atoms of a metallic element easily give up their valence electrons to the nonmetallic atoms.（1分） Ionic bonding is termed nondirectional, that is, the magnitude of the bond is equal in all directions around an ion.（2分） The covalent bond is directional; that is, it is between specific atoms and may exist only in the direction between one atom and another that participates in the electron sharing.（2分） They may be though of as belonging to the metal as a whole, or forming a “sea of electrons” or an “electron cloud.”（2分） 离子键是有原子核释放出最外层的电子变成带正电荷的原子（正离子），与接收其放出的电子变成带负电荷的原子（负离子）相互作用之间的吸引作用所形成的一种结合（2分）。 随着正负离子相互充分接近，离子的电子云有相互排斥，当吸引和排斥作用相等时，则形成稳定的离子键，离子键没有方向性与饱和性（2分）。 共价键是两个原子共有最外层电子的键合（1分） 。 为了实现共用电子云的最大重叠，这种键合既有饱和性，又有方向性（2分）。 金属键是通过各原子都贡献出其价电子而变成外层电子层的金属正离子,所有贡献出来的价电子则在整个晶体内自由运动,这些价电子为所有金属原子共用.三、计算题（30分） 1 Solution:Mn=mn-4分 =426789-3分 =285138-3分 2 Solution:= (nA)/(VcNA)-4分 Vc=(nA)/ (NA)-3分 = (691.22)/ (6.516.0231023)-2分 =1.410-28m3-1分 3 Solution:ue=ud/=100m/s/500v/m=0.2m2s-1v-1.3分 4分 =310181.610-190.22分 =0.096(m)-11分 4 Solution:(a) Xm=M/H2分 =3.2105/50.1分 =64001分 (b) ur= Xm+1=6401.2分 U= uru0.2=64011.2510-6.1分 =810-3H/m.1分 2007-2008学年第一学期末考试试题（B卷） 一、填空题（20分）每空0.5分1 Each atom consists of a very small composed of and , which is encircled by moving .2 The disfigurement in materials includes: ， ， and according their outer properties. 3 The phenomena of , , and may be applied to thepassage of light through a transparent solid4 according to the type of atom in main chain of polymer, the polymer include the five type as shown following: ， , ， ， 。 5 Two common shaping techniques are utilized for forming clay-based compositions:? and .6 one way of classifying solid materials is according to the ease with which they conduct an electric current; within this classification, there are three groupings: , , and .7 Two of the most important of absorption are and 。8 semiconductor include： and according the conducted mechanism. And extrinsic semiconductors include： ， 。 9 according the composition of materials, material include: ， ， ， 。 10 according the process of polymerization, the polymerization include ， ， ， 。 11 according the wavelength, electromagnetism radiation include ， ， ， ， 。 得分 二、问答题（40分）每题8分1 Offer an explanation as to why covalently bonded materials are generally less densethan ionically or metallically bonded ones2 Why lots of materials appear color?3 Briefly describe the phenomenon of passivity. ?Name two common types of alloy that passivate?4 What is the distinction between matrix and dispersed phases in a composite material? 5 what characteristic are the polymer composition and structure and briefly describe the process of polymer materials. 得分 三、计算题（40分）每题10分1 The magnetization within a bar of some metal alloy is 3.2105 A/m at an H field of 50 A/m.Compute the magenetic flux density within the materials.2 A specimen of a 4340 steel alloy having a plane strain fracture toughness of 40MPa/m-1/2 is exposed to a stress of 800Mpa. Will this specimen experience fracture if it is known that the largest surface crack is 0.6mm long? Why or why not? Assume that the parameter Y has a value of 1.0. 3 A relatively large plate of a glass is subjected to a tensile stress of 30 MPa. If the maximum length of a surface flaw that is possible 9 m without fracture, compute the modulus of elasticity of this glass, the specific surface energy and 0.3 J/m2.4 A brass rod is to be used in an application requiring its ends to be held rigid. If the rod is stress free at room temperature 20oC, the maximum temperature to which the rod may be heated without exceeding a compressive stress of 154 MPa is 150 oC. ?Compute a modulus of elasticity of brass. the linear coefficient of thermal expansion is 20.0 106 (oC)-1.B卷答案一、填空题（20分）每空0.5分1 nucleus，protons，neutrons及electrons。 2 dot disfigurement，line disfigurement，face disfigurement，body disfigurement。 3 absorption，reflection，transmission。 4 carbon chain，miscellaneous chain，element chain，inorganic chain5 hydroplastic forming, slip casting6 conductors, semiconductor, semiconductor 7 electronic polarization , electronic polarization 8 Intrinsic semiconductors extrinsic semiconductorsn-TYPE EXTRINSIC SEMICONDUCTION p-TYPE EXTRINSIC SEMICONDUCTION9 metallic materials，polymer materials，ceramic materials及composite materials。 10 Intrinsic polymerization，solution polymerization，latex polymerization，suspend polymerization。 11 x-rays, ultraviolet, visible, infrared, radio waves 二、问答题（40分）每题8分1 In covalent bonding stable electron configurations are assumed by the sharing of electrons between adjacent atoms.（1分） Ionic bonding is that Atoms of a metallic element easily give up their valence electrons to the nonmetallic atoms.（1分） Ionic bonding is termed nondirectional, that is, the magnitude of the bond is equal in all directions around an ion.（2分） The covalent bond is directional; that is, it is between specific atoms and may exist only in the direction between one atom and another that participates in the electron sharing.（2分） So, a unit cell for this crystal structure is generated from an Close-Packed arrangementof anions with others cations.（2分） 离子键是有原子核释放出最外层的电子变成带正电荷的原子（正离子），与接收其放出的电子变成带负电荷的原子（负离子）相互作用之间的吸引作用所形成的一种结合（2分）。 随着正负离子相互充分接近，离子的电子云有相互排斥，当吸引和排斥作用相等时，则形成稳定的离子键，离子键没有方向性与饱和性（2分）。 共价键是两个原子共有最外层电子的键合（1分） 。 为了实现共用电子云的最大重叠，这种键合既有饱和性，又有方向性（2分）。 所以这种价键集合的晶体结构原子间排列比其他晶体要松散，密度要小（1分）。 2 The color discerned is a result of the combination of wavelengths that are transmitted and reflected. 1分 Metals are transparent to high frequency(x- and -ray) radiation. Since metals are opaque and highly reflective, the perceived color is determined by the wavelength distribution of the radiation that is reflected and not absorbed.By virtue of their electron energy band structures, nonmetallic materials may be transparent to visible light. Therefore, in addition to reflection and absorption, refraction and transmission phenomena also need to be considerthe color discerned is a result of thecombination of wavelengths that are transmitted. If absorption is uniform for allvisible wavelengths, the material appears colorless;材料的颜色主要是来自于材料的透射与反射过程.金属的反射是有吸收与再发射综合造成的,发射过程的效率与入射线的频率有关.金属的白色就是来源于发射率的频率依赖性,而部分金属为橘红色与黄色特征,是来源于其他可见光被吸收.非金属可能是澄清的,也可能带颜色,这是选择吸收,选择反射的结果.大多数非金属都对红外线有一定程度的吸收.而部分非金属可见光都被吸收,因而是深灰色或暗淡的金属光泽.聚合物材料多是无色的，包括从高透明的到不透明的,透明度的损失起因于材料内部的折射指数不均匀产生的光散射性.,这些不均匀性是来之于材料内部无定形区和结晶中密度的差异.3 Some normally active metals and alloys, under particular environmental conditions,lose their chemical reactivity and become extremely inert. This phenomenon, termedpassivity, is displayed by chromium, iron, nickel, titanium, and many of their alloys.It is felt that this passive behavior results from the formation of a highly adherentand very thin oxide film on the metal surface, which serves as a protective barrierto further corrosion.Stainless steels are highly resistant to corrosion in a ratherwide variety of atmospheres as a result of passivation. They contain at least 11%chromium which, as a solid-solution alloying element in iron, minimizes the formationof rust; instead, a protective surface film forms in oxidizing atmospheres.Aluminum is highly corrosion resistant in many environ ments because it also passivates. If damaged, the protective film normally reformsvery rapidly.一些金属材料或合金材料在一些特殊环境中会失去化学活性,这种现象我们称之为金属材料的钝化,通常存在于铁,铬,钛,镍等金属中.这种钝化现象的产生主要是来之于这些金属表面形成了化学活性很低的氧化层,阻碍了金属进一步因为化学反应而腐蚀.钢就是一种能在一些特殊环境中也能保持不被腐蚀,这就是因为钝化现象的存在,比较好的耐气候的腐蚀性.这是因为其内含有11%的铬元素,在铁中形成固溶体,从而减少形成铁锈的机会,而是形成保护的氧化层.同样铝元素也是因为此钝化现象的存在,而具有良好的耐腐蚀性.4 Many composite materials are composed of just two phases; one is termed thematrix, which is continuous and surrounds the other phase, often called the dispersedphase. The properties of composites are a function of the properties of the constituent phases, their relative amounts, and the geometry of the dispersed phase.Dispersed phase geometry in this context means the shape of the particles and the particle size, distribution, and orientation;复合材料是有基体与增强材料两组元所组成.复合材料的结构形式丰富多彩,具有很好的可设计性.结构形式的变化主要取决于增强体或功能体(分散相)的结构与形态及在基体(连续相)中的分布或排布情况，另外就取决于基体的结构与性能.增强体主要有球型颗粒,微小片状,短纤维,连续长纤维等.它们与基体构成的复合材料主要结构有:无规分散增强结构,连续长纤维单向增强结构,层合结构.5These long molecules are composed of structural entities called mer units, whichare successively repeated along the chain. Mer originates from the Greek wordmeros, which means part; the term polymer was coined to mean many mers.The large macromolecules of the commercially useful polymers must be synthesizedfrom substances having smaller molecules in a process termed polymerizatio