【正文】 desirable 8 ，并主要受到航空和能源工業(yè)的推動。發(fā)達(dá)地區(qū)的人均能量使用量是不發(fā)達(dá)地區(qū)人均能量使用量的九倍以上。6． Test specimenstatic loadingforcenormal axisEngineering straincritical stressyield strength stress areaStressstrain curve below room temperature generally cause an increase in strength properties of metallic alloys。，一般多測幾次以得到力學(xué)性能，報(bào)導(dǎo)的數(shù)值一般是平均值或者計(jì)算的統(tǒng)計(jì)最小值。4． 某些鐵磁性材料，特別是一些粉末狀或夾層鐵，鋼或鎳合金的相對導(dǎo)磁率可高達(dá)1000000。5． Microstructuremacrostructure 1Chemical reactionatomic weight Balanced electrical chargepositively charged proton atoms form thousands of different substances ranging from the air we breathe to the metal used to support tall buildings, 7．The facts suggests that metallic atoms are held together bu strong which includes features that cannot be seen with the naked eye,but using a includes features that can be seen with the naked atomic weight is the sum of proton number and neutron number in the 4 1． 當(dāng)密度小于水的密度時(shí)，物體將漂浮在水面上，當(dāng)密度大于水的密度時(shí)，物體會沉降。微結(jié)構(gòu)和宏觀結(jié)構(gòu)雖也能影響這些性能但是他們主要影響力學(xué)性能和化學(xué)反應(yīng)速率。；反之，當(dāng)它們膨脹和收縮時(shí)，他們也能產(chǎn)生一個(gè)電場。，材料才具有最優(yōu)或最理想的綜合性質(zhì)。相反，材料工程是根據(jù)材料的結(jié)構(gòu)與性質(zhì)的關(guān)系來涉及或操控材料的結(jié)構(gòu)以求制造出一系列可預(yù)定的性質(zhì)。，所有固體材料的重要性質(zhì)可以分為六類：機(jī)械、電學(xué)、熱學(xué)、磁學(xué)、光學(xué)、腐蝕性。因此，有時(shí)候有必要為某一性質(zhì)而犧牲另一性能。操控和移動原子和分子以形成新結(jié)構(gòu)成為可能，因此，我們能通過一些簡單的原子水平的構(gòu)建就可以設(shè)計(jì)出新的材料。3． 金屬的強(qiáng)度表明原子是通過強(qiáng)的鍵結(jié)合在一起的。相似的，當(dāng)比重小于1時(shí)，物體將漂浮在水面上，當(dāng)比重大于1時(shí)，物體會沉降。反磁性材料的相對導(dǎo)磁率小于1，但是到目前還沒有哪種材料的相對導(dǎo)磁率遠(yuǎn)小于1。3．材料的承載方式極大地影響了材料的力學(xué)性能，也決定了材料失效形式，以及在失效前是否有預(yù)警。while ductility, fracture toughness, and elongation usually the respective of what is happening within a material, stress is the internal distribution of forces within a body that balance and react to the loads applied to strain is defined as the amount of deformation in the direction of the applied force divided by the initial length of the material with high strength and high ductility will hace more toughness than a material with low strength and high Unit 6 ，材料科學(xué)與工程界有責(zé)任和機(jī)遇通過解決未來世界的需求—在能量、交通、住房、飲食、回收和健康方面的需求來改變世界。 domestic productmaterials science and engineeringmarket economySocietal issueseconomic indexsanitationGross national productpopilation growth rate things that have been constant over time are human innovation and creativity, the engineer’s ability to address societal needs, and the entrepreneurial spirit of have witnessed the reshaping of our lives through revolutions that hace taken place in medicine, telemunications, and transportantion percent of the world’s population lacks access to safe drinking water and nearly 40% has no access to and society are interlinked, and it is only rational that we should see a close relation between the MSE research agenda and societal issues that affect the human condition on the 7 ，金屬是一類容易失電子以形成正離子的元素，它與其他金屬原子形成金屬鍵。4．Protective filmcircuitFree electronelectron transferMetal cationanode reaction metals, such as gold and silver, can be found in the earth in their natural, metallic state, and they have little tendency to is the process of stripping electrons from an atom and reduction occurs when an electron is added to an the surface bees wet, corrosion may take place through ionic exchange in the surface water layer between the anode and is monly classification based on the appearance of the corroded 10 （研究）這些性能，看它們與我們所期望的陶瓷的組成有多匹配。 glass transition temperatureioniccovalent bondStress distributioncoefficient of thermal expansionGlass optical fibrematerials science and engineeringSolidoxide fuel cellselectron microscopy , which is classified as a ceramic, has the highest thermal conductivity of any known are stronger in pression than in tension, whereas metals have parable tensile and pressive generally have low toughness, although bining them in posites can dramatically improve this functions of ceramic products are dependent on their chemical position and microstructure, which determines their 11 —合成與加工，結(jié)構(gòu)與組成，性質(zhì)與性能之間的相互聯(lián)系來定義的。 ceramicsgrain boundaryAlkaline earth oxideoxide additiveTriple pointsaturation magnetizationTelevision tubethe color scale understand the behavior and properties of any material, it is essential to understand its grain size is determined by the size of the initial powder particles and the way in which they were 4 or translucent ceramics require that we limit the scattering of light by pores and secondphase ceramics are used as electrical insulators because of theie high electrical resistivity and low dielectric 12 ，尤其在植入體和其它醫(yī)療器械方面是特別重要的。 reactionstress shielding Total hip prosthesestraintofailure ratio Mechanical stressflexural strength Martensitic transformation is a nonviable material used in a medical device intended to interact with biological repairs bee necessary when the existing part bees diseased, damaged, or just simply wears of its low density, cancellous bone has a lower E and higher straintofailure ratio than cortical stress shielding, by reducing E, is one of the primary motivations for the development of bioceramic are questions concerning the longterm effect of Unit 13 ，這個(gè)詞指的是一大類具有許多性質(zhì)和用途的天然材料和合成材料。這與完好晶體相具有非常明確的熔點(diǎn)不同。實(shí)現(xiàn)這些性能對控制和改進(jìn)機(jī)械性能和阻隔性能是非常重要的。但一般意義上的復(fù)合材料是指通過鍵的作用使兩種或多種不同的材料結(jié)合在一起的材料。，復(fù)合材料就既具有增強(qiáng)相的強(qiáng)度又具有基體的韌性從而得到了性能的理想組合，這是任何一種組分單獨(dú)存在時(shí)所具備的性能。thermosetThermoplasticYoung’s ModulusMechanical property constantsextreme enviroment contrast, isotropic material(for example, aluminuim or steel), in standard wrought forms, typically have the same stiffness regardless of the directional orientation of the applied forces and /or greatest advantage of posite materials is strength and stiffness bined with makes them ideal for use in products thar are exposed to extreme enviroments such as boats, chemicalhandling equipments and will never totally replace tranditional materials like steel, but in many cased they are just what we 18 。 propertybactericidal property Block copolymerinterfacial phenomena Exfoliated graphenemorphology control field of nanotechnology is one of the most popular areas for current research and development in basically all technical is considered where t