【正文】 ograve life cycle of materials relative to the overall manufacturing process.(Selected from Materials Science and Engineering: An Introduction, by William DCallister,2002) New Words and Expressionsintermediate a. 中間的；n. 媒介，中間品 ceramic n. 陶瓷，陶瓷制品 polymer n. 聚合物，聚合體，聚合材料 posite n. 復(fù)合物，復(fù)合體，復(fù)合材料 semiconductor n. 半導(dǎo)體，半導(dǎo)體材料 biomaterial n. 生物材料 implant n. 移植，植入 oxide n. 氧化物 carbide n. 碳化物 brittle a. 脆的，易碎的 recycle n. (使）再循環(huán)，再利用，回收 transparent a. 透明的，顯然的，明晰的 lustrous a. 有光澤的，光輝的 impurity n. 雜質(zhì)，混雜物，不潔，不純 circuitry n. 電路 despoil ，掠奪 renewable a. 可更新的，可恢復(fù)的 Unit 3 Materials Research: Today and Future The future of the business in polymeric materials is influenced to a large extent by three factors: macrotrends in society, developments in science and technology and the oute of the present turmoil in the chemical industry. Looking at the future needs of the society, it is expected that an increasing pressure will be exerted in the next decades by the society at large on the chemical industry, to e to a higher level of sustainability. The development of really sustainable products and processes will bee more and ore important. On the other hand, the most striking development in material science and technology is an ever increasing control on the molecular and the supramolecular level, up to the nano length scale. The interest of polymer scientists has shifted from new monomers and their (co) polymers towards functional and smart materials, resulting from the mimicking of the perfect control of macromolecular structure and function as found in nature. It is expected that these developments will provide the solutions for more sustainable products and processes. The third factor is a thorough reshuffling of the activities in the chemical industry. The position of the 39。be exposed to,暴露，面臨，處于……境地。 mechanical, electrical, thermal, magnetic, optical, and deteriorative. For each there is s characteristic type of stimulus capable of provoking different responses. Mechanical properties relate deformation to an applied load or force: examples include elastic modulus and strength. For electrical properties, such as electrical conductivity and dielectric constant, the stimulus is an electric filed. The thermal behavior of solids can be represented in terms of heat capacity and thermal conductivity. Magnetic properties demonstrate the response of a material to the application of a magnetic field. For optical properties, the stimulus is electromagnetic or light radiation: index of refraction and reflectivity are representative optical properties. Finally, deteriorative characteristics indicate the chemical reactivity of materials. In addition to structure and properties, two other important ponents are involved in the science and engineering of materials, namely processing and performance. With regard to the relationships of these four ponents, the structure of a material will depend on how it is processed. Furthermore, a material39。s performance will be a function of its properties. Thus, the interrelationship between processing, structure, properties, and performance is linear as follows:Processing→Structure→Properties→PerformanceWhy Study Materials Science and Engineering? Why do we study materials? Many an applied scientists or engineers, whether mechanical, civil, chemical, or electrical, will be exposed to a design problem involving materials at one time or another. Examples might include a transmission gear, the superstructure for a building, an oil refinery ponent, or an integrated circuit chip. Of course, materials scientists and engineers are specialists who are totally involved in the investigation and design of materials. Many times, a materials problem is to select the right material from many thousands available ones. There are several criteria on which the final decision is normally based. First of all, the inservice conditions must be characterized. On only rare occasion does a material possess the maximum or ideal bination of properties. Thus, it may be necessary to trade off one characteristic for another. The classic example involves strength and ductility。參考譯文：許多應(yīng)用科學(xué)家或工程師，……，在某個時候都將面臨著涉及材料的設(shè)計問題。advanced materials39。 and 39。life sciences39。 Economic advantage due to the low costs of process.material sciences39。 and puts forward that nature reached a tremendous level of control and plexity with a limited number of chemical systems. In synthetic chemistry on the contrary, we can synthesize an unlimited number of monomers, building blocks and backbones but, until recently, with very limited control and plexity().Biology biotechnology Molecular nanotechnology Synthetic chemistry controlled plexity diversity Natural and synthetic chemistry In recent years progress has been made in two ways. The diversity in molecules synthesized by living organisms is increased by biotechnology. On the other hand a substantial jump has been made in synthetic chemistry towards more control and plexity, the socalled molecular nanotechnology or nanochemistry. J. M. Lehn drew an arrow in the diagram and said that progress would he made in that direction. This means that continuous mutual interaction between the two fieldsbiotechnology and molecular nanotechnologycould offer countless opportunities for new concepts.Time amp。, JeanMarie Lehn pares39。 furthermore, they have very large molecular structures. These materials typically have low densities and may be extremely flexible. Composites: A number of posite materials have been engineered that consist of more than one material type. Fiberglass is a familiar example, in which glass fibers are embedded within a polymeric material. A posite is designed to display a bination of the best characterist