Part2Unit 12可编辑资料 - - - 欢迎下载Nanomaterial纳米材料Nanomaterial and Micro-machine纳米材料和微型机器可编辑资料 - - - 欢迎下载Nanomaterialsandnanotechnolologyhavebecomeamagicwordin modern society.纳米材料和纳米技术已成为现代社会一个具有魔幻颜色的词汇.generationofmaterialswithimprovedandtailorablepropertiesforapplicationscatalysis.insensors,optoelectronics,energystorage,separationandNanomaterialsrepresenttodaysfrontierinthedevelopmentofnovel advanced materialsand present great promises and opportunitiesfora new纳米材料代表了当今新型先进材料进展的前沿,为具有各种改良的，能依据人们各种要求进行“定制”的性能的新一代材料,在传感器，光电子学，储能，分别和催化剂技术等方面供应了宽敞的应用前景.So nanomaterials are considered as a great potential in the 21th century because of their special properties in many fields such as optics, electronics, magnetic, mechanics, and chemistry.因此纳米材料被视为21 世纪具有巨大的潜力的一种材料,由于在许多领域如光学，电子学，磁学，力学和化学他们的特殊性质.Theseuinquepropertiesareattractiveforvarioushighperformanceapplications. 这些特殊的性质对于各种不同高性能的应用程序来说具有很大的吸引力.Exampeplesincludewear-resistantsurfaces,lowtemperaturesinterable high-strength ceramics, and magnetic nanocomposites.例如耐磨的表层以及 在低温环境下具有高张力的陶瓷和磁力纳米复合材料.Nanostructured materials present great promises and opportunities for a new generation of materials of materials with improved and marvelous properties. 纳米结构的材料为新一代具有改良的特殊的性能的材料供应了宽敞的前景.It is appropriate to begin with a brief introduction to the history of the subject.在这里简洁介绍一下纳米材料的历史.Scientific work on this subject can be traced back over 100 years.在这可编辑资料 - - - 欢迎下载方面的科学争论可以追溯得到100 多年以前.In 1861 the British chemist Thomas Graham coined the term “ colloid ” to describe a solution contion containing 1 to 100 nm diameter particles in suspension.在 1961 年,英国化学家格雷姆首次用胶体 这个术语来描述一种含有直径为 1100nm 的微小悬浮颗粒的溶液.Around the turn of century, such famous scientists as Rayleigh, Maxwell, and Einstein studied colloids. 大约在 20 世纪末 20 世纪初的时候,一些出名的科学家如雷利 ,麦克斯韦和爱因斯坦开头争论胶体.In 1930 the Langmuir-Blodgett method for developingmonolayer films was developed.1930 年,单分子薄膜的狼缪尔布罗杰特方法形成.By1960Uyedahadusedelectronmicroscopyanddiffractiontostudy individual particles.到 1960 年 Uyeda已经用电子显微镜检查法以及衍射来争论单个粒子.Ataboutthesame time,arc,plasma,andchemicalflamefurnaceswere employed to produce submicron particles.几乎是同一时间 电弧,单离子体和化学反射炉已经用于生产亚微米粒子了.Magnetic alloy particles for use in magnetic tapes were produced in1970.1970 年磁力合金粒子已经运用于磁带中了.By1980, studies were made on clusters containing fewer than 100 atoms.到 1980 年,已有许多人开头对含有不到 100 个原子的原子团进行了争论.In1985,ateam led bySmalleyand Krotofoundspectroscopic evidence that C60 clusters were unusually stable.在 1985 年,一个由斯莫利和克罗托领导的科研小组通过光谱分析证明白C60 原子团具有不同平常的稳固性.In1991, Lijima reported studies of graphitic carbon tube filaments.1991 年, Lijima 也报道了有关石墨碳管状丝材的争论情形.Research onnanomaterialshas been stimulatedbytheirtechnological applications.关于纳米材料的争论是在他们的技术的应用引起的.The first technological uses of these materials were as catalysts and pigments.这些纳米材料的第一次技术使用是催化剂和自然色素运用.The large surface area to volume ratio increases the chemical activity.大面积的体积比增加到化学活动上.Because ofthisincreased activity,there aresignificantcostadvantages in fabricating catalysts from nanomaterials.可编辑资料 - - - 欢迎下载正由于这些增加的争论,从纳米材料上制造催化剂才有了巨大的成本优势.The properties of some single-phase materials can be improved by preparing them as nanostructurs.一些单相的材料的性能仍可以通过纳米结构来优化.For example, the sintering temperature can be decreased and the plasticity increased on single-phase, structural ceramics by reducing the grain size to several nanometers.例如,降低燃烧温度,把颗粒大小缩小几个纳米,可以单相的提升建筑陶瓷的可塑性.Multiphase nanostructured materials have displayed novel behavior resulting from the small size of the individual phases.由单个颗粒的小型体积,多相的纳米结构材料已经出现了非比平常的性质.In microelectronics, the need for faster switching times and ever larger integration has motivated considerable effort to reduce the size of electronic components.在微电子学中,对快速转换时间和更大规模的集成电路的需要在减小电子元件尺寸的工作起到了很大的作用Increasing the component density increased the difficulty of satisfying cooling requirementsandreducestheallowableamountofenergyreleasedon switching between states.而增加器件密度又会增加必需中意冷却条件以及削减开关状态转换是所答应的最大能量释放的难度.Itwouldbeidealiftheswitchingoccurredwiththemotionofasingle electron .在单电子的移动时开关是最理想的状态.One kind of single-electron device is based on the change in the Coulombic energy （库伦能） when an electron is added or removed from a particle . 当从一个粒子中增加或较少一个电子的时候,一种单电子装置是以库伦能的变化为基础的.For a nanoparticle this energy change can be large enough that adding a single electron will effectively block the flow of other electrons.对于纳米粒子来说,这个能量的变化因增加单个电子有效的限制其他电子的流淌而充分.In addition to technology, nanomaterials are also interesting systems for basic scientific investigations.除了技术,纳米材料的基本科学调查也是好玩的系统.可编辑资料 - - - 欢迎下载Forexample , smallparticl