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关键词： 材料化学   高性能   材料设计   分子设计  

摘要： 材料科学与工程,是一门多学科交义的新兴学科。本文将以高性能氮化物陶瓷的组成与显微结构设计为主题,探讨材料化学的作用。高性能氮化物陶瓷是一大族材料。它们的性能、特别是高温性能引人注目。而化学热力学与动力学研究,为设计与调控这类多相材料的相组成与显微结构,以适应苛刻条件下应用的

关键词： 中国化学会   配位化学   无机合成化学   学术论文   材料化学   勉曾   洪广言   金属氢化物   发光材料   发展规划  

摘要： 中国化学会第四届无机化学讨论会于1992年9月10～14日在北戴河召开,来自全国各地的400余名化学家,包括近10名学部委员参加了这次盛会。这次会议不仅是对近年来在无机化学领域成果的检阅、也是为纪念中国化学会成立60周年和维也纳创立配位化学100周年。

摘要： Writing of A Materials Chemistry Companion to General Chemistry, a reference for teachers that correlates standard chemistry topics with particular kinds of materials and their applications; includes exercises, demonstrations, and experiments.

摘要： This paper describes work on synthesis of chiral macromolecules as part of a materials chemistry study which seeks to establish links in these systems among molecular structure, three-dimensional molecular organization, and properties. The basic materials chemistry hypothesis driving this work is that chiral forces among stereogenic centers may serve as guiding fields to organize polymers in two or three dimensions. It follows that physical properties could be directly or indirectly controlled by chirality. In order to promote strong forces among chiral centers the chains were designed to have stereogenic carbons substituted by the strongly dipolar cyano group and spaced by 16 atoms along the backbone. The preparative chemistry of chiral macromolecules is challenging given the limited number of polymerization methodologies and the inherent translational periodicity of synthetic polymers. We have synthesized here low symmetry chiral macromolecules in which the only symmetry element retained is polar translation;achiral homologues lacking the nitrile function, the configurationally disordered polymer, and dimeric model compounds were prepared as well. The compounds exhibited crystalline and liquid crystalline phases, and significant differences were observed among homologues through differential scanning calorimetry and optical microscopy. The substitution of nitrile groups every 16 atoms along the polymer backbone, specially with configurational disorder, leads to glassy or less ordered condensed phases. In some Polymers when the strongly dipolar stereogenic centers do not have preferred handedness, chains organize into mesophases rather than crystalline structures. This is surprising since the concentration of stereogenic centers is extremely dilute. Using dimeric model compounds, homochiral recognition among stereogenic centers with large dipole moments was identified as an important factor in the assembly of molecules into layered structures. Interestingly, catena

关键词： 机电部   标准样品   技术标准   上海   化学成份   标样  

摘要： 在金属材料的研究和生产过程中,为了对材料质量的控制要进行大量的分析测试工作。标准物质(又称标准样品)的应用在保证分析质量,验证分析方法,校验仪器等方面是必不可少的。各工业发达国家都有较长的研制和应用标准物质的历史。我国在解放后的1951年为适应冶金工业的发展需要,受当时重工业部的委托由重工

关键词： CONDENSATION POLYMER   POLYSACCHARIDE   CELLULOSE   PULLULAN   GLUCOMANNAN   CHITOSAN   POLYAMINO ACID   LIQUID CHROMATOGRAPHY   GEL PERMEATION CHROMATOGRAPHY  

摘要： Gel production methods have recently been improved, and a systematic search for packing materials has led to the creation of various hard particles from hydrophilic condensation polymers, making it possible for aqueous gel permeation chromatographic separation to occur at higher flow rates. In the present review, we explain the production methods, efficiency, and applications of hydrophilic packings developed due to this improvement in packing materials, while especially emphasizing their hardness.

关键词： 材料化学   科技委  

摘要： 国家教委科学技术委员会组织的′91材料化学讨论会于91年11月12～15日在复旦大学东苑宾馆召开。会议的组委会成员有唐有祺、沈家聪、金声、林尚安、于同隐和杨玉良六位教授。参加会议的有国家教委,国家自然科学基金委,北京大学、清华大学、吉林大学、中

摘要： A review of the basic concepts and relevant scientific and technical issues in the new field of nonlinear optics and photonics is presented. The role the chemistry of organic materials may play in the development of new molecules with improved nonlinear optical properties is addressed. Numerous examples of chemical approaches are presented from our research as well as from other published work. We present our view on the question posed in the title. It is our intent to encourage the chemical community to become involved in the synthesis of novel organic / organometallic materials and bring to the attention of other disciplines the role materials chemistry may play in the development of the exciting area of nonlinear optics and photonics. © 1990, American Chemical Society. All rights reserved.

关键词： 美国   劳伦斯·伯克利实验室   高能物理   材料科学   X射线光学   新材料中心   国家电子显教镜学中心   冶金学   陶瓷学   材料化学   加速器设计   重离子物理   核医学  

摘要： LBL在高能物理、核物理、加速器、核仪器、能源、生物学、新材料、核技术应用、天文学等许多领域的研究都处于世界先进水平。现将其制定的十五年(1986—2003年)规划中的“科学技术规划”部分简要介绍如下,以起到抛砖引玉的作用。