Formation of ordered microporous films with water as templates from poly(D,L‐lactic‐co‐glycolic acid) solution

Recently a method that uses water droplets at the air–solution interface as an ordered template was reported for the preparation of ordered micrometer‐size honeycomb structures. Here we show that the method can also be used for formation of honeycomb‐like porous films from random copolymers with certain hydrophilicity, besides those polymers with defined structures such as block copolymers, starlike homopolymers, amd amphiphilic polymers. This demonstrates that the stabilization of water droplets is the key factor for the regular structure. Also we indicate that size and structure of the films can be regulated by such variables as concentration and atmospheric humidity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1846–1850, 2003     

Alleviation Effect of Lanthanum on Cadmium Stress in Seedling Hydroponic Culture of Kidney Bean and Corn

Since1970s,rare earths(RE)have been exten-sively used as micro-fertilizers for crops in China.Ithas already been proved that REcani mprove the pro-duction and quality of crops.However,there havebeen a fewinvestigations about using RE as regulatorin pollution ecology.For example,An et al[1]studiedthe effects of O3on wheat growth and the protectiveeffect of RE.Yan and Zhou et al[2,3]discussed theprotective effect of RE on plants under acid rainstress.Jia et al[4]and Hu et al[5]reported th…     

松辽南部早白垩世断陷期沉积相与成岩相

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光通信用垂直腔面发射激光器的进展

垂直腔面发射激光器(VCSEL)以其优异的性能有望成为信息时代的新光源.文章介绍了用于光通信的VCSEL的开发现状.     

重视标准工作、强化标准管理是企业生存与发展的基础

本文论述了企业标准化工作的重要性及标准化工作需重视的几个方面。论述了采用国际先进标准及建全标准化管理体系的重要性。     

关于我国资源保障能力的若干思考

资源保障能力是一国综合国力判断的重要指标之一。本文首先界定了资源保障能力的涵义，然后分析了五个对资源保障能力比较重要的影响因素，即资源禀赋、经济发展水平、科学技术因素、政治因素和人们的资源观，最后得出几点我国提高资源保障能力的建议以供参考。     

基于网络的家电产品故障诊断系统研究

介绍了基于网络的家电产品故障诊断系统的硬件拓扑结构、软件平台及系统开发。系统在硬件上采用了多种网络平台搭建方式及综合连接技术，软件上采用了IDRS诊断模型和基于事例的最新诊断技术。这也是诊断研究和应用的新领域。     

浅析上海市建筑防水材料近况

本文浅析了上海市建筑防水材料的生产、质量及应用情况,并对防水工程的发展提出了建议。     

DLL23XA双侧向测井仪的研制

以往双侧向测井仪动态范围小，测量精度低，为此开发了DLL23XA双侧向测井仪。该仪器主要单元采用厚膜电路，稳定性、一致性好；深、浅屏流源采用可变功率控制，提高了仪器的动态范围。仪器采用3506P例进行数据传输，可方便地配接各种地面系统。     

静电火灾的产生及其防治

文章详细分析了静电产生的机理，指出积聚静电电荷的多少与材料的电阻率和介电常数有关。讨论了静电火灾发生的条件，指出静电火灾的发生具有隐蔽性、复杂性和突发性。但只要对其规律进行深入地研究，可以找到有效地防止静电火灾发生的办法。