二氢叶酸还原酶在盐溶液中的分子动力学模拟

为了研究嗜盐酶如何在高盐环境下维持稳定性与活性,本文以沃尔卡尼极嗜盐菌及大肠杆菌的二氢叶酸还原酶(DHFR)为模型,将二者分别置于5种不同盐浓度的水溶液中进行分子动力学模拟。经9ns动力学模拟,得到了二者在不同浓度盐溶液中的运动轨迹,通过对运动轨迹的分析,获取了二者在不同盐浓度下的动力学特性。结果发现嗜盐古生菌的二氢叶酸还原酶自身所形成盐桥及与溶剂所形成的氢键均比大肠杆菌的二氢叶酸还原酶多,而溶剂可及性表面则要小,二者差异均达极显著水平。同时还分析了这两种分子及其氨基酸残基的柔性等。     

无机微粒表面接枝聚合改性进展

讨论了表面接枝改性机理,综述了"接枝到"(Grafting to)法和"由表面接枝"(Grafting from)法以及其它表面接枝改性方法的研究进展。     

增效超分散剂对铜酞菁颜料表面改性的研究

本文合成了几种增效超分散剂，并用于β-型铜酞菁的表面改性，其分散性、流动性和色光均有提高。结果表明，以聚酯为溶剂化链，胺或多胺类为锚基，通过砜基连接到铜酞菁分子上制成增效超分散剂。当超分散剂的用量由0％增加至8％时，体系的流动度由29增加到45；溶剂化链的分子量在1800-8000时，体系的分散性提高明显：在不同的脂肪胺中，多乙烯多胺效果最佳。这类分散剂都具有很好的抗絮凝性能，所制成的油墨长时间置放不分层。     

Plasma-sprayed coatings as adherend surface pretreatments

As part of the National Center for Manufacturing Sciences contract on adhesive bonding of dissimilar materials, UTRC, as a sub-contractor, is evaluating environmentally acceptable surface preparation techniques for selected metals and composites. The selected processes are automatable and capable of being transferred into the manufacturing arena. One aspect of the programme is the evaluation of plasma-sprayed, microporous, thin coatings as surface pretreatments for both resin-based composites and metals. Mechanical test results are presented which demonstrate the viability of this approach to achieve acceptable joint strengths with steel, titanium and aluminium bonded to several types of resin-matrix composite. The environmental impact, by elimination of organic primer systems and strong acid etching and anodizing solutions, will be discussed.     

二氧化硅改性二氧化钛光催化活性研究进展

二氧化钛是有代表性的一种n型半导体氧化物，其具有稳定性好、光催化效率高和不产生二次污染等特点，在很多方面有着广阔的应用前景。二氧化硅改性后的二氧化钛具有粒径小、比表面积大、吸附能力强、提高光催化效果等特点。介绍了二氧化硅改性二氧化钛的机理、制备方法以及其光催化效果。根据二氧化钛和二氧化硅的结合方式，分别从复合半导体、二氧化硅作负载、二氧化钛表面包覆二氧化硅等几方面进行总结。     

纳米材料的进展及其在塑料中的应用

介绍了近年来的纳米技术发展的概况，其中包括纳米粒子表面特性和表面改性的方法以及有机相界面改性的工艺路线。通过普通粉末、亚微米、微米级粉末和纳米级粉末作为兼填充剂填充效果的对比，突出了纳米级粉末优良的填充特性以及赋予复合材料的性能上质的飞跃的能力。     

NOTE The Application of Surface Analysis Techniques in the Adhesive Bonding of Oily Automotive Steel

There are fewer papers on the adhesive bonding of steel for structural applications than for aluminum and titanium alloys. However, the approach to the adhesive bonding of all three adherends has been similar, that is, the surfaces are pretreated prior to bonding. Trawinski, et al.^1,2,3 reviewed several conversion coatings or etching processes used for steel. Haak and Smith⁴ selected two surface treatments among nineteen based on minimal cost, simplicity and good durability. Smith⁵ has reported work on stainless steel-epoxy bonds under hydrothermal stress. Bischof, et al.⁶ investigated the effect of surface pretreatment of steel on bonding strength obtained with polyvinyl chloride. Ziane, et al.⁷ identified four fracture zones resulting from shear loading of epoxy bonded galvanized steel following four different surface pretreatments. But in some cases, as in the automotive industry, there is a need to bond oily steel directly without surface pretreatment. Rosty, et al.⁸ have reported a study of the role of fillers and cure temperature on the shear strength of oily steel bonded with epoxy. None of the reported research utilizes both microscopic and spectroscopic techniques to analyze the fracture surfaces.     

苯乙烯在纳米氧化锌表面的接枝聚合

用偶联剂γ-（甲基丙烯酰氧）丙基三甲氧基硅烷表面改性后的表面负载有乙烯基官能团活化的纳米氧化锌与苯乙烯在BPO热引发体系下进行接枝共聚，采用红外光谱、热失重和电子扫描显微镜对产物进行表征，实验表明苯乙烯成功地接枝到了活化后的纳米氧化锌表面上，当纳米氧化锌的用量为苯乙烯1％～8％（质量分数）时，纳米氧化锌的用量为苯乙烯4％（质量分数）左右时接枝率最高．     

沥青路面贫混凝土基层应力计算

为分析贫混凝土基层沥青路面新型路面结构的基层应力情况,通过有限元分析方法计算贫混凝土基层的荷载应力,并利用弹性层状体系理论分析沥青面层厚度对其影响,由此推导出基层荷载应力的计算公式.根据不同自然区划的温度场和最大温度梯度,得出贫混凝土基层沥青路面中的基层温度应力的有限元解,于此提出了基层温度应力的计算公式.上述两公式为贫混凝土基层沥青路面结构中基层厚度设计的重要依据.     

牡丹江地表水水质特征及评价

根据实测资料,分析了牡丹江水文站断面以上流域的地表水水质特征,并进行了较系统地评价.