Determination of the modified effect of nano-SiO2 by titration in nonaqueous phase

The dispersion of nanosilica that was modified and original in organic solvents could be judged directly by using methyl red as the indicator, and the principle of color development was also discussed. A method has been developed for the determination of the acidity of solid surfaces, which consists of titration of the solid suspended in benzene with n-butyl amine, using neutral red as the indicator. Basic indicator forms a red color on acidic solids, and the end-point of the titration is the disappearance of the red color. The text was submitted by the authors in English.     

Surface modification of nano-SiO2 by in situ grafted polymerization of butyl methacrylate

Silane coupling agent was used to introduce polymeric groups that was C=C onto the surface of nano-SiO₂ particles by self-assembling technique. Then, in situ grafted polymerization was carried out between the functionalized particles and butyl methacrylate monomers under the action of an initiating agent to accomplish the surface modification of nano-SiO₂. The effect of different reaction conditions on grafting percentage was studied, and analyses of FTIR, TEM, and TG-DTA results show that new organic chains were introduced onto the surface of nano-SiO₂, and the dispersion stability of nano-SiO₂ in THF was obviously improved. The text was submitted by the authors in English.     

Sintering and Electronic Conducting Properties of Lao.7Ca0.3CrO3 Perovskite Synthesized by a Glycine-nitrate Process

La0.7 Ca0.3 CrO3 powder consisting of superfine and uniform particles （ 100-200 nm ） were synthesized using a glycine-nitrate process （ GNP ）. The sintering and electronic conducting properties of La0.7 Ca0.3 CrO3 were invetigated in the sintering temperature range of 1 200-1 450 ℃. The desired morphology of the powder significantly improved its sinterability. La0.7 Ca0.3 CrO3 ceramics sintered at 1 250-1 450 ℃ show high relative densities above 95 % . The ceramics sintered at 1 250-1 400 ℃ have very similar electronic conduct- ing properties, providing electronic conductivities around 55 Ω^-1 cm^-1 at a measuring temperature of 800 ℃ . Further increasing the sintering temperature to 1450 ℃ led to an apparent degradation of electronic conducting properties. This research demonstrates the advantage of the GNP in producing La0.7 Ca0.3 CrO3 with respect to the enhanced sintering properties and superior electronic conducting properties.     

基于Quick Server的IPv6 Ftp服务器设计与实现

基于QuickServer设计并实现了支持IPv4和IPv6协议的Ftp服务器。对IPv4环境中的应用程序向IPv6迁移进行了实质性的探索和研究。     

CSP热连轧机振动性质的确定

针对某钢厂CSP热连轧机出现的振动问题,综合运用现场实测和计算机仿真的方法对轧机振动的性质进行了系统的分析,并得到了如下初步结论:工作辊水平方向的振动是由主传动系统的扭转振动引起的强迫振动。     

深脱硫钢在LF炉中的脱硫处理

讨论了LF炉添加脱硫剂对深脱硫钢进行脱硫的机理、脱硫剂的渣系选择及组成,并结合生产情况,着重介绍了LF炉添加脱硫剂的应用技术和效果.     

全数字组态测温系统设计

本文提出了由数字温度传感器组成的组态测温系统。它可使用手持设备调试器进行现场调试，并采用OPC和组态技术进行集成。文中详细阐述了系统组成原理，组件对象模型接口技术及组态软件。在本文基础上设计的测温单元已能在实际中应用。     

履带车辆电传动系统电气机械联合制动优化控制与仿真

根据电传动研究情况,提出了电传动电气机械联合制动优化控制目标;在这个目标下,完成了电气制动控制策略优化,进行了原车机械制动系统在联合制动中制动力的分配,通过试验和仿真说明它的合理性;最后给出联合制动的仿真结果,并进行了分析。     

Influence of interfacial strength on the fracture toughness of glass-ceramic matrix composites

Nine kinds of glass-ceramic matrix composites with different compositions and interfacial strength (τ _s) were prepared. The influence of τ _s on the fracture toughness(K _1c) of composites was studied. It was discoved that, for the system no chemical reaction taking place at the interface, K _1c increased proportionally with τ _s increasing at the first stage, then decreased when τ _s reached a certain value. According to this result, a model of relationship between τ _s, thermal mismatch (Δα _r) and K _1c was built up. If a chemical reaction took place and a new phase was formed in the interface, the K _1c of composite was effected by the combination of τ _s, chemical bonding, radial interfacial stress and other factors. Project supported by the National Natural Science Foundation of China Synopsis of the first author Wang Lingsen, professor, born in 1938, current research field: special ceramic and ceramic matrix composite, etc.     

超级有限元法及高耸桁架结构的超级元列式

介绍了一种大型结构分析的新的数值方法超级有限元法。利用该方法可大大降低结构分析的计算工作量。本文推导了高耸桁架结构的超级元列式，可用于塔架等大型桁架结构的力学分析。算例说明这是一种实用的大型复杂结构分析的数值方法。