水热法制备BaTiO3粉体

水热法制备的陶瓷粉体结晶度高，团聚少，烧结活性闹，得到了越来越广泛的重视。本文报道了水热法制备ＢａＴｉＯ３粉体的研究结果，给出ＢａＴｉＯ３粉体晶粒组成、粒度和结晶形貌与反应温度、前驱物形式以及Ｂａ、Ｔｉ摩尔比之间的关系，选择较高的反应温度，使用强碱性溶液以及较高ｍ（Ｂａ）．ｍ（Ｔｉ）比的前驱物，有利于钙钛矿型ＢａＴｉＯ３晶粒的形成。采用新制的Ｔｉ（ＯＨ）４胶体为前驱物，在Ｂａ（ＯＨ）２水溶液水热反     

食品级丙酸锌的合成工艺研究

以丙酸钙和硫酸锌为原料，经分解反应合成了一种新型食品添加剂－丙酸锌，此反应的优化条件是：n(丙酸锌）:n(硫酸锌）＝1.16:1，c(丙酸钙）＝1.075mol/L,c（硫酸锌）＝1.239mol/L，反应温度为80℃，反应时间为40min，丙酸锌产率可达93.6%，其各项技术指标经检测符合同类产品食品级标准要求。     

热水用塑料管材的选用方法

介绍了用于生活热水、各种供暖热水的塑料管的力学性能和使用条件以及基于ISO标准的选用计算方法，给出了其管径标注方法。     

测量空气中Rn,Tn子体的α谱法

本文介绍了测量空气中Rn、Tn子体浓度的α谱法,给出相对标准偏差的计算公式及计算机程序框图,讨论了此方法的固有不确定性及其影响因素,给出最佳实验条件。     

Structural behaviour of aeronautical tungsten carbide/carbon-coated titanium ball screws under space thermal-vacuum conditions

In view of the pressing need for improvements in space mechanisms and tribology research work, a thermal high‐vacuum mechanism test facility has been constructed at Rome ‘La Sapienza’ University. The purpose of this facility is to provide fundamental data on the performance of mechanical components and materials in high vacuum in order to test the validity of space mechanism designs. The facility also makes it possible to examine the behaviour of both mechanisms and materials under combined environmental factors, such as ultraviolet radiation, atomic oxygen and temperature. This paper reports on the behaviour of titanium recirculating ball screws provided by Umbra Cuscinetti SpA (Foligno, Italy) under thermal‐vacuum conditions. It is to be noted that these ball screws—well known in the aeronautical field—may be particularly attractive as a new generation of space mechanisms. A solid multilayer film of tungsten carbide/carbon (WC/C) was deposited on screw surfaces as a lubricant and was then compared with the case of no lubrication, which presently appears promising for many mechanisms. In order to compare experimental results, traditional stainless steel mechanisms were also tested and analysed. The requisites imposed by the space environment, as well as by contact mechanical stresses, have given useful information on a preliminary geometrical configuration and choice of materials, both of which are presented in this paper. Thermal‐vacuum effects on overall ball screw efficiency and on ball screw coating friction and wear are also reported and commented on herein as well as numerical contact simulations of crack mechanisms.     

Depression in Multiple Sclerosis: A Quantitative Review of the Evidence.

The published literature on depression in multiple sclerosis (MS) is reviewed quantitatively. The authors report mean effect sizes for 20 studies comparing depression scores of MS patients with those of healthy participants (d=1.07) and 21 studies comparing depression scores of MS patients with those of patients who have other chronic conditions (d=-0.14). The confidence interval for the mean overall MS-medical comparison included 0. However, subgroups of patients with chronic fatigue and spinal-neuromuscular conditions were more and less depressed than MS patients, respectively. Results indicate that a majority of MS patients with mild to moderate disability levels are distinguishable from healthy people in terms of depressive symptoms. However, the depression-disease link is complex and not specific to this form of demyelinating illness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

超短波水情自动测报系统常见故障分析与处理

结合紧水滩水情自动测报系统近10年的维护情况，对超短波水情自动测报系统常见故障按遥测站、中继站和中心站进行分类分析，并提出各种故障的分析与处理过程。     

Effects of molding conditions on the electromagnetic interference performance of conductive ABS parts

Polymers filled with conducting fibers to prevent electromagnetic interference (EMI) performance have recently received great attention due to the requirements of 3C (computer, communication, and consumer electronics) products. In the present article, the effect of fiber content and processing parameters, including melt temperature, mold temperature, and injection velocity, on the electromagnetic interference shielding effectiveness (SE) in injection molded ABS polymer composites filled with conductive stainless steel fiber (SSF) was investigated. The influence of fiber orientation and distribution resulting from fiber content and molding conditions on EMI performance was also examined. It was found from measured results that fiber content plays a significant role in influencing part EMI SE performance. SE value can reach the highest values of approximately 40 dB and 60 dB at 1000 MHz frequency for fiber content 7 wt % and 14 wt %, respectively, under the best choice of molding conditions. Higher melt and mold temperature would increase shielding effectiveness due to a more uniform and random fiber orientation. However, higher injection velocity leading to highly‐orientated and less uniform distribution of fiber reduces shielding effectiveness. Among all molding parameters, melt temperature affects SE performance most significantly. Its influence slightly decreases as fiber content increases. Injection speed plays a secondary importance in affecting SE values, and its influence increases as fiber content increases. Upon examination of fiber distribution via optical microscope and subsequent image analysis, it was found that the fiber becomes more densely and random distributed toward the last melt‐filled region, whereas fiber exhibits less concentration around the middle way of the flow path. This can be attributed to the combined effects of fountain flow, frozen layer thickness, and gapwise melt front velocity. The results indicate that molding conditions, instead of fiber content alone, are very important on the SE performance for injection molded SSF filled ABS composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1072–1080, 2005     

PVA/MMT/TiO2三元复合薄膜制备与研究

通过插层法和溶胶-凝胶法制备了PVA/MMT/TiO2三元复合薄膜。结果表明，MMT、TiO2均匀分散于基体中，由于无机柱子的协同增强作用．PVA／MMT／TiO2三元复合薄膜的热分解温度比纯PVA薄膜提高了59℃：MMT的质量一定时．复合薄膜的拉伸强度、直角撕裂强度和弹性模量随TiO2质量分数的增加而增加。并在TiO2质量分数为1.0％时分别达到最大值，但断裂伸长率则一直下降.MMT质量分数为3．0％、TiO2质量分数为1．0％、pH为7、搅拌3h和反应温度90℃条件下．制得的复合薄膜的性能最佳。     

岩溶陷落柱发育的地质环境及导水类型分析

根据刘桥一矿已揭露岩溶陷落柱的现场调查，结合以往华北煤田陷落柱资料，论文探讨了陷落柱发育的地质环境，认为可溶性岩层、地下水迳流、区域性贯穿陡倾节理、层滑构造和以重力为最大主动作用力是岩溶陷落柱发育的必要条件，并在此基础上分析岩溶陷落柱柱边围岩结构变化特点，总结了陷落柱识别方法以及导水类型。