High-Temperature Strength of Niobium Alloy 5VMTs with a Silicide-Ceramic Coating. Part 1. Short-Term Strength Characteristics

Experimental data on the short-term strength and plasticity of niobium alloy 5VMTs of the system Nb–W–Mo–Zr in its initial state, after annealing, and with a silicide-ceramic protective coating obtained by testing in vacuum, an inert atmosphere, and in air in the temperature range from 290 to 2270 K are analyzed. The process of microcrack initiation and propagation in the protective coating and matrix is investigated in high-temperature static tension. The limiting plastic strain values have been established at which the composite retains its load-carrying capacity in high- temperature aggressive and oxidizing gas atmospheres.     

Effects of lubrication and humidity on the abrasiveness of a thin boron carbide coating

Studies using thin boron carbide (B₄C) coatings have previously been performed in order to investigate their potential use as finite-life run-in coatings. Such coatings have been shown to polish the mating surface in a relatively short time. The inherent ability of these coatings to polish can potentially allow them to function as finite-life run-in coatings. Employing such coatings requires a thorough understanding of the parameters which directly influence the changes that occur in the coating abrasiveness throughout the duration of the polishing process. In past studies, changes in the coating abrasiveness during dry sliding wear under ambient conditions have been investigated. However, both lubrication and humidity can strongly influence the abrasive wear process. In this study, the influences of the operating environment, namely humidity and lubrication, on the coating abrasiveness are directly investigated. The coating abrasiveness decreases at a slower rate when a lubricant is added and when the humidity decreases.     

南京市冬季市区和郊区晴天大气边界层结构对比分析

应用2008年12月24—31日南京市区和郊区同步大气边界层观测资料,对晴天大气边界层结构进行对比分析．结果表明：南京地区冬季晴天,市区近地面层气温高于江北郊区近地面层的气温,市区热岛效应明显,且热岛强度夜间大于白天;市区逆温出现的时间滞后于郊区,逆温层高度也大于郊区．夜间,市、郊区风速随高度不断增大,并在一定的高度出现一个8m／s的极值中心．市区空气相对干燥．通过典型日分析,市区14：00干岛效应显著,相同高度上相对湿度一直低于郊区．在市、郊区近地面层中,愈近地面风速愈小;近地面层中白天风速最大,夜间最小;白天,大气层结不稳定,湍流混合作用强,上下层风速的差别趋于减小．市区风速在低层受建筑物影响．相同高度上小于郊区风速．     

消失模铸造铸铁件水基涂料的研制

选用石英粉为耐火骨料，酸式磷酸盐为粘结剂，通过正交试验确定了铸铁件消失模水基涂料的最佳配比。经测试和生产验证，其性能良好，能很好地适应生产要求。     

孔内深层超强夯法处理厚层人工回填土的应用研究

介绍了孔内深层超强夯法（SDDC）的基本原理,并将SDDC工法运用于处理某机场内厚层人工回填土地基,对无机固体废料进行了资源化回收利用。通过复合地基载荷试验、标准贯入试验和重型动力触探试验对SDDC施工质量进行检测,对SDDC桩体和桩间土的承载力效果进行评价。结果表明,经SDDC工法处理后的复合地基均匀性较好,承载力显著提高,达到工程使用要求。     

正极材料LiNi1/3CO1/3Mn1/3O2包覆LiNi0.8Co0.15Al0.05O2的性能

以NiSO4·6H2O、CoSO4·7H2O、MnSO4·H2O、NH3·H2O及NaOH为原料,采用共沉淀方法在LiNi0.8 C00.15 Al0.05 (OH)2球形粒子表面包覆一层Ni1/3 Co1/3Mn1/3(OH)2三元材料前驱体,配锂后在750℃下、氧气气氛中焙烧12 h,合成复合层状材料Li[(Ni0.8 Co0.15Al0.05)0.97(Ni1/3Co1/3Mn1/3)0.03]O2.复合层状材料具有核壳结构,包覆壳层的厚度约为1μm.复合层状材料在2.8～4.3 V充放电,0.1C首次放电比容量为188.2 mAh/g;0.2 C循环100次的容量保持率为96.2％;在55℃下以0.2C循环100次,放电比容量保持在163.2 mAh/g.     

D2、M2、S5模具扁钢脱碳特性实验研究

开展了在空气和氮气两种气氛下,采用Gleeble-1500热模拟机与普通电炉两种热方式、不同加热温度、加热时间对D2、M2、S5钢脱碳层深度影响的试验研究。依据试验结果,结合现场实际制定了较为合理的生产工艺并在现场成功应用,使上述模具扁钢脱碳层指标达到了美国ASTM－A681技术标准。     

二层交换机的攻击分析与防范技术的研究

本文通过OSI模型的第二层的特点,分析了二层交换机存在的安全隐患,提出了相应的解决办法。     

Effects of a base coating used for electropolymerization of poly(3,4-ethylenedioxythiophene) on indium tin oxide electrode

Electropolymerization of poly(3,4-ethylenedioxythiophene) (PEDOT) films on indium tin oxide (ITO), using a very thin PEDOT:poly(styrene sulfonate) (PEDOT:PSS) film as a base coating, was carried out in a non-aqueous solution containing the monomer, an electrolyte and propylene carbonate by a two-electrode system. For comparison, PEDOT film electrodeposited on bare ITO substrate under the same condition was also presented. The PEDOT films deposited on these two substrates were characterized by scanning electron microscopy, energy disperse X-ray spectroscopy and Raman spectroscopy. The results indicate that the PEDOT film electrodeposited on bare ITO was not uniform, while the PEDOT film electrodeposited on PEDOT:PSS/ITO has better uniformity. The compositions of the different regions of PEDOT film electrodeposited on bare ITO and PEDOT:PSS/ITO were studied and discussed. Electrochromic devices (ECDs) based on PEDOT films electrodeposited on bare ITO and PEDOT:PSS/ITO were fabricated and characterized by UV-Vis-NIR spectrophotometric study. The results show that the display contrast of the ECD based on PEDOT film electrodeposited on PEDOT:PSS/ITO was improved over that on a bare ITO substrate.     

Hydrogen plasma treatment of very thin p-type nanocrystalline Si films grown by RF-PECVD in the presence of B(CH3)3

Abstract

We have characterized the structure and electrical properties of p-type nanocrystalline silicon films prepared by radio-frequency plasma-enhanced chemical vapor deposition and explored optimization methods of such layers for potential applications in thin-film solar cells. Particular attention was paid to the characterization of very thin (～20 nm) films. The cross-sectional morphology of the layers was studied by fitting the ellipsometry spectra using a multilayer model. The results suggest that the crystallization process in a high-pressure growth regime is mostly realized through a subsurface mechanism in the absence of the incubation layer at the substrate-film interface. Hydrogen plasma treatment of a 22-nm-thick film improved its electrical properties (conductivity increased more than ten times) owing to hydrogen insertion and Si structure rearrangements throughout the entire thickness of the film.