真升机巡视1000KV交流特高压线路的安全作业距离

在特高压线路巡检技术中,直升机巡视,因其巡视角度和携带的高科技装备,具有人工巡检无法比拟的优点,尤其是在巡视塔头细节和发现红外、紫外特征缺陷方面有着巨大的优势。研究和讨论直升机在巡视1000kV交流特高压线路的安全距离方面的应用。通过对带电安全距离、电磁场强度及飞行控制等方面的研究．解决了直升机巡视交流特高压线路的关键技术问题．并以此为基础开发出整套的交流特高压线路巡视方法．最终在带电的特高压线路上成功进行了正式的直升机巡视作业。     

高压加热器端差变化对机组安全及经济性的影响

对高压加热器疏水温度高的原因进行了全面分析,由疏水温度变化对机组安全及经济性的影响进行了全面论述和计算,证实汽轮机的回热系统有一定的节能潜力。     

基于安全应用支撑平台的电子政务应用系统

论文首先简述了电子政务信息安全的要求,分析了电子政务应用系统在信息安全上存在的主要问题,重点阐述了如何将统一的安全应用支撑平台与电子政务应用系统有机结合,进而全面提升网络与信息安全水平的对策措施。     

大直径盾构负环管片拆除及隧道换装技术

通过对北京铁路地下直径线2标工程的研究,确定在刀盘改造期间进行负环管片拆除的一系列工作,重点如部分反力架的拆除方法、负环管片的详细拆除方法以及拆除反力架后临时支撑的架设方法,同时就泥水盾构隧道的换装技术进行了叙述,最终在7d之内成功拆除了7环负环管片,节约了工期,保证了后继施工的材料运输速度。     

A novel bird-nest-like air superoleophobic/superhydrophilic Cu(OH)2-based composite coating for efficient oil–water separation

An air superoleophobic/superhydrophilic composite coating with a unique structure was fabricated by oxidation and further modification of the copper mesh, and its design principle was clarified. This unique bird-nest-like configuration gives it instant superhydrophilicity due to the high surface roughness and high polar surface free energy components, while air superoleophobicity is caused by its extremely low dispersive surface free energy components. Furthermore, a water-resistance mechanism was proposed whereby a polyelectrolyte plays a critical role in improving the water-resistance of fluorosurfactants. It can separate oil–water mixtures with high efficiency (98.72%) and high flux (25185 L·m⁻²·h⁻¹), and can be reused. In addition, our composite coating had certain anti-acid, anti-alkali, anti-salt and anti-sand impact performance. More importantly, after being soaked in water for a long time or being exposed to the air for a long time, it still retained ultra-high air oil contact angle and showed excellent stability, which provided the possibility for practical applications. Thus, these findings offer the potential for significant practical applications in managing oily wastewater and marine oil spill incidents.     

Adsorption and Desorption of Zn,Cu, and Cr by Sediments from the Raisin River (Michigan)

Metal adsorption by Raisin River sediments in vitro depended linearly on soluble metal concentration to adsorption densities of 6,000–9,000 μg/g with 48 hr partition coefficients of approximately 50, 30, and 25 L/g for Cu, Cr, and Zn, respectively. Partition coefficients computed from field data spanned a comparatively wider range of values in a manner consistent with the often reported adsorbent concentration effect, but other factors likely contributed, too. Desorption of Zn was complete and rapid (24–48 hr) in contrast to Cr, which was incomplete and much slower; Cu desorption was intermediate to Zn and Cr. A reversible-resistant equilibrium model (DiToro et al. 1986) could not describe the observations as Cu and Cr had not reached metastable desorption equilibria after 24 days. Metal desorption, however, could be described kinetically by distributing sorbed cations between either of two classes: rapidly desorbing and slowly desorbing cations. Sequential and simultaneous desorption models gave similar predictions. Aqueous chemical considerations suggested precipitated as well as adsorbed species could give rise to the observations, but available data did not permit adequate tests of this hypothesis. The extent to which kinetic constraints rather than irreversible reactions account for the desorption-resistant binding signifies a potentially greater metal mobility or bioavailability than would otherwise be assumed.     

纳米ATO粉体的高度均匀与稳定分散研究

纳米氧化锡锑(ATO)粉体的高效分散和长期稳定是制备纳米透明隔热材料的关键因素。首先考查了分散剂、pH值、粉体表面特性、分散工艺、粘度等参数对分散稳定性的影响,采用沉降法、分光光度计法、电镜法对分散效果进行表征。结果表明,采用复合分散剂,其添加量占粉体质量5%,同时采用超声和球磨相结合的分散方式可以使分散效果达到最佳;通过增加粉体表面球度和分散介质粘度的方法可以有效提高粉体的分散稳定性,pH值对粉体分散稳定性影响不大。最后,通过优化分散工艺得到了高度均匀、长期稳定的纳米ATO分散液及纳米透明隔热涂料。     

Pitting morphology in single crystals of copper during and after cyclic deformation in 0.1 M perchloric acid

The morphologies of corrosion pits produced during cyclic deformation have been studied in copper single crystals exposed to corrosion, and by exposing previously cycled specimens to the same corrosive environment (0.1 M HClO₄), but without cycling. When the previously deformed metal was corroded without cycling, pits formed at moderate and high anodic potentials with 111 facets, and two morphologies were observed; regular octahedral pits with pointed bottoms and others with flat 100 bottoms. The existence of the flat-bottomed pits was justified thermodynamically, and the sharp bottomed pits developed from the other kind because of the mechanism and kinetics of the growth process. The corrosion pits produced during cyclic deformation were not of the conventional octahedral type and showed 110 and 111 facets. The slip steps caused by the cyclic deformation reduced the differences in specific surface energies of the facets, and stimulated the growth kinetics.     

容迟网络体系结构及其关键技术研究

当前的Intemet体系结构和其中许多协议无法很好的适用存在高延迟和频繁割裂的网络.当端节点具有严格的能量和存储限制时,这一问题将更加恶化.由于移动性和特殊应用需求,使得像陆地移动网络、军事无线自组织网络、星际网络及无线传感器网络等这样的受限网络缺乏“保持连接”的基础结构.这些受限网络有它们自己的专有协议而不采用TCP/IP协议.为了实现这些网络之间的互联,国际上提出了在端到端连接和节点资源都受限时的一种新型网络体系结构和应用接口,称为延迟容忍网络(简称容迟网络,DIN,Delay-Tolerant Networks).DTN作为网络互联时传输层上的覆盖网可用来满足随意的异步消息可靠转发.本文研究分析了容迟网络的应用背景、体系结构、关键技术和一些开放问题,并给出了未来的发展方向和应用前景.     

基于网格技术的电子政务平台研究与设计

电子政务已经成为世界各国政府行政管理改革的主要方向,建立电子政务将可以促进业务系统的互联互通和信息共享,提高政府的监管能力、服务质量。在电子政务建设过程中,由于历史原因遗留下来的信息孤岛,造成了协同工作困难和效率不高等问题。近年来,随着网格技术的迅猛发展,网格技术为消除信息孤岛、促进资源共享、实现工作协同等找到了新的解决途径。本项研究把网格技术引入了电子政务领域,使电子政务显示出了良好的发展前号。