Surface subsidence in the karst mining area in China

Carbonate rocks are widely distributed in China, with extensively scattering of karst aquifer deposits associated with frequent surface subsidences. Particularly, most of surface subsidences occurred in karst aquifer mining areas in Southern China, but very few in Northern China. As a form of geological hazard, the surface subsidence in mining areas causes the increasing of both the amount of mine water inundation and the possibility of mine water and mud invasion, jeoperdising the environment of mining areas, and endangering the mining operation and people’s lives. Generally, the distribution of surface subsidences is of regular pattern, principally controlled by karst development pattern. Therefore, it is likely to predict and prevent the occurrence of surface subsidence. In this paper, the distribution, the danger and the prediction and prevention of surface subsidence of karst aquifer mine area in China are discussed.     

Experience and perspectives of application of gasdynamic coatings in space technology

The given work deals with the results of the research carried out by the “Salute“ DB of the Khrunichev State research-and-production space center concerning the development of special equipment and improvement of the technique of the “cold“ gasdynamic method of application of coating for the accomplishment of several specific tasks: (1) development of the technique of application of a fireproof heat-radiating coating to screens made from stainless steel with coefficient of thermal radiation ε≥0.7; (2) development of technique of sealing (“curing“) of microleaks on the weld joints of the propellant tanks made of aluminum alloys; (3) study of the opportunity of sealing of joints of parts made from heterogeneous materials; (4) development of process for copper and nickel coating application for aluminium heat exchangers soldering.……     

基于绿色的煤机零件加工工艺方案的选择

由于煤矿机械所处的环境比较恶劣,因此其设计与制造一般只考虑本身的性能和使用寿命。结合煤矿机械产品的特点,从绿色角度探讨了煤机零件加工工艺过程模型,建立了绿色工艺评价体系,并对带式输送机中滚筒的加工工艺进行了分析,指出了今后煤机产品绿色制造的发展趋势。     

Improving fairness of TCP Vegas

TCP Vegas exhibits fairness problems even for flows with the same round‐trip time (RTT). We propose an enhanced Vegas with three revisions, replacing BaseRTT with RTT, detecting how fast acknowledgements return and the acceleration of the return speed. The impacts of each of the three proposed revisions are not ignorable. The proposed novel Vegas with the three revisions, called EVA, achieves better fairness under various network conditions. Copyright © 2004 John Wiley & Sons, Ltd.     

在形式之外--试论数字化时代建筑内涵的变化

数字化时代为建筑与空间的形式创作带来了前所未有的新的技术手段，但在形式之外，更为重要的是建筑内涵的变化。从作为媒介的建筑、城市与建筑的结构性重组，以及建筑的审美与象征意义三个方面，阐释了建筑在社会生活和时代变迁的影响下所发生的实质性转变。     

从仓储库房火灾中获得的经验和教训

历史的经验表明,当灾害性火灾发生后,人们对火灾进行调查所获得的经验和教训推动了仓储库房防火的进步。下面讨论由这种方式得出的经验和教训。1自动喷水灭火系统的设计应和火灾危险相匹配该教训来源于含有可燃物质的气溶胶罐仓库的自动喷水灭火系统的防火评估。1978年在新泽西     

塑料管道行业洗牌在即

近年来,国家化学建材领导小组相继出台了“关于加强我国化学建材生产和推广应用的若干意见”、“国家化学建材产业十五计划和2010年发展规划纲要”和“关于加速化学建材推广应用和限制淘汰落后产品的规定”等政策,这些政策大大加强了塑料建材的推广应用力度。在塑料管道行业发展前景一片光明而欣喜的同时,我们也不得不注意到这样一个情况,无论从市场需求还是资金的市场运作来看,塑料管道企业区域化、集团化形式已凸显出来。由于现阶段我国塑料管道产业集中度偏低,导致很多企业工艺装备小型化、科技水平低,造成产品缺乏竞争力,产品结构不合理…