浅谈新型给排水管材的选用

为保证城市供水管网的水质,改善配水压力,减少镀锌钢管锈蚀对居民健康和生活质量的影响,国家建设部建材局等部委联合发文（建科1997第154号）〈国家化学建材推广应用“九五”计划和2010年发展规划纲要〉,根据文件精神和市自2001年1月1日起新、扩、改建的各类建筑物、构筑物、住宅小区的给水管道停止使用镀锌钢管,采用塑料给水管,这无疑极大刺激了塑料管行业的生产积极性,各种塑料管材也应运而生.     

我国物理类核心期刊网站建设研究

通过对我国物理类核心期刊网站建设现状进行分析和比较研究,指出我国物理类期刊网站建设存在的问题,并提出了改进建议。     

A distributed routing algorithm based-on simplified topology in LEO satellite networks

In this paper, a distributed routing strategy based on simplified topology (DRBST) was proposed for LEO satellite networks. The topology of LEO satellite networks was simplified aiming at minimizing inter-satellite links handover number. To optimize the route based on the simplified topology, we considered not only the transmission delay but also the queuing delay and the processing delay, which were analyzed using Markov chain and determined using a novel methodology. The DRBST algorithm was simulated in a LEO satellite networks model built using OPNET. The simulation results demonstrate that the low complexity DRBST algorithm can guarantee end-to-end delay bound. Moreover, the routing protocol cost is much less than traditional algorithms.