Laboratory evaluation of a new device for water drainage in roadside slope along railway systems

The majority of the existing railway systems in China, from roadside slopes to retaining walls, suffered from poor drainage induced failures. Recently, a new drainage device was proposed to tackle these problems. Preliminary field implementations indicated that the new drainage device could effectively remove groundwater from the surrounding soil without any clogging effect. However, at present, most existing designs are purely based upon the engineers' personal experience and judgement; there is no well-established design method to take full advantage of the device.In this study, a series of laboratory modeling tests were conducted to investigate flow rates, and the optimum installation angle of the drainage device. After that, the long-term performance of the drainage device and conventional perforated PVC pipe under multiple wetting-drying cycles was also evaluated and compared. The results indicate that during the constant head tests, the flow rates in the new drainage device initially increased with an increase in the installation angles of the drainage device from 0° to 15°, and then decreased from 15° to 60°. An inclination angle from 5° to 15° is recommended for this new drainage device when installed in the exiting railway cut slope. The clogging effect was not a primary concern for the applications of this new device. The proposed drainage device provides an alternative way to tackle the poor drainage problem in the exiting railway cut slopes and retaining walls.     

PVC塑料抗静电地砖的施工应用

PVC塑料抗静电地砖主要由PVC、填充剂、增塑剂、颜料、稳定剂等组成，利用粒子界面间形成的导静电网络，连接地面金属网络，接地后形成整体防静电环境，具有永久性防静电功能。防静电效果达到防静电国标A级标准，且表面酷似天然石材花纹，装饰效果较好，还具有质量轻、耐磨、耐酸、耐碱、抗老化、阻燃等特点。     

我国钢铁工业中的清洁生产技术

对我国钢铁工业中的清洁生产技术进行了比较全面的概述，总结出其在废气治理、废水治理、固体废弃物治理、节能措施以及提高金属收得率等方面的实践措施。同时总结出发展清洁生产应该从源头和末端两个方面进行综合考虑，特别要重视在生产过程中的节能降耗、取得环境效益。     

Potential parameterization from proxy systems

We give an analysis and critique of a procedure for sequential multi-scale parameterization of so-called ab initio potentials. Such potentials are based upon a small selection of reference data generated at relatively low levels refinement of quantum mechanical (QM) methodology. Two closely related potentials for silica, BKS and TTAM, are explored in some depth because both have found frequent use in the literature of molecular dynamics simulation. The use of a single small molecular cluster as a proxy for the behavior of larger silica structures is shown to be perilous. Choices of ionic charge, basis set size, inclusion of electron correlation at some prescribed level of approximation, and parameterization data are each shown to have a substantial impact on the final potential parameterization. The analysis and critique provide the logical foundation for the different approach to the problem of parameterization and use of classical potentials that is treated in detail elsewhere in this collection. The use of extended model systems, force data calculated from QM methods, and a focused (limited) range of application are shown to be essential for a consistent (and ultimately, predictive) embedding approach to concurrent multi-scale materials simulation.     

《广石化科技》2000-2006年引文统计及分析

为研究《广石化科技》引文的引用规律，运用文献计量学原理和引文分析方法，统计分析了2000-2006年该刊刊载的438篇文章所引用的1258条参考文献。引文率为74．20％，篇均引文量为4．18条，主要的引文类型为期刊和图书，引文语种以中文为主、英文为辅，普赖斯指数为46．34％。统计结果对提高该刊的办刊质量具有一定的参考价值。     

保护东滩湿地爱护绿色家园

湿地是地球上具有高度多样性的独特生态系,它与海洋、森林并列为世界三大生态系。它具有季节或常年积水、生长和栖息喜湿植物、动物和土壤发生熟化3个基本特征。根据1971年2月在伊朗拉姆萨尔签署的《湿地     

被动方桩土拱效应三维有限元分析

基于大型有限元软件包ADINA,建立模拟被动方桩的三维有限元模型,对在桩顶边界条件和桩土接触变化时桩基的不同性状进行分析:包括土拱效应机理,桩土间的成拱效应,桩身挠度与表面荷载的变化规律以及桩侧土压力、桩身轴力的变化规律。分析结果表明,黏性土地基在邻近堆载作用下,桩身挠度与表面荷载呈非线性关系,可以用三折线模型来模拟;桩顶自由时,桩前土压力介于朗肯主动土压力与被动土压力间,呈非线性分布;在同种土中,桩侧极限土压力沿桩身呈线性分布,但比Ito理论和沈珠江理论都小。     

级联型多电平逆变器的空间矢量控制

针对级联型多电平逆变器,提出了一种高性能的空间矢量控制方法。这种方法基于空间矢量理论确定与参考电压矢量误差最小的电压矢量,它能够在接近基频的开关频率下输出接近正弦波的电压。仿真结果证实了空间矢量控制所具有的一系列显著优点。     

阵列光束在湍流大气中传输的光强闪烁研究进展

相比单束光,阵列光束由于各光束之间互不相干,可以减小大气湍流引起的接收光强起伏。特别在激光照明和通信等应用场合中,非相干合成光束可以明显提高照明均匀性和减小通信误码率。简要介绍了相干合成阵列光束在湍流大气中传输的光强闪烁研究进展。针对非相干合成阵列光束在减小光强闪烁的优势,回顾了非相干合成阵列光束在激光主动照明、星地激光大气通信方面的实验研究结果;详细总结了子光束为不同类型的非相干合成阵列光束的理论研究方法和结果,包括不同波长光、基模高斯光、部分相干高斯光和艾里光。实际中子光束一般为部分相干光,它们互相之间存在相干性。提出了下一步应深入开展研究的问题为阵列光束大气的光强闪烁。