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.     

Comparison of Additives in Anode:The Case of Graphene,MXene,CNTs Integration with Silicon Inside Carbon Nanofibers

Recently,graphene oxide(GO),MXene,carbon nanotubes(CNTs) have been used for compounding with other materials as anodes and cathodes to achieve excellent electrochemical properties for metal-ion batteries.However,few researches have focused on the differences between the three additives.Herein,silicon,as a typical anode,is selected to integrate with MXene,GO and CNTs in carbon nanofibers(CNFs) and form Si/MXene@CNFs,Si/GO@CNFs and Si/CNTs@CNFs,respectively.Together with the results,it can be realized that these CNFs with a significant improved performance compared with pure Si@CNFs show superiority in different aspects of electrochemical properties.Additionally,the reasons for the superiority are also discussed in this work.The addition of MXene can improve the cycle stability of the electrodes,thereby obtaining a high capacity retention rate,CNTs are favorable for the enhancement of rate performance,and the electrodes reversible capacity can be increased due to the addition of GO.Consequently,the studies on three additives may contribute to the rational design of silicon-based and other anode materials.     

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     

单芯大截面电缆施工设计剖析

通过一个变电所工程投运后，电缆间产生较大的感应电流，造成不能正常供电运行，论述如何从理论和实践方面分析原因，采取措施，消除不正常现象。同时，也指出单芯大截面电缆施工设计中应注意的事项。     

The effects of wall roughness on the methane flow in nano-channels using non-equilibrium multiscale molecular dynamics simulation

This paper presents a non-equilibrium multiscale molecular dynamics simulation method to investigate the effects of periodic wall surface roughness on the structure and mass transfer of methane fluid through the silicon nano-channels. In order to accurately capture the trajectories and microstructure of methane nano-fluidics, the present modification of OPLS fully atomic model is employed. Meanwhile, we introduce the corresponding coarse-grained model to solve the problem of wall–fluid interaction for methane Poiseuille flow within silicon atomic walls using the classical Lorentz–Berthelot mixing rules. The geometries of the upper wall roughness are modeled by rectangular waves with different amplitudes and wavelengths. The three-dimensional number densities of C (H) atom and kinetic energy distribution plots give a clear observation of the impacts of surface roughness on the localization micro-information of methane fluid. Moreover, the slip length of fluid over rough surface decreases with the increase in amplitude. The diffusion coefficients appear anisotropic, and the radial distribution functions decrease with the increase in the amplitude. These properties should be taken into account in the design of energy-saving emission reduction nano-fluidic devices. All numerical results also indicate that the presented method not only can well solve the issue of wall–fluid interactions, but also could accurately predict the micro-information and dynamic properties of methane Poiseuille flow.