Preparation of WO_3 thin films by dip film-drawing for photoelectrochemical performance

Here we report the WO_3 thin films on F-doped SnO_2 conducting glass(FTO) substrates which were prepared by using dip film-drawing method. Dip film-drawing was a simple, convenient, economical method and in largescale to prepare photoanodes for future applications. The FTO substrates were dipped in tungstic acid solution then film-drawn included 3, 6, 9, 12 and 15 times for prepared different thicknesses of WO_3 thin film photoanodes. Then the photoanodes were employed as the electrodes in photoelectrochemical property measurements, which include scan linear sweep, repeated on/off illumination cycles, electrochemical impedance spectroscopy and incident photon to current conversion efficiency, respectively. The results showed that the WO_3 thin films dipped 9 times with 175 nm thicknesses had the best photoelectrochemical performance of 0.067 mA·cm~/(-2) at 1.23 V versus RHE.     

连续催化重整装置大型化探讨

根据连续催化重整（简称连续重整）技术的发展趋势,首先从原料供应和产品需求方面分析连续重整装置大型化的需求,然后对比分析不同规模的连续重整装置在反应器设置、反应器内构件选择、加热炉布置、压缩机选型、催化剂再生工艺和节能的规模效益等方面的差异,提出规划设计大型化连续重整装置时需要注意的要素。同时针对当前连续重整工艺的发展,提出优化重整工艺的设想。     

Study of a Jacobian-free approach in the simulation of compressible fluid flows in porous media using a derivative-free spectral method

The development of Jacobian-free software for solving problems formulated by nonlinear partial differential equations is of increasing interest to simulate practical engineering processes. For the first time, this work uses the so-called derivative-free spectral algorithm for nonlinear equations in the simulation of flows in porous media. The model considered here is the one employed to describe the displacement of miscible compressible fluid in porous media with point sources and sinks, where the density of the fluid mixture varies exponentially with the pressure. This spectral algorithm is a modern method for solving large-scale nonlinear systems, which does not use any explicit information associated with the Jacobin matrix of the considered system, being a Jacobian-free approach. Two dimensional problems are presented, along with numerical results comparing the spectral algorithm to a well-developed Jacobian-free inexact Newton method. The results of this paper show that this modern spectral algorithm is a reliable and efficient method for simulation of compressible flows in porous media.     

Large-scale load capacity tests on a geosynthetic encased column

Stone columns have been used to minimize the settlement of embankments on soft soils but their use in very soft soils can become challenging, partly because of the low confinement provided by the surrounding soil. Geosynthetic encased columns (GECs) have been successfully used to enhance to reduce settlements of embankments on soft soils. This paper describes an investigation on the performance of encased columns constructed on a very soft soil using different types of encasement (three woven geotextiles with different values of tensile stiffness) and different column fill materials (sand, gravel and recycled construction and demolition waste, RCDW). The results of load capacity tests conducted on large-scale models constructed to simulate the different types of GECs indicate that the displacement method adopted during column installation can lead to an enhanced shear strength in the smear zone that develops within the very soft soil. In addition, breakage of the column fill material was found to affect the load-settlement response of gravel and RCDW columns. Furthermore, the excess pore water pressure generated in the surrounding soil during installation, was found to remain limited to radial distances smaller than three times the GEC diameter.     

大类招生背景下电子信息类专业人才培养模式的探索与思考

“大类招生、分流培养”已成为大多数高校采取的招生和培养思路，如何确定大类招生包含的专业、合理制定分流原则、制定科学的课程体系、完善相关的配套制度，不仅关系高校招生生源质量，而且影响高校人才培养质量。本文以北京交通大学电子信息工程学院为例，详细阐述了电子信息类专业人才培养模式的探索和思考。     

A quality control method by ultrasonic vibration energy and diagnosis system at trimming process

To investigate a relation between vortex clusters and large-scale structures in the outer layer of wall turbulence, direct numerical simulations of turbulent channel flows have been conducted up toRe _τ = 1270. The vortex clusters in the outer layer consist coherent fine scale eddies (CFSEs) of which diameter and maximum azimuthal velocity are scaled by the Kolmogorov length and the Kolmogorov velocity. The CFSE clusters are inside the large-scale structure, which contributes to the streamwise velocity deficit The scale of those clusters tends to be enlarged with the increase of a distance from the wall. The CFSE clusters are composed of the relatively strong CFSEs, which play an important role in the production of the Reynolds shear stress and the dissipation rate of the turbulent kinetic energy. The most expected maximum azimuthal velocity of the CFSEs in these low-momentum regions of the outer layer is 30–70% fester compared with those of the CFSEs in unconditioned regions (i.e. all regions of the outer layer), while the most expected diameter of the CFSEs is not changed greatly.     

大型活动安全风险评估系统建设研究

随着我国经济文化逐步发展,大型活动数量越来越多,规模也越来越大,其举办过程存在的安全问题也日益凸显,引起人们重视。因此有必要建立有效的安全风险评估方法事先对举办单位进行甄选,并在此基础上,利用网络通讯和应用管理平台,研究开发以接待评估活动举办过程中存在风险因素可能性和严重性的信息管理系统,供评估机构进行遴选。本文以大型活动安全评估为基本研究对象,通过阅读文献提出假设,通过调查问卷和德尔菲法分析大型活动主要风险因素,阐述建立大型活动风险因素指标体系以及信息化系统建设主要内容,为相关平台构建提供参考。     

Decentralised variable gain robust controller design for a class of large-scale interconnected systems with mismatched uncertainties

In this paper, we propose an LMI-based design method of a decentralised variable gain robust controller for large-scale interconnected systems with mismatched uncertainties. The mismatched uncertainties under consideration are composed of the matched part and the mismatched one, and the proposed decentralised robust controller consists of a state feedback with a fixed gain and one with a variable gain tuned by parameter adjustment laws. Sufficient conditions for the existence of the proposed decentralised variable gain robust controller are given in terms of linear matrix inequalities (LMIs). Finally, a numerical example is illustrated to validate the proposed design procedure.     

大型泵站的技术改造

文章根据驷马山一级站技术改造情况,探讨大型泵站技术改造对策。