既有框架结构加固中隔震技术的应用解析

由于既有框架结构加固的需要，本文首先对加固技术的应用现状进行了分析，之后对隔震技术的具体应用采取了分步论述，希望对现阶段既有建筑物加固具有参考价值。     

基于空间扩散模型的重金属污染源位置的研究

基于GIS软件ArcMap对研究区域内的重金属元素浓度的空间分布进行可视化分析。通过设计各金属污染负荷指数并结合Hakanson毒性模型,利用层次分析等数据挖掘方法确定重金属元素的权重,客观高效地确定不同功能区内的综合污染指数,基于具有自修正特征的迭代算法,对每种重金属元素的污染源位置进行了仿真,结果显示该反演模型是收敛的。     

Solution of laplace equation by the method of separation of variables

Abstract

The Laplace equation, which is used to describe the problem of two‐dimensional heat conduction with appropriate boundary conditions at steady state, is solved in this work by applying the method of separation of variables. The primary objective of this work involves discussing the effects of the constant value of the separation of variables (p) and the sequential order of substituting boundary conditions on the solution. Without appropriately arranging the sequential order of substituting the boundary conditions, the solution for non‐zero constant values of separation of variables (p) can not be obtained. For a zero value for the constant of the separation of variables, the solution obtained is trivial or does not exist. Solutions in different forms are obtained by using different values for the constant of the separation of variables (p) and for the sequential orders of substituting the boundary conditions.     

Performance analysis of multi‐antenna relay communication systems with MRC

The performance of multi‐antenna relay communication systems is investigated in this letter. The source broadcasts the signal to all the relays and the destination. Decode‐and‐forward scheme is adopted at the relays, and the destination employs maximum ratio combining (MRC) technique to maximize the received signal‐to‐noise ratio. Closed‐form expressions of outage probability are derived in the MRC case and minimum routes MRC case. An adaptive grouping algorithm of relay antennas is also presented under the constraint of total antenna number. Simulation results show that the analytical curves agree with the simulated ones very well, and the performance of the proposed grouping algorithm is very close to the upper bound mentioned in other papers. Copyright © 2012 John Wiley & Sons, Ltd.     

Designing and evaluating business process models: an experimental approach

This paper presents an experimental approach to compare the performance of alternative business process designs. We use an example case of an electronic group buying setting to demonstrate how our approach can be applied in practice. More specifically, we chose a standard business process, the sales process as implemented on a group buying platform, to illustrate how a business process may be redesigned in order to better meet the needs of customers. For that purpose, we introduce a social technology feature to support cooperation among buyers in the sales process and then analyze the performance impact of the proposed business process redesign. We combine principles from design science and experimental economics to aid the business redesign process. To allow for an experimental evaluation in a controlled laboratory setting, we implement a simplified prototype model and an experimental electronic group-buying platform in the laboratory. We then employ the methods of experimental economics to generate process performance data and evaluate the effectiveness of the new process model design in the lab that can provide valuable insights to platform managers for redesigning the real-world system. We posit that combining the principles of design science and experimental economics offers researchers a useful and cost-effective method to systematically evaluate theoretical predictions about process model design.     

Design of an Ultrafast G Protein Switch Based on a Mouse Melanopsin Variant

The primary goal of optogenetics is the light-controlled noninvasive and specific manipulation of various cellular processes. Herein, we present a hybrid strategy for targeted protein engineering combining computational techniques with electrophysiological and UV/visible spectroscopic experiments. We validated our concept for channelrhodopsin-2 and applied it to modify the less-well-studied vertebrate opsin melanopsin. Melanopsin is a promising optogenetic tool that functions as a selective molecular light switch for G protein-coupled receptor pathways. Thus, we constructed a model of the melanopsin G_q protein complex and predicted an absorption maximum shift of the Y211F variant. This variant displays a narrow blue-shifted action spectrum and twofold faster deactivation kinetics compared to wild-type melanopsin on G protein-coupled inward rectifying K⁺ (GIRK) channels in HEK293 cells. Furthermore, we verified the in vivo activity and optogenetic potential for the variant in mice. Thus, we propose that our developed concept will be generally applicable to designing optogenetic tools.     

Effects of different nut oils on the structures and properties of gel-like emulsions induced by ultrasound using soy protein as an emulsifier

Gel-like emulsions were produced by high-intensity ultrasound (HIU) emulsification using soy protein as an emulsifier. Sunflower (a seed kernel oil), peanut (a groundnut oil), hazelnut, walnut, almond and pine nut oils were chosen as oil phases. The kinds of nut oil significantly affect the structures and properties of gel-like emulsions. The particle size of sunflower oil gel-like emulsion was smallest. Moreover, the macrorheological and microrheological results indicated that the values of apparent viscosity, storage modulus (G′) and elasticity index (EI) of sunflower and almond oil gel-like emulsions were higher while those of the walnut and pine nut oil gel-like emulsions were lower. Moreover, the sunflower oil gel-like emulsion was more stable after 2-month storage. The current study illustrated that HIU was of great importance for the production of high-viscosity gel-like emulsions. Furthermore, the differences of nut oils resulted in diverse physicochemical properties of gel-like emulsions.     

生态型村落污水治理及再利用方案研究

通过对昌平区3个村落污水水质的监测,结合当地自然条件及发展现状,最终确定将SBR工艺+水生植物塘工艺作为该3个村的污水处理工艺,建设相应的村级污水处理站,降低污水随意排放带来的生态污染,充分利用再生水,节约地下水资源,达到了改善、美化村落环境的目的。     

Nanoporous Surface High-Entropy Alloys as Highly Efficient Multisite Electrocatalysts for Nonacidic Hydrogen Evolution Reaction

Electrocatalytic hydrogen evolution in alkaline and neutral media offers the possibility of adopting platinum-free electrocatalysts for large-scale electrochemical production of pure hydrogen fuel, but most state-of-the-art electrocatalytic materials based on nonprecious transition metals operate at high overpotentials. Here, a monolithic nanoporous multielemental CuAlNiMoFe electrode with electroactive high-entropy CuNiMoFe surface is reported to hold great promise as cost-effective electrocatalyst for hydrogen evolution reaction (HER) in alkaline and neutral media. By virtue of a surface high-entropy alloy composed of dissimilar Cu, Ni, Mo, and Fe metals offering bifunctional electrocatalytic sites with enhanced kinetics for water dissociation and adsorption/desorption of reactive hydrogen intermediates, and hierarchical nanoporous Cu scaffold facilitating electron transfer/mass transport, the nanoporous CuAlNiMoFe electrode exhibits superior nonacidic HER electrocatalysis. It only takes overpotentials as low as ≈240 and ≈183 mV to reach current densities of ≈1840 and ≈100 mA cm⁻² in 1 m  KOH and pH 7 buffer electrolytes, respectively; ≈46- and ≈14-fold higher than those of ternary CuAlNi electrode with bimetallic Cu–Ni surface alloy. The outstanding electrocatalytic properties make nonprecious multielemental alloys attractive candidates as high-performance nonacidic HER electrocatalytic electrodes in water electrolysis.