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Building Simulation 2021年第4期14卷 1295-1309页

作者： Ri Na zhigang shen Department of Civil and Environmental Engineering University of DelawareNewarkDE19716USA The Durham School of Architecture Engineering and Construction University of Nebraska LincolnLincolnNE68588USA

A major roadblock in achieving substantial building energy reduction is the low performance of old buildings that account for a significant portion of the building energy *** low-cost energy retrofit solutions that do not disrupt occupants’daily life during the retrofitting is the key to successful building energy retrofit *** this paper,a novel and low-cost exterior wall retrofitting solution is introduced,and its performance in reducing space cooling load was quantitatively evaluated to demonstrate its feasibility and *** primary goal of this paper is to provide a quantitative assessment of the cooling-energy savings potential by using the proposed new wall *** intended retrofitting targets are the large amount of existing cavity-wall buildings located in hot climate *** quantification of the before-after heat-flux reduction was conducted through a 3-dimensional steady-state low turbulence computational fluid dynamics(CFD)model,which is validated by benchmarking its prediction against the published experimental case *** outcomes of the investigation suggest that this simple low-cost solution has great potentials in reducing buildings’summer cooling load in hot climate *** applicability of this solution is not limited to retrofitting existing *** energy-efficient building designs can also adopt this solution in their envelope systems.

关键词： low-cost energy retrofit building envelope cavity wall stack effect space cooling energy reduction CFD

Extraction Fuzzy Linguistic Rules from Neural Networks for Maximizing Tool Life in High-speed Milling Process

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Chinese Journal of Mechanical Engineering 2009年第3期22卷 341-346页

作者： shen zhigang HE Ning LI Liang College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

In metal cutting industry it is a common practice to search for optimal combination of cutting parameters in order to maximize the tool life for a fixed minimum value of material removal rate（MRR）. After the advent of high-speed milling（HSM） pro cess, lots of experimental and theoretical researches have been done for this purpose which mainly emphasized on the optimization of the cutting parameters. It is highly beneficial to convert raw data into a comprehensive knowledge-based expert system using fuzzy logic as the reasoning mechanism. In this paper an attempt has been presented for the extraction of the rules from fuzzy neural network（FNN） so as to have the most effective knowledge-base for given set of data. Experiments were conducted to determine the best values of cutting speeds that can maximize tool life for different combinations of input parameters. A fuzzy neural network was constructed based on the fuzzification of input parameters and the cutting speed. After training process, raw rule sets were extracted and a rule pruning approach was proposed to obtain concise linguistic rules. The estimation process with fuzzy inference showed that the optimized combination of fuzzy rules provided the estimation error of only 6.34 m/min as compared to 314 m/min of that of randomized combination of rule s.

关键词： high-speed milling rule extraction neural network fuzzy logic

Coating metals on micropowders by magnetron sputtering

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China Particuology 2007年第5期5卷 345-350页

作者： Zheng Xu Xiaozheng Yu zhigang shen National Engineering Laboratory of Biohydrometallurgy General Research Institute for Nonferrous Metals Beijing 100088 China Beijing Key Laboratory for Powder Technology R. & D. Beijing University of Aeronautics andAstronautics Beijing 100083 China

Magnetron sputtering was used to coat various metals on micropowder surfaces. By using this method, the fine particles are better dispersed and can therefore be coated more homogeneously. The micro-powders used include cenospheres from fly ash of coal-burning electric power plants （diameter 40-200 μm and particle density 0.7 ± 0.1 g/cm^3）, as well as carborundum particles of different sizes. Aluminum, silver, copper, cobalt and nickel were used as the coating metals. Tests showed that the coated metal film was compact adhering tightly on the base powders, and the coated powders possess adequate flow properties.

关键词： Micropowder magnetron sputter Metal coating

Characteristic comparison of metal films coated onto the cenosphere by chemical and magnetron sputtering methods

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Rare Metals 2007年第6期26卷 617-624页

作者： XU Zheng YU Xiaozheng CAI Chujiang shen zhigang General Research Institute For Nonferrous Metals Beijing 100088 China Beijing Key Laboratory for Powder Technology R ＆ D Beijing University of Aeronautics and Astronautics Beijing 100083 China

Metal-coated cenospheres have been widely used in industries. Different coating methods result in different characteristic metal films. The metal film on the cenosphere by chemical coating does not appear to be very smooth, exhibiting metal piled up and pin holes on the surface and leaving some spots uncoated. Meanwhile, the metal film is not tightly absorbed onto cenospheres and is easy to peel off. However, the metal film prepared by magnetron sputtering is compact, smooth and without pin holes. The film has good affinity to the cenosphere surface. Such films do not separate with it even when the cenosphere is crushed. Both the metal t＇rims give the same XRD patterns, indicating that the crystal structure of the metal films by these two methods is the same. Chemical coating is a complex process and harmful to the environment, but it fits ultrafine powder coating （the particle size can be less than 2 μm）. The magnetron sputtering method is environmental friendly and works quickly, but this method requires specially designed equipment and does not work for ultrafine powders. If the particle size is less than 30 μm, the coating process is hard to carry on.

关键词： coating magnetron sputtering chemical coating cenosphere

A fluid dynamics route for producing graphene and its analogues

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Chinese Science Bulletin 2014年第16期59卷 1794-1799页

作者： Min Yi zhigang shen Jinyang Zhu Beijing Key Laboratory for Powder Technology Research & Development Beijing University of Aeronautics and Astronautics Ministry-of-Education Key Laboratory of Fluid Mechanics Beijing University of Aeronautics and Astronautics State Key Laboratory for Turbulence & Complex Systems Peking University

A novel fluid dynamics route for scalable and efficient production of graphene and its analogues is *** force microscopy and transmission electron microscopy analyses strongly suggest that the bulk layered materials(graphite,BN,MoS2,and WS2)are efficiently exfoliated into individual layers containing mono-and few-layer *** fluid dynamics analysis indicates that multiple fluid dynamics events are responsible for efficient *** and pressure release can generate normal force for *** velocity gradient-induced viscous shear stress,the turbulence-induced Reynolds shear stress,and shear effects stemmed from turbulence and flow channel-induced collisions can generate lateral force for exfoliation,resulting in theses bulk layered materials self-exfoliation down to single or few layers through their intrinsically lateral self-lubricating ability.

关键词：流体动力学类似物石墨生产透射电子显微镜分析原子力显微镜层状材料剪切应力

Multidimensional reconciliation protocol for continuous-variable quantum key agreement with polar coding

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Science China(Physics,Mechanics & Astronomy) 2018年第9期61卷 99-102页

作者： shengMei Zhao zhigang shen Hong Xiao Le Wang Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education

Continuous-variable quantum key distribution（CVQKD）[1-7]allows two remote parties（Alice and Bob）to share a secret key,even in the presence of an eavesdropper（Eve）with unlimited computational power[8-17].While,a highly efficient reconciliation protocol[18-21]is crucial in a CVQKDsystem, which can not only extract the errorless secret keys, but also provide a promising way to achieve a long distance CVQKD at a low signal-to-noise ratio （SNR）.

关键词：和解协议连续变量钥匙多维编码 SNR 长距离

Efficient Synthesis of Functionalized Benzimidazoles and Perimidines： Ytterbium Chloride Catalyzed CmC Bond Cleavage

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Chinese Journal of Chemistry 2011年第9期29卷 1880-1886页

作者： Cai, Lijian Ji, Xiaofeng Yao, zhigang Xu, Fan shen, Qi Key Laboratory of Organic Synthesis College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China

An efficient method is developed for the synthesis of functionalized benzimidazoles and perimidines by the condensation of aryl diamines with β-carbonyl compounds catalyzed by ytterbium chloride. The reactions give g... 详细信息

关键词： lanthanide C--C activation catalysis ytterbium chloride benzimidazole perimidine

Controllable precipitation of naproxen micro-particles with different morphologies

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Particuology 2012年第5期10卷 634-643页

作者： Peng Cheng KangkangJin Jing Cheng Fang Yang zhigang shen Jianfeng Chen Lixiong Wen State Key Laboratory of Organic-lnorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Research Center of the Ministry of Education for High Gravity Engineering&Technology Beijing University of Chemical TechnologyBeijing 100029China

A simple precipitation method was proposed to prepare naproxen micro-particles with different controllable morphologies, using capillary video microscopy to study the precipitation process. Different particle shapes were obtained including spherical, platelet-like, stick-like, needle-like, and butterfly-like, all in the micro-size range. It was found that the sizes and morphologies of the formed naproxen particles were sensitive to the nature and concentration of the added surfactant, and depended significantly on processing conditions such as temperature, stirring speed, and initial drug concentration. In addition, pre- cipitation with different surfactant types and concentrations would not affect the crystal microstructure of the formed nanroxen oarticles.

关键词： PrecipitationCrystal growthNaproxenSurfactants

Efficient synthesis of functionalized 2-pyridones by ytterbium chloride catalyzed tandem condensation

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Chinese Science Bulletin 2012年第14期57卷 1612-1615页

作者： WANG QianNan YAO zhigang XU Fan shen Qi Key Laboratory of Organic Synthesis College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123China

An efficient method was developed for the synthesis of arylidene heterobicyclic 3-cyano-2-pyridones via ytterbium chloride catalyzed tandem condensation of aromatic aldehydes,cyclic ketones,and *** conditions and scop... 详细信息

关键词：高效合成氯化物吡啶串联催化冷凝镱反应机制

Experimental study on a designed jet cavitation device for producing two-dimensional nanosheets

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Science China(Technological Sciences) 2012年第10期55卷 2815-2819页

作者： LI JinZhi YI Min shen zhigang MA ShuLin ZHANG XiaoJing XING YuShan Beijing Key Lab.for Powder Technology Research&Development Beijing University of Aeronautics and AstronauticsBeijing 100191China

In this study,a jet cavitation device aimed at producing two-dimensional nanosheets was *** effects of cavitation generator type and jet pressure on the cavitation inception and intensity were examined by monitoring the changes of sound pressure level(SPL).As such,the optimized cavitation generator with the best cavitation capability under the same ambient condition was ***,BN and MoS 2,two kinds of layered materials,were exfoliated into individual flakes in aqueous solutions by this jet cavitation *** investigating the morphology of these exfoliated flakes via scanning electron microscopy and transmission electron microscope,it was found that these pristine materials were mostly exfoliated into two-dimensional nanosheets,among which even monolayers were generally *** exfoliation process happened mainly due to the cavitation-induced intensive tensile stress acting on the layered *** graphene has been produced by this device successfully,it is anticipated that this jet cavitation device is suitable for producing other various two-dimensional nanosheets.

关键词： jet cavitation device cavitation generator sound pressure level two-dimensional nanosheet characterization