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Experimental study of wind loads on gable roofs of low-rise buildings with overhangs

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Frontiers of Structural and Civil Engineering 2018年第3期12卷 300-317页

作者： Peng HUANG Ling TAO Ming GU yong quan i University Shanghai 200092China

Gable roofs with overhangs （eaves） are the common constructions of low-rise buildings on the southeastern coast of China, and they were vulnerable to typhoons from experience. The wind pressure distributions on gable roofs of low-rise buildings are investigated by a series of wind tunnel tests which consist of 99 test cases with various roof pitches, height-depth ratios and width-depth ratios. The block pressure coefficients and worst negative （block） pressure coefficients on different roof regions of low-rise buildings are proposed for the main structure and building envelope, respectively. The effects of roof pitch, height-depth ratio, and width-depth ratio on the pressure coefficients of each region are analyzed in detail. In addition, the pressure coefficients on the roofs for the main structure and building envelope are fitted according to roof pitch, height-depth ratio and width-depth ratio of the low-rise building. Meanwhile, the rationality of the fitting formulas is verified by comparing the fitting results with the codes of different countries. Lastly, the block pressure coefficients and worst negative pressure coefficients are recommended to guide the design of low-rise buildings in typhoon area and act as references for the future＇s modification of wind load codes.

关键词： low-rise building gable roof wind loads wind tunnel test block pressure coefficient load code

Application of Fourier transform ion cyclotron resonance mass spectrometry in molecular characterization of dissolved organic matter

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Science China Earth Sciences 2022年第12期65卷 2219-2236页

作者： chen HE Ding HE Chunmao chen quan SHI State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Department of Ocean Science and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) The Hong Kong University of Science and TechnologyHong Kong 999077China

Dissolved organic matter(DOM)plays an important role in the global carbon cycle,and an in-depth analysis of its chemical composition is fundamental to the study of its environmental and biogeochemical behavior and *** is a complex mixture of organic substances,and determining its molecular composition is a long-standing challenge in the field of analytical *** development and application of Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)has enabled the identification of the chemical composition of DOM at the molecular *** paper summarizes progress made in the molecular characterization of DOM based on the FT-ICR MS technique,including DOM sample pretreatment methods,mass spectrometry ionization techniques,data acquisition,data processing and presentation,and molecular structure *** on the work done by the instrument at the State Key Laboratory of Heavy Oil Processing in the China University of Petroleum,Beijing,we introduce applications of FT-ICR MS in the fields of earth science,environmental science and engineering,and look ahead to further research directions in the future.

关键词： Dissolved organic matter FT-ICR MS Molecular composition Recalcitrant dissolved organic matter High resolution mass spectrometry

Mixed nonlinear dynamic voltage phasor tracing method based on WAMS/SCADA

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第6期10卷 868-876页

作者： Xiao-gang chen yong-hui YI Wei WANG quan-yuan JIANG Chuang-xin GUO Yi-jia CAO School of Electrical Engineering Zhejiang University Hangzhou 310027 China Hangzhou Electric Power Bureau Hangzhou 310009 China Zhejiang Provincial Electric Power Company Hangzhou 310007 China

By considering the static voltage characteristic of the load, we propose a WAMS/SCADA mixed nonlinear method to estimate the voltage of unobservable buses caused by topology change or phasor measurement unit (PMU) malfunction in a power system. By modeling the load characteristic with data from SCADA, we employed the Gauss-Seidel method to solve the nonlinear equations and estimate the voltage of unobservable buses with the high precision voltages of neighboring buses measured by a PMU. Simulations were carried out on the IEEE 39-bus system, and the results show that this novel method can dynamically and accurately trace the variation of the voltage phasor of the unobservable buses.

关键词： Wide area measurement system (WAMS) Supervisory control and data acquisition (SCADA) system Observability Dynamic tracing Nonlinear equation

FAST RECONSTRUCTION METHOD BASED ON COMMON UNIFIED DEVICE ARCHITECTURE(CUDA)FOR MICRO-CT

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Journal of Innovative Optical Health Sciences 2010年第1期3卷 39-43页

作者： GUOTAO quan TANGYOU SUN yong DENG Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for Optoelectronics—Huazhong University of Science and Technology Wuhan 430074 P.R.China

Three-dimensional image reconstruction with Feldkamp,Davis,and Kress(FDK)algorithm is the most time consuming part in *** parallel algorithm based on the computer cluster is capable of accelerating image reconstruction speed;however,the hardware is very *** this paper,using the most current graphics processing units(GPU),we present a method based on common unified device architecture(CUDA)for speeding up the Micro-CT image reconstruction *** most time consuming filtering and back-projection parts of the FDK algorithm are parallelized for the CUDA *** CUDA-based reconstruction speed and image qualities are compared with CPU results for the projecting data of the Micro-CT *** results show that the 3D image reconstruction speed based on CUDA is ten times faster than the speed with *** conclusion the FDK algorithm based on CUDA for Micro-CT can reconstruct the 3D image right after the end of data acquisition.

关键词： Micro-CT FDK CUDA GPU

Variable Universe Fuzzy Control for Battery Equalization

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Journal of Systems Science & Complexity 2018年第1期31卷 325-342页

作者： ZHENG Jian chen Jian OUYANG quan The State Key Laboratory of Industrial Control Technology College of Control Science and Engineering Zhejiang University

In order to avoid the overcharge and overdischarge damages, and to improve the lifetime of the lithium-ion batteries, it is essential to keep the cell voltages in a battery pack at the same level,i.e., battery equalization. Based on the bi-directional modified Cuk converter, variable universe fuzzy controllers are proposed to adaptively maintain equalizing currents between cells of a serially connected battery pack in varying conditions. The inputs to the fuzzy controller are the voltage differences and the average voltages of adjacent cell pairs. A large voltage difference requires large equalizing current while adjacent cells both with low/high voltages can only stand small discharge/charge currents. Compared with the conventional fuzzy control method, the proposed method differs in that the universe can shrink or expand as the effects of the input changes. This is important as the input may change in a small range. Simulation results demonstrate that the proposed variable universe fuzzy control method has fast equalization speed and good adaptiveness for varying conditions.

关键词： Cell equalization lithium-ion battery variable universe fuzzy control

Modification of NASICON Electrolyte and Its Application in Real Na-Ion Cells

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Engineering 2022年第1期8卷 170-180页

作者： Qiangqiang Zhang quan Zhou Yaxiang Lu Yuanjun Shao Yuruo Qi Xingguo Qi Guiming Zhong yong Yang Liquan chen yong-Sheng Hu Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Xiamen Institute of Rare-Earth Materials Haixi InstitutesChinese Academy of SciencesXiamen 361021China State Key Laboratory of Physical Chemistry of Solid Surfaces&Department of Chemistry College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China HiNa Battery Technology Co. Ltd.Liyang 213300China Yangtze River Delta Physics Research Center Co. Ltd.Liyang 213300China

The low ionic conductivity of solid-state electrolytes(SSEs)and the inferior interfacial reliability between SSEs and solid-state electrodes are two urgent challenges hindering the application of solid-state sodium batteries(SSSBs).Herein,sodium(Na)super ionic conductor(NASICON)-type SSEs with a nominal composition of Na_(3+2x)Zr_(2-x)MgxSi_(2)PO_(12) were synthesized using a facile two-step solid-state method,among which Na_(3.3)Zr_(1.85)Mg_(0.15)Si_(2)PO_(12)(x=0.15,NZSP-Mg_(0.15))showed the highest ionic conductivity of 3.54mS∙cm^(-1) at 25℃.By means of a thorough investigation,it was verified that the composition of the grain boundary plays a crucial role in determining the total ionic conductivity of ***,due to a lack of examination in the literature regarding whether NASICON can provide enough anodic electrochemical stability to enable high-voltage SSSBs,we first adopted a high-voltage Na_(3)(VOPO_(4))2F(NVOPF)cathode to verify its compatibility with the optimized NZSP-Mg_(0.15) *** comparing the electrochemical performance of cells with different configurations(low-voltage cathode vs high-voltage cathode,liquid electrolytes vs SSEs),along with an X-ray photoelectron spectroscopy evaluation of the after-cycled NZSP-Mg_(0.15),it was demonstrated that the NASICON SSEs are not stable enough under high voltage,suggesting the importance of investigating the interface between the NASICON SSEs and high-voltage ***,by coating NZSP-Mg_(0.15) NASICON powder onto a polyethylene(PE)separator(PE@NASICON),a 2.42 A∙h non-aqueous Na-ion cell of carbon|PE@NASICON|NaNi_(2/9)Cu_(1/9)Fe_(1/3)Mn_(1/3)O_(2) was found to deliver an excellent cycling performance with an 88%capacity retention after 2000 cycles,thereby demonstrating the high reliability of SSEs with NASICON-coated separator.

关键词： Solid-state electrolytes Solid-state sodium batteries NASICON Interface Separator Coating

Research on secure buyer-seller watermarking protocol

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Journal of Systems Engineering and Electronics 2008年第2期19卷 370-376,384页

作者： Liu quan chen Zheng Zhou Zude School of Information Engineering Wuhan Univ. of Technology Wuhan 430070 P. R. China

A new buyer-seller watermarking protocol is proposed by applying a double encryption method and a novel mechanism of embedding a buyer＇s watermark. The protocol can effectively prevent against collusion attacks and the man in the middle attack if the third party is not trusted. Also, based on the proposed scheme for the first-hand transaction, a new buyer-reseller watermarking protocol and a formal multi-party watermarking protocol are also proposed. The proposed buyer-resell watermarking protocol only needs the original seller to provide transfer certificate and encryption-decryption service to support the second-hand transaction, and the multi-party watermarking protocol with distributed certificate authorities can overcome the difficulty in the combination of multicast mechanism with multiple unique watermarks and allow a seller to multicast the watermarked digital contents and key transaction information to n buyers. Furthermore, the idea of zero knowledge proof is also applied into the proposed scheme to allow the seller to take an effective control on the task performed by the third party.

关键词： watermarking protocol zero knowledge proof distributed certification authorities.

Solubility Product for CuS and Cu_2S in Iron

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Journal of Iron and Steel Research International 2010年第8期17卷 36-38页

作者： QI Hai-quan yong Qi-long Kunming University of Science and Technology Kunming 650093YunnanChina Central Iron and Steel Research Institute Beijing 100081China

The solubility product formulae of CuS and Cu2S in ferrite and in austenite have been obtained via thermodynamic method,according to the formation energy of CuS and Cu2S and the solubility formulae of elements Cu and S in ferrite and in *** comparing the solubility products for CuS and Cu2S in iron,it is found that Cu2S instead of CuS should be precipitated in iron due to competitative precipitation,in the view of *** formulae of CuS and Cu2S deduced from thermodynamic method would play an important role in related theoretical research and practical production.

关键词： CuS Cu2S solubility product ferrite austenite

Optimization of output and phosphor consumption for phosphor-converted white light-emitting diodes

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Rare Metals 2014年第2期33卷 203-209页

作者： Dong-Chuan chen quan-Lin Liu School of Materials Science & Engineering University of Science and Technology Beijing State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing

Using ray-tracing simulation based on Monte Carlo method, the effects of phosphor concentration and thickness on light output and phosphor consumption of pcwLEDs were investigated in this work. The simulation was improved to comprehensively imitate the whole optical process of pc-wLEDs, including total produce of chip and phosphor light, losses in the propagation, and *** were conducted to verify the *** show that, light output changes non-monotonously over phosphor concentration and thickness, having maximum value. Experimental maximum light efficiency of158 lmáW-1was obtained at concentration of 16 wt%, 6 %higher than that of 11 wt% and 17 % higher than that of 33wt%. Phosphor consumption of pc-wLEDs increases linearly with the increase of phosphor concentration and the decrease of thickness. Experimental phosphor consumption of pc-wLEDs with concentration of 11 wt% is only 37 %of that of 33 wt%.

关键词： pc-wLEDs Concentration Thickness Output Phosphor consumption