检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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

Lithium cation-doped tungsten oxide as a bidirectional nanocatalyst for lithium-sulfur batteries with high areal capacity

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第11期98卷 406-413页

作者： Biying Wang Ke Chen Jieying Liang Zhichun yu Da-wei Wang Ruopian Fang School of Chemical Engineering The University of New South WalesSydneyNSW 2052Australia Faculty of Materials Science and Energy Engineering Shenzhen University of Advanced TechnologyShenzhen 518055GuangdongChina Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055GuangdongChina

Lithium-sulfur(Li-S) batteries are promising for high energy-storage applications but suffer from sluggish conversion reaction kinetics and substantial lithium sulfide(Li_(2)S) oxidation barrier,especially under high sulfur ***,we report a Li cation-doped tungsten oxide(Li_(x)WO_(x)) electrocatalyst that efficiently accelerates the S■HLi_(2)S interconversion *** incorporation of Li dopants into WO_(x) cationic vacancies enables bidirectional electrocatalytic activity for both polysulfide reduction and Li_(2)S oxidation,along with enhanced Li^(+) *** conjunction with theoretical calculations,it is discovered that the improved electrocatalytic activity originates from the Li dopant-induced geometric and electronic structural optimization of the Li_(x)WO_(x),which promotes the anchoring of sulfur species at favourable adsorption sites while facilitating the charge transfer ***,Li-S cells with the Li_(x)WO_(x) bidirectional electrocatalyst show stable cycling performance and high sulfur utilization under high sulfur *** approach provides insights into cation engineering as an effective electrocatalyst design strategy for advancing high-performance Li-S batteries.

关键词： Cation engineering Electrocatalysis Polysulfide conversion Lithium sulfide oxidation Lithium-sulfur batteries

Synthesis of 6E-Geranylgeraniol-19-oic Acid

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2003年第3期19卷 294-296页

作者： LI Shu hua PENG Li Zeng LI wei dong LI yu lin National Laboratory of Applied Organic Chemistry and Institute of Organic Chemistry Lanzhou UniversityLanzhou 730000P.R.China

The present paper deals with the facile synthesis of 6 E geranylgeraniol 19 oic acid(1), a naturally occuring alicyclic diterpene acid, by a Horner Wadsworth Emmons olefination of two readily available fragments 7 and 3.

关键词： Horner Wadsworth Emmons reaction 6E-Geranylgeraniol-19-oic acid Synthesis

Desilication kinetics of calcined boron mud in molten sodium hydroxide media

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2016年第9期23卷 2191-2198页

作者： NING Zhi-qiang SONG Qiu-shi ZHAI yu-chun XIE Hong-wei yu Kai School of Materials and Metallurgy Northeastern University Shenyang 110004 China

Desilication kinetics of calcined boron mud(CBM) occurring in molten sodium hydroxide media was investigated. The effects of factors such as reaction temperature and Na OH-to-CBM mass ratio on silicon extraction efficiency were studied. The results show that silicon extraction efficiency increases with increasing the reaction time and Na OH-to-CBM mass ratio. There are two stages for the desilication process of the calcined boron mud. The overall desilication process follows the shrinking-core model, and the first and second stages of the process were determined to obey the shrinking-core model for surface chemical reaction and the diffusion through the product layer, respectively. The activation energies of the first and second stages were calculated to be 44.78 k J/mol and 15.94 k J/mol, respectively.

关键词： boron mud sodium hydroxide silicon dioxide kinetics desilication

Sol-Gel Template Synthesis and Photocatalytic Activity of TiO_2 Nanofibrils Loaded on Al_2O_3 Template

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2002年第11期13卷 1115-1118页

作者： yuan GAO wei yu Meng Ke LI Hu Lin LI Department of Chemistry Lanzhou UniversityLanzhou 730000

TiO2 nanofibrils were prepared within the pores of alumina template membrane by use of sol-gel chemistry. The TiO2 nanofibrils have good crystallinity and size. There is agglomeration free among the particulates of ... 详细信息

关键词： TiO2 nanofibrils photocatalysis template-synthesis method.

Realizing Zinc Blende GaAs/AlGaAs Axial and Radial Heterostructure Nanowires by Tuning the Growth Temperature

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第6期27卷 507-512页

作者： Jingwei Cuo Hui Huang Xiaomin Ren xin Yan Shiwei Cai wei Wang Yongqing Huang Qi Wang and Xi Zhang Key Laboratory of Information Photonics & Optical Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

Vertical zinc blende GaAs/AlGaAs heterostructure nanowires were grown at different temperatures by metalorganic chemical vapor deposition via Au-assisted vapor-liquid-solid *** was found that radial growth can be enhanced by increasing the growth *** growth of radial heterostructure can be realized at temperature higher than 500℃,while the growth temperature of axial heterostructure is lower than 440℃.The room temperature photoluminescence properties of the nanowires were investigated and the relevant growth mechanism was discussed.

关键词： Nanowire GaAs AlGaAs Heterostructure Zinc blende

NUMERICAL SOLUTION OF 2D FLOW USING A LOCAL COORDINATE SYSTEM

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1999年第3期11卷 98-104页

作者： wei Wen li, Wang De yi, Liu yu ling, Tan Li xin Xi′an University of Technology, Xi′an 710048, P.R.China (Receied Nov.30,1998)

This paper is concerned with a new numerical method of two dimensional flow. The governing system of differential equations is transformed into an equivalent system applied over a square grid network in order to overcome the difficulties and inaccurancies associated with the determination of characteristics near the flow boundaries. The MacCormack two step explicit scheme with second order accurancy is used for the solution of the transformed system of equations. Comparison between computed and experimental data shows a satisfactory agreement.

关键词： unsteady 2D flow MacCormack scheme local coordinate system isoparametric element

A Model Study of Equation of State of QCD at Finite Chemical Potential and Zero Temperature

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第3期51卷 499-505页

作者： HOU Feng-Yao JIANG yu SUN wei-Min ZONG Hong-Shi Department of Physics Nanjing University Nanjing 210093 China Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100080 China joint Center for Particle Nuclear Physics and Cosmology Nanjing 210093 China

In this paper, we give a direct method for calculating the partition function, and hence the equation of state （EOS） of QCD at finite chemical potential and zero temperature. In the EOS derived in this paper the pressure density is the sum of two terms： the first term P（μ）｜μ=0 （the pressure density at μ = 0） is a μ-independent constant; the second term, which is totally determined by G[μ] （p）（the dressed quark propagator at finite μ）, contains all the nontrivial μ-dependence. By applying a general result in the rainbow-ladder approximation of the Dyson-Schwinger approach obtained in our previous study [Phys. Rev. C 71 （2005） 015205], G[μ]（p） is calculated from the meromorphic quark propagator proposed in [Phys. Rev. D 67 （2003） 054019]. From this the full analytic expression of the EOS of QCD at finite μ and zero T is obtained （apart from the constant term P（μ）｜μ=0, which can in principle be caJculated from the CJT effective action）. A comparison between our EOS and the cold, perturbative EOS of QCD of Fraga, Pisarski and Schaffner-Bielich is made. It is expected that our EOS can provide a possible new approach for the study of neutron stars.

关键词： equation of state (EOS) phase transition QCD

Effects of 14 Single Herbs on the Induction of Caspase-3 in Tumor Cells： A Brief Review

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2013年第8期19卷 636-640页

作者： Hong-yan Tian 田洪艳 (11539) Zhi-xin Li 李质馨 (11539) Hong-yu Li 李宏宇 (11539) Hong-jun Wang 王弘珺 (11539) xin-wei Zhu 朱辛为 (11539) Zhao-hua Dou 窦肇华 (11539) 11539. Department of Histology and Embryology Jilin Medical College Jilin Jilin Province 132013 China

Chinese medicines （CMs） are increasingly being used for the treatment of tumors because of their unique advantages. The induction of tumor cell apoptosis is an important method of tumor treatment. Caspase-3 is a member of the caspase （cysteine aspartic proteinases） family of enzymes, which are the major inducers of apoptosis. Caspase-3 activity is often measured in the context of research into anti-tumor drugs that target apoptosis. Many studies have shown that CMs upreguiate the expression of caspase-3 in tumor cells via extrinsic and/or intrinsic pathways, removing endogenous suppression of apoptosis and promoting tumor cell death. Therefore, several CMs fulfill the criteria for anti-tumor drugs. In this paper, we review the efficacy of 14 Chinese herbal medicines, across a wide range applications, and discuss their effects on caspase-3 activity in tumor cells.

关键词： Chinese herbal medicines tumor cells apoptosis caspase-3