检索结果-南通市图书馆

A BLOCK-CENTERED UPWIND APPROXIMATION OF THE SEMICONDUCTOR DEVICE PROBLEM ON A DYNAMICALLY CHANGING MESH

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2020年第5期40卷 1405-1428页

作者： Yirang YUAN changfeng li Huailing SONG Institute of Mathematics Shandong UniversityJinan 250100China Shandong Applied Financial Theory and Policy Research Base Jinan 250100China School of Economics Shandong UniversityJinan 250100China College of Mathematics and Econometrics Hunan UniversityChangsha 410082China

The numerical simulation of a three-dimensional semiconductor device is a fundamental problem in information science. The mathematical model is defined by an initialboundary nonlinear system of four partial differential equations: an elliptic equation for electric potential, two convection-diffusion equations for electron concentration and hole concentration, and a heat conduction equation for temperature. The first equation is solved by the conservative block-centered method. The concentrations and temperature are computed by the block-centered upwind difference method on a changing mesh, where the block-centered method and upwind approximation are used to discretize the diffusion and convection, respectively. The computations on a changing mesh show very well the local special properties nearby the P-N junction. The upwind scheme is applied to approximate the convection, and numerical dispersion and nonphysical oscillation are avoided. The block-centered difference computes concentrations, temperature, and their adjoint vector functions *** local conservation of mass, an important rule in the numerical simulation of a semiconductor device, is preserved during the computations. An optimal order convergence is obtained. Numerical examples are provided to show efficiency and application.

关键词： three-dimensional semiconductor device of heat conduction block-centered upwind difference on a changing mesh local conservation of mass convergence analysis numerical computation

An Upwind Mixed Volume Element-Fractional Step Method on a Changing Mesh for Compressible Contamination Treatment from Nuclear Waste

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2018年第6期10卷 1384-1417页

作者： changfeng li Yirang Yuan Huailing Song Institute of Mathematics Shandong UniversityJinan 250100China School of Economics Shandong UniversityJinan 250100China College of Mathematics and Econometrics Hunan UniversityChangsha 410082China

In this paper the authors discuss the numerical simulation problem of threedimensional compressible contamination treatment from nuclear *** mathematical model is defined by an initial-boundary nonlinear convection-diffusion system of four partial differential equations:a parabolic equation for the pressure,two convection-diffusion equations for the concentrations of brine and radionuclide and a heat conduction equation for the *** pressure appears within the concentration equations and heat conduction equation,and the Darcy velocity controls the concentrations and the *** pressure is solved by the conservative mixed volume element method,and the order of the accuracy is improved by the Darcy *** concentration of brine and temperature are computed by the upwind mixed volume element method on a changing mesh,where the diffusion is discretized by a mixed volume element and the convection is treated by an upwind *** composite method can solve the convection-dominated diffusion problems well because it eliminates numerical dispersion and nonphysical oscillation and has high order computational *** mixed volume element has the local conservation of mass and energy,and it can obtain the brine and temperature and their adjoint vector functions *** conservation nature plays an important role in numerical simulation of underground *** concentrations of radionuclide factors are solved by the method of upwind fractional step difference and the computational work is decreased by decomposing a three-dimensional problem into three successive one-dimensional problems and using the method of *** the theory and technique of a priori estimates of differential equations,we derive an optimal order result in L^(2) *** examples are given to show the effectiveness and practicability and the composite method is testified as a powerful tool to solve the well-known actual problem.

关键词： Compressible nuclear waste contamination in porous media upwind mixed volume element-fractional step on a changing mesh conservation of mass and energy convergence analysis numerical example

Electrochemical Immunoassay of E. coil in Urban Sludge Using Electron Mediator-mediated Enzymatic Catalysis and Gold Nanoparticles for Signal Amplification

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2018年第1期34卷 101-106页

作者： LU Wenjie XU Rongjin ZHANG Xinai SHEN Jianzhong li changfeng School of Energy and Power Engineering Jiangsu University Zhenjiang 212013 P. R. China School of Food and Biological Engineering Jiangsu University Zhenjiang 212013 R R. China

An electrochemical immunosensor was developed for sensitive assay ofE. coli in urban sludge, in which electron mediator-mediated enzymatic catalysis and gold nanoparticles（AuNPs） were utilized for signal amplification. The immnuosensing platform chitosan-thionine（chit-thio）/poly（amidoamine） dendrimer-encapsulated AuNPs [PAMAM（Au）] composites were first prepared from chit-thio and PAMAM（Au） using the layer-by-layer method to provide a matrix for high-stability and high-bioactivity bindings of the capture antibody（cAb）. Moreover, the {dAb-AuNPs-HRP} nanoprobes were designed to exploit the amplification effect of the carrier AuNPs due to the loading amounts of horseradish peroxidase（HRP）and the detection antibody（dAb）. The sandwich-type immunoassay was then successfully used to assay E. coli based on the oxidation of thionine as a result of H2O2-induced enzymatic catalytic reaction by HRP. This study presents a powerful tool in electrochemical immunoassay for E. coli detection with rapid response, high-sensitivity and high-specificity, providing a potential new tool for feasibility assessment of sludge recycle.

关键词： Electron mediator Enzymatic catalysis Electrochemical immtmosensor E. coli Urban sludge

Assessment of Fiber Distribution in Steel Fiber Mortar Using Image Analysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2012年第1期27卷 166-171页

作者： liU Jianzhong SUN Wei MIAO Changwen liU Jiaping li changfeng Jiangsu Key Laboratory of Civil Engineering Materials Southeast University State Key Laboratory of High Performance Civil Engineering Materials Jiangsu Research Institute of Building Science

A new test method was introduced to measure fiber distribution in steel fiber reinforced mortar by using image analysis technique. Through specimen preparation, image acquisition, fiber extraction, and measurement of related fiber parameters, quantitative analysis of fiber distribution could be obtained by two parameters, namely dispersion coefficient and orientation factor. Effect of boundaries, size and steel fiber content on fiber distribution was discussed. Results showed that, steel fiber distribution was affected by boundary effect, which would be weakened with the increase of specimen size. If the length and width remained constant, the specimen height had a significant effect on orientation factor of fiber, while its influence on dispersion coefficient was not so obvious. With the increase of steel fiber content, dispersion coefficient decreased slightly, and orientation factor deviated from 0.5.

关键词： image analysis steel fiber dispersion coefficient orientation factor characterization

Determination of L-Cystine by a New Sensitive Cucurbit[7]uril/palmatine Probe

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2011年第6期29卷 1268-1272页

作者： Yang, Jiyuan Du, liming Wu, Hao Chang, Yinxia li, changfeng Analytical and Testing Center Shanxi Normal University Linfen Shanxi 041004 China

In the presence of cucurbit[7]uril （CB[7]）, the CB[7] could react with palmatine, which served as a sensitive fluorescence probe, to form host-guest stable complexes and the fluorescence intensity of the complexes was greatly enhanced. The fluorescence intensity decreased linearly with an increasing number of L-cystine in the inclusion system. The experimental results show that there exists a competition between L-cystine and palmatine for the CB[7] hydrophobic cavity and L-cystine occupies the space of CB[7] cavity, leading palmatine molecules to be forced to reside in the aqueous environment. Based on the fluorescence quenching of the CB[7]/palmatine complexes resulting from complex formation between CB[7] and L-cystine, a spectrofluorimetric method for the determination of L-cystine in aqueous solution in the presence of CB[7] was developed. The linear relationship between the corresponding values of the fluorescence quenching AF and L-cystine concentration was obtained in the range of 6.0 to 1.5 × 10^3 ngomL l, with a correlation coefficient （r） of 0.9996. The detection limit was 2.0 ng·mL -1. The application of the present method to the determination of L-cystine in tablets gave satisfactory results. This paper also discussed the mechanism of the fluorescence indicator probe.

关键词： fluorescence spectroscopy host-guest systems trace analysis L-cystine

Chlorine-Substituent Regulation in Dopant-Free Small-Molecule Hole-Transport Materials Improves the Effi ciency and Stability of Inverted Perovskite Solar Cells

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2024年第4期30卷 314-323页

作者： Xinyi liu Xiaoye Zhang Zhanfeng li Jinbo Chen Yanting Tian Baoyou liu changfeng Si Gang Yue Hua Dong Zhaoxin Wu Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceTaiyuan University of TechnologyTaiyuan 030024China School of Electrical Engineering University of South ChinaHengyang 421001China College of Physics and Optoelectronics Taiyuan University of TechnologyTaiyuan 030024China Ningxia Hui Autonomous Region Screen Display Organic Materials Engineering Technology Research Center Ningxia Sinostar Display Material Co.Ltd.Yinchuan 750003China Organic Semiconductor Centre EaStCHEM School of ChemistryUniversity of St AndrewsFife KY169STUK Key Laboratory of Photonics Technology for Information School of Electronic and Information Engineering Xi’an Jiaotong UniversityXi’an 710049China

Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the ***,we describe the use of various chlorinated small molecules,specifi cally fl uorenone-triphenylamine(FO-TPA)-x-Cl[x=para,meta,and ortho(p,m,and o)],with diff erent chlorine-substituent positions,as dopant-free HTMs for *** chlorinated molecules feature a symmetrical donor-acceptor-donor structure and ideal intramolecular charge transfer properties,allowing for self-doping and the establishment of built-in potentials for improving charge *** effi cient hole-transfer interfaces are constructed between perovskites and these HTMs by strategi-cally modifying the chlorine ***,the chlorinated HTM-derived inverted PSCs exhibited superior effi ciencies and air ***,the dopant-free HTM FO-TPA-o-Cl not only attains a power conversion effi ciency of 20.82% but also demonstrates exceptional stability,retaining 93.8%of its initial effi ciency even after a 30-day aging test conducted under ambient air conditions in PSCs without *** fi ndings underscore the critical role of chlorine-substituent regulation in HTMs in ensuring the formation and maintenance of effi cient and stable PSCs.

关键词： Hole-transport materials Inverted perovskite solar cells Chlorinated small molecules Donor–acceptor–donor structure

《民法典》时代惩罚性赔偿制度的理论重构与功能实现

在线全文

学校读者我要写书评

暂无评论

河南社会科学 2022年第1期30卷 81-88页

作者：李昌凤中共河南省委党校法学部河南郑州450046

在传统法学理论和制度体系中,惩罚性赔偿制度被视为异端邪说。然而,惩罚性赔偿制度是新时代法治中国建设中亟待发展完善的法律制度之一,其独特的威慑和惩罚功能是其他制度无法替代的。在对传统公私法二元区分理论合理扬弃、赋予民法公... 详细信息

在传统法学理论和制度体系中,惩罚性赔偿制度被视为异端邪说。然而,惩罚性赔偿制度是新时代法治中国建设中亟待发展完善的法律制度之一,其独特的威慑和惩罚功能是其他制度无法替代的。在对传统公私法二元区分理论合理扬弃、赋予民法公平原则以新的时代内涵等理论创新的基础之上,惩罚性赔偿制度不仅是合理的,而且是必要的。我国惩罚性赔偿制度的合理构建应当以《民法典》的立法精神为基本遵循,秉持审慎谦抑理念,按照有统有分、统分结合的原则,以"统"来保障惩罚性赔偿制度的和谐统一,以"分"来促进惩罚性赔偿制度焕发强大的生机活力。

关键词：惩罚性赔偿制度公私法二元区分理论理论重构功能实现审慎谦抑

Synthesis of amphiphilic peroxophosphomolybdates for oxidative desulfurization of fuels in ionic liquids

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2018年第4期15卷 890-897页

作者： Beibei Zhang Wei Jiang Xiaonan Fan Ming Zhang Yanchen Wei Jing He changfeng li Huaming li Wenshuai Zhu School of Energy and Power Engineering Jiangsu University School of Chemistry and Chemical Engineering Yancheng Institute of Technology Institute for Energy Research Jiangsu University School of Chemistry and Chemical Engineering Jiangsu University

Three amphiphilic peroxophosphomolybdates[Cmim]PMoO,[Cmim]PMoOand[Cmim]PMoOwere synthesized and *** catalysts were used for extraction and catalytic oxidative desulfurization of fuel with HOas an oxidant and ionic liquid[Cmim]BFas an *** was found that[Cmim]PMoOshowed the highest catalytic activity and the sulfur content could decrease to 7.5 *** contrast,the desulfurization system shows very low performance without HOor ionic *** detailed reaction conditions were optimized including reaction time,temperature,the dosage of HOand catalyst,and different sulfur *** the reaction,the catalysts and the ionic liquid can be cycled 8 times with a little decrease in desulfurization efficiency.

关键词： Peroxophosphomolybdate Oxidative desulfurization Ionic liquid H_2O_2

乡村振兴战略下土地经营权的法律规范表达与规制路径

在线全文

学校读者我要写书评

暂无评论

学习论坛 2022年第4期38卷 128-136页

作者：李昌凤中共河南省委党校法学教研部河南郑州450046

我国农村土地制度中的承包地“三权”分置改革是乡村振兴战略中的大文章。承包地从“两权分离”到“三权”分置的关键是土地经营权的制度设计。以承包地“三权”分置政策目标为导向,土地经营权的法律规范表达与权利运行规制必须实现理... 详细信息

我国农村土地制度中的承包地“三权”分置改革是乡村振兴战略中的大文章。承包地从“两权分离”到“三权”分置的关键是土地经营权的制度设计。以承包地“三权”分置政策目标为导向,土地经营权的法律规范表达与权利运行规制必须实现理论和实践的双重创新。从政治维度、历史维度、经济维度、法律维度等多重维度权衡,土地经营权宜定性为用益物权,这是顺应时代发展大势、符合我国改革实践需求和民事权利体系化构造并有“权利行使理论”予以理论支撑的立法选择。为实现“放活土地经营权”和土地经营权的规范有序流转,应按照“非必要不限制”的原则来设置土地经营权的流转条件,并赋予所有期限的土地经营权以登记资格。

关键词：乡村振兴战略土地经营权权利属性法律规制