检索结果-南通市图书馆

A Reduced Basis Approach for Some Weakly Stochastic Multiscale Problems

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2012年第5期33卷 657-672页

作者： Claude le BRIS Florian THOMINES CERMICS Ecole Nationale des Ponts et Chaussees6 et 8 Avenue Blaise PascalCite DescartesChamps-sur-Marne77455 Marne-La-Vallée Cedex 2France INRIA Rocquencourt MICMAC teamprojectDomaine de VoluceauBP10578153 Le Chesnay CedexFrance. INRIA Rocquencourt MICMAC team-projectDomaine de VoluceauBP10578153 Le Chesnay CedexFrance Laboratoire Navier Ecole Nationale des Ponts et Chaussees6 et 8 Avenue Blaise PascalCite DescartesChamps-Sur-Marne77455 Marne-La-Vallée Cedex 2France.

In this paper,a multiscale problem arising in material science is *** problem involves a random coefficient which is assumed to be a perturbation of a deterministic coefficient,in a sense made precisely in the body of the *** homogenized limit is then computed by using a perturbation *** computation requires repeatedly solving a corrector-like equation for various configurations of the *** this purpose,the reduced basis approach is employed and adapted to the specific *** authors perform numerical tests that demonstrate the efficiency of the approach.

关键词： Reduced basis Stochastic homogenization Perturbation approach

Impact of power system network topology errors on real-time locational marginal price

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2017年第5期5卷 797-809页

作者： Dae-Hyun CHOI le XIE School of Electrical and Electronics Engineering Chung-ang UniversityDongjak-guSeoul 156-756Republic of Korea Department of Electrical and Computer Engineering Texas A&M UniversityCollege StationTXUSA

This paper examines the impact of power transmission network topology change on locational marginal price(LMP) in real-time power markets. We consider the case where the false status of circuit breakers(CBs) that bypass topology error processing can generate an incorrect power system network topology, subsequently distorting the results of the state estimation and economic *** main goal of this paper is to assess the economic impact of this misconfigured network topology on realtime LMP in an entire power system with network congestion. To this end, we start with our prior result, a simple and analytical congestion price equation, which can be applied to any single line congestion scenario. This equation can be extended to better understand the degree to which the LMP at any bus changes due to any line status error. Furthermore, it enables a rigorous analysis of the relationship between the change in LMP at any bus with respect to any line error and various physical/economical grid conditions such as the bidding prices for marginal generators and the locations of the congested/erroneous lines. Numerical examples on the impact analysis of this topology error are illustrated in IEEE 14-bus and 118-bus systems.

关键词： Power market Economic dispatch Locational marginal price Power system network topology

Carbon hollow spheres as cocatalyst of Cu-doped TiO_(2)nanoparticles for improved photocatalytic H_(2)generation

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第6期41卷 2063-2073页

作者： Li-Juan Sun Hai-Wei Su Di-Fa Xu le-le Wang Hua Tang Qin-Qin Liu School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China Hunan Key Laboratory of Applied Environmental Photocatalysis Changsha UniversityChangsha 410022China State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350108China School of Environmental Science and Engineering Qingdao UniversityQingdao 266071China

The reasonable employment of cocatalyst in photocatalysis can effectively promote the photocatalytic H_(2)production *** this study,carbon hollow spheres(C),as a good conductive nonmetallic material,have been utilized as a novel cocatalyst and a matrix for loading the Cu-doped-TiO_(2)nanoparticles by a successive hydrother-mal method and metal molten salt *** Cu-doped-TiO_(2)nanoparticles were tightly anchored on the surface of carbon hollow sphere to form a zero-dimensional/three dimensional(0D/3D)Cu-doped-TiO2/C *** optimal Cu-doped-TiO_(2)/C heterojunction demon-strated greatly enhanced photocatalytic H_(2) generation activity(14.4 mmol·g^(-1)·h^(-1))compared with TiO_(2)(0.33 mmol·g^(-1)·h^(-1))and TiO_(2)/C(0.7 mmol·g^(-1)·h^(-1)).The performance improvement was mainly due to the syner-gistic effect of carbon hollow sphere cocatalyst and Cu-doping,the Cu-doping in TiO_(2)nanoparticles can minimize charge recombination and enhance the available photoex-cited electrons,while the 3D carbon hollow spheres can act as electron traps to accelerate the charge separation and offer abundant active sites for solar water splitting reaction.

关键词： Cartbon hollow sphere Cu-doped TiO_(2) Photocatalytic H_(2)generation

LiMn_2O_4/CNTs and LiNi_(0.5)Mn_(1.5)O_4/CNTs Nanocomposites as High-Performance Cathode Materials for Lithium-Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English letters) 2015年第1期28卷 122-128页

作者： Thang Van le Ha Tran Nguyen Anh Tuan Luu Man Van Tran Phung Loan My le Faculty of Materials Technology Ho Chi Minh University of Technology 268 Ly Thuong Kiet Ward 14 District 10 Ho Chi Minh City Vietnam Department of Physical Chemistry University of Science VNUHCM 227 Nguyen Van Cu Street District 5 Ho Chi Minh CityVietnam

The demand of higher energy density and higher power capacity of lithium（Li）-ion secondary batteries has led to the search for electrode materials whose capacities and performance are better than those available today. Carbon nanotubes（CNTs）, with their unique properties such as 1D tubular structure, high electrical and thermal conductivities, and extremely large surface area, have been used as materials to prepare cathodes for Li-ion batteries. The structure and morphology of CNTs were analyzed by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, and transmission electron microscopy（TEM）. The functional groups on the purified CNT surface such as –COOH, –OH were characterized by Fourier Transform infrared spectroscopy. The electrode materials were fabricated from LiMn2O4（LMO）, doped spinel LiNi0.5Mn1.5O4, and purified CNTs via solid-state reaction. The structure and morphology of the electrode were characterized using XRD, SEM, and TEM. Finally, the efficiency of the electrode materials using CNTs was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy.

关键词： Nanocomposites Carbon nanotubes(CNTs) Spinel materials Lithium-ion batteries(LIBs)

Element Analysis of Ceramic Coatings under Spherical Indentation with Metallic Interlayer: PartⅡRing Crack

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2006年第5期22卷 594-598页

作者： Minh-Quy le Seock-Sam KIM Department of Mechanics of Materials & Structures Faculty of Mechanical Engineering Hanoi University of TechnologyDai Co Viet RoadHanoiVietnam School of Mechanical Engineering Kyungpook National University Daegu 701-702Korea

Spherical indentation of ceramic coatings with metallic interlayer was performed by means of axisymmetric finite element analysis （FEA）. Two typical ceramic coatings with relatively high and low elastic modulus deposited on aluminum alloy and carbon steel were considered. The fracture mechanics of the ceramic coatings mechanisms due to occurrence of surface ring cracks extending traverse the coating thickness under spherical indentation are investigated within the framework of linear fracture mechanics. The J-integral associated to such cracks was computed. The evolution of J-integral vs the crack length and the indentation depth was studied. The effects of the interlayer, the coating and the substrate on the J-integral evolution were discussed. The results show that a suitable metallic interlayer can improve the fracture resistance of the coating systems under the same indentation conditions through reducing the J-integral.

关键词： Finite element analysis Ceramic coatings Indentation Interlayer Crack

Electronic Band Structure of Carbon Nanotubes with Kekule Structure

在线全文

学校读者我要写书评

暂无评论

Chinese Physics letters 2013年第9期30卷 97-100页

作者： Nguyen Ngoc Hieu le Cong Nhan Center of Research and Development Duy Tan UniversityK7/25 Quang TrungDa NangViet Nam Department of Environmental Science Saigon University273 An Duong VuongHo Chi Minh cityViet Nam

Electronic band structure of carbon nanotubes with the Kekule structure is studied by the tight-binding *** give a complete geometrical approach to structural properties of carbon nanotubes with bond alternation,including chiral and achiral *** the Kekule is introduced,all carbon nanotubes become semiconducting with a small band gap at the Fermi *** band gap of the carbon nanotubes depends only on the difference between C–C bond lengths or the resonance integrals.

关键词： carbon structure Fermi

Science letters:Development of supported boron-doping TiO_2 catalysts by chemical vapor deposition

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 Zhejiang University-Science A(Applied Physics & Engineering) 2008年第1期9卷 109-112页

作者： Xing-wang ZHANG le-cheng leI nstitute of Environmental Pollution Controlling Technologies Zhejiang University Hangzhou 310028 China

In this study, supported nonmetal (boron) doping TiO2 coating photocatalysts were prepared by chemical vapor deposition (CVD) to enhance the activity under visible light irradiation and avoid the recovering of TiO2. Boron atoms were successfully doped into the lattice of TiO2 through CVD, as evidenced from XPS analysis. B-doped TiO2 coating catalysts showed drastic and strong absorption in the visible light range with a red shift in the band gap transition. This novel B-TiO2 coating photocatalyst showed higher photocatalytic activity in methyl orange degradation under visible light irradiation than that of the pure TiO2 photocatalyst.

关键词： Chemical vapor deposition (CVD) TiO2 Boron Visible light Photocatalysis

High Temperature Oxidation Behavior of High Speed Steel for Roll in Water Vapor

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5期25卷 134-138页

作者： ZHOULi LIUFang LIUChang-sheng SUNDa-le CollegeofMaterial＆Metallurgy NortheasternUniversityShenyang110004China BAOSHANIron＆SteelCO. LTD.TechnologyCenterShanghai201900China

The oxidation behavior of high speed steel (HSS) was researched by high temperature thermo balance at 500 to 800 °C in water vapor. The morphology was observed by scanning electron microscope, the microstructure of oxide scale was analyzed by energy dispersive spectrometer and X-ray diffraction spectrum. The results indicate that the mass gain of HSS increases with oxidation temperature rising, the effect of oxidation temperature on the morphology is obvious, water vapor temperature only affects mass gain and affects hardly morphology of oxide scale at the same oxidation temperature. The relevant oxidation mechanisms are also discussed.

关键词：高速钢高温氧化等温氧化集中放大硬质合金

QUENCHING AND AGEING BEHAVIORS OF Mg-Li-Zn ALLOY

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1997年第3期7卷 41-45页

作者： le, Qichi Gui, Jianzhong Liu, Hanwu Northeastern Univ Shenyang China

ＱＵＥＮＣＨＩＮＧＡＮＤＡＧＥＩＮＧＢＥＨＡＶＩＯＲＳＯＦＭｇＬｉＺｎＡＬＬＯＹ①ＬｅＱｉｃｈｉ，ＣｕｉＪｉａｎｚｈｏｎｇ，ＬｉｕＨａｎｗｕＤｅｐａｒｔｍｅｎｔｏｆＭｅｔａｌＦｏｒｍｉｎｇ，ＳｃｈｏｌｏｆＭａｔｅ... 详细信息

ＱＵＥＮＣＨＩＮＧＡＮＤＡＧＥＩＮＧＢＥＨＡＶＩＯＲＳＯＦＭｇＬｉＺｎＡＬＬＯＹ①ＬｅＱｉｃｈｉ，ＣｕｉＪｉａｎｚｈｏｎｇ，ＬｉｕＨａｎｗｕＤｅｐａｒｔｍｅｎｔｏｆＭｅｔａｌＦｏｒｍｉｎｇ，ＳｃｈｏｌｏｆＭａｔｅｒｉａｌａｎｄＭｅｔａｌｕｒｇｙ，...

关键词： Mg Li Zn quenching ageing