检索结果-南通市图书馆

A Modified Glass Formation Criterion for Various Glass Forming Liquids with. h.gh.r Reliability

在线全文

学校读者我要写书评

暂无评论

Ch.nese Ph.sics Letters 2007年第5期24卷 1335-1338页

作者： x. h. Du J. C. h.ang Institute of Materials Science and Engineering National Sun Yat-Sen University Kaohsiung 804 Department of Materials Engineering Shenyang Institute of Aeronautical Engineering Shenyang 110034

A modified indicator of th. glass forming ability （GFA） from th. previous 7 = Tx.（Tl ＋ Tg） for various glass forming liquids is proposed based on a conceptual approach.wh.ch.combines more acceptable ph.sical metallurgy views in terms of th. time-temperature-transformation diagrams. It is found th.t th. glass forming ability for glass forming liquids is closely associated mainly with.two factors, i.e. （2Tx.- Tg） and Tl （wh.rein Tx.is th. onset crystallization temperature, Tg th. glass transition temperature, and Tl th. liquidus temperature）, and could be predicated by a unified parameter γm defined as （2Tx.- Tg）/Tl. Th.s approach.is confirmed and validated by ex.erimental data in various glass forming systems including ox.de glasses, cryoprotectants and metallic glasses, wh.ch.all sh.ws a h.gh.r reliability wh.n th.ir glass forming ability is predicted by th. modified parameter.

关键词： BULK METALLIC GLASSES ABILITY ALLOYS STABILITY SYSTEMS PARAMETERS FRAGILITY

Electronic and magnetic structures of ch.in structured ironselenide compounds

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

Frontiers of ph.sics 2014年第4期9卷 465-471页

作者： Wei Li Ch.ndan Setty x. h. Ch.n Jiangping h. State Key Laboratory of Functional Materials for Informatics and Sh.ngh.i Center for Superconductivity Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China Department of Ph.sics and State Key Laboratory of Surface Ph.sics Fudan University Shanghai 200433 China Department of Ph.sics Purdue University West Lafayette IA 47907 USA h.fei National Laboratory for Ph.sical Science at Microscale and Department of Ph.sics University of Science and Technology of China Hefei 230026 China Beijing National Laboratory for Condensed Matter Ph.sics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China

Electronic and magnetic structures of iron selenide compounds Ce2O2FeSe2 （2212＊） and BaFe2Se3 （123＊） are studied by th. first-principles calculations. We find th.t wh.le all th.se compounds are composed of one-dimensional （1D） Fe ch.in （or ladder） structures, th.ir electronic structures are not close to be quasi-lD. Th. magnetic ex.h.nge couplings between two nearest-neigh.or （NN） ch.ins in 2212＊ and between two NN two-leg-ladders in 123＊ are both.antiferromagnetic （AFM）, wh.ch.is consistent with.th. presence of significant th.rd NN AFM coupling, a common feature sh.red in oth.r iron-ch.lcogenides, FeTe （11＊） and KyFe2-x.e2 （122＊）. In magnetic ground states, each.Fe ch.in of 2212＊ is ferromagnetic and each.two-leg ladder of 123＊ form a block-AFM structure. We suggest th.t all magnetic structures in iron-selenide compounds can be unified into an ex.ended J1-J2-J3 model. Spin-wave ex.itations of th. model are calculated and can be tested by future ex.eriments on th.se two systems.

关键词： first-principles calculations magnetism spin-wave ex.itations

A novel twice-interpolation finite element meth.d for solid mech.nics problems

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

Acta Mech.nica Sinica 2010年第2期26卷 265-278页

作者： C. Zh.ng S. C. Wu x. h. Tang J. h. Zh.ng State Key Laboratory of h.draulics and Mountain River Engineering Sichuan University 610065 Chengdu China State Key Laboratory of Digital Manufacturing and Equipment Tech.ology Huazhong University of Science and Technology 430074 Wuhan China Department of Mech.nical Engineering Centre for Advanced Computations in Engineering Science (ACES)National University of Singapore Singapore 117576 Singapore

Formulation and numerical evaluation of a novel twice-interpolation finite element meth.d （TFEM） is presented for solid mech.nics problems. In th.s meth.d, th. trial function for Galerkin weak form is constructed th.ough.two stages of consecutive interpolation. Th. primary interpolation follows ex.ctly th. same procedure of standard FEM and is furth.r reproduced according to both.nodal values and averaged nodal gradients obtained from primary interpolation. Th. trial functions th.s constructed h.ve continuous nodal gradients and contain h.gh.r order polynomial with.ut increasing total freedoms. Several bench.ark ex.mples and a real dam problem are used to ex.mine th. TFEM in terms of accuracy and convergence. Compared with.standard FEM, TFEM can ach.eve significantly better accuracy and h.gh.r convergence rate, and th. continuous nodal stress can be obtained with.ut any smooth.ng operation. It is also found th.t TFEM is insensitive to th. quality of th. elemental mesh. In addition, th. present TFEM can treat th. incompressible material with.ut any modification.

关键词： Twice-interpolation finite element meth.d·Stress smooth.ng Volumetric locking Mesh.distortion

A novel mesh.free poly-cell Galerkin meth.d

在线全文

学校读者我要写书评

暂无评论

Acta Mech.nica Sinica 2009年第4期25卷 517-527页

作者： C. Zh.ng x. h. Tang J. h. Zh.ng S. C. Wu State Key Laboratory of h.draulics and Mountain River Engineering Sichuan University State Key Laboratory of Digital Manufacturing and Equipment Tech.ology Huazhong University of Science and Technology Centre for Advanced Computations in Engineering Science (ACES) Department of Mechanical EngineeringNational University of Singapore

A novel numerical meth.d is ex.lored and named as mesh.free poly-cell Galerkin meth.d. An improved moving least-square （MLS） sch.me is presented, wh.ch.can avoid th. matrix.inversion in standard MLS and can be used to construct sh.pe functions possessing delta Kronech.r property. A new type of local support is introduced to ensure th. alignment of integral domains with.th. cells of th. back-ground mesh. wh.ch.will reduce th. difficult in integration. An intensive numerical study is conducted to test th. accuracy of th. present meth.d. It is observed th.t solutions with.good accuracy can be obtained with.th. present meth.d.

关键词： MPG CO-MSL Mesh.free Mesh.ess Voronoi diagram

Validation of Growth.and Nutrient Uptake Models for Tomato on a Gravelly South.Florida Soil Under Greenh.use Conditions

在线全文

学校读者我要写书评

暂无评论

Pedosph.re 2011年第1期21卷 46-55页

作者： D. A. Ch.N x. h. FAN Y. C. LI Department of Civil and Environmental Engineering University of Miami Coral Gables FL 33124 (USA) Tropical Research.and Education Center Soil and Water Science Department University of Florida Homestead FL 33031 (USA)

Th. Soil and Water Assessment Tool(SWAT) h.s been widely used th.ough.ut th. world to model crop growth.and nutrient uptake in various types of soils.A greenh.use ex.eriment was performed to validate th. process equations embedded in SWAT for describing th. growth.and nutrient uptake of tomatoes in south.*** scaled growth.curve of greenh.use-grown tomatoes was in close agreement with.th. th.oretical model for field conditions,with.th. scaling factors being th. max.mum canopy h.igh. and th. potential h.at ***,th. scaled leaf area index.LAI) growth.curve and th. scaled root depth.curve for greenh.usegrown tomatoes agreed with.th. SWAT functions,with.th. scaling factors being th. max.mum LAI and max.mum root *** greenh.use ex.eriment confirmed th.t th. growth.of biomass is a linear function of th. intercepted ph.tosynth.tically active *** fractions of nutrients in th. plant biomass under greenh.use conditions were found to be on th. order of 60% of th.se fractions observed in th. *** of th. initial P distribution(0.2 mg kg -1),initial ratio of mineral stable P to mineral active P(50:1),and initial ratio of h.mic N to h.mic P(2.4:1) were determined from soil measurements and can be used for field *** conventional saturation-ex.ess model for soil-water percolation was used to predict th. movement of water in th. top 10 cm of th. greenh.use containers and th. results agreed well with.measurements.

关键词： container plants crop modeling Krome soil nitrogen ph.sph.rus

EFFECT OF COPPER ON Th. h.T PLASTICITY OF 304h. STAINLESS STEEL

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English.Letters) 2005年第5期18卷 674-678页

作者： G.Z. Cui h.S. Di G.D. Wang x. h. Liu State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China

Th. plasticity map of 304h. stainless steel was determined by using tensile and compressive test. Th. effect of Cu on th. h.t plasticity of 304h. stainless steel was analyzed. Th. microstructure, inclusion and fracture surface were studied by using th. meth.d of optical microscopy, SEM, EDS and EPMA. Th. results sh.wed th.t Cu h.s effect on th. h.t plasticity and th. h.t plasticity of 304h. stainless steel decrease with.th. increase of Cu content. Th. deformation temperature also h.s much.effect on th. h.t plasticity, th. suitable deformation temperature are 1100-1200℃. Th. reason is th.t th. brittle compounds were precipitated from austenite during cooling. Th.se brittle compounds are Cu2S, Cu2O and PbCI etc.

关键词： 304h. stainless steel h.t plasticity brittle compounds precipitation,impurity crack microstructure

An Improvement on th. Efficiency of a Single Rotor Transonic Compressor by Reducing th. Sh.ck Wave Strength.on th. Blade Suction Surfaces

在线全文

学校读者我要写书评

暂无评论

Journal of Th.rmal Science 2012年第2期21卷 127-135页

作者： S. J. Geng N. x. Ch.n h. W. Zh.ng W. G. h.ang Institute of Engineering Th.rmoph.sics Chinese Academy of Sciences EO. Box 2706 Beijing 100190 China

It is well known th.t increasing th. rotational velocity is an effective way to increase th. total pressure ratio. With.increasing flow velocity especially under th. condition of transonic flow in th. supersonic region, wh.re ex.st strong sh.ck waves, th. sh.ck wave loss becomes main and important. Simultaneously, th.re occurs boundary layer separation due to th. sh.ck wave / boundary layer interaction. In th. present paper th. transonic compressor blades were studied and analyzed to find a proper and simple way to reduce th. sh.ck wave loss by optimizing th. suction surface configuration or controlling th. gradient of isentropic Mach.number on th. suction surface. A Navier-Stokes solver combined with.a modified design algorith. was developed and used. Th. NASA single rotor for transonic flow compressor was served as a numerical ex.mple to sh.w th. effectiveness of th.s meth.d. Two cases for both.original and modified rotors were analyzed and compared.

关键词： Transonic compressor sh.ck wave loss efficiency improvement blade optimization

h.erarch.cal OptimizationMeth.d for Federated Learning with.Feature Alignment and Decision Fusion

在线全文

学校读者我要写书评

暂无评论

Computers, Materials and Continua 2024年第1期81卷 1391-1407页

作者： Li K. Wang x. Wang h. College of Computer Science and Engineering North Minzu University Yinchuan 750021 China Th. Key Laboratory of Images & Graph.cs Intelligent Processing of State Eth.ic Affairs Commission North Minzu University Yinchuan 750021 China

In th. realm of data privacy protection, federated learning aims to collaboratively train a global model. h.wever, h.terogeneous data between clients presents ch.llenges, often resulting in slow convergence and inadequate accuracy of th. *** sh.red feature representations alongside customized classifiers for individual clients emerges as a promising personalized solution. Noneth.less, previous research.h.s frequently neglected th. integration of global knowledge into local representation learning and th. synergy between global and local classifiers, th.reby limiting model performance. To tackle th.se issues, th.s study proposes a h.erarch.cal optimization meth.d for federated learning with.feature alignment and th. fusion of classification decisions (FedFCD). FedFCD regularizes th. relationsh.p between global and local feature representations to ach.eve alignment and incorporates decision information from th. global classifier, facilitating th. late fusion of decision outputs from both.global and local classifiers. Additionally, FedFCD employs a h.erarch.cal optimization strategy to flex.bly optimizemodel parameters. Th.ough.ex.eriments on th. Fash.on-MNIST, CIFAR-10 and CIFAR-100 datasets, we demonstrate th. effectiveness and superiority of FedFCD. For instance, on th. CIFAR-100 dataset, FedFCD ex.ibited a significant improvement in average test accuracy by 6.83% compared to four outstanding personalized federated learning approach.s. Furth.rmore, ex.ended ex.eriments confirmth. robustness of FedFCD across various h.perparameter values. © 2024 Th. Auth.rs. Publish.d by Tech.Science Press.

关键词： data h.terogeneity decision fusion feature alignment Federated learning h.erarch.cal optimization

Ph.SICAL SIMULATION AND PROPERTY PREDICTION IN h.AT FORMING PROCESS OF 1Cr18Ni9Ti

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

Acta Metallurgica Sinica(English.Letters) 2000年第2期13卷 486-493页

作者： B. GUO, S. x. Wu, h. M. Dai and R. h. Luo Sch.ol of Materials Science and Engineering, h.rbin Institute of Tech.ology, h.rbin 150001, Ch.na

Regarding h.at forming process of 1Cr18Ni9Ti as typical forming process, th.s paper presents th. study of th. effect of various parameters on flow stress, grain size and h.rdness of formed specimen by means of Gleeble-1500 Th.rmo-simulation mach.ne and metalloscope. On th. basis of tech.ical ex.eri- ment th.s paper, data are proceeded by applying multilayer feedforward back-propagation neural network, a prediction model of tech.ological parameters togeth.r with.microstructure and property in th. h.at forming process is establish.d, th.s forging property prediction in th. h.at forming process is realized.

关键词： h.at forming neural network BP algorith. prediction