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FOURIER-LEGENDRE SPECTRAL METHOD FOR THE UNSTEADY NAVIER-STOKES EQUATIONS

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journal of Computational Mathematics 1995年第2期13卷 144-155页

作者： li, j GUO, BY ACAD SINICA CTR COMPBEIJING 100080PEOPLES R CHINA SHANGHAI UNIV SCI & TECHNOL SHANGHAI 201800PEOPLES R CHINA

Fourier-Legendre spectral approximation for the unsteady Navier-Stokes equations is analyzed. The generalized stability and convergence are proved respectively.

关键词： Math FOURIER-LEGENDRE SPECTRAL METHOD FOR THE UNSTEADY NAVIER-STOKES EQUATIONS

Effect of arc sprayed coatings on tensile properties of a type 316 steel

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中国有色金属学会会刊：英文版 2004年第z1期14卷 95-99页

作者： liU Gui-min MA li-li K.j.Kurzydlowski Faculty of Materials Science and Engineering Academy of Armored Force EngineeringBeijing 100072 China Faculty of Materials Science and Engineering Academy of Armored Force EngineeringBeijing 100072 China Faculty of Materials Science and Engineering Warsaw University of Technology Warsaw Poland

The effect of Al- and AlSiRE-coatings obtained by arc spray (AS) and high velocity arc spray (HVAS) technologies, on the tensile properties of type 316 steel specimens strained at elevated temperatures in air and vacuum has been systematically investigated. It is found that both temperature and environment play an important role in determining the mechanical properties of the coated 316 steel specimens strained at elevated temperatures. And the quantitative changes of surface roughness of coatings before and after straining correspond to the mechanical properties of the 316 steel substrate.

关键词： type 316 steel arc spray high velocity arc spray coating tensile property

Ab initio band structure calculations on polymers (C5H3X)n (X=CH,N,P,As)

维普期刊数据库评论

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维普期刊数据库

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Chinese journal of Chemistry 1997年第4期15卷 289-295页

作者： lin, CS li, j liu, CW CHINESE ACAD SCI FUJIAN INST RES STRUCT MATTERSTATE KEY LAB STRUCT CHEMFUZHOU 350002FUJIANPEOPLES R CHINA

The ab initio crystal orbital calculations on conjugated aromatic six-membered rings polymers, namely, poly(p-phenylene) (PPP), poly(2,5-pyridinediyl) (PPD), poly(2,5-phosphabenzene) (PPB) and ploy(2,5-arsabenzene) (PAB) are reported. The comparison of the important electronic properties of these polymers, such as band gap, bandwidth, ionization potential and electron affinity, indicates that PPP is the best intrinsic semiconductor, and PPD has the best prospects for forming n-doped conducting materials.

关键词： band structure poly(p-phenylene) ab initio crystal orbital

INFLUENCE OF HEAT TREATMENT ON OXIDATION PROPERTIES OF C/C COMPOSITES FABRICATED BY HIGH PRESSURE IMPREGNATION CARBONIZATION

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 426-430页

作者： Q.Chen H.j.li A.j.li H.M.Han K.Z.li School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 China

Felt base carbon/carbon composites fabricated by super-high pressure impregnation carbonization process (SPIC) were heat treated at high temperature 2773K. The oxidation properties of felt base carbon/carbon composites were investigated at different temperatures (773-1173K), and the microstructures of carbon/carbon composites were studied by SEM and X-ray diffraction. The experimental results showed that the inter-laminar distance of (002) plane (d002) deceased while the microcrystalline stack height (Lc) increased. The oxidation rate of felt base carbon/carbon composites was invari-able at certain temperatures. The oxidation mechanism of carbon/carbon composites changed remarkably at the oxidation temperature 973K. At the initial oxidation stage of carbon/carbon composites, carbon matrix was oxidized much more rapidly than carbon felt.

关键词： carbon/carbon composites high pressure impregnation carbonization high temperature heat treatment oxidation mi-crostructure

Synthesis and Catalyzing Behavior of Olefin Polymerization of cis-Cyclopentene Bridged Titanocenes

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Chinese Chemical Letters 2000年第11期11卷 979-980页

作者： li, jS Xiong, CH Ma, YQ li, j Chen, X Nankai Univ Inst Elementoorgan Chem Tianjin 300071 Peoples R China Tianjin Normal Univ Dept Chem Tianjin 300070 Peoples R China

Two cis-cyclopentene bridged titanocenes have been synthesized. Two homogeneous Ziegler catalysts prepared by activation of synthesized compounds with methylalumoxane are active for ethylene polymerization reactions.

关键词： cis Ti Synthesis and Catalyzing Behavior of Olefin Polymerization of cis-Cyclopentene Bridged Titanocenes

Research on the Influence of Steam Curing on Properties of C50 Shield Segment Concrete

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武汉理工大学学报 2010年第17期32卷 137-140页

作者： li j H Wuhan Harbour Engineering Design & Research Co. Ltd.Wuhan 430071China Key Lab of Large-span Bridge Construction Technology Ministry of CommunicationsWuhan 430071China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

The effects of steam curing on mechanical properties,drying shrinkage,cracking sensitivity,anti-permeability,and carbonation resistance of C50 shield segment concrete were investigated,which were compared with the standard curing conditions. The results indicated that steam curing could increase early strength of concrete and reduce its drying shrinkage. However,steam curing reduced later strength of concrete,increased its crack sensitivity and deteriorated its anti-permeability and carbonation resistance. Moreover,the incorporation of fly ash could improve the durability of steam-cured concrete.

关键词： shield segment concrete steam curing properties influence

High-magnetic-field induced charge order in high-T_c cuprate superconductors

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Chinese Physics B 2019年第11期28卷 25-42页

作者： L X Zheng j li T WU Hefei National Laboratory for Physical Science at Microscale University of Science and Technology of ChinaHefei 230026China Key Laboratory of Strongly-coupled Quantum Matter Physics University of Science and Technology of ChinaChinese Academy of SciencesHefei 230026China CAS Center for Excellence in Superconducting Electronics(CENSE) Shanghai 200050China CAS Center for Excellence in Quantum Information and Quantum Physics Hefei 230026China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

In the last few years, charge order and its entanglement with superconductivity are under hot debate in high-Tc community due to the new progress on charge order in high-Tc cuprate superconductors YBa2Cu3O6+x. Here, we will briefly introduce the experimental status of this field and mainly focus on the experimental progress of high-field nuclear magnetic resonance(NMR) study on charge order in YBa2Cu3O6+x. The pioneering high-field NMR work in YBa2Cu3O6+x sets a new stage for studying charge order which has become a ubiquitous phenomenon in high-Tc cuprate superconductors.

关键词： charge order cuprates nuclear magnetic resonance YBa2Cu3O6+x superconductors competing order

Magnetic Properties of Ni Nanoparticles and Ni(C) Nanocapsules

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journal of Materials Science & Technology 2002年第2期18卷 99-100页

作者： Z.j.li G.H.Wen 等 ShenyangNationalLaboratoryforMaterialsScienceandInternationalCentreforMaterialsPhysics InstituteofMetalResearchChineseAcademyofSciencesShenyang110016China DepartmentofPhysics H

Structure and magnetic properties of Ni nanoparticles and Ni(C) nanocapsules were studied. The carbon atoms hardly affect the lattice of Ni to form Ni-C solid solution or nickel carbides. The large thermal irreversibility in zero-field-cooled and zero-field magnetization curves indicates magnetic blocking with a wide energy barrier. Saturation magnetization, remanent magnetization and coercivity of Ni(C) nanocapsules decrease with increasing temperature.

关键词： Nanoparticles Nanocapsules Magnetic properties

A joint optimization framework for wheat harvesting and transportation considering fragmental farmlands

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Information Processing in Agriculture 2021年第1期8卷 1-14页

作者： P.He j.li Faculty of Engineering Nanjing Agricultural UniversityNanjing 210031PR China

Crop harvesting and transportation should be considered as an integrated system to be optimized aiming to reduce the total operational ***,current studies mainly focused on how to reduce operational cost for a link,not from integrated *** this paper,a joint problem which consists of harvesting and transportation problem is implemented and optimized to meet the better schedule with less operational *** harvesting and transportation problems could respectively be considered as a vehicle routing problem with multiple trips and a transportation problem,.These two problems should be optimized jointly because combine-harvesters and transporters should be synchronized at fragmental farmlands.A mixed integer programming is employed considering all constraints arising in the joint optimized ***,a hybrid algorithm is presented to find an optimum solution for this *** different cases are used to verify the performance of the hybrid ***,our real cases are used to prove that there is a significant improvement if the integrated wheat harvesting and transportation policy is *** results indicate that the model and algorithm is an effective approach to help farmers to decrease reaping costs.

关键词： Wheat Harvesting and transportation Vehicle routing Mixed integer programming