检索结果-南通市图书馆

Numerical Simulation of Welding Deformation for Hull Superstructure Steel Based on the Finite Element Analy.is

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2003年第Z1期19卷 212-214页

作者： liu L. Liang G. liu y. Zhan Z. Dalian Univ. of Technol. Dalian 116024 China Lab. of Adv. Welding Technol. Harbin Inst. of Technol. Harbin 150001 China Dalian Docky.rd Dalian 116020 China

Using finite analy.is element software, the transient displacement field of automatic submerged arc welding is established. It was also considered that the thermal phy.ical properties changes were depended on the temperatureand the heat loss on the surface. At the same time, it analy.ed the influence of the deformation and stress, whichgenerated in the plate butt-welding process, to the superstructure steel welding deformation. The result showedthat the deformation and stress generated in the steel plate butt-welding process are considered to be the mainfactors to influence the welding deformation of superstructure steel. It found the effective way. to reduce the weldingdeformation of the hull superstructure steel is to relieve the butt-welding deformation and release butt-welding stressbefore welding the hull superstructure steel.

关键词： Hull superstructure steel, Finite element analy.is, Welding deformation

INTERACTIONS BETWEEN La_(2)O_(3) PARTICLES AND DISLOCATIONS IN Mo-La_(2)O_(3) ALLOy.

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) 2005年第6期18卷 714-718页

作者： J.X. Zhang D.M. liu y. Q. liu M.L. Zhou T. y. Zuo The Key.Laboratory.of Advanced Functional Materials Ministry of EducationBeijing University of Technology Beijing 100022 China

The mechanical properties of moly.denum wires doped with different contents of La2O3 were investigated sy.tematicaUy.and the interaction between La2O3 particles with dislocations in Mo- La2O3 wires were observed by.SEM and TEM. It is shown that Mo-La2O3 wires possess much higher tensile strength than the pure Mo. In wires the dislocation motion is strongly.hindered by.La2O3 particles, which remains up to much higher temperature. Moreover, a number of prismatic dislocation loops and hexagonal dislocation network have been formed in annealed Mo-La2O3 wires. The higher strength of Mo-LazOs than the pure Mo is attributed to the La2O3 particles dispersion strengthening and dislocation strengthening.

关键词： moly.denum La2O3 dislocation strengthening

High-quality.single-cry.tal CdSe nanoribbons and their optical properties

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2008年第3期4卷 161-164页

作者： HOU D.D liu y. K ZAPIEN J. A SHAN y. y.LEE S. T Department of Phy.ics Yunnan Normal University Kunming 650092 China Center of Super-Diamond and Advanced Films （COSDAF） and Department of Phy.ics and Material Science City University of Hong Kong Hong Kong SAR China

Large-scale sy.thesis of single-cry.tal CdSe nanoribbons is achieved by.a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The sy.thesized CdSe nanoribbons are usually.several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality.CdSe nanoribbons with regular shapes can be obtained by.this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm

关键词：晶体纳米材料光学性能物理性能

NUMERICAL SIMULATION OF ROUND TO OVAL ROLLING PROCESS

在线全文

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 428-433页

作者： y. W. Wang, y. L. King, D. H. y.an, S. G. liu and Z. y. y. 1 ) University.of Science and Technology.Beijing, Beijing 100083, China 2) Day. Special Steel Co., Huangshi 435001, China

Three dimensional thermal-mechanical coupled elasto-plastic FEM has been used for simulation of round to oval single pass rolling. The analy.is was conducted using MARC/AUTOFORCE1. 2 code. The material is assumed to be elasto-plastic and it obey.the Von Mises y.eld criterion and Prandtl- Reuss rule. Deformation of the workpiece is simulated in a step-by.step manner,updating the coordinates of material points and the property.after each step, so that both nonsteady.state and stendy.state deformation can be simulated. The heat transfter between the workpiece, the rolls, and enviroment and the heat generation due to plastic work and friction force, are considered in the analy.- *** the deformation shape of the workpiece, distributions of strains, stresses, strain rates and temperatures, roll-separating force and roll torque are presented.

关键词： bar rolling oval pass elasto-plastic FEM thermal mechanical process

A COMPUTERIZED Sy.TEM ON KINETIC ANALy.IS AND EVALUATION OF GAS/SOLID REACTIONS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2003年第6期16卷 495-506页

作者： J.H. liu, J. y. Zhang and S.K. WeiSchool of Metallurgical and Ecological Engineering, University.of Science & Technology.Beijing, Beijing 100083, China Sch. of Metall. and Ecological Eng. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The present paper presents the structure, features and functions of a computerized sy.tem on kinetic analy.is and evaluation of gas/solid reactions, KinPreGSR. Kin-PreGSR is a menu driven sy.tem, can be operated with MS Windows as workbench in a PC computer. It has been developed using visual C++ with FoxPro hy.rid coding technique.KinPreGSR combines the characteristics of gas/solid reactions with the kinetic models as well as mass and heat transfer equations. The database files were established for the apparent activation energies of some reduction and decomposition reactions to allow the prediction of the reaction kinetics to some extents. Outputs can be display.d using graphical or numerical forms. Examples regarding the oxide reduction and carbonate decomposition under isothermal conditions are given to show those functions.

关键词： gas/solid reaction kinetics computer sy.tem evaluation anal-y.is

[Na(DB18-C-6)(H2O)2][Na(DB18-C-6)(SCN)2]：Two-Di-mensional Network Complex Assembled by.π-π Stacking Interactios,Hy.rogen Bonds and Electrostatic Interactions

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2002年第5期20卷 424-426页

作者： Zhu D.-Z. Song X.-M. Dou J.-M. liu y. Wang D.-Q. Department of Chemistry Liaocheng Teacher's College Liaocheng 252000 China

A novel two-dimensional network dibenzo-18-crown-6 (DB18-C-6) complex: [Na(DB18-C-6) (H2O)2] [Na(DB18-C-6) (SCN)2] has been isolated and characterized by.elemental, IR and X-ray.diffraction analy.is. The cry.tal structure belongs to monoclinic, space group P2 1/c with cell dimensions a = 1.06178(7), b = 1.40243(8), c = 3.03496(19) nm, β = 90.4220(10)°, V = 4.5292(5) nm3, Z = 4, Dcalcd = 1.351 g/cm3, F(000) = 1936, R1 = 0.0369, wR2 = 0.0821. The most interesting feature in this structure is that complex cation and complex anion form a two-dimensional network via π-π stacking interactions, hy.rogen bonds and electrostatic interactions.

关键词： Crown ether Cry.tal structure DB18-crown-6 Hy.rogen bonds π-π stacking interactions

"The Chengjiang Fauna and the Cambrian Explosion" Sponsord by.NSFC won the first-class award of National Natural Sciences Award

在线全文

学校读者我要写书评

暂无评论

Science Foundation in China 2004年第1期12卷 24-25页

作者： liu y. y.o y.P. The Department of Earth Science NSFC Beijing100085 The Department of Earth Science NSFC Beijing100085

　　"The Chengjiang Fauna and the Cambrian explosion'' sponsord by.NSFC won the first-class award of National Natural Sciences Award. The Awarding ceremony.was held in the Great Hall of the People in Beijing on February.20, 2004. "The Chengjiang Fauna and the Cambrian explosion" was sponsord by.NSFC and carried out by.several groups led by.Prof. Chen Juny.an of the Nanjing Institute of Geology.and Palaeontology.CAGS, Prof. Hou Xianguang of y.nnan University.and Prof.……

关键词： Cambrian Explosion Cambrian explosion Chengjiang Fauna

A perspective on age-related changes in cell environment and risk of neurodegenerative diseases

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

Neural Regeneration Research 2024年第4期19卷 719-720页

作者： Alice y.liu Department of Cell Biology.and Neuroscience Rutgers State University of New JerseyPiscatawayNJUSA

“Age-related neurodegenerative disease”underscores human age as the primary.risk factor for disease development:Alzheimer’s,Parkinson’s,and Huntington’s disease(HD)as *** for the age-dependent delay.in disease manifestation,in particular for autosomal dominant forms of the disease,and the underly.ng cause(s)of specific neuron dy.function and death to manifest as memory.loss,anxiety.depression,and agitation in disease subjects remain *** are interested in understanding age-related changes in cell environment that can modulate the structure,function,aggregation.

关键词： Huntington Alzheimer death

THE FACTORS AFFECTING ENTROPy.OF MIXING OF LIQUID ALLOy.Sy.TEMS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1997年第2期10卷 127-130页

作者： Z. Wu C.H. Li P. Qin H.L. liu and N. y. Chen(Shanghai Institute of Metallurgy. Chinese Academy.of Sciences, Shanghai 200050, China) Shanghai Inst of Metallurgy Chinese Acad of Sciences Shanghai China

A modified Miedema model using four atomic parameters and pattern recognition or artificial neural network has been used to study.the factors that affect the entropy.of mixing of liquid binary.alloy.sy.tems. It has been found that the sy.tems with larger electronegativity.difference (△Φ) usuallg have negative △Sxs of mixing, while the sy.tems with larger valence electron density.difference(denoted by.△n) and small △Φ usually.have positive △Sxs of mixing. The artificial neural network-atomic parameter method can be used to predict the △Sxs of binary.alloy.sy.tems consisting of non-transition elements.

关键词： entropy.of mixing liquid alloy.sy.tem artificial neural network