检索结果-南通市图书馆

science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 856-863页

作者： CAI Xin1,2.LIU JinSong1 & WANG ShengLie1 1 wuhan National Laboratory for Optoelectronics,school of Optoelectronic {2. and Engineering,Huazhong university of {2. and technology,wuhan 430074,china 2.school of {2.,wuhan university of technology,wuhan 43.070,china wuhan National Laboratory for Optoelectronics School of Optoelectronic Science and Engineering Huazhong University of Science and Technology Wuhan China school of science Wuhan University of Technology Wuhan China

The transverse effects of two Gauss waves mixing in a photovoltaic photorefractive crystal,i.e.,the dynamical evolutions of signal beam with different parameters,are traced numerically and *** the one-dimensional numerical simulations and two-dimensional experimental investigations show that the self-focusing effect of signal beam becomes more obvious as the intensity of pump beam and the angle between the signal and pump beams *** accordance with these results,the state of two Gaussian waves mixing is controllable.

关键词： numerical simulation experimental investigation two-wave mixing transverse effects Gaussian distribution

Sol-gel Preparation Copper-cadmium Halide DopedPhotochromic Glass Coating on Plate Glass

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 34-37页

作者： ShiyongLuo Jiayun Zhang Jixiang Liu Metallurgy school, university of {2. and technology Beijing, Beijing 100083, china wuhan university of technology, wuhan 43.070, china Metallurgy school University of Science and Technology Beijing Beijing 100083 China wuhan university of {2. Wuhan 430070 China

Copper-cadmium halide doped photochromic glass coating on plate glass has been prepared by a sol-gel process. The sample shows reversible photochromic effect. The results of X-ray diffraction (XRD) and infrared (IR) spectrum investigations indicate that the photochromic phase of tile coating is CuBr_xCl_(1-x), solid solution, and that the structure network of the coating is connected with the bonds of Si-O-Si, Si-O-B and Si-O-Al.

关键词： photochromic glass coating sol-gel photochromic phase, structure network

The characteristics of arc beam shaping in hybrid plasma and laser deposition manufacturing

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2006年第2期49卷 238-247页

作者： ZHANG Hai’ou1, QIAN Yingping1,3, WANG Guilan1 & ZHENG Qiguang2.1. school of Material science and {2., Huazhong university of science and {2., wuhan 430074, china 2. Institute of Laser {2. and Engineering, Huazhong university of science and {2., wuhan 430074, china 3. Mechanical Engineering College, Hubei university of {2., wuhan 430068, china school of Material science and {2. Huazhong University of Science and Technology Wuhan China Mechanical Engineering College Hubei University of Technology Wuhan China Institute of Laser technology and Engineering Huazhong University of Science and Technology Wuhan China

As a new direct metal prototyping technology,the hybrid plasma and laser deposition manufacturing (PLDM) is proposed in this paper. In order to figure out the characteristics of plasma arc beam and mould in the PLDM process of high temperature alloy, the high speed CCD camera is used to obtain the picture around the plasma arc. Afterwards the sketch of picture is clearly obtained. And the effect of laser parameter, such as average power, pulse width, pulse repetition frequency and the angle between laser beam and plasma arc beam on the plasma arc appearance, is studied experimentally. The results show that the modality of plasma arc beam is markedly influenced by laser beam. And the improvements of shape precision and surface state of the layer deposited by PLDM are confirmed.

关键词： plasma hybrid laser, direct deposition, plasma arc beam, molding character, high-temperature alloy.

Ferroelectric properties of Bi_(3.4)Ho_(0.6)Ti_3O_(12. thin films prepared by sol-gel method

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2008年第9期51卷 1439-1444页

作者： FU ChengJu1, HUANG ZhiXiong1, LI Jie2.& GUO DongYun3 1 school of Materials science and {2., wuhan university of {2., wuhan 43.070, china 2.school of Mechanical Engineering, Chongqing university of science and {2., Chongqing 400050, china 3 Department of Physics, wuhan university, wuhan 430072. china school of Materials science and {2. Wuhan University of Technology Wuhan China school of Mechanical Engineering Chongqing University of Science and Technology Chongqing China Department of Physics Wuhan University Wuhan China

We have prepared the Ho-substituted bismuth titanate (Bi3.4Ho0.6Ti3O12. BHT) thin films on Pt/Ti/SiO2.Si substrates using sol-gel method. The crystal structure and morphology of the films were characterized using X-ray diffraction and atomic force microscopy. The BHT film shows a single phase of Bi-layered Aurivillius structure and dense microstructure. The 2.r and 2.c of the 600-nm-thick BHT film were 38.4 μC/cm2.and 376.1 kV/cm, respectively at applied electric field 500 kV/cm. The dielectric constant and dielectric loss are about 310 and 0.015 at a frequency of 1 MHz, respectively. The Pr value decreased to 93% of its pre-fatigue values after 4.46×109 switching cycles at 1 MHz frenquency, and the BHT film shows good in-sulating behavior according to the test of leakage current.

关键词： Bi3.4Ho0.6Ti3O12 thin film sol-gel method ferroelectric property fatigue dielectric constant

Blank design optimization for stepped-section profile ring rolling

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2010年第6期53卷 1612-1619页

作者： QIAN DongSheng & HUA Lin school of Materials science and Engineering,{2. university of technology,{2. 43.070,china school of Materials science and Engineering Wuhan University of Technology Wuhan China

A stepped-section ring consists of two rectangular section rings,a big ring and a small ring,joined *** kind of ring is difficult to process by the ring rolling technique because of its complex cross-sectional *** a reasonable blank design is *** this paper,four blank designs,one is a rectangular cross-section and the other three are stepped-sections with different step volumes,are proposed and compared with each other using theoretical analysis,FE simulation and *** is shown that three of the designs can lead to volume flow from small ring into big ring during rolling,which is disadvantageous for shape formation and dimensional precision;however,the other design may result in good ring shape and high dimensional ***,the optimal blank design is determined to be the one in which the volumes of the big and small rings of the initial blank are equal to those of the final rings,respectively.

关键词： ring rolling stepped-section ring optimization design FE simulation

HCWCI/Carbon Steel Bimetal Liner by Liquid-Liquid Compound Lost Foam Casting

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2012年第10期19卷 13-19页

作者： XIAO Xiao-feng1,2. YE Sheng-ping2. YIN Wei-xin3, XUE Qiong4 (1. school of Mechanical Engineering and automation, {2. Textile university, {2. 430073, Hubei, china 2. State Key Laboratory of Material Processing and Die and Mould technology, Huazhong university of science and technology, {2. 430074, Hubei, china 3. {2. Zhike Abrasive-Resistant Material science and technology Development Co Ltd, {2. 430073, Hubei, china 4. College of science, {2. university of technology, {2. 430079, Hubei, china) school of Mechanical Engineering and automation Wuhan Textile University Wuhan Hubei China State Key Laboratory of Material Processing and Die and Mould technology Huazhong University of Science and Technology Wuhan Hubei China wuhan Zhike Abrasive-Resistant Material science and {2. Development Co Ltd Wuhan Hubei China College of science Wuhan University of Technology Wuhan Hubei China

Impact, friction and corrosion from the grinding balls and the grinding medium during the mineral processing result in liner breakage. Liner, made from Hadfield steel or alloyed steel, could not have served in wet grinding environment for more than ten months. Composite liner, made from HCWCI (high Cr white cast iron) and carbon steel, has been developed successfully with liquid-liquid composing process based on LFC (lost foam casting). The microstructure of composite was analyzed with optical microscope, SEM (scanning electron microscope)/EDX energy-dispersive X-ray and XRD (X-ray diffraction). According to micrograph, the combination region of two metals was staggered like dogtooth, no mixtures occurred between two liquid metals, and its interface presented excellent metallurgical bonding state. The results of mechanical property test show that, the hardness of HRC, the fracture toughness, and the bending strength are more than 61, 16.5 J/cm2.and 1 600 MPa, respectively. Comparison between liners made from bimetal composite and alloyed steel has also been investigated in industrial hematite ball mill. The results of eight months test in wet grinding environment prove that the service life of bimetal composite liner is three times as long as that of one made from alloyed steel.

关键词： composite liner bimetal liquid-liquid compound composite interface lost foam casting high Cr white cast iron

The Role of Calcium in Microstructural Refinement of AZ91 Magnesium Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan university of {2.(Materials science) 2006年第4期21卷 45-47页

作者：刘生发 school of Materials science and Engineering Wuhan University of Technology Wuhan 430070China

The effect of calcium addition on the microstructures of AZ91 magnesium alloy was investigated. It was found that a small amount of calcium in AZ91 allay produced a large decrease in the α- Mg grain size and the dispersed fine β-Mgt7 Alt2.phases. In addition, some Al4Ca particles were found to exist in the AZ91 alloy containing 0.5wt% Ca. EDS analysis and water-quenched technique revealed that the grain-refining mechanism of calcium for the AZ91 alloys was mainly attributed to the role of restricting growth of calcium in the primary α-Mg crystals.

关键词： AZ91 magnesium alloy calcium microstructural refinement

Binding Materials of Dehydrated Phases of Waste Hardened Cement Paste and Pozzolanic Admixture

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan university of {2.(Materials science) 2009年第1期24卷 140-144页

作者：吕林女 school of science Wuhan University of Technology

Fly ash （FA） and ground granulated blast-furnace slag （GGBFS） were added to improve the performances of regenerated binding materials （RBM） which refer to dehydrated phases with rebinding ability of waste hardened cement paste. Flowability tests, compressive strength tests, SEM, TG-DSC, and non-evaporable water content tests were employed to study the performances of the combined binding materials and the interactions between RBM, FA, and GGBFS. Results show that adding FA or GGBFS can improve the workability of RBM paste, and GGBFS has positive effects on strength of RBM. Pozzolanic reactions happen between RBM, FA, and GGBFS. And the activation effect of RBM to FA and GGBFS is superior to that of P.O grade-32.5 cement, especially at earlier ages, because of the high reactive f-CaO existing in RBM. On the advantages of the synergetic effects of RBM and pozzolanic admixtures such as FA and GGBFS, new combined binding materials can be prepared by blending them together.

关键词： combined binding materials dehydrated phase fly ash granulatedblast-furnace slag

On the new results of global attractive set and positive invariant set of the Lorenz chaotic system and the applications to chaos control and synchronization

在线全文

学校读者我要写书评

暂无评论

science in china(Series F) 2005年第3期48卷 304-321页

作者： LIAO Xiaoxin 1, 2. 3 , FU Yuli 4 & XIE Shengli 4 1. Department of Control science & Control Engineering, Huazhong university of science & technology, wuhan 430074, china 2. school of automation, wuhan university of science & technology, wuhan 43.070, china 3. school of Information, Central South university of Economy, Politics and Law, wuhan 430064, china 4. school of Electronics & Information Engineering, South china university of technology, Guangzhou 510640, china Correspondence should be addressed to Liao Xiaoxin (email: xiaoxin_liao@***) Department of Control science & Control Engineering Huazhong University of Science & Technology Wuhan China school of automation Wuhan University of Science & Technology Wuhan China school of Information Central South University of Economy Politics and Law Wuhan China school of Electronics & Information Engineering South China University of Technology Guangzhou China

Constructing a family of generalized Lyapunov functions, a new method is proposed to obtain new global attractive set and positive invariant set of the Lorenz chaotic system. The method we proposed greatly simplifies the complex proofs of the two famous estimations presented by the Russian scholar Leonov. Our uniform formula can derive a series of the new estimations. Employing the idea of intersection in set theory, we extract a new Leonov formula-like estimation from the family of the estimations. With our method and the new estimation, one can confirm that there are no equilibrium, periodic solutions, almost periodic motions, wandering motions or other chaotic attractors outside the global attractive set. The Lorenz butterfly-like singular attractors are located in the global attractive set only. This result is applied to the chaos control and chaos synchronization. Some feedback control laws are obtained to guarantee that all the trajectories of the Lorenz systems track a periodic solution, or globally stabilize an unstable (or locally stable but not globally asymptotically stable) equilibrium. Further, some new global exponential chaos synchronization results are presented. Our new method and the new results are expected to be applied in real secure communication systems.

关键词： Lorenz chaotic system global attractive set positive invariant set globally exponential tracking globally exponential synchronization.

β-Sialon Produced by Carbon Thermal Nitriding Reaction of Bauxite

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2000年第3期14卷 209-213页

作者： Jun Wang, Nan Li, Caicheng Shi, Chengchang Jia ( Material science and Engineering school, {2. of science and technology Beijing, Beijing 100083, china Material science and Engineering school, wuhan {2. of science and technology, wuhan 430 Material science and Engineering school University of Science and Technology Beijing Beijing 100083 China Material science and Engineering school Wuhan University of Science and Technology Wuhan 430081 China

β-Sialon was produced by carbon thermal nitriding reaction in N_2.gas atmosphere when the mixtures of bauxite and anthracite were put into vertical furnace. According to the mass loss of raw materials and the result of X-ray diffration (XRD) of products, the influences of the process parameters on the compositions and relative contents of products, such as the fixed carbon content, the flow of N2. the soaking time and the temperature, were researched.

关键词： β-Sialon bauxite anthracite carbon thermal nitriding processing parameter vertical furnace