检索结果-南通市图书馆

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,wuhan university of technology,wuhan 430070,china 1. School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 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

Development of Mathematical Model on Preparation of Functionally Graded Material by Co-sedimentation

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & technology 2001年第2期17卷 275-277页

作者： Zhongmin YANG, Lianmeng ZHANG and Qiang SHEN Institute of Materials Science and Engineering, wuhan university of technology, wuhan 430070, china wuhan Univ Technol Inst Mat Sci & Engn Wuhan 430070 Peoples R China

From the process of sedimentation the mathematical relationships among deposition Volume and powder properties as well as sedimentation parameters were deduced. Based on the formula a mathematical model was set up and simulated through the computer. At last the validity of mathematical model was supported by the representative experiment on Ti-Mo system FGM prepared by co-sedimentation.

关键词： Co Mo Development of Mathematical Model on Preparation of Functionally Graded Material by Co-sedimentation

TiO_2 thin film photocatalyst

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2004年第4期23卷 289-295页

作者： YUJiaguo StateKeyLaboratoryofAdvancedtechnologyforMaterialsSynthesisandProcessing WuhanUniversityofTeclmologyWuhan430070China

It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties of TiO_2 thin films. Therefore, it is necessary toelucidate the influence of the preparation process and post-treatment conditions on thephoto-catalytic activity and surface microstructures of the films. This review deals with thepreparation of TiO_2 thin film photo-catalysts by wet-chemical methods (such as sol-gel,-reversemicellar and liquid phase deposition) and the comparison of various preparation methods as well astheir advantage and disadvantage. Furthermore, it is discussed that the advancement ofphotocatalytic activity, super-hydrophilicity and bactericidal activity of TiO_2 thin filmphotocatalyst in recent years.

关键词： inorganic non-metal materials TiO_2 thin films preparation sol-gel method liquid phase deposition method reverse micellar method photocatalytic activity super-hydrophilicity bactericidal activity

Synthesis of Cr-Al_2O_3 Cermet Selective Surfaces Coated by SnO_2 Thin Film by Air Plasma Spraying

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2012年第S1期41卷 272-275页

作者： Zhu Zhenqi,Cheng Xudong,Li Guanglei School of Materials Science and technology,wuhan university of technology,wuhan 430070,china wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Sch Mat Sci & Technol Wuhan 430070 Peoples R China

High efficient Cr-Al2O3 cermet selective surfaces coated by sol-gel SnO2 thin film for high-temperature application were synthesized by air plasma spraying(APS),followed further heat and polish *** phase composition and micro morphology of coating samples were characterized by X-ray diffractions(XRD),scanning electron microscope(SEM)and roughmeter *** solar absorptance(α)and thermal emittance(ε)were determined by optical spectrum *** results show that Cr-Al2O3 cermet coating has a high absorptivity nearly *** unfortunately,the emissivity of these coatings is nearly 0.50 because of the big thickness and coarse surface prepared by APS ***,once coated SnO2 thin film,the composite coatings exhibit excellent selective absorbing property of α=0.89 and ε=***,SnO2 thin film plays a significant role in decreasing the emissivity of coatings as antireflection *** furthermore,the optical performance shows that more metal content and smooth surface are favorable for the selective absorbing ***,the coatings have excellent bond strength with stainless steel substrate and thermal shock resistance at high temperature.

关键词： selective surfaces SnO2 thin film air plasma spraying

Mold Filling Analysis in Vacuum Infusion Molding Process Based on a High-Permeable Medium

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5期19卷 467-471页

作者： Yingdan ZHU, Hua TAN and Jihui WANGState Key Laboratory of Advanced technology for Materials Synthesis and Processing, wuhan university of technology, wuhan 430070, china State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulat... 详细信息

关键词： Vacuum infusion molding process (VIMP) High-permeable medium Mold filling Simulation

Numerical simulations and experimental investigations on transverse effects of two-wave mixing in a photovoltaic photorefractive crystal

在线全文

学校读者我要写书评

暂无评论

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 Science and Engineering,Huazhong university of Science and technology,wuhan 430074,china 2 School of Science,wuhan university of technology,wuhan 430070,china 1. wuhan National Laboratory for Optoelectronics School of Optoelectronic Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China2. School of Science Wuhan University of Technology Wuhan 430070 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

XPS Analysis of Ni and Oxygen in Single-Sintered SrTiO_3 Multifunction Ceramic

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & technology 2001年第5期17卷 535-537页

作者： Qing XU, Wen CHEN and Runzhang YUAN State Key Laboratory of Advanced technology for Materials Synthesis and Processing, wuhan university of technology, wuhan 430070, china wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China

XPS analyses have been performed to investigate the chemical conditions of Ni and oxygen on grain surfaces in single-sintered SrTiO3 capacitor-varistor ceramic doped with Nb2O5 and NiO. It is ascertained that Ni is in form of Ni2+ ions, which substitute for Ti4+ ions on grain surfaces during the oxidizing annealing. Moreover, it is confirmed that three kinds of chemically adsorbed oxygen such as O2-, O- and O-2(-) are formed on grain surfaces. It is proposed that these behaviors contribute greatly to the generation of multiple types of grain boundary acceptor states in the ceramic.

关键词： XPS Analysis of Ni and Oxygen in Single-Sintered SrTiO3 Multifunction Ceramic Ni

Exploring non-equilibrium statistical ensembles

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2011年第34期56卷 3654-3660页

作者： BI Qiao & LIU Jie Department of Physics, School of Science, wuhan university of technology, wuhan 430070, china Department of Physics School of Science Wuhan University of Technology

Since Gibbs synthesized a general equilibrium statistical ensemble theory, generalizing the Gibbsian theory to non-equilibrium phenomena has been a dream for some theorists. However, the status of the theory for the non-equilibrium ensemble formalism is not as well established as the Gibbsian ensemble theory. In this work, we explore the formalism behind the non-equilibrium statistical ensemble theory based on the sub-dynamic kinetic equation originating from the Brussels-Austin school and developed further by others. The key is establishing a similarity transformation between Gibbsian ensembles and the sub-dynamic ensemble. Using this way, we study a spin-Boson model with strong coupling. A reduced density operator for the canonical ensemble can be easily obtained and the relevant decoherence-free property is revealed.

关键词： subdynamics statistical ensemble non-equilibrium statistical physics

NONLOCAL THEORY STUDY ON FRACTURE TOUGHNESS OF CERAMIC MATERIALS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1996年第4期9卷 256-262页

作者： X.H.Song(Centre for Materials Research and Analysis,wuhan university of technology,wuhan 430070,china )

The theoretical calculation formulas for the plane strain fracture toughness of mode Ⅰand Ⅱcracks of ceramic materials are deduced in this paper by using the nonlocal elasticity theory and maximum tensile stress criterion The deduced formulas, which are independent of crack geometry,bear a relation to material *** is shown through experiment that the theoretical value of fracture toughness is the lower limit of testing value. The theoretical calculation formulas for fracture toughness relate the macro-mechanical performance of materials with the micro-structural parameters and,therefore, are beneficial to fully understanding the physical mechanism of material rupture.

关键词： nonlocal elasticity theory fracture toughness,ceramic material