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3D thermo-hydro-mechanical-migratory coupling model and FEM analyses for dual-porosity medium

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Science china(Technological Sciences) 2010年第8期53卷 2172-2182页

作者： ZHANG YuJun 1&ZHANG WeiQing 2.1 State Key Laboratory of Geomechanics and Geotechnical engineering,Institute of Rock and Soil Mechanics, Chinese Academy of Sciences,Wuhan 430071,china 2.2. of civil engineering,Southwest jiaotong university,Chengdu 610031,china 1. State Key Laboratory of Geomechanics and Geotechnical engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China2. School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China

One kind of 3D coupled thermo-hydro-mechanical-migratory model for saturated-unsaturated dual-porosity medium was established,in which the stress field and the temperature field are single,but the seepage field and the concentration field are double,and the influences of sets,spaces,angles,continuity ratios,stiffness of fractures on the constitutive relationship of the medium can be *** relative three-dimensional program of finite element method was also *** comparing with the existing computation example,reliability of the model and the program were *** a hypothetical nuclear waste repository as a calculation example,the radioactive nuclide leak was simulated numerically with both the rock mass and the buffer being unsaturated media,and the temperatures,negative pore pressures,flow velocities,nuclide concentrations and normal stresses in the rock mass were *** results showed that the temperatures,negative pore pressures and nuclide concentrations in the buffer all present nonlinear changes and distributions that even though the saturation degree in porosity is only about 1/9 of that in fracture,the flow velocity of underground water in fracture is about 6 times of that in porosity because the permeability coefficient of fracture is almost four orders higher than that of porosity,and that the regions of stress concentration occur at the vicinity of two sides of the boundary between buffer and disposal pit wall.

关键词： dual-porosity medium thermo-hydro-mechanical-migratory coupling three-dimensional model FEM analysis

A method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed presses

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Journal of Pharmaceutical Analysis 2009年第3期21卷 141-148页

作者： Jun Wang1 ,Sheng-dun Zhao1 ,Hu-shan Shi1 ,Chun-jian Hua2.. school of Mechanical engineering,Xi’an {2. university,Xi’an 710049 2. school of Mechanical engineering,Southern Yangtze university,Wuxi 2.412.,china. school of Mechanical engineering Xi'an Jiaotong University Xi'an 710049 China school of Mechanical engineering Southern Yangtze University Wuxi 214122 China

A new method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed mechanical presses was put forward. By analyzing the kinematic characteristics of a center-located slider-crank mechanism whose crank rotates at a constant angular velocity,the kinematic parameters of the slide,connecting rod and crank were formulated approximately. On the basis of the results above,three inertia forces and the input moment in the mechanism during its idle running were investigated and formulated by dynamic analysis. A verification experiment was performed on a slider-crank mechanism at a high-speed press machine. The forces derived from the established formulas were compared respectively with those obtained by the ADAMS software and the classical method of connecting rod mass substitution. It was experimentally found that the proposed formulas have an improved performance over related earlier techniques. By use of these results,a 1 000 kN 1 2.0 rpm four-point high-speed press machine was designed and manufactured. The slide of this press is driven by four sets of slider-crank mechanisms with symmetrical layout and opposite rotation directions to counterbalance the horizontal inertia forces. Four eccentric counterbalance blocks were designed to counterbalance the vertical force after their mass and equivalent eccentric radius were formulated. The high-speed press machine designed by the proposed counterbalance method has worked with satisfactory performance and good dynamic balance for more than four years in practical production.

关键词： slider-crank mechanism kinematics inertia force counterbalance high-speed press

Experimental study on drying of typical MSW under incinerator-like conditions

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Science china(Technological Sciences) 2007年第5期50卷 636-643页

作者： ZHANG YanGuo1, CHEN MeiQian2. MENG AiHong1, LI QingHai1 & CHEN YunXuan2.1 Key Laboratory for Thermal Science and Power engineering of Ministry of Education, Tsinghua university, Beijing 100084,{2. 2.school of Mechanical, Electronical and Control engineering, Beijing jiaotong university, Beijing 100044,{2. 1. Key Laboratory for Thermal Science and Power engineering of Ministry of Education Tsinghua University Beijing 100084 China 2. school of Mechanical Electronical and Control Engineering Beijing Jiaotong University Beijing 100044 China

In this paper, a series of experiments were conducted to investigate the drying of typical municipal solid wastes (MSW) in a muffle incinerator. From the experimental drying characteristic curves, the effects of temperature on drying process were observed to be more obvious in the low temperature region than in the high tem- perature region in muffle incinerator. At a specified drying temperature, drying time was highly dependent upon the packed waste thickness, having an exponent rela- tion with the thickness. When the drying temperature increased or the thickness of potato bulks was diminished, the maximum drying rate reduced. Based on the first-order reaction, activation energy (Ea), and factor A of potato and cabbage were determined.

关键词： drying, MSW, potato blocks, cabbage stems, temperature, dying rate

VIBRATION AND CONTROL IN RING ROLLING PROCESS

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中国有色金属学会会刊：英文版 1999年第2期9卷 9-13页

作者： Hua Lin1, 2. Mei Xuesong2.and Wu Xutang2.1 school of Materials Science and engineering,Wuhan Automotive Polytechnic {2., Wuhan 430070, P. R. china2.school of Mechanical engineering,Xian jiaotong {2., Xian 710049, P. R. china 武汉汽车工业大学材料科学与工程学院湖北武汉西安交通大学机械工程学院陕西西安

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关键词： ring rollingvibrationstabilityprocess control

Stability for a class of nonlinear time-delay systems via Hamiltonian functional method

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Science china(Information Sciences) 2012年第5期55卷 1218-1228页

作者： YANG RenMing 1,2.& WANG YuZhen 1 1 school of Control Science and engineering,Shandong {2.,Jinan 2.0061,china 2.Shandong jiaotong {2.,Jinan 2.002.,china 1. school of Control Science and engineering Shandong University Jinan 250061 China2. Shandong Jiaotong University Jinan 250023 China

This paper investigates the stability of a class of nonlinear time-delay systems via Hamiltonian functional method,and proposes a number of new results on generalized Hamiltonian realization (GHR) and stability analysis for this class of ***,the concept of GHR of general nonlinear time-delay systems is proposed,and several new GHR methods are ***,based on the new GHR methods obtained,the stability of time-delay systems is investigated,and several delay-dependent sufficient conditions in term of matrix inequalities are derived for the stability analysis by constructing suitable Lyapunov-Krasovskii (L-K) ***,an illustrative example shows that the results obtained in this paper have less conservatism,and work very well in the stability analysis of some nonlinear time-delay Hamiltonian systems.

关键词： nonlinear time-delay systems stability Hamiltonian functional method generalized Hamiltonian realization

WPT-Based Modal Control on Distributed Structures with MRF-04K Damper

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Transactions of Tianjin university 2011年第6期17卷 397-403页

作者：林伟李忠献张根明黄鹏云 school of civil {2. Fuzhou University school of civil {2. Tianjin University

The magnetorheological （MR） fluid damper-based semiactive control systems have received considerable attention for protecting structures against natural hazards such as strong earthquakes and high winds. In this paper, a novel modal controller using wavelet packet transform （WPT） is proposed for the vibration control of distributed structures. In the proposed control system, the WPT method is utilized to decompose the acceleration measurement and select the modes containing most of the WPT energy component as the dominant modes. Then, a modal controller is designed to control the dominant modes and the optimal active control force is solved. Finally, Clipped-optimal con- trol law is adopted to determine the voltage applied to each MR damper. A Kalman-filter observer, which estimates the full controlled modal states from local accelerometer feedbacks, is designed for rendering the controller to be more applicable to distributed structures with a large number of degrees of freedom. A numerical example of a stadium root structure installed with MRF-04K damper is presented. The effectiveness of the controller is evaluated under both Tianjin and E1 Centro earthquake excitations. The superior performance and adaptability of the controller for versatile loading conditions are demonstrated through the comparison with traditional truncated modal controller.

关键词： distributed structure modal control semiactive control wavelet packet transform magnetorheological (MR) damper Kalman-filter

Vision navigation algorithm for mine agent based on quaternion

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中国有色金属学会会刊：英文版 2011年第S3期21卷 610-615页

作者： LI Ke-zhao1, 4, LEI Wei-wei1, 2. GUO Zeng-zhang1, 2. WU Li-xin3, ZHANG Qin4 1. school of Survey and Land Information engineering, Henan Polytechnic {2., Jiaozuo 454003, china 2. Key Laboratory of Mine Spatial Information Technologies of State Bureau of Surveying and Mapping, Henan Polytechnic {2., Jiaozuo 454003, china 3. College of Resources and civil engineering, Northeastern {2., Shenyang 110819, china 4. College of Geology engineering and Geomatics, Chang’an {2., Xi’an 710054, china [a] school of Survey and Land Information engineering Henan Polytechnic University Jiaozuo 454003 China [b] Key Laboratory of Mine Spatial Information Technologies of State Bureau of Surveying and Mapping Henan Polytechnic University Jiaozuo 454003 China [c] College of Resources and civil engineering Northeastern University Shenyang 110819 China [d] College of Geology engineering and Geomatics Chang'an University Xi'an 710054 China

Autonomous relative navigation is the key technology in mining or rescuing. On the basis of mine requirement and the theories of machine vision, an autonomous relative navigation algorithm for mine agent based on quaternion was proposed. In rotation transformation, this algorithm was represented by using quaternion. Because the Jacobi matrix of this method is lower than that of Hall algorithm, the calculation efficiency is improved by using this algorithm. The results of these experiments show that the computation burden of this algorithm based on quaternion is about half that of Hall algorithm. This algorithm based on quaternion is improved as a valid way to solve the problem of mine real-time navigation.

关键词： quaternion mine agent vision navigation

Effect of Recycled Coarse Aggregate on Concrete Compressive Strength

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Transactions of Tianjin university 2011年第3期17卷 229-234页

作者：汪振双王立久崔正龙周梅 school of Hydraulic engineering Dalian University of Technology College of civil engineering and {2. Liaoning Technical University

The effect of recycled coarse aggregate on concrete compressive strength was investigated based on the concrete skeleton theory. For this purpose, 30 mix proportions of concrete with target cube compressive strength ranging from 2. to 60 MPa were cast with normal coarse aggregate and recycled coarse aggregate from different strength parent concretes. Results of 2.-d test show that the strength of different types of recycled aggregate affects the concrete strength obviously. The coarse aggregate added to mortar matrix plays a skeleton role and improves its compressive strength. The skeleton effect of coarse aggregate increases with the increasing strength of coarse aggregate, and normal coarse aggregate plays the highest, whereas the lowest concrete strength occurs when using the weak recycled coarse aggregate. There is a linear relationship between the concrete strength and the corresponding mortar matrix strength. Coarse aggregate skeleton formula is established, and values from experimental tests match the derived expressions.

关键词： recycled coarse aggregate compressive strength concrete skeleton model skeleton formula crushing index

Semi-solid Casting of High Speed Steel Ingots Using Inclined Slope Pre-crystallization Method

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Journal of Wuhan university of Technology(Materials Science) 2009年第5期24卷 750-752页

作者：和优锋 State Key Laboratory for Fabrication and Process of Nonferrous Metals General Research Institute for Nonferrous Metals

Semi-solid casting of M2.high speed steel ingots was investigated by inclined slope pre-crystallization method. Effects of casting temperature and slope length on the microstructure of M2.HSS ingots were investigated. M2.cast ingots of non-dendritic primary austenite and fine eutectic ledeburite network carbide structure were obtained, with the casting temperature, slope length and angle of 1480 ℃, 500 mm and 60° respectively. Meanwhile, the microstructure of cast samples was quantitatively assessed by Image tool software. Results show that optimum mean equivalent diameter of primary austenite crystal grain is 50.8 μm, shape factor is 0.83, and mean thickness of network carbide is 5.2. μm.

关键词： M2.high speed steel semi-solid pre-crystallization inclined slope