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Bionic Design and Finite Element Analysis of Elbow in Ice Transportation Cooling System

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Journal of Bionic engineering 2010年第3期7卷 301-306页

作者： Dejun Miao~(1,2., Xiuhua Sui~3. Linjing Xiao~3.1. Key Laboratory of Mine Hazard Prevention and Control (Ministry of Education, china), Shandong University of science and Technology, Qingdao 2.6510, P. R. china 2. School of Architecture, Tsinghua University, {3. 100084, P. R. china 3. College of Mechanical and Electronic engineering, Shandong University of science and Technology, Qingdao 2.6510, P. R. china [a] Key Laboratory of Mine Hazard Prevention Control (Ministry of Education China) Shandong University of Science Technology Qingdao 266510 P. R. China [b] School of Architecture Tsinghua University Beijing 100084 P. R. China [c] College of Mechanical Electronic engineering Shandong University of Science Technology Qingdao 266510 P. R. China

With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical problem; typically flowresistance occurs in the elbow. In the present study, according to the analysis of the surface morphology of fish scale, abiomimetic functional surface structure for the interior wall of elbow is designed. Based on the theory of liquid-solid two phaseflow, a CFD numerical simulation of ice-water mixture flowing through the elbow is carried out using finite element *** experiments of pressure drop and flow resistance for both bionic and common elbows are conducted to test theeffect of the bionic elbow on flow resistance reduction. It is found that with the increase in the ice mass fraction in the ice-watermixture, the effect of bionic elbow on resistance reduction becomes more obvious.

关键词： bionic elbow two phase flow ice transportation flow resistance reduction pressure loss

THE APPLICATION OF DISCRETE ELEMENT METHOD IN SOLVING THREE-DIMENTIONAL IMPACT DYNAMICS PROBLEMS

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Acta Mechanica Solida Sinica 2003年第3期16卷 256-261页

作者： Liu Kaixin Gao Lingtian (Department of mechanics and engineering {2.,Peking University,{3. 100871,china) Department of mechanics and engineering {2. Peking University Beijing 100871 China

A three-dimensional discrete element model of the connective type is presented. Moreover,a three-dimensional numerical analysis code,which can carry out the transitional pro- cess from connective model(for continuum)to contact model(for non-continuum),is developed for simulating the mechanical process from continuum to *** wave propagation process in a concrete block(as continuum)made of cement grout under impact loading is numer- ically simulated with this *** comparing its numerical results with those by LS-DYNA,the calculation accuracy of the model and algorithm is ***,the failure process of the concrete block under quasi-static loading is demonstrated,showing the basic dynamic tran- sitional process from continuum to *** results of calculation can be displayed by *** damage modes are similar to the experimental *** two numerical examples above prove that our model and its code are powerful and efficient in simulating the dynamic failure problems accompanying the transition from continuum to *** also shows that the discrete element method(DEM)will have broad prospects for development and application.

关键词： discrete element method three-dimensional model impact stress wave dynamic failure

Synthesis and thermodynamic analysis of nano-La2.3

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Progress in Natural science:Materials International 2007年第7期17卷 838-844页

作者： Liu Lili~(1,2. Tang Jie~2.Li Yuxiang~1 Zhang Mei~(1**) Wang Xidong~(1,3. (1.Department of Physical Chemistry,University of science and Technology {3.,{3. 100083.{3. 2.National Institute for Materials science,Segen 1-2.1,Tsukuba 3.5-0047,Japan 3.College of engineering,{3. University,{3. 100871,{3.) [a]Department of Physical Chemistry University of Science and Technology Beijing Beijing China [b]National Institute Materials science Tsukuba Jpan [c]College of engineering Beijing University Beijing China

The thermodynamic parameters of La（NO3.3.nd La（OH）3.re evaluated and the thermodynamics of nano-La2.3.yn- thetic process is *** the base of thermodynamic analysis,La2.3.ano-powders are prepared by the sol-gel method and the experi- ment scheme is designed by an orthogonal *** dry-gelatin is analyzed with differential thermal analysis/thermo-gravimetric analy- sis（TGA-DTA）and X-ray diffraction *** microstructure of nano-La2.3.owders is observed by transmission dectron micro- *** synthetic parameters affecting the average grain size and dispersivity of nano-La2.3.articles are experimentally examined and *** the results indicate that nano-La2.3.articles well-dispersed are obtained and the average grain size is in the range of 2.—50 nm.

关键词： nano-La2.3 sol-gel thermodynamic analysis

Experimental and discrete element numerical analysis of side slope instability induced by fissure water underlying impervious bed

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science china(Technological sciences) 2005年第z1期48卷 65-80页

作者： LIU Bingshan1, LI Shihai1, ZHANG Lei1,2.& WANG Jianguo3.. Institute of mechanics, Chinese Academy of sciences, {2. 100080,{3. 2. Graduate School, Chinese Academy of sciences, {2. 100060,{3. 3. Tropical Marine science Institute, National University of Singapore, 10 Kent Ridge Crescent, Singapore 1192.0 Chinese Acad Sci Inst Mech Beijing 100080 Peoples R China Chinese Acad Sci Grad Sch Beijing 100060 Peoples R China Natl Univ Singapore Trop Marine Sci Inst Singapore 119260 Singapore

When the sliding mass contains impervious bed, rainfall can infiltrate into mountain via crevices and form higher artesian aquifer at impervious bed inferior. This will decrease slip resistance and increase sliding forces of the sliding mass, thus lowering the safety factor, and inducing landslide disasters. In this paper, a landslide experimental apparatus is designed for experimental studies on the mechanism of this type of landslides. Meanwhile, the non-dimensional parameters in the model experiment are taken into account using dimensional analysis. The experimental results show that (1) the ratio of the cleft water pressure to the overlying pressure is a crucial parameter affecting the stability of the slope; (2. when the shut-in pressure reaches 80% of the normal component of the pressure on the slip surface made up of rock and soil, landslide will occur; (3. the whole slope will start to slide when the shut-in pressure is equal to the normal component of the pressure formed by the overlying rock and soil on the upper 3.% area. In this article, a discrete element method simulation is used to investigate the influence of cleft water pressure and shearing strength on the landslide stability. It can be concluded that the critical value of Ccr, ?cr, which determines the slide mass stability, increases with the increase of the water pressure; if the water pressure reaches a high level, the stability of the slide mass depends mainly on C, while the influence of ? becomes smaller than C.

关键词： impervious bed, rainfall infiltration, pore water pressure, landslide experiment, displacement monitor, discrete element method.

New adaptive quasi-sliding mode control for nonlinear discrete-time systems

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Journal of Systems engineering and Electronics 2008年第1期19卷 154-160页

作者： Wang Weihong1,2.& Hou Zhongsheng3.1. School of Tra?c and Transportation, beijing Jiaotong Univ., beijing 100044, P. R.{2. 2. Dept. of Automation, Taiyuan Univ. of {3. & Technology, Taiyuan 03.02., P. R.{2. 3. Advanced Control Systems Lab, School of Electronics and Information engineering, beijing Jiaotong Univ., beijing 100044, P. R.{2. [a]School of Traffic and Transportation Beijing Jiaotong Univ. Beijing 100044 P. R. China [b]Dept. of Automation Taiyuan Univ. of Science & Technology Taiyuan 030024 P. R. China [c]Advanced Control Systems Lab School of Electronics and Information Engineering Beijing Jiaotong Univ. Beijing 100044 P. R. China

A new adaptive quasi-sliding mode control algorithm is developed for a class of nonlinear discrete-time systems, which is especially useful for nonlinear systems with vaguely known dynamics. This design is model-free, and is based directly on pseudo-partial-derivatives derived on-line from the input and output information of the system using an improved recursive projection type of identification algorithm. The theoretical analysis and simulation results show that the adaptive quasi-sliding mode control system is stable and convergent.

关键词： quasi-sliding mode control adaptive control model-free control pseudo-partial-derivative

Vertical quantitative and dominant population distribution of the bacteria isolated from the Muztagata ice core

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science china Earth sciences 2005年第10期48卷 1728-1739页

作者： XIANG Shurong1, YAO Tandong1, 2. AN Lizhe1, 3. WU Guangjian2. XU Baiqing2. MA Xiaojun 3. LI Zhen1, WANG Junxia1 & YU Wusheng1 1. Key Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and {3. Research Institute, Chinese Academy of sciences, Lanzhou 73.000,{2. 2. Institute of Tibetan Plateau Research, Chinese Academy of sciences, beijing 100085,{2. 3. College of Life science, Lanzhou University, Lanzhou 73.000,{2. Key Laboratory of Ice Core and Cold Regions Environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China Institute of Tibetan Plateau Research Chinese Academy of sciences beijing{2. College of Life science Lanzhou University Lanzhou china

Vertical distribution of the main bacteria isolated from the Muztagata ice core (about 2..4 m) was investigated by means of cultivation and 16S rRNA sequence analysis. The results showed that the amount of culturable bacteria fluctuated with ice core depth, and was more in dirty layer than in clean ice, which suggested the close corresponding relationship between high input of the bacteria deposited by wind and snowflow and dirty layer. Most of the bacteria were psychrophiles and psychrotolerants, including α- and γ-proteobacteria, Cryobacterium psychro-philum, CFB (Cytophaga-Flavobacterium-Bacteroides) group, high-G+C gram-positive bacteria (HGC). Acinetobacter sp. and HGC repeatly occurred in different ice depths, and their quantita-tive distribution was consistent with the change of the total amount of culturable bacteria with depth, which suggested the main bio-indicator; while Flavobacterium, Cryobacterium psychro-philum, and α-proteobacteria, also functioned as a secondary indicator of climatic and environ-mental changes. This study is the first report concerning continuous quantitative variation and pattern of the main culturable bacteria in ice core section.

关键词： Pamirs Plateau, ice core, pattern of bacteria, bio-indicator.

Relationship between surface subsidence factor and mining depth of strip pillar mining

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中国有色金属学会会刊：英文版 2011年第S3期21卷 594-598页

作者： GUO Wen-bing1, 2. HOU Quan-lin 1, ZOU You-feng2.1. College of Earth science, Graduate University of Chinese Academy of sciences, {2. 100049,{3. 2. School of Energy science and engineering, Henan Polytechnic University, Jiaozuo 454000,{3. Chinese Acad Sci Coll Earth Sci Grad Univ Beijing 100049 Peoples R China Henan Polytech Univ Sch Energy Sci & Engn Jiaozuo 454000 Peoples R China

Strip pillar mining is one of the most important technical measures to control mining subsidence in china. Mining depth is one of the most important factors that can affect the mining subsidence in strip pillar mining. Six numerical simulation models were set up to simulate the surface subsidence of strip pillar mining in different mining depths. The mining depth in these six models ranges from 3.0 to 800 m. The simulated results were compared and analyzed. The formula was established based on the simulated results. It demonstrated that the subsidence of strip pillar mining method is related to mining depth. While the other conditions are the same, the subsidence of strip pillar mining increases with the increase of mining depth by logarithmic relationship.

关键词： subsidence factor strip pillar mining mining depth numerical simulation

Preparation of Pt/K_2.a_2.i_3._(10) and its photo-catalytic activity for hydrogen evolution from methanol water solution

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science china Chemistry 2006年第2期49卷 162-168页

作者： CUI Wenquan1,3. LIU Li2. FENG Liangrong1, XU Chenghua1, LI Zijian1, Lü Shaojie1 & QIU Fali1 1. Chengdu Institute of Organic Chemistry, Chinese Academy of sciences, Chengdu 610041, china 2. Chemistry Department, Sichuan University of science & {3., Zigong 643.3., china 3. Graduate School of the Chinese Academy of sciences, beijing 10003., china Correspondence should be addressed to Qiu Fali 1. Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu 610041 China 3. Graduate School of the Chinese Academy of sciences Beijing 100039 China 2. Chemistry Department Sichuan University of Science & Engineering Zigong 643033 China

A layered perovskite-type oxide K2.a2.i3.10 was prepared with high-temperature solid-state reaction, and characterized with X-ray diffraction (XRD) and ultraviolet-visible diffuse re-flectance spectroscopy (UV-Vis DRS). Platinum was loaded onto K2.a2.i3.10 as a co-catalyst with different methods. The dispersion of platinum on K2.a2.i3.10 was determined with HOT method. The photocatalytic activity of Pt/K2.a2.i3.10 was studied. This catalyst showed much higher activity in hydrogen evolution reaction than Ni/K2.a2.i3.10. The effects of different amounts of loaded platinum and several preparation methods were evaluated. The best achieved hydrogen evolution rate was 2.3.88 μmol·h?1 by Pt(2.)/K2.a2.i3.10. A possible band structure and mechanism were discussed based on the results.

关键词： photocatalysis hydrogen platinum K_2.a_2.i_3._(10) support

On Catastrophe and Cavitation for SphericalCavity

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Communications in Nonlinear science and Numerical Simulation 1999年第4期4卷 249-254页

作者： Ming JIN Kefu HUANG Jike WU(Department of mechanics and engineering {2., Peking University,{3.,china) Department of mechanics and engineering {2. Peking University Beijing 100871 China

IntroductionInrecelltyears,theresearchesoncavitationandcatastropheofacavitysu***therwithbifllrcationtheory... 详细信息

IntroductionInrecelltyears,theresearchesoncavitationandcatastropheofacavitysu***therwithbifllrcationtheory...

关键词： nonlinearity bifurcation Hooke material