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An adaptive version of ghost-cell immersed boundary method for incompressible flows with complex stationary and moving boundaries

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science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 923-932页

作者： WANG Liang1 & WU ChuiJie2.3 1 School of science,PLA University of science and {2.,Nanjing 2.1101,china 2.State Key laboratory of Structural Analysis for Industrial Equipment,Dalian University of {2.,Dalian 11602.,china 3 School of Aeronautics and Astronautics,Dalian University of {2.,Dalian 11602.,china 1. School of science PLA University of Science and Technology Nanjing 211101 China2. State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China3. School of Aeronautics and Astronautics Dalian University of Technology Dalian 116024 China

An adaptive version of immersed boundary method for simulating flows with complex stationary and moving boundaries is *** method employs a ghost-cell methodology which allows for a sharp representation of the immersed *** simplify the implementation of the methodology,a volume-of-fluid method is introduced to identify the immersed *** addition,the domain is spatially discretized using a tree-based discretization which is relatively simple to implement a fully flexible adaptive refinement ***,the methodology is validated by comparing it with numerical and experimental results on three cases:(1) the flow passing a circular cylinder at Re=40 and Re=100,(2. a periodic oscillation of a circular cylinder in fluid at rest and(3) the self-propelled fish-like swimming at Re=6400.

关键词： adaptive mesh refinement ghost-cell immersed boundary method moving boundaries

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

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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 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

Multi-dimensional project management models for mega-construction companies and their applications

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science china(Technological sciences) 2011年第S1期54卷 118-124页

作者： LIN ZhengHang 1,2.QIANG MaoShan 1,2.TANG WenZhe 1,2.FAN QiXiang 3 &LIU Qiang 4 1 Institute of Project Management and Construction technology,tsinghua University,Beijing 100084,{2. 2.State Key laboratory of Hydraulic and Engineering,tsinghua University,Beijing 100084,{2. 3 china Three Gorges Corporation,Yichang 443002.{2. 4 School of Software,tsinghua University,Beijing 100084,{2. 1. Institute of Project Management and Construction technology Tsinghua University Beijing 100084 China2. State Key Laboratory of Hydraulic and Engineering Tsinghua University Beijing 100084 China3. China Three Gorges Corporation Yichang 443002 China4. School of Software Tsinghua University Beijing 100084 China

china is undertaking an increasing number of mega-infrastructure projects along with its rapid economic *** participants in these projects,understand how to adapt the proper and efficient management strategies is *** this paper,we propose three distinct models for companies under various background and management requirements,based on sophisticated data analysis and model ***,we successfully committed these models with hydropower development projects and achieved a great progress in enhancing management efficiency.

关键词： project management models mega-construction companies applications hydropower development companies

Turbulent intensity and its similarity function over an Inner Mongolian grassland during spring

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science china Earth sciences 2010年第5期53卷 773-780页

作者： YUE Ping1,2.3, NIU ShengJie2. HU YinQiao4 & ZHANG Qiang1 1 Key laboratory of Arid Climate Change and Reducing Disaster of Gansu Province, Key laboratory of Arid Climate Change and Reducing Disaster of CMA, Institute of Arid Meteorology, CMA, Lanzhou 73002.,{2. 2.Nanjing University of information science and technology, Nanjing 2.0044,{2. 3 Zhangye national Meteorological Observatory, Zhangye 734000,{2. 4 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of science, Lanzhou 730000,{2. 1. Key laboratory of Arid Climate Change and Reducing Disaster of Gansu Province Key Laboratory of Arid Climate Change and Reducing Disaster of CMA Institute of Arid Meteorology CMA Lanzhou 730020 China2. Nanjing University of Information Science and Technology Nanjing 210044 China3. Zhangye National Meteorological Observatory Zhangye 734000 China4. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Science Lanzhou 730000 China

Macroscopic reason for the development of turbulences in fluid is the conjunction action of velocity and temperature shears. We use the 2.08 spring flux observations in the surface layer over Inner Mongolian grassland, obtain the similarity functions of turbulent intensity under different stratification stability conditions, and calculate the clear day turbulent intensity in the spring, which is then analyzed and compared with the observed values of turbulent intensity. The results show that in the Inner Mongolian grassland, under the condition of spring unstable stratification of the surface layer, dependence of the similarity function of turbulent intensity on stratification stability follows a "2.3 power law". The structural function is a constant under the neutral stratification condition, and complicated under the stable condition. The calculated turbulent intensity has a close correlation with the observed one, which verifies the accuracy of the similarity functions and the suitability of the theorem of turbulent intensity in the grassland region.

关键词： turbulent intensity variance of velocity similarity function grassland

A Feedback Scheme for Fountain Codes Based Transport Protocol in Space Communications

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china Communications 2015年第8期12卷 62-72页

作者： XING Yanling GE Ning tsinghua national {2. for information science and technology Department of Electronic Engineering Tsinghua University Aerospace Communications and Terminal Application Technologies Engineering laboratory in Shenzhen

This paper proposed a practical- feedback scheme for fountain codes based transportprotocol in space communications. In the proposed scheme, the sender is signaled by two types of acknowledgment （ACK） *** decoding, packet loss probability isestimated on the receiver side and encapsulated intoa soft ACKand sent to the *** decoding,decoding results are encapsulated into hard ACKsandsent to the sender. There are two contributionsin the proposed scheme： 1. Empl layer calculation instead layer statistics to estimate oying physical of application the packet loss probability of space channel, which can improvethe accuracy and practicality. 2. A cascade overhead-failure probability relationship between the sender and the receiver has been analyzed to help determine the exact numberof packetsneeded byfountain *** show that for space communications,compared with the existing space transport protocols, fountain codes based transport protoeolwith the proposed schemecan not only ensure transmission reliability, but also greatly improvelink utilization.

关键词： fountain code feedback spacecommunication packet loss probabilityestimation transport protocol

Water in peridotite xenoliths from South china

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science china Earth sciences 2011年第10期54卷 1511-1522页

作者： WANG Rong 1,2.3 & ZHANG BaoMin 3 1 Faculty of Land Resource Engineering, Kunming University of science and technology, Kunming 650093,{2. 2.State Key laboratory for Mineral Deposits Research, Nanjing University, Nanjing 2.0093,{2. 3 Faculty of Earth science,{2. University of Geosciences, Wuhan 430074,{2. 1. Faculty of Land Resource Engineering Kunming University of Science and Technology Kunming 650093 China2. State Key Laboratory for Mineral Deposits Research Nanjing University Nanjing 210093 China3. Faculty of Earth Science China University of Geosciences Wuhan 430074 China

The water contents of nominally anhydrous clinopyroxene （cpx）, orthopyroxene （opx） and olivine （ol） in peridotite xenoliths hosted by Cenozoic basalts from Yingfengling, Zhangchouchun, Fujitian and Lindi, South china, were measured by Micro- FTIR. All cpx and opx grains contained a certain amount of water, which was indicated by the presence of hydroxyls in the crystal structure. The water contents （H2., ppm） of cpx and opx from peridotite xenoliths of the study areas were 2.3-981, 183-752. 73-586 and 51-42. ppm, and 82.471, 74-571, 53-170 and 9-135 ppm, respectively. No prominent OH absorption bands were detected for any ol grains, indicating that the water contents were below the detection limit （approximately 2.ppm）. The entire rock contents recalculated according to mineral volume proportions were 49-163, 48-168, 2.-111 and 8-40 ppm, respectively. Combined with previously reported data describing the water contents of peridotite xenoliths worldwide, the results presented here suggest that water distribution in the continental lithospheric mantle is spatially heterogeneous at a global scale. The lithospheric mantle of South china is much richer in water than that of the North china Craton, and is close to that typical of off-craton localities, such as the Basin and Range Province, and Massif Central.

关键词： FTIR water peridotite xenoliths South china

Final Temperature Prediction Model of Molten Steel in RH-TOP Refining Process for IF Steel Production

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Journal of Iron and Steel Research International 2012年第3期19卷 1-5页

作者： WANG Yu-nan1, BAO Yan-ping1, CUI Heng2. CHEN Bin3, JI Chen-xi3 (1. State Key laboratory of Advanced Metallurgy, University of science and {2. Beijing, Beijing 100083, china 2. Engineering Research Institute, University of science and {2. Beijing, Beijing 100083, china 3. Shougang Research Institute of {2., Beijing 100041, china) [a] State Key laboratory of Advanced Metallurgy University of Science and Technology Beijing Beijing 100083 China [b] Engineering Research Institute University of Science and Technology Beijing Beijing 100083 China [c] Shougang Research Institute of technology Beijing 100041 China

In order to precisely control the final temperature of molten steel in RH （Ruhrstahl Heraeus）-TOP blowing refining, the final temperature prediction models of molten steel in RH-TOP blowing refining process for Interstitial Free （IF） steel production were established under the condition of oxygen blowing and non-oxygen blowing respec- tively. The results show that the beginning molten steel temperature of refining and the amount of added scrap were influential factors, the baking temperature in vacuum chamber was a factor that had small influence. When the model was operated, the hitting probability was above 95%（under the condition of both oxygen blowing and non-oxygen blo- wing） of prediction deviation ±10℃. The accuracy is analyzed.

关键词： RH-TOP molten steel temperature prediction model

Characterization of plastic flow in two Zr-based bulk metallic glasses

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science china(Technological sciences) 2006年第4期49卷 414-424页

作者： XING Dongmei1,2. ZHANG Taihua1, LI Weihuo3 & WEI Bingchen3 1. State Key laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sci- ences, Beijing 100080, china 2. College of Physics and Electronic {2. science, Tianjin Normal University, Tianjin 300074, china 3. national Microgravity laboratory, Institute of Mechanics, Chinese Academy of sciences, Beijing 100080, china 1. State Key laboratory of Nonlinear Mechanics (LNM) Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China 2. College of Physics and Electronic information science Tianjin Normal University Tianjin 300074 China 3. national Microgravity laboratory Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

Plastic deformation behaviors of Zr65Al10Ni10Cu15 and Zr52.5Al10Ni10Cu15Be12.5 bulk metallic glasses (BMGs) are studied by using the depth-sensing nanoindentation, microindentation and uniaxial compression. The Be-containing BMG exhibits a signifi- cantly improved overall plastic strain compared with the Be-free alloy during compressive tests. Both BMGs show a loading-rate-dependent serrated flow during nanoindentation measurements, but the Be-containing alloy exhibits a much lower critical loading rate for the disappearance of the serration than the Be-free BMG. The shear band patterns de- veloped during plastic deformation are investigated by microindentation technique, wherein much higher shear band density is found in the Be-containing alloy than in the Be-free alloy, indicating an easier nucleation of shear bands in the former BMG. The dif- ference in the plastic deformation behavior of the two BMGs can be explained by a free volume model.

关键词： Bulk metallic glass, plastic deformation, shear band, nanoindentation.

Fuzzy dynamic characteristic model based attitude control of hypersonic vehicle in gliding phase

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science china({2. sciences) 2011年第3期54卷 448-459页

作者： LUO Xiong 1,2.& LI Jiang 1 1 Department of Computer science and technology, Key {2. of Advanced Control of Iron and Steel Process (Ministry of Education), University of science and technology Beijing, Beijing 100083, china 2.national {2. of Space Intelligent Control, Beijing 100190, china 1. Department of Computer science and technology Key Laboratory of Advanced Control of Iron and Steel Process (Ministry of Education) University of Science and Technology Beijing Beijing 100083 China2. National Laboratory of Space Intelligent Control Beijing 100190 China

The intelligent autonomous control of hypersonic vehicles has aroused great interest from the field of spacecraft. To solve the problem of longitudinal attitude control of hypersonic vehicle in gliding phase, a new intelligent controller is proposed in this paper. This new controller is based on the fuzzy dynamic characteristic modeling method. The fuzzy logic is introduced into the characteristic modeling by dividing the whole restriction range into several subspaces. Simulations show that this modification greatly improves the performance of the original method. With the same whole restriction range the fuzzy dynamic characteristic modeling decreases the time of convergence, and at the same time makes the attitude angle tracing more precise and robust. Since the sub-model is a characteristic model that has stronger adaptiveness than a fixed local model, the number of fuzzy rules is greatly reduced. Our model sharply reduces the complexity in constructing a fuzzy dynamic model. Finally, simulation results are given to show the effectiveness of the proposed approach in dealing with the attitude control problem of hypersonic vehicle in gliding phase.

关键词： hypersonic vehicle gliding attitude control fuzzy dynamic characteristic modeling