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| 1 | Optimization of the head shape of the CRH3 high speed train显示文摘Aiming at optimizing the head shape of the CRH3 high speed train, an efficient optimization approach is proposed. The CFD analysis by solving Navier-Stokes equations is coupled with optimization calculation based on the multi-objective genetic algorithm, meanwhile the arbitrary shape deformation technique (ASD) is also introduced into the design flow, which greatly shortens the time consumption for geometry regeneration and flow field remeshing. As a result, the efficiency of the optimization calculation is highly improved. Statistical analysis is done to the designs in the design space, and the correlation between the design variables and the objective is studied to find out the key variables that most affect the objective. Response surface analysis is also performed to get the nonlinear relationship between the key design variables and the objective with the Kriging algorithm. Finally, after the optimization, an aerodynamic performance comparison between the optimal shape and the original shape reveals that the original shape of CRH3 high speed train owns a very stable aerodynamic performance and can be trustingly used in industry. | SUN ZhenXu1, SONG JingJing1 & AN YiRan1 College of Engineering, State Key Laboratory for Turbulence and Complex Systems, Peking University, Beijing 100871, China | 2010 | Science China(Technological Sciences)2010，53，12： | 35 |
| 2 | Evolutionary decision-makings for the dynamic weapon-target assignment problem显示文摘The dynamic weapon-target assignment (DWTA) problem is an important issue in the field of military command and control. An asset-based DWTA optimization model was proposed with four kinds of constraints considered, including capability constraints, strategy constraints, resource constraints and engagement feasibility constraints. A general 'virtual' representation of decisions was presented to facilitate the generation of feasible decisions. The representation is in essence the permutation of all assignment pairs. A construction procedure converts the permutations into real feasible decisions. In order to solve this problem, three evolutionary decision-making algorithms, including a genetic algorithm and two memetic algorithms, were developed. Experimental results show that the memetic algorithm based on greedy local search can generate obviously better DWTA decisions, especially for large-scale problems, than the genetic algorithm and the memetic algorithm based on steepest local search. | CHEN Jie1,2, XIN Bin1,2, PENG ZhiHong1,2, DOU LiHua1,2 & ZHANG Juan1,2 1 School of Automation, Beijing Institute of Technology, Beijing 100081, China 2 Key Laboratory of Complex System Intelligent Control and Decision, Ministry of Education, Beijing 100081, China | 2009 | Science in China(Series F)2009，52，11： | 19 |
| 3 | Intermediate processes and critical phenomena: Theory, method and progress of fractional operators and their applications to modern mechanics显示文摘From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made. | XU Mingyu1 & TAN Wenchang2 1. Institute of Applied Mathematics, School of Math & System Science, Shandong University, Jinan 250100, China 2. State Key Laboratory of Turbulence and Complex Systems & Department of Mechanics and Engineering Science, Peking University, Beijing 100871, China | 2006 | Science China(Physics,Mechanics & Astronomy)2006，49，3： | 15 |
| 4 | 低压羰基合成丁辛醇工艺技术评析显示文摘低压羰基合成丁辛醇的主要方法有气相法和液相法,目前又开发了第四代低压羰基合成和新催化剂技术。分析对比气相法和液相法的各项技术指标,并与大庆石油化工总厂1996年技术指标进行对比,建议新建装置和改扩建装置采用液相法。 | Zhang Jing (Information and File Department of Daqing Petrochemical Complex , Daqing 163714 ) | 1998 | 黑龙江石油化工1998，9，1： | 15 |
| 5 | Structural ensemble dynamics based closure model for wall-bounded turbulent flow显示文摘Wall-bounded turbulent flow involves the developmentof multi-scale turbulent eddies, as well as a sharplyvarying boundary layer. Its theoretical descriptions are yetphenomenological. We present here a new framework calledstructural ensemble dynamics (SED), which aims at usingsystematically all relevant statistical properties of turbulentstructures for a quantitative description of ensemble means.A new set of closure equations based on the SED approachfor a turbulent channel flow is presented. SED order functionsare defined, and numerically determined from data ofdirect numerical simulations (DNS). Computational resultsshow that the new closure model reproduces accurately thesolution of the original Navier-Stokes simulation, includingthe mean velocity profile, the kinetic energy of the stream-wisevelocity component, and every term in the energy budgetequation. It is suggested that the SED-based studies of turbulentstructure builds a bridge between the studies of physicalmechanisms of turbulence and the development of accuratemodel equations for engineering predictions. | Zhen-Su She Ning Hu You Wu State Key Laboratory for Turbulence and Complex Systems and Dept Mechanical and Aerospace Engineering,College of Engineering, Peking University,100871 Beijing, China | 2009 | Acta Mechanica Sinica2009，25，5： | 11 |
| 6 | Compactness of the commutators of parabolic singular integrals显示文摘In this paper,the authors prove that the commutator [b,T] of the parabolic singular integrals is a compact operator on Lp(Rn)(1 < p < ∞) if and only if b ∈ VMO(Rn,ρ).The result is substantial improvement and extension of some known results. | CHEN YanPing1 & DING Yong2,3 1Department of Mathematics and Mechanics,University of Science and Technology Beijing,Beijing 100083,China 2School of Mathematical Science,Beijing Normal University,Beijing 100875,China 3Laboratory of Mathematics and Complex Systems (BNU),Ministry of Education of China,Beijing 100875,China | 2010 | Science China Mathematics2010，53，10： | 7 |
| 7 | A marsupial robotic fish team: Design, motion and cooperation显示文摘A bio-inspired marsupial robotic fish system composed of heterogeneous robotic fish is proposed in this paper. A miniature robotic fish, as the daughter robotic fish, can adapt to some narrow space, while the mother robotic fish, with a cabin to transport the daughter, possesses a powerful movement ability to improve the mobility and endurance of the team. The structures for mimicking bio-motion and the method for fishlike-motion are presented. A typical task of daughter-mother following is given to show the cooperation of the team. A motion model of free swimming is built based on the Lagrangian function, and the coupled dynamic and kinematic functions are calculated based on the relation between the generalized force and fluid force. Then, a neural network is trained through the data generated from this model to get a predictive yaw controller, which can control the orientation by a different offset of each link. The daughter robotic fish adopts a dynamic light source tracking approach to follow the mother, and a heterogeneous communication-based finite state machine is presented for task modeling. Experiments are carried out to verify the system. | ZHOU Chao*, CAO ZhiQiang, WANG Shuo & TAN Min Laboratory of Complex Systems and Intelligence Science, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China | 2010 | Science China(Technological Sciences)2010，53，11： | 6 |
| 8 | Solid State Reaction Yielding a Mineral Utilizing Silica Obtained from an Agricultural Waste显示文摘Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to produce it through solid state reaction from 900℃ to 1300℃. The conducted reaction was monitored by XRD step by step. Amount of Wollastonite formed at every temperature was also studied to some extent. Analyses of the obtained data indicated that the target mineral formation was quite effective and almost proportional to a rise in temperature up to 1200℃. The results from both, XRD and chemical analysis were found in fair agreement with one | M.S.Nizami M.K.Farooq K.Hussain and M.Z.Iqbal(PCSIR Laboratories Complex, Lahore, Pakistan) | 1999 | Journal of Materials Science & Technology1999，15，3： | 5 |
| 9 | Studies on wind environment around high buildings in urban areas显示文摘High buildings or architectural complex in urban areas remarkably distort the urban surface wind fields. As the air flow approaches,local strong wind may appear around the buildings. The strong wind makes the pedestrians on sidewalks, entrances and terrace very uncomfortable and causes the pedestrian level wind environment problem. In this studies, hot-wire wind measurement, wind scouring in wind tunnel and numerical computation were carried out to evaluate the wind environment of tall buildings in the prevailing flow conditions in Beijing areas. The results obtained by three techniques were compared and mutually verified. The conclusions drawn from three approaches agree with each other. Also the advantages and limitations of each method were analyzed. It is suggested that the combination of different techniques may produce better assessment of wind environment around high buildings. | LIU Huizhi, JIANG Yujun, LIANG Bin, ZHU Fengrong, ZHANG Boyin & SANG Jianguo LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 1000871, China State Key Laboratory of Turbulence and Complex System, Peking University, Beijing 1000871, China | 2005 | Science China Earth Sciences2005，48，z2： | 5 |
| 10 | Universal hierarchical symmetry for turbulence and general multi-scale fluctuation systems显示文摘Scaling is an important measure of multi-scalefluctuation systems. Turbulence as the most remarkablemulti-scale system possesses scaling over a wide range ofscales. She-Leveque (SL) hierarchical symmetry, since itspublication in 1994, has received wide attention. A numberof experimental, numerical and theoretical work havebeen devoted to its verification, extension, and modification.Application to the understanding of magnetohydrodynamicturbulence, motions of cosmic baryon fluids, cosmologicalsupersonic turbulence, natural image, spiral turbulentpatterns, DNA anomalous composition, human heart variabilityare just a few among the most successful examples.A number of modified scaling laws have been derived in theframework of the hierarchical symmetry, and the SL modelparameters are found to reveal both the organizational orderof the whole system and the properties of the most significantfluctuation structures. A partial set of work related tothese studies are reviewed. Particular emphasis is placed onthe nature of the hierarchical symmetry. It is suggested thatthe SL hierarchical symmetry is a new form of the self-organizationprinciple for multi-scale fluctuation systems, andcan be employed as a standard analysis tool in the generalmulti-scale methodology. It is further suggested that the SLhierarchical symmetry implies the existence of a turbulenceensemble. It is speculated that the search for defining theturbulence ensemble might open a new way for deriving statisticalclosure equations for turbulence and other multi-scalefluctuation systems. | Zhen-Su She Zhi-Xiong Zhang State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, 100871 Beijing, China | 2009 | Acta Mechanica Sinica2009，25，3： | 5 |
| 11 | Seam Tracking and Visual Control for Robotic Arc Welding Based on Structured Light Stereovision显示文摘A real-time arc welding robot visual control system based on a local network with a multi-level hierarchy is developed in this paper. It consists of an intelligence and human-machine interface level, a motion planning level, a motion control level and a servo control level. The last three levels form a local real-time open robot controller, which realizes motion planning and motion control of a robot. A camera calibration method based on the relative movement of the end-effector connected to a robot is proposed and a method for tracking weld seam based on the structured light stereovision is provided. Combining the parameters of the cameras and laser plane, three groups of position values in Cartesian space are obtained for each feature point in a stripe projected on the weld seam. The accurate three-dimensional position of the edge points in the weld seam can be calculated from the obtained parameters with an information fusion algorithm. By calculating the weld seam parameter from position and image data, the movement parameters of the robot used for tracking can be determined. A swing welding experiment of type Ⅴgroove weld is successfully conducted, the results of which show that the system has high resolution seam tracking in real-time, and works stably and efficiently. | De Xu, Min Tan, Xiaoguang Zhao, Zhiguo Tu Laboratory of Complex Systems and Intelligence Science, Institute of Automation, Chinese Academy of Sciences, Beijing 100080, PRC | 2004 | International Journal of Automation and computing2004，1，1： | 5 |
| 12 | Asymptotic distributions in the projection pursuit based canonical correlation analysis显示文摘In this paper, associations between two sets of random variables based on the projection pursuit (PP) method are studied. The asymptotic normal distributions of estimators of the PP based canonical correlations and weighting vectors are derived. | JIN Jiao & CUI HengJian Department of Statistics and Financial Mathematics, School of Mathematical Sciences, Beijing Normal University, Laboratory of Mathematics and Complex Systems (Beijing Normal University), Ministry of Education, Beijing 100875, China | 2010 | Science China Mathematics2010，53，2： | 4 |
| 13 | Convergence rates for reversible Markov chains without the assumption of nonnegative definite matrices显示文摘Explicit convergence rates in geometric and strong ergodicity for denumerable discrete time Markov chains with general reversible transition matrices are obtained in terms of the geometric moments or uniform moments of the hitting times to a fixed point.Another way by Lyapunov's drift conditions is also used to derive these convergence rates.As a typical example,the discrete time birth-death process(random walk) is studied and the explicit criteria for geometric ergodicity are presented. | MAO Yong-Hua School of Mathematical Sciences,Beijing Normal University,Laboratory of Mathematics and Complex Systems,Ministry of Education,Beijing 100875,China | 2010 | Science China Mathematics2010，53，8： | 4 |
| 14 | The refined theory of transversely isotropic piezoelectric rectangular beams显示文摘The problem of deducing one-dimensional theory from two-dimensional theory for a transversely isotropic piezoelectric rectangular beam is investigated. Based on the piezoelasticity theory, the refined theory of piezoelectric beams is derived by using the general solution of transversely isotropic piezoelasticity and Lur'e method without ad hoc assumptions. Based on the refined theory of piezoelectric beams, the exact equations for the beams without transverse surface loadings are derived, which consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beams under transverse loadings are derived directly from the refined beam theory. As a special case, the governing differential equations for transversely isotropic elastic beams are obtained from the corresponding equations of piezoelectric beams. To illustrate the application of the beam theory developed, a uniformly loaded and simply supported piezoelectric beam is examined. | GAO Yang1 & WANG Minzhong2 1. College of Science, China Agricultural University, Beijing 100083, China 2. State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engi- neering Science, Peking University, Beijing 100871, China | 2006 | Science China(Physics,Mechanics & Astronomy)2006，49，4： | 3 |
| 15 | Robotic Etiquette:Socially Acceptable Navigation of Service Robots with Human Motion Pattern Learning and Prediction显示文摘Nonverbal and noncontact behaviors play a significant role in allowing service robots to structure their interactions withhumans.In this paper, a novel human-mimic mechanism of robot’s navigational skills was proposed for developing sociallyacceptable robotic etiquette.Based on the sociological and physiological concerns of interpersonal interactions in movement,several criteria in navigation were represented by constraints and incorporated into a unified probabilistic cost grid for safemotion planning and control, followed by an emphasis on the prediction of the human’s movement for adjusting the robot’spre-collision navigational strategy.The human motion prediction utilizes a clustering-based algorithm for modeling humans’indoor motion patterns as well as the combination of the long-term and short-term tendency prediction that takes into accountthe uncertainties of both velocity and heading direction.Both simulation and real-world experiments verified the effectivenessand reliability of the method to ensure human’s safety and comfort in navigation.A statistical user trials study was also given tovalidate the users’favorable views of the human-friendly navigational behavior. | Kun Qian,Xudong Ma,Xianzhong Dai,Fang Fang Key Lab of Measurement and Control of Complex Systems of Engineering (Ministry of Education,China), Southeast University,Nanjing 210096,P.R.China | 2010 | Journal of Bionic Engineering2010，7，2： | 3 |
| 16 | Hierarchical structures in climate and atmospheric turbulence显示文摘The climatic time series encompass many time scales, forming multi-scale climatic variations and hierarchies. The periods and magnitudes of cooling or warming, especially for extreme climatic events, vary with the time scales. On the other hand, high-frequency atmospheric turbulent motions, which are certainly related to the climatic changes, are also typical multi-scale phenomena. In this paper, certain properties of the fluctuations are examined that are invariant with the change of the time scales. Specifically, the existence of a statistical similarity law is demonstrated in climatic time series and in atmospheric turbulent motions. This is the hierarchical similarity law. Further analyses show that the hierarchical similarity law is a general property of multi-scale fluctuation systems. Therefore, the study on the hierarchical similarity law is important for understanding the inherent universal physical mechanism of complex systems in the atmospheric motions. | SHE Zhensu, FU Zuntao, CHEN Jiong, LIANG Shuang and LIU Shida(1. State Key Laboratory for Studies of Turbulence and Complex Systems, Department of Mechanics and Engineering Sciences, Peking University, Beijing 100871, China 2. School of Physics, Peking University, Beijing 100871, China 3. LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China) | 2002 | Progress in Natural Science:Materials International2002，12，10： | 3 |
| 17 | DISCRIMINANT ANALYSIS BASED ON STATISTICAL DEPTH显示文摘In the past two decades,many statistical depth functions seemed as powerful exploratoryand inferential tools for multivariate data analysis have been presented.In this paper,a new depthfunction family that meets four properties mentioned in Zuo and Serfling(2000)is proposed.Then aclassification rule based on the depth function family is proposed.The classification parameter b couldbe modified according to the type-Ⅰ error α,and the estimator of b has the consistency and achievesthe convergence rate n^(-1/2).With the help of the proper selection for depth family parameter c,theapproach for discriminant analysis could minimize the type-Ⅱ error β.A simulation study and a realdata example compare the performance of the different discriminant methods. | Jiao JIN·Hengjian CUI School of Mathematical Sciences,Key Laboratory of Mathematics and Complex Systems,Ministry of Education, Beijing Normal University,Beijing 100875,China. | 2010 | Journal of Systems Science & Complexity2010，23，2： | 3 |
| 18 | AN EXPERT SYSTEM FOR COMPUTER AIDED ALLOY STEEL DESIGN—ASPRES显示文摘An alloy steel pattern recognition expert system,ASPRES,has been established for thepurpose of computer aided optimal design of alloy steel in compositions and process pa-rameters,Pattern recognition techniques are used to abstract inner relationship betweenmechanical properties and process variables.The ASPRES uses 2-dimensional graph asvisual knowledge to represent domain expertise of specific object.Forward and back-ward chaining can be utilized by researcher in predicting sample performances or givinghelpful suggestions about the chemical compositions and process parameters accordingto desired properties. | CHEN Yu CHEN Nianyi Shanghai institute of Metallurgy,Academia Sinica,Shanghai,China PENG Ping KONG Bingyu Iron and Steel Research Institute,Shanghai Baoshan Iron and Steel Complex,Shanghai,China professor,Shanghai Institute of Metallurgy,Academia Sinica,Shanghai 200050,China | 1993 | Acta Metallurgica Sinica(English Letters)1993，6，8： | 2 |
| 19 | The Cosmic Dust in Suzhou Granite:Ablated Products of a Cometary Explosion | Hu Zhong-wei,Wang Er-kang,Wan Yu-qiuDepartement of Astronomy,Nanjing University,Nanjing 210093,China Department of Earth Sdence,Nanjing University,Nanjing 210093,China Cosmic dust has been collected in large number from deap-sea sediments,Greenland ice deposits,the stratosphere and space,of cosmic dust,some are the unmelted micrometeorite,and most are the ablated products of me-teoroids in the atmosphere.Cosmic dusts were recovered from two sites of the 1908 Tunguska explosion and the 1965 Revelstoks explosion Since 1987,a large number of microspherules have been extracted from Suzhou granite of China Their suface and section structures,mineral and chemical composition show that these microspherules are of the ablated cosmic dust.The microspherules occurred in the inner contact complex intrusion.It suggests that the microspherules may be products of the same event and were aggergated in some strata and then captured by the emplacement of granitic magma.Although the microspherules are similare to other ablated cosmic dusts,there are some diferences.Our calculated results of cometary motion through the atmosphere and explosion show that the microspherules may be the ablated dust of a comet with mass above 1015g at its explosion near the ground. | 1996 | 紫金山天文台台刊1996，15，3： | 2 |
| 20 | Chemical Kinetic Aspects of Solid State Reaction Producing Wollastonite from Rice Husk Silica and Limestone显示文摘An industrial mineral wollastonite (CaSiO3) was produced under solid state conditions from rice husk silica and limestone. Reaction was carried out at 900’C to 1300’C for 1 h. The product batches were subjected to XRD and chemical analysis techniques specific for wollastonite. Mole fractions of different product batches were calculated on the basis of accumulated data to study the kinetics. Specific rate constants and reaction rate were also found out. Various probable models of mechanism for reaction were considered and testified with the laid down criterion for suggesting the suitable one. The resulting data were treated with Arrhenius equation as well and activation energy was calculated--therefrom. In addition to finding it’s value from the slope of Arrhenius curve, an alternate method was also applied for this purpose. Both of the values were observed to be comparable. The activation energy required for performed reaction was found to be almost one third of that reported for synthesizing CaSiO3 by using quartz. This referred to the economical preparation of wollastonite by using rice husk as a source of silica instead of quartz. | M.S.Nizami PCSIR Laboratories Complex, Lahors, Pakistan M.Z.Iqbal Punjab University, Institute of Chemistry, Lahors, Pakistan | 2001 | Journal of Materials Science & Technology2001，17，2： | 2 |
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