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    题名 作者 年代 出处 被引量
1Fuzzy interface treatment in Eulerian method显示文摘In this paper, we incorporate fuzzy mathematics approach into the Eulerian method to simulate three dimensional multi-material interfaces. In particular, we propose a fuzzy interface treatment for describing interfaces, designing transport plans, and computing transport quantities. Using a set of three-dimensional inviscid isothermal elastic-plastic hydrodynamic equations, we simulate shaped charge jet in different filled dynamite structures. Strain and stress have been under consideration in simulations. Numerical results demonstrate that the fuzzy interface treatment is correct and efficient for three-dimensional multi-material problems.NING Jianguo1 & CHEN Longwei1,2 1. National Key Laboratory of Protection and Control of Explosive Disaster, Beijing Institute of Technology, Beijing 100081, China 2. The Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China Correspondence should be addressed to Ning Jianguo 2004Science China(Technological Sciences)2004,47,5:40
2Simulation of energy and water balance in Soil-Vegetation-Atmosphere Transfer system in the mountain area of Heihe River Basin at Hexi Corridor of northwest China显示文摘In the mountain area of inland Heihe River Basin at Hexi Corridor of northwest China during the vegetation growing season from May to September, the Simultaneous Heat and Water (SHAW) model of Soil-Vegetation-Atmosphere Transfer (SVAT) system is applied to simulating and studying energy and water balance of the soil-residue-plant canopy layers in the Picea crassifolia forest and the grassland by the forest at the shaded slope and the grassland at the sun-facing slope. The simulation of energy balance indicates that net radiation of the grass- land at the sun-facing slope is more than that of the Picea crassifolia forest and the grassland by the forest at the shaded slope. The energy outgoing components are the first latent heat and next sensible heat from the grassland both at the shaded slope and the sun-facing slope, but those at the former are less. The energy outgoing components are the first sensible heat and next latent heat from the Picea crassifolia forest. The composition and distribution of energy in the soil-residue-plant canopy layers in the Picea crassifolia forest and the grassland by the forest at the shaded slope make the soil layer receive less energy, which therefore, especially the forest possesses the energy conditions for soil water conservation. The simulation of water balance indicates that the water loss of the grassland at the sun-facing slope is mainly caused by soil evaporation, while evapotranspiration of the Picea crassifolia forest and the grassland by the forest at the shaded slope is less than that of the grassland at the sun-facing slope. Half of the evapotranspiration of the Picea crassifolia forest and the grassland by the forest at the shaded slope is consumed by transpiration. After precipitation, the soil water storage is increased much more for the Picea crassifolia forest and also more for the grassland by the forest at the shaded slope. Therefore the shaded slope vegetation, especially the forest is favorable for soil water storage.KANG Ersi1, CHENG Guodong1, , SONG Kechao1, JIN Bowen1, , LIU Xiande3 2 3 & WANG Jinye3 1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 2. State Key Laboratory of Frozen Soil Engineering, Chinese Academy of Sciences, Lanzhou 730000, China 3. Academy of Water Resources Conservation Forest of Qilian Mountains, Gansu Province, Zhangye 734000, China 2005Science China Earth Sciences2005,48,4:25
3Some characteristics and evolution of the internal soliton in the northern South China Sea显示文摘Based on the observational data of an internal soliton in the northern South China Sea (SCS) on June 14, 1998, the possible source of the internal soliton is analyzed, and some of its characteristic parameters such as phase speed, wave length, etc. are computed. Based on the analyses of the vertical modes of the internal wave, the characteristics of the wave-induced current during the propagation of the internal soliton are studied. A regularized long wave (RLW) equation numerical model considering effects of multi-fac-tors is employed, and the observed environmental parame-ters are used as the initial conditions to simulate the propa-gation and evolution of the internal soliton in the continental shelf of the northern SCS.Cai, SQ Gan, ZJ Long, XM 2002Chinese Science Bulletin2002,47,1:23
4Integration of principal components analysis and cellular automata for spatial decisionmaking and urban simulation显示文摘This paper discusses the issues about the correlation of spatial variables during spatial decisionmaking using multicriteria evaluation (MCE) and cellular automata (CA). The correlation of spatial variables can cause the malfunction of MCE. In urban simulation, spatial factors often exhibit a high degree of correlation which is considered as an undesirable property for MCE. This study uses principal components analysis (PCA) to remove data redundancy among a large set of spatial variables and determine 'ideal points' for land development. PCA is integrated with cellular automata and geographical information systems (GIS) for the simulation of idealized urban forms for planning purposes.黎夏 叶嘉安 2002Science China Earth Sciences2002,45,6:12
5Preliminary study on assessment of nutrient transport in the Taihu Basin based on SWAT modeling显示文摘With the Taihu Basin as a study area, using the spatially distributed and mechanism-based SWAT model, preliminary simulations of nutrient transport in the Taihu Basin during the period of 1995~2002 has been carried out. The topography, soil, meteorology and land use with industrial point pollution discharge, the loss of agricultural fertilizers, urban sewerage, and livestock drainages were all considered in the boundary conditions of the simulations. The model was calibrated and validated against water quality monitoring data from 2001 to 2002. The results show that the annual total productions of nitrogen (TN) and phosphorus (TP) into Lake Taihu are 40000t and 2000t respectively. Nutrient from the Huxi Region is a major resource for Lake Taihu. The non-point source (surface source) pollution is the main form of catchment sources of nutrients into Lake Taihu,occupied TN 53% and TP 56% respectively. TN and TP nutrients from industrial point pollution discharge are 30% and 16%, and sewerage in both forms of point source and non-point source are TN 31% and TP 47%. Both the loss of agricultural fertilizers and livestock drainages from the catchment should be paid more attention as an important nutrient source. The results also show that SWAT is an effective model for the simulation of temporally and spatially nutrient changes and for the assessment of the trends in a catchment scale.LAI Geying, YU Ge & GUI Feng Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China The Graduate School of the Chinese Academy of Sciences, Beijing 100039, China Key Lab of Poyang Lake Ecological Environment and Resource Development, Jiangxi Normal University, Nanchang 330027, China 2006Science China Earth Sciences2006,49,z1:11
6Relative efficiency of marker assisted selection when marker and QTL are incom-pletely linked显示文摘The relative superiority in selection response of two basic marker-assisted selection strategies, marker-assisted BLUP (MBLUP) and two-stage selection, in comparison to standard BLUP was investigated using stochastic simulation of a closed nucleus herd. In marker-assisted BLUP the marker information and the phenotypic information were utilized simultaneously for selecting parental animals, whereas in two-stage selection they were utilized separately in two stages. Different heritabilities and QTL sizes were considered in the simulation. The QTL was assumed to be referred only via flanking markers, which were incompletely linked to the QTL. It was shown that both MBLUP and two-stage selection increased the QTL response but decreased the polygenic response. When the heritability was low or the QTL effect was large MBLUP was superior to standard BLUP by up to 5% with respect to total genetic response. While the two-stage selection did not show any superiority although it gave extremely large increase inLiu Huiying Zhang Qin Zhang Yuan 2001Chinese Science Bulletin2001,46,24:11
7The Numerical Simulation of the Climatic Change Caused by CO_2 Doubling显示文摘The IAP two-level atmospheric general circulation model was coupled to a 60-m-deep mixed layer ocean model and a zero-layer thermodynamic model to simulate the climatic effects induced by a doubling of CO2 concentration in the atmosphere.The global surface temperature is 1.75℃ when CO2 is doubled. This value is lower than most of other results in the world, such as those of GFDL, NCAR, UKMO, GISS and OSU models.There are large regional and seasonal differences in the climatic change. Great warming is found in the Northern Hemisphere’s high-latitude region anti the Antarctica; and the warming in land areas is greater than in ocean areas, while the precipitation increases in high latitudes and tropical regions but decreases in subtropical regions. In both hemispheres, the warming is greater in winter than in other seasons. As for the changes in China, we find that the precipitation in southwestern and northern China greatly decreases in summer but increases in winter.王会军 曾庆存 张学洪 1993Science China Chemistry1993,36,4:11
8Direct numerical simulation of a supersonic turbulent boundary layer on a flat plate and its analysis显示文摘Temporal mode direct numerical simulation (DNS) has been done for a supersonic turbulent boundary layer on a flat plate with Mach number 4.5. It was found that the mean flow profile, the normal-wise distribution of turbulent Mach number and the root mean square (RMS) of the fluctuations of various variables, as well as the Reynolds stresses, bore similarity in nature, when the turbulence reached a fully developed state. But the compressibility effect was strong and must be considered. The strong Reynolds analogy (SRA) and the Morkovin hypothesis were no longer valid. From the end of transition to the fully developed state of turbulence, it was in the transient period, for which the similarity did not hold.HUANG Zhangfeng1, ZHOU Heng1,2 & LUO Jisheng1,2 1. Department of Mechanics, Tianjin University, Tianjin 300072, China 2. Liu-Hui Center of Applied Mathematics, Nankai University and Tianjin University, Tianjin 300072, China 2005Science China(Physics,Mechanics & Astronomy)2005,48,5:9
9Formation and evolution mechanisms of large-clusters during rapid solidification process of liquid metal Al显示文摘A molecular dynamics simulation study has been performed for the formation and evolution characteristics of nano-clusters in a large-scale system consisting of 400000 atoms of liquid metal Al. The center-atom method combined with pair-bond analysis technique and cluster-type index method (CTIM) has been applied here to describe the structural configurations of various basic clusters. It is demonstrated that both the 1551 bond-type and the icosahedral cluster (12 0 12 0) constructed by 1551 bond-types are dominant among all the bond-types and cluster-types, respectively, in the system and play a critical role in the microstructure transitions of liquid metal Al. The nano-clusters (containing up to 150 atoms) are formed by the combination of some middle and small clusters with distinctly different sizes, through mutual competition by unceasing annex and evolution in a seesaw manner (in turn of obtaining and losing),which do not occur as the multi-shell structures accumulated with an atom as the center and the surrounding atoms are arranged according to a certain rule. This is the essential distinction of nano-cluster in liquid metal from those obtained by gaseous deposition, ionic spray methods, and so on. Though the nano-clusters differ from each other in shape and size, all of them possess protruding corners that could become the starting points of various dendrite structures in the solidification processes of liquid metals.LIU Rangsu, DONG Kejun, LIU Fengxiang, ZHENG Caixing, LIU Hairong & LI Jiyong Department of Applied Physics, Hunan University, Changsha 410082, China College of Materials Science and Engineering, Hunan University, Changsha 410082, China College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China 2005Science China(Physics,Mechanics & Astronomy)2005,48,1:7
10A new Monte Carlo simulation of three-dimensional microstructures and their evolution in polycrystalline显示文摘A new Monte Carlo simulation method for studying three-dimensional microstructures as well as their evolution in polycrystalline materials has been set up. The algorithm is simple and flexible to apply. With the present method, kinetics of three-dimensional grain growth is accurately reflected and the simulation efficiency is greatly improved. The simulation can not only be used reliably to analyze quantitatively the microstructures and their evolution, but also be used conveniently to observe microstructures as well as their evolution on the horizontal section and the sections at any angle to the horizontal plane, to measure the characteristic parameters in three dimensions and cross-sections, together with their relationships between the two systems, and to many other aspects.Xiaoyan Song Guoquan Liu Nanju Gu 1999Chinese Science Bulletin1999,44,15:6
11Safety analysis of wheel brake system based on STAMP/STPA and Monte Carlo simulation显示文摘The wheel brake system safety is a complex problem which refers to its technical state, operating environment, human factors, etc., in aircraft landing taxiing process. Usually, professors consider system safety with traditional probability techniques based on the linear chain of events. However, it could not comprehensively analyze system safety problems, especially in operating environment, interaction of subsystems, and human factors. Thus,we consider system safety as a control problem based on the system-theoretic accident model, the processes(STAMP) model and the system theoretic process analysis(STPA) technique to compensate the deficiency of traditional techniques. Meanwhile,system safety simulation is considered as system control simulation, and Monte Carlo methods are used which consider the range of uncertain parameters and operation deviation to quantitatively study system safety influence factors in control simulation. Firstly,we construct the STAMP model and STPA feedback control loop of the wheel brake system based on the system functional requirement. Then four unsafe control actions are identified, and causes of them are analyzed. Finally, we construct the Monte Carlo simulation model to analyze different scenarios under disturbance. The results provide a basis for choosing corresponding process model variables in constructing the context table and show that appropriate brake strategies could prevent hazards in aircraft landing taxiing.HU Jianbo ZHENG Lei XU Shukui 2018Journal of Systems Engineering and Electronics2018,29,6:6
12New Discoveries in Study on Hydrocarbons From Thermal Degradation of Heterotrophically Yellowing Algae显示文摘Green autotrophic alga Chlorella protothecoides contains a very small quantity of hydrocarbons. Heterotrophic culture of this alga results in the cells yellowing, chlorophyll disappearing, protein decreasing and lipid increasing remarkably. The quantities of hydrocarbons from them directly and from the thermal degradation of the cells at or below 200℃ are very low. These hydrocarbons are characterized by predominance of high molecular weight normal alkanes with maximum at C23-C25. When these heterotrophi-cally yellowing cells are thermally degraded at 300℃ , the aliphatic hydrocarbons increase greatly, 32 times that of the green autotrophic ones at the same temperature. Meanwhile, the low molecular weight normal alkanes with C17 as the peak become predominant instead of the original ones of high molecular weight. The actual potential of microplanktonic algae in producing hydrocarbons should be much greater than what people have recognized before.吴庆余 殷实 盛国英 傅家谟 1994Science China Chemistry1994,37,3:6
13Studies 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 2005Science China Earth Sciences2005,48,z2:5
14A dynamic model with substructures for contact-impact analysis of flexible multibody systems显示文摘Using a substructure synthesis method this paper studies the longitudinal compressive impact of a flexible bar with a rigid body. The crucial variable affecting the validity of the method is derived theoretically. By computational simulation tests, excellent agreement has been found be-tween the solution of this model and the exact solution when the variable is chosen suitably. Con-sidering both the computational efficiency and the accuracy of solutions obtained on the model in different engineering problems, several optimum values of the variable are suggested.郭安萍 洪嘉振 杨辉 2003Science China(Technological Sciences)2003,46,1:5
15Numerical analysis of the source-sink alternation of composite global warming potential of the paddy ecosystem in the Yangtze Delta显示文摘By coupling the biogeochemical model with plant ecological model, a model was established to reveal the principle of the composite global warming potential transformation in the paddy ecosystem. Validation of the model with the observed data indicated that the model can simulate both the crop growth processes and emissions of CH4 and N2O accurately. Some nu-merical analyses were made to identify the impacts of different fertilizer application on assimilation of CO2 and emissions of CH4 and N2O, and the transformation principle of the composite global warming potential. Based on the results of the numerical analysis, the source-sink alternation of composite global warming potential in the paddy ecosystem was discovered, and some new con-ceptions of fertilizer index such as maximum-sink fertilizer, zero-emission fertilizer are put forward in this paper. The fertilizer scheme for Yangtze Delta was proposed to provide the important scien-tific basis for a sustainable agriculture in this region.刘建栋 周秀骥 于强 2003Science China Earth Sciences2003,46,4:5
16The finite difference method for the three-dimensional nonlinear coupled system of dynamics of fluids in porous media显示文摘For the three-dimensional coupled system of multilayer dynamics of fluids in porous media, the second-order upwind finite difference fractional steps schemes applicable to parallel arithmetic are put forward. Some techniques, such as calculus of variations, energy method,multiplicative commutation rule of difference operators, decomposition of high order difference operators and prior estimates are adopted. Optimal order estimates in l2 norm are derived to determine the error in the second-order approximate solution. These methods have already been applied to the numerical simulation of migration-accumulation of oil resources.YUAN Yirang 2006Science China Mathematics2006,49,2:5
17Film condensation heat transfer on a vertical porous-layer coated plate显示文摘Film condensation on a vertical porous coated plate is investigated numerically for a porous/fluid composite system based on the dispersion effect in the porous coating. The mathematical model improves the conventional matching conditions by considering the stress force at the porous coating interface. The numerical results show the effects of the porous coating thickness, the effective thermal conductivity and the permeability on condensate film thickness and local Nusselt number. The predicted average Nusselt number has similar tendencies to experimental results reported in literature, such that using a thin porous coating would be a viable alternative for enhancing the condensation heat transfer.马学虎 王补宣 1998Science China(Technological Sciences)1998,41,2:4
18A New Method with High Confidence for Validation of Computer Simulation Models of Flight Systems显示文摘Computer simulation models may by used to gain further information about missile performance variability. Model validation is an important aspect of the test program for a missile system. Validation provides a basis for confidence in the model’s results and is a necessary step if the model is to be used to draw inference about the behavior of the real missile. This paper is a review of methods useful for validation of computer simulation models of missile systems and provides a new method with high degree of confidence for validation of computer simulation models of missile systems. Some examples of the use of the new method in validating computer simulation models are given.Zhou XianminShanghai Research & Development Centre, 412 Guil in Road, Shanghai 200233, P.R.China 1993Journal of Systems Engineering and Electronics1993,4,4:4
19A numerical simulation of nonlinear propagation of gravity wave packet in three-dimension compressible atmosphere显示文摘By using FICE scheme, a numerical simulation of nonlinear propagation of gravity wave packet in three-dimension compressible atmosphere is presented. The whole nonlinear propagation process of the gravity wave packet is shown; the basic characteristics of nonlinear propagation and the influence of the ambient winds on the propagation are analyzed. The results show that FICE scheme can be extended in three-dimension by which the calculation is steady and kept for a long time; the increase of wave amplitude is faster than the exponential increase according to the linear gravity theory; nonlinear propagation makes the horizontal perturbation velocity increase greatly which can lead to enhancement of the local ambient winds; the propagation path and the propagation velocity of energy are different from the results expected by the linear gravity waves theory, the nonlinearity causes the change in propagation characteristics of gravity wave; the ambient winds alter the propagation path and group velocity of gravity wave.吴少平 易帆 2002Science China(Technological Sciences)2002,45,3:4
20A numerical investigation of the evolution of 2-D disturbances in hypersonic boundary layers and the effect on the flow structure due to the existence of shocklets显示文摘CAO Wei & ZHOU Heng Department of Mechanics,Tianjin University Liu Hui Center of Applied Mathematics,Nankai and Tianjin University,Tianjin 300072,China Correspondence should be addressed to Zhou Heng(email:hzhou 1 @ tju.edu.cn) 2004Science China(Physics,Mechanics & Astronomy)2004,47,2:4
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