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再生资源生态全产业链主体界定、现状及对策——基于“源”“流”“汇”的视角
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作者 王利艳 张秀萍 《生态经济》 北大核心 2024年第1期160-169,共10页
“源—流—汇”生态控制理论能够更好地分析再生资源生态系统的运作状态与过程,论文基于“源”“流”“汇”的研究视角,界定再生资源生态全产业链结构与主体构成,通过多种数据库收集数据与深度访谈调研,研究“源”“流”“汇”三大系统... “源—流—汇”生态控制理论能够更好地分析再生资源生态系统的运作状态与过程,论文基于“源”“流”“汇”的研究视角,界定再生资源生态全产业链结构与主体构成,通过多种数据库收集数据与深度访谈调研,研究“源”“流”“汇”三大系统主体发展现状。研究结果发现:“源”系统由于工业固体废弃物产生量逐年上升及生活垃圾产生量持续增加的压力,造成源头减量短时间内难以实现;“流”系统再生资源的回收规模呈上升趋势,而再生资源的综合利用水平较低,致使再生资源化能力整体薄弱;“汇”系统末端处理压力较大。由此,提出提升公众参与意识、发挥再生资源企业规模优势、加快末端处理的相关配套建设等相应的发展对策,以期为实现“产品—再生资源—再生原料—再生产品”一体化“零废弃”的循环系统提供科学参考。 展开更多
关键词 再生资源生态全产业链 “源”系统 “流”系统 “汇”系统 主体
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Investigation on the Optimizing Range of CombustionChamber Configuration Parameters of DSCS 被引量:1
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作者 李向荣 张国栋 魏熔 《Journal of Beijing Institute of Technology》 EI CAS 1998年第2期147-153,共7页
Aim To obtain an optimizing range of the main configuration parameters of double swirls combustion system (DSCS) Methods To analyze the influence of DS combustion cham-ber configuration parameters on fuel spray and mi... Aim To obtain an optimizing range of the main configuration parameters of double swirls combustion system (DSCS) Methods To analyze the influence of DS combustion cham-ber configuration parameters on fuel spray and mixing by means of the fuel jet developmentperiphery charts obtained by the high speed photography with a modeling test device deve-loped by authors,and to examine it by the tests on a single cylinder diesel engine.Resultsand Conclusion The mixing process can be divided into four phases.The optimizing range of the ration of the inner chamber diameter to the cylinder bore,d2/D,is 0.4-0.7; and the outerchamber diameter,d1 the height of the circular ridge to the piston top face,h1,the radius of outer/inner chamber circle,R1,R2 ,the max depth of outer/inner chamber bowl,H1,H2,etc. are also important 展开更多
关键词 diesel engine double swirls combustion system configuration parameter optimizing range
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Estimating runoff coefficient for quantity assessment of roof rainwater harvesting system 被引量:1
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作者 张炜 李思敏 唐锋兵 《Journal of Southeast University(English Edition)》 EI CAS 2014年第2期220-224,共5页
In order to accurately estimate the runoff coefficient for the quantity assessment of the roof rainwater harvesting system RRHS great differences in the value of event runoff coefficient ψERC were observed by field m... In order to accurately estimate the runoff coefficient for the quantity assessment of the roof rainwater harvesting system RRHS great differences in the value of event runoff coefficient ψERC were observed by field monitoring under different roof types roof slope and material and diverse rainfall distributions rainfall depth and intensity in three years 2010 to 2012 in Handan Hebei China.The results indicate that the distribution of ψERC is more highly correlated with the event rainfall depth than other factors. The relationship between ψERC and the rainfall depth can be well represented by the piecewise linear function.Further based on the daily rainfall data over the period from 1960 to 2008 the value of the annual runoff coefficient ψARC is calculated. Although the total rainfall depth in each year is different ψARC in Handan can be considered as a constant 0.62 approximately. The results can be used for the quantity assessment and performance analysis of the RRHS. 展开更多
关键词 roof rainwater harvesting system event runoff coefficient annual runoff coefficient rainfall depth
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Modeling of container terminal logistics system based on multi-agent
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作者 李斌 李文锋 +1 位作者 张煜 张敏 《Journal of Southeast University(English Edition)》 EI CAS 2007年第S1期146-150,共5页
The similarities and differences between the container terminal logistics system(CTLS)and the Harvard-architecture computer system are compared in terms of organization and architecture.The mapping relation and the mo... The similarities and differences between the container terminal logistics system(CTLS)and the Harvard-architecture computer system are compared in terms of organization and architecture.The mapping relation and the modeling framework of the CTLS are presented based on multi-agent,and the successful algorithms in the computer domain are applied to the modeling framework,such as the dynamic priority and multilevel feedback scheduling algorithm.In addition,a model and simulation on a certain quay at Shanghai harbor is built up on the AnyLogic platform to support the decision-making of terminal on service cost.It validates the feasibility and creditability of the above systematic methodology. 展开更多
关键词 container terminal logistics system Harvard architecture multi-agent system SCHEDULING
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NUMERICAL SIMULATION ON AERODYNAMIC CHARACTERISTICS OF WINDBLAST PROTECTION AT HIGH SPEED 被引量:1
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作者 魏涛 张大林 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2009年第4期268-273,共6页
The computational fluid dynamics (CFD) method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisa... The computational fluid dynamics (CFD) method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisation. The detached-eddy simulation (DES) based on the Spalart-Allmaras one-equation turbulence model is ap- plied to the detached viscous flow simulation behind the seat/occupant, with Mach numbers 0.6 and 1.2 at attack angles between --10 and 30°, and at two sideslip angles of 0 and 15°, respectively. The aerodynamic characteristics of seat/occupants with and without windblast protection devices are calculated in cases of the freestream Mach numbers 0. 8 and 1.6, attack angles from 5 to 30°, and three sideslip angles of 0, --20 and --50°, respectively. Results show that simulation results agree well with experimental data. And the occupant is efficiently protected by windblast protection devices. 展开更多
关键词 computational fluid dynamics seat/occupant systems upwind Osher scheme windblast protectionaerodynamic characteristics
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LOAD FLOW CALCULATION FOR FLEXIBLE AC TRANSMISSION SYSTEMS
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作者 陈礼义 蒲天骄 +3 位作者 李林川 董雷 康熙 陈超英 《Transactions of Tianjin University》 EI CAS 1997年第2期9-13,共5页
In this paper, a synthetic mathematical model of load flow for flexible AC transmission systems (FACTS) with unified power flow controller (UPFC) is presented based on the analysis of basic principle and operation sta... In this paper, a synthetic mathematical model of load flow for flexible AC transmission systems (FACTS) with unified power flow controller (UPFC) is presented based on the analysis of basic principle and operation state of UPFC. The model can use the fast P Q decoupled load flow method. Examples of test systems show that the proposed model and method have good convergence. An effective tool is provided by the load flow computer program to analyze the load flow and initial valve calculation of the dynamic state of FACTS. 展开更多
关键词 FACTS UPFC load flow calculation
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Review of forest ecology studies in China 被引量:3
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作者 王庆礼 邓红兵 +1 位作者 王绍先 李杨 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第3期231-234,252,共4页
As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the ... As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches. 展开更多
关键词 FOREST ECOSYSTEM Forest ecology Structure and function MANAGEMENT HEALTH WATERSHED
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Investigating Jet Appearance in Different Background Lights with High-Speed Frame Photography 被引量:4
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作者 王成 恽寿榕 +1 位作者 黄风雷 张汉萍 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期113-116,共4页
Shaped charge jet formation process is studied under the conditions of different background lights by means of high speed frame photography. In order to shoot true jet appearance, the glass tube in which jet moves is... Shaped charge jet formation process is studied under the conditions of different background lights by means of high speed frame photography. In order to shoot true jet appearance, the glass tube in which jet moves is vacuumized. The experiment results show that observing jet appearance with the double reflecting mirrors system is feasible as long as the vacuum of the glass tube can meet the requirement of experiment. 展开更多
关键词 high speed frame photography double reflecting mirrors system shaped charge JET
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Dynamic Response of IBM3370 Slider in High Density Recording Systems 被引量:1
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作者 范钦满 陈云飞 《Journal of Southeast University(English Edition)》 EI CAS 1999年第2期98-104,共7页
A liquid lubricated head disk system is introduced. Subjected to high shear rate the rheology of the ultra thin film is different from that of the bulk continuum theory. The shear thinning effect is considered in set... A liquid lubricated head disk system is introduced. Subjected to high shear rate the rheology of the ultra thin film is different from that of the bulk continuum theory. The shear thinning effect is considered in setting up the mathematical model of the ultra thin film rheology. The Reynolds equation and the perturbation theory are employed to set up the static pressure distribution model and to deduce the dynamic pressure equation. The static and dynamic equations are solved by finite difference method. Based on the dynamic analysis the dynamic response of the slider is simulated and some valuable results are obtained about the static and dynamic characteristics of the liquid lubricated head disk systems. 展开更多
关键词 dynamic characteristics thin film lubrication head disk system
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Application of water loop variable refrigerant flow air-conditioning system in large-scale buildings in northern China
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作者 孙婷婷 倪龙 +1 位作者 姚杨 马最良 《Journal of Southeast University(English Edition)》 EI CAS 2010年第2期197-200,共4页
A water loop variable refrigerant flow(WLVRF)air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a va... A water loop variable refrigerant flow(WLVRF)air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow(VRF)air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system. 展开更多
关键词 variable refrigerant flow air-conditioning system water loop large-scale building
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Singular Points, Closed Orbits, Stable Manifolds and Unstable Manifolds of Second Order Autonomous Birkhoff Systems 被引量:1
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作者 陈向炜 梅凤翔 《Journal of Beijing Institute of Technology》 EI CAS 1998年第4期330-336,共7页
Aim To study singular points, closed orbits, stable manifolds and unstable manifolds of a second order autonomous Birkhoff system. Methods Qualitative methods of ordinary differential equation were used. Results and ... Aim To study singular points, closed orbits, stable manifolds and unstable manifolds of a second order autonomous Birkhoff system. Methods Qualitative methods of ordinary differential equation were used. Results and Conclusion The criteria for singular points, closed orbits and hyperbolic equilibrium points of a second order autonomous Birkhoff system are given. Moreover the stability of equilibria, stable manifolds and unstable manifolds are obtained. 展开更多
关键词 Birkhoff system singular point closed orbit stable manifold unstable manifold
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DC LOOP-CURRENT DETECTING AND RESTRAINING METHODS FOR PARALLEL INVERTER SYSTEM
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作者 陈良亮 肖岚 严仰光 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2004年第1期1-6,共6页
DC component is contained in inverter output voltage due to many reasons such as the zero-point deviation of operational amplifiers and the differences between power switching transistors′ characteristics. For the pa... DC component is contained in inverter output voltage due to many reasons such as the zero-point deviation of operational amplifiers and the differences between power switching transistors′ characteristics. For the parallel inverter system without output isolation transformers, the difference of DC components of the output voltage can cause large DC loop-current among modular inverters. Aiming at this problem, this paper studies several DC loop-current detecting and restraining methods. By digital adjustment with high precision on the DC components of reference sine wave, the DC components of inverter′s output voltage can be adjusted to restrain DC loop-current. Experimental results prove that the DC loop-current detecting and restraining methods have a good performance. 展开更多
关键词 DC loop-current DETECT digital adjustment parallel inverter
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Virtual Laboratory for Corporations: The Source of Policy
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作者 于跃海 何建敏 《Journal of Southeast University(English Edition)》 EI CAS 2000年第1期95-100,共6页
Many corporations are complaining that they cannot make decisions correctly. This article describes virtual laboratory (VL), an organization which can help managers make decision. The virtual laboratory based on Intra... Many corporations are complaining that they cannot make decisions correctly. This article describes virtual laboratory (VL), an organization which can help managers make decision. The virtual laboratory based on Intranet uses many methods to draw policies for the corporation by analyzing business processes. It is a tool for learning organization too. 展开更多
关键词 business process virtual laboratory system simulation
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Temporal and Spatial Distribution and Influence Systems of Spring Thunderstorms in 2013 in Sichuan Province
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作者 徐娓 《Agricultural Science & Technology》 CAS 2014年第12期2192-2196,2203,共6页
Based on the lightning monitoring data, automatic and routine weather station observation data in spring (March-May) of 2013 of Sichuan Province, the corresponding relationship between the spatial distribution and t... Based on the lightning monitoring data, automatic and routine weather station observation data in spring (March-May) of 2013 of Sichuan Province, the corresponding relationship between the spatial distribution and the different regions, and the characteristics of atmospheric circulation and evolution of influence the sys- tem were analyzed and summarized. The results show that: the lightning and thunderstorm showed great regional differences in the spring of 2013 in Sichuan Province and the thunderstorm activity period was not the same in different areas. Because of the change of atmospheric circulation, the influence system from March to May corresponding to the thunderstorms in Sichuan tended to be volatile, also. 展开更多
关键词 SPRING THUNDERSTORM Regional differences The circulation situation In- fluence system
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Current Share Control IC Design for Paralleled DC/DC Converters
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作者 陈海 赵梦恋 +1 位作者 吴晓波 严晓浪 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第7期1017-1022,共6页
To keep even current distribution among DC/DC converters in a paralleled power system,an automatic master-slave control (AMSC) current sharing scheme is presented,which was implemented by a current share control IC.... To keep even current distribution among DC/DC converters in a paralleled power system,an automatic master-slave control (AMSC) current sharing scheme is presented,which was implemented by a current share control IC. A current feedback loop for output voltage adjustment is proposed for low signal distortion. Moreover,a special startup control logic is designed to improve startup timing and to speed up the initial current sharing. It was completed in 1.5μm bipolar-CMOS-DMOS (BCD) technology with an area of 3.6mm^2 . Using it,a paralleled power system of two DC/DC converters capable of outputting 12V/3A was built. Experimental results show that the current sharing error at full load is kept within 1%. 展开更多
关键词 DC DC converters Electric potential Signal distortion
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Simulation study on combustion system of tankless gas water heater
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作者 邱步 张小松 窦礼亮 《Journal of Southeast University(English Edition)》 EI CAS 2010年第2期187-191,共5页
This paper simulates the combustion system of a regular tankless gas water heater under different static pressure conditions.The simulation results are in accordance with the test results.It proves that the used physi... This paper simulates the combustion system of a regular tankless gas water heater under different static pressure conditions.The simulation results are in accordance with the test results.It proves that the used physical and mathematical models are reasonable.The results show that the flame height and the excess air ratios depend on the system pressure drop but not on the absolute pressure at the combustion chamber.The pressure drop and the amount of combustion air have an inverse relationship with CO generation,and they also impact on the temperature and velocity fields.To reduce CO emission,a stronger fan is needed to provide extra pressure head to ensure that enough combustion air is introduced into the system.This study provides a useful research tool to develop products through computational fluid dynamic analysis and laboratory testing. 展开更多
关键词 tankless gas water heater combustion system CO emission computational fluid dynamics(CFD) static pressure
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Design and research on a variable ballast system for deep-sea manned submersibles 被引量:7
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作者 邱中梁 《Journal of Marine Science and Application》 2008年第4期255-260,共6页
Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a su... Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected. 展开更多
关键词 DEEP-SEA manned submersible variable ballast system WEIGHT seawater pump seawater hydraulic system
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Modeling and optimization of unbalanced multi-stage logistic system
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作者 徐杭 徐榕 叶庆泰 《Journal of Southeast University(English Edition)》 EI CAS 2005年第2期220-224,共5页
To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each ... To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each stage, the Pruefer number is used. With theimproved decoding procedure, any Pruefer number produced stochastically can be decoded to a feasiblelogistic pattern, which can match with the capacities of the nodes of the logistic system. Withthese two innovations, a new modeling method based on parameterized interface distribution and thePriifer number coding is put forward. The corresponding genetic algorithm, named as PIP-GA, can findbetter solutions and require less computational time than st-GA. Although requiring a little moreconsumption of memory, PIP-GA is still an efficient and robust method in the modeling andoptimization of unbalanced multi-stage logistic systems. 展开更多
关键词 LOGISTICS optimization genetic algorithm Priifer number spanning tree parameterized interface distribution unbalanced multi-stage logistic system
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THE FORMATION AND DEVELOPMENT OF A MESOSCALE CONVECTIVE SYSTEM WITH HEAVY RAINFALL ALONG SOUTH CHINA COASTAL AREA 被引量:6
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作者 蒙伟光 张艳霞 +1 位作者 戴光丰 闫敬华 《Journal of Tropical Meteorology》 SCIE 2008年第1期57-60,共4页
Observational analysis shows that a Mesoscale Convective System (MCS) occurred on May 13-14 2004 along the coastal area in South China. The MCS initiated among the southwesterly flows within a west-east orientation lo... Observational analysis shows that a Mesoscale Convective System (MCS) occurred on May 13-14 2004 along the coastal area in South China. The MCS initiated among the southwesterly flows within a west-east orientation low-level shear line. Associated with the system, in its subsequent development stages, no distinct vortex circulation developed in low-level. Instead, a cyclonic flow disturbance was observed in the mid-troposphere. How the convection starts to develop and evolve into a MCS With observational analysis and numerical simulation, the problem has been studied. The high-resolution MM5 simulation shows that topographic convergence along the coastal line and the nearby mountains in western South China plays an important role to initiate the MCS convection. Once the convection occurs, due to the condensation heating, a cooperative interaction between the preexisting mid-level disturbance and convection is created, which may greatly affect the MCS development during periods when the system continues moving eastward. Compared to some typical MCS that happen in Southern China, which are usually accompanied with upward development of cyclonic vorticity, the development and evolution of the investigated MCS shows distinguishing features. In this article, the physical mechanisms responsible for the intensification of mid-level disturbance are discussed, and a viewpoint to interpret the effects of mid-level disturbance on the MCS organizational development is proposed. 展开更多
关键词 topographic convergence mid-level disturbance mesoscale convective system (MCS) numericalsimulation
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The Impact of the Eastward Propagation of Convective Systems over the Tibetan Plateau on the Southwest Vortex Formation in Summer 被引量:9
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作者 FU Shen-Ming SUN Jian-Hua +1 位作者 ZHAO Si-Xiong LI Wan-Li 《Atmospheric and Oceanic Science Letters》 2010年第1期51-57,共7页
Based on the temperature of the black body (TBB),station observed and NCEP reanalysis data,the impacts of the eastward propagation of convective cloud systems over the Tibetan Plateau on the southwest vortex (SWV) for... Based on the temperature of the black body (TBB),station observed and NCEP reanalysis data,the impacts of the eastward propagation of convective cloud systems over the Tibetan Plateau on the southwest vortex (SWV) formation that occurred at 1800 UTC on 29 June 2003 are analyzed by using the Zwack-Okossi (Z-O) equation to diagnose the thermal and dynamic processes.It is found that,in summer,severe convective activities often occur over the Tibetan Plateau due to the abundant supply of moisture.The convective cloud near the east edge of the plateau could move eastward with a shortwave trough in the westerly.The divergent center that is induced by latent heat release,which is associated with severe convective activities,moves out with the convective cloud and contributes to the low level decompression which is favorable for the formation of plateau edge cyclogenesis (PEC).The Z-O equation indicates that,in this case,the latent heat release and convergence are the two most important factors for SWV formation,which amounts to about 42% and 15% of the term TOTAL,respectively.It is implied that the thermal process effect was more important than the dynamic process during SWV formation. 展开更多
关键词 Tibetan Plateau southwest vortex convective system temperature of the black body latent heat release plateau edge cyclogenesis
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