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Research on the River-Crossing Development Process and Dynamic Mechanism in Nanchang City 被引量:1
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作者 赵晓杰 吴巍 胡细英 《Agricultural Science & Technology》 CAS 2017年第12期2635-2637,共3页
With the deepening of the market economy and the big step of urbaniza- tion, the spatial restricted effect of the development of the riverside cities in China is becoming more and more obvious. The river-crossing deve... With the deepening of the market economy and the big step of urbaniza- tion, the spatial restricted effect of the development of the riverside cities in China is becoming more and more obvious. The river-crossing development of cities is imperative. The Riverside New Area has gradually become the key area of urban development and the new economy growth pole. Based on the development history of Nanchang, the evolution of the river-crossing development of Nanchang city was analyzed systematically, and river-crossing development of Nanchang was divided into 3 stages of initial river-crossing development stage, slow river-crossing develop- ment stage and rapid river-crossing development stage. In-depth discussion was made to the dynamic mechanism of the river-crossing development in Nanchang. 展开更多
关键词 Nanchang River-crossing development dynamic mechanism
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Atmospheric Circulation and Dynamic Mechanism for Persistent Haze Events in the Beijing–Tianjin–Hebei Region 被引量:63
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作者 Ping WU Yihui DING Yanju LIU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第4期429-440,共12页
In this study, regional persistent haze events(RPHEs) in the Beijing–Tianjin–Hebei(BTH) region were identified based on the Objective Identification Technique for Regional Extreme Events for the period 1980–201... In this study, regional persistent haze events(RPHEs) in the Beijing–Tianjin–Hebei(BTH) region were identified based on the Objective Identification Technique for Regional Extreme Events for the period 1980–2013. The formation mechanisms of the severe RPHEs were investigated with focus on the atmospheric circulation and dynamic mechanisms. Results indicated that:(1) 49 RPHEs occurred during the past 34 years.(2) The severe RPHEs could be categorized into two types according to the large-scale circulation, i.e. the zonal westerly airflow(ZWA) type and the high-pressure ridge(HPR) type. When the ZWA-type RPHEs occurred, the BTH region was controlled by near zonal westerly airflow in the mid–upper troposphere.Southwesterly winds prevailed in the lower troposphere, and near-surface wind speeds were only 1–2 ms^-1. Warm and humid air originating from the northwestern Pacific was transported into the region, where the relative humidity was 70% to 80%, creating favorable moisture conditions. When the HPR-type RPHEs appeared, northwesterly airflow in the mid–upper troposphere controlled the region. Westerly winds prevailed in the lower troposphere and the moisture conditions were relatively weak.(3) Descending motion in the mid-lower troposphere caused by the above two circulation types provided a crucial dynamic mechanism for the formation of the two types of RPHEs. The descending motion contributed to a reduction in the height of the planetary boundary layer(PBL), which generated an inversion in the lower troposphere. This inversion trapped the abundant pollution and moisture in the lower PBL, leading to high concentrations of pollutants. 展开更多
关键词 Beijing–Tianjin–Hebei region regional persistent haze events atmospheric circulation dynamic mechanism
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Study on numerical simulation and dynamic mechanism of win-ter- time circulation in the eastern China seas 被引量:1
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作者 韩冬 侯一筠 +2 位作者 魏泽勋 刘兴泉 赵喜喜 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2004年第4期327-334,共8页
An MOM2 based 3-dimentional prognostic baroclinic Z-ordinate model was established to study the circulation in eastern China seas, considering the topography, inflow and outflow on the open boundary, wind stress, temp... An MOM2 based 3-dimentional prognostic baroclinic Z-ordinate model was established to study the circulation in eastern China seas, considering the topography, inflow and outflow on the open boundary, wind stress, temperature and salinity exchange on the sea surface. The results were consistent with observation and showed that the Kuroshio intrudes in large scale into the East China Sea continental shelf East China, during which its water is exchanged ceaselessly with outer sea water along Ryukyu Island. The Tsushima Warm Current is derived from several sources, a branch of the Kuroshio, part of the Taiwan Warm Current, and Yellow Sea mixed water coming from the west of Cheju Island. The water from the west of Cheju Island contributes ap-proximately 13% of the Isushima Warm Current total transport through the Korea Strait. The circulation in the Bohai Sea and Yellow Sea is basically cyclonic circulation, and is comprised of coastal currents and the Yellow Sea Warm Current. Besides simulation of the real circulation, numerical experiments were conducted to study the dynamic mechanism. The numerical experiments indicated that wind directly drives the East China Sea and Yellow Sea Coastal Currents, and strengthens the Korea Coastal Current and Yellow Sea Warm Current. In the no wind case, the kinetic energy of the coastal current area and main YSWC area is only 1% of that of the wind case. Numerical experiments also showed that the Tsushima Warm Current is of great importance to the formation of the Korea Coastal Current and Yellow Sea Warm Current. 展开更多
关键词 eastern China seas wintertime CIRCULATION MOM2 numerical simulation dynamic mechanism
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A study on tourism development model with dynamic mechanism of circular economy 被引量:1
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作者 WU Li-yun DONG Suo-cheng CHEN Fang-ying 《Ecological Economy》 2010年第4期439-446,共8页
With the social and economic development,conflict among the shortage of resources,environmental destruction and economic development is ever more pronounced.In this context,the circular economy was gradually accepted.... With the social and economic development,conflict among the shortage of resources,environmental destruction and economic development is ever more pronounced.In this context,the circular economy was gradually accepted.Guided by sustainable development concept and promoted by six external forces,tourism circular economy take tourism micro-cycle model as the core,implement in corporate and social levels,improve resource utilization efficiency,reduce tourism's adverse impacts on the surrounding environment through recycling,reducing and reusing resources,achieve economic,social and environmental development of the organic unity. 展开更多
关键词 Tourism circular economy Development model dynamic mechanism
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Dynamic Mechanism of Migmatization in the Dabie Complex, Northeastern Hubei, China
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作者 Wang Jianghai, Guangzhou Institute of New Geological Technology, Academia Sinica, Guangzhou,GuangdongYang Wenhua and Wu Jinping China U niversity of Geosciences, W uhan, Hubei Jiang M inxi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1995年第2期135-154,共20页
On the basis of the detailed field work, compositions and contents of plagioclase and K - feldspar,determination of ordering degree, statistical analysis of plagioclase elongation index, mass-balance calculation and m... On the basis of the detailed field work, compositions and contents of plagioclase and K - feldspar,determination of ordering degree, statistical analysis of plagioclase elongation index, mass-balance calculation and mineral spatial distribution and geochemistry, it is concluded that the migmatites in the Dabie complex are characterized by the presence of thermocenters. There are regular changes in mineral character in the migmatites from the centers outwards. The dominant genetic mechanism is anatexis and metasomatism, whose intensities decrease from the centers outwards. Finally, according to the simulated experiment on Liesegang' s rings and non-linear dynamics (dissipative structure theory), the dynamic mechanism of migmatization is profoundly expouded as consisting of the early-stage metasomatism induced by the thermal anomaly, the cardinal-stage anatexis induced by the early-stage matasomatism and finally the last-stage post-anatexis metasomatism. 展开更多
关键词 Dabie complex MIGMATITES dynamic mechanism dissipative structure diffusion inverse to concentration gradients
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Observational characteristics and dynamic mechanism of low-salinity water lens for the offshore detachment of the Changjiang River diluted water in August 2006
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作者 Zhenyu Liu Wenjing Zhang +1 位作者 Xuejun Xiong Shouxian Zhu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第3期34-45,共12页
The Changjiang River diluted water(CDW)spreads into the East China Sea(ECS)primarily in a plume pattern,although in some years,low-salinity water lenses(LSWLs)detach from the main body of the CDW.In-situ observations ... The Changjiang River diluted water(CDW)spreads into the East China Sea(ECS)primarily in a plume pattern,although in some years,low-salinity water lenses(LSWLs)detach from the main body of the CDW.In-situ observations indicate that in August 2006,a LSWL detached from the main body of the CDW near the river mouth.In this paper,the effects of winds,tides,baroclinity and upwelling on LSWLs are explored with a threedimensional model.The results show that:(1)winds play a crucial role in these detachment events because windinduced northerly Eulerian residual currents impose an uneven force on the CDW and cut it off,thus forming a LSWL;(2)upwelling carries high-salinity water from the lower layer to the upper layer,truncating the low-salinity water tongue vertically,which is conducive to the detachment and maintenance of LSWLs;and(3)upwelling during the evolution of a LSWL is caused by the combined effects of winds and tides.The influences of windinduced upwelling are mainly near the shore,whereas the upwelling along the 30 m isobath is predominantly affected by tides,with the effect increasing from neap tide to spring tide. 展开更多
关键词 Changjiang River diluted water low-salinity water lens numerical simulation observational characteristics dynamic mechanism upwelling
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Geological structure and dynamic mechanism of the Termit rift basin in West African rift system
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作者 WANG Tao YUAN Shengqiang +4 位作者 LI Chuanxin MAO Fengjun PANG Sichen JIANG Hong ZHENG Fengyun 《Petroleum Exploration and Development》 CSCD 2022年第6期1339-1350,共12页
Based on seismic and drilling data in the study area,the geological structure and kinematic process of the Termit rift basin were studied using seismic profile interpretation and balanced restoration to find out the d... Based on seismic and drilling data in the study area,the geological structure and kinematic process of the Termit rift basin were studied using seismic profile interpretation and balanced restoration to find out the dynamic mechanism of the basin.(1)The geological structure of the Termit Basin is represented as a narrow rift basin,with development of series of structural styles in extensional,extensional strike-slip and compressional stress setting.On plane,it is narrow in the north and wide in the south,and transitions from graben to half-graben from north to south;it features a graben controlled by the boundary faults in the north and a fault-overlapped half-graben in the south.(2)Before the Cretaceous,a series of hidden faults developed in the West African rift system,which laid the foundation for the development location and distribution direction of the Termit Basin;during the Cretaceous to Paleogene periods,the basin experienced two phases of rifting in Early Cretaceous and Paleogene,which controlled the initial structure and current structural shape of the basin respectively;during the Neogene to Quaternary,the basin was subjected to weak transformation.(3)In the Precambrian,the Pan-African movement gave rise to a narrow and long weak zone within the African plate,which provided the pre-existing structural conditions for the formation of the Termit Basin.In the Early Cretaceous,affected by the South Atlantic rifting,the Pan African weak zone was reactivated,resulting in the first stage of rifting and the basic structural framework of the Termit Basin.In the Paleogene,affected by the subduction and convergence of the Neo-Tethys Ocean,the African-Arabian plate extended in near E-W trending,and the Termit Basin experienced the second stage of rifting.The oblique extension in this period caused intense structural differentiation,and the current structural pattern of alternate uplifts and depressions took shape gradually. 展开更多
关键词 West African rift system Termit Basin CRETACEOUS rift basin basin geological structure dynamic mechanism NIGER
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Study on Dynamic Mechanism of Urban Expansion: A Case Study of Shandong Province
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作者 Zhang Xiaoqing Ren Jianlan 《Chinese Journal of Population,Resources and Environment》 北大核心 2007年第3期37-42,共6页
This paper aims at studying the dynamic mechanism of urban expansion and its role. Based on the economic model of urban spatial structure and applying panel data in Shandong Province, the paper concludes. Economic gro... This paper aims at studying the dynamic mechanism of urban expansion and its role. Based on the economic model of urban spatial structure and applying panel data in Shandong Province, the paper concludes. Economic growth and transition of economic structure have played the most powerful role in urban expansion. An increase in population helps the core to extend. Increasing agricultural productivity can provide a countervailing force. An increase in transportation costs will limit urban expan- sion. An increase in the marginal productivity of land in housing production will increase urban expansion. Fiscal and taxation policies also have encouraged the extensive shift of cultivated land into build-up area. This paper also suggests that if high rate increasing GDP is needed, the urban core will continue to expand. The government should take measures to improve the rapid growth of the city. 展开更多
关键词 urban extent dynamic mechanism economic modelof urban spatial structure panel data
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Spatial differentiation and dynamic mechanism of micro-geomorphology based on acoustic spectrum data of the Huanghe(Yellow)River Delta
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作者 Ping LI Yongde JIN +1 位作者 Wei GAO Xiaolong ZHAO 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第6期2077-2089,共13页
Submarine micro-geomorphology is a geo-morphological type occurring in shallow and surface areas of seabed.The combined relationships and distribution of the micro-geomorphology indirectly reflect coupling relationshi... Submarine micro-geomorphology is a geo-morphological type occurring in shallow and surface areas of seabed.The combined relationships and distribution of the micro-geomorphology indirectly reflect coupling relationships among the sediment deposition,dynamic environment,and geomorphologic evolution.Spatial differentiation and dynamic changes in micro-geomorphology were studied based on acoustic data interpretation from a wide range(3200 km^(2))of the Huanghe(Yellow)River delta(HRD).The combination of the sub-bottom profiler and the side-scan sonar methods allowed for the identification of submarine shallow micro-geomorphologic types,as well as their scale and spatial distributions.There were seven typical micro-geomorphologic features in the shallow and surface areas of the HRD,including buried ancient channels,stratigraphic disturbances,scour troughs,sand waves,pits,erosional remnants,and sand spots.The coupling and superposition of the sediment,sediment characteristics,seabed scouring and silting,and hydrodynamic conditions of the Huanghe River had combined effects on the patterns of micro-geomorphologic types,characteristics,and ranges.From the perspective of acoustic profile interpretations,the scale,range,and spatial locations of the microgeomorphology in the HRD revealed seasonal variation characteristics,and the spatial distributions displayed significant regional differentiation characteristics.In addition,strong stratigraphic disturbances and areas with densely distributed buried ancient channels reflected the activity and instability of the submarine shallow strata.Through the interpretation of the sub-bottom profile detection data,the diversion processes of the flow paths in the lower reaches of the Huanghe River were obtained for a certain historical period in the coastal waters of the HRD.This study further clarified the relationships between the micro-geomorphologic features and spatial combinations,which is important for research on micro-geomorphologic features and their dynamic mechanisms. 展开更多
关键词 Huanghe(Yellow)River delta(HRD) micro-geomorphology acoustic reflection characteristics spatial differentiation dynamic mechanisms
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The Dynamic Mechanisms for the Formation of Primary Metal Zoning of Cassiterite-Sulfide Deposits in the Gejiu Metallogenic Province, Yunnan
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作者 Yu Chongwen Jiang Yaosong China University of Geosciences, Beijing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1991年第1期51-63,共13页
Copper and tin in cassiterite-sulfide deposits of the Gejiu metallogenic province are intimately associatedand show peculiar primary metal zoning. The authors made use of computer techniques to simulatenumerically the... Copper and tin in cassiterite-sulfide deposits of the Gejiu metallogenic province are intimately associatedand show peculiar primary metal zoning. The authors made use of computer techniques to simulatenumerically the zoning of these ore deposits. The study shows that the regular spatial zoning probably resultedfrom the succession of multiple, intermittent and pulsatory mineralizations, The successive transports with di-verse velocities along channelways of the ore-forming solutions, taking place under conditions of definite dif-ference between metal concentrations, in solutions and wallrocks, followed by differential deposition, consti-tute possible dynamic mechanisms for the primary metal zoning. 展开更多
关键词 Met rate The dynamic mechanisms for the Formation of Primary Metal Zoning of Cassiterite-Sulfide Deposits in the Gejiu Metallogenic Province YUNNAN
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Morphological Evolution and Dynamic Mechanism of Hubei Village during 1949-2021
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作者 FU Lianlin 《Journal of Landscape Research》 2021年第4期14-18,共5页
Since the reform and opening up,Shenzhen has experienced rapid urbanization.Modern urban landscape has replaced the original traditional village landscape,followed by the loss of urban features and the demise of tradi... Since the reform and opening up,Shenzhen has experienced rapid urbanization.Modern urban landscape has replaced the original traditional village landscape,followed by the loss of urban features and the demise of traditional villages.To change the phenomenon,with the help of town plan analysis method,the historical process of urban material form is looked back on.Combining the theory of evolution mechanism of urban spatial structure,and taking Hubei Village which is the only traditional village in the central district of Shenzhen as an example,the characteristics and causes of evolution of traditional villages in Shenzhen in different periods are analyzed,and the evolution characteristics of plane pattern are summarized.Moreover,the power source and characteristics of urban renewal in Shenzhen are pointed out from the perspective of government,market and social force,and the focus of promoting the renewal of traditional villages in the future is explored. 展开更多
关键词 Morphological evolution dynamic mechanism Hubei Village Traditional village
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Biomechanical and dynamic mechanism of locust take-off 被引量:7
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作者 Dian-Sheng Chen Jun-Mao Yin +1 位作者 Ke-Wei Chen Zhen Li 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第5期762-774,共13页
The biomimetic locust robot hopping vehicle has promising applications in planet exploration and reconnaissance. This paper explores the bionic dynamics model of locust jumping by using high-speed video and force anal... The biomimetic locust robot hopping vehicle has promising applications in planet exploration and reconnaissance. This paper explores the bionic dynamics model of locust jumping by using high-speed video and force analysis. This paper applies hybrid rigid-flexible mechanisms to bionic locust hopping and studies its dynamics with emphasis laid on the relationship between force and jumping performance. The hybrid rigid-flexible model is introduced in the analysis of locust mechanism to address the principles of dynamics that govern locust joints and mechanisms during energy storage and take-off. The dynamic response of the biomimetic mechanism is studied by considering the flexi- bility according to the locust jumping dynamics mechanism. A multi-rigid-body dynamics model of locust jumping is established and analyzed based on Lagrange method; elastic knee and tarsus mechanisms that were proposed in previous works are analyzed alongside the original bionic joint configurations and their machinery principles. This work offers primary theories for take-off dynamics and establishes a theoretical basis for future studies and engineering applications. 展开更多
关键词 Locust take-off- dynamics Hybrid rigid- flexible Hopping mechanism
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Influencing Factors and Dynamic Mechanism of Industrial Structure from the Perspective of Supply-side Reform 被引量:2
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作者 Deng GAO Shuhui SHAO 《Asian Agricultural Research》 2018年第12期37-40,共4页
The supply-side reform is an important measure for the high-quality development of China's economy in the new era. The purpose of this paper is to explore the mechanism and influence of technological progress,huma... The supply-side reform is an important measure for the high-quality development of China's economy in the new era. The purpose of this paper is to explore the mechanism and influence of technological progress,human capital,consumption demand,resource endowment and government intervention on the adjustment and upgrading of industrial structure,and to deepen the understanding of supply-side reform. 展开更多
关键词 Supply-side REFORM INDUSTRIAL structure Influencing FACTORS dynamic mechanism
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RESIDENTIAL SPACE DIFFERENTIATION OF NANJING METROPOLIS AND ITS DYNAMIC MECHANISM IN 1912-1998
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作者 ZHU Xi-gang WU Qi-yan CUI Gong-hao(Department of Urban and Resource Science, Nanjing University Nanjng 210093, P.R.China)(Architecture Deportment, Kunming University of Technology Kunming 650051, P.R.China) 《Chinese Geographical Science》 SCIE CSCD 2000年第2期125-130,共6页
Since 1978, within social geographic pattern of Chinese metropolis, differentiation not only has come to be in social entity,. but also by some degree embodied within residential space. Through the 8tudy on spatial se... Since 1978, within social geographic pattern of Chinese metropolis, differentiation not only has come to be in social entity,. but also by some degree embodied within residential space. Through the 8tudy on spatial segregation, the authors implicate these above spatial differentiation from social polarization to residential segregation cause by change in the political economy, in the organization of urban and real estate development (from project-specific to comprehensive development and real estate development) and in the functions and value of urban planning (from a sectional-subordinated to a municipally based control). The imprints of transition on social space are illustrated eight references to the example of Nanjing metropolis. Among the new phenomenal identified here are the six types of residential area according to soci-economic status. 展开更多
关键词 RESIDENTIAL SPACE DIFFERENTIATION dynamic mechanism NANJING METROPOLIS
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Compensation:A Synchronic Dynamic Mechanism in Language
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作者 Ma Qinghua Wang Zhiguang 《宏观语言学》 2008年第1期14-37,共24页
In this paper, compensation mechanism—a synchronic dynamic rule in language is postulated and theorized. The rule raises the acceptability of clauses by effecting the positive side of some variations with exceptional... In this paper, compensation mechanism—a synchronic dynamic rule in language is postulated and theorized. The rule raises the acceptability of clauses by effecting the positive side of some variations with exceptional expression and offsetting their negative side. This mechanism is determined by the instrumentality and systematicality of language so that its basic principle should be applicable to all exceptional expressions for particular positive effects and thus universal synchronically. 展开更多
关键词 COMPENSATION SYNCHRONIC dynamic mechanism ACCEPTABILITY
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ANALYSIS OF STRUCTURAL STYLES OF THE BASIN-RANGE SYSTEMS IN THE CENTRAL CHINA OROGENIC CHAIN OF YANGTZE VALLEY AND THE DYNAMIC MECHANISM
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作者 HU Bao- qing and ZENG Qiao- song ( Changsha Institute of Geotectonics,Chinese Academy of Sciences,Changsha 410013,China) 《Geotectonica et Metallogenia》 2000年第1期63-74,共12页
Basin and orogenic belt belong to the same tectonic system which has close connections in spatial distribution and dynamic mechanism.Structural styles analysis of basin- range system, not only may rebuild basin- ra... Basin and orogenic belt belong to the same tectonic system which has close connections in spatial distribution and dynamic mechanism.Structural styles analysis of basin- range system, not only may rebuild basin- range coupling process and landscape evolution of orogenic belt and its adjacent basin, but also become the foundation in exploring how orogenesis controls landform,climate,resources,energy and environment etc.In the light of geodynamic mechanism,three main types of basin- range system may be classified,namely,stretch,compression and strike- slip.In combination with their geotectonic settings and plate movement phases, a comprehensive classification scheme may be educed for structural styles of basin- range system.Natural disasters and geo- ecological environment in the Yangtze Valley have been restricted and impressed by crustal movement and Qinling- Dabie etc.orogenesis since the Mesozoic and Cenozoic.In terms of collocating relation and contacting basin prototype and orogenic belt around the basin for cause of formation, typical structural styles of basin- range system on the central orogenic chain within the Yangtze Valley consist of coupling Tongbo- Dabie orogenic belt and Jianghan- Dongtin fault basin on the northern margin of the central Yangtze landmass, and coupling Qinling- Daba mountain margin thrust- faulted orogenic belt and Sichuan foreland basin on the northern margin of upper- Yangtze landmass.The paper analyzes evolutionary features of two typical structural styles of basin- range system during syn- orogenic, late- orogenic and post- orogenic stages,and probes into their dynamic mechanism.It is emphasized that,in different stages of basin- range system of different properties and basin- mountain transformation process,different structural styles may be formed;and different associations of structural styles can form different types of natural disasters complex and eco- environment systems. 展开更多
关键词 Structural styles basin- range system dynamic mechanism the central OROGENIC CHAIN the YANGTZE VALLEY
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On the Dynamic Mechanism of the Constitutional System in Promoting Economic Development -- Analysis of the Institutional Economics
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作者 Lin Xiaowen 《学术界》 CSSCI 北大核心 2015年第1期266-270,共5页
According to the basic principles of institutional economics,the Constitutional system is the underlying causes to promote the economic development.The CPC Central Committee is the source of motivation to promote econ... According to the basic principles of institutional economics,the Constitutional system is the underlying causes to promote the economic development.The CPC Central Committee is the source of motivation to promote economic development by the startup mechanism of Constitution am endment,and the political interpretation of the Constitution is the basic way to promote economic development.The economic development in China has challenged the Constitutional system,calling for the appropriate adjustments to the Constitutional system so as to maintain the sustainable and stable development of the economy in China. 展开更多
关键词 经济发展 启动机制 经济学分析 体制 持续稳定发展 制度经济学 中国经济 修正案
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A molecular dynamics study on mechanical performance and deformation mechanisms in nanotwinned NiCo-based alloys with nano-precipitates under high temperatures
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作者 Zihao Yu Hongyu Wang +2 位作者 Ligang Sun Zhihui Li Linli Zhu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期349-355,共7页
Molecular dynamics simulations are performed to investigate the mechanical behavior of nanotwinned NiCo-based alloys containing coherent L12 nano-precipitates at different temperatures,as well as the interactions betw... Molecular dynamics simulations are performed to investigate the mechanical behavior of nanotwinned NiCo-based alloys containing coherent L12 nano-precipitates at different temperatures,as well as the interactions between the dislocations and nano-precipitates within the nanotwins.The simulation results demonstrate that both the yield stress and flow stress in the nanotwinned NiCo-based alloys with nano-precipitates decrease as the temperature rises,because the higher temperatures lead to the generation of more defects during yielding and lower dislocation density during plastic deformation.Moreover,the coherent L12 phase exhibits excellent thermal stability,which enables the hinderance of dislocation motion at elevated temperatures via the wrapping and cutting mechanisms of dislocations.The synergistic effect of nanotwins and nano-precipitates results in more significant strengthening behavior in the nanotwinned NiCo-based alloys under high temperatures.In addition,the high-temperature mechanical behavior of nanotwinned NiCo-based alloys with nano-precipitates is sensitive to the size and volume fraction of the microstructures.These findings could be helpful for the design of nanotwins and nano-precipitates to improve the high-temperature mechanical properties of NiCo-based alloys. 展开更多
关键词 NiCo-based alloys high temperature nano-precipitate NANOTWINS molecular dynamics simulation mechanical behavior deformation mechanism dislocations
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Dynamic Modeling and Experimental Verification of an RPR Type Compliant Paralle Mechanism with Low Orders
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作者 Shuang Zhang Jingfang Liu +1 位作者 Huafeng Ding Yanbin Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期83-94,共12页
Efficiency of calculating a dynamic response is an important point of the compliant mechanism for posture adjustment.Dynamic modeling with low orders of a 2R1T compliant parallel mechanism is studied in the paper.The ... Efficiency of calculating a dynamic response is an important point of the compliant mechanism for posture adjustment.Dynamic modeling with low orders of a 2R1T compliant parallel mechanism is studied in the paper.The mechanism with two out-of-plane rotational and one lifting degrees of freedom(DoFs)plays an important role in posture adjustment.Based on elastic beam theory,the stiffness matrix and mass matrix of the beam element are established where the moment of inertia is considered.To improve solving efficiency,a dynamic model with low orders of the mechanism is established based on a modified modal synthesis method.Firstly,each branch of the RPR type mechanism is divided into a substructure.Subsequently,a set of hypothetical modes of each substructure is obtained based on the C-B method.Finally,dynamic equation of the whole mechanism is established by the substructure assembly.A dynamic experiment is conducted to verify the dynamic characteristics of the compliant mechanism. 展开更多
关键词 Compliant parallel mechanism dynamic model Modal synthesis method dynamic experiment
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Dynamic analysis of a novel multilink-spring mechanism for vibration isolation and energy harvesting
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作者 谢佳衡 杨涛 唐介 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期366-379,共14页
Due to technical limitations,existing vibration isolation and energy harvesting(VIEH)devices have poor performance at low frequency.This paper proposes a new multilink-spring mechanism(MLSM)that can be used to solve t... Due to technical limitations,existing vibration isolation and energy harvesting(VIEH)devices have poor performance at low frequency.This paper proposes a new multilink-spring mechanism(MLSM)that can be used to solve this problem.The VIEH performance of the MLSM under harmonic excitation and Gaussian white noise was analyzed.It was found that the MLSM has good vibration isolation performance for low-frequency isolation and the frequency band can be widened by adjusting parameters to achieve a higher energy harvesting power.By comparison with two special cases,the results show that the MLSM is basically the same as the other two oscillators in terms of vibration isolation but has better energy harvesting performance under multistable characteristics.The MLSM is expected to reduce the impact of vibration on high-precision sensitive equipment in some special sites such as subways and mines,and at the same time supply power to structural health monitoring devices. 展开更多
关键词 multilink-spring mechanism nonlinear dynamics vibration isolation energy harvester
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