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
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
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
A dense seismic network was installed in the capital region of China in recent years,which makes it possible to resolve the focal mechanisms of small earthquakes. We gathered large earthquake focal mechanisms from the...A dense seismic network was installed in the capital region of China in recent years,which makes it possible to resolve the focal mechanisms of small earthquakes. We gathered large earthquake focal mechanisms from the last fifty years and moderate or small earthquake focal mechanisms from between 2002 and 2004,and calculated the present tectonic stress field of the capital region by the grid search method, which weighs different sized earthquakes and can improve the accuracy of the stress field inversion. The analysis of inversion results of different sub-regions shows that the azinuth of the maximum principal compressive stress axis is NE43°- 86° in the Beijing-Zhangjiakou-Datong area,NE38°-86° in the Tangshan area,and NE79°- 81° in the Xingtai area. Inversion results of this paper are similar to previous results,which proves the correctness of the approach. As revealed by the results,the stress field of the capital region is characterized by overall consistency and sub-regional differences. This study provides reference for earthquake mechanism explanation and geodynamics research.展开更多
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
Source spectra,corner frequency and zero frequency amplitudes in near-source conditions were measured using waveform data from 989 earthquakes with magnitudes larger than ML2.0 observed by the Beijing Digital Telemetr...Source spectra,corner frequency and zero frequency amplitudes in near-source conditions were measured using waveform data from 989 earthquakes with magnitudes larger than ML2.0 observed by the Beijing Digital Telemetry Seismic Network in the Capital Circle Region of China and its surrounding areas from January 2002 to June 2006 by the Brune model.Relevant formulas that were used for the calculation of dynamic source parameters include rupture radius,seismic moment,seismic energy,stress drop,and apparent stress.Scaling relations and characteristics of temporal-spatial variations of these dynamic parameters before the MS5.1 Wenan earthquake in Hebei Province that occurred on July 20,2006 were analyzed.Results show that apparent stress,stress drop,and the ratio of seismic energy to the rupture radius had relatively high values in some areas before the Wenan earthquake.These high-value concentration areas were mainly distributed in the North China Plain seismic zone.As is seen from the time curves,parameters,such as apparent stress,stress drop,and ratio of seismic energy to rupture radius underwent significant ascending processes before the Wenan earthquake,but the variation in the corner frequency showed a descending trend.This result might be related to the enhancement of stress in the North China Plain seismic zone before the earthquake.展开更多
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
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
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
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
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
Comprehensive statistical analysis was performed on the basic features of focal mechanisms of 619 ML≥2. 0 earthquakes which occurred in the capital circle area from January 2002 to June 2010. By dividing the capital ...Comprehensive statistical analysis was performed on the basic features of focal mechanisms of 619 ML≥2. 0 earthquakes which occurred in the capital circle area from January 2002 to June 2010. By dividing the capital area into three studying regions based on regional tectonic characteristics,cluster analysis was conducted on the focal mechanisms of all subregions using the longest distance method in the statistical cluster analysis to study the characteristics of tectonic stress tensors. The result shows that dominant P-axis azimuth distribution is NNE-NEE and that of T-axis is NNW-NWW,most of the focal areas are controlled by a horizontal stress field and rupture is mainly of horizontal strike-slip. The maximum principal compression stress orientation is NE75° in the west,NE62° in the middle,and near EW in the east of the capital area. The regional tectonic stress field is characterized by horizontal compression.展开更多
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
To explore the green development of automobile enterprises and promote the achievement of the“dual carbon”target,based on the bounded rationality assumptions,this study constructed a tripartite evolutionary game mod...To explore the green development of automobile enterprises and promote the achievement of the“dual carbon”target,based on the bounded rationality assumptions,this study constructed a tripartite evolutionary game model of gov-ernment,commercial banks,and automobile enterprises;introduced a dynamic reward and punishment mechanism;and analyzed the development process of the three parties’strategic behavior under the static and dynamic reward and punish-ment mechanism.Vensim PLE was used for numerical simulation analysis.Our results indicate that the system could not reach a stable state under the static reward and punishment mechanism.A dynamic reward and punishment mechanism can effectively improve the system stability and better fit real situations.Under the dynamic reward and punishment mechan-ism,an increase in the initial probabilities of the three parties can promote the system stability,and the government can im-plement effective supervision by adjusting the upper limit of the reward and punishment intensity.Finally,the implementa-tion of green credit by commercial banks plays a significant role in promoting the green development of automobile enter-prises.展开更多
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
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
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
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
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
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
基金Supported by the General Program of Natural Science Foundation of Shandong Province(No.ZR2020MD063)the Youth Program of Natural Science Foundation of Shandong Province(No.ZR2013DQ025)the National Natural Science Foundation of China and Shandong Province Joint Funds(No.U1706214)。
文摘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.
基金jointly sponsored by the National Basic Research Program of China(973 Program)(Grant No.2013CB430202)the National Natural Science Foundation of China(Grant No.41401056)+1 种基金the China Meteorological Administration Special Public Welfare Research Fund(Grant No.GYHY201406001)the Research Innovation Program for College Graduates of Jiangsu Province(Grant No.KYLX15 0858)
文摘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.
文摘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.
基金sponsored by the Special Fund of Fundamental Scientific Research Operating Expenses for Higher School of Central Government(Projects for creation teams ZY20110101)the Special Fund for the Earthquake Scientific Research of China(201208009)National Natural Science Foundation of China(41074072)
文摘A dense seismic network was installed in the capital region of China in recent years,which makes it possible to resolve the focal mechanisms of small earthquakes. We gathered large earthquake focal mechanisms from the last fifty years and moderate or small earthquake focal mechanisms from between 2002 and 2004,and calculated the present tectonic stress field of the capital region by the grid search method, which weighs different sized earthquakes and can improve the accuracy of the stress field inversion. The analysis of inversion results of different sub-regions shows that the azinuth of the maximum principal compressive stress axis is NE43°- 86° in the Beijing-Zhangjiakou-Datong area,NE38°-86° in the Tangshan area,and NE79°- 81° in the Xingtai area. Inversion results of this paper are similar to previous results,which proves the correctness of the approach. As revealed by the results,the stress field of the capital region is characterized by overall consistency and sub-regional differences. This study provides reference for earthquake mechanism explanation and geodynamics research.
文摘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.
基金the Special Research Fund for Earthquake Science,China (200708023)
文摘Source spectra,corner frequency and zero frequency amplitudes in near-source conditions were measured using waveform data from 989 earthquakes with magnitudes larger than ML2.0 observed by the Beijing Digital Telemetry Seismic Network in the Capital Circle Region of China and its surrounding areas from January 2002 to June 2006 by the Brune model.Relevant formulas that were used for the calculation of dynamic source parameters include rupture radius,seismic moment,seismic energy,stress drop,and apparent stress.Scaling relations and characteristics of temporal-spatial variations of these dynamic parameters before the MS5.1 Wenan earthquake in Hebei Province that occurred on July 20,2006 were analyzed.Results show that apparent stress,stress drop,and the ratio of seismic energy to the rupture radius had relatively high values in some areas before the Wenan earthquake.These high-value concentration areas were mainly distributed in the North China Plain seismic zone.As is seen from the time curves,parameters,such as apparent stress,stress drop,and ratio of seismic energy to rupture radius underwent significant ascending processes before the Wenan earthquake,but the variation in the corner frequency showed a descending trend.This result might be related to the enhancement of stress in the North China Plain seismic zone before the earthquake.
文摘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.
基金This study was supported by the Major State Basi(No.G1999043808) Youth Fund of the National 863 Project(No.G2002AA639350) and the Scientific Foundation of the Chinese
文摘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.
基金The National Natural Science Foundation of China under contract No.41376012.
文摘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.
基金Supported by the National Natural Science Foundation of China Enterprise Innovation and Development Joint Fund Project(U19B6003-01)Scientific research and technology development project of China National Petroleum Corporation(2021DJ3103).
文摘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.
基金This paper is one of achievements of the Chinese Academy of Sciences " Knowledge Innovation Project" item(KZCX2- 113).
文摘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.
基金funded jointly by China Spark Program of Earthquake Science and Technology(XH12001)Special research fund and Task contract of earthquake trend tracing in 2013 of Beijing Earthquake Administration(2013020109)
文摘Comprehensive statistical analysis was performed on the basic features of focal mechanisms of 619 ML≥2. 0 earthquakes which occurred in the capital circle area from January 2002 to June 2010. By dividing the capital area into three studying regions based on regional tectonic characteristics,cluster analysis was conducted on the focal mechanisms of all subregions using the longest distance method in the statistical cluster analysis to study the characteristics of tectonic stress tensors. The result shows that dominant P-axis azimuth distribution is NNE-NEE and that of T-axis is NNW-NWW,most of the focal areas are controlled by a horizontal stress field and rupture is mainly of horizontal strike-slip. The maximum principal compression stress orientation is NE75° in the west,NE62° in the middle,and near EW in the east of the capital area. The regional tectonic stress field is characterized by horizontal compression.
文摘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.
基金supported by the National Natural Science Foundation of China(71973001).
文摘To explore the green development of automobile enterprises and promote the achievement of the“dual carbon”target,based on the bounded rationality assumptions,this study constructed a tripartite evolutionary game model of gov-ernment,commercial banks,and automobile enterprises;introduced a dynamic reward and punishment mechanism;and analyzed the development process of the three parties’strategic behavior under the static and dynamic reward and punish-ment mechanism.Vensim PLE was used for numerical simulation analysis.Our results indicate that the system could not reach a stable state under the static reward and punishment mechanism.A dynamic reward and punishment mechanism can effectively improve the system stability and better fit real situations.Under the dynamic reward and punishment mechan-ism,an increase in the initial probabilities of the three parties can promote the system stability,and the government can im-plement effective supervision by adjusting the upper limit of the reward and punishment intensity.Finally,the implementa-tion of green credit by commercial banks plays a significant role in promoting the green development of automobile enter-prises.
基金supported by the National Natural Science Foundation of China(51375035 and 51075014)the Research Fund for the Doctoral Program of Higher Education of China(20121102110021)
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.