Surface and Deep Structure of the Hanshan-Wuwei Basins in the Lower Yangtze Region:Implications for Mesozoic Tectonic Evolution of the South China Block

Indicating the tectonic features of the Hanshan-Wuwei basin can reconstruct the framework of the basins formed in Mesozoic and further understand the Mesozoic tectonic evolution of the South China Block.Studies on surface structure,regional stress field and deep geophysical characteristics of the Mesozoic Hanshan-Wuwei basin in Lower Yangtze region were carried out.NE-NNE trending folds and faults developed in the northern margin of the basins.The reconstruction of tectonic stress fields indicates four stress stages dominating the basins'evolution including NW-SE compression,N-S compression,NW-SE extension and NWW-SEE compression.2D seismic profiles reveal coexistence of thrust,strike-slip and normal faults in the basin.Combined with regional geological studies,the geodynamic processes for the formation of the Hanshan-Wuwei basin can be divided into five stages:1)During the Late Triassic,EW trending foreland basin was formed by N-S compression;2)From Mid-Jurassic to Late Jurassic,continuous compression strengthened the foreland deformation and formed thrust nappes.In this stage,the integrated foreland basin was compartmentalized or fragmented,and transferred to the broken foreland basin;3)NE-trending sinistral strike-slip movement at the beginning of the Early Cretaceous;4)Regional extension resulted in normal faults and rift basins developing in the Late Cretaceous;5)The NWW-SEE compression at the end of the Late Cretaceous caused NW sinistral strike-slip faults to form,which partly transformed the rift basin.

Can Industrial Structure Upgrading Restrain Industrial Land Expansion?Evidence from China

China has made great achievements in industrial development and is transforming into a powerful manufacturing country.Meanwhile,the industrial land scale is also expanding.However,whether industrial structure upgrading achieves the purpose of restraining industrial land expansion remains unanswered.By calculating the industrial land structure index(ILSI)and industrial land expansion scale(ILES),this study analyzed their temporal and spatial distribution characteristics at both regional and city levels from 2007to 2020 in China.Results show that industrial land expansion presents a different trend in the four regions,the ILES in the eastern region is the largest,and the speed of industrial land expansion has declined since 2013,but it has gradually increased since 2016.The ILSI of the eastern and central regions is higher than that of the western and northeastern regions.Furthermore,a spatial Durbin model(SDM)has been established to estimate the spatial effect of industrial structure upgrading on industrial land expansion from 2007 to2020.Notably,industrial structure upgrading has not slowed industrial land expansion.The eastern and western regions require a greater amount of industrial land while upgrading the industrial structure.The improvement of the infrastructure level and international trade level has promoted industrial land expansion.

Experimental investigation on pyrolysis products and pore structure characteristics of organic-rich shale heated by supercritical carbon dioxide

The efficient pyrolysis and conversion of organic matter in organic-rich shale,as well as the effective recovery of pyrolysis shale oil and gas,play a vital role in alleviating energy pressure.The state of carbon dioxide(CO_(2))in the pyrolysis environment of shale reservoirs is the supercritical state.Its unique supercritical fluid properties not only effectively heat organic matter,displace pyrolysis products and change shale pore structure,but also achieve carbon storage to a certain extent.Shale samples were made into powder and three sizes of cores,and nitrogen(N_(2))and supercritical carbon dioxide(ScCO_(2))pyrolysis experiments were performed at different final pyrolysis temperatures.The properties and mineral characteristics of the pyrolysis products were studied based on gas chromatography analysis,Xray diffraction tests,and mass spectrometry analysis.Besides,the pore structure characteristics at different regions of cores before and after pyrolysis were analyzed using N_(2) adsorption tests to clarify the impact of fracturing degree on the pyrolysis effect.The results indicate that the optimal pyrolysis temperature of Longkou shale is about 430℃.Compared with N_(2),the oil yield of ScCO_(2) pyrolysis is higher.The pyrolysis oil obtained by ScCO_(2) extraction has more intermediate fractions and higher relative molecular weight.The ScCO_(2) can effectively improve the pore diameter of shale and its effect is better than that of N_(2).The micropores are produced in shale after pyrolysis,and the macropores only are generated in ScCO_(2) pyrolysis environments with temperatures greater than 430℃.The pore structure has different development characteristics at different pyrolysis temperatures,which are mainly affected by the pressure holding of volatile matter and products blocking.Compared to the surface of the core,the pore development effect inside the core is better.With the decrease in core size,the pore diameter,specific surface area,and pore volume of cores all increase after pyrolysis.

Study upon the Spatial Structure of Regional Eco-tourism-Based upon the Perspective of Supply and Demand and Competition Field

Along with the coming of the low-carbon era, people have paid more and more attention to the natural environment and eco-tourism will embrace a huge development. From the perspectives of the market relationship of supply-demand in economics and of field competition in physics, this paper has discussed upon the present status of the spatial structure of eco-tourism, and analyzed the relationship between supply-demand and field, in order to clarify the direction for the balance between supply and demand in the field and to guide eco-tourism to the way of sustainable development.

Geological structure of the yellow sea area from regional gravity and magnetic interpretation

Regional gravity and aeromagnetic data covering the area of 32°- 38° N, 118°-127° E at the scale of 1：1,000,000 are coordinated and integrated in a synthetic study of the South China Yellow Sea and adjacent areas. Depth to magnetic crystalline basement and its structure are determined by magnetic anomaly inversion. Depth to and thickness of the Paleozoic rock are also revealed by gravity anomaly inversion with constrains of the basement and known seismic information from several profiles. Structure units, main faults, basin boundaries, and sub-suppressions are outlined on the basis of gravity data interpretation.

Empirical Study on Effect of Industrial Structure Change on Regional Economic Growth of Beijing-Tianjin-Hebei Metropolitan Region

Based on the data of gross domestic product(GDP),industrial added value and the proportion of industrial employees from 2000 to 2008,this paper studies the effect of industrial structure change on the regional economic growth of Beijing-Tianjin-Hebei Metropolitan Region in China using the shift-share method.The results show that:1) In the 21st century,the industrial output of three industries,namely,primary,secondary,and tertiary,and the GDP grew rapidly in the study period.The tertiary industry grew the fastest;it had the largest contribution to the GDP and mean-while had become the most competitive industry in the metropolitan region.2) The development of cities within the region was not balanced.Firstly,compared with Tianjin,Beijing,as one of the two core cities,was more rational in the industrial structure.Secondly,the surrounding eight cities,which are Shijiazhuang,Qinhuangdao,Tangshan,Langfang,Baoding,Cangzhou,Zhangjiakou,and Chengde,were all uncompetitive than the two core cities.3) There was a great industrial gradient in the region(especially between the two core cities and the cities of Tangshan,Baoding,Zhangjia-kou,Chengde,Cangzhou,and Langfang).As a result,it is foreseeable that the industry transfer in the Bei-jing-Tianjin-Hebei Metropolitan Region will be one of the trends in regional development,and the industry transfer is inevitably to promote the regional integration.

Models of Spatial Structures of Regional Multi-element Geochemical Anomalies over Copper-Polymetallic Orefields

Regional stream sediment surveys at a 1:200,000 scale reveal positive andnegative regional multi-element geochemical anomalies over medium to large copper-polymetallicorefields of different genetic types in China. Regional geochemical anomalies of orefield refer tothose geochemical anomalies that are related to metallogenesis of an orefield in a certain area. Theanomaly area is typically 10 to 100 km^2. The regional multi-element anomalies related tomineralization can be divided into three groups, that is, the ore-element anomaly association,indicator element anomaly association, and metallogenic environmental element anomaly association.Their common spatial distributions over ore deposits or orefields possess unique structures. Themodel of spatial structure of regional multi-element geochemical anomalies (RAGSS) of an orefielddelineates structural feature possessed by orderly spatial distributions of different groups ofmulti-element anomaly associations related to orefield metallogenesis. It is used to outline thecommon metallogenetic anomaly visage that is composed of the orderly spatial distribution ofdifferent groups of multi-element anomaly associations. The orderly spatial distribution ofmulti-element anomalies over an orefield reflects element distributions as they are changed from adispersed 'out-of-order' state into a concentrated 'orderly' state during the mineralization of anorefield. Three different patterns of the spatial anomaly structure related to mineralization in anorefield can be concluded: (1) nested pattern; (2) eccentric pattern and; (3) peripheral pattern.There are marked differences between multi-element anomaly patterns related and not related tomineralization. RAGSS models of orefields can be used to better understand and evaluate regionalmulti-element anomalies and identify ore types.

Joint Inversion of the 3D P Wave Velocity Structure of the Crust and Upper Mantle under the Southeastern Margin of the Tibetan Plateau Using Regional Earthquake and Teleseismic Data

The special seismic tectonic environment and frequent seismicity in the southeastern margin of the Qinghai-Tibet Plateau show that this area is an ideal location to study the present tectonic movement and background of strong earthquakes in China's Mainland and to predict future strong earthquake risk zones. Studies of the structural environment and physical characteristics of the deep structure in this area are helpful to explore deep dynamic effects and deformation field characteristics, to strengthen our understanding of the roles of anisotropy and tectonic deformation and to study the deep tectonic background of the seismic origin of the block＇s interior. In this paper, the three-dimensional （3D） P-wave velocity structure of the crust and upper mantle under the southeastern margin of the Qinghai-Tibet Plateau is obtained via observational data from 224 permanent seismic stations in the regional digital seismic network of Yunnan and Sichuan Provinces and from 356 mobile China seismic arrays in the southern section of the north-south seismic belt using a joint inversion method of the regional earthquake and teleseismic data. The results indicate that the spatial distribution of the P-wave velocity anomalies in the shallow upper crust is closely related to the surface geological structure, terrain and lithology. Baoxing and Kangding, with their basic volcanic rocks and volcanic clastic rocks, present obvious high-velocity anomalies. The Chengdu Basin shows low-velocity anomalies associated with the Quaternary sediments. The Xichang Mesozoic Basin and the Butuo Basin are characterised by low- velocity anomalies related to very thick sedimentary layers. The upper and middle crust beneath the Chuan-Dian and Songpan-Ganzi Blocks has apparent lateral heterogeneities, including low-velocity zones of different sizes. There is a large range of low-velocity layers in the Songpan-Ganzi Block and the sub-block northwest of Sichuan Province, showing that the middle and lower crust is relatively weak. The Sichuan Basin, which is located in the western margin of the Yangtze platform, shows high-velocity characteristics. The results also reveal that there are continuous low-velocity layer distributions in the middle and lower crust of the Daliangshan Block and that the distribution direction of the low-velocity anomaly is nearly SN, which is consistent with the trend of the Daliangshan fault. The existence of the low-velocity layer in the crust also provides a deep source for the deep dynamic deformation and seismic activity of the Daliangshan Block and its boundary faults. The results of the 3D P-wave velocity structure show that an anomalous distribution of high-density, strong-magnetic and high-wave velocity exists inside the crust in the Panxi region. This is likely related to late Paleozoic mantle plume activity that led to a large number of mafic and ultra-mafic intrusions into the crust. In the crustal doming process, the massive intrusion of mantle-derived material enhanced the mechanical strength of the crustal medium. The P-wave velocity structure also revealed that the upper mantle contains a low-velocity layer at a depth of 80-120 km in the Panxi region. The existence of deep faults in the Panxi region, which provide conditions for transporting mantle thermal material into the crust, is the deep tectonic background for the area＇s strong earthquake activity.

URBAN REGIONAL STRUCTURES TRANSFORMATION AND SUSTAINABLE DEVELOPMENT: CASE STUDY OF NANJING MEGALOPOLIS

s: Since 1978, many changes have happened on the background of urban regional structure in China, such as the economy system restructuring, the social transforming including the population flow accelerating and social demand diversifying and individualizing, the political and economic systems reforms, the rise of the real estate market and the changing relationship between human and nature. From the macroscopic view, these changes make the national urban system to be a newer pattern with a widening gap among the cities in spite of the rising of the cities as a whole. At the same, the urban land use structures are changing with both the trends of intensification and diversification, and the trends of the regional diversification and the economic integration. Besides, urban structures with multiple centers are emerging in several metropolitan areas in China. These changes and trends mentioned above are confirmed by a case study of Nanjing City, a growing metropolitan area in east China. The case study also points out some problems in urban regional structure reforming, especially the poor social and ecological considerations. We should pay more attention to some ideas like balance of intensification and decentralization, development of suburban centers and a reasonable mixing of the functional activities to develop a sustainable urban regional structure.

Analysis on The In？ uence of Regional Financial Development to The Upgrading of Regional Industrial Structure

This paper mainly introduces the regional , nance in detail,points out that the goal of industrial structure is more reasonable and advanced,expounds the influence of regional financial development on the upgrading of regional industrial structure,puts forward some suggestions for regional financial development to further promote the upgrading of the structure.

NUMERICAL CLASSIFICATION OF REGIONAL STRUCTURE OF AGRO-ECOSYSTEM IN GUANGDONG

On the basis of 'The Statistical Data of Guangdong Province in 1981' and the 14 selected original variables, 107 counties and suburbs in Guangdong are classified. In the classification, cluster analysis is applied, and the cluster hierarchy of the agro-ecosystem is achieved with a computer. According to output level, planting structure, and input level of energy, there is an evident regionalism in the agro-ecosystem of Guangdong, which presents approximately concentric circles centralized by Guangzhou City.

REGIONAL STRUCTURE OF CAPITAL MARKET OF FOREIGN DIRECT INVESTMENT IN CHINA’S MAINLAND

Since China's reform and open door, the countries and regions of direct investment in China's mainland have been increasing. In 1995, the amount of foreign direct investment (FDI) in China was US$ 37.81 billion that was from more than 170 countries and regions. The regional structure of capital market of FDI in China has three characteristics: (1) The most of FDI was from the near countries or regions, Hong Kong Macao, Taiwan, Japan, South Korea, Thailand and Malaysia provided 80.3% of the amount of FDI in 1995. (2) Only several countries and regions provided most of FDI in China. (3) According to the contributory rate, the main capital market of FDI in China could be divided into four classes, including the guiding market, subsidiary market, new and development market, opportunity market. Most of FDI in China was from the developing countries and regions, which had a negative effect on the size and technical level of foreign capital enterprises. The author puts forward the countermeasures to improve the regional structure of capital market: (1) to keep the guiding market stable, (2) to open up chiefly the subsidiary market, (3) to guide actively the new and developing market, (4) to try hard to start the opportunity market.

Mechanism of realizing industrial structure upgrading through technology-driven regional innovation capacity

Based on the analysis of the formation process of regional innovation capacity, this paper expatiates that the technology is the basis for industrial structure upgrading, while technological innovation is the power of regional innovation capacity. It points out that the essential of regional industrial structure upgrading is the transition of regional technology structure from one balance to another. The mechanism of realizing industrial structure upgrading through technology-driven regional innovation capacity is also discussed briefly.

The Enlightenment of Regional Spatial Structure Theory to Rural Revitalization Strategy

The rural revitalization strategy is a macro-strategic guide to solve the problem of"weak links"in the coordinated development of rural and urban regions.Geography responded positively to the national strategy and made a preliminary discussion on the scientific theoretical basis and research direction of rural revitalization strategy.The paper integrated application of the spatial structure theory of geography and the time-space research scientific thinking,respectively discussed the core edge theory,growth pole and point axis theory,theory of stage of industrialization and urbanization,rural settlement type,infrastructure construction patterns,such as the theoretical guidance and application of strategy of rejuvenating rural to rural revitalization of the full implementation of the strategy to provide theoretical support and practical guidance.

Classification of regional agricultural structure:method and its application to China

Regional agriculture is the basis of regional sustainable development, so sustainable regional agricultural development is essential to the sustainable development of the whole society and becomes the focus of global research. The classification of regional agricultural structure is the basic work of regional agriculture study. This paper constructs index system （27 indices） of regional agricultural structure types with the three big indices： natural resources, developmental level of the agro-economy, and agro-ecological conditions. This paper also endows weight to every sub-classification index by means of AHP and obtains the comprehensive evaluation value of the three types of indices with arithmetic average weight approach. The regional agricultural structure can be classified into eight types in accordance with this evaluation results. The empirical study of China shows that the 31 provinces （municipalities and autonomous regions） are of different agriculture structural types. Finally, countermeasures of sustainsable agricultural development are put forward for the different agriculture structure features.

An Empirical Research of Producer Services＇ Cluster Development To Regional Industrial Structure Optimization And Upgrading --Based on the Research of 16 central cities＇ Panel Data in Yangtze River Delta

Based on the 16 central cities＇ Panel Data in Yangtze River Delta, location quotient index is used in this paper to measure and analyze the current cluster situation of producer services in Yangtze River Delta, fixed effects model of Panel Data model is also used in this paper, and the industrial structure is taken as the dependent variable, while the core explanatory variables is the degree of producer services＇ cluster development, which is calculated by location quotient, moreover, three control variables introduced in this paper and they are technology advantage, education level and R＆D spending, and the mentioned above is to empirically study the impacts of producer services＇ cluster development to the regional industrial structure. As a result, producer services＇ cluster development has a significant positive role in promoting the regional industrial structure optimization and upgrading, though the extent is not yet a big push and is still to be further strengthened. In this paper, it has provided a strong evidence that under China＇ s new normal economy, producer services is badly needed to promote regional industrial structure, and finally it makes specific suggestions based on the current cluster situation of producer services in Yangtze River Delta.

A Study on Investment Structure of Fixed Assets and Regional Economic Growth

Nowadays,it has been in the period of rapidly developing China’s economy.Since the financial crisis in 2008,China has paid more and more attention to investing in fixed assets,and the growth rate of investing in fixed asset is also rising.However,when promoting regional economic growth,if we only pay attention to the total amount of fixed asset investment,there will inevitably exist some blindness and lack of sustainability.Therefore,the study between the investment structure of fixed assets and regional economic growth is quite important.China has a vast territory and many regions.The investment structure of fixed assets in different regions is also different,so the influence on economic growth is also different.This paper analyzes the investment structure of fixed assets and regional economic growth,and help realize the rapid growth of regional economy by recognizing the current situation of China's investment structure of fixed assets.

Three dimensional shear wave velocity structure of crust and upper mantle in South China Sea and its adjacent regions by surface waveform inversion

We assembled approximately 328 seismic records. The data set was from 4 digitally recording long-period and broadband stations of CDSN. We carried out the inversion based on the partitioned waveform inversion (PWI). It partitions the large-scale optimization problem into a number of independent small-scale problems. We adopted surface waveform inversion with an equal block (2((2() discretization in order to acquire the images of shear velocity structure at different depths (from surface to 430 km) in the crust and upper-mantle. The resolution of all these anomalies has been established with (check-board( resolution tests. These results show significant difference in velocity, lithosphere and asthenosphere structure between South China Sea and its adjacent regions.

Structural plane recognition from three-dimensional laser scanning points using an improved region-growing algorithm based on the robust randomized Hough transform

The staggered distribution of joints and fissures in space constitutes the weak part of any rock mass.The identification of rock mass structural planes and the extraction of characteristic parameters are the basis of rock-mass integrity evaluation,which is very important for analysis of slope stability.The laser scanning technique can be used to acquire the coordinate information pertaining to each point of the structural plane,but large amount of point cloud data,uneven density distribution,and noise point interference make the identification efficiency and accuracy of different types of structural planes limited by point cloud data analysis technology.A new point cloud identification and segmentation algorithm for rock mass structural surfaces is proposed.Based on the distribution states of the original point cloud in different neighborhoods in space,the point clouds are characterized by multi-dimensional eigenvalues and calculated by the robust randomized Hough transform(RRHT).The normal vector difference and the final eigenvalue are proposed for characteristic distinction,and the identification of rock mass structural surfaces is completed through regional growth,which strengthens the difference expression of point clouds.In addition,nearest Voxel downsampling is also introduced in the RRHT calculation,which further reduces the number of sources of neighborhood noises,thereby improving the accuracy and stability of the calculation.The advantages of the method have been verified by laboratory models.The results showed that the proposed method can better achieve the segmentation and statistics of structural planes with interfaces and sharp boundaries.The method works well in the identification of joints,fissures,and other structural planes on Mangshezhai slope in the Three Gorges Reservoir area,China.It can provide a stable and effective technique for the identification and segmentation of rock mass structural planes,which is beneficial in engineering practice.

Crust and Upper Mantle Electrical Resistivity Structure in the Panxi Region of the Eastern Tibetan Plateau and Its Significance

The Panxi region is located in the frontal zone of positive squeezing subduction and side squeezing shearing between the Indian plate and the Eurasian plate. The long-period magnetotelluric （LMT） and broadband magnetotelluric （MT） techniques are both used to study the deep electrical conductivity structure in this region; magnetic and gravity surveys are also performed along the profile. According to the 2-D resistivity model along the Yanyuan-Yongshan profile, a high- conductivity layer （HCL） exists widely in the crust, and a high-resistivity block （HRB） exists widely in the upper mantle in general, as seen by the fact that a large HCL exists from the western Jinpingshan tectonic zone to the eastern Mabian tectonic zone in the crust, while the HRB found in the Panxi tectonic zone is of abnormally high resistivity in that background compared to both sides of Panxi tectonic zone. In addition, the gravity and magnetic field anomalies are of high value. Combined with geological data, the results indicate that there probably exists basic or ultrabasic rock with a large thickness in the lithosphere in the Panxi axial region, which indicates that fracture activity once occurred in the lithosphere. As a result, we can infer that the high-resistivity zone in the Panxi lithosphere is the eruption channel for Permian Emeishan basalt and the accumulation channel for basic and ultrabasic rock. The seismic sources along the profile are counted according to seismic record data. The results indicate that the most violent earthquake sources are located at the binding site of the HRB and the HCL, where the tectonic activity zone is generally acknowledged to be; however, the earthquakes occurring in the HCL are not so violent, which reflects the fact that the HCL is a plastic layer, and the fracture threshold of a plastic layer is low generally, making high stress difficult to accumulate but easy to release in the layer. As a result, a higher number of smaller earthquakes occurred in the HCL at Daliangshan tectonic zone, and violent earthquakes occurred at the binding site of high- and low-resistivity blocks at the Panxi tectonic zone.