Development characteristics and controlling factors of fractures in lacustrine shale and their geological significance for evaluating shale oil sweet spots in the third member of the Shahejie Formation in the Qikou Sag, Bohai Bay Basin

Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in these areas when structural fractures are present and the source, and storage spaces are separated.

Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab quality.In order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT software.Results show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either side.As the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes uneven.Although increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

Spatial-temporal Characteristics of Green Development Efficiency and Influencing Factors in Restricted Development Zones:A Case Study of Jilin Province,China

Green development is an important issue of sustainable development in China.Due to the relatively backward economy and the fragile ecological environment,restricted development zones need to embrace green development.Taking 38 counties in Jilin Province as the empirical research objects,and based on cross-sectional data for each county in 2005,2010,and 2015,we accurately depicted the spatiotemporal evolutionary characteristics of green development efficiency(GDE)in restricted development zones of Jilin Province using the slacks-based measure-data envelope analysis(SBM-DEA)model.Moreover,the factors that influence GDE were further analyzed using the Tobit model.We found that:first,GDE showed a V-shaped trend in restricted development zones of Jilin Province.The differences in GDE in the eastern,central,and western Jilin Province increased gradually.Second,76%of counties in the restricted development zones had high or higher efficiencies.The resource-based cities were the main areas with low or lower GDE.Third,the economic development level was the core factor affecting GDE.Urbanization level had a significant negative effect on GDE in the restricted development zones.The effect of technological innovation level on GDE fluctuated,and we found that a‘backward mechanism’of technological innovation was beginning to form.Industrial structure and environmental governance had no significant effects on GDE.

Spatial Pattern Evolution and Industrial Characteristics of Economic and Technological Development Zones and High-tech Industrial Zones in China

Economic and technological development zone and high-tech industrial zone are important types of development zone in China,and there are differences in their connotation and goal setting.In this paper,basic data of national and provincial economic and technological development zones and high-tech industrial zones in China were collected and arranged.Kernel density analysis and other GIS spatial analysis techniques were used to analyze the evolution laws of spatial patterns of economic and technological development zones and high-tech industrial zones in cities from 2006 to 2018.First,the agglomeration intensity was compared by measuring the degree of regional agglomeration and dispersion on the two time nodes.Next,kernel density method was used to explore the evolution of the two in the spatial layout and location,and analyze development commonness and difference of economic and technological development zones and high-tech industrial zones.Finally,the trend and reason of spatial evolution of development zones with different leading industries were explored.Research results show that:①the agglomeration degree of layout of high-tech industrial zones is stronger than that of economic and technological development zones,and there are similarities and differences in distribution trend of spatial patterns of the two types of development zones;②the distribution of labor-intensive,capital-intensive and technology-intensive development zones is concentrated at smaller scales and dispersed at larger ones;③although there are differences between the economic and technological development zones and the high-tech industrial zones in the goal,support,structure and function,management system and so on,their spatial development presents a trend of convergence.In the future,when enhancing urban-rural planning and public administration,governments should combine the trend of industrial transformation and upgrading,and optimize spatial layout of development zones by adjusting industrial structure,layout,transportation and land use.

Investment Promotion for Development Zones in China:Underlying Rationale and Policy Options

Development zones(DZs)have emerged as a significant policy initiative for promoting regional coordination and facilitating resources allocation.They serve as an organizational framework for fostering industrial agglomeration and driving high-quality development.DZs attract and accommodate resource factors,firms,and projects,thereby functioning as a central catalyst for economic growth.This study utilizes data collected at the“DZ,City and Countrycountry”levels through manual compilation,textual analysis,and innovation measurement.It aims to empirically examine the theoretical rationale and practical preferences for promoting business and investment in China’s DZs.This study considers several factors such as industry attribute,firm attribute,agglomeration theory,and industrial chain layout.Based on our research findings,DZs exhibit distinct preferences.First,industry attribute:DZs align with both national and regional strategic planning and adhere to the industrial endowments of the respective areas.Second,firm attribute:DZs prioritize attracting firms that are productive and innovative,and have an international presence,rather than those that primarily contribute to taxes and job creation.Third,DZs are guided by the agglomeration theory,which suggests that they prefer firms that generate strong agglomeration externalities.Lastly,DZs also consider the industrial chain layout,aiming to attract firms that not only align with their existing industrial strengths but also extend to the upstream and downstream supply chain links.These conclusions are substantiated by the performance of robustness test.The success of DZs in China can be attributed to the five key principles:Adherence to national and regional strategic planning,prioritizing the actual industrial foundation,incorporating the theory of agglomeration externalities,strengthening corporate competitiveness,and expanding industrial chains.

Spatiotemporal Evolution Characteristics of Urban Land Surface Temperature Based on Local Climate Zones in Xi’an Metropolitan,China

Local climate zones(LCZs)are an effective nexus linking internal urban structures to the local climate and have been widely used to study urban thermal environment.However,few studies considered how much the temperature changed due to LCZs transformation and their synergy.This paper quantified the change of urban land surface temperature(LST)in LCZs transformation process by combining the land use transfer matrix with zonal statistics method during 2000–2019 in the Xi’an metropolitan.The results show that,firstly,both LCZs and LST had significant spatiotemporal variations and synchrony.The period when the most LCZs were converted was also the LST rose the fastest,and the spatial growth of the LST coincided with the spatial expansion of the built type LCZs.Secondly,the LST difference between land cover type LCZs and built type LCZs gradually widened.And LST rose more in both built type LCZs transferred in and out.Finally,the Xi’an-Xianyang profile showed that the maximum temperature difference between the peaks and valleys of the LST increased by 4.39℃,indicating that localized high temperature phenomena and fluctuations in the urban thermal environment became more pronounced from 2000 to 2019.

Failure characteristics and fracture mechanism of overburden rock induced by mining:A case study in China

This study employs similar simulation testing and discrete element simulation coupling to analyze the failure and deformation processes of a model coal seam's roof.The caving area of the overburden rock is divided into three zones:the delamination fracture zone,broken fracture zone,and compaction zone.The caving and fracture zones'heights are approximately 110 m above the coal seam,with a maximum subsidence of 11 m.The delamination fracture zone's porosity range is between 0.2 and 0.3,while the remainder of the roof predominantly exhibits a porosity of less than 0.1.In addition,the numerical model's stress analysis revealed that the overburden rock's displacement zone forms an'arch-beam'structure starting from 160 m,with the maximum and minimum stress values decreasing as the distance of advancement increases.In the stress beam interval of the overburden rock,the maximum value changes periodically as the advancement distance increases.Based on a comparative analysis between observable data from on-site work and numerical simulation results,the stress data from the numerical simulation are essentially consistent with the actual results detected on-site,indicating the validity of the numerical simulation results.

Spatial Protection and Development of Traditional Mountain Settlements from the Perspective of Self-organization : A Case Study of Anju Ancient Town in Tongliang District, Chongqing

Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant characteristics of traditional mountain settlements were analyzed, and then its internal and external influencing factors were summarized. Finally, appropriate protection and development strategies were proposed, such as reasonably planning functional zones, breaking through the single structure, and creating a good living cultural environment. The innovation of this study is that it integrates the self-organization theory into the cognition of traditional mountain settlement space, and discusses the connection between the mountain settlement space and the traditional regional context under the modern development concept, so as to seek the benign protection and reasonable development of traditional mountain settlement space.

Development Characteristics of Private P.E Economy

The regional policy in the innovation development of private P.E economy plays better role in management according to law,guidance and escort;increase the macro quality of main body of private P.E entrepreneurs and the overall staff quality,develop P.E vocational P.E to provide P.E talents for private P.E economy.

Rural sustainable development:A case study of the Zaozhuang Innovation Demonstration Zone in China

Sustainable development is the central theme of modern global development.With the arrival of the urban era,the vulnerability and instability of rural areas have significantly increased,and rural sustainable development faces serious challenges.To address these issues,the study took the Zaozhuang Innovation Demonstration Zone in China under the National Sustainable Development Agenda as a case,combined with economic,social and land use data during 2016-2020,and applied Granger causality test method to explore the theoretical and practical pathways of“innovation-driven rural sustainable development”.The results showed that rural sustainable development and economic sustainability displayed a trend of synergistic change,with“explosive”growth from 2018 to 2020.The social sustainability steadily increased from 2016 to 2020.Ecological and spatial sustainability continuously declined during the study period.Moreover,the rural innovation capacity of the Zaozhuang Innovation Demonstration Zone displayed rapid growth during 2016-2020.Although the rural innovation capacity of the Zaozhuang Innovation Demonstration Zone has rapidly improved,it has a weak driving effect on rural sustainable development and economic sustainability.There are two primary challenges that must be overcome to ensure the rural sustainable development of the Zaozhuang Innovation Demonstration Zone.The first challenge is the imbalance among the multi-dimensional relationships in the process of rural sustainable development,and the second challenge is the weakening of rural innovation capacity to drive rural sustainable development.To overcome these challenges,this study proposed a systematic pathway for rural sustainable development in the Zaozhuang Innovation Demonstration Zone from multidimensions,such as policy actions,technologies,projects,and institutional guarantees,and formed a universal and representative“Zaozhuang model”.This study expands the theoretical foundation of rural sustainable development and provides theoretical and practical support for innovation-driven rural sustainable development.

Constructing demonstration zones to promote the implementation of Sustainable Development Goals

After the United Nations Agenda 2030 was officially launched in September 2015,governments around the world have taken actions to implement the ambitious plan.This paper summarizes the actions and policies taken in China for promoting the implementation of the UN’2030 Agenda for Sustainable Development,with emphasis on promoting the development of demonstration zones for delivery of the Sustainable Development Goals(SDGs).The Chinese government has taken two types of measures.One is to formulate a series of national plans and strategies and the other is to construct pilot and demonstration zones.Two approaches were presented to optimize the selection criteria for demonstration zones:a problem-based approach;and a major function-based approach.Both provided priority regions and major themes for selection and construction of demonstration zones.Suggestions for promoting the development of demonstration zones include:(1)building a monitoring system for the implementation of SDGs in each demonstration zone and establishing an open online platform to track the progress;(2)forming an effective stakeholder participation mechanism.The experiences in constructing innovation-driven demonstration zones are insightful for other countries to take practical actions in the delivery of SDGs.

Migration and accumulation characteristics of natural gas hydrates in the uplifts and their slope zones in the Qiongdongnan Basin,China

Various factors controlling the accumulation of natural gas hydrates(NGHs)form various enrichment and accumulation modes through organic combination.This study mainly analyzes the geological and geophysical characteristics of the NGHs occurrence in the uplifts and their slope zones within the deep-water area in the Qiongdongnan(QDN)Basin(also referred to as the study area).Furthermore,it investigates the dominant governing factors and models of NGHs migration and accumulation in the study area.The results are as follows.(1)The uplifts and their slope zones in the study area lie in the dominant pressure-relief direction of fluids in central hydrocarbon-rich sags in the area,which provide sufficient gas sources for the NGHs accumulation and enrichment through pathways such as gas chimneys and faults.(2)The top and flanks of gas chimneys below the bottom simulating reflectors(BSRs)show high-amplitude seismic reflections and pronounced transverse charging of free gas,indicating the occurrence of a large amount of gas accumulation at the heights of the uplifts.(3)Chimneys,faults,and high-porosity and high-permeability strata,which connect the gas hydrate temperature-pressure stability zones(GHSZs)with thermogenic gas and biogenic gas,form the main hydrate migration system.(4)The reservoir system in the study area comprises sedimentary interlayers consisting of mass transport deposits(MTDs)and turbidites.In addition,the reservoir system has developed fissure-and pore-filling types of hydrates in the pathways.The above well-matched controlling factors of hydrate accumulation enable the uplifts and their slope zones in the study area to become the favorable targets of NGHs exploration.

Development Paths of Characteristic Towns in Underdeveloped Areas in Central China——A Case Study of Yichun,Jiangxi

The demonstration effect triggered by the construction of Zhejiang's characteristic towns has attracted attention and learning from all over the country,and has set off a boom in building characteristic towns across the country. Under the dual constraints of industrial development and resource intensive use,the undeveloped areas of central China must find suitable development paths for characteristic towns. Taking Yichun City as an example,this article analyzes the advantages of Yichun City for developing characteristic towns combining its natural and economic conditions. In addition,the characteristic town development paths,such as vigorously promoting the construction of urban facilities,highlighting the characteristics relying on existing small towns,constructing an industrial chain of " ecology + leisure",highlighting cultural charm,and improving development grade,are proposed to provide useful reference for the development of characteristic towns in this type of underdeveloped cities in central China.

Microstructural zones and tensile characteristics of friction stir welded joint of TC4 titanium alloy

TC4 titanium alloy was friction stir welded using a W-Re pin tool,and the defect-free weld was produced with proper welding parameters.The joint consists of stir zone,heat affected zone and base material.The stir zone is characterized by equiaxed dynamically recrystallized α phases and transformed β phases with fine α+β lamellar microstructure.The microstructure of the heat-affected zone is similar to that of the base material,but there is an increase in the volume fraction of β.Transverse tensile strength of the joint is 92% that of the base material,and the joint is fractured in the stir zone and the fracture surface possesses typical plastic fracture characteristics.The stir zone is the weakest part of the joint,through which the tensile characteristics of the TC4 joint can be explained.

Green development model and cultivating path for characteristic small town

In the context of the new urbanization,the characteristic town,as a new hotspot to developing rapidly to explore the industry,humanities,community integration town model,a urbanization and high-tech industry development booster,by the government and developers attention.At the same time,the green development model applies to the characteristic town of industrial upgrading and transformation,guiding the future characteristic town of green economic industry development direction.This paper studies the green development model of the characteristic town,and puts forward the implementation of the green industry through the greening industry structure,promoting green consumption and optimizing the green management.

Characteristics and development model of karst reservoirs in the fourth member of Sinian Dengying Formation in central Sichuan Basin,SW China

The reservoir space,types and distribution characteristics of karst carbonate gas reservoirs in the fourth member of Sinian Dengying Formation(Deng 4 Member)in central Sichuan Basin are analyzed based on the drilling,logging and seismic data.A development model of karst reservoirs is constructed to support the high-efficiency development of gas pools.The research shows that the reservoirs in Deng 4 Member have mainly small-scale karst vugs and fractures as storage space,and can be divided into three types,fracture-vug,pore-vug and pore types.The development patterns of the karst reservoirs are determined.On the plane,the karst layers increase from 65 m to 170 m in thickness from the karst platform to the karst slope,and the high-quality reservoirs increase from 25.0 m to 42.2 m in thickness;vertically,the reservoirs at the top of Deng 4 Member appear in multiple layers,and show along-bedding and along fracture dissolution characteristics.The reservoirs at the bottom are characterized by the dissolution parallel to the water level during the karstification period,and have 3-5 large-scale fracture-cave systems.Based on the reservoir development characteristics and the genetic mechanism,three types of reservoir development models of karst reservoir are established,i.e.,bed-dissolved body,fracture-dissolved body and paleohorizon-dissolved body.The construction of karst reservoir development models and seismic response characteristics of the three types of reservoirs can provide parameter for well placement and trajectory design,and substantially improve productivity and development indices of individual wells and gas reservoirs.The designed production capacity of the gas reservoir has enhanced from the initial 3.6 billion to 6 billion cubic meters,making the profit of the reservoir development increase noticeably.

The Development Characteristics and Trends of Heavy Launch Vehicles

Heavy launch vehicles represent the ability of a country to enter space and utilize space resources. In re-cent years, with the growth in human space exploration, the major aerospace powers and companies in the world areplanning to develop heavy launch vehicles. This study analyzes the development of heavy launch vehicles in the world,reviews the characteristics of China's heavy launch vehicle serial configuration, and then proposes common points anddevelopment trends of future heavy launch vehicles in the world.

Sedimentary characteristics comparison and genesis analysis of the deepwater channel in the hydrate enrichment zones on the north slope of the South China Sea

Natural gas hydrate(NGH) is one of the important clean energy at present and even in the future. The study of its sedimentary environment and minerogenetic condition has long been a hot issue that has received much concern from geologists all over the world. China has successfully obtained the samples of NGH in Shenhu and Dongsha sea areas in 2007, 2013 and 2015, respectively. From this, the continental slope north of the South China Sea becomes an important test site for the study of NGH sedimentary genesis and minerogenetic condition. NGH has been found in Shenhu, Dongsha and Qiongdongnan areas within the continental slope north of South China Sea,at different depths of water, with different sedimentary characteristics, gas genesis, and minerogenetic conditions.Using a seismic sedimentology theory, combining seismic facies results of each facies, sedimentary facies and evolution of each area are documented in turn establishing a sedimentary model by considering palaeogeomorphology, sea level change and tectonic movement. The channel system and MTD(Mass Transport Deposition) system among these three areas were compared focusing on the developing position, appearance and controlling factors. Relative location among three areas is firstly defined that Dongsha area in a nearprovenance steep upper slope, Shenhu area in a normal gentle slope and Qiongdongnan area in an awayprovenance flat plain. Besides, their channel systems are classified into erosional, erosional-aggradational and aggradational channel, and MTD systems into headwall domain, translational domain and toe domain.

Dynamical Control of Asymmetrically Oblique Tidal Currents to the Sedimentary Characteristics and Development of Linear Sand Ridges in the Liaodong Shoal, East Bohai Sea

The Liaodong Shoal is a group of linear sand ridges located in the east Bohai Sea of China.In this study,54 surface sediment samples have been collected,current measurements at 4 stations have been carried out and bathymetric data were obtained.The current directions are rightward deflected relative to the strikes of the sand ridges.Affected by the narrowing effect of the ridge,the current velocities exhibited an anti-‘C’type vertical profile.The velocities of the lower currents linearly correlate with the water depths.The near-bed current velocities over the troughs are estimated to be higher than those over the ridges,and this feature could be explained by the loss of kinetic energy together with the conversion between kinetic energy and gravitational potential energy.The sedimentary characteristics that are compatible with the tidal dynamics are developed across the ridges and troughs,including grain size compositions,grain size parameters,mineral compositions and Dhm indexes.The existence of the angles between the current directions and the strikes of the sand ridges is the key factor for the growth of the sand ridges.The asymmetric hydrodynamic features between the flood and ebb currents lead to the differences in the topographical and sedimentary characteristics on both sides of a sand ridge.Insufficient material supply led to the degradation of the sand ridges,and the reduction of the tidal current intensity has led to the development of the subordinate sand ridges in the troughs.Sand ridges are migrating.