The Maichen Sag in the south-central part of the Beibuwan Basin is abundant in geothermal resources that have not been widely exploited and utilized due to inadequate research on it.This study evaluated the geothermal...The Maichen Sag in the south-central part of the Beibuwan Basin is abundant in geothermal resources that have not been widely exploited and utilized due to inadequate research on it.This study evaluated the geothermal resources in the Maichen Sag based on the regional geological setting and geothermal conditions.Grid units for assessment and a geological model for areas with geothermal resources were established using spatial analysis techniques.The spatial distribution models of the physical and thermophysical properties of the geothermal reservoirs were also built using the Kriging interpolation method.Based on the terrestrial heat flow distribution in the target areas,the spatial distribution of the geo-temperature field through the inversion under the constraints of the temperature data from boreholes were predicted.Factors such as deep geo-temperature,thermophysical properties of rocks,and terrestrial heat flow values,were integrated into this quantitative evaluation of geothermal resources through the geological modeling-based volume method and the geothermal reservoir engineering-based numerical simulation method.The results show that the Maichen Sag has favorable heat source conditions with intersected,deep-rooted faults and widely developed Upper Paleozoic fissured granite geothermal reservoirs.The northern outer slope zone at a burial depth of 3‒5 km on the tectonic plane of the basement in the sag is suggested to be a potential target area,where,as calculated using the volume method,is likely to be the home to the total geothermal resources of 80.4×10^(9)GJ(i.e.,2.75×10^(9)tonnes of coal equivalent(tce))in the bedrock geothermal reservoirs at a burial depth of 3‒6 km.The geotemperature of 172‒201℃at a formation depth of 5 km in the sag also indicates that the deep geothermal resources are of high value for exploitation.展开更多
The insect is the animal protein feed resource potential, the rapid repro- duction, large quantity, high protein content, and most species of insects can be used as livestock feed utilization, development of insect as...The insect is the animal protein feed resource potential, the rapid repro- duction, large quantity, high protein content, and most species of insects can be used as livestock feed utilization, development of insect as feed resources, to pro- mote the development of China's animal husbandry and feed industry, has important significance.展开更多
Rural tourism, i.e., agrotourism, is the newly-exploited tourism product[1] with agricultural production, rustic view, rural life and rural custom as the main carrier and with agriculture and countryside as the touris...Rural tourism, i.e., agrotourism, is the newly-exploited tourism product[1] with agricultural production, rustic view, rural life and rural custom as the main carrier and with agriculture and countryside as the tourism resources. Zhenjiang City is in possession of adequate source markets, abundant rural tourism resources, good tourist ecological environment and profound culture. The pleasant ecological environment and charming rural scenery provide the development of rural tourism in Zhenjiang with exceptional advantages. The exploitation of rural tourism not only promotes the exploitation and development of agricultural tourism in Zhenjiang, but also improves the structure of tourism product, simulating the healthy development of rural economy. Through the analysis of the exploitation advantage of the rural tourism resources in Zhenjiang, the author analyzed the exploitation situation and existing problems of the rural tourism resources in Zhenjiang. The author considered that the rural tourism development in Zhenjiang was lack of unified planning; the cultural content of tourism product was low; the development depth was not enough; the construction of infrastructure was lagging behind; and meanwhile, it was lacking of funding, tourism program and advertising promotion. In the light of the above deficiencies, a series of countermeasures of rural tourism exploitation was put forward, that is, to complete the exploitation planning of the rural tourism resources, promoting the cultural taste of the rural tourism product; to enhance the publicity of the rural tourism, highlighting the brand feature of local tourism and creating high-quality product; to conduct standard management, strengthening the training of tourism management personnel.展开更多
This study aimed to make an orientation for the development of Zhenjiang Pearl S.Buck tourism products.According to the spatial structure styles of tourism products,this paper discussed the exploitation of Zhenjiang P...This study aimed to make an orientation for the development of Zhenjiang Pearl S.Buck tourism products.According to the spatial structure styles of tourism products,this paper discussed the exploitation of Zhenjiang Pearl S.Buck tourism products from the perspective of spot products,linear products and network products.It expanded the Pearl S.Buck research to tourism science field and put forward some ideas of promoting the comprehensive benefits of Pearl S.Buck tourism resource as well as the exploitation of similar tourism products.展开更多
Natural environment of Hailuogou Scenic Area(Conch Gully)was introduced,and it was pointed out that tourist resources in the study area showed gradient differentiation along the vertical height.In view of such gradien...Natural environment of Hailuogou Scenic Area(Conch Gully)was introduced,and it was pointed out that tourist resources in the study area showed gradient differentiation along the vertical height.In view of such gradient differentiation,resource contents and characteristics of its cultural heritages zone,geothermal resources zone,forest vegetation zone,and glacial resources zone were respectively analyzed.Based on the gradient differentiation of tourist resources in Hailuogou Scenic Area,suggestions were given for its further tourism development,and it was stressed that brand effects of the attractions should be enhanced,infrastructure construction and maintenance of newly-explored scenic spots should be improved,and more efforts should be devoted to explore disastrous landform resources.This research is of practical significance for studying spatial differentiation and evolution mechanism of tourist resources in mountainous areas in western China,and also provides scientific support for the exploration of tourist resources in mountainous areas.展开更多
The paper had introduced geographic causes and types of hot springs, illustrated its disease-treating function and displayed its great vitality and widespread development prospect as tourist resources. By taking Shawa...The paper had introduced geographic causes and types of hot springs, illustrated its disease-treating function and displayed its great vitality and widespread development prospect as tourist resources. By taking Shawan Hot Spring in Xinjiang for example, the paper had analyzed its natural condition, hot springs and tourist economic development. And then, quantitative and qualitative analysis had been conducted on the quality of water environment resources in the research area. It had analyzed reasons for degeneration of water environment and studied exploitation and sustainable development of hot springs. It was considered that environment especially water environment quality had decreased since hot spring tourism development. In order to achieve sustainable development of hot springs and promotion of local tourism, it must be guided by environment treatment, and some strategies for sustainable development of hot springs had been proposed.展开更多
The society of today often likes to brand itself as modem, advanced, civilized, or a society of positive changes. However, it is a fact that the world is confronted with huge contradictions that oppose such qualificat...The society of today often likes to brand itself as modem, advanced, civilized, or a society of positive changes. However, it is a fact that the world is confronted with huge contradictions that oppose such qualifications. Obviously, one of the most striking and almost unbelievable realities tells us about inhumane and uncivilized actions of child exploitation in "entrepreneurial" purposes in the widest range of exploitation and abuse. Current period of economic crisis tells us even more about the rising crisis of moral, which is, in statistical terms, confirmed by a rising number of exploited children in a global framework, and even in some national frameworks as well. With that, some positive results about the diminishing number of exploited children are devaluated. The question is what are the "limits" of such behavior of groups, organizations, and individuals whose behavior is, obviously, tolerated in the frameworks of certain national economies. Does this behavior have clarity as a part of modem society? Or, even more severe, for how long can we as a society close our eyes in front of such facts? Do we even have the right? In this paper, the authors strive towards focusing and objectifying the global problem of exploitation and abuse of children in "entrepreneurial" purposes, primarily with the purpose of updating all parts of the society of this paradox and the need of raising the awareness and teaching all relevant factors--from institutions to individuals, with the purpose of resolving and more neutralize the equivalents of this uncivilized and non-entrepreneurial "phenomenon", as well as approaching the same in the framework of different actions with broadest measures possible and with all disposable assets.展开更多
On the basis of considering the heterogeneity and using the finite element numerical simulation, this thesis investi- gates the damage of the roof and coal as well as the failure of evolutionary process during the re-...On the basis of considering the heterogeneity and using the finite element numerical simulation, this thesis investi- gates the damage of the roof and coal as well as the failure of evolutionary process during the re-exploitation of the residual coal. According to the analysis of the damage field, stress field and the failure process, it explores the damage evolution, stress distribution laws and the damage models. Besides, this thesis puts forward the idea of penetrating and establishing drilling steels aimed at solving the problem of wall carving and roof fall, meanwhile this suggestion accomplishes the successful appli- cation effect in the testing ground. This thesis demonstrates that the re-exploitation of the residual coal can be carried out and the safe production can be ensured by adopting some measures. What's more, the research result provides the theoretical and practical experience for the re-exploitation of the residual coal in the similar conditions.展开更多
Groundwater over-exploitation is a major problem in groundwater development, utilization and protection. At present, the area of shallow groundwater over-exploitation in the High-tech Zone is 76 km^(2). In this study,...Groundwater over-exploitation is a major problem in groundwater development, utilization and protection. At present, the area of shallow groundwater over-exploitation in the High-tech Zone is 76 km^(2). In this study, the system and mechanism construction, engineering measure construction, and control effect of national comprehensive control project of groundwater over-exploitation areas in the High-tech Zone in 2020 were evaluated, and the comprehensive control of groundwater over-exploitation in the High-tech Zone in the year was summarized to provide effective basis for the continuous implementation of comprehensive control of groundwater over-exploitation. At the same time, the water-saving and exploitation reduction effect and generalizability of different measures were studied to provide useful reference for other over-exploitation areas.展开更多
America had been attempting to annex Canadian West and posed a threat to the security of the fledgling country. Therefore the antipathy towards America as well as independent-nation complex of Canadians drove Canadian...America had been attempting to annex Canadian West and posed a threat to the security of the fledgling country. Therefore the antipathy towards America as well as independent-nation complex of Canadians drove Canadian government to incorporate the west exploitation into the national strategy of creating an independent country. Canadian west exploitation thus took on some distinctiveness.展开更多
Calculated in terms of surface runoff plus irrepeated groundwater, there is about 8. 67 ×1010m3 of total available water resources in the inland river basins of arid Northwest China. Water resources is the decisi...Calculated in terms of surface runoff plus irrepeated groundwater, there is about 8. 67 ×1010m3 of total available water resources in the inland river basins of arid Northwest China. Water resources is the decisive factor for survival of oases and human being. But there have arisen several aspects of Serious eco-environment problems resulted from irrational exploitation and utilization. From now on, the development and utilization of water not only requires to promote regional economy, but also needs to protect and improve the environment based on their potential. Sustainable utilization needs to broaden new sources and saving water at first. Then three measures are recommended.展开更多
Firstly, the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer (salt deposit) in Qarhan Salt Lake was studied by using the Pitzer theory. Th...Firstly, the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer (salt deposit) in Qarhan Salt Lake was studied by using the Pitzer theory. The concept of macroscopic solubility product and its relation with accumulated ore dissolving ratio were presented, which are used in the numerical model of dissolving and driving exploitation of potassium salt in Qarhan Salt Lake. And secondly, with a model forming idea of transport model for reacting solutes in the multi-component fresh groundwater system in porous media being a reference, a two-dimensional transport model coupled with a series of chemical reactions in a multi-component brine porous system (salt deposits) was developed by using the Pitzer theory. Meanwhile, the model was applied to model potassium/magnesium transport in Qarhan Salt Lake in order to study the transfer law of solid and liquid phases in the dissolving and driving process and to design the optimal injection/abstraction strategy for dissolving and capturing maximum Potassium/ Magnesium in the mining of salt deposits in Qarhan Salt Lake.展开更多
In 2001, the International Seabed Authority (ISBA) initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crust...In 2001, the International Seabed Authority (ISBA) initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area at its 7th session. Since then, the consideration of the Regulations has been mainly focused on the size of areas to be allocated for exploration and exploitation of the crusts. This paper, based on the investigation data and the analysis of the distribution characteristics of the crusts, suggests a model for determining the size of areas for exploration and exploitation of the crusts, taking into account various factors such as production scale, crust thickness and grade, mineable area proportion, recovery efficiency, exploration venture, and so on. Through the modeling, the paper suggests that the exploration area (the area covered by each application for approval of a plan of work for exploration of cobalt-rich crusts) shall be 4 856 km2 and the exploitation area (the mine site area) shall be 1 214 km2, for 20 years of 1 million wet tonnes annual production.展开更多
China has nearly a hundred mining cities derived from mining development.While mining development has brought about immense achievements in a city’s economic construction,it has also resulted in different levels of d...China has nearly a hundred mining cities derived from mining development.While mining development has brought about immense achievements in a city’s economic construction,it has also resulted in different levels of damage to the eco-environment of the mining city,leaving behind a lot of subsided wasteland and heavily confining the sustainable development and transformation there.How to restore and exploit the land and eco-environment disrupted by mining development in an effective way,therefore,has become a pressing challenge that Chinese mining cities are facing.In this paper,the planning and construction of Nanhu Eco-city in the suburb of Tangshan City is analyzed as an example.After characterizing the coal-mining subsided lands in Kailuan Tangshan Mine originated in different periods and under different geological mining conditions and evaluating their safety level,the authors try to demonstrate how eco-restoration and comprehensive land exploitation should be implemented by making the best use of available local resources to achieve "economy-society-environment" sustainability and coexistence in a mining city.展开更多
CO_(2) can be used as an alternative injectant to exploit geothermal energy from depleted high-temperature gas reservoirs due to its high mobility and unique thermal properties.However,there has been a lack of systema...CO_(2) can be used as an alternative injectant to exploit geothermal energy from depleted high-temperature gas reservoirs due to its high mobility and unique thermal properties.However,there has been a lack of systematic analysis on the heat mining mechanism and performance of CO_(2),as well as the problems that may occur during geothermal energy exploitation at specific gas reservoir conditions.In this paper,a base numerical simulation model of a typical depleted high-temperature gas reservoir was established to simulate the geothermal energy exploitation processes via recycling CO_(2) and water,with a view to investigate whether and/or at which conditions CO_(2) is more suitable than water for geothermal energy exploitation.The problems that may occur during the CO_(2)-based geothermal energy exploitation were also analyzed along with proposed feasible solutions.The results indicate that,for a depleted low-permeability gas reservoir with dimensions of 1000 m×500 m×50 m and temperature of 150℃ using a single injection-production well group for 40 years of operation,the heat mining rate of CO_(2) can be up to 3.8 MW at a circulation flow rate of 18 kg s^(-1)due to its high mobility along with the flow path in the gas reservoir,while the heat mining rate of water is only about 2 MW due to limitations on the injectivity and mobility.The reservoir physical property and injection-production scheme have some effects on the heat mining rate,but CO_(2)always has better performance than water at most reservoir and operation conditions,even under a high water saturation.The main problems for CO_(2) circulation are wellbore corrosion and salt precipitation that can occur when the reservoir has high water saturation and high salinity,in which serious salt precipitation can reduce formation permeability and result in a decline of CO_(2) heat mining rate (e.g.up to 24%reduction).It is proposed to apply a low-salinity water slug before CO_(2)injection to reduce the damage caused by salt precipitation.For high-permeability gas reservoirs with high water saturation and high salinity,the superiority of CO_(2) as a heat transmission fluid becomes obscure and water injection is recommended.展开更多
Exploitation technology of pressure relief coalbed methane in vertical surface wells is a new method for exploration of gas and coalbed methane exploitation in mining areas with high concentrations of gas, where tecto...Exploitation technology of pressure relief coalbed methane in vertical surface wells is a new method for exploration of gas and coalbed methane exploitation in mining areas with high concentrations of gas, where tectonic coal developed. Studies on vertical surface well technology in the Huainan Coal Mining area play a role in demonstration in the use of clean, new energy resources, preventing and reducing coal mine gas accidents and protecting the environment. Based on the practice of gas drainage engineering of pressure relief coalbed methane in vertical surface wells and combined with relative geological and exploration en- gineering theories, the design principles of design and structure of wells of pressure relief coalbed methane in vertical surface wells are studied. The effects of extraction and their causes are discussed and the impact of geological conditions on gas production of the vertical surface wells are analyzed. The results indicate that in mining areas with high concentrations of gas, where tectonic coal developed, a success rate of pressure relief coalbed methane in surface vertical well is high and single well production usually great. But deformation due to coal exploitation could damage boreholes and cause breaks in the connection between aquifers and bore-holes, which could induce a decrease, even a complete halt in gas production of a single well. The design of well site location and wellbore configuration are the key for technology. The development of the geological conditions for coalbed methane have a significant effect on gas production of coalbed methane wells.展开更多
Coalbed methane(CBM)drilling and completion technologies(DCTs)are signifcant basis for achieving efcient CBM exploration and exploitation.Characteristics of CBM reservoirs vary in diferent regions around the world,the...Coalbed methane(CBM)drilling and completion technologies(DCTs)are signifcant basis for achieving efcient CBM exploration and exploitation.Characteristics of CBM reservoirs vary in diferent regions around the world,thereby,it is crucial to develop,select and apply the optimum DCTs for each diferent CBM reservoir.This paper frstly reviews the development history of CBM DCTs throughout worldwide and clarifes its overall development tendency.Secondly,diferent well types and its characteristics of CBM exploitation are summarized,and main application scopes of these well types are also discussed.Then,the key technologies of CBM drilling(directional drilling tools,measurement while drilling,geo-steering drilling,magnetic guidance drilling,underbalanced drilling and drilling fuids),and the key technologies of CBM completion(open-hole,cavity and under-ream completion,cased-hole completion,screen pipe completion and horizontal well completion)are summarized and analyzed,it is found that safe,economic and efcient development of CBM is inseparable from the support of advanced technologies.Finally,based on the current status of CBM development,the achievements,existing challenges and future prospects are summarized and discussed from the perspective of CBM DCTs.展开更多
Multifactorial correlation analysis is a new method used to predict the land subsidence caused by groundwater exploitation This article introduces and applies the method to establish the function of the surface settle...Multifactorial correlation analysis is a new method used to predict the land subsidence caused by groundwater exploitation This article introduces and applies the method to establish the function of the surface settlement rate (Vs) and the function of the time-dependent surface settlement (St) caused by groundwater exploitation, based on data acquired at three land subsidence monitoring stations in the Hanoi area of Vietnam. Comparison with actual monitoring data indicates that the prediction results are relatively close to the monitoring data. From this, we conclude that multifactorial correlation analysis is a reliable method and can be used to predict future land subsidence caused by groundwater exploitation in Hanoi.展开更多
基金This work was funded by multiple scientific research programs,including Evaluation and Optimal Target Selection of Deep Geothermal Resources in the Igneous Province in South China(No.:2019YFC0604903)Analysis and Geothermal Reservoir Stimulation Methods of Deep High-temperature Geothermal Systems in East China(No.:2021YFA0716004)of the National Key Research and Development Program of China+1 种基金a project entitled Deep Geological Processes and Resource Effects of Basins(No.:U20B6001)of the Joint Fund Program of the National Natural Science Foundation of China and Sinopeca project entitled Siting and Target Evaluation of Deep Geothermal Resources in Key Areas of Southeastern China(No.:P20041-1)of the Sinopec Science and Technology Research Program.
文摘The Maichen Sag in the south-central part of the Beibuwan Basin is abundant in geothermal resources that have not been widely exploited and utilized due to inadequate research on it.This study evaluated the geothermal resources in the Maichen Sag based on the regional geological setting and geothermal conditions.Grid units for assessment and a geological model for areas with geothermal resources were established using spatial analysis techniques.The spatial distribution models of the physical and thermophysical properties of the geothermal reservoirs were also built using the Kriging interpolation method.Based on the terrestrial heat flow distribution in the target areas,the spatial distribution of the geo-temperature field through the inversion under the constraints of the temperature data from boreholes were predicted.Factors such as deep geo-temperature,thermophysical properties of rocks,and terrestrial heat flow values,were integrated into this quantitative evaluation of geothermal resources through the geological modeling-based volume method and the geothermal reservoir engineering-based numerical simulation method.The results show that the Maichen Sag has favorable heat source conditions with intersected,deep-rooted faults and widely developed Upper Paleozoic fissured granite geothermal reservoirs.The northern outer slope zone at a burial depth of 3‒5 km on the tectonic plane of the basement in the sag is suggested to be a potential target area,where,as calculated using the volume method,is likely to be the home to the total geothermal resources of 80.4×10^(9)GJ(i.e.,2.75×10^(9)tonnes of coal equivalent(tce))in the bedrock geothermal reservoirs at a burial depth of 3‒6 km.The geotemperature of 172‒201℃at a formation depth of 5 km in the sag also indicates that the deep geothermal resources are of high value for exploitation.
基金Supported by the Planned Project for the Innovation and Entrepreneurship Training of College Students in China~~
文摘The insect is the animal protein feed resource potential, the rapid repro- duction, large quantity, high protein content, and most species of insects can be used as livestock feed utilization, development of insect as feed resources, to pro- mote the development of China's animal husbandry and feed industry, has important significance.
文摘Rural tourism, i.e., agrotourism, is the newly-exploited tourism product[1] with agricultural production, rustic view, rural life and rural custom as the main carrier and with agriculture and countryside as the tourism resources. Zhenjiang City is in possession of adequate source markets, abundant rural tourism resources, good tourist ecological environment and profound culture. The pleasant ecological environment and charming rural scenery provide the development of rural tourism in Zhenjiang with exceptional advantages. The exploitation of rural tourism not only promotes the exploitation and development of agricultural tourism in Zhenjiang, but also improves the structure of tourism product, simulating the healthy development of rural economy. Through the analysis of the exploitation advantage of the rural tourism resources in Zhenjiang, the author analyzed the exploitation situation and existing problems of the rural tourism resources in Zhenjiang. The author considered that the rural tourism development in Zhenjiang was lack of unified planning; the cultural content of tourism product was low; the development depth was not enough; the construction of infrastructure was lagging behind; and meanwhile, it was lacking of funding, tourism program and advertising promotion. In the light of the above deficiencies, a series of countermeasures of rural tourism exploitation was put forward, that is, to complete the exploitation planning of the rural tourism resources, promoting the cultural taste of the rural tourism product; to enhance the publicity of the rural tourism, highlighting the brand feature of local tourism and creating high-quality product; to conduct standard management, strengthening the training of tourism management personnel.
文摘This study aimed to make an orientation for the development of Zhenjiang Pearl S.Buck tourism products.According to the spatial structure styles of tourism products,this paper discussed the exploitation of Zhenjiang Pearl S.Buck tourism products from the perspective of spot products,linear products and network products.It expanded the Pearl S.Buck research to tourism science field and put forward some ideas of promoting the comprehensive benefits of Pearl S.Buck tourism resource as well as the exploitation of similar tourism products.
基金Supported by(First batch of)Scientific Research Program of Sichuan Academy of Higher Education(2007No.33)Key Project(2008)of Sichuan Provincial Department of Education:Study on the Industrial Cluster in Less-developed Areas(08SA047)~~
文摘Natural environment of Hailuogou Scenic Area(Conch Gully)was introduced,and it was pointed out that tourist resources in the study area showed gradient differentiation along the vertical height.In view of such gradient differentiation,resource contents and characteristics of its cultural heritages zone,geothermal resources zone,forest vegetation zone,and glacial resources zone were respectively analyzed.Based on the gradient differentiation of tourist resources in Hailuogou Scenic Area,suggestions were given for its further tourism development,and it was stressed that brand effects of the attractions should be enhanced,infrastructure construction and maintenance of newly-explored scenic spots should be improved,and more efforts should be devoted to explore disastrous landform resources.This research is of practical significance for studying spatial differentiation and evolution mechanism of tourist resources in mountainous areas in western China,and also provides scientific support for the exploration of tourist resources in mountainous areas.
基金Supported by Natural Science Foundation of China (40961008)~~
文摘The paper had introduced geographic causes and types of hot springs, illustrated its disease-treating function and displayed its great vitality and widespread development prospect as tourist resources. By taking Shawan Hot Spring in Xinjiang for example, the paper had analyzed its natural condition, hot springs and tourist economic development. And then, quantitative and qualitative analysis had been conducted on the quality of water environment resources in the research area. It had analyzed reasons for degeneration of water environment and studied exploitation and sustainable development of hot springs. It was considered that environment especially water environment quality had decreased since hot spring tourism development. In order to achieve sustainable development of hot springs and promotion of local tourism, it must be guided by environment treatment, and some strategies for sustainable development of hot springs had been proposed.
文摘The society of today often likes to brand itself as modem, advanced, civilized, or a society of positive changes. However, it is a fact that the world is confronted with huge contradictions that oppose such qualifications. Obviously, one of the most striking and almost unbelievable realities tells us about inhumane and uncivilized actions of child exploitation in "entrepreneurial" purposes in the widest range of exploitation and abuse. Current period of economic crisis tells us even more about the rising crisis of moral, which is, in statistical terms, confirmed by a rising number of exploited children in a global framework, and even in some national frameworks as well. With that, some positive results about the diminishing number of exploited children are devaluated. The question is what are the "limits" of such behavior of groups, organizations, and individuals whose behavior is, obviously, tolerated in the frameworks of certain national economies. Does this behavior have clarity as a part of modem society? Or, even more severe, for how long can we as a society close our eyes in front of such facts? Do we even have the right? In this paper, the authors strive towards focusing and objectifying the global problem of exploitation and abuse of children in "entrepreneurial" purposes, primarily with the purpose of updating all parts of the society of this paradox and the need of raising the awareness and teaching all relevant factors--from institutions to individuals, with the purpose of resolving and more neutralize the equivalents of this uncivilized and non-entrepreneurial "phenomenon", as well as approaching the same in the framework of different actions with broadest measures possible and with all disposable assets.
基金Supported by the Natural Science Foundation of Shanxi (2013021029-2), the 12th Five-Year Science and Technology Support Program (2012BAB 13B04), the Research Fund for the Doctoral Program of Higher Education of China (20111402120004)
文摘On the basis of considering the heterogeneity and using the finite element numerical simulation, this thesis investi- gates the damage of the roof and coal as well as the failure of evolutionary process during the re-exploitation of the residual coal. According to the analysis of the damage field, stress field and the failure process, it explores the damage evolution, stress distribution laws and the damage models. Besides, this thesis puts forward the idea of penetrating and establishing drilling steels aimed at solving the problem of wall carving and roof fall, meanwhile this suggestion accomplishes the successful appli- cation effect in the testing ground. This thesis demonstrates that the re-exploitation of the residual coal can be carried out and the safe production can be ensured by adopting some measures. What's more, the research result provides the theoretical and practical experience for the re-exploitation of the residual coal in the similar conditions.
文摘Groundwater over-exploitation is a major problem in groundwater development, utilization and protection. At present, the area of shallow groundwater over-exploitation in the High-tech Zone is 76 km^(2). In this study, the system and mechanism construction, engineering measure construction, and control effect of national comprehensive control project of groundwater over-exploitation areas in the High-tech Zone in 2020 were evaluated, and the comprehensive control of groundwater over-exploitation in the High-tech Zone in the year was summarized to provide effective basis for the continuous implementation of comprehensive control of groundwater over-exploitation. At the same time, the water-saving and exploitation reduction effect and generalizability of different measures were studied to provide useful reference for other over-exploitation areas.
文摘America had been attempting to annex Canadian West and posed a threat to the security of the fledgling country. Therefore the antipathy towards America as well as independent-nation complex of Canadians drove Canadian government to incorporate the west exploitation into the national strategy of creating an independent country. Canadian west exploitation thus took on some distinctiveness.
文摘Calculated in terms of surface runoff plus irrepeated groundwater, there is about 8. 67 ×1010m3 of total available water resources in the inland river basins of arid Northwest China. Water resources is the decisive factor for survival of oases and human being. But there have arisen several aspects of Serious eco-environment problems resulted from irrational exploitation and utilization. From now on, the development and utilization of water not only requires to promote regional economy, but also needs to protect and improve the environment based on their potential. Sustainable utilization needs to broaden new sources and saving water at first. Then three measures are recommended.
基金the National Natural Science Foundation of China
文摘Firstly, the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer (salt deposit) in Qarhan Salt Lake was studied by using the Pitzer theory. The concept of macroscopic solubility product and its relation with accumulated ore dissolving ratio were presented, which are used in the numerical model of dissolving and driving exploitation of potassium salt in Qarhan Salt Lake. And secondly, with a model forming idea of transport model for reacting solutes in the multi-component fresh groundwater system in porous media being a reference, a two-dimensional transport model coupled with a series of chemical reactions in a multi-component brine porous system (salt deposits) was developed by using the Pitzer theory. Meanwhile, the model was applied to model potassium/magnesium transport in Qarhan Salt Lake in order to study the transfer law of solid and liquid phases in the dissolving and driving process and to design the optimal injection/abstraction strategy for dissolving and capturing maximum Potassium/ Magnesium in the mining of salt deposits in Qarhan Salt Lake.
基金China International Seabed Area R & D Program under contract No.DYXM-115-01-1
文摘In 2001, the International Seabed Authority (ISBA) initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area at its 7th session. Since then, the consideration of the Regulations has been mainly focused on the size of areas to be allocated for exploration and exploitation of the crusts. This paper, based on the investigation data and the analysis of the distribution characteristics of the crusts, suggests a model for determining the size of areas for exploration and exploitation of the crusts, taking into account various factors such as production scale, crust thickness and grade, mineable area proportion, recovery efficiency, exploration venture, and so on. Through the modeling, the paper suggests that the exploration area (the area covered by each application for approval of a plan of work for exploration of cobalt-rich crusts) shall be 4 856 km2 and the exploitation area (the mine site area) shall be 1 214 km2, for 20 years of 1 million wet tonnes annual production.
文摘China has nearly a hundred mining cities derived from mining development.While mining development has brought about immense achievements in a city’s economic construction,it has also resulted in different levels of damage to the eco-environment of the mining city,leaving behind a lot of subsided wasteland and heavily confining the sustainable development and transformation there.How to restore and exploit the land and eco-environment disrupted by mining development in an effective way,therefore,has become a pressing challenge that Chinese mining cities are facing.In this paper,the planning and construction of Nanhu Eco-city in the suburb of Tangshan City is analyzed as an example.After characterizing the coal-mining subsided lands in Kailuan Tangshan Mine originated in different periods and under different geological mining conditions and evaluating their safety level,the authors try to demonstrate how eco-restoration and comprehensive land exploitation should be implemented by making the best use of available local resources to achieve "economy-society-environment" sustainability and coexistence in a mining city.
基金This research was financially supported by the National Natural Science Foundation of China(Grant No.51674282)the National Key R&D Programs of China(Grant No.2019YFB1504201,2019YFB1504203,and 2019YFB1504204)+2 种基金the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant No.CUGGC09 and CUG200637)the Open Project Program of Key Laboratory of Groundwater Resources and Environment(Jilin University),Ministry of Education(Grant No.202005001KF)Opening Fund of Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)),Ministry of Education(Grant No.19CX05005A-201)。
文摘CO_(2) can be used as an alternative injectant to exploit geothermal energy from depleted high-temperature gas reservoirs due to its high mobility and unique thermal properties.However,there has been a lack of systematic analysis on the heat mining mechanism and performance of CO_(2),as well as the problems that may occur during geothermal energy exploitation at specific gas reservoir conditions.In this paper,a base numerical simulation model of a typical depleted high-temperature gas reservoir was established to simulate the geothermal energy exploitation processes via recycling CO_(2) and water,with a view to investigate whether and/or at which conditions CO_(2) is more suitable than water for geothermal energy exploitation.The problems that may occur during the CO_(2)-based geothermal energy exploitation were also analyzed along with proposed feasible solutions.The results indicate that,for a depleted low-permeability gas reservoir with dimensions of 1000 m×500 m×50 m and temperature of 150℃ using a single injection-production well group for 40 years of operation,the heat mining rate of CO_(2) can be up to 3.8 MW at a circulation flow rate of 18 kg s^(-1)due to its high mobility along with the flow path in the gas reservoir,while the heat mining rate of water is only about 2 MW due to limitations on the injectivity and mobility.The reservoir physical property and injection-production scheme have some effects on the heat mining rate,but CO_(2)always has better performance than water at most reservoir and operation conditions,even under a high water saturation.The main problems for CO_(2) circulation are wellbore corrosion and salt precipitation that can occur when the reservoir has high water saturation and high salinity,in which serious salt precipitation can reduce formation permeability and result in a decline of CO_(2) heat mining rate (e.g.up to 24%reduction).It is proposed to apply a low-salinity water slug before CO_(2)injection to reduce the damage caused by salt precipitation.For high-permeability gas reservoirs with high water saturation and high salinity,the superiority of CO_(2) as a heat transmission fluid becomes obscure and water injection is recommended.
基金Projects 2007AA06Z220 supported by the Hi-tech Research and Development Program of China307014 by the Key Science and Technology Program of the Ministry of Education
文摘Exploitation technology of pressure relief coalbed methane in vertical surface wells is a new method for exploration of gas and coalbed methane exploitation in mining areas with high concentrations of gas, where tectonic coal developed. Studies on vertical surface well technology in the Huainan Coal Mining area play a role in demonstration in the use of clean, new energy resources, preventing and reducing coal mine gas accidents and protecting the environment. Based on the practice of gas drainage engineering of pressure relief coalbed methane in vertical surface wells and combined with relative geological and exploration en- gineering theories, the design principles of design and structure of wells of pressure relief coalbed methane in vertical surface wells are studied. The effects of extraction and their causes are discussed and the impact of geological conditions on gas production of the vertical surface wells are analyzed. The results indicate that in mining areas with high concentrations of gas, where tectonic coal developed, a success rate of pressure relief coalbed methane in surface vertical well is high and single well production usually great. But deformation due to coal exploitation could damage boreholes and cause breaks in the connection between aquifers and bore-holes, which could induce a decrease, even a complete halt in gas production of a single well. The design of well site location and wellbore configuration are the key for technology. The development of the geological conditions for coalbed methane have a significant effect on gas production of coalbed methane wells.
基金supported by the Youth Scientific and Technological Innovation Team Foundation of Southwest Petroleum University(2019CXTD09)the Program of Introducing Talents of Discipline to Chinese Universities(111 Plan)(D18016).
文摘Coalbed methane(CBM)drilling and completion technologies(DCTs)are signifcant basis for achieving efcient CBM exploration and exploitation.Characteristics of CBM reservoirs vary in diferent regions around the world,thereby,it is crucial to develop,select and apply the optimum DCTs for each diferent CBM reservoir.This paper frstly reviews the development history of CBM DCTs throughout worldwide and clarifes its overall development tendency.Secondly,diferent well types and its characteristics of CBM exploitation are summarized,and main application scopes of these well types are also discussed.Then,the key technologies of CBM drilling(directional drilling tools,measurement while drilling,geo-steering drilling,magnetic guidance drilling,underbalanced drilling and drilling fuids),and the key technologies of CBM completion(open-hole,cavity and under-ream completion,cased-hole completion,screen pipe completion and horizontal well completion)are summarized and analyzed,it is found that safe,economic and efcient development of CBM is inseparable from the support of advanced technologies.Finally,based on the current status of CBM development,the achievements,existing challenges and future prospects are summarized and discussed from the perspective of CBM DCTs.
基金supported by Vietnam National Funds of Education and Training
文摘Multifactorial correlation analysis is a new method used to predict the land subsidence caused by groundwater exploitation This article introduces and applies the method to establish the function of the surface settlement rate (Vs) and the function of the time-dependent surface settlement (St) caused by groundwater exploitation, based on data acquired at three land subsidence monitoring stations in the Hanoi area of Vietnam. Comparison with actual monitoring data indicates that the prediction results are relatively close to the monitoring data. From this, we conclude that multifactorial correlation analysis is a reliable method and can be used to predict future land subsidence caused by groundwater exploitation in Hanoi.