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
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
Coal exploitation inevitably damages the natural ecological environment through large scale underground exploitation which exhausts the surrounding areas and is the cause of surface subsidence and cracks. These types ...Coal exploitation inevitably damages the natural ecological environment through large scale underground exploitation which exhausts the surrounding areas and is the cause of surface subsidence and cracks. These types of damage seriously lower the underground water table. Deterioration of the environment has certainly an impact on and limits growth of vegetation,which is a very important indicator of a healthy ecological system. Dynamically monitoring vegetation growth under coal exploitation stress by remote sensing technology provides advantages such as large scale coverage,high accuracy and abundant information. A scatter plot was built by a TM (Thematic Mapper) infrared and red bands. A detailed analysis of the distributional characteristics of vegetation pixels has been carried out. Results show that vegetation pixels are affected by soil background pixels,while the distribution of soil pixels presents a linear pattern. Soil line equations were obtained mainly by linear regression. A new band,reflecting vegetation growth,has been obtained based on the elimination of the soil background. A grading of vegetation images was extracted by means of a density slice method. Our analysis indicates that before the exploitation of the Bulianta coal mining area,vegetation growth had gradually reduced; especially intermediate growth vegetation had been transformed into low vegetation. It may have been caused by the deterioration of the brittle environment in the western part of the mining area. All the same,after the start of coal production,vegetation growth has gradually improved,probably due to large scale aerial seeding. Remote sensing interpretation results proved to be consistent with the actual situation on the ground. From our research results we can not conclude that coal exploitation stress has no impact on the growth of vegetation. More de-tailed research on vegetation growth needs to be analyzed.展开更多
In the current data-intensive era, the traditional hands-on method of conducting scientific research by exploring related publications to generate a testable hypothesis is well on its way of becoming obsolete within j...In the current data-intensive era, the traditional hands-on method of conducting scientific research by exploring related publications to generate a testable hypothesis is well on its way of becoming obsolete within just a year or two. Analyzing the literature and data to automatically generate a hypothesis might become the de facto approach to inform the core research efforts of those trying to master the exponentially rapid expansion of publications and datasets. Here, viewpoints are provided and discussed to help the understanding of challenges of data-driven discovery.展开更多
Coal and coalbed methane(CBM)coordinated exploitation is a key technology for the safe exploitation of both resources.However,existing studies lack the quantification and evaluation of the degree of coordination betwe...Coal and coalbed methane(CBM)coordinated exploitation is a key technology for the safe exploitation of both resources.However,existing studies lack the quantification and evaluation of the degree of coordination between coal mining and coalbed methane extraction.In this study,the concept of coal and coalbed methane coupling coordinated exploitation was proposed,and the corresponding evaluation model was established using the Bayesian principle.On this basis,the objective function of coal and coalbed methane coordinated exploitation deployment was established,and the optimal deployment was determined through a cuckoo search.The results show that clarifying the coupling coordinated level of coal and coalbed methane resource exploitation in coal mines is conducive to adjusting the deployment plan in advance.The case study results show that the evaluation and intelligent deployment method proposed in this paper can effectively evaluate the coupling coordinated level of coal and coalbed methane resource exploitation and intelligently optimize the deployment of coal mine operations.The optimization results demonstrate that the safe and efficient exploitation of coal and CBM resources is promoted,and coal mining and coalbed methane extraction processes show greater cooperation.The observations and findings of this study provide a critical reference for coal mine resource exploitation in the future.展开更多
Geological environment effects caused by the control of groundwater exploitation in Jiangyin city are discussed thoroughly, including the dynamic variation of groundwater levels and quality and the development of land...Geological environment effects caused by the control of groundwater exploitation in Jiangyin city are discussed thoroughly, including the dynamic variation of groundwater levels and quality and the development of land sub-sidence and ground fissures. According to the dynamic characteristics of groundwater levels, some advice about groundwater exploitation is offered. Our research will provide a basis for using groundwater resources and the preven- tion of geological disasters in Jiangyin city and the Suzhou-Wuxi-Changzhou area. The following results are deduced from our research. First, groundwater levels vary with the exploitation of groundwater in Jiangyin city and are affected by hydrogeological conditions. The groundwater levels remained rather stable before and after the implementation of control of groundwater exploitation in the northwest of Jiangyin city along the Yangtze River. A suitable level of exploitation should be allowed. In the southeast, the speed of recovery of the groundwater level has been rather rapid after the control of exploitation. We conclude that groundwater might be exploited locally after the groundwater level has recovered. In the southwest, the speed of recovery of the groundwater level is rather slow and exploitation of ground-water should be prohibited. Second, groundwater quality is stable in Jiangyin city and the contents of the main chemical indices of groundwater varied only slightly before and after the control of exploitation. Third, after controlling the exploitation, the speed of land subsidence has clearly slowed down and the development of ground fissures has been controlled effectively.展开更多
A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in t...A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in the two regions due to basic differences in nature of the forest and in the degree and persistence of exploitive pressures. After a century since unregulated exploitation, West Virginia forests are well on the road to management for sustainability and conservation. Shaanxi's recovery from overuse and unregulated exploitation is less certain; forests are still in the early phases of ecological recovery there. Full recovery to a period of sustainability will take a century or longer. Suggestions are made for measures needed to enhance the forest recovery. Keywords Forests - Shaanxi - West Virginia - Central China - Forest exploitation - Recovery CLC number S754 Document code A Article ID 1007-662X(2004)01-0049-06 Foundation item: The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2002–2004) and Shaanxi Provincial Foreign Expert Bureau (2003).Biography: Jack E. Coster (1935-), male, professor of West Virginia University, Morgantown, West Virginia. U.S.A.Responsible editor: Song Funan展开更多
Division arithmetic and generalized exploiting modification direction （DA-GEMD） method has perfect efficiency in data-hiding. However, there exist some weaknesses in DA-GEMD. Because the benchmarks are their median ...Division arithmetic and generalized exploiting modification direction （DA-GEMD） method has perfect efficiency in data-hiding. However, there exist some weaknesses in DA-GEMD. Because the benchmarks are their median of nine pixels in each block of cover-image, it will give a hint for the attacker to hack the stego-image. In the paper, we utilize the Sudoku table to randomize the benchmark for each 3×3 block of cover-image. It will mix up the pixels in each image block and prevent the secret information from being extracted. The proposed method still keeps the original efficiency as DA-GEMD while promoting the security for data-hiding.展开更多
With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry o...With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry on the regional economy has also become a main focus.Shale gas’exploration and extraction may have positive spillover effects on other sectors,resulting in population growth and job creation.However,negative spillover effects can occur through rising local goods prices and its adverse effects on the local quality of life,which in turn could harm population growth and employment.By using the synthetic control method,we investigates the shale gas fields in Chongqing to reveal the relationship between population growth,employment and shale gas development in Fuling,Nanchuan and Wulong districts.Our results indicate that due to the development of the shale gas industry,the number of urban non-private sector employees in three districts and counties has decreased.From 2017 to 2018,this decline had gradually weakened and the population growth had been negatively affected.展开更多
The additional sparse prior of images has been the subject of much research in problems of sparse-view computed tomography（CT） reconstruction. A method employing the image gradient sparsity is often used to reduce t...The additional sparse prior of images has been the subject of much research in problems of sparse-view computed tomography（CT） reconstruction. A method employing the image gradient sparsity is often used to reduce the sampling rate and is shown to remove the unwanted artifacts while preserve sharp edges, but may cause blocky or patchy artifacts.To eliminate this drawback, we propose a novel sparsity exploitation-based model for CT image reconstruction. In the presented model, the sparse representation and sparsity exploitation of both gradient and nonlocal gradient are investigated.The new model is shown to offer the potential for better results by introducing a similarity prior information of the image structure. Then, an effective alternating direction minimization algorithm is developed to optimize the objective function with a robust convergence result. Qualitative and quantitative evaluations have been carried out both on the simulation and real data in terms of accuracy and resolution properties. The results indicate that the proposed method can be applied for achieving better image-quality potential with the theoretically expected detailed feature preservation.展开更多
There have been few studies on the hydropower exploitation plan for sections beyond the Inga hydropower project(HPP)in the lower reaches of the Congo River.Based on topographic and hydrological data of the basin,the e...There have been few studies on the hydropower exploitation plan for sections beyond the Inga hydropower project(HPP)in the lower reaches of the Congo River.Based on topographic and hydrological data of the basin,the exploitation plan for the lower reaches of the Congo River is herein studied.The preliminary proposal involves exploitation using three-cascade hydropower stations.The Grand Inga HPP is the core of the mega hydropower base.The full supply level(FSL)of the reservoir,installed capacity,and regulation performance of the Grand Inga HPP are studied in detail.The main advantages and disadvantages of the high and low dam schemes of the Grand Inga Hydropower Project are compared,in addition to their effects on the overall development of the hydropower base.Moreover,the installed capacity is optimized based on the load characteristics.Based on simulation of cascade hydropower operation and comprehensive analysis,the project scale and implementation sequence is proposed.The influence of hydropower on socio-economic development,energy supply,and emission reduction is analyzed.Finally,the optimal exploitation scheme of the mega hydropower base for the lower reaches of the Congo River is proposed.展开更多
Through analyzing environment geological effect of groundwater in detail, the authors hold that the groundwater exploitation is excessive in Linfen City. A regional depression cone has been formed in the civic center;...Through analyzing environment geological effect of groundwater in detail, the authors hold that the groundwater exploitation is excessive in Linfen City. A regional depression cone has been formed in the civic center; The subsidence scale keeps increasing, and five developed earth fissure hazards zones have been formed. This hinders the sustainable economic development of Linfen severely. Large scale observation net of groundwater should be established to dynamically monitor the ground water, ensuring a rational exploitation.展开更多
With the increase of the clock frequency and silicon integration, power aware computing has become a critical concern in the design of the embedded processor and system-on-chip （SoC）. Dynamic voltage scaling （DVS）...With the increase of the clock frequency and silicon integration, power aware computing has become a critical concern in the design of the embedded processor and system-on-chip （SoC）. Dynamic voltage scaling （DVS） is an effective method for low-power designs. However, traditional DVS methods have two deficiencies. First, they have a conservative safety margin which is not necessary for most of the time. Second, they are exclusively concerned with the critical stage and ignore the significant potential free slack time of the noncritical stage. These factors lead to a large amount of power waste. In this paper, a novel pipeline structure with ultra-low power consumption is proposed. It cuts off the safety margin and takes use of the noncritical stages at the same time. A prototype pipeline is designed in 0.13 μm technology and analyzed. The result shows that a large amount of energy can be saved by using this structure. Compared with the fixed voltage case, 50% of the energy can be saved, and with respect to the traditional adaptive voltage scaling design, 37.8% of the energy can be saved.展开更多
Based on affirming the tremendous benefits that water resources of rivers can provide in their exploitation, main environmental problems and their countermeasures have been proposed and analyzed in this paper. It is a...Based on affirming the tremendous benefits that water resources of rivers can provide in their exploitation, main environmental problems and their countermeasures have been proposed and analyzed in this paper. It is argued that multiple measures should be applied to solving those problems by simultaneously carrying out engineering measures, scientific research and also programs to cultivate the society’s awareness, aimed at a sustainable development strategy for exploiting water resources.展开更多
The problem of determining the pass on heat coefficient of the water-bearing stratum in geothermal reservior exploitation is investigated using the regularised output-least-square formulation. The regularity propertie...The problem of determining the pass on heat coefficient of the water-bearing stratum in geothermal reservior exploitation is investigated using the regularised output-least-square formulation. The regularity properties of the coefficient is obtained.展开更多
In our country,the present exploitation of ocean renewable energy mainly concentrates on the tidal power,wave can,and the trend of the development of salt difference energy and temperature difference energy are still ...In our country,the present exploitation of ocean renewable energy mainly concentrates on the tidal power,wave can,and the trend of the development of salt difference energy and temperature difference energy are still locating in the state of research and testing. The exploitation of tidal current energy and wave energy has made great progress recently. Although these achievements are quite comforting,compared with other sorts of renewable energy,the interrelated research on ocean renewable energy is still defective. After investigating correlative data,the passage lists several reasons to explain current status. This article focuses on analyzing feasibility and necessity of ocean energy development in China,as well as introducing foreign ocean renewable energy development which is summarized into some experience. Through a careful study on these systems,it puts forward and demonstrates five ocean renewable energy exploitation in Chinese legal system:ocean renewable energy exploitation integrated management system,ocean renewable energy market financing system and so on. It also discusses how to realize specific implementation of these schemes and their feasibility.展开更多
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.
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Project 2003AA322040 supported by the National High Technology Research and Development Program of China
文摘Coal exploitation inevitably damages the natural ecological environment through large scale underground exploitation which exhausts the surrounding areas and is the cause of surface subsidence and cracks. These types of damage seriously lower the underground water table. Deterioration of the environment has certainly an impact on and limits growth of vegetation,which is a very important indicator of a healthy ecological system. Dynamically monitoring vegetation growth under coal exploitation stress by remote sensing technology provides advantages such as large scale coverage,high accuracy and abundant information. A scatter plot was built by a TM (Thematic Mapper) infrared and red bands. A detailed analysis of the distributional characteristics of vegetation pixels has been carried out. Results show that vegetation pixels are affected by soil background pixels,while the distribution of soil pixels presents a linear pattern. Soil line equations were obtained mainly by linear regression. A new band,reflecting vegetation growth,has been obtained based on the elimination of the soil background. A grading of vegetation images was extracted by means of a density slice method. Our analysis indicates that before the exploitation of the Bulianta coal mining area,vegetation growth had gradually reduced; especially intermediate growth vegetation had been transformed into low vegetation. It may have been caused by the deterioration of the brittle environment in the western part of the mining area. All the same,after the start of coal production,vegetation growth has gradually improved,probably due to large scale aerial seeding. Remote sensing interpretation results proved to be consistent with the actual situation on the ground. From our research results we can not conclude that coal exploitation stress has no impact on the growth of vegetation. More de-tailed research on vegetation growth needs to be analyzed.
文摘In the current data-intensive era, the traditional hands-on method of conducting scientific research by exploring related publications to generate a testable hypothesis is well on its way of becoming obsolete within just a year or two. Analyzing the literature and data to automatically generate a hypothesis might become the de facto approach to inform the core research efforts of those trying to master the exponentially rapid expansion of publications and datasets. Here, viewpoints are provided and discussed to help the understanding of challenges of data-driven discovery.
基金supported by the Natural Science Foundation of Chongqing,China(No.cstc2020jcyj-msxmX0836)the Fundamental Research Funds for the Central Universities(No.2020CDJ-LHZZ-002)the National Natural Science Foundation of China(No.52074041).
文摘Coal and coalbed methane(CBM)coordinated exploitation is a key technology for the safe exploitation of both resources.However,existing studies lack the quantification and evaluation of the degree of coordination between coal mining and coalbed methane extraction.In this study,the concept of coal and coalbed methane coupling coordinated exploitation was proposed,and the corresponding evaluation model was established using the Bayesian principle.On this basis,the objective function of coal and coalbed methane coordinated exploitation deployment was established,and the optimal deployment was determined through a cuckoo search.The results show that clarifying the coupling coordinated level of coal and coalbed methane resource exploitation in coal mines is conducive to adjusting the deployment plan in advance.The case study results show that the evaluation and intelligent deployment method proposed in this paper can effectively evaluate the coupling coordinated level of coal and coalbed methane resource exploitation and intelligently optimize the deployment of coal mine operations.The optimization results demonstrate that the safe and efficient exploitation of coal and CBM resources is promoted,and coal mining and coalbed methane extraction processes show greater cooperation.The observations and findings of this study provide a critical reference for coal mine resource exploitation in the future.
基金Projects 2002CB412702 supported by the Special Funds for Major State Basic Research Projects of China and KZCX2-YW-113the Special Funds ofResearch Innovation Projects of CAS
文摘Geological environment effects caused by the control of groundwater exploitation in Jiangyin city are discussed thoroughly, including the dynamic variation of groundwater levels and quality and the development of land sub-sidence and ground fissures. According to the dynamic characteristics of groundwater levels, some advice about groundwater exploitation is offered. Our research will provide a basis for using groundwater resources and the preven- tion of geological disasters in Jiangyin city and the Suzhou-Wuxi-Changzhou area. The following results are deduced from our research. First, groundwater levels vary with the exploitation of groundwater in Jiangyin city and are affected by hydrogeological conditions. The groundwater levels remained rather stable before and after the implementation of control of groundwater exploitation in the northwest of Jiangyin city along the Yangtze River. A suitable level of exploitation should be allowed. In the southeast, the speed of recovery of the groundwater level has been rather rapid after the control of exploitation. We conclude that groundwater might be exploited locally after the groundwater level has recovered. In the southwest, the speed of recovery of the groundwater level is rather slow and exploitation of ground-water should be prohibited. Second, groundwater quality is stable in Jiangyin city and the contents of the main chemical indices of groundwater varied only slightly before and after the control of exploitation. Third, after controlling the exploitation, the speed of land subsidence has clearly slowed down and the development of ground fissures has been controlled effectively.
基金The Scientific Research Foundation for the Returned Overseas Chinese Scholars State Education Ministry(2002-2004)and Shaanxi Provincial Foreign Expert Bureau (2003).
文摘A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in the two regions due to basic differences in nature of the forest and in the degree and persistence of exploitive pressures. After a century since unregulated exploitation, West Virginia forests are well on the road to management for sustainability and conservation. Shaanxi's recovery from overuse and unregulated exploitation is less certain; forests are still in the early phases of ecological recovery there. Full recovery to a period of sustainability will take a century or longer. Suggestions are made for measures needed to enhance the forest recovery. Keywords Forests - Shaanxi - West Virginia - Central China - Forest exploitation - Recovery CLC number S754 Document code A Article ID 1007-662X(2004)01-0049-06 Foundation item: The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2002–2004) and Shaanxi Provincial Foreign Expert Bureau (2003).Biography: Jack E. Coster (1935-), male, professor of West Virginia University, Morgantown, West Virginia. U.S.A.Responsible editor: Song Funan
文摘Division arithmetic and generalized exploiting modification direction （DA-GEMD） method has perfect efficiency in data-hiding. However, there exist some weaknesses in DA-GEMD. Because the benchmarks are their median of nine pixels in each block of cover-image, it will give a hint for the attacker to hack the stego-image. In the paper, we utilize the Sudoku table to randomize the benchmark for each 3×3 block of cover-image. It will mix up the pixels in each image block and prevent the secret information from being extracted. The proposed method still keeps the original efficiency as DA-GEMD while promoting the security for data-hiding.
基金supported by the Major Program of National Social Science Foundation,China(19ZDA083)National Natural Science Foundation,China(71603193 and 71974151)Teaching&Research Project of Wuhan University,China(1201-413200127)。
文摘With the maturity of horizontal drilling and hydraulic fracturing technologies,countries rich in shale gas have begun to promote the development of the shale gas industry.The impact of the booming shale gas industry on the regional economy has also become a main focus.Shale gas’exploration and extraction may have positive spillover effects on other sectors,resulting in population growth and job creation.However,negative spillover effects can occur through rising local goods prices and its adverse effects on the local quality of life,which in turn could harm population growth and employment.By using the synthetic control method,we investigates the shale gas fields in Chongqing to reveal the relationship between population growth,employment and shale gas development in Fuling,Nanchuan and Wulong districts.Our results indicate that due to the development of the shale gas industry,the number of urban non-private sector employees in three districts and counties has decreased.From 2017 to 2018,this decline had gradually weakened and the population growth had been negatively affected.
基金Project supported by the National Natural Science Foundation of China(Grant No.61372172)
文摘The additional sparse prior of images has been the subject of much research in problems of sparse-view computed tomography（CT） reconstruction. A method employing the image gradient sparsity is often used to reduce the sampling rate and is shown to remove the unwanted artifacts while preserve sharp edges, but may cause blocky or patchy artifacts.To eliminate this drawback, we propose a novel sparsity exploitation-based model for CT image reconstruction. In the presented model, the sparse representation and sparsity exploitation of both gradient and nonlocal gradient are investigated.The new model is shown to offer the potential for better results by introducing a similarity prior information of the image structure. Then, an effective alternating direction minimization algorithm is developed to optimize the objective function with a robust convergence result. Qualitative and quantitative evaluations have been carried out both on the simulation and real data in terms of accuracy and resolution properties. The results indicate that the proposed method can be applied for achieving better image-quality potential with the theoretically expected detailed feature preservation.
基金supported by the State Grid Corporation of China Science and Technology Project(Title:Study on Method and Evaluation Principle for the Cross-Continent Power Transmission Planning)。
文摘There have been few studies on the hydropower exploitation plan for sections beyond the Inga hydropower project(HPP)in the lower reaches of the Congo River.Based on topographic and hydrological data of the basin,the exploitation plan for the lower reaches of the Congo River is herein studied.The preliminary proposal involves exploitation using three-cascade hydropower stations.The Grand Inga HPP is the core of the mega hydropower base.The full supply level(FSL)of the reservoir,installed capacity,and regulation performance of the Grand Inga HPP are studied in detail.The main advantages and disadvantages of the high and low dam schemes of the Grand Inga Hydropower Project are compared,in addition to their effects on the overall development of the hydropower base.Moreover,the installed capacity is optimized based on the load characteristics.Based on simulation of cascade hydropower operation and comprehensive analysis,the project scale and implementation sequence is proposed.The influence of hydropower on socio-economic development,energy supply,and emission reduction is analyzed.Finally,the optimal exploitation scheme of the mega hydropower base for the lower reaches of the Congo River is proposed.
文摘Through analyzing environment geological effect of groundwater in detail, the authors hold that the groundwater exploitation is excessive in Linfen City. A regional depression cone has been formed in the civic center; The subsidence scale keeps increasing, and five developed earth fissure hazards zones have been formed. This hinders the sustainable economic development of Linfen severely. Large scale observation net of groundwater should be established to dynamically monitor the ground water, ensuring a rational exploitation.
基金supported by the Important National S&T Special Project of China under Grant No.2011ZX01034-002-001-2the Fundamental Research Funds for the Central Universities under Grant No.ZYGX2009J026
文摘With the increase of the clock frequency and silicon integration, power aware computing has become a critical concern in the design of the embedded processor and system-on-chip （SoC）. Dynamic voltage scaling （DVS） is an effective method for low-power designs. However, traditional DVS methods have two deficiencies. First, they have a conservative safety margin which is not necessary for most of the time. Second, they are exclusively concerned with the critical stage and ignore the significant potential free slack time of the noncritical stage. These factors lead to a large amount of power waste. In this paper, a novel pipeline structure with ultra-low power consumption is proposed. It cuts off the safety margin and takes use of the noncritical stages at the same time. A prototype pipeline is designed in 0.13 μm technology and analyzed. The result shows that a large amount of energy can be saved by using this structure. Compared with the fixed voltage case, 50% of the energy can be saved, and with respect to the traditional adaptive voltage scaling design, 37.8% of the energy can be saved.
文摘Based on affirming the tremendous benefits that water resources of rivers can provide in their exploitation, main environmental problems and their countermeasures have been proposed and analyzed in this paper. It is argued that multiple measures should be applied to solving those problems by simultaneously carrying out engineering measures, scientific research and also programs to cultivate the society’s awareness, aimed at a sustainable development strategy for exploiting water resources.
文摘The problem of determining the pass on heat coefficient of the water-bearing stratum in geothermal reservior exploitation is investigated using the regularised output-least-square formulation. The regularity properties of the coefficient is obtained.
文摘In our country,the present exploitation of ocean renewable energy mainly concentrates on the tidal power,wave can,and the trend of the development of salt difference energy and temperature difference energy are still locating in the state of research and testing. The exploitation of tidal current energy and wave energy has made great progress recently. Although these achievements are quite comforting,compared with other sorts of renewable energy,the interrelated research on ocean renewable energy is still defective. After investigating correlative data,the passage lists several reasons to explain current status. This article focuses on analyzing feasibility and necessity of ocean energy development in China,as well as introducing foreign ocean renewable energy development which is summarized into some experience. Through a careful study on these systems,it puts forward and demonstrates five ocean renewable energy exploitation in Chinese legal system:ocean renewable energy exploitation integrated management system,ocean renewable energy market financing system and so on. It also discusses how to realize specific implementation of these schemes and their feasibility.
