Developing deep fragmented soft coalbed methane(CBM)can significantly enhance domestic natural gas supplies,reduce reliance on imported energy,and bolster national energy security.This manuscript provides a comprehens...Developing deep fragmented soft coalbed methane(CBM)can significantly enhance domestic natural gas supplies,reduce reliance on imported energy,and bolster national energy security.This manuscript provides a comprehensive review of commonly employed coalbed methane extraction technologies.It then delves into several critical issues in the current stage of CBM exploration and development in China,including the compatibility of existing technologies with CBM reservoirs,the characteristics and occurrence states of CBM reservoirs,critical desorption pressure,and gas generation mechanisms.Our research indicates that current CBM exploration and development technologies in China have reached an internationally advanced level,yet the industry is facing unprecedented challenges.Despite progress in low-permeability,high-value coal seams,significant breakthroughs have not been achieved in exploring other types of coal seams.For different coal reservoirs,integrated extraction technologies have been developed,such as surface pre-depressurisation and segmented hydraulic fracturing of coal seam roof strata.Additionally,techniques like large-scale volume fracturing in horizontal wells have been established,significantly enhancing reservoir stimulation effects and coalbed methane recovery rates.However,all of these technologies are fundamentally based on permeation.These technologies lack direct methods aimed at enhancing the diffusion rate of CBM,thereby failing to fully reflect the unique characteristics of CBM.Current CBM exploration and development theories and technologies are not universally applicable to all coal seams.They do not adequately account for the predominantly adsorbed state of CBM,and the complex and variable gas generation mechanisms further constrain CBM development in China.Finally,continuous exploration of new deep CBM exploration technologies is necessary.Integrating more effective reservoir stimulation technologies is essential to enhance technical adaptability concerning CBM reservoir characteristics,gas occurrence states,and gas generation mechanisms,ultimately achieving efficient CBM development.We conclude that while China possesses a substantial foundation of deep fractured CBM resources,industry development is constrained and requires continuous exploration of new CBM exploration and development technologies to utilize these resources effectively.展开更多
Utilizing energy storage in depleted oil and gas reservoirs can improve productivity while reducing power costs and is one of the best ways to achieve synergistic development of"Carbon Peak–Carbon Neutral"a...Utilizing energy storage in depleted oil and gas reservoirs can improve productivity while reducing power costs and is one of the best ways to achieve synergistic development of"Carbon Peak–Carbon Neutral"and"Underground Resource Utiliza-tion".Starting from the development of Compressed Air Energy Storage(CAES)technology,the site selection of CAES in depleted gas and oil reservoirs,the evolution mechanism of reservoir dynamic sealing,and the high-flow CAES and injection technology are summarized.It focuses on analyzing the characteristics,key equipment,reservoir construction,application scenarios and cost analysis of CAES projects,and sorting out the technical key points and existing difficulties.The devel-opment trend of CAES technology is proposed,and the future development path is scrutinized to provide reference for the research of CAES projects in depleted oil and gas reservoirs.展开更多
This paper presents an overview of the recent developments in hybrid wind-wave energy.With the focus on floating concepts,the possible configurations introduced in the literature are categorized and depicted,and the m...This paper presents an overview of the recent developments in hybrid wind-wave energy.With the focus on floating concepts,the possible configurations introduced in the literature are categorized and depicted,and the main conclusions obtained from the references are summarized.Moreover,offshore wind and wave resources are discussed in terms of complementarity and supplementarity,offering a new perspective to developing hybrid wind-wave energy systems that look for synergies not limited to maximizing power output.Then,the feasibility of the concepts under development is discussed in detail,with focus on technical feasibility,dynamic feasibility and limitations of the methods employed.The hybrid configurations that surpassed the experimental validation phase are highlighted,and the experimental results are summarized.By compiling more than 40 floating wind turbine concepts,new relations are drawn between power,wind turbine dimensions,platforms’draft and displacement,which are further related to the payload allowance of the units to accommodate wave devices and onboard power take-off systems.Bearing in mind that it is a challenge to model the exact dynamics of hybrid floating wind-wave platforms,this paper elucidates the current research gaps,limitations and future trends in the field.Lastly,based on the overview and topics discussed,several major conclusions are drawn concerning hybrid synergies,dynamics and hydrodynamics of hybrid platforms,feasibility of concepts,among other regards.展开更多
Super-heavy oil is a significant unconventional energy source,and more than 30 years of research have shown that steam-assisted gravity drainage(SAGD)technology is suitable for thick super-heavy oil reservoirs.Recentl...Super-heavy oil is a significant unconventional energy source,and more than 30 years of research have shown that steam-assisted gravity drainage(SAGD)technology is suitable for thick super-heavy oil reservoirs.Recently,more and more thin-layer super-heavy oil reservoirs have been discovered in China,while their deep buried depth and serous heterogeneity make the existing SAGD technology difficult to apply,so it is urgent to improve the existing SAGD technology for the thin-layer super-heavy oil.To this end,this paper focuses on the enlightenment of field application in SAGD technology.Firstly,based on typical SAGD field projects,the development history of SAGD technology in the world was reviewed,and the influence of reservoir physical properties on the application of SAGD technology in thin-layer superheavy oil reservoirs was analyzed.Secondly,the well pattern,wellbore structure,pre-heating,artificial lift,and monitor technique of SAGD were detailed described,and their adjustment direction was expounded for the development of thin-layer super-heavy oil reservoirs.Lastly,the gas-and solventassistant SAGD were comprehensively evaluated,and their application potential in thin-layer superheavy oil reservoirs was studied.The research results can provide theoretical guidance for the application of SAGD technology in thin-layer super-heavy oil reservoirs.展开更多
[Objective] This study aimed to provide references for the application of participatory monitoring and evaluation in the development of animal husbandry tech- nology. [Method] With the livelihood improvement program f...[Objective] This study aimed to provide references for the application of participatory monitoring and evaluation in the development of animal husbandry tech- nology. [Method] With the livelihood improvement program for agricultural and pas- toral area in northern Yunnan as the example, the development process of partici- patory animal husbandry was overviewed. And the monitoring and evaluation pro- cesses of participatory animal husbandry were introduced and analyzed. [Result] The monitoring and evaluation indicator system of participatory animal husbandry technol- ogy included 4 layers, namely technology, institutional system, personnel ability con- struction and effectiveness, and 11 third-level indicators, namely, technical characteristics, superiority-inferiority comparison, community and farmers, technical personnel, project personnel, economic indicators and social indicators. [Conclusion] This study provided the references for the application of participatory monitoring and evaluation in the development of animal husbandry technology.展开更多
Recent progress in the physics and engineering design study for themodification programme of JT-60 is presented. In order to achieve a steady state high-βplasmaoperation, which is the dominant issue of this programme...Recent progress in the physics and engineering design study for themodification programme of JT-60 is presented. In order to achieve a steady state high-βplasmaoperation, which is the dominant issue of this programme, physics design for the MHD control and thestability analysis is investigated. Engineering design and the R & D for the superconducting coils,irradiation shield are performed well towards the mission of programme.展开更多
The topic was concentrated on environmental technology development in China within the context of China's economic acceleration and reform. Firstly, cleaner technology should be adopted where possible in indu...The topic was concentrated on environmental technology development in China within the context of China's economic acceleration and reform. Firstly, cleaner technology should be adopted where possible in industrial production; secondly, eco agricultural technological system, especially biological technology, should be developed in agricultural production; thirdly, end of pipe solution should focus on waste utilization or recycling technology where appropriate clean technology does not exist; lastly but not the least, existing technologies to minimize eco environmental deterioration such as soil erosion, salinization, desertification and deforestation should also be extended and developed. The mentioned ways of environmental technology development can only be realized on the condition that a resource conservation based production system and life style could be established and appropriate policy secured.展开更多
Using mathematical plasticity theories, universal formability (UF) technology has been developed and applied in the automotive stamping engineering and production. As a formability analysis tool, this technology is th...Using mathematical plasticity theories, universal formability (UF) technology has been developed and applied in the automotive stamping engineering and production. As a formability analysis tool, this technology is the major methodology for the development of stamping expert system (solution provider) for (a) product design and feasibility analysis, (b) material automatic selection using nomograms, (c) draw die design using pre-models, and (d) UF and robustness analysis of die performance in finite element analysis (FEA) environment.展开更多
It is the most available way to obtain self-rooted seedlings by tissue culture,which could breed de-virus seedlings with uniform traits and contribute to improve seedling quality.To construct a complete and efficient ...It is the most available way to obtain self-rooted seedlings by tissue culture,which could breed de-virus seedlings with uniform traits and contribute to improve seedling quality.To construct a complete and efficient technology system,this test used stem with buds of 16 cultivars and super lines including Yali,Jingbaili,03-04-034,03-08-080 and so on as materials to study the best way for explant sampling time and position,sterilization time using HgCl 2 and hormone concentrations.The result indicated that the optimum technology system was that the middle parts of longest shoots before 20 d after full-blossom were sterilized for 8 min by 0.1%HgCl 2 and inoculated on the development medium MS+6-BA 0.5 mg/L+IBA 0.2 mg/L+saccharose 3%+agar 0.6%(pH=5.8),and then trans-inoculated into propagation medium MS+6-BA 1.0 mg/L+IBA 0.3 mg/L+saccharose 3%+agar 0.6%(pH=5.8).展开更多
Environmental technology (ET) refers to the processes and techniques for environmental prevention, reduction, recycling, reuse and rehabilitation. Since 1978, China has launched a series of R&D programs in promoti...Environmental technology (ET) refers to the processes and techniques for environmental prevention, reduction, recycling, reuse and rehabilitation. Since 1978, China has launched a series of R&D programs in promoting environmental science and technology development. Uneven spatial distribution and sectoral structure give us a profile of the present status of ET in China. Both opportunities and constraints are analyzed for the development of ET, and strategies for its future development are presented in this paper.展开更多
Currently, the progress of science and technology has become a key factor in promoting economic development. And the backwardness of science and technology at the grassroots level has undoubtedly restricted the proces...Currently, the progress of science and technology has become a key factor in promoting economic development. And the backwardness of science and technology at the grassroots level has undoubtedly restricted the process of China’s construction of socialist new countryside. Taking socio-economy and the devel- opment of science and technology in Jiaxing as a breakthrough point, and based on the related data of Jiaxing during 1998?2004, this paper analyzes thoroughly the interactive relationship be- tween socio-economy and the development of science and tech- nology. This paper strives to summarize the development track and model of the grassroots work of science and technology so as to provide local governments with references and grounds for drawing up policies for the local work of science and technology.展开更多
China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rel...China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rely on the existing technology, it is crucial to accelerate the new technology development. This article discusses the perspective of various new technologies from the available energy resources and the required increase of electric power.展开更多
On the occasion of celebrating the 45th anniversary of the founding of the Chinese Academy of Sciences(CAS), in recalling the development history of the CAS’s international exchange and cooperation,we feel gratified ...On the occasion of celebrating the 45th anniversary of the founding of the Chinese Academy of Sciences(CAS), in recalling the development history of the CAS’s international exchange and cooperation,we feel gratified to see that it has entered into an unprecedented era of dynamic expansion and progress. The CAS’s international cooperation experienced a stage of "exchange only with eastern countries" in its inceptive years and at a time of actual stagnation in"cultural revolution". It was the Third Session of the Eleventh Congress of the Chinese Communist展开更多
A few years ago, the present author had the opportunity to study the iron clamps of the archaic and classical temples. This research led to very interesting results concerning the development of technology applied in ...A few years ago, the present author had the opportunity to study the iron clamps of the archaic and classical temples. This research led to very interesting results concerning the development of technology applied in making those clamps and what is more its rapid evolution in a very short period. For instance, the technology in making the clamps of Parthenon and those of the Epikourios Apollo differs completely, although the latter was erected by the same engineer, Iktinos. Actually, it is a revolutionary one as compared with that applied in the erection of Parthenon. The paper starts by examining the making of the archaic Trapeza iron clamps and continue with those of the Parthenon and the Epikourios Apollo.展开更多
The future wireless communication system requires higher data transmission rates and better QoS. Therefore, the system capacity should be greatly improved, which can be fulfilled only by great improvements in the spec...The future wireless communication system requires higher data transmission rates and better QoS. Therefore, the system capacity should be greatly improved, which can be fulfilled only by great improvements in the spectrum efficiency due to limited radio frequency resources. The Multiple Input Multiple Output (MIMO) technology is a good choice for future wireless communications. The most study of MIMO focuses on the MIMO channel, MIMO transceiver, distributed MIMO and application of MIMO. The MIMO technology is a great technological breakthrough in the field of wireless communications. It is expected to become a key technology for the future broadband mobile communication system and wireless broadband access system.展开更多
基金supported by the National Natural Science Foundation of China(52074045,52274074)the Science Fund for Distinguished Young Scholars of Chongqing(CSTB2022NSCQ-JQX0028).
文摘Developing deep fragmented soft coalbed methane(CBM)can significantly enhance domestic natural gas supplies,reduce reliance on imported energy,and bolster national energy security.This manuscript provides a comprehensive review of commonly employed coalbed methane extraction technologies.It then delves into several critical issues in the current stage of CBM exploration and development in China,including the compatibility of existing technologies with CBM reservoirs,the characteristics and occurrence states of CBM reservoirs,critical desorption pressure,and gas generation mechanisms.Our research indicates that current CBM exploration and development technologies in China have reached an internationally advanced level,yet the industry is facing unprecedented challenges.Despite progress in low-permeability,high-value coal seams,significant breakthroughs have not been achieved in exploring other types of coal seams.For different coal reservoirs,integrated extraction technologies have been developed,such as surface pre-depressurisation and segmented hydraulic fracturing of coal seam roof strata.Additionally,techniques like large-scale volume fracturing in horizontal wells have been established,significantly enhancing reservoir stimulation effects and coalbed methane recovery rates.However,all of these technologies are fundamentally based on permeation.These technologies lack direct methods aimed at enhancing the diffusion rate of CBM,thereby failing to fully reflect the unique characteristics of CBM.Current CBM exploration and development theories and technologies are not universally applicable to all coal seams.They do not adequately account for the predominantly adsorbed state of CBM,and the complex and variable gas generation mechanisms further constrain CBM development in China.Finally,continuous exploration of new deep CBM exploration technologies is necessary.Integrating more effective reservoir stimulation technologies is essential to enhance technical adaptability concerning CBM reservoir characteristics,gas occurrence states,and gas generation mechanisms,ultimately achieving efficient CBM development.We conclude that while China possesses a substantial foundation of deep fractured CBM resources,industry development is constrained and requires continuous exploration of new CBM exploration and development technologies to utilize these resources effectively.
基金the financial support from the Scientific Research and Technology Development Project of China Energy Engineering Corporation Limited(CEEC-KJZX-04).
文摘Utilizing energy storage in depleted oil and gas reservoirs can improve productivity while reducing power costs and is one of the best ways to achieve synergistic development of"Carbon Peak–Carbon Neutral"and"Underground Resource Utiliza-tion".Starting from the development of Compressed Air Energy Storage(CAES)technology,the site selection of CAES in depleted gas and oil reservoirs,the evolution mechanism of reservoir dynamic sealing,and the high-flow CAES and injection technology are summarized.It focuses on analyzing the characteristics,key equipment,reservoir construction,application scenarios and cost analysis of CAES projects,and sorting out the technical key points and existing difficulties.The devel-opment trend of CAES technology is proposed,and the future development path is scrutinized to provide reference for the research of CAES projects in depleted oil and gas reservoirs.
基金supported by the Portuguese Foundation for Science and Technology(Fundação para a Ciência e Tecnologia-FCT)it contributes to the Strategic Research Plan of the Centre for Marine Technology and Ocean Engineering(Grant No.UIDB/UIDP/00134/2020)funded the first author for his PhD Scholarship(Grant No.SFRH/BD/145602/2019).
文摘This paper presents an overview of the recent developments in hybrid wind-wave energy.With the focus on floating concepts,the possible configurations introduced in the literature are categorized and depicted,and the main conclusions obtained from the references are summarized.Moreover,offshore wind and wave resources are discussed in terms of complementarity and supplementarity,offering a new perspective to developing hybrid wind-wave energy systems that look for synergies not limited to maximizing power output.Then,the feasibility of the concepts under development is discussed in detail,with focus on technical feasibility,dynamic feasibility and limitations of the methods employed.The hybrid configurations that surpassed the experimental validation phase are highlighted,and the experimental results are summarized.By compiling more than 40 floating wind turbine concepts,new relations are drawn between power,wind turbine dimensions,platforms’draft and displacement,which are further related to the payload allowance of the units to accommodate wave devices and onboard power take-off systems.Bearing in mind that it is a challenge to model the exact dynamics of hybrid floating wind-wave platforms,this paper elucidates the current research gaps,limitations and future trends in the field.Lastly,based on the overview and topics discussed,several major conclusions are drawn concerning hybrid synergies,dynamics and hydrodynamics of hybrid platforms,feasibility of concepts,among other regards.
基金financially supported by the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant Nos.CUGGC09 and CUG200637)Opening Fund of Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)),Ministry of Education(Grant No.19CX05005A-201)the Sinopec Science and Technology Department(Grant Nos.P2006 and 33550000-21-ZC0611-0006)。
文摘Super-heavy oil is a significant unconventional energy source,and more than 30 years of research have shown that steam-assisted gravity drainage(SAGD)technology is suitable for thick super-heavy oil reservoirs.Recently,more and more thin-layer super-heavy oil reservoirs have been discovered in China,while their deep buried depth and serous heterogeneity make the existing SAGD technology difficult to apply,so it is urgent to improve the existing SAGD technology for the thin-layer super-heavy oil.To this end,this paper focuses on the enlightenment of field application in SAGD technology.Firstly,based on typical SAGD field projects,the development history of SAGD technology in the world was reviewed,and the influence of reservoir physical properties on the application of SAGD technology in thin-layer superheavy oil reservoirs was analyzed.Secondly,the well pattern,wellbore structure,pre-heating,artificial lift,and monitor technique of SAGD were detailed described,and their adjustment direction was expounded for the development of thin-layer super-heavy oil reservoirs.Lastly,the gas-and solventassistant SAGD were comprehensively evaluated,and their application potential in thin-layer superheavy oil reservoirs was studied.The research results can provide theoretical guidance for the application of SAGD technology in thin-layer super-heavy oil reservoirs.
基金Supported by the Canadian International Development Research Center(IDRC)~~
文摘[Objective] This study aimed to provide references for the application of participatory monitoring and evaluation in the development of animal husbandry tech- nology. [Method] With the livelihood improvement program for agricultural and pas- toral area in northern Yunnan as the example, the development process of partici- patory animal husbandry was overviewed. And the monitoring and evaluation pro- cesses of participatory animal husbandry were introduced and analyzed. [Result] The monitoring and evaluation indicator system of participatory animal husbandry technol- ogy included 4 layers, namely technology, institutional system, personnel ability con- struction and effectiveness, and 11 third-level indicators, namely, technical characteristics, superiority-inferiority comparison, community and farmers, technical personnel, project personnel, economic indicators and social indicators. [Conclusion] This study provided the references for the application of participatory monitoring and evaluation in the development of animal husbandry technology.
文摘Recent progress in the physics and engineering design study for themodification programme of JT-60 is presented. In order to achieve a steady state high-βplasmaoperation, which is the dominant issue of this programme, physics design for the MHD control and thestability analysis is investigated. Engineering design and the R & D for the superconducting coils,irradiation shield are performed well towards the mission of programme.
文摘The topic was concentrated on environmental technology development in China within the context of China's economic acceleration and reform. Firstly, cleaner technology should be adopted where possible in industrial production; secondly, eco agricultural technological system, especially biological technology, should be developed in agricultural production; thirdly, end of pipe solution should focus on waste utilization or recycling technology where appropriate clean technology does not exist; lastly but not the least, existing technologies to minimize eco environmental deterioration such as soil erosion, salinization, desertification and deforestation should also be extended and developed. The mentioned ways of environmental technology development can only be realized on the condition that a resource conservation based production system and life style could be established and appropriate policy secured.
文摘Using mathematical plasticity theories, universal formability (UF) technology has been developed and applied in the automotive stamping engineering and production. As a formability analysis tool, this technology is the major methodology for the development of stamping expert system (solution provider) for (a) product design and feasibility analysis, (b) material automatic selection using nomograms, (c) draw die design using pre-models, and (d) UF and robustness analysis of die performance in finite element analysis (FEA) environment.
基金Supported by Projects from Hebei Natural Science Fund Committee(C2018301032)Hebei Support Project(16226312D-3)Innovation Team Project of Hebei Academy of Agriculture and Forest(C19R0601-2).
文摘It is the most available way to obtain self-rooted seedlings by tissue culture,which could breed de-virus seedlings with uniform traits and contribute to improve seedling quality.To construct a complete and efficient technology system,this test used stem with buds of 16 cultivars and super lines including Yali,Jingbaili,03-04-034,03-08-080 and so on as materials to study the best way for explant sampling time and position,sterilization time using HgCl 2 and hormone concentrations.The result indicated that the optimum technology system was that the middle parts of longest shoots before 20 d after full-blossom were sterilized for 8 min by 0.1%HgCl 2 and inoculated on the development medium MS+6-BA 0.5 mg/L+IBA 0.2 mg/L+saccharose 3%+agar 0.6%(pH=5.8),and then trans-inoculated into propagation medium MS+6-BA 1.0 mg/L+IBA 0.3 mg/L+saccharose 3%+agar 0.6%(pH=5.8).
文摘Environmental technology (ET) refers to the processes and techniques for environmental prevention, reduction, recycling, reuse and rehabilitation. Since 1978, China has launched a series of R&D programs in promoting environmental science and technology development. Uneven spatial distribution and sectoral structure give us a profile of the present status of ET in China. Both opportunities and constraints are analyzed for the development of ET, and strategies for its future development are presented in this paper.
文摘Currently, the progress of science and technology has become a key factor in promoting economic development. And the backwardness of science and technology at the grassroots level has undoubtedly restricted the process of China’s construction of socialist new countryside. Taking socio-economy and the devel- opment of science and technology in Jiaxing as a breakthrough point, and based on the related data of Jiaxing during 1998?2004, this paper analyzes thoroughly the interactive relationship be- tween socio-economy and the development of science and tech- nology. This paper strives to summarize the development track and model of the grassroots work of science and technology so as to provide local governments with references and grounds for drawing up policies for the local work of science and technology.
文摘China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rely on the existing technology, it is crucial to accelerate the new technology development. This article discusses the perspective of various new technologies from the available energy resources and the required increase of electric power.
文摘On the occasion of celebrating the 45th anniversary of the founding of the Chinese Academy of Sciences(CAS), in recalling the development history of the CAS’s international exchange and cooperation,we feel gratified to see that it has entered into an unprecedented era of dynamic expansion and progress. The CAS’s international cooperation experienced a stage of "exchange only with eastern countries" in its inceptive years and at a time of actual stagnation in"cultural revolution". It was the Third Session of the Eleventh Congress of the Chinese Communist
文摘A few years ago, the present author had the opportunity to study the iron clamps of the archaic and classical temples. This research led to very interesting results concerning the development of technology applied in making those clamps and what is more its rapid evolution in a very short period. For instance, the technology in making the clamps of Parthenon and those of the Epikourios Apollo differs completely, although the latter was erected by the same engineer, Iktinos. Actually, it is a revolutionary one as compared with that applied in the erection of Parthenon. The paper starts by examining the making of the archaic Trapeza iron clamps and continue with those of the Parthenon and the Epikourios Apollo.
基金Program ofNational Natural Science Foundation of China(No. 60496313) Project of National ResearchFoundation for the Doctoral Program of Ministryof Education of China (No. 20020614001)
文摘The future wireless communication system requires higher data transmission rates and better QoS. Therefore, the system capacity should be greatly improved, which can be fulfilled only by great improvements in the spectrum efficiency due to limited radio frequency resources. The Multiple Input Multiple Output (MIMO) technology is a good choice for future wireless communications. The most study of MIMO focuses on the MIMO channel, MIMO transceiver, distributed MIMO and application of MIMO. The MIMO technology is a great technological breakthrough in the field of wireless communications. It is expected to become a key technology for the future broadband mobile communication system and wireless broadband access system.
