The degradation of Lithium-ion batteries(LIBs)during cycling is particularly exacerbated at low temperatures,which has a significant impact on the longevity of electric vehicles,energy storage systems,and consumer ele...The degradation of Lithium-ion batteries(LIBs)during cycling is particularly exacerbated at low temperatures,which has a significant impact on the longevity of electric vehicles,energy storage systems,and consumer electronics.A comprehensive understanding of the low-temperature aging mechanisms throughout the whole life cycle of LIBs is crucial.However,existing research is limited,which typically focuses on capacity degradation to 80%.To fill this gap,this paper conducts low-temperature cyclic aging tests at three different charging rates.The investigation employs differential voltage analysis,the distribution of relaxation times technique,and disassembly characterization to explore both thermodynamic degradation and kinetic degradation,alongside a correlation analysis of the factors influencing these degradation processes.The results reveal two distinct knee points in the capacity decline of LIBs during the whole life cycle,in contrast to prior studies identifying only one.Before the first knee point,the thickening of the SEI film dominates capacity loss,with higher charging rates accelerating the process.After the first knee point,the main degradation mechanisms shift to lithium plating and the fracture of the positive electrode active particles.These two aging factors become more pronounced with ongoing cycling,culminating in a second knee point in capacity decline.Notably,a novel finding demonstrates that after the second knee point,capacity degradation progresses faster at lower charging rates compared to medium rates.The reason is the fracture of graphite particles also becomes a critical contributor to the severe capacity degradation at lower charging rates.These insights will guide the designs of next-generation low-temperature LIBs and low-temperature battery management systems.展开更多
Guaranteeing the safety performance of chemical process units is the premise for the safety production of chemical enterprises.Only to have the system safety management of the whole life cycle of the process units can...Guaranteeing the safety performance of chemical process units is the premise for the safety production of chemical enterprises.Only to have the system safety management of the whole life cycle of the process units can operate the process systems under the state of controllable risk.展开更多
Lithium-ion batteries are the preferred green energy storage method and are equipped with intelligent battery management systems(BMSs)that efficiently manage the batteries.This not only ensures the safety performance ...Lithium-ion batteries are the preferred green energy storage method and are equipped with intelligent battery management systems(BMSs)that efficiently manage the batteries.This not only ensures the safety performance of the batteries but also significantly improves their efficiency and reduces their damage rate.Throughout their whole life cycle,lithium-ion batteries undergo aging and performance degradation due to diverse external environments and irregular degradation of internal materials.This degradation is reflected in the state of health(SOH)assessment.Therefore,this review offers the first comprehensive analysis of battery SOH estimation strategies across the entire lifecycle over the past five years,highlighting common research focuses rooted in data-driven methods.It delves into various dimensions such as dataset integration and preprocessing,health feature parameter extraction,and the construction of SOH estimation models.These approaches unearth hidden insights within data,addressing the inherent tension between computational complexity and estimation accuracy.To enha nce support for in-vehicle implementation,cloud computing,and the echelon technologies of battery recycling,remanufacturing,and reuse,as well as to offer insights into these technologies,a segmented management approach will be introduced in the future.This will encompass source domain data processing,multi-feature factor reconfiguration,hybrid drive modeling,parameter correction mechanisms,and fulltime health management.Based on the best SOH estimation outcomes,health strategies tailored to different stages can be devised in the future,leading to the establishment of a comprehensive SOH assessment framework.This will mitigate cross-domain distribution disparities and facilitate adaptation to a broader array of dynamic operation protocols.This article reviews the current research landscape from four perspectives and discusses the challenges that lie ahead.Researchers and practitioners can gain a comprehensive understanding of battery SOH estimation methods,offering valuable insights for the development of advanced battery management systems and embedded application research.展开更多
For facing the challenges brought by large-scale renewable energy having access to the system and considering the key technologies of energy Internet,it is very necessary to put forward the location method of distribu...For facing the challenges brought by large-scale renewable energy having access to the system and considering the key technologies of energy Internet,it is very necessary to put forward the location method of distribution network equipment and capacity from the perspective of life cycle cost.Compared with the traditional energy network,the equipment capacity problem of energy interconnected distribution network which involves in electricity network,thermal energy network and natural gas network is comprehensively considered in this paper.On this basis,firstly,the operation architecture of energy interconnected distribution network is designed.Secondly,taking the grid connection location and configuration capacity of key equipment in the system as the control variables and the operation cost of system comprehensive planning in the whole life cycle as the goal,the equipment location and capacity optimization model of energy interconnected distribution network is established.Finally,an IEEE 33 bus energy mutual distribution grid system is taken for example analysis,and the improved chaotic particle swarmoptimization algorithm is used to solve it.The simulation results show that the method proposed in this paper is suitable for the equipment location and capacity planning of energy interconnected distribution network,and it can effectively improve the social and economic benefits of system operation.展开更多
he cement sheath is the heart of any oil or gas well for providing zonal isolation and well integrity during the life of a well.Loads induced by well construction operations and borehole pressure and temperature chang...he cement sheath is the heart of any oil or gas well for providing zonal isolation and well integrity during the life of a well.Loads induced by well construction operations and borehole pressure and temperature changes may lead to the ultimate failure of cement sheath.This paper quantifies the potential of cement failure under mechanically and thermally induced stress during the life-of-well using a coupled thermalehydrologicalemechanical(THM)modeling approach.A staged finite-element procedure is presented considering sequential stress and displacement development during each stage of the well life,including drilling,casing,cementing,completion,production,and injection.The staged model quantifies the stress states and state variables,e.g.,plastic strain,damage,and debonding at cement/rock or cement/casing interface,in each well stage from simultaneous action of in-situ stress,pore pressure,temperature,casing pressure,and cement hardening/shrinkage.Thus,it eliminates the need to guess the initial stress and strain state before modeling a specific stage.Moreover,coupled THM capabilities of the model ensure the full consideration of the interaction between these influential factors.展开更多
Software credibility refers to the matching degree between the expected result and system behavior in the real running environment.This paper focuses on the application of software creditability verification method ba...Software credibility refers to the matching degree between the expected result and system behavior in the real running environment.This paper focuses on the application of software creditability verification method based on the application behavior declaration(ABD),in which the application of software credibility validation process and the software behavior declaration definition statement are put forward.In the integration of the process and the software development life cycle,the ABD is embedded into the software development phases to make the software behavior be consistent with the judgment and the final realization meet the requirement of trusted software verification.展开更多
A giant gasfield refers to a gasfield with proved geological reserves of natural gas more than 30 billion cubic meters,peak annual output of natural gas more than 1 billion cubic meters,and a certain plateau period.It...A giant gasfield refers to a gasfield with proved geological reserves of natural gas more than 30 billion cubic meters,peak annual output of natural gas more than 1 billion cubic meters,and a certain plateau period.It is an important foundation for the rapid growth of China's natural gas reserves and production and its long-term stable development in the future.And it is also the key to ensure the security of gas supply.By systematically analyzing the development practice of more than 260 gasfields at home and abroad and dissecting and simulating typical gasfields,this paper comprehensively studied the connotation,core technology and whole life cycle index system on the scientific development of giant gasfields.It is indicated that the scientific development connotation of giant gasfields consists of the following parts.First,the natural gas development concept with“water identification,control and treatment”as the technical system is put forward.That is to carry out“water-control development”in conventional gasfields and hydraulic fracturing development in unconventional gasfields.A reasonable gas production rate should be set according to the types and characteristics of gas reservoirs.Second,economic and social benefits of gasfield development should be evaluated comprehensively to ensure its long-term stable production.Third,the suitable production stabilization mode shall be adopted according to the production characteristics of gas wells and the development characteristics of reservoirs.Fourth,the recoverable reserves of a gasfield,the development laws of formation water and artificial waterflooding,the ultimate recovery technological countermeasures of the gasfield,the cost-effective stable period of the gasfield should be determined based on thefine description of conventional and unconventional gas reservoirs in different stages,the development characteristics of gas reservoirs and the monitoring results of production performance.The core technologies in the scientific development of giant gasfields include large-scale optimization technology,scientific well arrangement technology,balanced production technology and deep potential tapping technology.Based on this,several parameters are selected comprehensively as the key indexes for the scientific development of giant gasfields,such as production rate,pressure drop,degree of reserves recovery and output per unit pressure drop,and the whole life cycle index systems for four types of gas reservoirs are established,i.e.,high-pressure gas reservoirs,low-permeability and tight gas reservoirs,fracturedeporous reservoirs,and shale gas reservoirs.In conclusion,the research results enrich and improve the theories of natural gas development geology and are conducive to guiding the scientific development of different-type giant gasfields,thus further promoting the rapid development of natural gas industry in China.展开更多
This paper analyzes the large data thoughts in the support role of promote the innovation in asset management in colleges and universities, this paper discusses the use of big data raise the level of information manag...This paper analyzes the large data thoughts in the support role of promote the innovation in asset management in colleges and universities, this paper discusses the use of big data raise the level of information management, the practice of building the including purchasing management, asset management and high value assets, open sharing of total life cycle management information provides a data sharing platform of large data application, improve the service efficiency, and help to reform and develop the information management of instruments and equipment in colleges and universities through safety measures.展开更多
High-energy-density lithium metal batteries(LMBs)are widely accepted as promising next-generation energy storage systems.However,the safety features of practical LMBs are rarely explored quantitatively.Herein,the ther...High-energy-density lithium metal batteries(LMBs)are widely accepted as promising next-generation energy storage systems.However,the safety features of practical LMBs are rarely explored quantitatively.Herein,the thermal runaway behaviors of a 3.26 Ah(343 Wh kg^(−1))Li|LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)pouch cell in the whole life cycle are quantitatively investigated by extended volume-accelerating rate calorimetry and differential scanning calorimetry.By thermal failure analyses on pristine cell with fresh Li metal,activated cell with once plated dendrites,and 20-cycled cell with large quantities of dendrites and dead Li,dendrite-accelerated thermal runaway mechanisms including reaction sequence and heat release contribution are reached.Suppressing dendrite growth and reducing the reactivity between Li metal anode and electrolyte at high temperature are effective strategies to enhance the safety performance of LMBs.These findings can largely enhance the understanding on the thermal runaway behaviors of Li metal pouch cells in practical working conditions.展开更多
With the rapid development of China's economy,external dependence on petroleum resources continues to increase,and their security has become an important part of national security.To evaluate the security of China...With the rapid development of China's economy,external dependence on petroleum resources continues to increase,and their security has become an important part of national security.To evaluate the security of China's petroleum resource supply in a scientific and objective manner,this study establishes a corresponding petroleum life-cycle evaluation index system,based on the theory and method of the whole life-cycle security evaluation of mineral resources,and conducts further independence and grey correlation analysis on the indexes for the purpose of evaluating the petroleum risk situation in China,based on relevant public data from the past 10 years.The results show that the overall trend of China's oil risk has a“U”-shaped characteristic of first decreasing and then increasing.Furthermore,the analysis finds that China's mineral resources have been greatly influenced by the domestic production situation and international trade.These results suggest that the security of petroleum supply can be improved by safeguarding international trade in petroleum resources,strengthening the strategic reserves of domestic petroleum resources,and developing new alternative clean energy sources to improve the resilience of petroleum supply security.This study's research methodology is more logical and systematic than traditional methods,and the analysis of the factors is comprehensive and of high application value,providing implications for the establishment of a big data analysis and evaluation index system for oil resource security.展开更多
基金financially supported by the National Natural Science Foundation of China(NSFC,Grant number U20A20310)the Program of Shanghai Academic/Technology Research Leader(Grant number 22XD1423800)。
文摘The degradation of Lithium-ion batteries(LIBs)during cycling is particularly exacerbated at low temperatures,which has a significant impact on the longevity of electric vehicles,energy storage systems,and consumer electronics.A comprehensive understanding of the low-temperature aging mechanisms throughout the whole life cycle of LIBs is crucial.However,existing research is limited,which typically focuses on capacity degradation to 80%.To fill this gap,this paper conducts low-temperature cyclic aging tests at three different charging rates.The investigation employs differential voltage analysis,the distribution of relaxation times technique,and disassembly characterization to explore both thermodynamic degradation and kinetic degradation,alongside a correlation analysis of the factors influencing these degradation processes.The results reveal two distinct knee points in the capacity decline of LIBs during the whole life cycle,in contrast to prior studies identifying only one.Before the first knee point,the thickening of the SEI film dominates capacity loss,with higher charging rates accelerating the process.After the first knee point,the main degradation mechanisms shift to lithium plating and the fracture of the positive electrode active particles.These two aging factors become more pronounced with ongoing cycling,culminating in a second knee point in capacity decline.Notably,a novel finding demonstrates that after the second knee point,capacity degradation progresses faster at lower charging rates compared to medium rates.The reason is the fracture of graphite particles also becomes a critical contributor to the severe capacity degradation at lower charging rates.These insights will guide the designs of next-generation low-temperature LIBs and low-temperature battery management systems.
文摘Guaranteeing the safety performance of chemical process units is the premise for the safety production of chemical enterprises.Only to have the system safety management of the whole life cycle of the process units can operate the process systems under the state of controllable risk.
基金supported by the National Natural Science Foundation of China (No.62173281,52377217,U23A20651)Sichuan Science and Technology Program (No.24NSFSC0024,23ZDYF0734,23NSFSC1436)+2 种基金Dazhou City School Cooperation Project (No.DZXQHZ006)Technopole Talent Summit Project (No.KJCRCFH08)Robert Gordon University。
文摘Lithium-ion batteries are the preferred green energy storage method and are equipped with intelligent battery management systems(BMSs)that efficiently manage the batteries.This not only ensures the safety performance of the batteries but also significantly improves their efficiency and reduces their damage rate.Throughout their whole life cycle,lithium-ion batteries undergo aging and performance degradation due to diverse external environments and irregular degradation of internal materials.This degradation is reflected in the state of health(SOH)assessment.Therefore,this review offers the first comprehensive analysis of battery SOH estimation strategies across the entire lifecycle over the past five years,highlighting common research focuses rooted in data-driven methods.It delves into various dimensions such as dataset integration and preprocessing,health feature parameter extraction,and the construction of SOH estimation models.These approaches unearth hidden insights within data,addressing the inherent tension between computational complexity and estimation accuracy.To enha nce support for in-vehicle implementation,cloud computing,and the echelon technologies of battery recycling,remanufacturing,and reuse,as well as to offer insights into these technologies,a segmented management approach will be introduced in the future.This will encompass source domain data processing,multi-feature factor reconfiguration,hybrid drive modeling,parameter correction mechanisms,and fulltime health management.Based on the best SOH estimation outcomes,health strategies tailored to different stages can be devised in the future,leading to the establishment of a comprehensive SOH assessment framework.This will mitigate cross-domain distribution disparities and facilitate adaptation to a broader array of dynamic operation protocols.This article reviews the current research landscape from four perspectives and discusses the challenges that lie ahead.Researchers and practitioners can gain a comprehensive understanding of battery SOH estimation methods,offering valuable insights for the development of advanced battery management systems and embedded application research.
基金The authors received specific funding for State Grid Corporation Headquarters Project Support,Key Technologies and Applications of Planning and Decision-Making Based on the Full Cost Chain of the Power Grid,Grant No.5205331800001.
文摘For facing the challenges brought by large-scale renewable energy having access to the system and considering the key technologies of energy Internet,it is very necessary to put forward the location method of distribution network equipment and capacity from the perspective of life cycle cost.Compared with the traditional energy network,the equipment capacity problem of energy interconnected distribution network which involves in electricity network,thermal energy network and natural gas network is comprehensively considered in this paper.On this basis,firstly,the operation architecture of energy interconnected distribution network is designed.Secondly,taking the grid connection location and configuration capacity of key equipment in the system as the control variables and the operation cost of system comprehensive planning in the whole life cycle as the goal,the equipment location and capacity optimization model of energy interconnected distribution network is established.Finally,an IEEE 33 bus energy mutual distribution grid system is taken for example analysis,and the improved chaotic particle swarmoptimization algorithm is used to solve it.The simulation results show that the method proposed in this paper is suitable for the equipment location and capacity planning of energy interconnected distribution network,and it can effectively improve the social and economic benefits of system operation.
基金This work was financially supported by Science Foundation of China University of Petroleum,Beijing(No.2462019BJRC011 and No.2462020YXZZ051)National Natural Science Foundation of China(No.52004298).
文摘he cement sheath is the heart of any oil or gas well for providing zonal isolation and well integrity during the life of a well.Loads induced by well construction operations and borehole pressure and temperature changes may lead to the ultimate failure of cement sheath.This paper quantifies the potential of cement failure under mechanically and thermally induced stress during the life-of-well using a coupled thermalehydrologicalemechanical(THM)modeling approach.A staged finite-element procedure is presented considering sequential stress and displacement development during each stage of the well life,including drilling,casing,cementing,completion,production,and injection.The staged model quantifies the stress states and state variables,e.g.,plastic strain,damage,and debonding at cement/rock or cement/casing interface,in each well stage from simultaneous action of in-situ stress,pore pressure,temperature,casing pressure,and cement hardening/shrinkage.Thus,it eliminates the need to guess the initial stress and strain state before modeling a specific stage.Moreover,coupled THM capabilities of the model ensure the full consideration of the interaction between these influential factors.
基金Supported by Foundation of the National Public Scientific Research(201210262)
文摘Software credibility refers to the matching degree between the expected result and system behavior in the real running environment.This paper focuses on the application of software creditability verification method based on the application behavior declaration(ABD),in which the application of software credibility validation process and the software behavior declaration definition statement are put forward.In the integration of the process and the software development life cycle,the ABD is embedded into the software development phases to make the software behavior be consistent with the judgment and the final realization meet the requirement of trusted software verification.
基金supported by the National Science and Technology Major Project"Giant Oil and Gas Fields and CBM Development"(No.:2016ZX05015).
文摘A giant gasfield refers to a gasfield with proved geological reserves of natural gas more than 30 billion cubic meters,peak annual output of natural gas more than 1 billion cubic meters,and a certain plateau period.It is an important foundation for the rapid growth of China's natural gas reserves and production and its long-term stable development in the future.And it is also the key to ensure the security of gas supply.By systematically analyzing the development practice of more than 260 gasfields at home and abroad and dissecting and simulating typical gasfields,this paper comprehensively studied the connotation,core technology and whole life cycle index system on the scientific development of giant gasfields.It is indicated that the scientific development connotation of giant gasfields consists of the following parts.First,the natural gas development concept with“water identification,control and treatment”as the technical system is put forward.That is to carry out“water-control development”in conventional gasfields and hydraulic fracturing development in unconventional gasfields.A reasonable gas production rate should be set according to the types and characteristics of gas reservoirs.Second,economic and social benefits of gasfield development should be evaluated comprehensively to ensure its long-term stable production.Third,the suitable production stabilization mode shall be adopted according to the production characteristics of gas wells and the development characteristics of reservoirs.Fourth,the recoverable reserves of a gasfield,the development laws of formation water and artificial waterflooding,the ultimate recovery technological countermeasures of the gasfield,the cost-effective stable period of the gasfield should be determined based on thefine description of conventional and unconventional gas reservoirs in different stages,the development characteristics of gas reservoirs and the monitoring results of production performance.The core technologies in the scientific development of giant gasfields include large-scale optimization technology,scientific well arrangement technology,balanced production technology and deep potential tapping technology.Based on this,several parameters are selected comprehensively as the key indexes for the scientific development of giant gasfields,such as production rate,pressure drop,degree of reserves recovery and output per unit pressure drop,and the whole life cycle index systems for four types of gas reservoirs are established,i.e.,high-pressure gas reservoirs,low-permeability and tight gas reservoirs,fracturedeporous reservoirs,and shale gas reservoirs.In conclusion,the research results enrich and improve the theories of natural gas development geology and are conducive to guiding the scientific development of different-type giant gasfields,thus further promoting the rapid development of natural gas industry in China.
文摘This paper analyzes the large data thoughts in the support role of promote the innovation in asset management in colleges and universities, this paper discusses the use of big data raise the level of information management, the practice of building the including purchasing management, asset management and high value assets, open sharing of total life cycle management information provides a data sharing platform of large data application, improve the service efficiency, and help to reform and develop the information management of instruments and equipment in colleges and universities through safety measures.
基金Beijing Municipal Natural Science Foundation(Z200011)National Key Research and Development Program(2021YFB2500300)National Natural Science Foundation of China(22179070,22075029,U1932220),the“Shuimu Tsinghua Scholar Program of Tsinghua University”,and Mercedes-Benz AG.Xiang-Qun Xu and Xin-Bing Cheng contributed equally to this work.
文摘High-energy-density lithium metal batteries(LMBs)are widely accepted as promising next-generation energy storage systems.However,the safety features of practical LMBs are rarely explored quantitatively.Herein,the thermal runaway behaviors of a 3.26 Ah(343 Wh kg^(−1))Li|LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)pouch cell in the whole life cycle are quantitatively investigated by extended volume-accelerating rate calorimetry and differential scanning calorimetry.By thermal failure analyses on pristine cell with fresh Li metal,activated cell with once plated dendrites,and 20-cycled cell with large quantities of dendrites and dead Li,dendrite-accelerated thermal runaway mechanisms including reaction sequence and heat release contribution are reached.Suppressing dendrite growth and reducing the reactivity between Li metal anode and electrolyte at high temperature are effective strategies to enhance the safety performance of LMBs.These findings can largely enhance the understanding on the thermal runaway behaviors of Li metal pouch cells in practical working conditions.
基金This work was financially supported by the Fundamental Research Funds for Central Universities(Grant No.2021NTSS10)the National Natural Science Foundation of China(Grant No.72004141).
文摘With the rapid development of China's economy,external dependence on petroleum resources continues to increase,and their security has become an important part of national security.To evaluate the security of China's petroleum resource supply in a scientific and objective manner,this study establishes a corresponding petroleum life-cycle evaluation index system,based on the theory and method of the whole life-cycle security evaluation of mineral resources,and conducts further independence and grey correlation analysis on the indexes for the purpose of evaluating the petroleum risk situation in China,based on relevant public data from the past 10 years.The results show that the overall trend of China's oil risk has a“U”-shaped characteristic of first decreasing and then increasing.Furthermore,the analysis finds that China's mineral resources have been greatly influenced by the domestic production situation and international trade.These results suggest that the security of petroleum supply can be improved by safeguarding international trade in petroleum resources,strengthening the strategic reserves of domestic petroleum resources,and developing new alternative clean energy sources to improve the resilience of petroleum supply security.This study's research methodology is more logical and systematic than traditional methods,and the analysis of the factors is comprehensive and of high application value,providing implications for the establishment of a big data analysis and evaluation index system for oil resource security.
