The rapid growth of distributed renewable energy penetration is promoting the evolution of the energy system toward decentralization and decentralized and digitized smart grids.This study was based on energy blockchai...The rapid growth of distributed renewable energy penetration is promoting the evolution of the energy system toward decentralization and decentralized and digitized smart grids.This study was based on energy blockchain,and developed a dual-biding mechanism based on the real-time energy surplus and demand in the local smart grid,which is expected to enable reliable,affordable,and clean energy supply in smart communities.In the proposed system,economic benefits could be achieved by replacing fossil-fuel-based electricity with the high penetration of affordable solar PV electricity.The reduction of energy surplus realized by distributed energy production and P2P energy trading,within the smart grid results in less transmission loss and lower requirements for costly upgrading of existing grids.By adopting energy blockchain and smart contract technologies,energy secure trading with a low risk of privacy leakage could be accommodated.The prototype is examined through a case study,and the feasibility and efficiency of the proposed mechanism are further validated by scenario analysis.展开更多
Energy supply is one of the most critical challenges of wireless sensor networks(WSNs)and industrial wireless sensor networks(IWSNs).While research on coverage optimization problem(COP)centers on the network’s monito...Energy supply is one of the most critical challenges of wireless sensor networks(WSNs)and industrial wireless sensor networks(IWSNs).While research on coverage optimization problem(COP)centers on the network’s monitoring coverage,this research focuses on the power banks’energy supply coverage.The study of 2-D and 3-D spaces is typical in IWSN,with the realistic environment being more complex with obstacles(i.e.,machines).A 3-D surface is the field of interest(FOI)in this work with the established hybrid power bank deployment model for the energy supply COP optimization of IWSN.The hybrid power bank deployment model is highly adaptive and flexible for new or existing plants already using the IWSN system.The model improves the power supply to a more considerable extent with the least number of power bank deployments.The main innovation in this work is the utilization of a more practical surface model with obstacles and training while improving the convergence speed and quality of the heuristic algorithm.An overall probabilistic coverage rate analysis of every point on the FOI is provided,not limiting the scope to target points or areas.Bresenham’s algorithm is extended from 2-D to 3-D surface to enhance the probabilistic covering model for coverage measurement.A dynamic search strategy(DSS)is proposed to modify the artificial bee colony(ABC)and balance the exploration and exploitation ability for better convergence toward eliminating NP-hard deployment problems.Further,the cellular automata(CA)is utilized to enhance the convergence speed.The case study based on two typical FOI in the IWSN shows that the CA scheme effectively speeds up the optimization process.Comparative experiments are conducted on four benchmark functions to validate the effectiveness of the proposed method.The experimental results show that the proposed algorithm outperforms the ABC and gbest-guided ABC(GABC)algorithms.The results show that the proposed energy coverage optimization method based on the hybrid power bank deployment model generates more accurate results than the results obtained by similar algorithms(i.e.,ABC,GABC).The proposed model is,therefore,effective and efficient for optimization in the IWSN.展开更多
China's energy supply-and-demand model and two related carbon emission scenarios, including a planned peak scenario and an advanced peak scenario, are designed taking into consideration China's economic development,...China's energy supply-and-demand model and two related carbon emission scenarios, including a planned peak scenario and an advanced peak scenario, are designed taking into consideration China's economic development, technological progress, policies, resources, environmental capacity, and other factors. The analysis of the defined scenarios provides the following conclusions: Primary energy and power demand will continue to grow leading up to 2030, and the growth rate of power demand will be much higher than that of primary energy demand. Moreover, low carbonization will be a basic feature of energy supply-and-demand structural changes, and non-fossil energy will replace oil as the second largest energy source. Finally, energy- related carbon emissions could peak in 2025 through the application of more efficient energy consumption patterns and more low-carbon energy supply modes. The push toward decarbonization of the power industry is essential for reducing the peak value of carbon emissions.展开更多
Cells of in vitro cultured epidermis explants of ectoderm isolated at early gastrula stage,showed only weak excitability or even non-excitable at 6V when examined electrophysiologically.If non-excitable explants were ...Cells of in vitro cultured epidermis explants of ectoderm isolated at early gastrula stage,showed only weak excitability or even non-excitable at 6V when examined electrophysiologically.If non-excitable explants were treated with 100 mM glucose,the action potential (AP) appeared and within 1 hr reached its maximum.At the same time,their stimulus threshold became lowered gradually.And,if the glucose was washed out,AP gradually disappeared.If explants were treated with glucose of different concentrations,the percentage of explants which displayed AP increased with the increase of glucose concentration.When explants with approximately the same original stimulus threshold were treated with glucose of different concentrations,the stimulus threshold became lowered more in the more concentrated solution.If explants with different original stimulus thresholds were treated with glucose of the same concentration,the lowering of stimulus threshold was more obvious in those with higher original stimulus threshold.Other energy supplying substances used showed similar effect.展开更多
In considering of high proportion of renewable energy supply in 2050, the accelerating of energy consumption gross, source and environment can affect the energy system restrict affection are stronger. Add wind and sol...In considering of high proportion of renewable energy supply in 2050, the accelerating of energy consumption gross, source and environment can affect the energy system restrict affection are stronger. Add wind and solar to electricity energy with large amount of energy source exploitation. The energy source amount per person is lower. Considering the renewable energy amount and supply, primary energy storage and structure problem is standing out. Before the wide spread of renewable energy, Using the high-carbon energy in China can pollute seriously. Chinese energy supply and demand problem is research key point. This paper researches Chinese energy supply and demand pattern system and evaluation methodology, gives out the inner and outer influencing elements. And evaluate Chinese energy supply and demand pattern from energy gross, structure, distribution and transportation. Use energy supply synthesize radar comparison chart in certain time period. From energy security, economy, clean and efficiency, analyze the benefit comparisons of Chinese energy supply and demand pattern. This energy supply and demand pattern model will give one certain theoretical analysis and practice reference to the further high proportion of renewable energy.展开更多
The building sector is one of the largest energy user and carbon emitters globally.To increase the utilization rate of renewable energy and reduce carbon dioxide emissions,the optimal technical scheme of active public...The building sector is one of the largest energy user and carbon emitters globally.To increase the utilization rate of renewable energy and reduce carbon dioxide emissions,the optimal technical scheme of active public institutions and coupled utilization of renewable energy is studied.In this study,the energy consumption of three types of public institutions in various regions of China was simulated by using DeST building energy consumption software,combined with energy conversion efficiency and data released by the National Bureau of Statistics,and the total energy demand and total energy supply of public institutions were predicted using the load density method.Based on the coupling mechanism of the MARKAL model,the optimal proportion of renewable energy in the energy supply of public buildings in different regions is determined.Through the study of the number of public institutions in various regions of China,energy consumption characteristics,construction area,and other related data,the reverse energy flow method is creatively proposed,and the active and renewable energy coupling algorithm from the energy demand side of public institutions to the energy supply side is established.The results show that the central region has the highest utilization rate of renewable energy in the public sector,reaching 36.18%.The use of renewable energy in public buildings in hot summer and warm winter zones decreased to 35.08%,and it was 12.82% in cold zones.By 2025,the proportion of renewable energy resources in China is expected to reach 29.2%.The energy coupling model and algorithm constructed in this paper can provide a basis for the coupling macro configuration of renewable energy in public institutions in China.展开更多
Mobile edge computing(MEC),as a new distributed computing model,satisfies the low energy consumption and low latency requirements of computation-intensive services.The task offloading of MEC has become an important re...Mobile edge computing(MEC),as a new distributed computing model,satisfies the low energy consumption and low latency requirements of computation-intensive services.The task offloading of MEC has become an important research hotspot,as it solves the problems of insufficient computing capability and battery capacity of Internet of things(IoT)devices.This study investigates task offloading scheduling in a dynamic MEC system.By integrating energy harvesting technology into IoT devices,we propose a hybrid energy supply model.We jointly optimize local computing,offloading duration,and edge computing decisions to minimize system cost.On the basis of stochastic optimization theory,we design an online dynamic task offloading algorithm for MEC with a hybrid energy supply called DTOME.DTOME can make task offloading decisions by weighing system cost and queue stability.We quote dynamic programming theory to obtain the optimal task offloading strategy.Simulation results verify the effectiveness of DTOME,and show that DTOME entails lower system cost than two baseline task offloading strategies.展开更多
Efforts to provide alternative resources and technologies for producing liquid fuel have recently been intensified.Different levels of dependence on oil imports and carbon prices have a significant impact on the compo...Efforts to provide alternative resources and technologies for producing liquid fuel have recently been intensified.Different levels of dependence on oil imports and carbon prices have a significant impact on the composition of the cost-minimizing portfolio of technologies.Considering such factors,how should China plan its future liquid fuel industry?The model for supporting the technology portfolio and capacity configuration that minimizes the total system cost until 2045 is described in this study.The results obtained for different carbon prices and levels of dependence on oil import indicate that the oil-to-liquid fuel(OTL)will remain dominant in China's liquid fuel industry over the next three decades.If the carbon price is low,the coal-to-liquid fuel(CTL)process is competitive.For a high carbon price,the biomass-to-liquid fuel(BTL)technology expands more rapidly.The results also reveal that developing the BTL and CTL can effectively reduce the oil-import dependency;moreover,a high carbon price can lead to the CTL being replaced with the low-carbon technology(e.g.,BTL).Improvement in energy raw material conversion and application of CO_(2) removal technologies are also effective methods to control carbon emissions for achieving the carbon emission goals and ultimately emission reduction targets.展开更多
With the great advantages and continuous innovations,prolific research efforts have been devoted to the Stirling engine(SE)domain driven by the sustainability development.In this study,a bibliometric analysis is condu...With the great advantages and continuous innovations,prolific research efforts have been devoted to the Stirling engine(SE)domain driven by the sustainability development.In this study,a bibliometric analysis is conducted to explore the research tend and hotspots of SE.The country co-authorship,institute co-authorship and keyword networks are engendered from the visual map using VOSviewer,showing China ranks the first with the total number of published articles and the majority publications are presented by Chinese Academy of Sciences.Owing to the highest node centrality,the research findings in USA can be considered the most influential and greatly worthy being referred,particularly represented by the early contribution for thermo-acoustic SE.The total 7 keyword clusters are classified through the top terms in Citespace and 4 of them are related to its energy supply system,demonstrating the typical application of SE-based combined heat and power(CHP)and integrated multi-energy complementary system have gained much attention.Based on this,a detailed review of SE-based energy supply systems is further conducted through the system forms,4E performance evaluation and soft model combing optimization solutions.Several relevant issues hindering the improvement of these terms are summa-rized,providing the potential guides to help develop the SE-based energy supply system.展开更多
Under the general plan of Beijing approved in princi-ple by the State Council in 1983,considerable progress hasbeen made in the supply of electricity,central heating,gas,coal and so on in the past ten years.Neverthele...Under the general plan of Beijing approved in princi-ple by the State Council in 1983,considerable progress hasbeen made in the supply of electricity,central heating,gas,coal and so on in the past ten years.Nevertheless,due tothe rapid economic development and the enhancement ofthe living standard,shortages in the supply of electricity,thermal energy,gas and other high quality energy is still ob-vious.Meanwhile the constant increase in the amount展开更多
Wearable sensing systems,as a spearhead of artificial intelligence,are playing increasingly important roles in many fields especially health monitoring.In order to achieve a better wearable experience,rationally integ...Wearable sensing systems,as a spearhead of artificial intelligence,are playing increasingly important roles in many fields especially health monitoring.In order to achieve a better wearable experience,rationally integrating the two key components of sensing systems,that is,power supplies and sensors,has become a desperate requirement.However,limited by device designs and fabrication technologies,the current integrated sensing systems still face many great challenges,such as safety,miniaturization,mechanical stability,energyefficiency,sustainability,and comfortability.In this review,the key challenges and opportunities in the current development of integrated wearable sensing systems are summarized.By summarizing the typical configurations of diverse wearable power supplies,and recent advances concerning the integrated sensing systems driven by such power supplies,the representative integrated designs,and micro/nanofabrication technologies are highlighted.Lastly,some new directions and potential solutions aiming at the device-level integration designs are outlooked.展开更多
For many years, China has made great strides in constructing a sizeable and stable energy supply system rooted mainly in domestic coal supply. That system, however, is subject to immense strain as a result of rapid ec...For many years, China has made great strides in constructing a sizeable and stable energy supply system rooted mainly in domestic coal supply. That system, however, is subject to immense strain as a result of rapid economic growth, rising living standard, widespread environmental degradation, limited oil reserves and uneven resources distribution. Industrialization and urbanization since the early 1980s have imposed structural constraints on its traditional coal-based energy supply model. Eventually, China became a net oil-importer in 1993 when ten million tons of crude oil and petroleum products from abroad fed into the local economies of the coastal areas. Such a change meant that energy security has become an increasingly sensitive issue to the central government of China. This paper argues that China could benefit from a more open energy supply by striking to a balance of both domestic and international sources, rather than the traditional mode emphasized on a highly self-sufficiency rate.展开更多
In the summer of 2010/2011 Chile suffered the third most severe energy and water supply crisis in only one decade. This may be surprising as the Andes which accompany the country along 4,200 km are a water tower and c...In the summer of 2010/2011 Chile suffered the third most severe energy and water supply crisis in only one decade. This may be surprising as the Andes which accompany the country along 4,200 km are a water tower and could provide more electricity and water than needed. On top of that, it has to be mentioned that Chile also counts with sunny and windy climates and with excellent geothermal energy resources and thus has a huge potential as far as renewable energies are concerned. After analyzing the existing natural conditions, the infrastructure and the present challenges of climate change, it has to be asked in which way Chile can make use of this potential in the near future, considering the legal and political situation and the technological opportunities. It seems that the resources are still hidden in the Andes, and only the key is missing to realize the country's natural potential. This research has been based on the analysis of existing literature, media, quantitative data from government institutions and other antecedents obtained by the authors in field work done in the South of Chile in 2OLO. The added value of this compilation lies in the comprehensive perspective, linking the knowledge of climatologists, hydrologists, mountain researchers and energy experts in order to support a sustainable energy and water supply for the future in Chile. From this present research, it can be concluded that Chile necessarilyhas to adopt new energy-related strategies, particularly those aimed at diminishing the strong dependence on traditional sources of energy and establishing new techniques and technologies for generating electrieity and utilizing the vast potential that the country is ready to offer, such as that provided by the Andes along 4,200 kilometers.展开更多
This paper presents the results of a combined study of building energy consumption and the electricity production from PV modules integrated into a shading device, taking account of different site layouts. Various com...This paper presents the results of a combined study of building energy consumption and the electricity production from PV modules integrated into a shading device, taking account of different site layouts. Various combinations of surrounding building configurations and the tilt angles of the shading device (that determines the PV module orientation) are examined.展开更多
Natural gas is one of the key energy resources for Turkey due to fact that 32% of annual primary energy supply and 45% of annual electricity production is obtained from natural gas with also common usage of residentia...Natural gas is one of the key energy resources for Turkey due to fact that 32% of annual primary energy supply and 45% of annual electricity production is obtained from natural gas with also common usage of residential and industrial zones. In this study, the supply security of natural gas was taken into consideration with strategic criteria of energy policy with the SWOT (strengths, weaknesses, opportunities and threats) analysis and the future projection for Turkey. It has been concluded on geopolitics criteria, domestic production and research for resources must be stimulated as high as possible and participation to abroad resources must be implemented.展开更多
The development of renewable woods for power generation can help improve the energy efficiency of buildings,and promote the concept design and implementation of“smart buildings”.Here,with specific chemical treatment...The development of renewable woods for power generation can help improve the energy efficiency of buildings,and promote the concept design and implementation of“smart buildings”.Here,with specific chemical treatment and hydrothermal synthesis,we demonstrated the practical value of natural wood for thermoelectric power generation in smart buildings.The prepared wood-based thermoelectric sponges show high Seebeck coefficients of 320.5 and 436.6μV/K in the vertical and parallel directions of the longitudinal channel of wood.After 500 cycles of the compressive strain at 20%,the corresponding Seebeck coefficients increase up to 413.4 and 502.1μV/K,respectively,which is attributed to the improved contact and connection between tellurium thermoelectric nanowires.The Seebeck coefficients are much larger than those of most reported inorganic thermoelectric materials.Meanwhile,the thermoelectric sponges maintain excellent thermoelectric and mechanical stability.We further modeled the application value of wood-based thermoelectric sponges in smart buildings for power generation.Relatively high thermoelectric electricity can be obtained,such as in Beijing with over 1.5 million kWh every year,demonstrating the great potential in thermal energy harvest and energy supply.展开更多
The universal mathematical model of an engine is established,and an economical zone,in which an engine mainly provides medium output load at medium speed,is presented.Based on the experimental data and the universal m...The universal mathematical model of an engine is established,and an economical zone,in which an engine mainly provides medium output load at medium speed,is presented.Based on the experimental data and the universal model of such an engine above,a mathematical model of a refitted engine is provided.The boundary of the corresponding economical zone is further demarcated,and the optimal operating curve and the operating point of the engine are analyzed.Then,the energy transforming models of the power system are established in the mode of cooling,heating and power(MCHP),the mode of heating and power(MHP)and the mode of electricity powering(MEP).The parameter matching of the power system is optimized according to the transmission ratios of the gear box in the power distribution system.The results show that,in the MCHP,the speed transmission ratio of the engine to the gear box(ies)and the speed transmission ratio of the motor to the gear box(ims)are defined as 2.9 and 1,respectively;in the MHP,when the demand load of the power system is less than the low critical load of the economical zone,the speed transmission ratio of the motor to the engine(ime)is equal to 1,and when the demand load of the power system exceeds the low critical load of the economical zone,ime equals 0.85;in the MEP,the optimal value of ims is defined as 2.5.展开更多
A circular and sustainable economy for the private transport sector requires a holistic view of the emitted CO_(2) emissions.Looking at the energy supplied to the vehicle in terms of a circular economy leads to defoss...A circular and sustainable economy for the private transport sector requires a holistic view of the emitted CO_(2) emissions.Looking at the energy supplied to the vehicle in terms of a circular economy leads to defossilisation.The remaining energy sources or forms are renewable electric energy,green hydrogen and renewable fuels.A holistic view of the CO_(2) emissions of these energy sources and forms and the resulting powertrain technologies must take into account all cradle-to-grave emissions for both the vehicle and the energy supply.In order to compare the different forms of energy,the three most relevant forms of powertrain technology are considered and a configuration is chosen that allows for an appropriate comparison.For this purpose,data from the FVV project“Powertrain 2040”are used[1]and combined with research data on the energy supply chain for passenger cars.The three comparable powertrain configurations are a battery electric vehicle,a fuel cell electric vehicle and an internal combustion engine hybrid vehicle fueled with electric fuel.First,the three selected powertrain configurations are presented in terms of their performance,weight,technology and other characteristics.A comparative analysis is carried out for different CO_(2) emissions of the electricity mix.The electricity mix is used for both the production of the vehicle and the energy.The results are presented in the form of cradle-to-wheel emissions,which consider the total CO_(2) emissions of the vehicle over its life cycle.Finally,the results are analyzed and discussed to determine which powertrain technology fits best into which energy sector CO_(2) emissions window.展开更多
In this paper,we investigate the effective deployment of millimeter wave(mmWave)in unmanned aerial vehicle(UAV)-enabled wireless powered communication network(WPCN).In particular,a novel framework for optimizing the p...In this paper,we investigate the effective deployment of millimeter wave(mmWave)in unmanned aerial vehicle(UAV)-enabled wireless powered communication network(WPCN).In particular,a novel framework for optimizing the performance of such UAV-enabled WPCN in terms of system throughput is proposed.In the considered model,multiple UAVs monitor in the air along the scheduled flight trajectory and transmit monitoring data to micro base stations(mBSs)with the harvested energy via mmWave.In this case,we propose an algorithm for jointly optimizing transmit power and energy transfer time.To solve the non-convex optimization problem with tightly coupled variables,we decouple the problem into more tractable subproblems.By leveraging successive convex approximation(SCA)and block coordinate descent techniques,the optimal solution is obtained by designing a two-stage joint iteration optimization algorithm.Simulation results show that the proposed algorithm with joint transmit power and energy transfer time optimization achieves significant performance gains over Q-learning method and other benchmark schemes.展开更多
After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust he...After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data: distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV (photovoltaic) panel, PCM (phase change material), thermal storage, FCU (fan coil unit) and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.展开更多
基金Fundings that permitted this research were granted by Australia CRC for Low Carbon Living through the Project“Integrated Carbon Metrics(ICM)”(RP2007)the National Natural Science Foundation of China(51908064)the Natural Science Foundation of Hunan Province(2021JJ30717).
文摘The rapid growth of distributed renewable energy penetration is promoting the evolution of the energy system toward decentralization and decentralized and digitized smart grids.This study was based on energy blockchain,and developed a dual-biding mechanism based on the real-time energy surplus and demand in the local smart grid,which is expected to enable reliable,affordable,and clean energy supply in smart communities.In the proposed system,economic benefits could be achieved by replacing fossil-fuel-based electricity with the high penetration of affordable solar PV electricity.The reduction of energy surplus realized by distributed energy production and P2P energy trading,within the smart grid results in less transmission loss and lower requirements for costly upgrading of existing grids.By adopting energy blockchain and smart contract technologies,energy secure trading with a low risk of privacy leakage could be accommodated.The prototype is examined through a case study,and the feasibility and efficiency of the proposed mechanism are further validated by scenario analysis.
文摘Energy supply is one of the most critical challenges of wireless sensor networks(WSNs)and industrial wireless sensor networks(IWSNs).While research on coverage optimization problem(COP)centers on the network’s monitoring coverage,this research focuses on the power banks’energy supply coverage.The study of 2-D and 3-D spaces is typical in IWSN,with the realistic environment being more complex with obstacles(i.e.,machines).A 3-D surface is the field of interest(FOI)in this work with the established hybrid power bank deployment model for the energy supply COP optimization of IWSN.The hybrid power bank deployment model is highly adaptive and flexible for new or existing plants already using the IWSN system.The model improves the power supply to a more considerable extent with the least number of power bank deployments.The main innovation in this work is the utilization of a more practical surface model with obstacles and training while improving the convergence speed and quality of the heuristic algorithm.An overall probabilistic coverage rate analysis of every point on the FOI is provided,not limiting the scope to target points or areas.Bresenham’s algorithm is extended from 2-D to 3-D surface to enhance the probabilistic covering model for coverage measurement.A dynamic search strategy(DSS)is proposed to modify the artificial bee colony(ABC)and balance the exploration and exploitation ability for better convergence toward eliminating NP-hard deployment problems.Further,the cellular automata(CA)is utilized to enhance the convergence speed.The case study based on two typical FOI in the IWSN shows that the CA scheme effectively speeds up the optimization process.Comparative experiments are conducted on four benchmark functions to validate the effectiveness of the proposed method.The experimental results show that the proposed algorithm outperforms the ABC and gbest-guided ABC(GABC)algorithms.The results show that the proposed energy coverage optimization method based on the hybrid power bank deployment model generates more accurate results than the results obtained by similar algorithms(i.e.,ABC,GABC).The proposed model is,therefore,effective and efficient for optimization in the IWSN.
文摘China's energy supply-and-demand model and two related carbon emission scenarios, including a planned peak scenario and an advanced peak scenario, are designed taking into consideration China's economic development, technological progress, policies, resources, environmental capacity, and other factors. The analysis of the defined scenarios provides the following conclusions: Primary energy and power demand will continue to grow leading up to 2030, and the growth rate of power demand will be much higher than that of primary energy demand. Moreover, low carbonization will be a basic feature of energy supply-and-demand structural changes, and non-fossil energy will replace oil as the second largest energy source. Finally, energy- related carbon emissions could peak in 2025 through the application of more efficient energy consumption patterns and more low-carbon energy supply modes. The push toward decarbonization of the power industry is essential for reducing the peak value of carbon emissions.
文摘Cells of in vitro cultured epidermis explants of ectoderm isolated at early gastrula stage,showed only weak excitability or even non-excitable at 6V when examined electrophysiologically.If non-excitable explants were treated with 100 mM glucose,the action potential (AP) appeared and within 1 hr reached its maximum.At the same time,their stimulus threshold became lowered gradually.And,if the glucose was washed out,AP gradually disappeared.If explants were treated with glucose of different concentrations,the percentage of explants which displayed AP increased with the increase of glucose concentration.When explants with approximately the same original stimulus threshold were treated with glucose of different concentrations,the stimulus threshold became lowered more in the more concentrated solution.If explants with different original stimulus thresholds were treated with glucose of the same concentration,the lowering of stimulus threshold was more obvious in those with higher original stimulus threshold.Other energy supplying substances used showed similar effect.
文摘In considering of high proportion of renewable energy supply in 2050, the accelerating of energy consumption gross, source and environment can affect the energy system restrict affection are stronger. Add wind and solar to electricity energy with large amount of energy source exploitation. The energy source amount per person is lower. Considering the renewable energy amount and supply, primary energy storage and structure problem is standing out. Before the wide spread of renewable energy, Using the high-carbon energy in China can pollute seriously. Chinese energy supply and demand problem is research key point. This paper researches Chinese energy supply and demand pattern system and evaluation methodology, gives out the inner and outer influencing elements. And evaluate Chinese energy supply and demand pattern from energy gross, structure, distribution and transportation. Use energy supply synthesize radar comparison chart in certain time period. From energy security, economy, clean and efficiency, analyze the benefit comparisons of Chinese energy supply and demand pattern. This energy supply and demand pattern model will give one certain theoretical analysis and practice reference to the further high proportion of renewable energy.
基金supported by National Natural Science Funds(52078308)Liao Ning Revitalization Talents Program(XLYC2007003)the Educational Commission of Liaoning Province of China(lnzd202003).
文摘The building sector is one of the largest energy user and carbon emitters globally.To increase the utilization rate of renewable energy and reduce carbon dioxide emissions,the optimal technical scheme of active public institutions and coupled utilization of renewable energy is studied.In this study,the energy consumption of three types of public institutions in various regions of China was simulated by using DeST building energy consumption software,combined with energy conversion efficiency and data released by the National Bureau of Statistics,and the total energy demand and total energy supply of public institutions were predicted using the load density method.Based on the coupling mechanism of the MARKAL model,the optimal proportion of renewable energy in the energy supply of public buildings in different regions is determined.Through the study of the number of public institutions in various regions of China,energy consumption characteristics,construction area,and other related data,the reverse energy flow method is creatively proposed,and the active and renewable energy coupling algorithm from the energy demand side of public institutions to the energy supply side is established.The results show that the central region has the highest utilization rate of renewable energy in the public sector,reaching 36.18%.The use of renewable energy in public buildings in hot summer and warm winter zones decreased to 35.08%,and it was 12.82% in cold zones.By 2025,the proportion of renewable energy resources in China is expected to reach 29.2%.The energy coupling model and algorithm constructed in this paper can provide a basis for the coupling macro configuration of renewable energy in public institutions in China.
基金This work was partly supported by the National Natural Science Foundation of China(Nos.61902029 and 61872044)R&D Program of Beijing Municipal Education Commission(No.KM202011232015).
文摘Mobile edge computing(MEC),as a new distributed computing model,satisfies the low energy consumption and low latency requirements of computation-intensive services.The task offloading of MEC has become an important research hotspot,as it solves the problems of insufficient computing capability and battery capacity of Internet of things(IoT)devices.This study investigates task offloading scheduling in a dynamic MEC system.By integrating energy harvesting technology into IoT devices,we propose a hybrid energy supply model.We jointly optimize local computing,offloading duration,and edge computing decisions to minimize system cost.On the basis of stochastic optimization theory,we design an online dynamic task offloading algorithm for MEC with a hybrid energy supply called DTOME.DTOME can make task offloading decisions by weighing system cost and queue stability.We quote dynamic programming theory to obtain the optimal task offloading strategy.Simulation results verify the effectiveness of DTOME,and show that DTOME entails lower system cost than two baseline task offloading strategies.
基金National Natural Science Foundation of China(grant numbers 71961137012,71874055)National Science Centre,Poland(2018/30/Q/HS4/00764)research support by the Energy,Climate and Environment Program of International Institute for Applied System Analysis(IIASA)within the Young Scientists Summer Program(YSSP).
文摘Efforts to provide alternative resources and technologies for producing liquid fuel have recently been intensified.Different levels of dependence on oil imports and carbon prices have a significant impact on the composition of the cost-minimizing portfolio of technologies.Considering such factors,how should China plan its future liquid fuel industry?The model for supporting the technology portfolio and capacity configuration that minimizes the total system cost until 2045 is described in this study.The results obtained for different carbon prices and levels of dependence on oil import indicate that the oil-to-liquid fuel(OTL)will remain dominant in China's liquid fuel industry over the next three decades.If the carbon price is low,the coal-to-liquid fuel(CTL)process is competitive.For a high carbon price,the biomass-to-liquid fuel(BTL)technology expands more rapidly.The results also reveal that developing the BTL and CTL can effectively reduce the oil-import dependency;moreover,a high carbon price can lead to the CTL being replaced with the low-carbon technology(e.g.,BTL).Improvement in energy raw material conversion and application of CO_(2) removal technologies are also effective methods to control carbon emissions for achieving the carbon emission goals and ultimately emission reduction targets.
基金This work is supported by National Natural Science Foundation of China(Project No.52006114)BIT Research and Innovation Pro-moting Project(Grant No.2022YCXZ005).
文摘With the great advantages and continuous innovations,prolific research efforts have been devoted to the Stirling engine(SE)domain driven by the sustainability development.In this study,a bibliometric analysis is conducted to explore the research tend and hotspots of SE.The country co-authorship,institute co-authorship and keyword networks are engendered from the visual map using VOSviewer,showing China ranks the first with the total number of published articles and the majority publications are presented by Chinese Academy of Sciences.Owing to the highest node centrality,the research findings in USA can be considered the most influential and greatly worthy being referred,particularly represented by the early contribution for thermo-acoustic SE.The total 7 keyword clusters are classified through the top terms in Citespace and 4 of them are related to its energy supply system,demonstrating the typical application of SE-based combined heat and power(CHP)and integrated multi-energy complementary system have gained much attention.Based on this,a detailed review of SE-based energy supply systems is further conducted through the system forms,4E performance evaluation and soft model combing optimization solutions.Several relevant issues hindering the improvement of these terms are summa-rized,providing the potential guides to help develop the SE-based energy supply system.
文摘Under the general plan of Beijing approved in princi-ple by the State Council in 1983,considerable progress hasbeen made in the supply of electricity,central heating,gas,coal and so on in the past ten years.Nevertheless,due tothe rapid economic development and the enhancement ofthe living standard,shortages in the supply of electricity,thermal energy,gas and other high quality energy is still ob-vious.Meanwhile the constant increase in the amount
基金GRF,Hong Kong,Grant/Award Number:CityU 11305218Natural Science Foundation of Guangdong Province,Grant/Award Number:2019A1515011819Songshan Lake Materials Laboratory grant,Grant/Award Number:Y8D1041Z111。
文摘Wearable sensing systems,as a spearhead of artificial intelligence,are playing increasingly important roles in many fields especially health monitoring.In order to achieve a better wearable experience,rationally integrating the two key components of sensing systems,that is,power supplies and sensors,has become a desperate requirement.However,limited by device designs and fabrication technologies,the current integrated sensing systems still face many great challenges,such as safety,miniaturization,mechanical stability,energyefficiency,sustainability,and comfortability.In this review,the key challenges and opportunities in the current development of integrated wearable sensing systems are summarized.By summarizing the typical configurations of diverse wearable power supplies,and recent advances concerning the integrated sensing systems driven by such power supplies,the representative integrated designs,and micro/nanofabrication technologies are highlighted.Lastly,some new directions and potential solutions aiming at the device-level integration designs are outlooked.
基金Undertheauspicesof the National Natural Science FoundationofChina(No.90210037)
文摘For many years, China has made great strides in constructing a sizeable and stable energy supply system rooted mainly in domestic coal supply. That system, however, is subject to immense strain as a result of rapid economic growth, rising living standard, widespread environmental degradation, limited oil reserves and uneven resources distribution. Industrialization and urbanization since the early 1980s have imposed structural constraints on its traditional coal-based energy supply model. Eventually, China became a net oil-importer in 1993 when ten million tons of crude oil and petroleum products from abroad fed into the local economies of the coastal areas. Such a change meant that energy security has become an increasingly sensitive issue to the central government of China. This paper argues that China could benefit from a more open energy supply by striking to a balance of both domestic and international sources, rather than the traditional mode emphasized on a highly self-sufficiency rate.
文摘In the summer of 2010/2011 Chile suffered the third most severe energy and water supply crisis in only one decade. This may be surprising as the Andes which accompany the country along 4,200 km are a water tower and could provide more electricity and water than needed. On top of that, it has to be mentioned that Chile also counts with sunny and windy climates and with excellent geothermal energy resources and thus has a huge potential as far as renewable energies are concerned. After analyzing the existing natural conditions, the infrastructure and the present challenges of climate change, it has to be asked in which way Chile can make use of this potential in the near future, considering the legal and political situation and the technological opportunities. It seems that the resources are still hidden in the Andes, and only the key is missing to realize the country's natural potential. This research has been based on the analysis of existing literature, media, quantitative data from government institutions and other antecedents obtained by the authors in field work done in the South of Chile in 2OLO. The added value of this compilation lies in the comprehensive perspective, linking the knowledge of climatologists, hydrologists, mountain researchers and energy experts in order to support a sustainable energy and water supply for the future in Chile. From this present research, it can be concluded that Chile necessarilyhas to adopt new energy-related strategies, particularly those aimed at diminishing the strong dependence on traditional sources of energy and establishing new techniques and technologies for generating electrieity and utilizing the vast potential that the country is ready to offer, such as that provided by the Andes along 4,200 kilometers.
文摘This paper presents the results of a combined study of building energy consumption and the electricity production from PV modules integrated into a shading device, taking account of different site layouts. Various combinations of surrounding building configurations and the tilt angles of the shading device (that determines the PV module orientation) are examined.
文摘Natural gas is one of the key energy resources for Turkey due to fact that 32% of annual primary energy supply and 45% of annual electricity production is obtained from natural gas with also common usage of residential and industrial zones. In this study, the supply security of natural gas was taken into consideration with strategic criteria of energy policy with the SWOT (strengths, weaknesses, opportunities and threats) analysis and the future projection for Turkey. It has been concluded on geopolitics criteria, domestic production and research for resources must be stimulated as high as possible and participation to abroad resources must be implemented.
基金the National Key R&D Program of China(No.2020YFA0711500)the National Natural Science Fund of China(Nos.51973095,52273248,and 52303238)the Key Project of Natural Science Foundation of Tianjin City(No.21JCZDJC00010).
文摘The development of renewable woods for power generation can help improve the energy efficiency of buildings,and promote the concept design and implementation of“smart buildings”.Here,with specific chemical treatment and hydrothermal synthesis,we demonstrated the practical value of natural wood for thermoelectric power generation in smart buildings.The prepared wood-based thermoelectric sponges show high Seebeck coefficients of 320.5 and 436.6μV/K in the vertical and parallel directions of the longitudinal channel of wood.After 500 cycles of the compressive strain at 20%,the corresponding Seebeck coefficients increase up to 413.4 and 502.1μV/K,respectively,which is attributed to the improved contact and connection between tellurium thermoelectric nanowires.The Seebeck coefficients are much larger than those of most reported inorganic thermoelectric materials.Meanwhile,the thermoelectric sponges maintain excellent thermoelectric and mechanical stability.We further modeled the application value of wood-based thermoelectric sponges in smart buildings for power generation.Relatively high thermoelectric electricity can be obtained,such as in Beijing with over 1.5 million kWh every year,demonstrating the great potential in thermal energy harvest and energy supply.
基金The Natural Science Foundation of Jiangsu Higher Education Institutions of China(No.2009112TSJ0124)
文摘The universal mathematical model of an engine is established,and an economical zone,in which an engine mainly provides medium output load at medium speed,is presented.Based on the experimental data and the universal model of such an engine above,a mathematical model of a refitted engine is provided.The boundary of the corresponding economical zone is further demarcated,and the optimal operating curve and the operating point of the engine are analyzed.Then,the energy transforming models of the power system are established in the mode of cooling,heating and power(MCHP),the mode of heating and power(MHP)and the mode of electricity powering(MEP).The parameter matching of the power system is optimized according to the transmission ratios of the gear box in the power distribution system.The results show that,in the MCHP,the speed transmission ratio of the engine to the gear box(ies)and the speed transmission ratio of the motor to the gear box(ims)are defined as 2.9 and 1,respectively;in the MHP,when the demand load of the power system is less than the low critical load of the economical zone,the speed transmission ratio of the motor to the engine(ime)is equal to 1,and when the demand load of the power system exceeds the low critical load of the economical zone,ime equals 0.85;in the MEP,the optimal value of ims is defined as 2.5.
文摘A circular and sustainable economy for the private transport sector requires a holistic view of the emitted CO_(2) emissions.Looking at the energy supplied to the vehicle in terms of a circular economy leads to defossilisation.The remaining energy sources or forms are renewable electric energy,green hydrogen and renewable fuels.A holistic view of the CO_(2) emissions of these energy sources and forms and the resulting powertrain technologies must take into account all cradle-to-grave emissions for both the vehicle and the energy supply.In order to compare the different forms of energy,the three most relevant forms of powertrain technology are considered and a configuration is chosen that allows for an appropriate comparison.For this purpose,data from the FVV project“Powertrain 2040”are used[1]and combined with research data on the energy supply chain for passenger cars.The three comparable powertrain configurations are a battery electric vehicle,a fuel cell electric vehicle and an internal combustion engine hybrid vehicle fueled with electric fuel.First,the three selected powertrain configurations are presented in terms of their performance,weight,technology and other characteristics.A comparative analysis is carried out for different CO_(2) emissions of the electricity mix.The electricity mix is used for both the production of the vehicle and the energy.The results are presented in the form of cradle-to-wheel emissions,which consider the total CO_(2) emissions of the vehicle over its life cycle.Finally,the results are analyzed and discussed to determine which powertrain technology fits best into which energy sector CO_(2) emissions window.
文摘In this paper,we investigate the effective deployment of millimeter wave(mmWave)in unmanned aerial vehicle(UAV)-enabled wireless powered communication network(WPCN).In particular,a novel framework for optimizing the performance of such UAV-enabled WPCN in terms of system throughput is proposed.In the considered model,multiple UAVs monitor in the air along the scheduled flight trajectory and transmit monitoring data to micro base stations(mBSs)with the harvested energy via mmWave.In this case,we propose an algorithm for jointly optimizing transmit power and energy transfer time.To solve the non-convex optimization problem with tightly coupled variables,we decouple the problem into more tractable subproblems.By leveraging successive convex approximation(SCA)and block coordinate descent techniques,the optimal solution is obtained by designing a two-stage joint iteration optimization algorithm.Simulation results show that the proposed algorithm with joint transmit power and energy transfer time optimization achieves significant performance gains over Q-learning method and other benchmark schemes.
文摘After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data: distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV (photovoltaic) panel, PCM (phase change material), thermal storage, FCU (fan coil unit) and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.