Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and t...Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and the charge-carrier transporting layers plays a crucial role in undermining the stability of PSCs.In this work,we propose a strategy to stabilize high-performance PSCs with PCE over 23%by introducing a cesium-doped graphene oxide(GO-Cs)as an interlayer between the perovskite and hole-transporting material.The GO-Cs treated PSCs exhibit excellent operational stability with a projected T80(the time where the device PCE reduces to 80%of its initial value)of 2143 h of operation at the maximum powering point under one sun illumination.展开更多
In this study,we introduce a novel multi-objective optimization model tailored for modern manufacturing,aiming to mitigate the cost impacts of operational disruptions through optimized corrective maintenance.Central t...In this study,we introduce a novel multi-objective optimization model tailored for modern manufacturing,aiming to mitigate the cost impacts of operational disruptions through optimized corrective maintenance.Central to our approach is the strategic placement of maintenance stations and the efficient allocation of personnel,addressing a crucial gap in the integration of maintenance personnel dispatching and station selection.Our model uniquely combines the spatial distribution of machinery with the expertise of operators to achieve a harmonious balance between maintenance efficiency and cost-effectiveness.The core of our methodology is the NSGA Ⅲ+Dispatch,an advanced adaptation of the Non-Dominated Sorting Genetic Algorithm Ⅲ(NSGA-Ⅲ),meticulously designed for the selection of maintenance stations and effective operator dispatching.This method integrates a comprehensive coding process,crossover operator,and mutation operator to efficiently manage multiple objectives.Rigorous empirical testing,including a detailed analysis from a taiwan region electronic equipment manufacturer,validated the effectiveness of our approach across various scenarios of machine failure frequencies and operator configurations.The findings reveal that the proposed model significantly outperforms current practices by reducing response times by up to 23%in low-frequency and 28.23%in high-frequency machine failure scenarios,leading to notable improvements in efficiency and cost reduction.Additionally,it demonstrates significant improvements in oper-ational efficiency,particularly in selective high-frequency failure contexts,while ensuring substantial manpower cost savings without compromising on operational effectiveness.This research significantly advances maintenance strategies in production environments,providing the manufacturing industry with practical,optimized solutions for diverse machine malfunction situations.Furthermore,the methodologies and principles developed in this study have potential applications in various other sectors,including healthcare,transportation,and energy,where maintenance efficiency and resource optimization are equally critical.展开更多
During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil d...During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation.展开更多
In the process of designing a municipal rainwater and sewage pumping station,it is necessary to accurately grasp the design points,reasonably determine the scale of the rainwater and sewage pumping station,scientifica...In the process of designing a municipal rainwater and sewage pumping station,it is necessary to accurately grasp the design points,reasonably determine the scale of the rainwater and sewage pumping station,scientifically select the location and layout,and select materials reasonably.After completing the process design of the municipal rainwater and sewage pumping station and putting it into operation,in order to ensure the normal and stable operation of the pumping station,it is necessary to focus on strengthening the operation and management of diving equipment,cleaning equipment,and electromechanical equipment.The author analyzes the key points and specific design path of the process design of municipal rainwater and sewage pumping stations,and puts forward effective strategies for operation management,hoping to contribute to the scientific design and stable operation of municipal rainwater and sewage pumping stations.展开更多
Through investigation and analysis on typical system of pumped-storage stations built in China, this paper approaches the investment andfinancing policies, electricity pricing policies and management modes for suchsta...Through investigation and analysis on typical system of pumped-storage stations built in China, this paper approaches the investment andfinancing policies, electricity pricing policies and management modes for suchstations. In order to find out the actual operation situations, eight pumped-storage stations in five provinces (municipality) were investigated, and analysesand calculations were carried out on their investments, benefits, capabilities ofloan-repaying etc. During the investigation and study, the types and the installedcapacities of the stations were paid close attention to, so they were made morerepresentative to reflect the present situation of pumped-storage stations inrespect of construction and operation.展开更多
In China,operational in-situ marine monitoring is the primary means of directly obtaining hydrological,meteorological,and oceanographic environmental parameters across sea areas,and it is essential for applications su...In China,operational in-situ marine monitoring is the primary means of directly obtaining hydrological,meteorological,and oceanographic environmental parameters across sea areas,and it is essential for applications such as forecast of marine environment,prevention and mitigation of disaster,exploitation of marine resources,marine environmental protection,and management of transportation safety.In this paper,we summarise the composition,development courses,and present operational status of three systems of operational in-situ marine monitoring,namely coastal marine automated network station,ocean data buoy and voluntary observing ship measuring and reporting system.Additionally,we discuss the technical development in these in-situ systems and achievements in the key generic technologies along with future development trends.展开更多
Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjus...Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjustable blade, mathematical models of pumping station optimal operation are established and solved with genetic algorithm. For different total pumping discharge and total pumping volume of water per day, in order to minimize pumping station operation cost, the number and operation duties of running pump units are respectively determined at different periods of time in a day. The results indicate that the saving of electrical cost is significantly effected by the schemes of adjusting blade angles and time-varying electrical price when pumping certain water volume of water per day, and compared with conventional operation schemes （namely, the schemes of pumping station operation at design blade angles based on certain pumping discharge）, the electrical cost is saved by 4.73%-31.27%. Also, compared with the electrical cost of conventional operation schemes, the electrical cost is saved by 2.03%-5.79% by the schemes of adjusting blade angles when pumping certain discharge.展开更多
The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode...The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode of the two can better meet the needs of the electric power system. This article first presents an analysis of the necessity and superiority of such mode, then explains its meaning and analyzes the working routes. Finally, it proposes the business modes as follows: low price pumping water electricity plus nuclear power in the near term;nuclear power shifted to pumped storage power participating in market competition in the middle term;and, in the long term, nuclear power shifted to pumped storage power as primary and serving as an electric power system when needed.展开更多
Toward solving the actual operation problems of cascade hydropower stations under hydrologic uncertainty, this paper presents the process of extraction of statistical characteristics from long-term optimal cascade ope...Toward solving the actual operation problems of cascade hydropower stations under hydrologic uncertainty, this paper presents the process of extraction of statistical characteristics from long-term optimal cascade operation, and proposes a monthly operation function algorithm for the actual operation of cascade hydropower stations through the identification, processing, and screening of available information during long-term optimal operation. Applying the operation function to the cascade hydropower stations on the Jinshajiang-Yangtze River system, the modeled long-term electric generation is shown to have high precision and provide benefits. Through comparison with optimal operation, the simulation results show that the operation function proposed retains the characteristics of optimal operation. Also, the inadequacies and attribution of the algorithm are discussed based on case study, providing decision support and reference information for research on large-scale cascade operation work.展开更多
[Objective] The aim was to study the development and application of operation in comprehensive platform of professional meteorological station.[Method] Taking the operation platform of professional meteorological stat...[Objective] The aim was to study the development and application of operation in comprehensive platform of professional meteorological station.[Method] Taking the operation platform of professional meteorological station in Yantai City as an example,and by dint of VB language and Mysql database technology,the ideas of comprehensive platform development of operation in professional meteorological station,main contents of the platform and its main functions were introduced.[Result] The platform mainly used VB language and Mysql database technology.Gathering together the forecast making,forecast inventory and check,surveillance of data uploading and machine operation and records of shifts,the interface was simple,visual and easy to handle.It reduced reporters’ workload,improved their work efficiency and was the favorite of majority reporters.[Conclusion] The study provided reference for the improvement of work efficiency of each professional meteorological station.展开更多
Traditional optimal operation of hydropower station usually has two problems. One is that the optimal algorithm hasn’t high efficiency, and the other is that the optimal operation model pays little attention to ecolo...Traditional optimal operation of hydropower station usually has two problems. One is that the optimal algorithm hasn’t high efficiency, and the other is that the optimal operation model pays little attention to ecology. And with the development of electric power market, the generated benefit is concerned instead of generated energy. Based on the analysis of time-varying electricity price policy, an optimal operation model of hydropower station reservoir with ecology consideration is established. The model takes the maximum annual power generation benefit, the maximum output of the minimal output stage in the year and the minimum shortage of eco-environment demand as the objectives, and reservoir water quantity balance, reservoir storage capacity, reservoir discharge flow and hydropower station output and nonnegative variable as the constraints. To solve the optimal model, a chaotic optimization genetic algorithm which combines the ergodicity of chaos and the inversion property of genetic algorithm is exploited. An example is given, which shows that the proposed model and algorithm are scientific and feasible to deal with the optimal operation of hydropower station.展开更多
On March 31, in accordance with the typical design requirements of the State Grid, the f irst large electric vehicle (EV) charging station, built by the North China Grid,
An operation strategy of the electric vehicle （EV） battery charging and swapping station is proposed in the paper. The strategy is established based on comprehensively consideration of the EV charging behaviors and ...An operation strategy of the electric vehicle （EV） battery charging and swapping station is proposed in the paper. The strategy is established based on comprehensively consideration of the EV charging behaviors and the possible mutual actions between battery charging and swapping. Three energy management strategies can be used in the station： charging period shifting, energy exchange between EVs, and energy supporting from surplus swapping batteries. Then an optimization model which minimizes the total energy management costs of the station is built. The Monte Carlo simulation is applied to analyze the characteristics of the EV battery charging load, and a heuristic algorithm is used to solve the strategy providing the relevant information of EVs and the battery charging and swapping station. The operation strategy can efficiently reduce battery charging during the high electricity price periods and make more reasonable use of the resources. Simulations prove the feasibility and rationality of the strategy.展开更多
In the paper,an operational program of electric bus charging station is proposed,which is special for "The Construction Project for Expo 2010 Temporary Electric Bus Charging Station".Based on the quick-chang...In the paper,an operational program of electric bus charging station is proposed,which is special for "The Construction Project for Expo 2010 Temporary Electric Bus Charging Station".Based on the quick-change mode,a vehicle operating schedule model has been established to meet the capacity of transport.Then,according to the quantity of passengers and utilization of batteries,a calculative method of parameters,such as the number of spare batteries and bus departure rules,has been provided.Furthermore,optimal simulation software designed for operating process of the charging station has been identified incorporating actual running data from electric buses and monitoring system of the charging station,and the rationality of the design is verified in the preliminary commissioning and the official operation.展开更多
The paper outlines the Yangtze Three Gorges water conservancy complex. It describes the power transmission and distribution equipment in the Three Gorges LeftBank Hydropower Station, especially large high-voltage dist...The paper outlines the Yangtze Three Gorges water conservancy complex. It describes the power transmission and distribution equipment in the Three Gorges LeftBank Hydropower Station, especially large high-voltage distribution devices. It elaborates the measures for suppressing GIS over-voltage and the tests on VFTO, besides technical measures to ensure safety and stability of power system in the station. It also makes some analyses and summaries about the problems encountered in operation of the equipment.展开更多
Real-time kinematic GPS precise positioning has been playing an increasing role in both surveying and navigation. Based on the city’s fibre LAN network, Shenzhen Continuous Operating Reference Stations (SZCORS) syste...Real-time kinematic GPS precise positioning has been playing an increasing role in both surveying and navigation. Based on the city’s fibre LAN network, Shenzhen Continuous Operating Reference Stations (SZCORS) system has been established and consists of GPS reference stations, system control center, user’s data center, and real-time datacom network. The SZCORS system provides users the real-time centimeter positioning or post-processing millimeter positioning. This paper makes discussion on the structure of SZCORS system. Some experiments have been made to test the usablity, and then the data has been analyzed.展开更多
Aiming at the problem that traditional optimal operation of hydropower reservoir pays little attention to ecology, an optimal operation model of multi-objective hydropower reservoir with ecology consideration is estab...Aiming at the problem that traditional optimal operation of hydropower reservoir pays little attention to ecology, an optimal operation model of multi-objective hydropower reservoir with ecology consideration is established which combines the ecology and power generation. The model takes the maximum annual power generation benefit, the maximum output of the minimal output stage in the year and the minimum shortage of ecological water demand as objectives, and water quantity balance of reservoir, reservoir storage, discharge flow, output and so on as constraints. Chaotic genetic arithmetic is developed to solve the optimal model. An example is studied, showing that the annual generation of the proposed model is 8 million kW?h less than that model without ecology consideration, which is about 0.28 percent. But the proposed model is in favor of river ecology protection, and can promote the sustainable utilization of water resources. So it is worthy and necessary for the optimal operation of hydropower reservoir with ecology consideration.展开更多
The development of electronic devices that possess the functionality of biological synapses is a crucial step towards neuromorphic computing.In this work,we present a WOx-based memristive device that can emulate volta...The development of electronic devices that possess the functionality of biological synapses is a crucial step towards neuromorphic computing.In this work,we present a WOx-based memristive device that can emulate voltage-dependent synaptic plasticity.By adjusting the amplitude of the applied voltage,we were able to reproduce short-term plasticity(STP)and the transition from STP to long-term potentiation.The stimulation with high intensity induced long-term enhancement of conductance without any decay process,thus representing a permanent memory behavior.Moreover,the image Boolean operations(including intersection,subtraction,and union)were also demonstrated in the memristive synapse array based on the above voltage-dependent plasticity.The experimental achievements of this study provide a new insight into the successful mimicry of essential characteristics of synaptic behaviors.展开更多
Under-ice ambient noise in the Arctic Ocean is studied using the data recorded by autonomous hydrophones at the long-term ice station during the 9th Chinese National Arctic Research Expedition.Time-frequency analysis ...Under-ice ambient noise in the Arctic Ocean is studied using the data recorded by autonomous hydrophones at the long-term ice station during the 9th Chinese National Arctic Research Expedition.Time-frequency analysis of two 7-s-long ice-induced noise samples shows that both ice collision and ice breaking noise have many outliers in the time-domain(impulsive characteristic)and abundant frequency components in the frequency-domain.Ice collision noise lasts for several seconds while the duration of ice breaking noise is much shorter(i.e.,less than tens of milliseconds).Gaussian distribution and symmetric alpha stable(sαs)distribution are used in this paper to fit the impulsive under-ice noise.The sαs distribution can achieve better performance as it can track the heavy tails of impulsive noise while Gaussian distribution fails.This paper also analyzes the meteorological variables during the under-ice noise observation experiment and deduces that the impulsive ambient noise was caused by the combined force of high wind speed and increasing atmosphere temperature on the ice canopy.The Pearson correlation coefficients between long-term power spectral density variations of under-ice ambient noise and meteorological variables are also studied in this paper.展开更多
基金King Abdulaziz City for Science and Technology (KACST) for the fellowshipfunding from the European Union’s Horizon 2020 research and innovation program GRAPHENE Flagship Core 3 under agreement No.: 881603+2 种基金funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement No. 945363funding from the Shanghai Pujiang Program (22PJ1401200)the National Natural Science Foundation of China (No. 52302229)
文摘Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and the charge-carrier transporting layers plays a crucial role in undermining the stability of PSCs.In this work,we propose a strategy to stabilize high-performance PSCs with PCE over 23%by introducing a cesium-doped graphene oxide(GO-Cs)as an interlayer between the perovskite and hole-transporting material.The GO-Cs treated PSCs exhibit excellent operational stability with a projected T80(the time where the device PCE reduces to 80%of its initial value)of 2143 h of operation at the maximum powering point under one sun illumination.
基金support from the National Science and Technology Council of Taiwan(Contract Nos.112-2221-E-011-115 and 111-2622-E-011019)the support from Intelligent Manufacturing Innovation Center(IMIC),National Taiwan University of Science and Technology(NTUST),Taipei 10607,Taiwan,which is a Featured Areas Research Center in Higher Education Sprout Project of Ministry of Education(MOE),Taiwan(since 2023)was appreciated.
文摘In this study,we introduce a novel multi-objective optimization model tailored for modern manufacturing,aiming to mitigate the cost impacts of operational disruptions through optimized corrective maintenance.Central to our approach is the strategic placement of maintenance stations and the efficient allocation of personnel,addressing a crucial gap in the integration of maintenance personnel dispatching and station selection.Our model uniquely combines the spatial distribution of machinery with the expertise of operators to achieve a harmonious balance between maintenance efficiency and cost-effectiveness.The core of our methodology is the NSGA Ⅲ+Dispatch,an advanced adaptation of the Non-Dominated Sorting Genetic Algorithm Ⅲ(NSGA-Ⅲ),meticulously designed for the selection of maintenance stations and effective operator dispatching.This method integrates a comprehensive coding process,crossover operator,and mutation operator to efficiently manage multiple objectives.Rigorous empirical testing,including a detailed analysis from a taiwan region electronic equipment manufacturer,validated the effectiveness of our approach across various scenarios of machine failure frequencies and operator configurations.The findings reveal that the proposed model significantly outperforms current practices by reducing response times by up to 23%in low-frequency and 28.23%in high-frequency machine failure scenarios,leading to notable improvements in efficiency and cost reduction.Additionally,it demonstrates significant improvements in oper-ational efficiency,particularly in selective high-frequency failure contexts,while ensuring substantial manpower cost savings without compromising on operational effectiveness.This research significantly advances maintenance strategies in production environments,providing the manufacturing industry with practical,optimized solutions for diverse machine malfunction situations.Furthermore,the methodologies and principles developed in this study have potential applications in various other sectors,including healthcare,transportation,and energy,where maintenance efficiency and resource optimization are equally critical.
基金financial supports for this research project by the National Natural Science Foundation of China(Nos.41602308,41967037)supported by Zhejiang Provincial Natural Science Foundation of China under Grant No.LY20E080005+1 种基金funded by National Key Research and Development Projects of China(No.2019YFC507502)Guangxi Science and Technology Plan Project(No.RZ2100000161).
文摘During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation.
文摘In the process of designing a municipal rainwater and sewage pumping station,it is necessary to accurately grasp the design points,reasonably determine the scale of the rainwater and sewage pumping station,scientifically select the location and layout,and select materials reasonably.After completing the process design of the municipal rainwater and sewage pumping station and putting it into operation,in order to ensure the normal and stable operation of the pumping station,it is necessary to focus on strengthening the operation and management of diving equipment,cleaning equipment,and electromechanical equipment.The author analyzes the key points and specific design path of the process design of municipal rainwater and sewage pumping stations,and puts forward effective strategies for operation management,hoping to contribute to the scientific design and stable operation of municipal rainwater and sewage pumping stations.
文摘Through investigation and analysis on typical system of pumped-storage stations built in China, this paper approaches the investment andfinancing policies, electricity pricing policies and management modes for suchstations. In order to find out the actual operation situations, eight pumped-storage stations in five provinces (municipality) were investigated, and analysesand calculations were carried out on their investments, benefits, capabilities ofloan-repaying etc. During the investigation and study, the types and the installedcapacities of the stations were paid close attention to, so they were made morerepresentative to reflect the present situation of pumped-storage stations inrespect of construction and operation.
基金The National Key Research and Development Program of China under contract No.2022YFC3104200the Key R&D Program of Shandong Province,China under contract No.2023ZLYS01+3 种基金the Consulting and Research Project of the Chinese Academy of Engineering under contract Nos 2022-XY-21,2022-DFZD-35,2023-XBZD-09 and 2021-XBZD-13the Major Innovation Special Project of Qilu University of Technology(Shandong Academy of Sciences),Science Education Industry Integration Pilot Project under contract No.2023HYZX01Special Funds for“Mount Taishan Scholars”Construction Projectthe Special Funds of Laoshan Laboratory.
文摘In China,operational in-situ marine monitoring is the primary means of directly obtaining hydrological,meteorological,and oceanographic environmental parameters across sea areas,and it is essential for applications such as forecast of marine environment,prevention and mitigation of disaster,exploitation of marine resources,marine environmental protection,and management of transportation safety.In this paper,we summarise the composition,development courses,and present operational status of three systems of operational in-situ marine monitoring,namely coastal marine automated network station,ocean data buoy and voluntary observing ship measuring and reporting system.Additionally,we discuss the technical development in these in-situ systems and achievements in the key generic technologies along with future development trends.
基金supported by Author Special Foundation of National Excellent Doctoral Dissertation of China (Grant No. 2007B41)Jiangsu Provincial Foundation of "333 Talents Engineering" of ChinaJiangsu Provincial Academic Header Foundation of Qinglan Engineering of China
文摘Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjustable blade, mathematical models of pumping station optimal operation are established and solved with genetic algorithm. For different total pumping discharge and total pumping volume of water per day, in order to minimize pumping station operation cost, the number and operation duties of running pump units are respectively determined at different periods of time in a day. The results indicate that the saving of electrical cost is significantly effected by the schemes of adjusting blade angles and time-varying electrical price when pumping certain water volume of water per day, and compared with conventional operation schemes （namely, the schemes of pumping station operation at design blade angles based on certain pumping discharge）, the electrical cost is saved by 4.73%-31.27%. Also, compared with the electrical cost of conventional operation schemes, the electrical cost is saved by 2.03%-5.79% by the schemes of adjusting blade angles when pumping certain discharge.
基金funded by the Project “Resource Characteristics of Main Watersheds and Key Issues in Development and Utilization of Hydroelectricity in South America and Africa”the National Science Foundation of China (U1766201)
文摘The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode of the two can better meet the needs of the electric power system. This article first presents an analysis of the necessity and superiority of such mode, then explains its meaning and analyzes the working routes. Finally, it proposes the business modes as follows: low price pumping water electricity plus nuclear power in the near term;nuclear power shifted to pumped storage power participating in market competition in the middle term;and, in the long term, nuclear power shifted to pumped storage power as primary and serving as an electric power system when needed.
基金supported by the National Natural Science Foundation of China (Grant No. 40971300)the Fundamental Research Funds for the Central Universities (Grant No.10QX43)
文摘Toward solving the actual operation problems of cascade hydropower stations under hydrologic uncertainty, this paper presents the process of extraction of statistical characteristics from long-term optimal cascade operation, and proposes a monthly operation function algorithm for the actual operation of cascade hydropower stations through the identification, processing, and screening of available information during long-term optimal operation. Applying the operation function to the cascade hydropower stations on the Jinshajiang-Yangtze River system, the modeled long-term electric generation is shown to have high precision and provide benefits. Through comparison with optimal operation, the simulation results show that the operation function proposed retains the characteristics of optimal operation. Also, the inadequacies and attribution of the algorithm are discussed based on case study, providing decision support and reference information for research on large-scale cascade operation work.
文摘[Objective] The aim was to study the development and application of operation in comprehensive platform of professional meteorological station.[Method] Taking the operation platform of professional meteorological station in Yantai City as an example,and by dint of VB language and Mysql database technology,the ideas of comprehensive platform development of operation in professional meteorological station,main contents of the platform and its main functions were introduced.[Result] The platform mainly used VB language and Mysql database technology.Gathering together the forecast making,forecast inventory and check,surveillance of data uploading and machine operation and records of shifts,the interface was simple,visual and easy to handle.It reduced reporters’ workload,improved their work efficiency and was the favorite of majority reporters.[Conclusion] The study provided reference for the improvement of work efficiency of each professional meteorological station.
文摘Traditional optimal operation of hydropower station usually has two problems. One is that the optimal algorithm hasn’t high efficiency, and the other is that the optimal operation model pays little attention to ecology. And with the development of electric power market, the generated benefit is concerned instead of generated energy. Based on the analysis of time-varying electricity price policy, an optimal operation model of hydropower station reservoir with ecology consideration is established. The model takes the maximum annual power generation benefit, the maximum output of the minimal output stage in the year and the minimum shortage of eco-environment demand as the objectives, and reservoir water quantity balance, reservoir storage capacity, reservoir discharge flow and hydropower station output and nonnegative variable as the constraints. To solve the optimal model, a chaotic optimization genetic algorithm which combines the ergodicity of chaos and the inversion property of genetic algorithm is exploited. An example is given, which shows that the proposed model and algorithm are scientific and feasible to deal with the optimal operation of hydropower station.
文摘On March 31, in accordance with the typical design requirements of the State Grid, the f irst large electric vehicle (EV) charging station, built by the North China Grid,
基金supported by the National Natural Science Foundation of China under Grant No.51007047
文摘An operation strategy of the electric vehicle （EV） battery charging and swapping station is proposed in the paper. The strategy is established based on comprehensively consideration of the EV charging behaviors and the possible mutual actions between battery charging and swapping. Three energy management strategies can be used in the station： charging period shifting, energy exchange between EVs, and energy supporting from surplus swapping batteries. Then an optimization model which minimizes the total energy management costs of the station is built. The Monte Carlo simulation is applied to analyze the characteristics of the EV battery charging load, and a heuristic algorithm is used to solve the strategy providing the relevant information of EVs and the battery charging and swapping station. The operation strategy can efficiently reduce battery charging during the high electricity price periods and make more reasonable use of the resources. Simulations prove the feasibility and rationality of the strategy.
基金Supported by the National High Technology Research and Development Programme of China(No.2011AA05A108)the National NaturalScience Foundation of China(No.71041025)
文摘In the paper,an operational program of electric bus charging station is proposed,which is special for "The Construction Project for Expo 2010 Temporary Electric Bus Charging Station".Based on the quick-change mode,a vehicle operating schedule model has been established to meet the capacity of transport.Then,according to the quantity of passengers and utilization of batteries,a calculative method of parameters,such as the number of spare batteries and bus departure rules,has been provided.Furthermore,optimal simulation software designed for operating process of the charging station has been identified incorporating actual running data from electric buses and monitoring system of the charging station,and the rationality of the design is verified in the preliminary commissioning and the official operation.
文摘The paper outlines the Yangtze Three Gorges water conservancy complex. It describes the power transmission and distribution equipment in the Three Gorges LeftBank Hydropower Station, especially large high-voltage distribution devices. It elaborates the measures for suppressing GIS over-voltage and the tests on VFTO, besides technical measures to ensure safety and stability of power system in the station. It also makes some analyses and summaries about the problems encountered in operation of the equipment.
文摘Real-time kinematic GPS precise positioning has been playing an increasing role in both surveying and navigation. Based on the city’s fibre LAN network, Shenzhen Continuous Operating Reference Stations (SZCORS) system has been established and consists of GPS reference stations, system control center, user’s data center, and real-time datacom network. The SZCORS system provides users the real-time centimeter positioning or post-processing millimeter positioning. This paper makes discussion on the structure of SZCORS system. Some experiments have been made to test the usablity, and then the data has been analyzed.
文摘Aiming at the problem that traditional optimal operation of hydropower reservoir pays little attention to ecology, an optimal operation model of multi-objective hydropower reservoir with ecology consideration is established which combines the ecology and power generation. The model takes the maximum annual power generation benefit, the maximum output of the minimal output stage in the year and the minimum shortage of ecological water demand as objectives, and water quantity balance of reservoir, reservoir storage, discharge flow, output and so on as constraints. Chaotic genetic arithmetic is developed to solve the optimal model. An example is studied, showing that the annual generation of the proposed model is 8 million kW?h less than that model without ecology consideration, which is about 0.28 percent. But the proposed model is in favor of river ecology protection, and can promote the sustainable utilization of water resources. So it is worthy and necessary for the optimal operation of hydropower reservoir with ecology consideration.
基金the fund from Ministry of Science and Technology of China(Nos.2018YFE0118300 and 2019YFB2205100)the NSFC Program(Nos.11974072,51701037,51732003,51872043,51902048,61774031,61574031 and U19A2091)+4 种基金the“111”Project(No.B13013)the fund from Ministry of Education of China(No.6141A02033414)The fund from China Postdoctoral Science Foundation(No.2019M661185)The Fundamental Research Funds for the Central Universities(No.2412019QD015)the Fund from Jilin Province(JJKH20201163KJ).
文摘The development of electronic devices that possess the functionality of biological synapses is a crucial step towards neuromorphic computing.In this work,we present a WOx-based memristive device that can emulate voltage-dependent synaptic plasticity.By adjusting the amplitude of the applied voltage,we were able to reproduce short-term plasticity(STP)and the transition from STP to long-term potentiation.The stimulation with high intensity induced long-term enhancement of conductance without any decay process,thus representing a permanent memory behavior.Moreover,the image Boolean operations(including intersection,subtraction,and union)were also demonstrated in the memristive synapse array based on the above voltage-dependent plasticity.The experimental achievements of this study provide a new insight into the successful mimicry of essential characteristics of synaptic behaviors.
基金The National Natural Science Foundation of China under contract Nos 61631008,61901136 and 51779061the National Key Research and Development Program of China under contract No.2018YFC1405904+2 种基金the Fok Ying-Tong Education Foundation under contract No.151007the Opening Funding of Science and Technology on Sonar Laboratory under contract No.6142109KF201802the Innovation Special Zone of National Defense Science and Technology.
文摘Under-ice ambient noise in the Arctic Ocean is studied using the data recorded by autonomous hydrophones at the long-term ice station during the 9th Chinese National Arctic Research Expedition.Time-frequency analysis of two 7-s-long ice-induced noise samples shows that both ice collision and ice breaking noise have many outliers in the time-domain(impulsive characteristic)and abundant frequency components in the frequency-domain.Ice collision noise lasts for several seconds while the duration of ice breaking noise is much shorter(i.e.,less than tens of milliseconds).Gaussian distribution and symmetric alpha stable(sαs)distribution are used in this paper to fit the impulsive under-ice noise.The sαs distribution can achieve better performance as it can track the heavy tails of impulsive noise while Gaussian distribution fails.This paper also analyzes the meteorological variables during the under-ice noise observation experiment and deduces that the impulsive ambient noise was caused by the combined force of high wind speed and increasing atmosphere temperature on the ice canopy.The Pearson correlation coefficients between long-term power spectral density variations of under-ice ambient noise and meteorological variables are also studied in this paper.
