To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insul...To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated experimentally.It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation modes.On this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms.Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes.展开更多
As the Chinese government proposes ambitious plans to promote low-carbon transition,energy storage will play a pivotal role in China’s future power system.However,due to the lack of a mature electricity market enviro...As the Chinese government proposes ambitious plans to promote low-carbon transition,energy storage will play a pivotal role in China’s future power system.However,due to the lack of a mature electricity market environment and corresponding mechanisms,current energy storage in China faces problems such as unclear operational models,insufficient cost recovery mechanisms,and a single investment entity,making it difficult to support the rapid development of the energy storage industry.In contrast,European and American countries have already embarked on certain practices in energy storage operation models.Through exploration of key issues such as investment entities,market participation forms,and cost recovery channels in both front and back markets,a wealth of mature experiences has been accumulated.Therefore,this paper first summarizes the existing practices of energy storage operation models in North America,Europe,and Australia’s electricity markets separately from front and back markets,finding that perfect market mechanisms and reasonable subsidy policies are among the main drivers for promoting the rapid development of energy storage markets.Subsequently,combined with the actual development of China’s electricity market,it explores three key issues affecting the construction of costsharing mechanisms for energy storage under market conditions:Market participation forms,investment and operation modes,and cost recovery mechanisms.Finally,in line with the development expectations of China’s future electricitymarket,suggestions are proposed fromfour aspects:Market environment construction,electricity price formation mechanism,cost sharing path,and policy subsidy mechanism,to promote the healthy and rapid development of China’s energy storage industry.展开更多
This paper presents an improved hybrid algorithm and a multi-objective model to tackle the scheduling problem of multiple Automated Guided Vehicles(AGVs)under the composite operation mode.The multi-objective model aim...This paper presents an improved hybrid algorithm and a multi-objective model to tackle the scheduling problem of multiple Automated Guided Vehicles(AGVs)under the composite operation mode.The multi-objective model aims to minimize the maximum completion time,the total distance covered by AGVs,and the distance traveled while empty-loaded.The improved hybrid algorithm combines the improved genetic algorithm(GA)and the simulated annealing algorithm(SA)to strengthen the local search ability of the algorithm and improve the stability of the calculation results.Based on the characteristics of the composite operation mode,the authors introduce the combined coding and parallel decoding mode and calculate the fitness function with the grey entropy parallel analysis method to solve the multi-objective problem.The grey entropy parallel analysis method is a combination of the grey correlation analysis method and the entropy weighting method to solve multi-objective solving problems.A task advance evaluation strategy is proposed in the process of crossover and mutation operator to guide the direction of crossover and mutation.The computational experiments results show that the improved hybrid algorithm is better than the GA and the genetic algorithm with task advance evaluation strategy(AEGA)in terms of convergence speed and solution results,and the effectiveness of the multi-objective solution is proved.All three objectives are optimized and the proposed algorithm has an optimization of 7.6%respectively compared with the GA and 3.4%compared with the AEGA in terms of the objective of maximum completion time.展开更多
With the gradually popularization of replacing coal tobacco leaf flue-curing technology with biomass fuel, the operation of raw materials collection and transportation links faces many problems. In this paper, the exi...With the gradually popularization of replacing coal tobacco leaf flue-curing technology with biomass fuel, the operation of raw materials collection and transportation links faces many problems. In this paper, the existing problems in view of biomass fuel operation dominated by tobacco straw in current tobacco leaf flue-curing were analyzed, and the 3 kinds of fuel operation modes ("contracting processing mode, displacement mode and commercialization mode") were put forward, each of which was also briefly analyzed, with the aim to expand the way of thinking about biomass raw materials processing by cooperative organization.展开更多
The discharge operation regime of pulse modulated atmospheric radio frequency (RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequenc...The discharge operation regime of pulse modulated atmospheric radio frequency (RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequency discharge burst in terms of breakdown voltage, alpha(s)- gamma(γ) mode transition voltage and current are demonstrated by the discharge current voltage characteristics. The minimum breakdown voltage of RF discharge burst was obtained at the duty cycle of 20% and frequency of 400 kHz, respectively. The α-γ mode transition of RF discharge burst occurs at higher voltage and current by reducing the duty cycle and elevating the modulation frequency before the RF discharge burst evolving into the ignition phase, in which the RF discharge burst can operate stably in the γ mode. It proposes that the intensity and stability of RF discharge burst can be improved by manipulating the duty cycle and modulation frequency in pulse modulated atmospheric RF glow discharge.展开更多
Virtual supply chain, as a modern collaborative mode of enterprises, is important to decrease the cost and improve the efficiency and the quality of supply chains, and to satisfy customers. Based on the analysis of th...Virtual supply chain, as a modern collaborative mode of enterprises, is important to decrease the cost and improve the efficiency and the quality of supply chains, and to satisfy customers. Based on the analysis of the conception and characteristics of the virtual supply chain, the architecture of virtual supply chain is built, and corresponding objects, tasks, information and technologies are described. Three operation modes-Order-driven, manufacturer-centered, and retailer-centered are researched. As a case, virtual supply chain is applied in the electronic commerce and networked customization system of ceramic products.展开更多
In order to study the current situation and operation mode of second-hand clothing brand in Europe,this paper makes a field investigation on the second-hand clothing shops in European countries.Through classification ...In order to study the current situation and operation mode of second-hand clothing brand in Europe,this paper makes a field investigation on the second-hand clothing shops in European countries.Through classification of the inspected shops,five representative brands with certain popularity and influence and different operation modes in Europe are selected out from high-grade antique boutiques,non-profit charity organizations,professional retailers and middle-grade consignment shops in the second-hand clothing market.This paper analyzes and discusses the development history of stores,the source of goods,the form of stores,and the operation mode,so as to provide a reference for the development and standardization of the second-hand clothing market in China.展开更多
Teleoperation system plays an important role in executing task under hazard environment. As the computer networks such as the Internet are being used as the communication channel of teleoperation system, varying time ...Teleoperation system plays an important role in executing task under hazard environment. As the computer networks such as the Internet are being used as the communication channel of teleoperation system, varying time delay causes the overall system unstable and reduces the performance of transparency. This paper proposed twelve operation modes with different control schemes for teleoperation on the Internet with time delay. And an optimal operation mode with control scheme was specified for teleoperation with time delay, based on the tradeoff between passivity and transparency properties. It experimentally confirmed the validity of the proposed optimal mode and control scheme by using a simple one DOF master-slave manipulator system.展开更多
The research background is based on great consumption of urban rail transit energy, through summarizing the research of scholars at home and abroad, the comprehensive research including train operation pattern, the tr...The research background is based on great consumption of urban rail transit energy, through summarizing the research of scholars at home and abroad, the comprehensive research including train operation pattern, the train traction characteristics and optimization design of integrated research has carried out in this paper, by using OPENTRACK software simulation to verify the optimization results according to different line features finally. The aim of this paper is to explore ways and methods of traction strategy optimization under the condition of trains timing energy saving. The main research contents of this paper are based on the research status at home and abroad, first of all, the different operating modes of the train running on the line are analysed, including the time saving mode, the energy saving mode and timing energy saving mode, and quantitative analysed the influence of different operation modes on vehicle energy consumption. The influence factors and traction calculation method of energy consumption of train running are studied. Firstly, the factors that affect the energy consumption of the train are analysed, including the basic facilities and transport organization mode. On the basis of this, the train load and running status of the train are analysed, and the model of the train movement and energy consumption are calculated. The OPENTRACK software is used to establish the actual circuit model, and the simulation is verified. The results show that the reasonable operation mode of the train operation mode can greatly reduce the energy consumption.展开更多
The integrated operation mode of green logistics is a new enterprise's logistics operation and management mode concerning, environment issues based on the traditional integrated mode. Through comparative study on the...The integrated operation mode of green logistics is a new enterprise's logistics operation and management mode concerning, environment issues based on the traditional integrated mode. Through comparative study on the integrated operation mode of logistics based on self.operation, the operation mode of an integrated logistics of enterprises based on TPL the green-supply chain management, and the operation mode of eco-iadustrial park (EIP), a relatively complete objective system structure is put forward for the integrated operation mode of green logistics of enterprises. Furthermore, the correspondent practical mode is also set up to help enterprises, especially for the manufacturing companies, not only improve the environment effectively, but support the technological framework for the enterprise's economic performance and social benefits in order to realize economic, social and environmental benefits are concerned.展开更多
Light-framed timber structure(LTS)buildings have been highly valued in recent years due to their low-carbon characteristics.However,the applicability of the building envelope is closely related to indoor and outdoor c...Light-framed timber structure(LTS)buildings have been highly valued in recent years due to their low-carbon characteristics.However,the applicability of the building envelope is closely related to indoor and outdoor conditions.The hot summer and cold winter(HSCW)climate zone in China has high humidity and great temperature variation throughout the year,resulting in distinct outdoor environments in different seasons.The indoor environment is greatly affected by energy-consumption patterns and window-opening habits,which largely depend upon the regulation operations of occupants.All these interrelated factors lead to extremely complex boundary conditions on each side of the building envelope.Whether the structures of LTS buildings are applicable in this climate zone,therefore,needs to be carefully considered.In this study,two LTS buildings with different envelopes were established in Haining,China,situated in the HSCW climate zone,and selected as the study objects.Different operation modes were adopted to create a variety of indoor environments.Under each condition,the processes of heat and moisture transfer within the building envelopes and the indoor environment were monitored and compared.The comparison indicated that the building envelope with high moisture storage and insulation ability maintained a relatively stable indoor environment,especially when the environment changed abruptly.Conversely,if the outdoor environment was equable(e.g.,relative humidity within the range of 30%–60%)or intermittent energy consumption modes were adopted,the building envelope with a low thermal inertia index and weak moisture-buffering ability performed better because it enabled a faster response of the indoor environment to air conditioning.Moreover,a high risk of moisture accumulation between the thermal insulation layer and other materials with a large water vapour transfer resistance factor was also identified,suggesting a higher requirement for the vapour insulation of the envelopes of LTS buildings.展开更多
Utilizing the spatiotemporal features contained in extensive trajectory data for identifying operation modes of agricultural machinery is an important basis task for subsequent agricultural machinery trajectory resear...Utilizing the spatiotemporal features contained in extensive trajectory data for identifying operation modes of agricultural machinery is an important basis task for subsequent agricultural machinery trajectory research.In the present study,to effectively identify agricultural machinery operation mode,a feature deformation network with multi-range feature enhancement was proposed.First,a multi-range feature enhancement module was developed to fully explore the feature distribution of agricultural machinery trajectory data.Second,to further enrich the representation of trajectories,a feature deformation module was proposed that can map trajectory points to high-dimensional space to form feature maps.Then,EfficientNet-B0 was used to extract features of different scales and depths from the feature map,select features highly relevant to the results,and finally accurately predict the mode of each trajectory point.To validate the effectiveness of the proposed method,experiments were conducted to compare the results with those of other methods on a dataset of real agricultural trajectories.On the corn and wheat harvester trajectory datasets,the model achieved accuracies of 96.88%and 96.68%,as well as F1 scores of 93.54%and 94.19%,exhibiting improvements of 8.35%and 9.08%in accuracy and 20.99%and 20.04%in F1 score compared with the current state-of-the-art method.展开更多
A conventional spraying mode and a fully autonomous fruit tree operation mode using a model DJ T30 unmanned aerial vehicle(UAV)were used to control aphids control on elm trees and to clarify the distribution of drople...A conventional spraying mode and a fully autonomous fruit tree operation mode using a model DJ T30 unmanned aerial vehicle(UAV)were used to control aphids control on elm trees and to clarify the distribution of droplets in elm trees sprayed by a UAV.The effects of six aviation spray adjuvants on elm canopy droplet deposition and aphid control were evaluated.ImageJ software was used to analyze and measure the droplet density and deposition of water sensitive paper in two modes;this was done to calculate the droplet uniformity,depositional penetration,and droplet penetration,and to verify the aphid control effect.The results showed that the droplet density increased by 79.7%-100.7% in the upper canopy and 0-394.1%in the lower canopy without adjuvants in the fully autonomous fruit tree operation mode.The upper canopy deposits increased by 65.7%-179.3%,and the lower canopy increased by 0-152.8%.When adjuvants were added,the droplet density in the upper canopy increased by 49.7-56.1%using Jiexiaofeng(JXF),and the lower canopy increased by 138.2%-177.8% using JXF,45.8%-141.3%using Beidatong(BDT),45.5%-92.9% using Gongbei(GB),0-93.5% using Maisi(MS),and 0-95.2%using Manniu(MN).The deposits of the upper canopy increased by 888.1-1154.2% using JXF,0-1298.3% using MN,0-343.9%using BDT,0-422.5% using GB,0-580.3% using MS.The lower canopy increased by 746.4%-1426.0%using JXF,226.2%-231.0% using BDT,435.8%-644.0% using GB,255.0%-322.4%using MS,and 249.3%-360.0%using MN.When JXF was added,the droplet uniformity,droplet penetration and depositional penetration were better than when using other adjuvants.The effects of JXF,BDT and GB in controlling aphids was significantly better than other adjuvants(p<0.05).The following control effects were observed;94.1% with JXF,93.1% with BDT,and 93.3% with GB after 3 d of application,and 97.9% with JXF,95.6% with BDT,and 97.1% with GB after 7 d of application.At the same time,the application of the fully autonomous fruit tree operation mode and JXF can effectively improve the density and deposits,which will produce a superposition optimization effect.Our study focuses on the prevention and control of elm aphid infestations based on the operation mode of a UAV and aviation spray adjuvants,which can provide a baseline for the control of diseases and insect pests using UAVs in agriculture and forestry.展开更多
We present a directed graph-based method for distribution network reconfiguration considering distributed generation. Two reconfiguration situations are considered: operation mode adjustment with the objective of mini...We present a directed graph-based method for distribution network reconfiguration considering distributed generation. Two reconfiguration situations are considered: operation mode adjustment with the objective of minimizing active power loss(situation Ⅰ) and service restoration with the objective of maximizing loads restored(situation Ⅱ). These two situations are modeled as a mixed integer quadratic programming problem and a mixed integer linear programming problem, respectively. The properties of the distribution network with distributed generation considered are reflected as the structure model and the constraints described by directed graph. More specifically, the concepts of "in-degree" and "out-degree"are presented to ensure the radial structure of the distribution network, and the concepts of "virtual node" and"virtual demand" are developed to ensure the connectivity of charged nodes in every independent power supply area.The validity and effectiveness of the proposed method are verified by test results of an IEEE 33-bus system and a 5-feeder system.展开更多
Recent advances in battery energy storage technologies enable increasing number of photovoltaic-battery energy storage systems(PV-BESS)to be deployed and connected with current power grids.The reliable and efficient u...Recent advances in battery energy storage technologies enable increasing number of photovoltaic-battery energy storage systems(PV-BESS)to be deployed and connected with current power grids.The reliable and efficient utilization of BESS imposes an obvious technical challenge which needs to be urgently addressed.In this paper,the optimal operation of PV-BESS based power plant is investigated.The operational scenarios are firstly partitioned using a self-organizing map(SOM)clustering based approach.The revenue optimization model is adopted for the PV-BESS power plants to determine the optimal operational modes under typical conditions for a set of considerations,e.g.power generation revenue,assessing rewards/penalties as well as peak shaving/valley filling revenue.The solution is evaluated through a set of case studies,and the numerical result demonstrates the effectiveness of the suggested solution can optimally operate the BESS with the maximal revenue.展开更多
This paper proposed a discrete operation mode for a punchthrough(PT) phototransistor,which is suitable for low power application,since the bias current is only necessary during the read-out phase.Moreover,simulation...This paper proposed a discrete operation mode for a punchthrough(PT) phototransistor,which is suitable for low power application,since the bias current is only necessary during the read-out phase.Moreover,simulation results show that with the new operation mode,the photocurrent is much larger than that of continuous operation mode.An ultra-high responsivity of 2×10~7A/W at 10^(-9) W/cm^2 is obtained with a small detector size of 1μm^2.In CMOS image sensor applications,with an integration time of 10 ms,a normalized pixel responsivity of 220 V·m^2/W·s·μm^2 is obtained without any auxiliary amplifier.展开更多
A MHD generator with different arrangements of electromagnetic fields will lead the generator working in three modes.A quasi-one-dimensional approximation is used for the model of the MHD generator to analyze the inne...A MHD generator with different arrangements of electromagnetic fields will lead the generator working in three modes.A quasi-one-dimensional approximation is used for the model of the MHD generator to analyze the inner mechanism of operation modes.For the MHD generator with a uniform constant magnetic field,a specific critical electric field E_(cr) is required to decelerate a supersonic entrance flow into a subsonic exit flow.Otherwise,the generator works in a steady mode with a larger electric field than E_(cr) in which a steady supersonic flow is provided at the exit,or the generator works in a choked mode with a smaller electric field than E_(cr) in which the supersonic entrance flow is choked in the channel.The detailed flow field characteristics in different operation modes are discussed,demonstrating the relationship of operation modes with electromagnetic fields.展开更多
This article presents the simulation results and analysis related to the response of the generators within a microgrid towards an accidental overload condition that will require some load shedding action. A microgrid ...This article presents the simulation results and analysis related to the response of the generators within a microgrid towards an accidental overload condition that will require some load shedding action. A microgrid overload can occur due to various reasons ranging from poor load schedule, inadequate switching of circuits within the microgrid, outage of one or more generators inside the microgrid, illegal load connections by some low voltage consumers, etc. It was observed that among the main factors that determine the survival of the microgrid during its transition from the grid connected mode to the islanded mode of operation are the size and type of the load connected (passive or dynamic load) as well as the length of time during which the unexpected load is connected. Models of a speed and voltage regulators of a diesel generator, and important for coping with the overload conditions are provided in the paper. The novelty of the work lies in the load shedding simulation and analysis of the specific generators studied herein, regarding that in many countries the microgrid technology is seen as an important alternative towards the ever increasing load demand and also to assist the system during periods of blackout.展开更多
The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational m...The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational mode identification method,which is based on the sliding time window method and the eigensystem realization algorithm(ERA),is investigated to improve the identification accuracy and stability.Firstly,the theory of the ERA method is introduced.Secondly,the strategy for decomposition and implementation is put forward,including the sliding time window method and the filtration method of modes.At last,an example is studied,where the model of a cantilever beam is built and the white noise exciting is input.Results show that the operational mode identification method can realize the modes,and has high robustness to the signal to noise ratio and signal size.展开更多
IPTV is a promising broadband video service to which telecom operators are attaching great importance. However,there are many challenges especially to confirm operations modes. Under the circumstances of industry regu...IPTV is a promising broadband video service to which telecom operators are attaching great importance. However,there are many challenges especially to confirm operations modes. Under the circumstances of industry regulation in China,the telecom operators may adopt a standard IPTV mode,IP+TV mode or pure IP mode according to specific requirements when deploying IPTV services that are personalized and interactive. The development of IPTV faces numerous difficulties such as unclear supervision policy,industry barrier difficult to be removed,vague profit models,and imperfect technology specifications. However,the general development tendency decides a bright future of IPTV.展开更多
基金supported in part by the Huxiang Youth Talent Support Program(No.2020RC3030)in part by the Foundation of State Key Laboratory of Pulsed Power Laser Technology(Nos.SKL2021ZR02 and SKL2021KF05)。
文摘To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated experimentally.It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation modes.On this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms.Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes.
基金supported financially by State Grid Henan Electric Power Company Technology Project“Research on System Cost Impact Assessment and Sharing Mechanism under the Rapid Development of Distributed Photovoltaics”(Grant Number:5217L0220021).
文摘As the Chinese government proposes ambitious plans to promote low-carbon transition,energy storage will play a pivotal role in China’s future power system.However,due to the lack of a mature electricity market environment and corresponding mechanisms,current energy storage in China faces problems such as unclear operational models,insufficient cost recovery mechanisms,and a single investment entity,making it difficult to support the rapid development of the energy storage industry.In contrast,European and American countries have already embarked on certain practices in energy storage operation models.Through exploration of key issues such as investment entities,market participation forms,and cost recovery channels in both front and back markets,a wealth of mature experiences has been accumulated.Therefore,this paper first summarizes the existing practices of energy storage operation models in North America,Europe,and Australia’s electricity markets separately from front and back markets,finding that perfect market mechanisms and reasonable subsidy policies are among the main drivers for promoting the rapid development of energy storage markets.Subsequently,combined with the actual development of China’s electricity market,it explores three key issues affecting the construction of costsharing mechanisms for energy storage under market conditions:Market participation forms,investment and operation modes,and cost recovery mechanisms.Finally,in line with the development expectations of China’s future electricitymarket,suggestions are proposed fromfour aspects:Market environment construction,electricity price formation mechanism,cost sharing path,and policy subsidy mechanism,to promote the healthy and rapid development of China’s energy storage industry.
基金the Shandong Province Key Research and Development Program under Grant No.2021SFGC0601.
文摘This paper presents an improved hybrid algorithm and a multi-objective model to tackle the scheduling problem of multiple Automated Guided Vehicles(AGVs)under the composite operation mode.The multi-objective model aims to minimize the maximum completion time,the total distance covered by AGVs,and the distance traveled while empty-loaded.The improved hybrid algorithm combines the improved genetic algorithm(GA)and the simulated annealing algorithm(SA)to strengthen the local search ability of the algorithm and improve the stability of the calculation results.Based on the characteristics of the composite operation mode,the authors introduce the combined coding and parallel decoding mode and calculate the fitness function with the grey entropy parallel analysis method to solve the multi-objective problem.The grey entropy parallel analysis method is a combination of the grey correlation analysis method and the entropy weighting method to solve multi-objective solving problems.A task advance evaluation strategy is proposed in the process of crossover and mutation operator to guide the direction of crossover and mutation.The computational experiments results show that the improved hybrid algorithm is better than the GA and the genetic algorithm with task advance evaluation strategy(AEGA)in terms of convergence speed and solution results,and the effectiveness of the multi-objective solution is proved.All three objectives are optimized and the proposed algorithm has an optimization of 7.6%respectively compared with the GA and 3.4%compared with the AEGA in terms of the objective of maximum completion time.
基金Supported by the Science and Technology Project of Yunnan Tobacco Co.,Ltd.(2016YN01)~~
文摘With the gradually popularization of replacing coal tobacco leaf flue-curing technology with biomass fuel, the operation of raw materials collection and transportation links faces many problems. In this paper, the existing problems in view of biomass fuel operation dominated by tobacco straw in current tobacco leaf flue-curing were analyzed, and the 3 kinds of fuel operation modes ("contracting processing mode, displacement mode and commercialization mode") were put forward, each of which was also briefly analyzed, with the aim to expand the way of thinking about biomass raw materials processing by cooperative organization.
基金supported by National Natural Science Foundation of China(Nos.11475043 and 11375042)
文摘The discharge operation regime of pulse modulated atmospheric radio frequency (RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequency discharge burst in terms of breakdown voltage, alpha(s)- gamma(γ) mode transition voltage and current are demonstrated by the discharge current voltage characteristics. The minimum breakdown voltage of RF discharge burst was obtained at the duty cycle of 20% and frequency of 400 kHz, respectively. The α-γ mode transition of RF discharge burst occurs at higher voltage and current by reducing the duty cycle and elevating the modulation frequency before the RF discharge burst evolving into the ignition phase, in which the RF discharge burst can operate stably in the γ mode. It proposes that the intensity and stability of RF discharge burst can be improved by manipulating the duty cycle and modulation frequency in pulse modulated atmospheric RF glow discharge.
文摘Virtual supply chain, as a modern collaborative mode of enterprises, is important to decrease the cost and improve the efficiency and the quality of supply chains, and to satisfy customers. Based on the analysis of the conception and characteristics of the virtual supply chain, the architecture of virtual supply chain is built, and corresponding objects, tasks, information and technologies are described. Three operation modes-Order-driven, manufacturer-centered, and retailer-centered are researched. As a case, virtual supply chain is applied in the electronic commerce and networked customization system of ceramic products.
基金the China Scholarship Council(Project No.201806795029)MOE(Ministry of Education in China)Project of Humanities and Social Sciences(Project No.19YJC760096)for supporting the project.
文摘In order to study the current situation and operation mode of second-hand clothing brand in Europe,this paper makes a field investigation on the second-hand clothing shops in European countries.Through classification of the inspected shops,five representative brands with certain popularity and influence and different operation modes in Europe are selected out from high-grade antique boutiques,non-profit charity organizations,professional retailers and middle-grade consignment shops in the second-hand clothing market.This paper analyzes and discusses the development history of stores,the source of goods,the form of stores,and the operation mode,so as to provide a reference for the development and standardization of the second-hand clothing market in China.
基金Foundation for U niversity Key Teacher bythe Ministry of Education and National Natural Science Founda-tion of China ( No.69875 0 0 4) and 863 High-Tech Plan ( No.2 0 0 1AA42 3 2 40 )
文摘Teleoperation system plays an important role in executing task under hazard environment. As the computer networks such as the Internet are being used as the communication channel of teleoperation system, varying time delay causes the overall system unstable and reduces the performance of transparency. This paper proposed twelve operation modes with different control schemes for teleoperation on the Internet with time delay. And an optimal operation mode with control scheme was specified for teleoperation with time delay, based on the tradeoff between passivity and transparency properties. It experimentally confirmed the validity of the proposed optimal mode and control scheme by using a simple one DOF master-slave manipulator system.
文摘The research background is based on great consumption of urban rail transit energy, through summarizing the research of scholars at home and abroad, the comprehensive research including train operation pattern, the train traction characteristics and optimization design of integrated research has carried out in this paper, by using OPENTRACK software simulation to verify the optimization results according to different line features finally. The aim of this paper is to explore ways and methods of traction strategy optimization under the condition of trains timing energy saving. The main research contents of this paper are based on the research status at home and abroad, first of all, the different operating modes of the train running on the line are analysed, including the time saving mode, the energy saving mode and timing energy saving mode, and quantitative analysed the influence of different operation modes on vehicle energy consumption. The influence factors and traction calculation method of energy consumption of train running are studied. Firstly, the factors that affect the energy consumption of the train are analysed, including the basic facilities and transport organization mode. On the basis of this, the train load and running status of the train are analysed, and the model of the train movement and energy consumption are calculated. The OPENTRACK software is used to establish the actual circuit model, and the simulation is verified. The results show that the reasonable operation mode of the train operation mode can greatly reduce the energy consumption.
文摘The integrated operation mode of green logistics is a new enterprise's logistics operation and management mode concerning, environment issues based on the traditional integrated mode. Through comparative study on the integrated operation mode of logistics based on self.operation, the operation mode of an integrated logistics of enterprises based on TPL the green-supply chain management, and the operation mode of eco-iadustrial park (EIP), a relatively complete objective system structure is put forward for the integrated operation mode of green logistics of enterprises. Furthermore, the correspondent practical mode is also set up to help enterprises, especially for the manufacturing companies, not only improve the environment effectively, but support the technological framework for the enterprise's economic performance and social benefits in order to realize economic, social and environmental benefits are concerned.
基金supported by the National Natural Science Foundation of China(No.51978623).
文摘Light-framed timber structure(LTS)buildings have been highly valued in recent years due to their low-carbon characteristics.However,the applicability of the building envelope is closely related to indoor and outdoor conditions.The hot summer and cold winter(HSCW)climate zone in China has high humidity and great temperature variation throughout the year,resulting in distinct outdoor environments in different seasons.The indoor environment is greatly affected by energy-consumption patterns and window-opening habits,which largely depend upon the regulation operations of occupants.All these interrelated factors lead to extremely complex boundary conditions on each side of the building envelope.Whether the structures of LTS buildings are applicable in this climate zone,therefore,needs to be carefully considered.In this study,two LTS buildings with different envelopes were established in Haining,China,situated in the HSCW climate zone,and selected as the study objects.Different operation modes were adopted to create a variety of indoor environments.Under each condition,the processes of heat and moisture transfer within the building envelopes and the indoor environment were monitored and compared.The comparison indicated that the building envelope with high moisture storage and insulation ability maintained a relatively stable indoor environment,especially when the environment changed abruptly.Conversely,if the outdoor environment was equable(e.g.,relative humidity within the range of 30%–60%)or intermittent energy consumption modes were adopted,the building envelope with a low thermal inertia index and weak moisture-buffering ability performed better because it enabled a faster response of the indoor environment to air conditioning.Moreover,a high risk of moisture accumulation between the thermal insulation layer and other materials with a large water vapour transfer resistance factor was also identified,suggesting a higher requirement for the vapour insulation of the envelopes of LTS buildings.
基金supported by the National Natural Science Foundation of China(Grant No.32301691)the National Key R&D Program of China and Shandong Province,China(Grant No.2021YFB3901300)the National Precision Agriculture Application Project(Grant/Contract number:JZNYYY001).
文摘Utilizing the spatiotemporal features contained in extensive trajectory data for identifying operation modes of agricultural machinery is an important basis task for subsequent agricultural machinery trajectory research.In the present study,to effectively identify agricultural machinery operation mode,a feature deformation network with multi-range feature enhancement was proposed.First,a multi-range feature enhancement module was developed to fully explore the feature distribution of agricultural machinery trajectory data.Second,to further enrich the representation of trajectories,a feature deformation module was proposed that can map trajectory points to high-dimensional space to form feature maps.Then,EfficientNet-B0 was used to extract features of different scales and depths from the feature map,select features highly relevant to the results,and finally accurately predict the mode of each trajectory point.To validate the effectiveness of the proposed method,experiments were conducted to compare the results with those of other methods on a dataset of real agricultural trajectories.On the corn and wheat harvester trajectory datasets,the model achieved accuracies of 96.88%and 96.68%,as well as F1 scores of 93.54%and 94.19%,exhibiting improvements of 8.35%and 9.08%in accuracy and 20.99%and 20.04%in F1 score compared with the current state-of-the-art method.
基金financially supported by the Xinjiang Production and Construction Corps Science and Technology Breakthrough Plan Project(2019AB023).
文摘A conventional spraying mode and a fully autonomous fruit tree operation mode using a model DJ T30 unmanned aerial vehicle(UAV)were used to control aphids control on elm trees and to clarify the distribution of droplets in elm trees sprayed by a UAV.The effects of six aviation spray adjuvants on elm canopy droplet deposition and aphid control were evaluated.ImageJ software was used to analyze and measure the droplet density and deposition of water sensitive paper in two modes;this was done to calculate the droplet uniformity,depositional penetration,and droplet penetration,and to verify the aphid control effect.The results showed that the droplet density increased by 79.7%-100.7% in the upper canopy and 0-394.1%in the lower canopy without adjuvants in the fully autonomous fruit tree operation mode.The upper canopy deposits increased by 65.7%-179.3%,and the lower canopy increased by 0-152.8%.When adjuvants were added,the droplet density in the upper canopy increased by 49.7-56.1%using Jiexiaofeng(JXF),and the lower canopy increased by 138.2%-177.8% using JXF,45.8%-141.3%using Beidatong(BDT),45.5%-92.9% using Gongbei(GB),0-93.5% using Maisi(MS),and 0-95.2%using Manniu(MN).The deposits of the upper canopy increased by 888.1-1154.2% using JXF,0-1298.3% using MN,0-343.9%using BDT,0-422.5% using GB,0-580.3% using MS.The lower canopy increased by 746.4%-1426.0%using JXF,226.2%-231.0% using BDT,435.8%-644.0% using GB,255.0%-322.4%using MS,and 249.3%-360.0%using MN.When JXF was added,the droplet uniformity,droplet penetration and depositional penetration were better than when using other adjuvants.The effects of JXF,BDT and GB in controlling aphids was significantly better than other adjuvants(p<0.05).The following control effects were observed;94.1% with JXF,93.1% with BDT,and 93.3% with GB after 3 d of application,and 97.9% with JXF,95.6% with BDT,and 97.1% with GB after 7 d of application.At the same time,the application of the fully autonomous fruit tree operation mode and JXF can effectively improve the density and deposits,which will produce a superposition optimization effect.Our study focuses on the prevention and control of elm aphid infestations based on the operation mode of a UAV and aviation spray adjuvants,which can provide a baseline for the control of diseases and insect pests using UAVs in agriculture and forestry.
基金supported by the National Science and Technology Support Program of China (No. 2013BAA01B02)
文摘We present a directed graph-based method for distribution network reconfiguration considering distributed generation. Two reconfiguration situations are considered: operation mode adjustment with the objective of minimizing active power loss(situation Ⅰ) and service restoration with the objective of maximizing loads restored(situation Ⅱ). These two situations are modeled as a mixed integer quadratic programming problem and a mixed integer linear programming problem, respectively. The properties of the distribution network with distributed generation considered are reflected as the structure model and the constraints described by directed graph. More specifically, the concepts of "in-degree" and "out-degree"are presented to ensure the radial structure of the distribution network, and the concepts of "virtual node" and"virtual demand" are developed to ensure the connectivity of charged nodes in every independent power supply area.The validity and effectiveness of the proposed method are verified by test results of an IEEE 33-bus system and a 5-feeder system.
文摘Recent advances in battery energy storage technologies enable increasing number of photovoltaic-battery energy storage systems(PV-BESS)to be deployed and connected with current power grids.The reliable and efficient utilization of BESS imposes an obvious technical challenge which needs to be urgently addressed.In this paper,the optimal operation of PV-BESS based power plant is investigated.The operational scenarios are firstly partitioned using a self-organizing map(SOM)clustering based approach.The revenue optimization model is adopted for the PV-BESS power plants to determine the optimal operational modes under typical conditions for a set of considerations,e.g.power generation revenue,assessing rewards/penalties as well as peak shaving/valley filling revenue.The solution is evaluated through a set of case studies,and the numerical result demonstrates the effectiveness of the suggested solution can optimally operate the BESS with the maximal revenue.
基金Project supported by the National Natural Science Foundation of China(Nos.61076046,61274023)the New Century Excellent Talents Support Program of the Ministry of Educationthe Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory(No.ZHD201204)
文摘This paper proposed a discrete operation mode for a punchthrough(PT) phototransistor,which is suitable for low power application,since the bias current is only necessary during the read-out phase.Moreover,simulation results show that with the new operation mode,the photocurrent is much larger than that of continuous operation mode.An ultra-high responsivity of 2×10~7A/W at 10^(-9) W/cm^2 is obtained with a small detector size of 1μm^2.In CMOS image sensor applications,with an integration time of 10 ms,a normalized pixel responsivity of 220 V·m^2/W·s·μm^2 is obtained without any auxiliary amplifier.
基金supported in part by the National Natural Science Foundation of China under Grant 51006027,Grant 50925625,and Grant 51437002the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology under Grant HIT.NSRIF.2009091the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant 20102302120047
文摘A MHD generator with different arrangements of electromagnetic fields will lead the generator working in three modes.A quasi-one-dimensional approximation is used for the model of the MHD generator to analyze the inner mechanism of operation modes.For the MHD generator with a uniform constant magnetic field,a specific critical electric field E_(cr) is required to decelerate a supersonic entrance flow into a subsonic exit flow.Otherwise,the generator works in a steady mode with a larger electric field than E_(cr) in which a steady supersonic flow is provided at the exit,or the generator works in a choked mode with a smaller electric field than E_(cr) in which the supersonic entrance flow is choked in the channel.The detailed flow field characteristics in different operation modes are discussed,demonstrating the relationship of operation modes with electromagnetic fields.
文摘This article presents the simulation results and analysis related to the response of the generators within a microgrid towards an accidental overload condition that will require some load shedding action. A microgrid overload can occur due to various reasons ranging from poor load schedule, inadequate switching of circuits within the microgrid, outage of one or more generators inside the microgrid, illegal load connections by some low voltage consumers, etc. It was observed that among the main factors that determine the survival of the microgrid during its transition from the grid connected mode to the islanded mode of operation are the size and type of the load connected (passive or dynamic load) as well as the length of time during which the unexpected load is connected. Models of a speed and voltage regulators of a diesel generator, and important for coping with the overload conditions are provided in the paper. The novelty of the work lies in the load shedding simulation and analysis of the specific generators studied herein, regarding that in many countries the microgrid technology is seen as an important alternative towards the ever increasing load demand and also to assist the system during periods of blackout.
基金supported in part by the National Basic Research Program of China (No. JCKY2016203B032)
文摘The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational mode identification method,which is based on the sliding time window method and the eigensystem realization algorithm(ERA),is investigated to improve the identification accuracy and stability.Firstly,the theory of the ERA method is introduced.Secondly,the strategy for decomposition and implementation is put forward,including the sliding time window method and the filtration method of modes.At last,an example is studied,where the model of a cantilever beam is built and the white noise exciting is input.Results show that the operational mode identification method can realize the modes,and has high robustness to the signal to noise ratio and signal size.
文摘IPTV is a promising broadband video service to which telecom operators are attaching great importance. However,there are many challenges especially to confirm operations modes. Under the circumstances of industry regulation in China,the telecom operators may adopt a standard IPTV mode,IP+TV mode or pure IP mode according to specific requirements when deploying IPTV services that are personalized and interactive. The development of IPTV faces numerous difficulties such as unclear supervision policy,industry barrier difficult to be removed,vague profit models,and imperfect technology specifications. However,the general development tendency decides a bright future of IPTV.