A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international l...A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international literature has contributed to the understanding of the essential aspects to be verified regarding the quality of EIS, offering a wide spectrum of good practice examples related to the content of the studies. Even so, there is a need for empirical studies that allow the identification of specific aspects related to the context of application of the EIS, which could lead to the identification of opportunities to improve both the quality of the reports and also the effectiveness of EIA. Therefore, the present paper is focused on the quality review of a number of EIS submitted to the Brazilian Federal Environmental Agency (Ibama) to instruct the assessment of electric power transmission systems. Based on the application of the EIS quality review package as proposed by Lee and Colley (1992), the outcomes reveal opportunities for improving the scope of EIA, analysis of alternatives, prediction of magnitude and the assessment of impact significance. Finally, the development and/or adaptation of a similar tool for the systematic review of the quality of EIA reports is recommended.展开更多
The economics,infrastructure,transportation,and level of living of a country are all influenced by energy.The gap between energy usage and availabil-ity is a global issue.Currently,all countries rely on fossil fuels fo...The economics,infrastructure,transportation,and level of living of a country are all influenced by energy.The gap between energy usage and availabil-ity is a global issue.Currently,all countries rely on fossil fuels for energy genera-tion,and these fossil fuels are not sustainable.The hydrogen proton exchange membrane fuel cell(PEMFC)power system is both clean and efficient.The fuel delivery system and the PEMFC make up the majority of the PEMFC power sys-tem.The lack of an efficient,safe,and cost-effective hydrogen storage system is still a major barrier to its widespread use.Solid hydrogen storage has the large capacity,safety and good reversibility.As a hydrogen source system,the hydro-gen supply characteristics affect the characteristics of the PEMFC at the output.In this paper,a mathematical model of a hydrogen source reactor and PEMFC based on chemical absorption/desorption of solid hydrogen storage is established,and a simulation model of a PEMFC power system coupled with solid hydrogen storage is established using MATLAB/SIMULINK software,and the hydrogen supply of the reactor is analyzed in detail.The influence of prominent factors is evaluated.The research results show that the proposed method improved the system perfor-mance.At the same time,increasing the PEMFC temperature,increasing the area of the proton exchange membrane and the oxygen supply pressure can increase the output power of the power system.展开更多
The on-site inspection of high-power DC chargers results in new DC high-current measurement and DC energy traceability system requirements.This paper studies the traceability technology of electric energy value for au...The on-site inspection of high-power DC chargers results in new DC high-current measurement and DC energy traceability system requirements.This paper studies the traceability technology of electric energy value for automotive high-power DC chargers,including:(1)the traceability method of the built-in DC energy meter and shunt of the charger;(2)precision DC high current and small precision DC voltage output and measurement technology.This paper designs a 0.1 mA∼600 A DC high current measurement system and proposes a 0.005 level DC powermeasurement traceability system.The uncertainty evaluation experiment of theDC powermeasurement calibration system and the high-power DC charger’s on-site calibration experiment results verify the method’s effectiveness and feasibility in this paper.The experimental results show that the combined standard uncertainty of the DC power metering verification system can be 0.0451%.展开更多
The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sou...The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sources.One potential technology,the Microbial Fuel Cell(MFC)based on rice,vegetable,and fruit wastes,can convert chemical energy into electrical energy.This study aims to determine the potency of rice,vegetable,and fruit waste assisted by Cu/Mg electrodes as a generator of electricity.The method used was a laboratory experiment,including the following steps:electrode preparation,waste sample preparation,incubation of the waste samples,construction of a reactor using rice,vegetable,and fruit waste as a source of electricity,and testing.The tests included measuring electrical conductivity,electric current,voltage,current density,and power density.Based on the test results,the maximum current and voltage values for the fruit waste samples were 5.53 V and 11.5 mA,respectively,with a current density of 2.300 mA/cm^(2) and a power density of 12.719 mW/cm^(2).The results indicate the potential for a future development.The next step in development involves determining the optimum conditions for utilizing of rice,vegetable,and fruit waste.The results of the electrical conductivity test on rice,vegetable,and fruit waste samples were 1.51,2.88,and 3.98 mS,respectively,with the highest electrical conductivity value found in the fruit waste sample.展开更多
With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new ...With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new challenges to the operation of the grid.Firstly,A novel bidirectional interaction model is established based on modulation theory with nonlinear loads.Then,the electric energy measuring scheme of EVs for V2G is derived under the conditions of distorted power loads.The scheme is composed of fundamental electric energy,fundamental-distorted electric energy,distorted-fundamental electric energy and distorted electric energy.And the characteristics of each electric energy are analyzed.Finally,the correctness of the model and energy measurement method is verified by three simulation cases:the impact signals,the fluctuating signals,and the harmonic signals.展开更多
The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is o...The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus (BP) by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10 V/nm to 0.83 V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronies, thermoelectric power generation and thermal imaging.展开更多
A novel parallel hybrid electrical urban bus (PHEUB) configuration consisting of an extra one-way clutch and an automatic mechanical transmission (AMT) is taken as the study subject. An energy management strategy ...A novel parallel hybrid electrical urban bus (PHEUB) configuration consisting of an extra one-way clutch and an automatic mechanical transmission (AMT) is taken as the study subject. An energy management strategy combining a logic threshold approach and an instantaneous optimization algorithm is proposed for the investigated PHEUB. The objective of the energy management strategy is to achieve acceptable vehicle performance and drivability requirements while simultaneously maximizing the engine fuel consumption and maintaining the battery state of charge in its operation range at all times. Under the environment of Matlab/Simulink, a computer simulation model for the PHEUB is constructed by using the model building method combining theoretical analysis and bench test data. Simulation and experiment results for China Typical Bus Driving Schedule at Urban District (CTBDS_UD) are obtained, and the results indicate that the proposed control strategy not only controls the hybrid system efficiently but also improves the fuel economy significantly.展开更多
The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR s...The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD (T) method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect.展开更多
This article aims at giving a contribution to the issue of accounting electrical energy sale and purchase agreements in accordance with the faithful representation principle. To this end, it must be ascertained whethe...This article aims at giving a contribution to the issue of accounting electrical energy sale and purchase agreements in accordance with the faithful representation principle. To this end, it must be ascertained whether electrical energy is bought/sold for an industrial use exclusively, so that the relevant transaction will be accounted as a normal purchase/sale, or through the lease of the relevant production plant, which would require the supply contract to be accounted in compliance with International Accounting Standards (IAS) 17 "Leasing". Alternatively, it must also be ascertained whether the relevant party is implementing financial trading strategies, as in such hypothesis, the supply contract is to be accounted as a financial instrument according to International Financial Reporting Standards (IFRS) 9/IAS 39 "Financial Instruments". Finally, the modalities used by a number of companies listed on European regulated markets to account such kind of contracts will be analyzed.展开更多
This article puts forward an automatic recognition algorithm of electric energy meter lead seals: firstly, the image will be histogram equalization, smoothing, binaryzation pretreatment, then according to the image c...This article puts forward an automatic recognition algorithm of electric energy meter lead seals: firstly, the image will be histogram equalization, smoothing, binaryzation pretreatment, then according to the image characteristics of text changes, the system can quickly and accurately segment image from complex background, finally the system extract different dimension and the feature of English and Arabia using digital projection transform coefficient method and to identify the corresponding number by BP neural network, solves the problem of automatic recognition of electric energy meter lead sealing.展开更多
Considering the additional electric energy generated after the full operation of the underground hydropower station, the electric energy accommodation of the Three Gorges Project (TGP) is reviewed. It is .focused on...Considering the additional electric energy generated after the full operation of the underground hydropower station, the electric energy accommodation of the Three Gorges Project (TGP) is reviewed. It is .focused on the additional electricity accommodation, based on the research at the earl), stage. The electric energ), accommodation solutions ate recommended as that. based on the cost-benefit analysis of the power distribution area, the additional electric energy of the Three Gorges should be given ptqority to meet the needs at the supply end of Hubei and Chongqing. The results of this research has a reference value on the implementation of the Three Gorges electric power accommodation, after the further optimization of the transmission curves in both wet and dry seasons.展开更多
Increased pollution levels have caused damage to our planet. Many scientists are now warning on the long term effects. Green houses gases causes more of the sunlight to be trapped within the Earth’s atmosphere and th...Increased pollution levels have caused damage to our planet. Many scientists are now warning on the long term effects. Green houses gases causes more of the sunlight to be trapped within the Earth’s atmosphere and thus causing increased Earth temperature. Individuals, governments, and private entities are now acting on fixing this problem. One of the most promising solutions is installing an array of solar cells in residential areas. Doing so makes sense for areas with abundant sunlight as the dependency on the grid can be minimized and even completely illuminated while providing a feasible economic perspective at the same time. This paper presents the modelling of a residential setup as a complete system along with an electric vehicle. The modelled components include: Photovoltaic Cells, Home Load Usage, Electric Vehicle, High-Voltage battery as an energy storage, Boost, and Inverter. The presented analysis will help engineers and system designers do better cost analysis. The study can also be used as a basis for maximizing the solar energy usage and perform component optimization.展开更多
Aiming at the shortcomings of the existing electric energy metering method,combining with the harmonic responsibility analysis model based on the reference impedance method and the idea of apparent power decomposition...Aiming at the shortcomings of the existing electric energy metering method,combining with the harmonic responsibility analysis model based on the reference impedance method and the idea of apparent power decomposition in IEEE Std 1459-2010 standard,two new metering indicators—billing active power and billing power factor are defined.A new electric energy metering method is proposed and its specific implementation steps are given.The simulation model is built in Matlab/Simulink,and three different examples are set up.Using the simulation data,the various metering indicators need to be examined by the existing electric energy metering method and the new electric energy metering method are calculated.The calculation results show that the new electric energy metering method not only overcomes the shortcomings of the existing electric energy metering method,but also is very easy to be popularized and applied.展开更多
Along with the massive applications of the non-linear loads and the impact loads, many non-stationary stochastic signals such as harmonics, inter-harmonics, impulse signals and so on are introduced into the electric n...Along with the massive applications of the non-linear loads and the impact loads, many non-stationary stochastic signals such as harmonics, inter-harmonics, impulse signals and so on are introduced into the electric network, and these non-stationary stochastic signals have had effects on the accuracy of the measurement of electric energy. The traditional method like Fourier Analysis can he applied efficiently on the stationary stochastic signals, hut it has little effect on non-stationary stochastic signals. In light of this, the form of the signals of the electric network in wavelet domain will he discussed in this paper. A measurement method of active power based on multi-resolution analysis in the stochastic process is presented. This method has a wider application scope compared with the traditional method Fourier analysis, and it is of good referential value and practical value in terms of raising the level of the existing electric energy measurement.展开更多
The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing suppl...The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing supply chain and related activities into a value network (VN). Previous researches on crowd value network concepts focus on the activities of infrastructure and load management and neglect activities that generate collaboration. Collaboration with and within crowds particularly demands a different mindset and management of sharing values, information, benefit, and risks. Furthermore, these concepts must integrate technical, processual, and social aspects. Thus, this article proposes a holistic framework of electricity VN management for crowd energy. It redefines VN activities for infrastructure and load management while appending VN activities for social electricity handling. Additionally, the framework illustrates the interactions among these three elements and concludes with an adaption cycle for the crowd value network.展开更多
Over all fuel condition and the money we spend on the said fuel leads us to think about savings. What can we do? As individuals, we can educate our students and their family members. The easiest way to do that is to ...Over all fuel condition and the money we spend on the said fuel leads us to think about savings. What can we do? As individuals, we can educate our students and their family members. The easiest way to do that is to monitor their weekly spending for them. Together with their family members, the students have to monitor the consumption of electrical energy through three weeks. In the first week, they should spend electricity as they do everyday. During the second week they have the increase of spending of electrical energy. The third week is the saving energy week. They have to make a plan with their family members on how to save energy, for example, turning offthe lights in the empty rooms, turning offthe TV when there is no one watching it, etc.. Every week they have to note the data in kilowatts. When they acquire all the information and transform it into money they can see if it's worth saving electrical energy or not. They will see they don't have to give up the comforts of the modern life. The value of the project is in the fact that many households continue with the electrical energy saving. In fact, the number of the households is increasing.展开更多
<span style="font-family:Verdana;">Today, energy is a vital component in the functioning of a hospital. Hospital technical facilities have several types of technologies, these include appliances for us...<span style="font-family:Verdana;">Today, energy is a vital component in the functioning of a hospital. Hospital technical facilities have several types of technologies, these include appliances for use;examination apparatus. So, for Quality Health Care in a hospital, there is</span><span style="font-family:Verdana;"> a</span><span style="font-family:Verdana;"> need to ensure the proper functioning of hospital equipment. In addition to the required maintenance as specified by the device manufacturer, </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">quality of the electrical energy across the device must be ensured. This article is an analysis of the quality of electric energy at the substation of National Hospital of Niamey. Thereby, the data collection, followed by the data processing and analysis revealed the parameters characterizing the quality of electrical energy across the substation. Our studies have shown that the substation is underutilized as the maximum inrush current is less than half the available current. </span><span style="font-family:Verdana;">The </span><span style="font-family:Verdana;">current </span><span style="font-family:Verdana;">was </span><span style="font-family:Verdana;">consumed by the three phases ha</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> resulted </span><span style="font-family:Verdana;">in</span><span style="font-family:Verdana;"> a strong current unbalance (230</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">A). However, the current unbalance and the voltage amplitude</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> are admissible according</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> base on EN50160 standard. Furthermore, the harmonics voltages present in this medium </span><span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> in the accepted range (1.8%) according to IEEE 519 standard. However, the fundamental frequency does not meet the standard, but the difference obtained has no adverse effect.</span>展开更多
The urgent need for sustainable energy choices, local sustainable value creation, and reduction of import dependencies and non-sustainable resource use in Namibia cannot be over emphasised. This study was conducted wi...The urgent need for sustainable energy choices, local sustainable value creation, and reduction of import dependencies and non-sustainable resource use in Namibia cannot be over emphasised. This study was conducted with the ultimate goal to provide the basis for accurate energy fuel mix and climate change monitoring, and reporting and planning for addressing a global problem at local/domestic level. The energy consumption and production data for the country were used with International Panel on Climate Change (IPCC) and International Energy Agency (IEA) conversions, and carbon footprint calculation tools to determine the GHG emissions and air pollutants per type of energy fuel;and the carbon footprint associated with each energy fuel option for the country. The study showed that: 1) there is no single energy fuel which is not associated with GHG emissions and/or other environmental implications;2) increase in population and energy consumption and production yields increase in GHGs and other major pollutants (SO<sub>x</sub>, NO<sub>x</sub>, Particulate Matter);and 3) the choice of fuel mix determines the success of GHG emissions reduction. A future energy mix dominated by renewable energy technologies;and a balanced view of the actual benefits of the Namibian energy supply choices was also recommended.展开更多
An automatic generation control strategy based on balance of daily total electric energy is put forward. It makes the balance between actual total generated energy controlled by automatic generation system and planned...An automatic generation control strategy based on balance of daily total electric energy is put forward. It makes the balance between actual total generated energy controlled by automatic generation system and planned total energy on base of area control error, and makes the actual 24-hour active power load curve to approach the planned load curve. The generated energy is corrected by velocity weighting factor so that it conducts dynamic regulation and reaches the speed of response. Homologous strategy is used according to the real-time data in the operation of automatic generation control. Results of simulation are perfect and power energy compensation control with ideal effect can be achieved in the particular duration.展开更多
In the new competitive environment of the electricity market, risk analysis is a powerful tool to guide investors under both contract uncertainties and energy prices of the spot market. Moreover, simulation of spot pr...In the new competitive environment of the electricity market, risk analysis is a powerful tool to guide investors under both contract uncertainties and energy prices of the spot market. Moreover, simulation of spot price scenarios and evaluation of energy contracts performance, are also necessary to the decision maker, and in particular to the trader to foresee opportunities and possible threats in the trading activity. In this context, computational systems that allow what-if analysis, involving simulation of spot price, contract portfolio optimization and risk evaluation are rather important. This paper proposes a decision support system not only for solving the problem of contracts portfolio optimization, by using linear programming, but also to execute risks analysis of the contracts portfolio performance, with VaR and CVaR metrics. Realistic tests have demonstrated the efficiency of this system.展开更多
文摘A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international literature has contributed to the understanding of the essential aspects to be verified regarding the quality of EIS, offering a wide spectrum of good practice examples related to the content of the studies. Even so, there is a need for empirical studies that allow the identification of specific aspects related to the context of application of the EIS, which could lead to the identification of opportunities to improve both the quality of the reports and also the effectiveness of EIA. Therefore, the present paper is focused on the quality review of a number of EIS submitted to the Brazilian Federal Environmental Agency (Ibama) to instruct the assessment of electric power transmission systems. Based on the application of the EIS quality review package as proposed by Lee and Colley (1992), the outcomes reveal opportunities for improving the scope of EIA, analysis of alternatives, prediction of magnitude and the assessment of impact significance. Finally, the development and/or adaptation of a similar tool for the systematic review of the quality of EIA reports is recommended.
基金funded by King Abdulaziz University,Jedda Saudi Arabia and King Abdulah City for Atomic and Renewable Energy,Riyadh,Saudi Arabia Grant No.(KCR-KFL-13-20)thereforethe authors gratefully acknowledge their technical and financial support.
文摘The economics,infrastructure,transportation,and level of living of a country are all influenced by energy.The gap between energy usage and availabil-ity is a global issue.Currently,all countries rely on fossil fuels for energy genera-tion,and these fossil fuels are not sustainable.The hydrogen proton exchange membrane fuel cell(PEMFC)power system is both clean and efficient.The fuel delivery system and the PEMFC make up the majority of the PEMFC power sys-tem.The lack of an efficient,safe,and cost-effective hydrogen storage system is still a major barrier to its widespread use.Solid hydrogen storage has the large capacity,safety and good reversibility.As a hydrogen source system,the hydro-gen supply characteristics affect the characteristics of the PEMFC at the output.In this paper,a mathematical model of a hydrogen source reactor and PEMFC based on chemical absorption/desorption of solid hydrogen storage is established,and a simulation model of a PEMFC power system coupled with solid hydrogen storage is established using MATLAB/SIMULINK software,and the hydrogen supply of the reactor is analyzed in detail.The influence of prominent factors is evaluated.The research results show that the proposed method improved the system perfor-mance.At the same time,increasing the PEMFC temperature,increasing the area of the proton exchange membrane and the oxygen supply pressure can increase the output power of the power system.
文摘The on-site inspection of high-power DC chargers results in new DC high-current measurement and DC energy traceability system requirements.This paper studies the traceability technology of electric energy value for automotive high-power DC chargers,including:(1)the traceability method of the built-in DC energy meter and shunt of the charger;(2)precision DC high current and small precision DC voltage output and measurement technology.This paper designs a 0.1 mA∼600 A DC high current measurement system and proposes a 0.005 level DC powermeasurement traceability system.The uncertainty evaluation experiment of theDC powermeasurement calibration system and the high-power DC charger’s on-site calibration experiment results verify the method’s effectiveness and feasibility in this paper.The experimental results show that the combined standard uncertainty of the DC power metering verification system can be 0.0451%.
文摘The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sources.One potential technology,the Microbial Fuel Cell(MFC)based on rice,vegetable,and fruit wastes,can convert chemical energy into electrical energy.This study aims to determine the potency of rice,vegetable,and fruit waste assisted by Cu/Mg electrodes as a generator of electricity.The method used was a laboratory experiment,including the following steps:electrode preparation,waste sample preparation,incubation of the waste samples,construction of a reactor using rice,vegetable,and fruit waste as a source of electricity,and testing.The tests included measuring electrical conductivity,electric current,voltage,current density,and power density.Based on the test results,the maximum current and voltage values for the fruit waste samples were 5.53 V and 11.5 mA,respectively,with a current density of 2.300 mA/cm^(2) and a power density of 12.719 mW/cm^(2).The results indicate the potential for a future development.The next step in development involves determining the optimum conditions for utilizing of rice,vegetable,and fruit waste.The results of the electrical conductivity test on rice,vegetable,and fruit waste samples were 1.51,2.88,and 3.98 mS,respectively,with the highest electrical conductivity value found in the fruit waste sample.
基金This work is supported by China Postdoctoral Science Foundation(2021M690798)Guizhou Province Science and Technology Plan Project(No.[2021]General 085)+1 种基金National Natural Science Foundation of China(No.61603034)the Fundamental Research Funds for the Central Universities(Nos.FRF-BD-19-002A,FRF-DF-20-14).
文摘With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new challenges to the operation of the grid.Firstly,A novel bidirectional interaction model is established based on modulation theory with nonlinear loads.Then,the electric energy measuring scheme of EVs for V2G is derived under the conditions of distorted power loads.The scheme is composed of fundamental electric energy,fundamental-distorted electric energy,distorted-fundamental electric energy and distorted electric energy.And the characteristics of each electric energy are analyzed.Finally,the correctness of the model and energy measurement method is verified by three simulation cases:the impact signals,the fluctuating signals,and the harmonic signals.
基金Supported by the National Basic Research Program of China under Grant Nos 2013CB921900 and 2014CB920900the National Natural Science Foundation of China under Grant No 11374021)(S.Yan,Z.Xie,J.-H,Chen)+1 种基金support from the Elemental Strategy Initiative conducted by the MEXT,Japana Grant-in-Aid for Scientific Research on Innovative Areas"Science of Atomic Layers"from JSPS
文摘The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus (BP) by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10 V/nm to 0.83 V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronies, thermoelectric power generation and thermal imaging.
基金Shanghai Municipal Science and Technology Commission, China (No. 033012017).
文摘A novel parallel hybrid electrical urban bus (PHEUB) configuration consisting of an extra one-way clutch and an automatic mechanical transmission (AMT) is taken as the study subject. An energy management strategy combining a logic threshold approach and an instantaneous optimization algorithm is proposed for the investigated PHEUB. The objective of the energy management strategy is to achieve acceptable vehicle performance and drivability requirements while simultaneously maximizing the engine fuel consumption and maintaining the battery state of charge in its operation range at all times. Under the environment of Matlab/Simulink, a computer simulation model for the PHEUB is constructed by using the model building method combining theoretical analysis and bench test data. Simulation and experiment results for China Typical Bus Driving Schedule at Urban District (CTBDS_UD) are obtained, and the results indicate that the proposed control strategy not only controls the hybrid system efficiently but also improves the fuel economy significantly.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11147158 and 11264020the Jiangxi Province Natural Science Foundation under Grant No 2010GQW0031the Jiangxi Province Scientific Research Program of the Education Bureau under Grant No GJJ12483
文摘The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD (T) method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect.
文摘This article aims at giving a contribution to the issue of accounting electrical energy sale and purchase agreements in accordance with the faithful representation principle. To this end, it must be ascertained whether electrical energy is bought/sold for an industrial use exclusively, so that the relevant transaction will be accounted as a normal purchase/sale, or through the lease of the relevant production plant, which would require the supply contract to be accounted in compliance with International Accounting Standards (IAS) 17 "Leasing". Alternatively, it must also be ascertained whether the relevant party is implementing financial trading strategies, as in such hypothesis, the supply contract is to be accounted as a financial instrument according to International Financial Reporting Standards (IFRS) 9/IAS 39 "Financial Instruments". Finally, the modalities used by a number of companies listed on European regulated markets to account such kind of contracts will be analyzed.
文摘This article puts forward an automatic recognition algorithm of electric energy meter lead seals: firstly, the image will be histogram equalization, smoothing, binaryzation pretreatment, then according to the image characteristics of text changes, the system can quickly and accurately segment image from complex background, finally the system extract different dimension and the feature of English and Arabia using digital projection transform coefficient method and to identify the corresponding number by BP neural network, solves the problem of automatic recognition of electric energy meter lead sealing.
文摘Considering the additional electric energy generated after the full operation of the underground hydropower station, the electric energy accommodation of the Three Gorges Project (TGP) is reviewed. It is .focused on the additional electricity accommodation, based on the research at the earl), stage. The electric energ), accommodation solutions ate recommended as that. based on the cost-benefit analysis of the power distribution area, the additional electric energy of the Three Gorges should be given ptqority to meet the needs at the supply end of Hubei and Chongqing. The results of this research has a reference value on the implementation of the Three Gorges electric power accommodation, after the further optimization of the transmission curves in both wet and dry seasons.
文摘Increased pollution levels have caused damage to our planet. Many scientists are now warning on the long term effects. Green houses gases causes more of the sunlight to be trapped within the Earth’s atmosphere and thus causing increased Earth temperature. Individuals, governments, and private entities are now acting on fixing this problem. One of the most promising solutions is installing an array of solar cells in residential areas. Doing so makes sense for areas with abundant sunlight as the dependency on the grid can be minimized and even completely illuminated while providing a feasible economic perspective at the same time. This paper presents the modelling of a residential setup as a complete system along with an electric vehicle. The modelled components include: Photovoltaic Cells, Home Load Usage, Electric Vehicle, High-Voltage battery as an energy storage, Boost, and Inverter. The presented analysis will help engineers and system designers do better cost analysis. The study can also be used as a basis for maximizing the solar energy usage and perform component optimization.
基金National Natural Science Foundation of China(No.51367010)Science and Technology Program of Gansu Province(No.17JR5RA083)+1 种基金Program for Excellent Team of Scientific Research of Lanzhou Jiaotong University(No.201701)Scientific Research Program of Colleges and Universities of Gansu Province(No.2016B-032)。
文摘Aiming at the shortcomings of the existing electric energy metering method,combining with the harmonic responsibility analysis model based on the reference impedance method and the idea of apparent power decomposition in IEEE Std 1459-2010 standard,two new metering indicators—billing active power and billing power factor are defined.A new electric energy metering method is proposed and its specific implementation steps are given.The simulation model is built in Matlab/Simulink,and three different examples are set up.Using the simulation data,the various metering indicators need to be examined by the existing electric energy metering method and the new electric energy metering method are calculated.The calculation results show that the new electric energy metering method not only overcomes the shortcomings of the existing electric energy metering method,but also is very easy to be popularized and applied.
文摘Along with the massive applications of the non-linear loads and the impact loads, many non-stationary stochastic signals such as harmonics, inter-harmonics, impulse signals and so on are introduced into the electric network, and these non-stationary stochastic signals have had effects on the accuracy of the measurement of electric energy. The traditional method like Fourier Analysis can he applied efficiently on the stationary stochastic signals, hut it has little effect on non-stationary stochastic signals. In light of this, the form of the signals of the electric network in wavelet domain will he discussed in this paper. A measurement method of active power based on multi-resolution analysis in the stochastic process is presented. This method has a wider application scope compared with the traditional method Fourier analysis, and it is of good referential value and practical value in terms of raising the level of the existing electric energy measurement.
文摘The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing supply chain and related activities into a value network (VN). Previous researches on crowd value network concepts focus on the activities of infrastructure and load management and neglect activities that generate collaboration. Collaboration with and within crowds particularly demands a different mindset and management of sharing values, information, benefit, and risks. Furthermore, these concepts must integrate technical, processual, and social aspects. Thus, this article proposes a holistic framework of electricity VN management for crowd energy. It redefines VN activities for infrastructure and load management while appending VN activities for social electricity handling. Additionally, the framework illustrates the interactions among these three elements and concludes with an adaption cycle for the crowd value network.
文摘Over all fuel condition and the money we spend on the said fuel leads us to think about savings. What can we do? As individuals, we can educate our students and their family members. The easiest way to do that is to monitor their weekly spending for them. Together with their family members, the students have to monitor the consumption of electrical energy through three weeks. In the first week, they should spend electricity as they do everyday. During the second week they have the increase of spending of electrical energy. The third week is the saving energy week. They have to make a plan with their family members on how to save energy, for example, turning offthe lights in the empty rooms, turning offthe TV when there is no one watching it, etc.. Every week they have to note the data in kilowatts. When they acquire all the information and transform it into money they can see if it's worth saving electrical energy or not. They will see they don't have to give up the comforts of the modern life. The value of the project is in the fact that many households continue with the electrical energy saving. In fact, the number of the households is increasing.
文摘<span style="font-family:Verdana;">Today, energy is a vital component in the functioning of a hospital. Hospital technical facilities have several types of technologies, these include appliances for use;examination apparatus. So, for Quality Health Care in a hospital, there is</span><span style="font-family:Verdana;"> a</span><span style="font-family:Verdana;"> need to ensure the proper functioning of hospital equipment. In addition to the required maintenance as specified by the device manufacturer, </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">quality of the electrical energy across the device must be ensured. This article is an analysis of the quality of electric energy at the substation of National Hospital of Niamey. Thereby, the data collection, followed by the data processing and analysis revealed the parameters characterizing the quality of electrical energy across the substation. Our studies have shown that the substation is underutilized as the maximum inrush current is less than half the available current. </span><span style="font-family:Verdana;">The </span><span style="font-family:Verdana;">current </span><span style="font-family:Verdana;">was </span><span style="font-family:Verdana;">consumed by the three phases ha</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> resulted </span><span style="font-family:Verdana;">in</span><span style="font-family:Verdana;"> a strong current unbalance (230</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">A). However, the current unbalance and the voltage amplitude</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> are admissible according</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> base on EN50160 standard. Furthermore, the harmonics voltages present in this medium </span><span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> in the accepted range (1.8%) according to IEEE 519 standard. However, the fundamental frequency does not meet the standard, but the difference obtained has no adverse effect.</span>
文摘The urgent need for sustainable energy choices, local sustainable value creation, and reduction of import dependencies and non-sustainable resource use in Namibia cannot be over emphasised. This study was conducted with the ultimate goal to provide the basis for accurate energy fuel mix and climate change monitoring, and reporting and planning for addressing a global problem at local/domestic level. The energy consumption and production data for the country were used with International Panel on Climate Change (IPCC) and International Energy Agency (IEA) conversions, and carbon footprint calculation tools to determine the GHG emissions and air pollutants per type of energy fuel;and the carbon footprint associated with each energy fuel option for the country. The study showed that: 1) there is no single energy fuel which is not associated with GHG emissions and/or other environmental implications;2) increase in population and energy consumption and production yields increase in GHGs and other major pollutants (SO<sub>x</sub>, NO<sub>x</sub>, Particulate Matter);and 3) the choice of fuel mix determines the success of GHG emissions reduction. A future energy mix dominated by renewable energy technologies;and a balanced view of the actual benefits of the Namibian energy supply choices was also recommended.
文摘An automatic generation control strategy based on balance of daily total electric energy is put forward. It makes the balance between actual total generated energy controlled by automatic generation system and planned total energy on base of area control error, and makes the actual 24-hour active power load curve to approach the planned load curve. The generated energy is corrected by velocity weighting factor so that it conducts dynamic regulation and reaches the speed of response. Homologous strategy is used according to the real-time data in the operation of automatic generation control. Results of simulation are perfect and power energy compensation control with ideal effect can be achieved in the particular duration.
文摘In the new competitive environment of the electricity market, risk analysis is a powerful tool to guide investors under both contract uncertainties and energy prices of the spot market. Moreover, simulation of spot price scenarios and evaluation of energy contracts performance, are also necessary to the decision maker, and in particular to the trader to foresee opportunities and possible threats in the trading activity. In this context, computational systems that allow what-if analysis, involving simulation of spot price, contract portfolio optimization and risk evaluation are rather important. This paper proposes a decision support system not only for solving the problem of contracts portfolio optimization, by using linear programming, but also to execute risks analysis of the contracts portfolio performance, with VaR and CVaR metrics. Realistic tests have demonstrated the efficiency of this system.