Uganda launches giant China-constructed hydropower plant to bolster its electricity supply,and also assist South Sudan with theirs Ugandans and South Sudanese have had their lives lit up by the steady flow of electric...Uganda launches giant China-constructed hydropower plant to bolster its electricity supply,and also assist South Sudan with theirs Ugandans and South Sudanese have had their lives lit up by the steady flow of electricity from a massive hydropower infrastructure project,constructed by one of China’s leading contractors.展开更多
China helps to diversify Zambia’s energy output to tackle chronic electricity shortages Innocent Gondwe tries to put up a smile as he uses his welding machine anxiously to finish his work in time in order to get paid...China helps to diversify Zambia’s energy output to tackle chronic electricity shortages Innocent Gondwe tries to put up a smile as he uses his welding machine anxiously to finish his work in time in order to get paid,before a scheduled power cut.But he is unable to fully hide the pain in his eyes caused by the frequent power cuts that are a!ecting his business,which solely depends on electricity supply from ZESCO,Zambia’s major power utility company.After dropping out of school,Gondwe went all out to establish himself as an artisan to earn a living in Kalingalinga,one of the slums in Lusaka,Zambia’s capital.展开更多
16 September 2013, Shenzhen--ZTE today unveiled the world's first flexible, reconfigurable terabit router that allows customers to build the highest-performance broadband networks. The terabit router supports the de...16 September 2013, Shenzhen--ZTE today unveiled the world's first flexible, reconfigurable terabit router that allows customers to build the highest-performance broadband networks. The terabit router supports the deployment of multiple line cards with processing capabilities of 10 Gbps to 1 Tbps. It also supports the deployment of modules that can scale throughput from 200 Gbps to 18 Tbps. For easy installation in a range of environments, the router interfaces are flexible and the component design is loose-coupled. This allows customers to customize networks to their needs and promotes adaptability, consistency, and continuity.展开更多
MORE than 1,000 Ghanaians are benefiting directly by way of jobs from a $600 million Sunon Asogli Thermal Power Plant (Ghana) Limited project - a power generating plant established in the Kpone-Tema metropolis, one ...MORE than 1,000 Ghanaians are benefiting directly by way of jobs from a $600 million Sunon Asogli Thermal Power Plant (Ghana) Limited project - a power generating plant established in the Kpone-Tema metropolis, one of the highly industrialized metropolitan areas in Ghana.展开更多
1.Background The use of engineering tools,design,research,and thinking to create environments and capabilities whereby individuals who are currently under-employed or unemployed due to a physical disability(e.g.,amput...1.Background The use of engineering tools,design,research,and thinking to create environments and capabilities whereby individuals who are currently under-employed or unemployed due to a physical disability(e.g.,amputation or spinal cord injury)or neurological difference(e.g.,autism)are enabled to become fully productive and employed members of society has been the implicit goal of decades of research at Vanderbilt University and elsewhere.At Vanderbilt University,progress in these areas has been greatly facilitated by the proximity of the School of Engineering to the world-class Vanderbilt University Medical Center and the resulting close collaboration between engineering and medical researchers.展开更多
Data management experts met on September 21,2020 in Beijing and online at the 2020 National Big Data Standardization Conference and the 7th plenary meeting of the big data working group of National Information Securit...Data management experts met on September 21,2020 in Beijing and online at the 2020 National Big Data Standardization Conference and the 7th plenary meeting of the big data working group of National Information Security Standardization Technical Committee(SAC/TC 28),sharing and exchanging the progress and prospects in the area.展开更多
There are abound with the deconstruction of classic works in recent years,among which Updike’s Gertrude and Claudius is undoubtedly an impressive one.Updike completed the antecedent part of Shakespeare’s play Hamlt....There are abound with the deconstruction of classic works in recent years,among which Updike’s Gertrude and Claudius is undoubtedly an impressive one.Updike completed the antecedent part of Shakespeare’s play Hamlt.Noticeably,this new prequel of Hamlet,from the mindset of female,takes Queen Gertrude as the narrative center and airs Gertrude’s psychological states to break the confinement of female discourse in Shakespeare’s plays.Hinged on Foucault’s theory of power and discourse,this paper attempts to analyze how Updike manifests women’s endeavors to assert preserve and construct their discourse,break the aphasia and even challenge the voice of male authority by elucidating the interactions between Queen Gertrude and other crucial male roles in the full text in order to navigate readers in-depth to scrutinize the changes of women’s social status in different era.展开更多
Female NPC deputies from ethnic minority groups stand out.China's most significant annual political event,known as the Two Sessions,commenced in Beijing on March 4,bringing together thousands of deputies to the 14...Female NPC deputies from ethnic minority groups stand out.China's most significant annual political event,known as the Two Sessions,commenced in Beijing on March 4,bringing together thousands of deputies to the 14th National People's Congress(NPC),the country's top legislature,and members of the 14th Chinese People's Political Consultative Conference(CPPCC)National Committee.展开更多
As a new branch of efficient and low-cost mechanical energy conversion technology,triboelectric nanogenerator(TENG)is a potential solution to provide a long-term power supply for the Internet of Things(IoT)sensors and...As a new branch of efficient and low-cost mechanical energy conversion technology,triboelectric nanogenerator(TENG)is a potential solution to provide a long-term power supply for the Internet of Things(IoT)sensors and portable electronic devices.However,due to inherent working properties of TENG itself such as extremely high internal impedance,pulse,and alternating current(AC)output,TENG can not directly supply power to loads such as batteries efficiently.Based on these,we describe TENG’s performance from a new perspective of powering ability.It consists of two aspects:the ability to transport charge effectively and the ability to output high power quality current steadily.In order to push forward the developments and applications of TENG,it is necessary to improve its power supply capacity from different perspectives.Fortunately,in recent years,a variety of output signal’s management strategies aiming at effectively managing the generated electricity and significantly improving powering ability of TENG have obtained significantly progress.Herein,this paper discusses the working mechanisms and different load characteristics of TENG at first to clarify the electric performance of TENG.Then,on basis of theoretical analysis,the output signal’s management strategies are elaborated from four aspects:improving the cycle output electricity of TENG,increasing the surface charge density of TENG,improving the power quality of TENG-based energy harvesting system,promoting the application of TENG through integrated circuit(IC)technology and TENG network,and the relevant principles and applications are discussed systematically.Finally,the advantages and disadvantages of the above output signal’s management strategies are summarized and discussed,and the future development of the output signal’s management strategies for TENG is prospected.展开更多
Inductive pulsed power supply(IPPS)is a promising type of power supplies for electromagnetic launch,but its advantage in energy density is strongly restricted by the primary power source.Fortunately,batteries become a...Inductive pulsed power supply(IPPS)is a promising type of power supplies for electromagnetic launch,but its advantage in energy density is strongly restricted by the primary power source.Fortunately,batteries become a suitable and practical choice for the primary source.In this paper,the working process of battery powering IPPS is analysed in detail.Various indicators of the charging performance are calculated,which are then proved to be irrelevant to most of the parameters of IPPS.Based on this,an optimization method for battery and IPPS system is proposed,in which the charging and discharging processes can be decoupled.And for the decoupled battery charging process,the bi-objective optimization model is suggested.Several examples illustrate the feasibility and effectiveness of the proposed optimization methods.In order to further improve the performance of the battery and IPPS system,the inherent time constant of the inductors and the output power density of the battery cell should be increased.展开更多
Silicon carbide(SiC) power modules play an essential role in the electric vehicle drive system. To improve their performance, reduce their size, and increase production efficiency, this paper proposes a multiple stake...Silicon carbide(SiC) power modules play an essential role in the electric vehicle drive system. To improve their performance, reduce their size, and increase production efficiency, this paper proposes a multiple staked direct bonded copper(DBC) unit based power module packaging method to parallel more chips. This method utilizes mutual inductance cancellation effect to reduce parasitic inductance. Because the conduction area in the new package is doubled, the overall area of power module can be reduced. Entire power module is divided into smaller units to enhance manufacture yield, and improve design freedom. This paper provides a detailed design, analysis and fabrication procedure for the proposed package structure. Additionally, this paper offers several feasible solutions for the connection between power terminals and DBC untis. With the structure, 18dies were paralleled for each phase-leg in a econodual size power module. Both simulation and double pulse test results demonstrate that, compared to conventional layouts, the proposed package method has 74.8% smaller parasitic inductance and 34.9% lower footprint.展开更多
The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone t...The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue failure.The structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue evaluation.Here,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural stress.Besides,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into account.The research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.展开更多
A 320 MW old steam power plant has been chosen for repowering in this paper. Considering the technical conditions and working life of the power plant, the full repowering method has been selected from different repowe...A 320 MW old steam power plant has been chosen for repowering in this paper. Considering the technical conditions and working life of the power plant, the full repowering method has been selected from different repowering methods. The power plant repower- ing has been analyzed for three different feed water flow rates: a flow rate equal to the flow rate at the condenser exit in the original plant when it works at nominal load, a flow rate at maximum load, and a flow rate when all the extractions are blocked. For each flow rates, two types of gas turbines have been examined: V94.2 and V94.3A. The effect of a duct burner has then been investigated in each of the above six cases. Steam is produced by a double- pressure heat recovery steam generator (HRSG) with reheat which obtains its required heat from the exhaust gases coming from the gas turbines. The results obtained from modeling and analyzing the energy-exergy of the original steam power plant and the repowered power plant indicate that the maximum efficiency of the repowered power plant is 52.04%. This maximum efficiency occurs when utilizing two V94.3A gas turbines without duct burner in the steam flow rate of the nominal load.展开更多
Owing to the persisting hype in pushing toward global carbon neutrality,the study scope of atmospheric science is rapidly expanding.Among numerous trending topics,energy meteorology has been attracting the most attent...Owing to the persisting hype in pushing toward global carbon neutrality,the study scope of atmospheric science is rapidly expanding.Among numerous trending topics,energy meteorology has been attracting the most attention hitherto.One essential skill of solar energy meteorologists is solar power curve modeling,which seeks to map irradiance and auxiliary weather variables to solar power,by statistical and/or physical means.In this regard,this tutorial review aims to deliver a complete overview of those fundamental scientific and engineering principles pertaining to the solar power curve.Solar power curves can be modeled in two primary ways,one of regression and the other of model chain.Both classes of modeling approaches,alongside their hybridization and probabilistic extensions,which allow accuracy improvement and uncertainty quantification,are scrutinized and contrasted thoroughly in this review.展开更多
Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified ...Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified railways toward high-efficiency and resilience but also an inevitable requirement to achieve carbon neutrality target.On the basis of sorting out the power supply structures of conventional AC and DC modes,this paper first reviews the characteristics of the existing TPSs,such as weak power supply flexibility and low-energy efficiency.Furthermore,the power supply structures of various TPSs for future electrified railways are described in detail,which satisfy longer distance,low-carbon,high-efficiency,high-reliability and high-quality power supply requirements.Meanwhile,the application prospects of different traction modes are discussed from both technical and economic aspects.Eventually,this paper introduces the research progress of mixed-system electrified railways and traction power supply technologies without catenary system,speculates on the future development trends and challenges of TPSs and predicts that TPSs will be based on the continuous power supply mode,employing power electronic equipment and intelligent information technology to construct a railway comprehensive energy system with renewable energy.展开更多
As a clean and renewable form of energy,photovoltaic(PV)power generation converts solar energy into electrical energy,reducing the consumption of fossil fuels and significantly lowering greenhouse gas emissions.Amidst...As a clean and renewable form of energy,photovoltaic(PV)power generation converts solar energy into electrical energy,reducing the consumption of fossil fuels and significantly lowering greenhouse gas emissions.Amidst the global transition towards cleaner forms of energy,countries all around the world are vigorously developing PV technology.展开更多
文摘Uganda launches giant China-constructed hydropower plant to bolster its electricity supply,and also assist South Sudan with theirs Ugandans and South Sudanese have had their lives lit up by the steady flow of electricity from a massive hydropower infrastructure project,constructed by one of China’s leading contractors.
文摘China helps to diversify Zambia’s energy output to tackle chronic electricity shortages Innocent Gondwe tries to put up a smile as he uses his welding machine anxiously to finish his work in time in order to get paid,before a scheduled power cut.But he is unable to fully hide the pain in his eyes caused by the frequent power cuts that are a!ecting his business,which solely depends on electricity supply from ZESCO,Zambia’s major power utility company.After dropping out of school,Gondwe went all out to establish himself as an artisan to earn a living in Kalingalinga,one of the slums in Lusaka,Zambia’s capital.
文摘16 September 2013, Shenzhen--ZTE today unveiled the world's first flexible, reconfigurable terabit router that allows customers to build the highest-performance broadband networks. The terabit router supports the deployment of multiple line cards with processing capabilities of 10 Gbps to 1 Tbps. It also supports the deployment of modules that can scale throughput from 200 Gbps to 18 Tbps. For easy installation in a range of environments, the router interfaces are flexible and the component design is loose-coupled. This allows customers to customize networks to their needs and promotes adaptability, consistency, and continuity.
文摘MORE than 1,000 Ghanaians are benefiting directly by way of jobs from a $600 million Sunon Asogli Thermal Power Plant (Ghana) Limited project - a power generating plant established in the Kpone-Tema metropolis, one of the highly industrialized metropolitan areas in Ghana.
基金support has been provided by US National Science Foundation(OIA-1936970)a Howard Hughes Medical Institute professorship award.
文摘1.Background The use of engineering tools,design,research,and thinking to create environments and capabilities whereby individuals who are currently under-employed or unemployed due to a physical disability(e.g.,amputation or spinal cord injury)or neurological difference(e.g.,autism)are enabled to become fully productive and employed members of society has been the implicit goal of decades of research at Vanderbilt University and elsewhere.At Vanderbilt University,progress in these areas has been greatly facilitated by the proximity of the School of Engineering to the world-class Vanderbilt University Medical Center and the resulting close collaboration between engineering and medical researchers.
文摘Data management experts met on September 21,2020 in Beijing and online at the 2020 National Big Data Standardization Conference and the 7th plenary meeting of the big data working group of National Information Security Standardization Technical Committee(SAC/TC 28),sharing and exchanging the progress and prospects in the area.
文摘There are abound with the deconstruction of classic works in recent years,among which Updike’s Gertrude and Claudius is undoubtedly an impressive one.Updike completed the antecedent part of Shakespeare’s play Hamlt.Noticeably,this new prequel of Hamlet,from the mindset of female,takes Queen Gertrude as the narrative center and airs Gertrude’s psychological states to break the confinement of female discourse in Shakespeare’s plays.Hinged on Foucault’s theory of power and discourse,this paper attempts to analyze how Updike manifests women’s endeavors to assert preserve and construct their discourse,break the aphasia and even challenge the voice of male authority by elucidating the interactions between Queen Gertrude and other crucial male roles in the full text in order to navigate readers in-depth to scrutinize the changes of women’s social status in different era.
文摘Female NPC deputies from ethnic minority groups stand out.China's most significant annual political event,known as the Two Sessions,commenced in Beijing on March 4,bringing together thousands of deputies to the 14th National People's Congress(NPC),the country's top legislature,and members of the 14th Chinese People's Political Consultative Conference(CPPCC)National Committee.
基金funded by the National Key R&D Project from Minister of Science and Technology(No.2021YFA1201602)the National Natural Science Foundation of China(Nos.52172203 and U21A20175).
文摘As a new branch of efficient and low-cost mechanical energy conversion technology,triboelectric nanogenerator(TENG)is a potential solution to provide a long-term power supply for the Internet of Things(IoT)sensors and portable electronic devices.However,due to inherent working properties of TENG itself such as extremely high internal impedance,pulse,and alternating current(AC)output,TENG can not directly supply power to loads such as batteries efficiently.Based on these,we describe TENG’s performance from a new perspective of powering ability.It consists of two aspects:the ability to transport charge effectively and the ability to output high power quality current steadily.In order to push forward the developments and applications of TENG,it is necessary to improve its power supply capacity from different perspectives.Fortunately,in recent years,a variety of output signal’s management strategies aiming at effectively managing the generated electricity and significantly improving powering ability of TENG have obtained significantly progress.Herein,this paper discusses the working mechanisms and different load characteristics of TENG at first to clarify the electric performance of TENG.Then,on basis of theoretical analysis,the output signal’s management strategies are elaborated from four aspects:improving the cycle output electricity of TENG,increasing the surface charge density of TENG,improving the power quality of TENG-based energy harvesting system,promoting the application of TENG through integrated circuit(IC)technology and TENG network,and the relevant principles and applications are discussed systematically.Finally,the advantages and disadvantages of the above output signal’s management strategies are summarized and discussed,and the future development of the output signal’s management strategies for TENG is prospected.
基金National Natural Science Foundation of China,Grant/Award Number:61877063。
文摘Inductive pulsed power supply(IPPS)is a promising type of power supplies for electromagnetic launch,but its advantage in energy density is strongly restricted by the primary power source.Fortunately,batteries become a suitable and practical choice for the primary source.In this paper,the working process of battery powering IPPS is analysed in detail.Various indicators of the charging performance are calculated,which are then proved to be irrelevant to most of the parameters of IPPS.Based on this,an optimization method for battery and IPPS system is proposed,in which the charging and discharging processes can be decoupled.And for the decoupled battery charging process,the bi-objective optimization model is suggested.Several examples illustrate the feasibility and effectiveness of the proposed optimization methods.In order to further improve the performance of the battery and IPPS system,the inherent time constant of the inductors and the output power density of the battery cell should be increased.
基金supported in part by National Key R&D Program of China (2021YFB2500600)CAS Youth multi-discipline project (JCTD-2021-09)Strategic Piority Research Program of Chinese Academy of Sciences (XDA28040100)。
文摘Silicon carbide(SiC) power modules play an essential role in the electric vehicle drive system. To improve their performance, reduce their size, and increase production efficiency, this paper proposes a multiple staked direct bonded copper(DBC) unit based power module packaging method to parallel more chips. This method utilizes mutual inductance cancellation effect to reduce parasitic inductance. Because the conduction area in the new package is doubled, the overall area of power module can be reduced. Entire power module is divided into smaller units to enhance manufacture yield, and improve design freedom. This paper provides a detailed design, analysis and fabrication procedure for the proposed package structure. Additionally, this paper offers several feasible solutions for the connection between power terminals and DBC untis. With the structure, 18dies were paralleled for each phase-leg in a econodual size power module. Both simulation and double pulse test results demonstrate that, compared to conventional layouts, the proposed package method has 74.8% smaller parasitic inductance and 34.9% lower footprint.
基金financially supported by the Director Fund of National Energy Deepwater Oil and Gas Engineering Technology Research and Development Center(Grant No.KJQZ-2024-2103)。
文摘The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue failure.The structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue evaluation.Here,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural stress.Besides,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into account.The research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.
文摘A 320 MW old steam power plant has been chosen for repowering in this paper. Considering the technical conditions and working life of the power plant, the full repowering method has been selected from different repowering methods. The power plant repower- ing has been analyzed for three different feed water flow rates: a flow rate equal to the flow rate at the condenser exit in the original plant when it works at nominal load, a flow rate at maximum load, and a flow rate when all the extractions are blocked. For each flow rates, two types of gas turbines have been examined: V94.2 and V94.3A. The effect of a duct burner has then been investigated in each of the above six cases. Steam is produced by a double- pressure heat recovery steam generator (HRSG) with reheat which obtains its required heat from the exhaust gases coming from the gas turbines. The results obtained from modeling and analyzing the energy-exergy of the original steam power plant and the repowered power plant indicate that the maximum efficiency of the repowered power plant is 52.04%. This maximum efficiency occurs when utilizing two V94.3A gas turbines without duct burner in the steam flow rate of the nominal load.
基金supported by the National Natural Science Foundation of China(project no.42375192),and the China Meteorological Administration Climate Change Special Program(CMA-CCSPproject no.QBZ202315)+2 种基金supported by the National Natural Science Foundation of China(project no.42030608)supported by the National Research,Development and Innovation Fund,project no.OTKA-FK 142702by the Hungarian Academy of Sciences through the Sustainable Development and Technologies National Programme(FFT NP FTA)and the János Bolyai Research Scholarship.
文摘Owing to the persisting hype in pushing toward global carbon neutrality,the study scope of atmospheric science is rapidly expanding.Among numerous trending topics,energy meteorology has been attracting the most attention hitherto.One essential skill of solar energy meteorologists is solar power curve modeling,which seeks to map irradiance and auxiliary weather variables to solar power,by statistical and/or physical means.In this regard,this tutorial review aims to deliver a complete overview of those fundamental scientific and engineering principles pertaining to the solar power curve.Solar power curves can be modeled in two primary ways,one of regression and the other of model chain.Both classes of modeling approaches,alongside their hybridization and probabilistic extensions,which allow accuracy improvement and uncertainty quantification,are scrutinized and contrasted thoroughly in this review.
基金supported in part by the Scientific Foundation for Outstanding Young Scientists of Sichuan under Grant No.2021JDJQ0032in part by the National Natural Science Foundation of China under Grant No.52107128in part by the Natural Science Foundation of Sichuan Province under Grant No.2022NSFSC0436.
文摘Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified railways toward high-efficiency and resilience but also an inevitable requirement to achieve carbon neutrality target.On the basis of sorting out the power supply structures of conventional AC and DC modes,this paper first reviews the characteristics of the existing TPSs,such as weak power supply flexibility and low-energy efficiency.Furthermore,the power supply structures of various TPSs for future electrified railways are described in detail,which satisfy longer distance,low-carbon,high-efficiency,high-reliability and high-quality power supply requirements.Meanwhile,the application prospects of different traction modes are discussed from both technical and economic aspects.Eventually,this paper introduces the research progress of mixed-system electrified railways and traction power supply technologies without catenary system,speculates on the future development trends and challenges of TPSs and predicts that TPSs will be based on the continuous power supply mode,employing power electronic equipment and intelligent information technology to construct a railway comprehensive energy system with renewable energy.
文摘As a clean and renewable form of energy,photovoltaic(PV)power generation converts solar energy into electrical energy,reducing the consumption of fossil fuels and significantly lowering greenhouse gas emissions.Amidst the global transition towards cleaner forms of energy,countries all around the world are vigorously developing PV technology.