Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test b...Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test bench is combined with meas-ured or predicted transfer functions.It is important,however,to allow for installation effects due to shielding by fairings or the train body.In the current work,fast-running analytical models are developed to determine these installation effects.The model for roof-mounted sources takes account of diffraction at the corner of the train body or fairing,using a barrier model.For equipment mounted under the train,the acoustic propagation from the sides of the source is based on free-field Green’s functions.The bottom surfaces are assumed to radiate initially into a cavity under the train,which is modelled with a simple diffuse field approach.The sound emitted from the gaps at the side of the cavity is then assumed to propagate to the receivers according to free-field Green’s functions.Results show good agreement with a 2.5D boundary element model and with measurements.Modelling uncertainty and parametric uncertainty are evaluated.The largest variability occurs due to the height and impedance of the ground,especially for a low receiver.This leads to standard deviations of up to 4 dB at low frequencies.For the roof-mounted sources,uncertainty over the location of the corner used in the equivalent barrier model can also lead to large standard deviations.展开更多
Avivid three-dimensional rendering of a bridge appeared on the intelligent monitor and evaluation platform at Beijing Yunlu Technology Co.,Ltd.,pointing to key factors of bridge health.Real-time status,events,transpor...Avivid three-dimensional rendering of a bridge appeared on the intelligent monitor and evaluation platform at Beijing Yunlu Technology Co.,Ltd.,pointing to key factors of bridge health.Real-time status,events,transportation navigation,and traffic conditions were all tracked on the screen.Numerous sensors installed on bridge track every minor dynamic change on the bridge surface and perform digital analysis.展开更多
The positive figures of last year confirm the strength,resilience,and prospects of the Chinese economy.CHINA’S government work report delivered to the 2024“Two Sessions”in early March released some important statis...The positive figures of last year confirm the strength,resilience,and prospects of the Chinese economy.CHINA’S government work report delivered to the 2024“Two Sessions”in early March released some important statistics.The GDP surpassed RMB 126 trillion,an increase of 5.2 percent.A total of 12.44 million urban jobs were added,and the average surveyed urban unemployment rate stood at 5.2 percent by average.The consumer price index(CPI)rose by 0.2 percent.The production and sales of new-energy vehicles accounted for over 60 percent of the world’s total.Grain output hit a record high of 695 million tonnes.The installed renewable energy capacity surpassed its thermal power for the first time in Chinese history,accounting for over half of newly installed renewable energy capacity worldwide.The per capita disposable income of residents also rose by 6.1 percent nationwide.展开更多
"In 2023,China's photovoltaic industry continued to maintain a rapid development momentum,with an additional installed capacity of more than 216 GW,accounting for more than half of the global total.The cumula..."In 2023,China's photovoltaic industry continued to maintain a rapid development momentum,with an additional installed capacity of more than 216 GW,accounting for more than half of the global total.The cumulative installed capacity is close to 610 GW,which helps the installed capacity of renewable energy surpass that of thermal power historically.In 2023,the output value of the domestic photovoltaic manufacturing industry exceeded RMB1.75 trillion,a year-on-year increase of 17.1%,and the output of the four main industrial chains of polysilicon.展开更多
Translation of specialized documents in optometry presents unique challenges,requiring a deep understanding of the professional context,terminology,and adherence to specific translation styles.This paper delves into t...Translation of specialized documents in optometry presents unique challenges,requiring a deep understanding of the professional context,terminology,and adherence to specific translation styles.This paper delves into the translation theory and techniques employed in the English-to-Chinese translation of the“Optoform 80 Installation and Maintenance Manual”,serving as a case study.Emphasizing Nida’s theory of functional equivalence,the paper explores the complexities of translating professional optometry literature,focusing on key points and common issues in translating installation and maintenance manuals for optometric devices.Special attention is given to the translation of professional terminology,employing methods such as addition,omission,conversion,and repetition.The translation process aims to meet specific requirements,ensuring accuracy and coherence while aligning with Chinese language conventions.The paper also analyzes translation methods and techniques concerning terminology,prepositions,conjunctions,and handling parallel elements based on practical insights from the Optoform 80 Manual.展开更多
Various industries today rely on the support of electromechanical equipment,expanding its scope of application and leading to an increase in electromechanical installation projects.However,due to the high level of exp...Various industries today rely on the support of electromechanical equipment,expanding its scope of application and leading to an increase in electromechanical installation projects.However,due to the high level of expertise required and the potential risks involved,it is crucial to emphasize safety management during construction.This paper delves into the significance of construction safety management for electromechanical installation projects,identifies common problems encountered during construction,and proposes solutions.This analysis aims to provide relevant personnel with essential guidance and references for managing electromechanical installation projects safely.展开更多
“Alone together”is an ever-changing“wicked problem.”In this research and practice,the author tries to combine experience design,referring to the theory of“interaction ritual chain theory,”and creatively add inte...“Alone together”is an ever-changing“wicked problem.”In this research and practice,the author tries to combine experience design,referring to the theory of“interaction ritual chain theory,”and creatively add interactive experience to discursive works,so that the audience can think between the real and the virtual.展开更多
Here are some of the achievements China made in 2023:GDP exceeded 126 trillion yuan($17.43 trillion)with a growth of 5.2 percent;12.44 million new urban jobs were created;average surveyed unemployment rate in urban ar...Here are some of the achievements China made in 2023:GDP exceeded 126 trillion yuan($17.43 trillion)with a growth of 5.2 percent;12.44 million new urban jobs were created;average surveyed unemployment rate in urban areas was 5.2 percent;consumer price index increased by 0.2 percent;new energy vehicle production and sales accounted for more than 60 percent of the global share;grain output reached a record high of 695 billion kg;installed renewable energy capacity surpassed thermal power capacity for the first time in history,and China accounted for over half of newly installed renewable energy capacity worldwide;per-capita disposable income of residents increased by 6.1 percent…展开更多
Digital media art is an emerging art form that combines digital technology and media art.It has huge potential to bring innovation to urban public spaces and provide them with vibrant artistic experiences.This article...Digital media art is an emerging art form that combines digital technology and media art.It has huge potential to bring innovation to urban public spaces and provide them with vibrant artistic experiences.This article analyzes the design significance and value of digital media art in urban public space,its various forms of application in urban public space design,and the innovative ideas and paths that digital media art can take in urban public space to guide the future.The application and innovative methods of digital media art in urban public space design provide certain theoretical and practical references for urban planners and designers.展开更多
To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction tec...To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction technology.These aspects include the lightning protection classification of buildings,air terminals,down conductors,grounding devices,division of lightning protection zones,and lightning electromagnetic pulse shielding.Through the introduction of this article,readers can gain a comprehensive understanding of the application and value of lightning protection grounding construction technology in building electrical installation projects.展开更多
Compliant vertical access risers(CVAR)have broad application prospects in deep-water oil and gas transportation.However,the mechanical behaviors of the CVAR with a variable length during installation remains unclear.T...Compliant vertical access risers(CVAR)have broad application prospects in deep-water oil and gas transportation.However,the mechanical behaviors of the CVAR with a variable length during installation remains unclear.To address this issue,based on the flexible segment method,a model of CVAR with a variable length during installation is established in this study,which is verified by the comparison with commercial software.Then,the mechanical behaviors of CVAR during installation are investigated.The results reveal that the CVAR configuration is significantly affected by the buoyancy blocks.The streamwise displacement of CVAR increases with the increase of current velocity.When the BOP weight is insuffcient,obvious upbending is observed in the lower region and transition region,leading to local compression.When the platform moves in the opposite direction to the current,the maximum stress is larger than that of the scenario when the platform moves in the same direction as the current.展开更多
Suction caissons are widely used for anchoring floating platform and offshore wind turbines.Penetration of the suction caisson into the desired position under the combination of its self-weight and applied suction res...Suction caissons are widely used for anchoring floating platform and offshore wind turbines.Penetration of the suction caisson into the desired position under the combination of its self-weight and applied suction resulted from pumping out the encased water is integral to practical engineering.Model tests were carried out to investigate the suctionassisted installation of suction caissons in clay under various undrained shear strengths.It was found that there exists a critical penetration depth value.When the penetration depth is smaller than the critical value,the soil plug undrained shear strength is higher than intact clay(i.e.,clay prior to installation).However,when the penetration depth is greater than the critical penetration depth,the undrained shear strength of soil plug is lower than intact clay.The critical value decreases with the increasing consolidation time and undrained shear strength of clay.During suction-assisted installation,cracks occur around suction caissons.The installation way has little effect on the crack formation.The influence range(i.e.,the maximum distance between the crack and the suction caisson edge)was found to increase with the increasing friction coefficient of interface between the suction caisson wall and soil and decreases with the increasing soil undrained shear strength.In addition,the drained condition of the clay during installation is dominated by the caisson aspect ratio,the undrained shear strength and the friction coefficient between the caisson wall and clay.Equations to estimate the penetration resistance and the required suction to install the suction caisson are summarized.展开更多
This paper presents the results of numerical simulation of plasma equilibrium and stability in the MEPHIST-0 tokamak with SIEMNED software and comparison of simulation results with experiments.The determined character...This paper presents the results of numerical simulation of plasma equilibrium and stability in the MEPHIST-0 tokamak with SIEMNED software and comparison of simulation results with experiments.The determined characteristics of the vacuum chamber show that it significantly affects the entire discharge.For various scenarios of the inductor operation,a comparison of experimental data and simulated currents and magnetic fields induced in the chamber was carried out.For steady-state tokamak operation,a numerical study of equilibrium plasma configurations was carried out depending on the currents in the poloidal magnetic field coils and plasma current.The vertical plasma instability was investigated.The limiting values of plasma ellipticity preventing the vertical plasma instability were numerically determined.Numerical simulations show that plasma equilibrium is supported by induced currents.It was shown numerically that magnetic configuration with‘zero of higher order’were obtained before the plasma shot,suggesting consistency between the simulation results and observations.展开更多
As a part of the new energy development trend,distributed power generation may fully utilize a variety of decentralized energy sources.Buildings close to the installation location,besides,may have a considerable impac...As a part of the new energy development trend,distributed power generation may fully utilize a variety of decentralized energy sources.Buildings close to the installation location,besides,may have a considerable impact on the wind turbines’operation.Using a combined vertical axis wind turbine with an S-shaped lift outer blade and-shaped drag inner blade,this paper investigates how a novel type of upstream wall interacts with the incident wind at various speeds,the influence region of the turbulent vortex,and performance variation.The results demonstrate that the building’s turbulence affects the wind’s horizontal and vertical direction,as well as its speed,in downstreamplaces.The wall’s effect on wind speed changing in the downstreamarea is thoroughly investigated.It turns out that while choosing an installation location,disturbing flow areas or low disturbing flow zones should be avoided to have the least impact on wind turbine performance.展开更多
A complete set of techniques for the design,installation,maintenance and use of vegetable tunnel houses in tropical island countries was developed,which achieved the goals of rain prevention,wind protection,corrosion ...A complete set of techniques for the design,installation,maintenance and use of vegetable tunnel houses in tropical island countries was developed,which achieved the goals of rain prevention,wind protection,corrosion resistance,insect and bird prevention,water-saving irrigation,and economic efficiency,significantly improving the production capacity and technical level of vegetables in Samoa.The techniques have become a key vegetable production technology promoted nationwide in Samoa,with universal promotion value for tropical island countries.展开更多
Because of the randomness of wind power and photovoltaic(PV)output of new energy bases,the problem of peak regulation capability and voltage stability of ultra-high voltage direct current(UHVDC)transmission lines,we p...Because of the randomness of wind power and photovoltaic(PV)output of new energy bases,the problem of peak regulation capability and voltage stability of ultra-high voltage direct current(UHVDC)transmission lines,we proposed an optimum allocation method of installed capacity of the solar-thermal power station based on chance constrained programming in this work.Firstly,we established the uncertainty model of wind power and PV based on the chance constrained planning theory.Then we used the K-medoids clusteringmethod to cluster the scenarios considering the actual operation scenarios throughout the year.Secondly,we established the optimal configuration model based on the objective function of the strongest transient voltage stability and the lowest overall cost of operation.Finally,by quantitative analysis of actual wind power and photovoltaic new energy base,this work verified the feasibility of the proposed method.As a result of the simulations,we found that using the optimal configuration method of solar-thermal power stations could ensure an accurate allocation of installed capacity.When the installed capacity of the solar-thermal power station is 1×106 kW,the transient voltage recovery index(TVRI)is 0.359,which has a strong voltage support capacity for the system.Based on the results of this work,the optimal configuration of the installed capacity of the solar-thermal power plant can improve peak shaving performance,transient voltage support capability,and new energy consumption while satisfying the Direct Current(DC)outgoing transmission premise.展开更多
This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet(PM)traction motor utilized in the propulsion systems for subway trains.In order to analyze accuratel...This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet(PM)traction motor utilized in the propulsion systems for subway trains.In order to analyze accurately the machine's inherent cooling capacity when the train is running,the ambient airflow and the related heat transfer coefficient(HTC)are numerically investigated considering synchronously the bogie installation structure.The machine is preliminary cooled with air ducts set on the motor shell,and the fluidic-thermal field distributions with only the shell air duct cooling are numerically calculated.During simulations,the HTC obtained in the former steps is applied to the external surface of the machine to model the inherent cooling characteristic caused by the train movement.To reduce the temperature rise and thus guarantee the motor's working reliability,an internal self-circulated air cooling system is proposed according to the machine temperature distribution.The air enclosed in the end-caps is driven by the blades mounted on both sides of the rotor core and forms two air circuits to bring the excessive power losses generated in the heating components to cool regions.The fluid flow and temperature rise distributions of the cooling system's structural parameters are further improved by the Taguchi method in order to confirm the efficacy of the internal air cooling system.展开更多
ExxonMobil pursues expansion in Huizhou On February 15^(th),in the Huizhou Daya Bay Petrochemical Zone,the heavy tower crane installation of ExxonMobil’s Huizhou Ethylene Project was completed ahead of schedule,and g...ExxonMobil pursues expansion in Huizhou On February 15^(th),in the Huizhou Daya Bay Petrochemical Zone,the heavy tower crane installation of ExxonMobil’s Huizhou Ethylene Project was completed ahead of schedule,and ground was broken on the Daya Bay Research and Development Center.展开更多
The Tokyo Electric Power Company(TEPCO)recently indicated that it expects preparations to discharge nuclearcontaminated water from the disaster-hit Fukushima Nuclear Power Plant into the sea,including installation of ...The Tokyo Electric Power Company(TEPCO)recently indicated that it expects preparations to discharge nuclearcontaminated water from the disaster-hit Fukushima Nuclear Power Plant into the sea,including installation of relevant equipment,to be completed by the end of June.Japanese media predicted the discharging operation to officially begin as early as July.展开更多
ON the morning of July 3,Zhou Hongwei,Party secretary of Huangnidun Village,visited Zhou Wenping’s home to hear the family’s suggestions regarding the village’s plan to install more street lamps and upgrade public ...ON the morning of July 3,Zhou Hongwei,Party secretary of Huangnidun Village,visited Zhou Wenping’s home to hear the family’s suggestions regarding the village’s plan to install more street lamps and upgrade public water pipelines.After the meeting,the village Party secretary immediately headed off to visit another family to hear their opinions.展开更多
基金The work described here has been supported by the TRANSIT project(funded by EU Horizon 2020 and the Europe’s Rail Joint Undertaking under grant agreement 881771).
文摘Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test bench is combined with meas-ured or predicted transfer functions.It is important,however,to allow for installation effects due to shielding by fairings or the train body.In the current work,fast-running analytical models are developed to determine these installation effects.The model for roof-mounted sources takes account of diffraction at the corner of the train body or fairing,using a barrier model.For equipment mounted under the train,the acoustic propagation from the sides of the source is based on free-field Green’s functions.The bottom surfaces are assumed to radiate initially into a cavity under the train,which is modelled with a simple diffuse field approach.The sound emitted from the gaps at the side of the cavity is then assumed to propagate to the receivers according to free-field Green’s functions.Results show good agreement with a 2.5D boundary element model and with measurements.Modelling uncertainty and parametric uncertainty are evaluated.The largest variability occurs due to the height and impedance of the ground,especially for a low receiver.This leads to standard deviations of up to 4 dB at low frequencies.For the roof-mounted sources,uncertainty over the location of the corner used in the equivalent barrier model can also lead to large standard deviations.
文摘Avivid three-dimensional rendering of a bridge appeared on the intelligent monitor and evaluation platform at Beijing Yunlu Technology Co.,Ltd.,pointing to key factors of bridge health.Real-time status,events,transportation navigation,and traffic conditions were all tracked on the screen.Numerous sensors installed on bridge track every minor dynamic change on the bridge surface and perform digital analysis.
文摘The positive figures of last year confirm the strength,resilience,and prospects of the Chinese economy.CHINA’S government work report delivered to the 2024“Two Sessions”in early March released some important statistics.The GDP surpassed RMB 126 trillion,an increase of 5.2 percent.A total of 12.44 million urban jobs were added,and the average surveyed urban unemployment rate stood at 5.2 percent by average.The consumer price index(CPI)rose by 0.2 percent.The production and sales of new-energy vehicles accounted for over 60 percent of the world’s total.Grain output hit a record high of 695 million tonnes.The installed renewable energy capacity surpassed its thermal power for the first time in Chinese history,accounting for over half of newly installed renewable energy capacity worldwide.The per capita disposable income of residents also rose by 6.1 percent nationwide.
文摘"In 2023,China's photovoltaic industry continued to maintain a rapid development momentum,with an additional installed capacity of more than 216 GW,accounting for more than half of the global total.The cumulative installed capacity is close to 610 GW,which helps the installed capacity of renewable energy surpass that of thermal power historically.In 2023,the output value of the domestic photovoltaic manufacturing industry exceeded RMB1.75 trillion,a year-on-year increase of 17.1%,and the output of the four main industrial chains of polysilicon.
文摘Translation of specialized documents in optometry presents unique challenges,requiring a deep understanding of the professional context,terminology,and adherence to specific translation styles.This paper delves into the translation theory and techniques employed in the English-to-Chinese translation of the“Optoform 80 Installation and Maintenance Manual”,serving as a case study.Emphasizing Nida’s theory of functional equivalence,the paper explores the complexities of translating professional optometry literature,focusing on key points and common issues in translating installation and maintenance manuals for optometric devices.Special attention is given to the translation of professional terminology,employing methods such as addition,omission,conversion,and repetition.The translation process aims to meet specific requirements,ensuring accuracy and coherence while aligning with Chinese language conventions.The paper also analyzes translation methods and techniques concerning terminology,prepositions,conjunctions,and handling parallel elements based on practical insights from the Optoform 80 Manual.
文摘Various industries today rely on the support of electromechanical equipment,expanding its scope of application and leading to an increase in electromechanical installation projects.However,due to the high level of expertise required and the potential risks involved,it is crucial to emphasize safety management during construction.This paper delves into the significance of construction safety management for electromechanical installation projects,identifies common problems encountered during construction,and proposes solutions.This analysis aims to provide relevant personnel with essential guidance and references for managing electromechanical installation projects safely.
文摘“Alone together”is an ever-changing“wicked problem.”In this research and practice,the author tries to combine experience design,referring to the theory of“interaction ritual chain theory,”and creatively add interactive experience to discursive works,so that the audience can think between the real and the virtual.
文摘Here are some of the achievements China made in 2023:GDP exceeded 126 trillion yuan($17.43 trillion)with a growth of 5.2 percent;12.44 million new urban jobs were created;average surveyed unemployment rate in urban areas was 5.2 percent;consumer price index increased by 0.2 percent;new energy vehicle production and sales accounted for more than 60 percent of the global share;grain output reached a record high of 695 billion kg;installed renewable energy capacity surpassed thermal power capacity for the first time in history,and China accounted for over half of newly installed renewable energy capacity worldwide;per-capita disposable income of residents increased by 6.1 percent…
文摘Digital media art is an emerging art form that combines digital technology and media art.It has huge potential to bring innovation to urban public spaces and provide them with vibrant artistic experiences.This article analyzes the design significance and value of digital media art in urban public space,its various forms of application in urban public space design,and the innovative ideas and paths that digital media art can take in urban public space to guide the future.The application and innovative methods of digital media art in urban public space design provide certain theoretical and practical references for urban planners and designers.
文摘To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction technology.These aspects include the lightning protection classification of buildings,air terminals,down conductors,grounding devices,division of lightning protection zones,and lightning electromagnetic pulse shielding.Through the introduction of this article,readers can gain a comprehensive understanding of the application and value of lightning protection grounding construction technology in building electrical installation projects.
基金supported by the National Natural Science Foundation of China-Shandong Joint Fund(Grant No.U2006226).
文摘Compliant vertical access risers(CVAR)have broad application prospects in deep-water oil and gas transportation.However,the mechanical behaviors of the CVAR with a variable length during installation remains unclear.To address this issue,based on the flexible segment method,a model of CVAR with a variable length during installation is established in this study,which is verified by the comparison with commercial software.Then,the mechanical behaviors of CVAR during installation are investigated.The results reveal that the CVAR configuration is significantly affected by the buoyancy blocks.The streamwise displacement of CVAR increases with the increase of current velocity.When the BOP weight is insuffcient,obvious upbending is observed in the lower region and transition region,leading to local compression.When the platform moves in the opposite direction to the current,the maximum stress is larger than that of the scenario when the platform moves in the same direction as the current.
基金financially supported by the National Natural Science Foundation of China (Grant Nos.52371301,51879044 and 51808325)the Shandong Natural Fund (Grant No.ZR2020QE258)。
文摘Suction caissons are widely used for anchoring floating platform and offshore wind turbines.Penetration of the suction caisson into the desired position under the combination of its self-weight and applied suction resulted from pumping out the encased water is integral to practical engineering.Model tests were carried out to investigate the suctionassisted installation of suction caissons in clay under various undrained shear strengths.It was found that there exists a critical penetration depth value.When the penetration depth is smaller than the critical value,the soil plug undrained shear strength is higher than intact clay(i.e.,clay prior to installation).However,when the penetration depth is greater than the critical penetration depth,the undrained shear strength of soil plug is lower than intact clay.The critical value decreases with the increasing consolidation time and undrained shear strength of clay.During suction-assisted installation,cracks occur around suction caissons.The installation way has little effect on the crack formation.The influence range(i.e.,the maximum distance between the crack and the suction caisson edge)was found to increase with the increasing friction coefficient of interface between the suction caisson wall and soil and decreases with the increasing soil undrained shear strength.In addition,the drained condition of the clay during installation is dominated by the caisson aspect ratio,the undrained shear strength and the friction coefficient between the caisson wall and clay.Equations to estimate the penetration resistance and the required suction to install the suction caisson are summarized.
基金financial support of the Ministry of Education and Science of the Russian Federation as part of the program of the Mathematical Center for Fundamental and Applied Mathematics(No.075-15-2019-162)partly RFBR(No.20-07-00391)。
文摘This paper presents the results of numerical simulation of plasma equilibrium and stability in the MEPHIST-0 tokamak with SIEMNED software and comparison of simulation results with experiments.The determined characteristics of the vacuum chamber show that it significantly affects the entire discharge.For various scenarios of the inductor operation,a comparison of experimental data and simulated currents and magnetic fields induced in the chamber was carried out.For steady-state tokamak operation,a numerical study of equilibrium plasma configurations was carried out depending on the currents in the poloidal magnetic field coils and plasma current.The vertical plasma instability was investigated.The limiting values of plasma ellipticity preventing the vertical plasma instability were numerically determined.Numerical simulations show that plasma equilibrium is supported by induced currents.It was shown numerically that magnetic configuration with‘zero of higher order’were obtained before the plasma shot,suggesting consistency between the simulation results and observations.
基金supported in part by the Provincial,Municipal and Autonomous Region Science and Technology Project Funds of China 2021GG0336 and 2016030331。
文摘As a part of the new energy development trend,distributed power generation may fully utilize a variety of decentralized energy sources.Buildings close to the installation location,besides,may have a considerable impact on the wind turbines’operation.Using a combined vertical axis wind turbine with an S-shaped lift outer blade and-shaped drag inner blade,this paper investigates how a novel type of upstream wall interacts with the incident wind at various speeds,the influence region of the turbulent vortex,and performance variation.The results demonstrate that the building’s turbulence affects the wind’s horizontal and vertical direction,as well as its speed,in downstreamplaces.The wall’s effect on wind speed changing in the downstreamarea is thoroughly investigated.It turns out that while choosing an installation location,disturbing flow areas or low disturbing flow zones should be avoided to have the least impact on wind turbine performance.
文摘A complete set of techniques for the design,installation,maintenance and use of vegetable tunnel houses in tropical island countries was developed,which achieved the goals of rain prevention,wind protection,corrosion resistance,insect and bird prevention,water-saving irrigation,and economic efficiency,significantly improving the production capacity and technical level of vegetables in Samoa.The techniques have become a key vegetable production technology promoted nationwide in Samoa,with universal promotion value for tropical island countries.
基金funded by Major Science and Technology Projects in Gansu Province(19ZD2GA003).
文摘Because of the randomness of wind power and photovoltaic(PV)output of new energy bases,the problem of peak regulation capability and voltage stability of ultra-high voltage direct current(UHVDC)transmission lines,we proposed an optimum allocation method of installed capacity of the solar-thermal power station based on chance constrained programming in this work.Firstly,we established the uncertainty model of wind power and PV based on the chance constrained planning theory.Then we used the K-medoids clusteringmethod to cluster the scenarios considering the actual operation scenarios throughout the year.Secondly,we established the optimal configuration model based on the objective function of the strongest transient voltage stability and the lowest overall cost of operation.Finally,by quantitative analysis of actual wind power and photovoltaic new energy base,this work verified the feasibility of the proposed method.As a result of the simulations,we found that using the optimal configuration method of solar-thermal power stations could ensure an accurate allocation of installed capacity.When the installed capacity of the solar-thermal power station is 1×106 kW,the transient voltage recovery index(TVRI)is 0.359,which has a strong voltage support capacity for the system.Based on the results of this work,the optimal configuration of the installed capacity of the solar-thermal power plant can improve peak shaving performance,transient voltage support capability,and new energy consumption while satisfying the Direct Current(DC)outgoing transmission premise.
基金supported by the National Natural Science Foundation of China under Grant 52107007the China Scholarship Council under Grant 202008120084the“Chunhui Plan”Collaborative Research Project of Chinese Ministry of Education under Grant HZKY20220604。
文摘This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet(PM)traction motor utilized in the propulsion systems for subway trains.In order to analyze accurately the machine's inherent cooling capacity when the train is running,the ambient airflow and the related heat transfer coefficient(HTC)are numerically investigated considering synchronously the bogie installation structure.The machine is preliminary cooled with air ducts set on the motor shell,and the fluidic-thermal field distributions with only the shell air duct cooling are numerically calculated.During simulations,the HTC obtained in the former steps is applied to the external surface of the machine to model the inherent cooling characteristic caused by the train movement.To reduce the temperature rise and thus guarantee the motor's working reliability,an internal self-circulated air cooling system is proposed according to the machine temperature distribution.The air enclosed in the end-caps is driven by the blades mounted on both sides of the rotor core and forms two air circuits to bring the excessive power losses generated in the heating components to cool regions.The fluid flow and temperature rise distributions of the cooling system's structural parameters are further improved by the Taguchi method in order to confirm the efficacy of the internal air cooling system.
文摘ExxonMobil pursues expansion in Huizhou On February 15^(th),in the Huizhou Daya Bay Petrochemical Zone,the heavy tower crane installation of ExxonMobil’s Huizhou Ethylene Project was completed ahead of schedule,and ground was broken on the Daya Bay Research and Development Center.
文摘The Tokyo Electric Power Company(TEPCO)recently indicated that it expects preparations to discharge nuclearcontaminated water from the disaster-hit Fukushima Nuclear Power Plant into the sea,including installation of relevant equipment,to be completed by the end of June.Japanese media predicted the discharging operation to officially begin as early as July.
文摘ON the morning of July 3,Zhou Hongwei,Party secretary of Huangnidun Village,visited Zhou Wenping’s home to hear the family’s suggestions regarding the village’s plan to install more street lamps and upgrade public water pipelines.After the meeting,the village Party secretary immediately headed off to visit another family to hear their opinions.