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2024 Adult Compendium of Physical Activities:A third update of the energy costs of human activities 被引量:5
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作者 Stephen D.Herrmann Erik A.Willis +10 位作者 Barbara E.Ainsworth Tiago V.Barreira Mary Hastert Chelsea L.Kracht John M.Schuna Jr. Zhenghui Cai Minghui Quan Catrine Tudor-Locke Melicia C.Whitt-Glover David R. Jacobs Jr. 《Journal of Sport and Health Science》 SCIE CSCD 2024年第1期6-12,共7页
Background:The Compendium of Physical Activities was published in 1993 to improve the comparability of energy expenditure values assigned to self-reported physical activity(PA)across studies.The original version was u... Background:The Compendium of Physical Activities was published in 1993 to improve the comparability of energy expenditure values assigned to self-reported physical activity(PA)across studies.The original version was updated in 2000,and again in 2011,and has been widely used to support PA research,practice,and public health guidelines.Methods:This 2024 update was tailored for adults 19-59 years of age by removing data from those≥60 years.Using a systematic review and supplementary searches,we identified new activities and their associated measured metabolic equivalent(MET)values(using indirect calorimetry)published since 2011.We replaced estimated METs with measured values when possible.Results:We screened 32,173 abstracts and 1507 full-text papers and extracted 2356 PA energy expenditure values from 701 papers.We added303 new PAs and adjusted 176 existing MET values and descriptions to reflect the addition of new data and removal of METs for older adults.We added a Major Heading(Video Games).The 2024 Adult Compendium includes 1114 PAs(912 with measured and 202 with estimated values)across 22 Major Headings.Conclusion:This comprehensive update and refinement led to the creation of The 2024 Adult Compendium,which has utility across research,public health,education,and healthcare domains,as well as in the development of consumer health technologies.The new website with the complete lists of PAs and supporting resources is available at https://pacompendium.com. 展开更多
关键词 ADULTS energy expenditure EXERCISE MET Physical Activities
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Older Adult Compendium of Physical Activities:Energy costs of human activities in adults aged 60 and older 被引量:3
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作者 Erik A.Willis Stephen D.Herrmann +8 位作者 Mary Hastert Chelsea L.Kracht Tiago V.Barreira John M.Schuna Jr. Zhenghua Cai Minghui Quan Scott A.Conger Wendy J.Brown Barbara E.Ainsworth 《Journal of Sport and Health Science》 SCIE CSCD 2024年第1期13-17,F0003,共6页
Purpose:To describe the development of a Compendium for estimating the energy costs of activities in adults>60 years(OA Compendium).Methods:Physical activities(PAs)and their metabolic equivalent of task(MET)values ... Purpose:To describe the development of a Compendium for estimating the energy costs of activities in adults>60 years(OA Compendium).Methods:Physical activities(PAs)and their metabolic equivalent of task(MET)values were obtained from a systematic search of studies published in 4 sport and exercise databases(PubMed,Embase,SPORTDiscus(EBSCOhost),and Scopus)and a review of articles included in the 2011 Adult Compendium that measured PA in older adults.MET values were computed as the oxygen cost(VO_(2),mL/kg/min)during PA divided by 2.7 m L/kg/min(MET_(60+))to account for the lower resting metabolic rate in older adults.Results:We identified 68 articles and extracted energy expenditure data on 427 PAs.From these,we derived 99 unique Specific Activity codes with corresponding MET_(60+)values for older adults.We developed a website to present the OA Compendium MET_(60+)values:https://pacompendium.com.Conclusion:The OA Compendium uses data collected from adults>60 years for more accurate estimation of the energy cost of PAs in older adults.It is an accessible resource that will allow researchers,educators,and practitioners to find MET_(60+)values for older adults for use in PA research and practice. 展开更多
关键词 energy expenditure EXERCISE MET Older adults
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Oxygen functionalization-assisted anionic exchange toward unique construction of flower-like transition metal chalcogenide embedded carbon fabric for ultra-long life flexible energy storage and conversion 被引量:1
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作者 Roshan M.Bhattarai Kisan Chhetri +5 位作者 Nghia Le Debendra Acharya Shirjana Saud Mai Cao Hoang Phuong Lan Nguyen Sang Jae Kim Young Sun Mok 《Carbon Energy》 SCIE EI CAS CSCD 2024年第1期72-93,共22页
The metal-organic framework(MOF)derived Ni–Co–C–N composite alloys(NiCCZ)were“embedded”inside the carbon cloth(CC)strands as opposed to the popular idea of growing them upward to realize ultrastable energy storag... The metal-organic framework(MOF)derived Ni–Co–C–N composite alloys(NiCCZ)were“embedded”inside the carbon cloth(CC)strands as opposed to the popular idea of growing them upward to realize ultrastable energy storage and conversion application.The NiCCZ was then oxygen functionalized,facilitating the next step of stoichiometric sulfur anion diffusion during hydrothermal sulfurization,generating a flower-like metal hydroxysulfide structure(NiCCZOS)with strong partial implantation inside CC.Thus obtained NiCCZOS shows an excellent capacity when tested as a supercapacitor electrode in a three-electrode configuration.Moreover,when paired with the biomass-derived nitrogen-rich activated carbon,the asymmetric supercapacitor device shows almost 100%capacity retention even after 45,000 charge–discharge cycles with remarkable energy density(59.4 Wh kg^(-1)/263.8μWh cm^(–2))owing to a uniquely designed cathode.Furthermore,the same electrode performed as an excellent bifunctional water-splitting electrocatalyst with an overpotential of 271 mV for oxygen evolution reaction(OER)and 168.4 mV for hydrogen evolution reaction(HER)at 10 mA cm−2 current density along with 30 h of unhinged chronopotentiometric stability performance for both HER and OER.Hence,a unique metal chalcogenide composite electrode/substrate configuration has been proposed as a highly stable electrode material for flexible energy storage and conversion applications. 展开更多
关键词 carbon cloth energy conversion energy storage FLEXIBLE metal embedding ultra-stable
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Dynamics and vibration reduction performance of asymmetric tristable nonlinear energy sink 被引量:2
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作者 Hongyan CHEN Youcheng ZENG +2 位作者 Hu DING Siukai LAI Liqun CHEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第3期389-406,共18页
With its complex nonlinear dynamic behavior,the tristable system has shown excellent performance in areas such as energy harvesting and vibration suppression,and has attracted a lot of attention.In this paper,an asymm... With its complex nonlinear dynamic behavior,the tristable system has shown excellent performance in areas such as energy harvesting and vibration suppression,and has attracted a lot of attention.In this paper,an asymmetric tristable design is proposed to improve the vibration suppression efficiency of nonlinear energy sinks(NESs)for the first time.The proposed asymmetric tristable NES(ATNES)is composed of a pair of oblique springs and a vertical spring.Then,the three stable states,symmetric and asymmetric,can be achieved by the adjustment of the distance and stiffness asymmetry of the oblique springs.The governing equations of a linear oscillator(LO)coupled with the ATNES are derived.The approximate analytical solution to the coupled system is obtained by the harmonic balance method(HBM)and verified numerically.The vibration suppression efficiency of three types of ATNES is compared.The results show that the asymmetric design can improve the efficiency of vibration reduction through comparing the chaotic motion of the NES oscillator between asymmetric steady states.In addition,compared with the symmetrical tristable NES(TNES),the ATNES can effectively control smaller structural vibrations.In other words,the ATNES can effectively solve the threshold problem of TNES failure to weak excitation.Therefore,this paper reveals the vibration reduction mechanism of the ATNES,and provides a pathway to expand the effective excitation amplitude range of the NES. 展开更多
关键词 ASYMMETRIC nonlinear energy sink(NES) tristable vibration control po-tential barrier
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Thermo-hydro-mechanical (THM) coupled simulation of the land subsidence due to aquifer thermal energy storage (ATES) system in soft soils 被引量:1
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作者 Yang Wang Fengshou Zhang Fang Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期1952-1966,共15页
Aquifer thermal energy storage(ATES)system has received attention for heating or cooling buildings.However,it is well known that land subsidence becomes a major environmental concern for ATES projects.Yet,the effect o... Aquifer thermal energy storage(ATES)system has received attention for heating or cooling buildings.However,it is well known that land subsidence becomes a major environmental concern for ATES projects.Yet,the effect of temperature on land subsidence has received practically no attention in the past.This paper presents a thermo-hydro-mechanical(THM)coupled numerical study on an ATES system in Shanghai,China.Four water wells were installed for seasonal heating and cooling of an agriculture greenhouse.The target aquifer at a depth of 74e104.5 m consisted of alternating layers of sand and silty sand and was covered with clay.Groundwater level,temperature,and land subsidence data from 2015 to 2017 were collected using field monitoring instruments.Constrained by data,we constructed a field scale three-dimensional(3D)model using TOUGH(Transport of Unsaturated Groundwater and Heat)and FLAC3D(Fast Lagrangian Analysis of Continua)equipped with a thermo-elastoplastic constitutive model.The effectiveness of the numerical model was validated by field data.The model was used to reproduce groundwater flow,heat transfer,and mechanical responses in porous media over three years and capture the thermo-and pressure-induced land subsidence.The results show that the maximum thermoinduced land subsidence accounts for about 60%of the total subsidence.The thermo-induced subsidence is slightly greater in winter than that in summer,and more pronounced near the cold well area than the hot well area.This study provides some valuable guidelines for controlling land subsidence caused by ATES systems installed in soft soils. 展开更多
关键词 Aquifer thermal energy storage(ATES) Land subsidence TOUGH-FLAC3D Thermo-elastoplastic constitutive model
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Review on laser directed energy deposited aluminum alloys 被引量:1
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作者 Tian-Shu Liu Peng Chen +7 位作者 Feng Qiu Hong-Yu Yang Nicholas Tan Yew Jin Youxiang Chew Di Wang Ruidi Li Qi-Chuan Jiang Chaolin Tan 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第2期84-131,共48页
Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstrea... Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstream AM technique,laser-directed energy deposition(LDED)shows good scalability to meet the requirements for large-format component manufacturing and repair.However,LDED Al alloys are highly challenging due to their inherent poor printability(e.g.low laser absorption,high oxidation sensitivity and cracking tendency).To further promote the development of LDED high-performance Al alloys,this review offers a deep understanding of the challenges and strategies to improve printability in LDED Al alloys.The porosity,cracking,distortion,inclusions,element evaporation and resultant inferior mechanical properties(worse than laser powder bed fusion)are the key challenges in LDED Al alloys.Processing parameter optimizations,in-situ alloy design,reinforcing particle addition and field assistance are the efficient approaches to improving the printability and performance of LDED Al alloys.The underlying correlations between processes,alloy innovation,characteristic microstructures,and achievable performances in LDED Al alloys are discussed.The benchmark mechanical properties and primary strengthening mechanism of LDED Al alloys are summarized.This review aims to provide a critical and in-depth evaluation of current progress in LDED Al alloys.Future opportunities and perspectives in LDED high-performance Al alloys are also outlined. 展开更多
关键词 additive manufacturing laser directed energy deposition(LDED) aluminum alloys PRINTABILITY aluminum matrix composite auxiliary fields mechanical properties
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Mechanical behavior of rock under uniaxial tension:Insights from energy storage and dissipation
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作者 Guanshuang Tan Chunde Ma +3 位作者 Junjie Zhang Wenyuan Yang Guiyin Zhang Zihao Kang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2466-2481,共16页
Many rock engineering projects show that the growth of tensile cracks is often an important cause of engineering disasters,and the mechanical behavior of rocks is essentially the transmission,storage,dissipation and r... Many rock engineering projects show that the growth of tensile cracks is often an important cause of engineering disasters,and the mechanical behavior of rocks is essentially the transmission,storage,dissipation and release of energy.To investigate the tensile behavior of rock from the perspective of energy,uniaxial tension tests(UTTs)and uniaxial compression tests(UCTs)were carried out on three typical rocks(granite,sandstone and marble).Different unloading points were set before the peak stress to separate elastic energy and dissipated energy.The input energy density ut,elastic energy density ue,and dissipated energy density ud at each unloading point were calculated by integrating stress-strain curves.The results show that there is a strong linear relationship between the three energy parameters and the square of the unloading stress in UCT,but this linear relationship is weaker in UTT.The ue and ud increase linearly with the increase in ut in UCT and UTT.Based on the phenomenon that ue and ud increase linearly with ut,the applicability of Wp et index in UTT was proved and the relative energy storage capacity and absolute energy distribution characteristics of three rocks in UCT and UTT were evaluated.The tensile behavior of marble and sandstone in UTT can be divided into two stages vaguely according to the energy distribution,but granite is not the case.In addition,based on dissipated energy,the damage evolution of three types of rocks in UCT and UTT was discussed.This study provides some new insights for understanding the tensile behavior of rock. 展开更多
关键词 Uniaxial tension energy density Mechanical behavior energy storage coefficient energy dissipation coefficient
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A Distributionally Robust Optimization Scheduling Model for Regional Integrated Energy Systems Considering Hot Dry Rock Co-Generation
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作者 Hao Qi Mohamed Sharaf +2 位作者 Andres Annuk Adrian Ilinca Mohamed A.Mohamed 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1387-1404,共18页
Hot dry rock(HDR)is rich in reserve,widely distributed,green,low-carbon,and has broad development potential and prospects.In this paper,a distributionally robust optimization(DRO)scheduling model for a regionally inte... Hot dry rock(HDR)is rich in reserve,widely distributed,green,low-carbon,and has broad development potential and prospects.In this paper,a distributionally robust optimization(DRO)scheduling model for a regionally integrated energy system(RIES)considering HDR co-generation is proposed.First,the HDR-enhanced geothermal system(HDR-EGS)is introduced into the RIES.HDR-EGS realizes the thermoelectric decoupling of combined heat and power(CHP)through coordinated operation with the regional power grid and the regional heat grid,which enhances the system wind power(WP)feed-in space.Secondly,peak-hour loads are shifted using price demand response guidance in the context of time-of-day pricing.Finally,the optimization objective is established to minimize the total cost in the RIES scheduling cycle and construct a DRO scheduling model for RIES with HDR-EGS.By simulating a real small-scale RIES,the results show that HDR-EGS can effectively promote WP consumption and reduce the operating cost of the system. 展开更多
关键词 energy harvesting integrated energy systems optimum scheduling time-of-use pricing demand response geothermal energy
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Solar and wind energy potential assessment for Razavi Khorasan Province in Iran
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作者 HOSSEINI Amirpouya RAMEZANI Faeze MIRHOSSEINI Mojtaba 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2027-2038,共12页
This study aims to evaluate the solar and wind energy potential across Razavi Khorasan Province,Iran,with a specific focus on the Khaf region.A preliminary assessment of mean solar radiation,mean wind speeds,and Weibu... This study aims to evaluate the solar and wind energy potential across Razavi Khorasan Province,Iran,with a specific focus on the Khaf region.A preliminary assessment of mean solar radiation,mean wind speeds,and Weibull distribution parameters was conducted for different towns and zones within the province.The findings showed that Khaf has favorable characteristics for further analysis.The solar and wind energy metrics examined include global horizontal irradiance,clearness index,wind rose patterns,and turbulence intensity.At a height of 40 m,Khaf’s wind power density reached 1650 W/m^(2),indicating exceptional wind energy generation potential.Additionally,Khaf received an average annual solar radiation of 2046 kW·h/m^(2),representing significant solar energy potential.Harnessing these substantial renewable resources in Khaf could allow Razavi Khorasan Province to reduce reliance on fossil fuels,improve energy sustainability,and mitigate climate change impacts.This research contributes an in-depth assessment of Razavi Khorasan's solar and wind energy potential,particularly for the promising Khaf region.Further work may examine optimal sites for renewable energy projects and grid integration strategies to leverage these resources. 展开更多
关键词 solar energy wind energy Razavi Khorasan RADIATION Weibull distribution
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Recent advances in graphene-based phase change composites for thermal energy storage and management
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作者 Qiang Zhu Pin Jin Ong +4 位作者 Si Hui Angela Goh Reuben J.Yeo Suxi Wang Zhiyuan Liu Xian Jun Loh 《Nano Materials Science》 EI CAS CSCD 2024年第2期115-138,共24页
Energy storage and conservation are receiving increased attention due to rising global energy demands.Therefore,the development of energy storage materials is crucial.Thermal energy storage(TES)systems based on phase ... Energy storage and conservation are receiving increased attention due to rising global energy demands.Therefore,the development of energy storage materials is crucial.Thermal energy storage(TES)systems based on phase change materials(PCMs)have increased in prominence over the past two decades,not only because of their outstanding heat storage capacities but also their superior thermal energy regulation capability.However,issues such as leakage and low thermal conductivity limit their applicability in a variety of settings.Carbon-based materials such as graphene and its derivatives can be utilized to surmount these obstacles.This study examines the recent advancements in graphene-based phase change composites(PCCs),where graphene-based nanostructures such as graphene,graphene oxide(GO),functionalized graphene/GO,and graphene aerogel(GA)are incorporated into PCMs to substantially enhance their shape stability and thermal conductivity that could be translated to better storage capacity,durability,and temperature response,thus boosting their attractiveness for TES systems.In addition,the applications of these graphene-based PCCs in various TES disciplines,such as energy conservation in buildings,solar utilization,and battery thermal management,are discussed and summarized. 展开更多
关键词 Phase change material NANOCOMPOSITES Solar energy Sustainable energy Thermo-regulation
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Investigating and predicting the role of photovoltaic, wind, and hydrogen energies in sustainable global energy evolution
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作者 Mahmood Swadi Dheyaa Jasim Kadhim +3 位作者 Mohamed Salem Firas Mohammed Tuaimah Ammar SabriMajeed Ali Jawad Alrubaie 《Global Energy Interconnection》 EI CSCD 2024年第4期429-445,共17页
The global shift toward next-generation energy systems is propelled by the urgent need to combat climate change and the dwindling supply of fossil fuels.This review explores the intricate challenges and opportunities ... The global shift toward next-generation energy systems is propelled by the urgent need to combat climate change and the dwindling supply of fossil fuels.This review explores the intricate challenges and opportunities for transitioning to sustainable renewable energy sources such as solar,wind,and hydrogen.This transition economically challenges traditional energy sectors while fostering new industries,promoting job growth,and sustainable economic development.The transition to renewable energy demands social equity,ensuring universal access to affordable energy,and considering community impact.The environmental benefits include a significant reduction in greenhouse gas emissions and a lesser ecological footprint.This study highlights the rapid growth of the global wind power market,which is projected to increase from$112.23 billion in 2022 to$278.43 billion by 2030,with a compound annual growth rate of 13.67%.In addition,the demand for hydrogen is expected to increase,significantly impacting the market with potential cost reductions and making it a critical renewable energy source owing to its affordability and zero emissions.By 2028,renewables are predicted to account for 42%of global electricity generation,with significant contributions from wind and solar photovoltaic(PV)technology,particularly in China,the European Union,the United States,and India.These developments signify a global commitment to diversifying energy sources,reducing emissions,and moving toward cleaner and more sustainable energy solutions.This review offers stakeholders the insights required to smoothly transition to sustainable energy,setting the stage for a resilient future. 展开更多
关键词 Next energy Renewable energy SUSTAINABILITY Environmental benefits Economic opportunities
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Revealing the correlation between adsorption energy and activation energy to predict the catalytic activity of metal oxides for HMX using DFT
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作者 Xiurong Yang Chi Zhang +6 位作者 Wujing Jin Zhaoqi Guo Hongxu Gao Shiyao Niu Fengqi Zhao Bo Liu Haixia Ma 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期262-270,共9页
Traditional selection of combustion catalysis is time-consuming and labor-intensive.Theoretical calculation is expected to resolve this problem.The adsorption energy of HMX and O atoms on 13 metal oxides was calculate... Traditional selection of combustion catalysis is time-consuming and labor-intensive.Theoretical calculation is expected to resolve this problem.The adsorption energy of HMX and O atoms on 13 metal oxides was calculated using DMol3,since HMX and O are key substances in decomposition process.And the relationship between the adsorption energy of HMX,O on metal oxides(TiO_(2),Al_(2)O_(3),PbO,CuO,Fe_(2)O_(3),Co_(3)O_(4),Bi_(2)O_(3),NiO)and experimental T30 values(time required for the decomposition depth of HMX to reach 30%)was depicted as volcano plot.Thus,the T30 values of other metal oxides was predicted based on their adsorption energy on volcano plot and validated by previous experimental data.Further,the adsorption energy of HMX on ZrO_(2)and MnO_(2)was predicted based on the linear relationship between surface energy and adsorption energy,and T30 values were estimated based on volcano plot.The apparent activation energy data of HMX/MgO,HMX/SnO_(2),HMX/ZrO_(2),and HMX/MnO_(2)obtained from DSC experiments are basically consistent with our predicted T30 values,indicating that it is feasible to predict the catalytic activity based on the adsorption calculation,and it is expected that these simple structural properties can predict adsorption energy to reduce the large quantities of computation and experiment cost. 展开更多
关键词 Density functional theory HMX Metal oxides Adsorption energy Activation energy
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A viscoelastic nonlinear energy sink with an electromagnetic energy harvester:Narrow-band random response
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作者 廖志晶 孙亚辉 刘洋 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期147-156,共10页
Nonlinear energy sink is a passive energy absorption device that surpasses linear dampers, and has gained significant attention in various fields of vibration suppression. This is owing to its capacity to offer high v... Nonlinear energy sink is a passive energy absorption device that surpasses linear dampers, and has gained significant attention in various fields of vibration suppression. This is owing to its capacity to offer high vibration attenuation and robustness across a wide frequency spectrum. Energy harvester is a device employed to convert kinetic energy into usable electric energy. In this paper, we propose an electromagnetic energy harvester enhanced viscoelastic nonlinear energy sink(VNES) to achieve passive vibration suppression and energy harvesting simultaneously. A critical departure from prior studies is the investigation of the stochastic P-bifurcation of the electromechanically coupled VNES system under narrowband random excitation. Initially, approximate analytical solutions are derived using a combination of a multiple-scale method and a perturbation approach. The substantial agreement between theoretical analysis solutions and numerical solutions obtained from Monte Carlo simulation underscores the method's high degree of validity. Furthermore, the effects of system parameters on system responses are carefully examined. Additionally, we demonstrate that stochastic P-bifurcation can be induced by system parameters, which is further verified by the steady-state density functions of displacement. Lastly,we analyze the impacts of various parameters on the mean square current and the mean output power, which are crucial for selecting suitable parameters to enhance the energy harvesting performance. 展开更多
关键词 nonlinear energy sink fractional-order damping multiple-scale method energy harvester
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Advances in Triboelectric Nanogenerators for Blue Energy Harvesting and Marine Environmental Monitoring
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作者 Yang Jiang Xi Liang +1 位作者 Tao Jiang Zhong Lin Wang 《Engineering》 SCIE EI CAS CSCD 2024年第2期204-224,共21页
Blue energy,which includes rainfall,tidal current,wave,and water-flow energy,is a promising renewable resource,although its exploitation is limited by current technologies and thus remains low.This form of energy is m... Blue energy,which includes rainfall,tidal current,wave,and water-flow energy,is a promising renewable resource,although its exploitation is limited by current technologies and thus remains low.This form of energy is mainly harvested by electromagnetic generators(EMGs),which generate electricity via Lorenz force-driven electron flows.Triboelectric nano genera tors(TENGs)and TENG networks exhibit superiority over EMGs in low-frequency and high-entropy energy harvesting as a new approach for blue energy harvesting.A TENG produces electrical outputs by adopting the mechanism of Maxwell’s displacement current.To date,a series of research efforts have been made to optimize the structure and performance of TENGs for effective blue energy harvesting and marine environmental applications.Despite the great progress that has been achieved in the use of TENGs in this context so far,continuous exploration is required in energy conversion,device durability,power management,and environmental applications.This review reports on advances in TENGs for blue energy harvesting and marine environmental monitoring.It introduces the theoretical foundations of TENGs and discusses advanced TENG prototypes for blue energy harvesting,including TENG structures that function in freestanding and contact-separation modes.Performance enhancement strategies for TENGs intended for blue energy harvesting are also summarized.Finally,marine environmental applications of TENGs based on blue energy harvesting are discussed. 展开更多
关键词 Triboelectric nanogenerator TENG networks Blue energy energy harvesting Ocean sensors
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Reinforcement Learning-Based Energy Management for Hybrid Power Systems:State-of-the-Art Survey,Review,and Perspectives
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作者 Xiaolin Tang Jiaxin Chen +4 位作者 Yechen Qin Teng Liu Kai Yang Amir Khajepour Shen Li 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期1-25,共25页
The new energy vehicle plays a crucial role in green transportation,and the energy management strategy of hybrid power systems is essential for ensuring energy-efficient driving.This paper presents a state-of-the-art ... The new energy vehicle plays a crucial role in green transportation,and the energy management strategy of hybrid power systems is essential for ensuring energy-efficient driving.This paper presents a state-of-the-art survey and review of reinforcement learning-based energy management strategies for hybrid power systems.Additionally,it envisions the outlook for autonomous intelligent hybrid electric vehicles,with reinforcement learning as the foundational technology.First of all,to provide a macro view of historical development,the brief history of deep learning,reinforcement learning,and deep reinforcement learning is presented in the form of a timeline.Then,the comprehensive survey and review are conducted by collecting papers from mainstream academic databases.Enumerating most of the contributions based on three main directions—algorithm innovation,powertrain innovation,and environment innovation—provides an objective review of the research status.Finally,to advance the application of reinforcement learning in autonomous intelligent hybrid electric vehicles,future research plans positioned as“Alpha HEV”are envisioned,integrating Autopilot and energy-saving control. 展开更多
关键词 New energy vehicle Hybrid power system Reinforcement learning energy management strategy
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Energy dissipation mechanism and ballistic characteristic optimization in foam sandwich panels against spherical projectile impact
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作者 Jianqiang Deng Tao Liu +4 位作者 Liming Chen Xin Pan Jingzhe Wang Shaowei Zhu Weiguo Li 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期108-122,共15页
This study systematically examines the energy dissipation mechanisms and ballistic characteristics of foam sandwich panels(FSP)under high-velocity impact using the explicit non-linear finite element method.Based on th... This study systematically examines the energy dissipation mechanisms and ballistic characteristics of foam sandwich panels(FSP)under high-velocity impact using the explicit non-linear finite element method.Based on the geometric topology of the FSP system,three FSP configurations with the same areal density are derived,namely multi-layer,gradient core and asymmetric face sheet,and three key structural parameters are identified:core thickness(t_(c)),face sheet thickness(t_(f))and overlap face/core number(n_(o)).The ballistic performance of the FSP system is comprehensively evaluated in terms of the ballistic limit velocity(BLV),deformation modes,energy dissipation mechanism,and specific penetration energy(SPE).The results show that the FSP system exhibits a significant configuration dependence,whose ballistic performance ranking is:asymmetric face sheet>gradient core>multi-layer.The mass distribution of the top and bottom face sheets plays a critical role in the ballistic resistance of the FSP system.Both BLV and SPE increase with tf,while the raising tcor noleads to an increase in BLV but a decrease in SPE.Further,a face-core synchronous enhancement mechanism is discovered by the energy dissipation analysis,based on which the ballistic optimization procedure is also conducted and a design chart is established.This study shed light on the anti-penetration mechanism of the FSP system and might provide a theoretical basis for its engineering application. 展开更多
关键词 Sandwich panel Numerical simulation Ballistic resistance Specific penetration energy energy analysis
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Regenerative Braking Energy Recovery System ofMetro Train Based on Dual-Mode PowerManagement
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作者 Feng Zhao Xiaotong Zhu +1 位作者 Xiaoqiang Chen Ying Wang 《Energy Engineering》 EI 2024年第9期2585-2601,共17页
In order to fully utilize the regenerative braking energy of metro trains and stabilize the metro DC traction busbar voltage,a hybrid regenerative braking energy recovery system with a dual-mode power management strat... In order to fully utilize the regenerative braking energy of metro trains and stabilize the metro DC traction busbar voltage,a hybrid regenerative braking energy recovery system with a dual-mode power management strategy is proposed.Firstly,the construction of the hybrid regenerative braking energy recovery system is explained.Then,based on the power demand of low-voltage load in metro stations,a dual-mode power management strategy is proposed to allocate the reference power of each system according to the different working conditions,and the control methods of each system are set.Finally,the correctness and effectiveness of the dual-mode strategy are verified through simulation,and the proposed braking energy utilization scheme is compared with other singleform utilization schemes.The results illustrate that the hybrid system with the dual-mode strategy can effectively recycle the regenerative braking energy of metro train and inhibit the busbar voltage fluctuation;the proposed braking energy utilization scheme has certain advantages on energy recovery and DC bus voltage stabilization compared with other single-form schemes;the proposed power management strategy can correctly allocate the reference power of each system with a lower construction cost. 展开更多
关键词 Metro train regenerative braking energy energy feed-back system energy storage system power management
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Renewable Energy: Prospects and Challenges in Bangladesh
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作者 Abul Fattah Mohammad Masum Rabbani Md. Masudur Rahman Rahat +1 位作者 Ahsan Habib Md. Nazrul Islam 《Energy and Power Engineering》 2024年第2期43-78,共36页
Among expert scientists and politicians, there is increasing agreement that it is absolutely necessary to reduce the emission of greenhouse gas (GHG) to lessen the severity of climate change. Although little, renewabl... Among expert scientists and politicians, there is increasing agreement that it is absolutely necessary to reduce the emission of greenhouse gas (GHG) to lessen the severity of climate change. Although little, renewable energy sources currently reduce GHG that are being emitted from the energy industries. According to the majority of long-term energy estimates, renewable energy will be a substantial addition to the supply of energy worldwide by the end of this century, as capacity of renewable energy is gradually increasing in the early decades. However, developing nations like Bangladesh are largely reliant on pricey imported energy supplies (coal, gas, and oil) that lay a heavy weight on the country’s economy. Also, air pollution growing in importance as a national and international environmental issue. Regarding the development of clean and sustainable energy, renewable energy sources seem to be among the most practical and efficient alternatives, in both Bangladesh and globally. The geographic advantages of Bangladesh allow for widespread usage of the majority of such renewable energy sources. The comparative potential and use of fossil fuels against renewable energy sources globally and in Bangladesh is explored in this review. 展开更多
关键词 Renewable energy Solar and Photovoltaics HYDROPOWER Wind energy GEOTHERMAL
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Diagnosis of the Kinetic Energy of the“21·7”Extreme Torrential Rainfall Event in Henan Province,China
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作者 Xiuping YAO Ruoying LI +1 位作者 Xiaohong BAO Qiaohua LIU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期73-83,共11页
An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(... An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(K),which can be divided into rotational wind(V_(R))kinetic energy(K_(R)),divergent wind kinetic energy(K_(D)),and the kinetic energy of the interaction between the divergent and rotational winds(K_(RD)).According to the hourly precipitation intensity variability,the ETR process was divided into an initial stage,a rapid increase stage,and maintenance stage.Results showed that the intensification and maintenance of ETR were closely related to the upper-level K,and most closely related to the upperlevel K_(R),with a correlation coefficient of up to 0.9.In particular,the peak value of hourly rainfall intensity lagged behind the K_(R) by 8 h.Furthermore,diagnosis showed that K transformation from unresolvable to resolvable scales made the ETR increase slowly.The meridional rotational wind(u_(R))and meridional gradient of the geopotential(φ)jointly determined the conversion of available potential energy(APE)to K_(R) through the barotropic process,which dominated the rapid enhancement of K_(R) and then caused the rapid increase in ETR.The transportation of K by rotational wind consumed K_(R),and basically offset the K_(R) produced by the barotropic process,which basically kept K_(R) stable at a high value,thus maintaining the ETR. 展开更多
关键词 extreme torrential rain rotational kinetic energy kinetic energy generation and transport barotropic process
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Heuristic Estimation of the Vacuum Energy Density of the Universe: Part II-Analysis Based on Frequency Domain Electromagnetic Radiation
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作者 Vernon Cooray Gerald Cooray +1 位作者 Marcos Rubinstein Farhad Rachidi 《Journal of Electromagnetic Analysis and Applications》 2024年第1期1-9,共9页
In Part I of this paper, an inequality satisfied by the vacuum energy density of the universe was derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according ... In Part I of this paper, an inequality satisfied by the vacuum energy density of the universe was derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to a constant and relativistic speed at a distance L from a perfectly conducting plane. The charge of the electron was represented by a spherical charge distribution located within the Compton wavelength of the electron. Subsequently, the electron is incident on the perfect conductor giving rise to transition radiation. The energy associated with the transition radiation depends on the parameter L. It was shown that an inequality satisfied by the vacuum energy density will emerge when the length L is pushed to cosmological dimensions and the product of the radiated energy, and the time duration of emission is constrained by Heisenberg’s uncertainty principle. In this paper, a similar analysis is conducted with a chain of electrons oscillating sinusoidally and located above a conducting plane. In the thought experiment presented in this paper, the behavior of the energy radiated by the chain of oscillating electrons is studied in the frequency domain as a function of the length L of the chain. It is shown that when the length L is pushed to cosmological dimensions and the energy radiated within a single burst of duration of half a period of oscillation is constrained by the fact that electromagnetic energy consists of photons, an inequality satisfied by the vacuum energy density emerges as a result. The derived inequality is given by where is the vacuum energy density. This result is consistent with the measured value of the vacuum energy density, which is 5.38 × 10<sup>-10</sup> J/m. The result obtained here is in better agreement with experimental data than the one obtained in Part I of this paper with time domain radiation. 展开更多
关键词 Classical Electrodynamics Electromagnetic Radiation Action Radiated energy PHOTON Heisenberg’s Uncertainty Principle Dark energy Vacuum energy Cosmological Constant Hubble Radius
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