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Analysis for Effects of Temperature Rise of PV Modules upon Driving Distance of Vehicle Integrated Photovoltaic Electric Vehicles
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作者 Masafumi Yamaguchi Yasuyuki Ota +18 位作者 Taizo Masuda Christian Thiel Anastasios Tsakalidis Arnulf Jaeger-Waldau Kenji Araki Kensuke Nishioka Tatsuya Takamoto Takashi Nakado Kazumi Yamada Tsutomu Tanimoto Yosuke Tomita Yusuke Zushi Kenichi Okumura Takashi Mabuchi Akinori Satou Kyotaro Nakamura Ryo Ozaki Nobuaki Kojima Yoshio Ohshita 《Energy and Power Engineering》 2024年第4期131-150,共20页
The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO<sub>2</sub> emissions from the transport sector to realize a decarbonized society. Although ... The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO<sub>2</sub> emissions from the transport sector to realize a decarbonized society. Although long-distance driving of VIPV-EV without electricity charging is expected in sunny regions, driving distance of VIPV-EV is affected by climate conditions such as solar irradiation and temperature rise of PV modules. In this paper, detailed analytical results for effects of climate conditions such as solar irradiation and temperature rise of PV modules upon driving distance of the VIPV-EV were presented by using test data for Toyota Prius and Nissan Van demonstration cars installed with high-efficiency InGaP/GaAs/InGaAs 3-junction solar cell modules with a module efficiency of more than 30%. The temperature rise of some PV modules studied in this study was shown to be expressed by some coefficients related to solar irradiation, wind speed and radiative cooling. The potential of VIPV-EV to be deployed in 10 major cities was also analyzed. Although sunshine cities such as Phoenix show the high reduction ratio of driving range with 17% due to temperature rise of VIPV modules, populous cities such as Tokyo show low reduction ratio of 9%. It was also shown in this paper that the difference between the driving distance of VIPV-EV driving in the morning and the afternoon is due to PV modules’ radiative cooling. In addition, the importance of heat dissipation of PV modules and the development of high-efficiency PV modules with better temperature coefficients was suggested in order to expand driving range of VIPV-EV. The effects of air-conditioner usage and partial shading in addition to the effects of temperature rise of VIPV modules were suggested as the other power losses of VIPV-EV. 展开更多
关键词 Vehicle Integrated Photovoltaics (VIPV) VIPV-Powered Electric Vehicles Driving Distance PV Modules Solar Irradiation temperature rise Radiative Cooling
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Feasibility Research of Using Phase Change Materials to Reduce the Inner Temperature Rise of Mass Concrete 被引量:3
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作者 钱春香 GAO Guibo +1 位作者 HE Zhihai 李瑞阳 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第5期989-994,共6页
In order to evaluate the feasibility of using phase change materials to reduce the inner temperature rise of mass concrete, the interior temperature of normal concrete specimen under semi-adiabatic curing condition wa... In order to evaluate the feasibility of using phase change materials to reduce the inner temperature rise of mass concrete, the interior temperature of normal concrete specimen under semi-adiabatic curing condition was measured. The effect of embedding phase change material(PCM) and replacing water with suspension of phase change material(SPCM) as cooling fluid were compared in the experiment. The cooling effect and the affecting factors were analyzed and calculated. The research results showed that the peak of inner temperature could be decreased obviously by the method of pre-embeding PCM in concrete, however, this method is only effective in the initial stage of cement hydration process. Besides, the volume of PCM is rather big and the PCM can not be used circularly, which means that this method can only be used under special condition and the feasibility is low. When SPCM was used as cooling fluid, the interior temperature rise of mass concrete was reduced more effectively, and the temperature grads peak around the cooling pipe was also reduced. Besides, both the SPCM consumption amount and the circulation time were decreased, and most important is that the SPCM is recyclable. The technical and economical feasibility of using SPCM to reduce the inner temperature rise of mass concrete is high. 展开更多
关键词 phase change material suspension of phase change material mass concrete interior temperature rise FEASIBILITY
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Estimation of Critical Rate of Temperature Rise for Thermal Explosion of First Order Autocatalytic Decomposition Reaction Systems by Using Non-isothermal DSC 被引量:1
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作者 GUOPeng-jiang HURong-zu +8 位作者 ZHANGHai XIAZhi-ming SONGJi-rong GAOSheng-li NINGBin-ke SHIQi-zhen LIURong LUGui-e JIANGJi-you 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第2期163-165,共3页
A method of estimating the critical rate of temperature rise for the thermal explosion of first order autocatalytic decomposition reaction systems by using non-isothermal DSC is presented. The information was obtained... A method of estimating the critical rate of temperature rise for the thermal explosion of first order autocatalytic decomposition reaction systems by using non-isothermal DSC is presented. The information was obtained on the increasing rate of temperature for the first order autocatalytic decomposition of nitrocellulose containing 13.86% nitrogen converting into the thermal explosion. 展开更多
关键词 DSC Critical rate of temperature rise NC Non-isothermal change thermal explosion
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Influence of Particles on the Loading Capacity and the Temperature Rise of Water Film in Ultra-high Speed Hybrid Bearing 被引量:3
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作者 ZHU Aibin LI Pei +2 位作者 ZHANG Yefan CHEN Wei YUAN Xiaoyang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第3期541-548,共8页
Ultra-high speed machining technology enables high efficiency, high precision and high integrity of machined surface. Previous researches of hybrid bearing rarely consider influences of solid particles in lubricant an... Ultra-high speed machining technology enables high efficiency, high precision and high integrity of machined surface. Previous researches of hybrid bearing rarely consider influences of solid particles in lubricant and ultra-high speed of hybrid bearing, which cannot be ignored under the high speed and micro-space conditions of ultra-high speed water-lubricated hybrid bearing. Considering the impact of solid particles in lubricant, turbulence and temperature viscosity effects of lubricant, the influences of particles on pressure distribution, loading capacity and the temperature rise of the lubricant film with four-step-cavity ultra-high speed water-lubricated hybrid bearing are presented in the paper. The results show that loading capacity of the hybrid bearing can be affected by changing the viscosity of the lubricant, and large particles can improve the bearing loading capacity higher. The impact of water film temperature rise produced by solid particles in lubricant is related with particle diameter and minimum film thickness. Compared with the soft particles, hard particles cause the more increasing of water film temperature rise and loading capacity. When the speed of hybrid bearing increases, the impact of solid particles on hybrid bearing becomes increasingly apparent, especially for ultra-high speed water-lubricated hybrid bearing. This research presents influences of solid particles on the loading capacity and the temperature rise of water film in ultra-high speed hybrid bearings, the research conclusions provide a new method to evaluate the influence of solid particles in lubricant of ultra-high speed water-lubricated hybrid bearing, which is important to performance calculation of ultra-high speed hybrid bearings, design of filtration system, and safe operation of ultra-high speed hybrid bearings. 展开更多
关键词 hybrid bearing liquid-solid flow solid particles loading capacity temperature rise
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The Method for Measuring the Loop Resistance and the Temperature Rise Calculation of GIS Conductor Pole 被引量:1
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作者 Li Zhou Tiecheng Lu Bo Zhang 《Journal of Power and Energy Engineering》 2015年第4期306-312,共7页
This paper studies the method for measuring the loop resistance of GIS conductor pole based on the super capacitor producing impulse current up to several thousand amperes. This method overcomes the limitations of con... This paper studies the method for measuring the loop resistance of GIS conductor pole based on the super capacitor producing impulse current up to several thousand amperes. This method overcomes the limitations of conventional diagnostic method. Typical GIS conductor poles are chosen. Based on FEA and lab tests, the effect of different forms of current and contact condition, relationship between the temperature of contact and the loop resistance is researched. In full- scale testing under realistic operating conditions on the new 220 kV GIS using prototype instrumentation a very good sensitivity in an early stage was obtained. 展开更多
关键词 the METHOD for MEASURING the Loop Resistance and the temperature rise CALCULATION of GIS Conductor POLE
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A THEORETICAL CALCULATION OF TEMPERATURE RISE(TR) IN PIPELINE OF COOL-SUPPLY SYSTEM
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作者 吴植华 林绍基 杨东华 《Journal of China Textile University(English Edition)》 EI CAS 1995年第1期67-74,共8页
In the design of cool-supply system, the temperature rise of cooling water pipeline is usually determined by experience, but not calculated. In gcnacral, the temperature rise is 1℃ for cooling water supply pipes and ... In the design of cool-supply system, the temperature rise of cooling water pipeline is usually determined by experience, but not calculated. In gcnacral, the temperature rise is 1℃ for cooling water supply pipes and 0.5℃ for return pipes. The calculated results of TR according to classical approaches of thermodynamics are smaller than the tested data. This paper has analysed the causes that affect the temperature rise in detail. The heat transfer of pipe wall and the pressure drop in pipeline are two main factors. Besides, the paper gives another five factors as follows: 1. The heat radiation from the sun to pipelines; 2. The increased heat transfer due to the water condensation around the outer wall of pipelines; 3. For the underground pipelines, the existing unstable heat transfer; 4. The effects of insulation material as well as the installed quality of insulation layer; 5.The additional cool loss produced by the accessories, such as valves, brace etc. According to the above analysis, the paper 展开更多
关键词 temperature rise HEAT transfer HEAT radiation effect of INSULATION
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A MODIFIED THERMAL VISCOPLASTIC CONSTITUTIVE LAW INVOLVING THE EFFECT OF TEMPERATURE RISE RATE
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作者 Huang, CG Duan, ZP 《Acta Mechanica Solida Sinica》 SCIE EI 2000年第2期141-148,共8页
At high temperature rise rate, the mechanical properties of 10 # steel were determined experimentally in a very wide range of temperature and strain rates. A new constitutive relationship was put forward, which can fi... At high temperature rise rate, the mechanical properties of 10 # steel were determined experimentally in a very wide range of temperature and strain rates. A new constitutive relationship was put forward, which can fit with the experimental results and describe various phenomena observed in our experiments. Meanwhile, some interesting characteristics about the temperature rise rate, strain and strain rate hardening and thermal softening are also shown in this paper. Finally, the reliability of the constitutive law and the correctness of the constitutive parameters were verified by comparing the calculation results with the experimental data. 展开更多
关键词 constitutive law strain rate temperature rise rate
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Analysis of Temperature Rise in High-Speed Permanent Magnet Synchronous Traction Motors by Coupling the Equivalent Thermal Circuit Method and Computational Fluid Dynamics
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作者 Jungang Jia 《Fluid Dynamics & Materials Processing》 EI 2020年第5期919-933,共15页
To solve the problem of temperature rise caused by the high power density of high-speed permanent magnet synchronous traction motors,the temperature rise of various components in the motor is analyzed by coupling the ... To solve the problem of temperature rise caused by the high power density of high-speed permanent magnet synchronous traction motors,the temperature rise of various components in the motor is analyzed by coupling the equivalent thermal circuit method and computational fluid dynamics.Also,a cooling strategy is proposed to solve the problem of temperature rise,which is expected to prolong the service life of these devices.First,the theoretical bases of the approaches used to study heat transfer and fluid mechanics are discussed,then the fluid flow for the considered motor is analyzed,and the equivalent thermal circuit method is introduced for the calculation of the temperature rise.Finally,the stator,rotor loss,motor temperature rise,and the proposed cooling method are also explored through experiments.According to the results,the stator temperature at 50,000 r/min and 60,000 r/min at no-load operation is 68℃ and 76℃,respectively.By monitoring the temperature of the air outlets inside and outside the motor at different speeds,it is also found that the motor reaches a stable temperature rise after 65 min of operation.Coupling of the thermal circuit method and computational fluid dynamics is a strategy that can provide the average temperature rise of each component and can also comprehensively calculate the temperature of each local point.We conclude that a hybrid cooling strategy based on axial air cooling of the inner air duct of the motor and water cooling of the stator can meet the design requirements for the ventilation and cooling of this type of motors. 展开更多
关键词 thermal circuit method computational fluid dynamics high-speed permanent magnet synchronous traction motor rotor temperature rise stator temperature rise
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Correlation Analysis of Wind Turbine Temperature Rise and Exergy Efficiency Based on Field-Path Coupling
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作者 Caifeng Wen Qiang Wang +4 位作者 Yang Cao Liru Zhang Wenxin Wang Boxin Zhang Qian Du 《Energy Engineering》 EI 2023年第7期1603-1619,共17页
To solve the problems of large losses and low productivity of permanent magnet synchronous generators used in wind power systems,the field-circuit coupling method is used to accurately solve the electromagnetic field ... To solve the problems of large losses and low productivity of permanent magnet synchronous generators used in wind power systems,the field-circuit coupling method is used to accurately solve the electromagnetic field and temperature field of the generator.The loss distribution of the motor is accurately obtained by considering the influence of external circuit characteristics on its internal physical field.By mapping the losses to the corresponding part of the three-dimensional finite element model of the motor,the temperature field is solved,and the global temperature distribution of the generator,considering the influence of end windings,is obtained.By changing the air gap length,permanent magnet thickness,and winding conductivity,the relationship between the loss,temperature rise,and exergy efficiency can be obtained.By optimizing the air gap length,permanent magnet thickness,and winding conductivity,the best configuration and material properties can improve the efficiency of the motor by up to 4%. 展开更多
关键词 Wind turbine field-path coupling temperature rise distribution exergy efficiency
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Effects of vapour bubbles on acoustic and temperature distributions of therapeutic ultrasound 被引量:2
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作者 范庭波 章东 +2 位作者 张喆 马勇 龚秀芬 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第9期3372-3377,共6页
This paper describes the evolution of vapour bubbles and its effect on nonlinear ultrasound propagation and temperature rise through tissues for therapeutic ultrasound. An acoustic-thermo coupling algorithm incorporat... This paper describes the evolution of vapour bubbles and its effect on nonlinear ultrasound propagation and temperature rise through tissues for therapeutic ultrasound. An acoustic-thermo coupling algorithm incorporating nonlinearity, diffraction, and temperature-dependent tissue properties, is employed to describe nonlinear ultrasound propagation and thermal effect. Results demonstrate that an obvious migration of peak pressure toward transducer surface is observed while the position of peak temperature changes little in liver tissue before the generation of vapour bubbles, and that the boiling region enlarges towards the surface of transducer in axial direction but increases slowly in radial direction after the generation of vapour bubbles. 展开更多
关键词 vapour bubbles ultrasound propagation temperature rise
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Effect of quenching temperature on the microstructure of Si-containing steel during quenching and partitioning 被引量:1
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作者 WANG Huanrong WANG Wei +1 位作者 YANG Ana WANG Guodong 《Baosteel Technical Research》 CAS 2015年第2期18-24,共7页
This study aims to investigate the effect of the 1-step quenching and partitioning (Q&P) process on the microstructure and the resulting Vicker' s hardness of 0.3C-1.5Si-1.5Mn steel by using in-situ dilatometry ,o... This study aims to investigate the effect of the 1-step quenching and partitioning (Q&P) process on the microstructure and the resulting Vicker' s hardness of 0.3C-1.5Si-1.5Mn steel by using in-situ dilatometry ,optical microscopy ( OM ), scanning electron microscopy ( SEM ), X-ray diffractometry ( XRD ), and Vicker ' s hardness measurement. Systematic analyses indicate that the microstructure of the specimens quenched and partitioned at 150℃ ,200 ℃ ,250℃ ,and 300℃ mainly comprises lath martensite and retained austenite. The dilatometry curve of the specimen partitioned at 150℃ is presumably ascribed to the formation of isothermal martensite. In the early stages of partitioning at 200℃,the nearly unchanged dilatation curve is closely related to the synergistic effect of isothermal martensite formation and transitional epsilon carbide precipitation. In the later stages of partitioning at 200 ℃ ,the slight increase in the dilatation curve is due to the continuous isothermal martensite formation. With further increase in partitioning temperature to 250℃, the dilatation increases gradually up to 3600 s, which is related to carbon partitioning and lower bainite formation. Partitioning at a higher temperature of 300 ℃ causes a rapid increase in the dilatation curve during the initial stages, which subsequently levels off upon prolonging the partitioning time. This is mainly attributed to the rapid diffusion of carbon from athermal martensite to retained austenite and continuous formation of lower bainite. 展开更多
关键词 quenching temperature 1 -step quenching and partitioning 1 -step Q&P) dilatometry SEM
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Study on Carburizing and Temperature Rising of the Semi-Steel Melt with Plasma Heating
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作者 Yuan Zhangfu Zeng Jiaqing +2 位作者 Huang Daochang Wan Tianji Fan Yousan 《Journal of Iron and Steel Research(International)》 SCIE EI CAS CSCD 1997年第1期19-21,共3页
Experiments were carried out on carburizing and temperature rising of the semi steel melt in a plasma induction furnace.Influence of many factors, such as power supply mode,position of the plasma torch and bottom b... Experiments were carried out on carburizing and temperature rising of the semi steel melt in a plasma induction furnace.Influence of many factors, such as power supply mode,position of the plasma torch and bottom blown gas stirring,on heating efficiency and melt temperature distribution was studied. Melt temperature could be effectively controlled by plasma heating,and carbon content of semi steel melt increased from 1.92 % to 4.58 %, and the utilization rate of carbon reached up to 61.57 % during carburizing of the melt. 展开更多
关键词 plasma heating CARBURIZING temperature rising semi steel melt
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Three-Dimensional Mantle Flow and Temperature Structure Beneath the Shatsky Rise Ridge-Ridge-Ridge Triple Junction
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作者 ZHANG Jinchang ZHOU Zhiyuan +1 位作者 DING Min LIN Jian 《Journal of Ocean University of China》 SCIE CAS CSCD 2021年第4期857-865,共9页
The Shatsky Rise ridge-ridge-ridge triple junction is an ancient triple junction in the Western Pacific Ocean whose initial geodynamic process is poorly understood and can only be inferred based on indirect geological... The Shatsky Rise ridge-ridge-ridge triple junction is an ancient triple junction in the Western Pacific Ocean whose initial geodynamic process is poorly understood and can only be inferred based on indirect geological and geophysical constraints.In this paper,we present three-dimensional numerical models that simulate the Shatsky Rise triple junction and calculate its coupled mantle flow and temperature structure.The mantle flow velocity field shows several distinctive features:1)stronger mantle upwelling closer to the ridge axis and triple junction;2)greater upwelling velocity at the faster-spreading ridges;and 3)the most significant increase in upwelling velocity for the slowest-spreading ridge toward the triple junction.The calculated mantle temperature field also reveals distinctive characteristics:1)sharp increases in the mantle temperature with depth and increases toward the spreading ridges and triple junction;2)the faster-spreading ridges are associated with higher temperatures at depth and identical distances from the triple junction;and 3)the slowest-spreading ridge shows the greatest increase in the along-ridge-axis temperature toward the triple junction.Compared to many present-day triple junctions with slower spreading rates,the along-ridge-axis velocity and thermal fields of the Shatsky Rise are more altered due to the presence of the triple junction. 展开更多
关键词 triple junction mid-ocean ridge Shatsky rise numerical modeling mantle flow mantle temperature
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A Simulation of the Response of a Sounding Temperature Sensor Based on the Combination of a Genetic Algorithm and Computational Fluid Dynamics
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作者 Juanjuan Wang Yajuan Jia Jiangping Nan 《Fluid Dynamics & Materials Processing》 EI 2020年第6期97-111,共15页
The present study aims at improving the accuracy of weather forecast by providing useful information on the behavior and response of a sounding temperature sensor.A hybrid approach relying on Computational Fluid Dynam... The present study aims at improving the accuracy of weather forecast by providing useful information on the behavior and response of a sounding temperature sensor.A hybrid approach relying on Computational Fluid Dynamics and a genetic algorithm(GA)is used to simulate the system represented by the bead thermistor and the surrounding air.In particular,the influence of different lead angles,sensor lead length,and lead number is considered.The results have shown that when the length of the lead wire of the bead thermistor is increased,the radiation temperature rise is reduced;when the number of lead wire is four and the angle between the lead wires is 180°,the solar radiation angle has a scarce influence on the radiation temperature rise of the sounding temperature sensor. 展开更多
关键词 Sounding temperature sensor genetic algorithm radiation temperature rise computational fluid dynamics bead thermistor
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The Significant and Profound Impacts of Chou’s 5-Steps Rule 被引量:1
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作者 Kuo-Chen Chou 《Natural Science》 2020年第9期633-637,共5页
In this short review paper, the significant and profound impacts of the 5-steps rule have <span style="mso-bookmark:OLE_LINK2;"><span style="mso-bookmark:OLE_LINK1;"><span lang="... In this short review paper, the significant and profound impacts of the 5-steps rule have <span style="mso-bookmark:OLE_LINK2;"><span style="mso-bookmark:OLE_LINK1;"><span lang="EN-US" style="line-height: 97%;font-family:;" capt",serif;font-size:11pt;"="" pro="" minion="">been briefly recalled with crystal clear convincingness.</span></span></span> 展开更多
关键词 5-step Rules Significant Impacts Profound Impacts Curie temperature
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Mild spring temperature rising affects the anti-oxidation and immune functions of Asian Short-toed Larks
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作者 Na Zhu Tingting Liu +2 位作者 Fei Wang Wei Liang Shuping Zhang 《Avian Research》 CSCD 2020年第2期115-121,共7页
Background:Predicting the possibility of severe effects of global warming on animals is important for understanding the ecological consequences of climate change on ecosystem.Spring is the season during which birds ha... Background:Predicting the possibility of severe effects of global warming on animals is important for understanding the ecological consequences of climate change on ecosystem.Spring is the season during which birds have to physiologically prepare for the subsequent breeding period,and unusual spring temperature rising probably becomes a heat stress to the birds which have adapted to the low spring temperature.Therefore,it is necessary to understand the physiological effect of spring warming on the temperate birds.Methods:Using the activities of blood anti-oxidative enzymes(SOD,CAT,GPx)and the concentrations of serum immunogloblins(IgA,IgY,IgM)as indicators,we compared the anti-oxidative and immune functions of Asian Shorttoed Larks(Calandrella cheleensis)captured between 10 and 15 March,2015 and housed under conditions of 21°C and 16°C.Results:The SOD activities of birds in 21°C group were significantly lower than those in 16°C group on all the treatment days.The CAT activities of the birds in 21°C group were significantly lower than those in 16°C group on the 1 st,5 th,13 th,17 treatment days.The GPx activities of the birds in 21°C group were signifthicantly lower than those in 16°C group on the 1 st,13 th and 17 th,but significantly higher on the 21 st treatment day.The IgA,IgY and IgM concentrations of birds in 21°C group were significantly lower than those in 16°C group on all the treatment days.Conclusions:This study shows that spring temperature rising negatively influences antioxibative and humoral immune functions,which indicates that spring climate warming might reduce the fitness of the temperate passerine birds which have adapted to the low spring temperature. 展开更多
关键词 Mild temperature rising Anti-oxidant capacity Immunity Asian Short-toed Larks Spring
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Influence of mode conversions in the skull on transcranial focused ultrasound and temperature fields utilizing the wave field separation method: A numerical study
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作者 王祥达 林伟军 +1 位作者 苏畅 王秀明 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期401-414,共14页
Transcranial focused ultrasound is a booming noninvasive therapy for brain stimuli. The Kelvin–Voigt equations are employed to calculate the sound field created by focusing a 256-element planar phased array through a... Transcranial focused ultrasound is a booming noninvasive therapy for brain stimuli. The Kelvin–Voigt equations are employed to calculate the sound field created by focusing a 256-element planar phased array through a monkey skull with the time-reversal method. Mode conversions between compressional and shear waves exist in the skull. Therefore, the wave field separation method is introduced to calculate the contributions of the two waves to the acoustic intensity and the heat source, respectively. The Pennes equation is used to depict the temperature field induced by ultrasound. Five computational models with the same incident angle of 0?and different distances from the focus for the skull and three computational models at different incident angles and the same distance from the focus for the skull are studied. Numerical results indicate that for all computational models, the acoustic intensity at the focus with mode conversions is 12.05%less than that without mode conversions on average. For the temperature rise, this percentage is 12.02%. Besides, an underestimation of both the acoustic intensity and the temperature rise in the skull tends to occur if mode conversions are ignored. However, if the incident angle exceeds 30?, the rules of the over-and under-estimation may be reversed. Moreover,shear waves contribute 20.54% of the acoustic intensity and 20.74% of the temperature rise in the skull on average for all computational models. The percentage of the temperature rise in the skull from shear waves declines with the increase of the duration of the ultrasound. 展开更多
关键词 transcranial focused ultrasound temperature rise mode conversion wave field separation
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Analysis of the effects of rising temperature for embankments under seismic loads in cold regions
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作者 ZhiQiang Liu 1,2,Hao Lu 1 1.School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China.2.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China. 《Research in Cold and Arid Regions》 2009年第4期316-321,共6页
The effect of temperature rising for frozen soil because of dynamic load was investigated by indoor tests.Roadway and railway embankments are always loaded by dynamic loads such as earthquakes and vehicles.Because the... The effect of temperature rising for frozen soil because of dynamic load was investigated by indoor tests.Roadway and railway embankments are always loaded by dynamic loads such as earthquakes and vehicles.Because the Qinghai-Tibetan Plateau is a re-gion where earthquakes occur frequently,it is essential to consider the temperature-rising effect of earthquakes or vehicles on railway and road embankment.In this paper and according to the theories of heat transfer and dynamic equilibrium equations,as-suming frozen soil as thermal elastic-viscoplastic material,taking the combination of thermal and mechanical stresses into account,we present the numerical formulae of this dynamic problem,and the computer program of the two-dimensional finite element is written.Using the program,the dynamic response analyses for embankments loaded by earthquake are worked out.Analysis in-dicated that the temperature-rising effect result from earthquakes for embankment in nonuniform distribution in some small areas,the maximum rising temperature is 0.16 ?C for consideration in this paper. 展开更多
关键词 Qinghai-Tibetan railway temperature-rising effect frozen soil EMBANKMENT
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A review on the generation, determination and mitigation of Urban Heat Island 被引量:119
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作者 RIZWAN Ahmed Memon DENNIS Y.C. Leung LIU Chunho 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第1期120-128,共9页
Urban Heat Island (UHI) is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. The large amount of heat generate... Urban Heat Island (UHI) is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. The large amount of heat generated from urban structures, as they consume and re-radiate solar radiations, and from the anthropogenic heat sources are the main causes of UHI. The two heat sources increase the temperatures of an urban area as compared to its surroundings, which is known as Urban Heat Island Intensity (UHII). The problem is even worse in cities or metropolises with large population and extensive economic activities. The estimated three billion people living in the urban areas in the world are directly exposed to the problem, which will be increased significantly in the near future. Due to the severity of the problem, vast research effort has been dedicated and a wide range of literature is available for the subject. The literature available in this area includes the latest research approaches, concepts, methodologies, latest investigation tools and mitigation measures. This study was carded out to review and summarize this research area through an investigation of the most important feature of UHI. It was concluded that the heat re-radiated by the urban structures plays the most important role which should be investigated in details to study urban heating especially the UHI. It was also concluded that the future research should be focused on design and planning parameters for reducing the effects of urban heat island and ultimately living in a better environment. 展开更多
关键词 urban heat island (UHI) URBANIZATION temperature rise MITIGATION
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ANALYSIS OF THERMAL-ELASTIC STRESS OF WHEEL-RAIL IN ROLLING-SLIDING CONTACT 被引量:4
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作者 ZHAO Xin JIN Xuesong ZHAI Wanming 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第3期18-23,共6页
A coupling thermo-mechanical model of wheel/rail in rolling-sliding contact is put forward using finite element method. The normal contact pressure is idealized as the Hertzian distribution, and the tangential force p... A coupling thermo-mechanical model of wheel/rail in rolling-sliding contact is put forward using finite element method. The normal contact pressure is idealized as the Hertzian distribution, and the tangential force presented by Carter is used. In order to obtain thermal-elastic stress, the ther-mal-elastic plane stress problem is transformed to an elastic plane stress problem with equivalent fictitious thermal body force and fictitious boundary distributed force. The temperature rise and ther-mal-elastic stress of wheel and rail in rolling-sliding are analyzed. The non-steady state heat transfer between the contact surfaces of wheel and rail, heat-convection and radiation between the wheel/rail and the ambient are taken into consideration. The influences of the wheel rolling speed and wear rate on friction temperature and thermal-elastic stress are investigated. The results show the following: ① For rolling-sliding case, the thermal stress in the thin layer near the contact patch due to the friction temperature rise is severe. The higher rolling speed leads to the lower friction temperature rise and thermal stress in the wheel; ② For sliding case, the friction temperature and thermal stress of the wheel rise quickly in the initial sliding stage, and then get into a steady state gradually. The expansion of the contact patch, due to material wear, can affect the friction temperature rise and the thermal stress during wear process. The higher wear rate generates lower stress. The results can help under-stand the influence of friction temperature and thermal-elastic stress on wheel and rail damage. 展开更多
关键词 Wheel/rail fiiction thermal stress temperature rise Heat transfer Finite element method
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