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Using satellite-derived land surface temperatures to clarify the spatiotemporal warming trends of the Alborz Mountains in northern Iran
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作者 ROSHAN Gholamreza SARLI Reza +2 位作者 GHANGHERMEH Abdolazim TAHERIZADEH Mehrnoosh NIKNAM Arman 《Journal of Mountain Science》 SCIE CSCD 2024年第2期449-469,共21页
The Alborz Mountains are some of the highest in Iran,and they play an important role in controlling the climate of the country’s northern regions.The land surface temperature(LST)is an important variable that affects... The Alborz Mountains are some of the highest in Iran,and they play an important role in controlling the climate of the country’s northern regions.The land surface temperature(LST)is an important variable that affects the ecosystem of this area.This study investigated the spatiotemporal changes and trends of the nighttime LST in the western region of the Central Alborz Mountains at elevations of 1500-4000 m above sea level.MODIS data were extracted for the period of 2000-2021,and the Mann-Kendall nonparametric test was applied to evaluating the changes in the LST.The results indicated a significant increasing trend for the monthly average LST in May-August along the southern aspect.Both the northern and southern aspects showed decreasing trends for the monthly average LST in October,November,and March and an increasing trend in other months.At all elevations,the average decadal change in the monthly average LST was more severe along the southern aspect(0.60°C)than along the northern aspect(0.37°C).The LST difference between the northern and southern aspects decreased in the cold months but increased in the hot months.At the same elevation,the difference in the lapse rate between the northern and southern aspects was greater in the hot months than in the cold months.With increasing elevation,the lapse rate between the northern and southern aspects disappeared.Climate change was concluded to greatly decrease the difference in LST at different elevations for April-July. 展开更多
关键词 Global warming Mountainous areas Lapse rate Surface air temperatures ALBORZ
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Predictive modeling of critical temperatures in magnesium compounds using transfer learning
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作者 Surjeet Kumar Russlan Jaafreh +4 位作者 Subhajit Dutta Jung Hyeon Yoo Santiago Pereznieto Kotiba Hamad Dae Ho Yoon 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第4期1540-1553,共14页
This study presents a transfer learning approach for discovering potential Mg-based superconductors utilizing a comprehensive target dataset.Initially,a large source dataset(Bandgap dataset)comprising approximately∼7... This study presents a transfer learning approach for discovering potential Mg-based superconductors utilizing a comprehensive target dataset.Initially,a large source dataset(Bandgap dataset)comprising approximately∼75k compounds is utilized for pretraining,followed by fine-tuning with a smaller Critical Temperature(T_(c))dataset containing∼300 compounds.Comparatively,there is a significant improvement in the performance of the transfer learning model over the traditional deep learning(DL)model in predicting Tc.Subsequently,the transfer learning model is applied to predict the properties of approximately 150k compounds.Predictions are validated computationally using density functional theory(DFT)calculations based on lattice dynamics-related theory.Moreover,to demonstrate the extended predictive capability of the transfer learning model for new materials,a pool of virtual compounds derived from prototype crystal structures from the Materials Project(MP)database is generated.T_(c) predictions are obtained for∼3600 virtual compounds,which underwent screening for electroneutrality and thermodynamic stability.An Extra Trees-based model is trained to utilize E_(hull)values to obtain thermodynamically stable materials,employing a dataset containing Ehull values for approximately 150k materials for training.Materials with Ehull values exceeding 5 meV/atom were filtered out,resulting in a refined list of potential Mg-based superconductors.This study showcases the effectiveness of transfer learning in predicting superconducting properties and highlights its potential for accelerating the discovery of Mg-based materials in the field of superconductivity. 展开更多
关键词 SUPERCONDUCTIVITY Critical temperature Transfer learning Crystal structure features Thermodynamic stability
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Dependence of impact regime boundaries on the initial temperatures of projectiles and targets
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作者 Stefano Signetti Andreas Heine 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期49-57,共9页
Towards higher impact velocities,ballistic events are increasingly determined by the material temperatures.Related effects might range from moderate thermal softening to full phase transition.In particular,it is of gr... Towards higher impact velocities,ballistic events are increasingly determined by the material temperatures.Related effects might range from moderate thermal softening to full phase transition.In particular,it is of great interest to quantify the conditions for incipient or full melting of metals during impact interactions,which result in a transition from still strength-affected to hydrodynamic material behavior.In this work,we investigate to which extent the respective melting thresholds are also dependent on the initial,and generally elevated,temperatures of projectiles and targets before impact.This is studied through the application of a model developed recently by the authors to characterize the transition regime between high-velocity and hypervelocity impact,for which the melting thresholds of materials were used as the defining quantities.The obtained results are expected to be of general interest for ballistic application cases where projectiles or targets are preheated.Such conditions might result,for example,from aerodynamic forces acting onto a projectile during atmospheric flight,explosive shapedcharge-jet formation or armor exposure to environmental conditions.The performed analyses also broaden the scientific understanding of the relevance of temperature in penetration events,generally known since the 1960s,but often not considered thoroughly in impact studies. 展开更多
关键词 Ballistic impact Thermal effects Metallic targets Energy partitioning Homologous temperature
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Development of a RBFNN prediction model for carrot quality based on meteorological temperatures at vegetable stations
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作者 Yu-Tong Yan Zeng-Tao Ji Ce Shi 《Food and Health》 2024年第2期49-57,共9页
To evaluate and predict the quality of carrots during logistics process in North China under extreme temperature conditions,quality indicator changes of carrots were investigated,and temperature-coupled quality predic... To evaluate and predict the quality of carrots during logistics process in North China under extreme temperature conditions,quality indicator changes of carrots were investigated,and temperature-coupled quality prediction models were developed.Seven temperatures were selected from meteorological temperature data by cluster analysis to simulate the changes in extreme temperatures during the short-term transportation of carrots.No carrots rotted during the 48h storage period.Under both isothermal and nonisothermal conditions,weight loss andΔE increased while the firmness and sensory evaluation(SE)decreased.The RBFNN performed better than the Arrhenius model in predicting weight loss andΔE,with R^(2)>0.97,MSE<0.009 and relative errors within±18%.The results of the predictive confidence level and standardized residual indicated the good performance of the RBFNN model.The temperature-coupled prediction models of RBFNN were promising candidates for predicting the quality of vegetable products and therefore reducing economic loss of vegetable industry. 展开更多
关键词 CARROT Extreme temperatures temperature coupled ARRHENIUS Radial basis function neural network
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Mesopause temperatures and relative densities at midlatitudes observed by the Mengcheng meteor radar 被引量:1
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作者 Wen Yi XiangHui Xue +5 位作者 MaoLin Lu Jie Zeng HaiLun Ye JianFei Wu Chong Wang TingDi Chen 《Earth and Planetary Physics》 CAS CSCD 2023年第6期665-674,共10页
The atmospheric temperatures and densities in the mesosphere and lower thermosphere(MLT)region are essential for studying the dynamics and climate of the middle and upper atmosphere.In this study,we present more than ... The atmospheric temperatures and densities in the mesosphere and lower thermosphere(MLT)region are essential for studying the dynamics and climate of the middle and upper atmosphere.In this study,we present more than 9 years of mesopause temperatures and relative densities estimated by using ambipolar diffusion coefficient measurements observed by the Mengcheng meteor radar(33.4°N,116.5°E).The intercomparison between the meteor radar and Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere by Broadband Emission Radiometry(TIMED/SABER)and Earth Observing System(EOS)Aura/Microwave Limb Sounder(MLS)observations indicates that the meteor radar temperatures and densities agree well with the simultaneous satellite measurements.Annual variations dominate the mesopause temperatures,with the maximum during winter and the minimum during summer.The mesopause relative densities also show annual variations,with strong maxima near the spring equinox and weak maxima before the winter solstice,and with a minimum during summer.In addition,the mesopause density exhibits a structure similar to that of the zonal wind:as the zonal wind flows eastward(westward),the mesopause density decreases(increases).At the same time,the meridional wind shows a structure similar to that of the mesopause temperature:as the meridional wind shows northward(southward)enhancements,the mesopause temperature increases(decreases).Simultaneous horizontal wind,temperature,and density observations provide multiple mesospheric parameters for investigating mesospheric dynamics and thermodynamic processes and have the potential to improve widely used empirical atmospheric models. 展开更多
关键词 meteor radar MESOPAUSE horizontal wind temperature density
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An investigation on failure behavior of semi-flexible composite mixture at different temperatures 被引量:1
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作者 Zijia Xiong Minghui Gong +1 位作者 Jinxiang Hong Lei Zhang 《Journal of Road Engineering》 2023年第2期186-202,共17页
Semi-flexible composite mixture(SFCM)is a kind of pavement material formed by pouring cement-based grout material into a porous asphalt mixture with air voids from 20%to 30%.SFCM is widely used for its outstanding ant... Semi-flexible composite mixture(SFCM)is a kind of pavement material formed by pouring cement-based grout material into a porous asphalt mixture with air voids from 20%to 30%.SFCM is widely used for its outstanding anti-rutting performance.Its mechanical performance is complicated due to its heterogeneity and interlocking structure.According to the present study,asphalt deforms at different temperatures,whereas cement-based grout has no similar characteristics.Rare research focuses on the temperature-based performance of SFCM.Therefore,the study was on the thermal performance of SFCM by seven open-graded asphalt mixture skeletons with different porosities and two types of grouts with early strength(ES)and high strength(HS).The test temperatures ranged from 10℃to 60℃.The mechanical investigation was performed using the semi-circular-bending(SCB)and beam bending tests.The strain sensor was used for analyzing the thermal performance of SFCM.The results show that the temperature significantly affected the SFCM's performance.The porosity was selected for three sections based on the trend of fracture energy(Gf)curves at 25℃.The turning points were the porosity values of 20%and 26%.The initiation slope during elastic deformation increases with the porosity increase.This trend was more evident at intermediate temperature.The shrink strain of SFCM was lower than that of the usual asphalt mixture(AC).The thermal stress of the SFCM filled with HS(HS-SFCM)was higher than that of the SFCM filled with ES(ES-SFCM)at 10℃.Moreover,the thermal failure characteristics of SFCM were influenced by porosity. 展开更多
关键词 Semi-flexible composite mixture temperaturE SCB Strain sensor
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A bHLH transcription factor,CsSPT,regulates high-temperature resistance in cucumber 被引量:1
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作者 Yonggui Liang Chenyu Yang +7 位作者 Fangyan Ming Bingwei Yu Zhihua Cheng Yixi Wang Zhengkun Qiu Xiaolan Zhang Bihao Cao Shuangshuang Yan 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期503-514,共12页
High-temperature stress threatens the growth and yield of crops. Basic helix-loop-helix(bHLH) transcription factors(TFs) have been shown to play important roles in regulating high-temperature resistance in plants. How... High-temperature stress threatens the growth and yield of crops. Basic helix-loop-helix(bHLH) transcription factors(TFs) have been shown to play important roles in regulating high-temperature resistance in plants. However, the bHLH TFs responsible for high-temperature tolerance in cucumbers have not been identified. We used transcriptome profiling to screen the high temperature-responsive candidate bHLH TFs in cucumber. Here, we found that the expression of 75 CsbHLH genes was altered under high-temperature stress. The expression of the CsSPT gene was induced by high temperatures in TT(Thermotolerant) cucumber plants. However, the Csspt mutant plants obtained by the CRISPR-Cas9 system showed severe thermosensitive symptoms, including wilted leaves with brown margins and reduced root density and cell activity.The Csspt mutant plants also exhibited elevated H_(2)O_(2) levels and down-regulated photosystem-related genes under normal conditions.Furthermore, there were high relative electrolytic leakage(REC), malondialdehyde(MDA), glutathione(GSH), and superoxide radical(O_(2)^(·-)) levels in the Csspt mutant plants, with decreased Proline content after the high-temperature treatment. Transcriptome analysis showed that the photosystem and chloroplast activities in Csspt mutant plants were extremely disrupted by the high-temperature stress compared with wildtype(WT) plants. Moreover, the plant hormone signal transduction, as well as MAPK and calcium signaling pathways were activated in Csspt mutant plants under high-temperature stress. The HSF and HSP family genes shared the same upregulated expression patterns in Csspt and WT plants under high-temperature conditions. However, most bHLH, NAC, and bZIP family genes were significantly down-regulated by heat in Csspt mutant plants. Thus, these results demonstrated that CsSPT regulated the high-temperature response by recruiting photosynthesis components, signaling pathway molecules, and transcription factors. Our results provide important insights into the heat response mechanism of CsSPT in cucumber and its potential as a target for breeding heat-resistant crops. 展开更多
关键词 CUCUMBER BHLH CsSPT PHOTOSYNTHESIS High temperature
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Lithium-Sulfur Batteries at Extreme Temperatures:Challenges,Strategies and Prospects
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作者 Wenjia Qu Jingyi Xia +4 位作者 Chong Luo Chen Zhang Renjie Chen Wei Lv Quanhong Yang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第4期297-311,共15页
High-energy-density-batteries working at a wide-temperature range are urgently required in many performance-critical areas.Lithium-sulfur batteries(LSB)are promising high-energy-density batteries that have the potenti... High-energy-density-batteries working at a wide-temperature range are urgently required in many performance-critical areas.Lithium-sulfur batteries(LSB)are promising high-energy-density batteries that have the potential to maintain high performance at extreme temperatures.However,some problems like severe shuttling and safety issues at high temperatures or sluggish reaction kinetics and charge-transfer process at low temperatures decrease the performance and hinder their practical uses in extreme temperature conditions.Therefore,broadening the working temperature of LSB with stable electrochemical performance becomes a crucial topic.In this paper,the key stumbling blocks for high and low-temperature LSB are comprehensively discussed.The solutions from the aspects of electrolyte and electrode materials are discussed to solve the aggravating shuttle effect and thermal safety issues under high temperature and the sluggish reaction kinetics under low temperature.Moreover,some specific promising solutions to extend the operating temperature range of LSB are also proposed and highlighted,which provide potential research directions on the practical LSB application in future. 展开更多
关键词 high temperature lithium-sulfur batteries low temperature safety issue shuttle effect
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Physiological Responses of Clam(Ruditapes philippinarum)to Transport Modes with Different Temperatures
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作者 BI Shijie XUE Changhu +4 位作者 XU Lili WEN Yunqi WANG Lihao LI Zhaojie LIU Hongying 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第2期517-526,共10页
Given the increased circulation time after fishing,a series of changes take place in live clams,leading to a deterioration in quality even after death.Thus,in this study,we aimed to explore the optimal mode of transpo... Given the increased circulation time after fishing,a series of changes take place in live clams,leading to a deterioration in quality even after death.Thus,in this study,we aimed to explore the optimal mode of transportation of clams.The container for holding clams was reformed,and a water circulation temperature control system was established.The physiological responses of clams during anhydrous and watery transportation at two temperatures(4 and 15℃)were investigated based on the aforementioned system.When comparing the transportation patterns after 3 d of transport,a higher survival rate was observed at 4℃(97%)than at 15℃(63%)in the anhydrous transportation groups and a lower survival rate was observed at 4℃(93%)than at 15℃(99%)in the watery transportation groups.In addition,the glycogen content,condition index(CI),and adenylate energy charge(A.E.C)value were higher at4℃((40.87±0.99)mg g^(-1),13.71%±0.50%and 57.45%±1.60%)than at 15℃((30.54±0.81)mg g^(-1),9.09%±0.30%and 43.12%±1.65%)in the anhydrous transportation groups.In the watery transportation groups,a lower glycogen content,CI,and A.E.C.value were observed at 4℃((33.78±0.84)mg g^(-1),9.78%±0.50%and 64.65%±1.25%)than at 15℃((41.53±0.93)mg g^(-1),12.72%±0.83%and 71.58%±1.27%).Results from this study show that anhydrous transportation(4℃)is the optimal transport condition for clams to maintain a high quality and good physiological conditions.Thus,this study will be particularly useful for establishing shellfish transportation systems. 展开更多
关键词 watery transportation anhydrous transportation CLAM physiological response temperaturE
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Seed Priming Improves Enzymatic and Biochemical Performances of Rice During Seed Germination under Low and High Temperatures
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作者 Salar MONAJJEM Elias SOLTANI +4 位作者 Ebrahim ZAINALI Masoud ESFAHANI Farshid GHADERI-FAR Maryam HOSSEINI CHALESHTORI Atefeh REZAEI 《Rice science》 SCIE CSCD 2023年第4期335-347,I0024-I0027,共17页
As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different... As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures.Each of the rice genotypes(Hashemi,Sadry-domsefid,IRON-70-7053-7 and NORIN-22)was primed with hydro-hardening,KCl,CaCl2 and ascorbic acid(AsA)and without a priming agent as a control at low(15℃),optimum(25℃)and high(35℃)germination temperatures.The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents,especially under the low germination temperature.At 15℃,seed priming with AsA was found to be the best agent for the activities of amylase,α-amylase,catalase(CAT),peroxidase(POX),ascorbate peroxidase(APOX)and superoxide dismutase(SOD)as well as the content of soluble sugars in the NORIN-22 genotype,and for protease activity and soluble protein content in the IRON-70-7053-7 genotype.SOD at the low germination temperature and CAT,POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length,vigor index,normal seedling rate and germination rate.Under the priming agents,the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes,and at the high germination temperature under KCl priming in the Hashemi genotype. 展开更多
关键词 antioxidant activity biochemical performance germination temperature RICE seed priming
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Competitive oxidation behavior of Ni-based superalloy GH4738 at extreme temperature 被引量:1
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作者 Hui Xu Shufeng Yang +4 位作者 Enhui Wang Yunsong Liu Chunyu Guo Xinmei Hou Yanling Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期138-145,共8页
A high thrust-to-weight ratio poses challenges to the high-temperature performance of Ni-based superalloys. The oxidation behavior of GH4738 at extreme temperatures has been investigated by isothermal and non-isotherm... A high thrust-to-weight ratio poses challenges to the high-temperature performance of Ni-based superalloys. The oxidation behavior of GH4738 at extreme temperatures has been investigated by isothermal and non-isothermal experiments. As a result of the competitive diffusion of alloying elements, the oxide scale included an outermost porous oxide layer (OOL), an inner relatively dense oxide layer (IOL), and an internal oxide zone (IOZ), depending on the temperature and time. A high temperature led to the formation of large voids at the IOL/IOZ interface. At 1200℃, the continuity of the Cr-rich oxide layer in the IOL was destroyed, and thus, spallation occurred. Extension of oxidation time contributed to the size of Al-rich oxide particles with the increase in the IOZ. Based on this finding,the oxidation kinetics of GH4738 was discussed, and the corresponding oxidation behavior at 900-1100℃ was predicted. 展开更多
关键词 Ni-based superalloy GH4738 extreme temperature competitive oxidation oxidation mechanism oxidation kinetics
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Tensile Properties and Prediction Model of Recombinant Bamboo at Different Temperatures
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作者 Kunpeng Zhao Yang Wei +2 位作者 Si Chen Kang Zhao Mingmin Ding 《Journal of Renewable Materials》 SCIE EI 2023年第6期2695-2712,共18页
The destruction of recombinant bamboo depends on many factors,and the complex ambient temperature is an important factor affecting its basic mechanical properties.To investigate the failure mechanism and stress–strai... The destruction of recombinant bamboo depends on many factors,and the complex ambient temperature is an important factor affecting its basic mechanical properties.To investigate the failure mechanism and stress–strain relationship of recombinant bamboo at different temperatures,eighteen tensile specimens of recombinant bamboo were tested.The results showed that with increasing ambient temperature,the typical failure modes of recombinant bamboo were flush fracture,toothed failure,and serrated failure.The ultimate tensile strength,ultimate strain and elastic modulus of recombinant bamboo decreased with increasing temperature,and the ultimate tensile stress decreased from 154.07 to 96.55 MPa,a decrease of 37.33%,and the ultimate strain decreased from 0.011 to 0.008,a decrease of 26.57%.Based on the Ramberg-Osgood model and the pseudo‒elastic design method,a predictive model was established for the tensile stress–strain relationship of recombinant bamboo considering the temperature level.The model can accurately evaluate the tensile stress–strain relationship of recombinant bamboo under different temperature conditions. 展开更多
关键词 Recombinant bamboo temperaturE tensile behaviour stress-strain relationship predictive model
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Performance in Survival,Development and Reproduction of Aphis glycines Matsumura Virginoparae at High Temperatures
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作者 Liu Jian Liu Zhe +3 位作者 Wu Ci-rui Liu Dai-lin Huo Dong-bo Sun Wen-peng 《Journal of Northeast Agricultural University(English Edition)》 CAS 2023年第1期20-27,共8页
The soybean aphid,Aphis glycines Matsumura,is an important pest of soybean,which is native to Asia.In this study,A.glycines fed on soybean(AgFS)and A.glycines fed on wild soybean(AgFW)were reared at 25℃,27℃,29℃,31... The soybean aphid,Aphis glycines Matsumura,is an important pest of soybean,which is native to Asia.In this study,A.glycines fed on soybean(AgFS)and A.glycines fed on wild soybean(AgFW)were reared at 25℃,27℃,29℃,31℃,33℃and 35℃,respectively,and some of the life parameters were determined.At temperature ranging from 25℃to 31℃,nymphs of AgFS and AgFW all developed into adults successfully.Only a few nymphs of AgFS and AgFW developed into adults at 33℃and no nymphs could develop into adults at 35℃.Lifespan,fecundity and body size of AgFS and AgFW adults all decreased gradually with temperatures increasing from 25℃to 33℃.At 25℃,the intrinsic rate of increase of AgFS was as big as that at 27℃,which was smaller than that at 29℃,but was bigger than that at 31℃.Intrinsic rate of increase of AgFW decreased gradually with temperatures increasing from 25℃to 31℃.Nymph stage duration of AgFW was longer than or as long as that of AgFS;adult lifespan of AgFW was shorter than or as long as that of AgFS.Adult fecundity,intrinsic rate of increase and adult body size of AgFW were all smaller than or as big as those of AgFS.It showed that AgFS and AgFW both survived and developed well at temperature ranging from 25℃to 31℃,and AgFW was more adaptive to low temperatures.These results were important to study the adaptability of A.glycines to high temperatures and for predicting its dynamics in the temperature keeping rising region. 展开更多
关键词 Aphis glycines Matsumura DEVELOPMENT REPRODUCTION high temperature
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Influence of two distinct quenching end-temperatures on phase development and mechanical properties in QP980 steel
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作者 XIE Shuang ZHONG Yong WANG Li 《Baosteel Technical Research》 CAS 2023年第1期22-31,共10页
Bainite microstructures have become increasingly attractive for the development of advanced high-strength steel owing to their balanced strength-plasticity properties.In this study, the final microstructure and mechan... Bainite microstructures have become increasingly attractive for the development of advanced high-strength steel owing to their balanced strength-plasticity properties.In this study, the final microstructure and mechanical properties of a quenching and partitioning(QP) steel sample after two distinct QP processes were analyzed.The results reveal that martensite transformation after quenching resulted in a lathed morphology with higher yield strength and hole expansion ratio.In contrast, bainite transformation after quenching resulted in the formation of a blocky microstructure composed of bainitic ferrite retained austenite and nanoscale precipitates during the subsequent phase transformation at a higher temperature.This kind of final microstructure is beneficial to the elongation of QP steel but detrimental to the hole expansion ratio. 展开更多
关键词 QP steel BAINITE hole expansion quenching temperature
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Hydrogen production at intermediate temperatures with proton conducting ceramic cells:Electrocatalytic activity,durability and energy efficiency
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作者 Haoyu Zheng Feng Han +1 位作者 Noriko Sata Rémi Costa 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期437-446,I0010,共11页
Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatur... Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatures by proton conducting ceramic cell electrolysis(PCCEL).We demonstrate a highperformance steam electrolysis owing to a composite positrode based on BaGd_(0.8)La_(0.2)Co_(2)O_(6-δ)(BGLC1082)and BaZr0.5Ce0.4Y0.1O3-δ(BZCY541).The high reliability of PCCEL is demonstrated for 1680 h at a current density as high as-0.8 A cm^(-2)close to the thermoneutral cell voltage at 600℃.The electrolysis cell showed a specific energy consumption ranging from 54 to 66 kW h kg^(-1)that is comparable to state-of-the-art low temperature electrolysis technologies,while showing hydrogen production rates systematically higher than commercial solid oxide ceramic cells(SOCs).Compared to SOCs,the results verified the higher performances of PCCs at the relevant operating temperatures,due to the lower activation energy for proton transfer comparing with oxygen ion conduction.However,because of the p-type electronic conduction in protonic ceramics,the energy conversion rate of PCCs is relatively lower in steam electrolysis.The faradaic efficiency of the PCC in electrolysis mode can be increased at lower operating temperatures and in endothermic conditions,making PCCEL a technology of choice to valorize high temperature waste heat from industrial processes into hydrogen.To increase the faradaic efficiency by optimizing the materials,the cell design,or the operating strategy is a key challenge to address for future developments of PCCEL in order to achieve even more superior techno-economic merits. 展开更多
关键词 Steam electrolysis Hydrogen production Proton conducting ceramics Intermediate temperature Energy efficiency
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Microstructural characteristics and low-cycle fatigue properties of AZ91 and AZ91-Ca-Y alloys extruded at different temperatures
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作者 Ye Jin Kim Young Min Kim +2 位作者 Jun Ho Bae Soo-Hyun Joo Sung Hyuk Park 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第3期892-902,共11页
The commercial AZ91 alloy and nonflammable SEN9(AZ91-0.3Ca-0.2Y,wt%)alloy are extruded at 300°C and 400°C.Their microstructure,tensile and compressive properties,and low-cycle fatigue(LCF)properties are inve... The commercial AZ91 alloy and nonflammable SEN9(AZ91-0.3Ca-0.2Y,wt%)alloy are extruded at 300°C and 400°C.Their microstructure,tensile and compressive properties,and low-cycle fatigue(LCF)properties are investigated,with particular focus on the influence of the extrusion temperature.In the AZ91 and SEN9 materials extruded at 300°C(300-materials),numerous fine Mg_(17)Al_(12)particles are inhomogeneously distributed owing to localized dynamic precipitation during extrusion,unlike those extruded at 400°C(400-materials).These fine particles suppress the coarsening of recrystallized grains,decreasing the average grain size of 300-materials.Although the four extruded materials have considerably different microstructures,the difference in their tensile yield strengths is insignificant because strong grain-boundary hardening and precipitation hardening effects in 300-materials are offset almost completely by a strong texture hardening effect in 400-materials.However,owing to their finer grains and weaker texture,300-materials have higher compressive yield strengths than400-materials.During the LCF tests,{10-12}twinning is activated at lower stresses in 400-materials than in 300-materials.Because the fatigue damage accumulated per cycle is smaller in 400-materials,they have longer fatigue lives than those of 300-materials.A fatigue life prediction model for the investigated materials is established on the basis of the relationship between the total strain energy density(ΔW_(t))and the number of cycles to fatigue failure(N_(f)),and it is expressed through a simple equation(ΔW_(t)=10·N_(f)-0.59).This model enables fatigue life prediction of both the investigated alloys regardless of the extrusion temperature and strain amplitude. 展开更多
关键词 AZ91-Ca-Y Extrusion temperature MICROSTRUCTURE Low-cycle fatigue Fatigue life prediction model
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Quasi-static and low-velocity impact mechanical behaviors of entangled porous metallic wire material under different temperatures
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作者 Yi-wan Wu Hu Cheng +3 位作者 Shang-zhou Li Yu Tang Hong-bai Bai Chun-hong Lu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第1期143-152,共10页
To improve the defense capability of military equipment under extreme conditions,impact-resistant and high-energy-consuming materials have to be developed.The damping characteristic of entangled porous metallic wire m... To improve the defense capability of military equipment under extreme conditions,impact-resistant and high-energy-consuming materials have to be developed.The damping characteristic of entangled porous metallic wire materials(EPMWM)for vibration isolation was previously investigated.In this paper,a study focusing on the impact-resistance of EPMWM with the consideration of ambient temperature is presented.The quasi-static and low-velocity impact mechanical behavior of EPMWM under different temperatures(25℃-300℃)are systematically studied.The results of the static compression test show that the damping energy dissipation of EPMWM increases with temperature while the nonlinear damping characteristics are gradually enhanced.During the impact experiments,the impact energy loss rate of EPMWM was between 65%and 85%,while the temperatures increased from 25℃to 300℃.Moreover,under the same drop impact conditions,the overall deformation of EPMWM decreases in the temperature range of 100℃-200℃.On the other hand,the impact stiffness,energy dissipation,and impact loss factor of EPMWM significantly increase with temperature.This can be attributed to an increase in temperature,which changes the thermal expansion coefficient and contact state of the internal wire helixes.Consequently,the energy dissipation mode(dry friction,air damping,and plastic deformation)of EPMWM is also altered.Therefore,the EPMWM may act as a potential candidate material for superior energy absorption applications. 展开更多
关键词 Entangled porous metallic wire material Low-velocity impact High temperature Energy dissipation characteristics Mechanical behavior
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Improving tree health assessment accuracy at low temperatures:considering the effect of trunk ice content on electrical resistance and stress wave tomography
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作者 Jiaxing Guo Peng Wang +1 位作者 Yuting Wang Huadong Xu 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第5期1503-1510,共8页
Accurate decay detection and health assessment of trees at low temperatures is an important issue for forest management and ecology in cold areas.Low temperature ice formation on tree health assessment is unknown.Beca... Accurate decay detection and health assessment of trees at low temperatures is an important issue for forest management and ecology in cold areas.Low temperature ice formation on tree health assessment is unknown.Because electric resistance tomography and stress wave tomography are two widely used methods for the detection of tree decay,this study investigated the effect of ice content on trunk electrical resistance and stress wave velocity to improve tree health assessment accuracy.Moisture content,trunk electrical resistance and stress wave velocity using time domain reflectometry were carried out on Larix gmelinii and Populus simonii.Ice content is based on moisture content data.The ice content of both species showed a trend of increasing and then decreasing.This was opposite with ambient temperatures.With the decrease of temperatures,daily average ice content increased,but the range narrowed gradually and both electrical resistance and stress wave velocity increased.Both increased rapidly near 0℃,mainly caused by ice formation(phase change and freezing of free water)in live trees.In addition,both are positively correlated with ice content.The results suggest that ice content should be considered for improving the accuracy of tree decay detection and health evaluation using electric resistance tomography and stress wave velocity methods under low temperatures. 展开更多
关键词 Cross-section electrical resistance Cross-section stress wave velocity Ambient temperatures Ice content Wood decay detection Tree heath
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The mechanism of inward and outward expansion of multiscale dynamic permeability of coalbed methane at different temperatures
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作者 Zhiqiang Li Xiaoqiang Hao +1 位作者 Yanwei Liu Lin Li 《Deep Underground Science and Engineering》 2023年第1期88-101,共14页
The multiscale micro-nano pores in coal can result in the ultra-low permeability of coal,which restricts the efficiency of gas extraction.It is difficult for the conventional seepage-enhancement measures to affect the... The multiscale micro-nano pores in coal can result in the ultra-low permeability of coal,which restricts the efficiency of gas extraction.It is difficult for the conventional seepage-enhancement measures to affect the nanoscale pores within the coal matrix.Thermal stimulation can reach deep into the micro-nano pores within coal matrix to improve the permeability.Therefore,it is important to study the diffusivity and permeability of the multiscale micro-nano pores at different temperatures.In this study,the experiments of diffusion-seepage measured by the methods of GRI(Gas Research Institution)and steady-state were conducted using a cylindrical coal at different temperatures and pressures.The experimental results show that the apparent diffusion coefficient of cylindrical coal is not constant but variable dynamically;and the classical diffusion model fails to describe the full-time process of gas flow accurately.On this basis,a model of multiscale dynamic apparent diffusion-seepage that can accurately describe the full-time flow process was proposed.As is observed,the apparent permeability attenuates dynamically with time without stress loading,and the initial apparent permeability and the attenuation coefficient increase monotonically with the rise of temperature.Under the stress constraint,the steady-state permeability increases after a decrease as the temperature rises,displaying a“U-shaped”pattern.Without stress constraint,the increasing temperature causes the exterior multiscale pores to expand outward by different degrees so as to increase permeability,while the interior micro-nano pores show three inward and outward expansion mechanisms.Under stress constraint,at low temperature and high effective stress,the increasing temperature causes pores to expand inward and the permeability decreases accordingly.When temperature continues to increase,coal expands outward because the effective stress is counteracted by the thermal stress,leading to an increase in permeability.This study is of significance for thermal gas extraction engineering. 展开更多
关键词 DIFFUSION dynamic GAS PERMEABILITY SEEPAGE temperature
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Experimental Study of the Evolution of Temperatures in Pavement Structures and Influence of Traffic on the RN1 in Burkina Faso in a Hot and Dry Climate
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作者 Paul Ilboudo Boubacar Soro +4 位作者 Dieudonné Dabilgou Boureima Kaboré Jean Marie Compaoré Sié Kam Dieudonné Joseph Bathiebo 《Open Journal of Civil Engineering》 2023年第2期303-316,共14页
Asphalt concrete pavements in hot and dry climates deteriorate prematurely some time after their construction. This degradation is accelerated under the effect of heavy vehicle traffic pressure and high temperatures a... Asphalt concrete pavements in hot and dry climates deteriorate prematurely some time after their construction. This degradation is accelerated under the effect of heavy vehicle traffic pressure and high temperatures after the bitumen has softened. A study was conducted on the RN1 in Burkina Faso in order to analyze the evolution of temperature and traffic in the process of degradation of asphalt concrete pavements. It consisted on the one hand in recording the temperatures at different points inside the layers of asphalt concrete pavements and the layer of laterite. These results were compared with the values of the softening temperatures of the bitumen obtained in the laboratory. On the other hand, this study is supplemented by the daily counting of heavy goods vehicles passing through the RN1 during the month of April in order to study the influence of the evolution of heavy goods vehicle traffic on the degradation of pavements in hot and dry climatic conditions. The results obtained for temperatures and the frequency of heavy goods vehicle traffic favor pavement deterioration under certain conditions. 展开更多
关键词 temperature PAVEMENT TRAFFIC CLIMATE Bituminous Concrete
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