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Enhanced pitting resistance for high-entropy alloys by precipitating nano-size d L12-strengthene d phase
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作者 Tianrun Li Debin Wang +3 位作者 Jingping Cui Qi Wang Suode Zhang Jianqiang Wang 《Journal of Materials Science & Technology》 2025年第5期53-66,共14页
Precipitation-strengthened HEAs exhibit outstanding integration of strength and toughness at ambient temperature.Nevertheless,precipitates generally reduce the localized corrosion resistance in aggressive solution env... Precipitation-strengthened HEAs exhibit outstanding integration of strength and toughness at ambient temperature.Nevertheless,precipitates generally reduce the localized corrosion resistance in aggressive solution environments.To solve this problem,a strategy of introducing nano-sized L12 precipitates in CoCrFeNiAlTi HEAs has been proposed in this work.Results demonstrate the pitting corrosion potential can be elevated from 258 mVSCE to 603 mVSCE by increasing the precipitate content to 38 wt.%.Such an improvement in localized corrosion resistance can be attributed to two aspects.Firstly,L12 precipitates tend to be dissolved during the corrosion process,which promotes the heterogeneous nucleation of protective Cr2 O3 due to the rapid deposition of oxides/hydroxides of Al/Ti,and improves the passive film stability due to the Crrich FCC matrix.Secondly,the dissolution kinetic inside the pits can be suppressed on account of the enrichment of Cr element in the FCC matrix,thus inhibiting the pitting growth.In summary,the current work not only reveals the mechanisms of the nano-sized L12 precipitates upon the corrosion behavior,but also provides a strategy for designing corrosion-resistant HEA. 展开更多
关键词 High entropy alloys PRECIPITATION Passive films Pitting corrosion
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Precipitating thermally reinforcement phase in aluminum alloys for enhanced strength at 400℃ 被引量:2
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作者 Xiang Su Yuan Lei +6 位作者 Yang Chen Hongjie Qu Zhixiang Qi Gong Zheng Xu Liu Henggao Xiang Guang Chen 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第5期71-82,共12页
Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy conservation.However,the high-temperature str... Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy conservation.However,the high-temperature strength of existing cast aluminum alloys is always limited to about 100 MPa at 350℃due to coarsening and transformation of strengthening phases.Here,we reveal that the yield strength and ultimate tensile strength of the T6 state Al-8.4Cu-2.3Ce-1.0Mn-0.5Ni-0.2Zr alloy at 400◦C increase by 34%and 44%after re-aging at 300℃for 100 h,and its thermal strength exhibits distinguished ad-vantage over traditional heat-resistant aluminum alloys.The enhanced elevated-temperature strength is attributed to the reprecipitation of the Ni-bearing T-Al_(20)Cu_(2)Mn_(3)phase,whose number density increases over one time.The significant segregation of Ni,Ce,and Zr elements at the interfaces helps improve the thermal stability of the T phase.The thermostable T phase effectively strengthens the matrix by in-hibiting dislocation motion.Meanwhile,a highly interconnected 3D intermetallic network along the grain boundaries can still remain after long-term re-aging at 300℃,which is conducive to imposing a drag on the grain boundaries at high temperatures.This finding offers a viable route for enhancing the elevated-temperature strength of heat-resistant aluminum alloys,which could provide expanded opportunities for higher-temperature applications. 展开更多
关键词 Aluminum alloys PRECIPITATION Thermally reinforcement phase Re-aging treatment High-temperature strength
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Ge and Cu recovery from precipitating vitriol supernatant in zinc plant 被引量:3
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作者 周兆安 楚广 +2 位作者 甘红祥 杨天足 陈霖 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第5期1506-1511,共6页
A novel technology using Fe powder as reducing agent for Ge and Cu recovery from precipitating vitriol supernatant in Zn hydrometallurgical plant was investigated. The results show that reaction time, temperature, agi... A novel technology using Fe powder as reducing agent for Ge and Cu recovery from precipitating vitriol supernatant in Zn hydrometallurgical plant was investigated. The results show that reaction time, temperature, agitation speed, initial pH value of solution and the amount of reducing Fe have significant effects on recovering Ge and Cu, and the optimum process operating parameters are established as follows: time 120 min, initial pH value 1.5, the dosage of reducing Fe powder 4 g/L, agitation speed 600 r/min and temperature 80 °C. Under these experimental conditions, the recovery ratios of Ge and Cu from precipitating vitriol supernatant in Zn hydrometallurgical plant can reach 96% and 100%, respectively. The content of Ge in the reduced residue reaches up to 2.06% (mass fraction), indicating that the separation and enrichment of Ge from the Zn sulfate solution is realized. The grade of Ge and Cu can reach up to 4.88% and 56.75%, respectively, when the reduced residue is further processed. 展开更多
关键词 RECOVERY Ge CU zinc hydrometallurgy precipitating vitriol supernatant CEMENTATION Fe powder
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Influence of the Precipitating Reagents and Dispersants on the Formation Nano-Aluminum Hydroxide 被引量:1
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作者 G. Sarsenbay L. A. Myltykbaeva +1 位作者 R. A. Abdulwalyev B. M. Sukurov 《Journal of Materials Science and Chemical Engineering》 2013年第5期11-15,共5页
The influence of the precipitating reagents and dispersants on the formation of nano-aluminum hydroxide from sodium aluminate solution by chemical precipitation was investigated. The influence of the dispersed seeds o... The influence of the precipitating reagents and dispersants on the formation of nano-aluminum hydroxide from sodium aluminate solution by chemical precipitation was investigated. The influence of the dispersed seeds on the decomposi-tion process was investigated too. The alkaline aluminate solutions were used as original solutions with a concentration of Al2O3 having 14.78 g/dm3, αk—1.6 and127 g/dm3, αk—1.6. For the precipitation processes there were used follow-ing precipitating reagents—solutions HCl, NaHCO3 and NH4HCO3 with a concentration of 80 g/dm3, dispersants—PEG 6000, (NaPO3)6 and Tween 20. For the decomposition process the dispersed seeds and factories seeds were used. Structural studies of the aluminum hydroxide particles were carried out by means of the electron-probe microanalysis and scanning electron microscopy, and phase composition of products was determined by means of X-ray diffraction analysis. Ammonium bicarbonate and Tween 20 were determined as the optimal precipitating reagent and dispersant, correspondingly, resulting in dispersed aluminum hydroxide, which is used as a seed in the decomposition process. It was established that this product in form of dispersed seed considerably reduces the duration of the decomposition process;the maximal decomposition of solution (73.9%) was observed after injection of dispersеd aluminum hydroxide into solution. The final aluminum hydroxide having 90% of particles less than 100 nanometers was obtained within 7 hours of steady decreasing temperature from 70°C to 48°C. 展开更多
关键词 Nano-Aluminum HYDROXIDE precipitating REAGENTS DISPERSANTS Alkaline ALUMINATE Solution Precipitation Particles Decomposition Particle Diameter
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A simulation study of the influence of soft precipitatingelectrons on the polar ionosphere 被引量:1
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作者 张北辰 刘瑞源 +1 位作者 刘顺林 贺龙松 《Chinese Journal of Polar Science》 1999年第2期117-124,共8页
Calculation of the influence of soft precipitating electrons on the polar ionosphere was carried out. The primary results are: (1) During summer time when the sunlight is the main source of upper atmosphere ionization... Calculation of the influence of soft precipitating electrons on the polar ionosphere was carried out. The primary results are: (1) During summer time when the sunlight is the main source of upper atmosphere ionization, the additional soft electron precipitation can increase the NmF2. The daily variation of NmF2 is mainly controlled by solar EUV radiation. (2) At wintertime, when only soft electron precipitation ionization is considered, a peak at the height of F2 layer also appears. The altitude profile of electron density is different frorn that when the sunlit ionization is taken into account. 展开更多
关键词 IONOSPHERE SIMULATION soft precipitating electron
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Preparation and morphology of nano-size ceria by a stripping precipitation using oxalic acid as a precipitating agent 被引量:2
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作者 梅燕 王为 +1 位作者 孙何 聂祚仁 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第12期1265-1269,共5页
The precursors organic cerium deposits were obtained by a stripping precipitation method from cerium-loaded P507 organic phase using oxalic acid as a precipitating agent and nano-sized ceria particles were prepared by... The precursors organic cerium deposits were obtained by a stripping precipitation method from cerium-loaded P507 organic phase using oxalic acid as a precipitating agent and nano-sized ceria particles were prepared by calcining the precursors at 500 ℃. The morphologies, phase structure of the precursors and ceria particles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TG-DSC) and infrared spectroscopy analysis (FTIR). The results indicated that the concentration of oxalic acid had a little impact on the morphology of the precursors, which was blocky-shape Ce2(C2O4)3:10H2O with a monoclinic lattice structure. With the volume ratio of organic phase and oxalic acid aqueous solution (aqueous phase) varied from 1:3 to 1:6, the morphologies of the precursors Ce2(C2O4)3· 10H2O precipitates gradually changed from inhomogeneous blocky-shape to uniform spherical particles. The precursors could be turned to CeO2 crystal particles with a fluorite structure by calcining, and the products ceria particles were similar in the size and morphology to the precursors. 展开更多
关键词 MORPHOLOGY stripping method PRECIPITATE rare earths
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Precipitating Mechanism of Carbide in Cold-Welding Surfacing Metals 被引量:1
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作者 YuanbinZHANG DengyiREN 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第6期766-768,共3页
Carbides in a series of cold-welding weld metals were studied by means of SEM, TEM and EPMA, and the forming mechanism of carbide was proposed according to their distribution and morphology. Due to their different car... Carbides in a series of cold-welding weld metals were studied by means of SEM, TEM and EPMA, and the forming mechanism of carbide was proposed according to their distribution and morphology. Due to their different carbide-forming tendency, Nb and Ti could combine with C to form particulate carbide in liquid weld metai and depleted the carbon content in matrix, while V induced the carbide precipitated along grain boundary. But too much Nb or Ti alone resulted in coarse carbide and poor strengthened matrix. When suitabie amount of Nb, Ti and V coexisted in weld metai, both uniformly distributed particulate carbide and well strengthened matrix could be achieved. It was proposed that the carbide nucleated on the oxlde which dispersed in liquid weld metai, and then grew into multi-layer complex carbide particies by epitaxial grovvth. At different sites, carbide particies may present as different morphologies. 展开更多
关键词 Cold-welding CARBIDE Weld metai PRECIPITATE
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Influence of Heat Treatment on Cr18Mn18 High Nitrogen Steel Precipitating Behavior and Microstructure
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作者 Li Jingyuan, Feng Shufei, Fang Fei, Chen Yulai University of Science and Technology Beijing, Beijing 100083,China 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2011年第S3期111-113,共3页
The grain size and precipitate amount which are affected by heat treatment have significant impact on the properties of high nitrogen austenitic stainless steel. In this study, Cr18Mn18 high nitrogen steel sheet is em... The grain size and precipitate amount which are affected by heat treatment have significant impact on the properties of high nitrogen austenitic stainless steel. In this study, Cr18Mn18 high nitrogen steel sheet is employed to investigate the effects of precipitate on austenitic grain size. It can be seen that the lamella precipitates which are rich in nitrogen and chromium nucleate in the austenite grain boundary and grow inward into grain when aged at 800 ℃ through electron probe micro-analyzer. The transmission electron microscopy results demonstrate that the precipitate is Cr2N and its morphology are detected as ellipsoid-like with major axis of 100-300 nm and minor axis of 50-100 nm roughly. The experiment show that coarsen of the austenite grain is quite critical at 1000-1100 ℃. However, the samples which pre-precipitated at 800 ℃ for 240 min to obtain the most nitride precipitate exhibits much smaller grain size than the as-rolled samples after solid solution treated at 1000, 1050 and 1100 ℃ for 240 min. The results show that the nitride precipitates in the grain boundary can effectively pin the austenite grain boundary and inhibit the grain growth. 展开更多
关键词 high nitrogen AUSTENITIC STAINLESS steel heat treatment PRECIPITATE MICROSTRUCTURE
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Effect of Precipitating Phases on Tensile Strength and Microstructural Stability of a Spray-Deposited Al-Si-Fe-Mn-Cu-Mg Alloy
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作者 FengWANG YuanshengJIN +1 位作者 DunyuanHU JishanZHANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第1期78-80,共3页
Spray deposition is a novel process which is used to manufacture rapidly solidified bulk and near-net-shape preforms. In this study, AI-20Si-5Fe-3Mn-3Cu-1Mg alloy was synthesized by spray deposition technique. The agi... Spray deposition is a novel process which is used to manufacture rapidly solidified bulk and near-net-shape preforms. In this study, AI-20Si-5Fe-3Mn-3Cu-1Mg alloy was synthesized by spray deposition technique. The aging process of the alloy was investigated by differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM). The results show that two kinds of phases, i.e. S(Al2CuMg) and σ(Al5Cu6Mg2), precipitate from matrix and improve the tensile strength of the alloy efficiently at both the ambient and elevated temperatures (300℃). In addition, the σ-Al5Cu6Mg2 is a relatively stable phase which improves microstructural stability of the alloy. 展开更多
关键词 Spray deposition PRECIPITATE Tensile strength Microstructural stability
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Effects of low-temperature tempering on the microstructure and precipitating evolution of newly developed high-strength microalloyed steel
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作者 WANG Huanrong WANG Wei ZHANG Zuogui 《Baosteel Technical Research》 CAS 2009年第3期58-64,共7页
The effect of tempering temperature on the microstrocture and precipitating evolution and the resultant mechanical properties of newly developed high-strength microalloyed steel plate was investigated by optical micro... The effect of tempering temperature on the microstrocture and precipitating evolution and the resultant mechanical properties of newly developed high-strength microalloyed steel plate was investigated by optical microscopy (OM) and transmission electron microscopy (TEM). The steel mainly consists of fine lath martensite and lower bainite. The width of the martensitic laths in as-hot-rolled state is about 120 nm,and increases from 120 nm to 150 nm and 180 nm after tempering at 200 ℃ and 250℃ for 2 h respectively with no change in its morphology. Of special interest is the phenomenon that both tensile strength and impact toughness of the steel plate decrease with the increase of the tempering temperature, which might be attributed to the combination of lath martensite broadening and the coarsening of needle-like carbides located on the boundaries of lath martensite and within bainitic ferrite. It is suggested that the existence of the complex carbonitride larger than 100 nm in bainitic ferrite is one of the reasons. 展开更多
关键词 TEMPERING MICROSTRUCTURE PRECIPITATE mechanical property microalloyed steel
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CAS-ESM2.0 Dataset for the G1ext Experiment of the Geoengineering Model Intercomparison Project(GeoMIP) 被引量:2
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作者 Min CUI Duoying JI +8 位作者 John CMOORE He ZHANG Jiangbo JIN Kece FEI Chenglai WU Jiawen ZHU Juanxiong HE Zhaoyang CHAI Dongling ZHANG 《Advances in Atmospheric Sciences》 2025年第3期579-592,共14页
Solar radiation modification,a scheme aimed at mitigating rapid global warming triggered by anthropogenic greenhouse gas emissions,has been explored through the G1ext experiment under the Geoengineering Model Intercom... Solar radiation modification,a scheme aimed at mitigating rapid global warming triggered by anthropogenic greenhouse gas emissions,has been explored through the G1ext experiment under the Geoengineering Model Intercomparison Project(GeoMIP) framework,utilizing the Chinese Academy of Sciences Earth System Model version 2(CAS-ESM2.0).This paper briefly describes the basic configuration and experimental design of the CAS-ESM2.0 for G1ext,which involves a sudden reduction in solar irradiance to counterbalance the radiative forcing of an abrupt quadrupling of atmospheric CO_(2) concentration,running for 100 years.Preliminary results show that this model can reproduce well the compensatory effect of a uniform decrease in global solar radiation on the radiative forcing resulting from an abrupt quadrupling of CO_(2) concentration.Like other Earth system models,CAS-ESM2.0 reasonably captures variations in radiative adjustments,surface air temperature,and precipitation patterns,both globally and locally,under the G1ext scenario.The generated datasets have been released on the Earth System Grid Federation data server,providing insight into the potential efficacy and impact of solar geoengineering strategies. 展开更多
关键词 CAS-ESM2.0 GeoMIP GEOENGINEERING radiative adjustment temperature PRECIPITATION
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Improving the Seasonal Forecast of Summer Precipitation in Southeastern China Using a CycleGAN-based Deep Learning Bias Correction Method 被引量:1
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作者 Song YANG Fenghua LING +1 位作者 Jing-Jia LUO Lei BAI 《Advances in Atmospheric Sciences》 2025年第1期26-35,共10页
Accurate seasonal precipitation forecasts,especially for extreme events,are crucial to preventing meteorological hazards and their potential impacts on national development,social activity,and security.However,the int... Accurate seasonal precipitation forecasts,especially for extreme events,are crucial to preventing meteorological hazards and their potential impacts on national development,social activity,and security.However,the intensity of summer precipitation is often largely underestimated in many current dynamic models.This study uses a deep learning method called Cycle-Consistent Generative Adversarial Networks(CycleGAN)to improve the seasonal forecasts for June-JulyAugust precipitation in southeastern China by the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS 1.0).The results suggest that the CycleGAN-based model significantly improves the accuracy in predicting the spatiotemporal distribution of summer precipitation compared to the traditional quantile mapping(QM)method.Using the unpaired bias-correction model,we can also obtain advanced forecasts of the frequency,intensity,and duration of extreme precipitation events over the dynamic model predictions.This study expands the potential applications of deep learning models toward improving seasonal precipitation forecasts. 展开更多
关键词 bias correction CycleGAN QM NUIST-CFS 1.0 extreme precipitation
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Atomic-scale investigation on the evolution of T_(1) precipitates in an aged Al-Cu-Li-Mg-Ag alloy 被引量:1
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作者 Xinyue Zhao Juan Ding +2 位作者 Daihong Xiao Lanping Huang Wensheng Liu 《Journal of Materials Science & Technology》 2025年第6期139-148,共10页
The T_(1)(Al_(2) CuLi)phase is one of the most effective strengthening nanoscale-precipitate in Al-Cu alloys with Li.However,its formation and evolution still need to be further clarified during aging due to the compl... The T_(1)(Al_(2) CuLi)phase is one of the most effective strengthening nanoscale-precipitate in Al-Cu alloys with Li.However,its formation and evolution still need to be further clarified during aging due to the complex precipitation sequences.Here,a detailed investigation has been carried out on the atomic struc-tural evolution of T_(1) precipitate in an aged Al-Cu-Li-Mg-Ag alloy using state-of-the-art Cs-corrected high-angle annular dark field(HAADF)-coupled with integrated differential phase contrast(iDPC)-scanning transmission electron microscopy(STEM)and energy-dispersive X-ray spectroscopy(EDXS)techniques.An intermediate T_(1)’phase between T_(1p) and T_(1) phase,with a crystal structure and orientation rela-tionship consistent with T_(1),but exhibiting different atomic occupancy and chemical composition was found.We observed the atomic structural transformation from T_(1p) to T_(1)’phase(fcc→hcp),involving only 1/12<112>Al shear component.DFT calculation results validated our proposed structural models and the precipitation sequence.Besides,the distributions of minor solute elements(Ag,Mg,and Zn)in the pre-cipitates exhibited significant differences.These findings may contribute to a further understanding of the nucleation mechanism of T_(1) precipitate. 展开更多
关键词 PRECIPITATE Chemical composition Atomic structure Aluminium alloy STEM
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Aging response and mechanism of dual-phase Mg-Li-Al-Zn alloy 被引量:1
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作者 Yuchuan Huang Jiawei Sun +3 位作者 Fangzhou Qi Youjie Guo Guohua Wu Wencai Liu 《Journal of Magnesium and Alloys》 2025年第4期1646-1659,共14页
In this work,the aging response and mechanism of dual-phase Mg-Li-Al-Zn alloy at various temperatures are investigated.The results show that the strengthening after quenching is primarily attributed to the immediate p... In this work,the aging response and mechanism of dual-phase Mg-Li-Al-Zn alloy at various temperatures are investigated.The results show that the strengthening after quenching is primarily attributed to the immediate precipitation of the semi-coherent~Mg_(3)Zn phase.The aging softening of the studied alloy is mainly caused by the rapid transformation of the strengthening~Mg_(3)Zn phase to the softening MgLi(Al,Zn)phase,along with the coarsening of theα-Mg matrix and precipitates withinβ-Li matrix.Further analysis indicates that the quick precipitation and transformation of~Mg_(3)Zn is a consequence of the high diffusion rate of solute atoms,resulting from dense vacancy concentration in theβ-Li matrix.This research bridges a critical gap in the study of aging mechanism in the dual-phase Mg-Li-Al-Zn alloy,providing a theoretical basis for the development and application of high-performance and thermal-stable Mg-Li alloys. 展开更多
关键词 Mg-Li-Al-Zn alloy Aging behavior PRECIPITATE Tensile properties
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Effects of sub-solvus ageing on the tensile and creep properties of a new cast nickel-based superalloy 被引量:1
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作者 Peng-Fei Zhao Kun-Lei Hou +3 位作者 Min Wang Mei-Qiong Ou Ya-qian Yang Ying-Che Ma 《Journal of Materials Science & Technology》 2025年第9期289-302,共14页
For nickel-based superalloys with medium volume-fractionγʹphase(20%-40%),dual or multi-stage aging treatments are usually conducted to generate a microstructure containing the multimodal distri-bution ofγʹfor a bala... For nickel-based superalloys with medium volume-fractionγʹphase(20%-40%),dual or multi-stage aging treatments are usually conducted to generate a microstructure containing the multimodal distri-bution ofγʹfor a balance of strength and plasticity.In the present study,the microstructure and high-temperature properties of a novel cast nickel-based superalloy K4800 were investigated after being sub-jected to three heat treatments(HT)procedures,namely HT1:1180℃/4 h+1090℃/2 h+800℃/16 h,HT2:1180℃/4 h+1060℃/2 h+800℃/16 h and HT3:1180℃/4 h+800℃/16 h.It was found that the sub-solvus aging treatments at 1090 and 1060℃ precipitated sub-micron-sized(∼300 nm)primaryγʹphase which enhanced the ductility during 800℃ tensile(the total elongation of T1,T2,and T3 sam-ples were 6.75%,7.3%,and 3.25%,respectively)without evidently impairing the strength.After careful microstructure observation and deformation mechanism analysis,the enhancement of elongation was ra-tionalized that the precipitation of the sub-micron-sized primaryγʹphase decreased the volume-fraction and size of the nanometer-sizedγʹphase which was precipitated at 800℃,and simultaneously,pro-moted the dislocation movement by suppressing the non-planar slip.However,an excessive amount of the sub-micron-sized primaryγʹphase led to a faster ripening process of the nanometer-sizedγʹduring creep,which decreased the creep life at 800℃/430 MPa(T1:125 h,T2:199 h,and T3:198 h).Based on this,we monitored the number density of nanometer-sizedγʹphase coexisting with different amounts of largeγʹduring creep.An area fraction less than 7%of the sub-micron-sizedγʹphase was considered to have little detrimental effect on the creep life of K4800 alloy,which corresponded to a sub-solvus temperature range about 1080-1090℃. 展开更多
关键词 Nickel-base superalloy Heat treatment Mechanical property Precipitation strengthening Deformation mechanism
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Water–Heat Synergy Shapes Evapotranspiration–Precipitation Coupling Patterns across Northern China 被引量:1
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作者 Zesu YANG Qiang ZHANG +4 位作者 Yu ZHANG Ping YUE Jian ZENG Lixia MENG Yulei QI 《Advances in Atmospheric Sciences》 2025年第6期1167-1178,共12页
Northern China is a prominent “hotspot” for land–atmosphere interactions, with substantial gradients in both moisture and thermal conditions. Previous studies have identified a link between land–atmosphere couplin... Northern China is a prominent “hotspot” for land–atmosphere interactions, with substantial gradients in both moisture and thermal conditions. Previous studies have identified a link between land–atmosphere coupling and the individual roles of each factor, but the synergistic effect of the two factors remains unclear. This study considers the covariation of evapotranspiration and precipitation to assess evapotranspiration–precipitation(ET–P) coupling across northern China,exploring its spatial variations and their linkage to water and heat factors. Our findings reveal a transition from strongly positive coupling in the northwest to weakly negative coupling in the southeast, peaking in spring. These spatial variations are attributable to water(soil moisture) and heat(air temperature), which explain 39% and 25% of the variability,respectively. The aridity index(AI), a water–heat synergy factor, is the dominant factor, explaining 66% of the spatial variation in ET–P coupling. As the AI increases, ET–P coupling shifts from strongly positive to weakly negative, with an AI around 0.7. This shift is determined by a shift in the evapotranspiration–lifting condensation level(LCL) coupling under an AI change. Regions with an AI below 0.7 experience water-limited evapotranspiration, where increased soil moisture enhances evapotranspiration, reduces sensible heat(H), and lowers the LCL, resulting in a negative ET–LCL coupling.Conversely, regions with an AI above 0.7 experience energy-limited evapotranspiration, where the positive ET–LCL coupling reflects a positive H–LCL coupling or a positive impact of the LCL on evapotranspiration. This analysis advances our understanding of the intricate influences of multifactor surface interactions on the spatial variations of land–atmosphere coupling. 展开更多
关键词 land–atmosphere interaction EVAPOTRANSPIRATION PRECIPITATION aridity index climate transition zone
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Effect of cold rolling on aging precipitation and mechanical properties of magnesium-aluminum alloy 被引量:1
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作者 Feiya Liu Renlong Xin +1 位作者 Yiru Zhong Qing Liu 《Journal of Magnesium and Alloys》 2025年第6期2606-2617,共12页
Although magnesium-aluminum alloys,such as AZ80 and AZ91 have promising application potential in automotive,high-speed train and aerospace fields,their age-hardening response is generally not very appreciable.In this ... Although magnesium-aluminum alloys,such as AZ80 and AZ91 have promising application potential in automotive,high-speed train and aerospace fields,their age-hardening response is generally not very appreciable.In this work,the aging-hardening response of AZ80 alloy was effectively enhanced by applying cold-rolling deformation before conducting conventional aging treatment at 200°C.Compared to the directly aged sample,the yield strength of the pre-rolling and aged sample was increased by 35 MPa.Electron microscope examination confirmed that profuse{10¯11}and{10¯11}-{10¯12}twins,consisting of high density of dislocations and stacking faults,were generated by cold rolling.Blocky or ellipsoidal Mg_(17)Al_(12)precipitates formed at the twin boundaries(TBs)during subsequent aging treatment.Crystallographic analysis indicated that the precipitates at{10¯11}TBs always held an identical Potter OR with both the matrix and twin,while the precipitates at{10¯11}-{10¯12}TBs exhibited three different ORs:Burgers OR,Potter OR and P-S OR with either the matrix or the twin.Moreover,recrystallized grains were found inside{10¯11}-{10¯12}double twins after peak-aging at 200°C,implying that precipitation and recrystallization might occur concurrently along TBs at a relatively low temperature.It was speculated that the highly stored energy inside twins and the high elastic energy between the precipitates and twins were driving factors for the occurrence of recrystallization. 展开更多
关键词 Magnesium alloy Cold rolling Aging precipitation Twin boundary Orientation relationship
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Effects of La and Ce on the microstructure,thermal conductivity and strength synergy of the as-extruded Mg-Mn-RE alloys 被引量:1
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作者 Huafeng Liu Taiki Nakata +6 位作者 Chao Xu Guangze Tang Danyang Li Xiaojun Wang Guisong Wang Shigeharu Kamado Lin Geng 《Journal of Magnesium and Alloys》 2025年第2期654-667,共14页
High thermal conductivity and high strength Mg-1.5Mn-2.5Ce alloy with a tensile yield strength of 387.0 MPa,ultimate tensile strength of 395.8 MPa,and thermal conductivity of 142.1 W/(m·K)was successfully fabrica... High thermal conductivity and high strength Mg-1.5Mn-2.5Ce alloy with a tensile yield strength of 387.0 MPa,ultimate tensile strength of 395.8 MPa,and thermal conductivity of 142.1 W/(m·K)was successfully fabricated via hot extrusion.The effects of La and Ce additions on the microstructure,thermal conductivity,and mechanical properties of the Mg-1.5Mn alloy were investigated.The results indicated that both the as-extruded Mg-1.5Mn-2.5La and Mg-1.5Mn-2.5Ce alloys exhibited a bimodal grain structure,with dynamically precipitated nano-scaleα-Mn phases.In comparison with La,the addition of Ce enhanced the dynamic precipitation more effectively during hot extrusion,while its influence on promoting the dynamic recrystallization was relatively weaker.The high tensile strength obtained in the as-extruded Mg-1.5Mn-2.5RE alloys can be attributed to the combined influence of the bimodal grain structure(with fine dynamic recrystallized(DRXed)grain size and high proportion of un-dynamic recrystallized(unDRXed)grains),dense nano-scale precipitates,and broken Mg12RE phases,while the remarkable thermal conductivity was due to the precipitation of Mn-rich phases from the Mg matrix. 展开更多
关键词 Mg-Mn-RE alloys Thermal conductivity Mechanical properties Dynamic precipitation
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Achieving ultrahigh strength and ductility via high-density nanoprecipitates triggering multiple deformation mechanisms in a dual-aging high-entropy alloy with precold deformation 被引量:1
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作者 Liyuan Liu Yang Zhang Zhongwu Zhang 《Journal of Materials Science & Technology》 2025年第2期27-41,共15页
How to achieve high-entropy alloys(HEAs)with ultrahigh strength and ductility is a challenging issue.Precipitation strengthening is one of the methods to significantly enhance strength,but unfortunately,ductility will... How to achieve high-entropy alloys(HEAs)with ultrahigh strength and ductility is a challenging issue.Precipitation strengthening is one of the methods to significantly enhance strength,but unfortunately,ductility will be lost.To overcome the strength-ductility trade-off,the strategy of this study is to induce the formation of high-density nanoprecipitates through dual aging(DA),triggering multiple deformation mechanisms,to obtain HEAs with ultrahigh strength and ductility.First,the effect of precold deformation on precipitation behavior was studied using Ni_(35)(CoFe)_(55)V_(5)Nb_(5)(at.%)HEAas the object.The results reveal that the activation energy of recrystallization is 112.2 kJ/mol.As the precold-deformation amount increases from 15%to 65%,the activation energy of precipitation gradually decreases from 178.8 to 159.7 kJ/mol.The precipitation time shortens,the size of the nanoprecipitate decreases,and the density increases.Subsequently,the thermal treatment parameters were optimized,and the DA process was customized based on the effect of precold deformation on precipitation behavior.High-density L1_(2) nanoprecipitates(~3.21×10^(25) m^(-3))were induced in the 65% precold-deformed HEA,which led to the simultaneous formation of twins and stacking fault(SF)networks during deformation.The yield strength(YS),ultimate tensile strength,and ductility of the DA-HEA are~2.0 GPa,~2.2 GPa,and~12.3%,respectively.Compared with the solid solution HEA,the YS of the DA-HEA increased by 1,657 MPa,possessing an astonishing increase of~440%.The high YS stems from the precipitation strengthening contributed by the L1_(2) nanoprecipitates and the dislocation strengthening contributed by precold deformation.The synergistically enhanced ductility stems from the high strain-hardening ability under the dual support of twinning-induced plasticity and SF-induced plasticity. 展开更多
关键词 High-entropy alloy Precold deformation Precipitation behavior Ultrahigh strength Deformation mechanism
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A Year Marked by Extreme Precipitation and Floods:Weather and Climate Extremes in 2024 被引量:1
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作者 Wenxia ZHANG Tianjun ZHOU +17 位作者 Wanheng YE Tingyu ZHANG Lixia ZHANG Piotr WOLSKI James RISBEY Zhuo WANG Seung-Ki MIN Hamish RAMSAY Michael BRODY Alice GRIMM Robin CLARK Kangnian REN Jie JIANG Xiaolong CHEN Shenming FU Lan LI Shijie TANG Shuai HU 《Advances in Atmospheric Sciences》 2025年第6期1045-1063,共19页
This past year, 2024, is on track to be the warmest year, joining 2023 as the two hottest years on record. With the exceptional heat, weather and climate extremes were common across the world. In particular, 2024 has ... This past year, 2024, is on track to be the warmest year, joining 2023 as the two hottest years on record. With the exceptional heat, weather and climate extremes were common across the world. In particular, 2024 has seen a remarkable run of extreme precipitation events and resulting impacts. Here, we provide an overview of the most notable extreme events of the year, including extreme precipitation and floods, tropical cyclones, and droughts. The characteristics and impacts of these extreme events are summarized, followed by discussion on the physical drivers and the role of global warming.Finally, we also discuss the future prospects in extreme event studies, including impact-based perspectives, challenges in attribution of precipitation extremes, and the existing gap to minimize impacts from climate extremes. 展开更多
关键词 weather and climate extremes extreme precipitation tropical cyclones DROUGHTS
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