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Effect of long-term thermal exposure on microstructure and creep properties of DD5 single crystal superalloy 被引量:3
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作者 Xu-dong Wang Zhong Yang +1 位作者 Qiang Gao Li-rong Liu 《China Foundry》 SCIE CAS 2021年第3期185-191,共7页
The effect of thermal exposure on the microstructure and creep properties of the Ni-based single crystal superalloy in different test conditions was studied.Long-term exposure was performed at 1,000 ℃ and 1,100 ℃ fo... The effect of thermal exposure on the microstructure and creep properties of the Ni-based single crystal superalloy in different test conditions was studied.Long-term exposure was performed at 1,000 ℃ and 1,100 ℃ for 500 h prior to the creep tests.The creep lifetime is found to be improved after the long-term exposure at 1,000 ℃ for 500 h as a result of the formation of secondary M_(23)C_(6) in the interdendritic region.The coarsening of γ’ precipitates accompanied by the formation of TCP phase lead to the degradation of alloy,which is responsible for the reduction of the creep lifetime of Ni-base single crystal superalloy after long-term exposure at 1,100 ℃ for 500 h.The creep lifetime of 1,000 oC thermally exposed sample under the conditions of 1,093 ℃/137 MPa is lower than that of heat-treated state.Thermal exposure at 1,100 ℃ for 500 h causes the creep lifetime to drop drastically. 展开更多
关键词 long-term thermal exposure MICROSTRUCTURE creep properties Ni-based single crystal superalloy M_(23)C_(6)carbide
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Microstructure and mechanical properties of the pressure die cast magnesium alloy AZ91D after long-term thermal exposure
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作者 D. Regener 《China Foundry》 SCIE CAS 2005年第2期77-84,共8页
The thermal resistance of the pressure die cast magnesium alloy AZ91D is yet not investigated sufficiently. Inorder to assess the effect of a thermal exposure on the microstructural stability and the mechanical proper... The thermal resistance of the pressure die cast magnesium alloy AZ91D is yet not investigated sufficiently. Inorder to assess the effect of a thermal exposure on the microstructural stability and the mechanical properties, the alloyAZ91D is subjected to a long-term annealing for 1 000 h at 80 °C, 100 °C, 120 °C, 150 °C, 180 °C and 200 °C. After theannealing, the microstructural appearance of the material is investigated by light and scanning electron microscopy andcompared with the as-cast condition. Furthermore, tensile tests, hardness measurements and fracture toughness tests arecarried out and the measured values are discussed on the basis of the microstructural changes. The results reveal thedistinct correlation between the microstructural changes, especially the precipitation of discontinuous and continuousβ-particles (Mg17 Al12), and the mechanical properties. 展开更多
关键词 magnesium-aluminium alloy AZ91D long-term thermal exposure microstructure metallography tensiletests HARDNESS fracture TOUGHNESS
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Spatial Optimization Strategies for High Temperature Heat Exposure Based on Thermally Vulnerable Populations and Case Studies
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作者 XIA Xiaoya YANG Xin ZHANG Qi 《Journal of Landscape Research》 2024年第2期1-5,14,共6页
The objective of this study is to investigate the factors that contribute to brittleness and to identify strategies for mitigating these factors in populations with varying degrees of thermal vulnerability,based on th... The objective of this study is to investigate the factors that contribute to brittleness and to identify strategies for mitigating these factors in populations with varying degrees of thermal vulnerability,based on the potential impact of extreme heat exposure on human survival and habitability.The physiological condition of lower adaptability to high temperature environments and the assessment of individuals who may have higher tolerance time in high temperature environments based on spatial perspectives suggest the need for targeted spatial optimization strategies for commuters and disadvantaged populations.This is demonstrated through a case study.These optimization measures encompass a variety of aspects,including the integration of transportation systems,the expansion of grey space corridors,the improvement of green space layout,and the implantation of green infrastructure.The study aims to reduce the exposure time of thermally vulnerable individuals to high temperature environments through spatial optimization strategies,to enhance the resilience of urban green spaces to heat stress,and to reduce the probability of heat-wave occurrence. 展开更多
关键词 thermal vulnerability exposure High temperature environment Spatial optimization
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Microstructural evolution and its influence on the impact toughness of GH984G alloy during long-term thermal exposure 被引量:2
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作者 Yunsheng Wu Xuezhi Qin +1 位作者 Changshuai Wang Lanzhang Zhou 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第1期61-69,共9页
The microstructure evolution and its effect on the impact toughness of a new Ni-Fe based alloy GH984 G,used in 700℃ ultra-super critical coal-fired power plant,were investigated during thermal exposure at 650℃-750℃... The microstructure evolution and its effect on the impact toughness of a new Ni-Fe based alloy GH984 G,used in 700℃ ultra-super critical coal-fired power plant,were investigated during thermal exposure at 650℃-750℃ for up to 10,000 h.The results show that the impact toughness at room tempe rature drops rapidly at the early stage during thermal exposure at 700℃ and then has no significant change even if after exposure for 10,000 h.The significant decline of the impact toughness is attributed to the coarsening of M_(23)C_(6) carbides at grain boundaries,which weakens the grain boundary strength and leads to the aging-induced grain boundary embrittlement.The M_(23)C_(6) carbides have almost no change with further thermal exposure and the impact toughness also remains stable.Additionally,the impact toughness rises with the increase of thermal exposure temperature.The size of γ' after thermal exposure at 750℃ for10,000 h is much bigger than that at 650℃ and 700℃ for 10,000 h.There fore,the intragranular strength decreases significantly due to the transformation of the interaction between γ' and dislocation from stro ngly coupled dislocation shearing to Orowan bowing.More plastic deformation occurs within grains after thermal exposure at 750℃ for 10,000 h,which increases the impact toughness. 展开更多
关键词 Ni-Fe based alloy GH984G long-term thermal exposure Microstructure evolution Impact toughness
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Precipitates evolution and tensile behavior of wrought Ni-based ATI 718Plus superalloy during long-term thermal exposure 被引量:1
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作者 GUO QianYing JI KangKang +5 位作者 ZHANG Teng QIAO ZhiXia LI Chong LI Jun LIU ChenXi LIU YongChang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2022年第6期1283-1299,共17页
In this paper,the microstructure evolution and tensile behavior of wrought ATI 718 Plus superalloy during long-term thermal exposure(LTTE) were investigated.The γ’ phase evolves from spherical morphology to cuboidal... In this paper,the microstructure evolution and tensile behavior of wrought ATI 718 Plus superalloy during long-term thermal exposure(LTTE) were investigated.The γ’ phase evolves from spherical morphology to cuboidal morphology at 800℃,which is related to increasing γ’/γ misfit because of the increase of elastic energy.The amounts of η phase obviously increased and γ’ precipitate free zones(PFZs) were found in 800-LTTE samples due to the increase of η phase amount by consuming Al,Ti,and Nb.According to the formula of “MC+γ→M_(23)C_(6)+η”,η phase is also related to the decomposition of MC carbide,which involves the diffusion and segregation of Nb and Ti.In addition,some short rod-like and irregular Cr,Mo-rich σ phases were prone to precipitate near η phases after LTTE at 800℃ for 500 and 1000 h.σ phase has a crystallographic relationship with ηphase as(002)_(σ)//(10■0)_(η),[0■0]_(σ)//[01■0]_(η).The deteriorated tensile strength after LTTE is mainly attributed to that:(1) the evident coarsening of γ’ phase results in that the deformation mechanism transforms from stacking faults(SFs) shearing to Orowan looping,which is also convinced by calculated critical resolved shear stress(CRSS);(2) the noticeable increasing number of η phase contributes to stress concentration,resulting in micro-cracks formation;and (3) the apparently increasing number of η phase promotes the PFZs formation. 展开更多
关键词 ATI 718Plus superalloy long-term thermal exposure γ’coarsening ηphase σphase deformation mechanism
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Effect of Long-term Thermal Exposure on Microstructure and Stress Rupture Properties of GH3535 Superalloy 被引量:13
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作者 T.Liu J.S.Dong +4 位作者 L.Wang Z.J.Li X.T.Zhou L.H.Lou J.Zhang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2015年第3期269-279,共11页
The evolution of microstructure and the stress rupture properties of long term thermally exposed GH3535 alloy have been investigated. It was found that M6 C carbides presented in the solid solution heat treated sample... The evolution of microstructure and the stress rupture properties of long term thermally exposed GH3535 alloy have been investigated. It was found that M6 C carbides presented in the solid solution heat treated samples. During long term thermal exposure at 700 C, fine M12 C carbides precipitated preferentially at grain boundaries. These carbides coexisted with the pre-exiting M6 C. The stress rupture life of700 C/1000 h exposed sample under creep testing at 650 C/324 MPa is 93 h. It is much longer than that of the solid solution samples. No noticeable changes could be detected in both the microstructure and stress rupture lives when the samples were exposed for time longer than 1000 h M12 C carbides were found to be beneficial to the creep properties. The cracks initiated at the interface of M6 C carbides and matrix, which led to a lower creep rupture life. 展开更多
关键词 GH3535 superalloy Long term thermal exposure Micro
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Effect of Long-Term Thermal Exposures on Tensile Behaviors of K416B Nickel-Based Superalloy 被引量:4
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作者 Mao-Kai Chen Jun Xie +6 位作者 De-Long Shu Gui-Chen Hou Shu-Ling Xun Jin-Jiang Yu Li-Rong Liu Xiao-Feng Sun Yi-Zhou Zhou 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2020年第12期1699-1708,共10页
The effect of long-term thermal exposure on the tensile behavior of a high W content nickel-based superalloy K416B was investigated.The microstructure and the deformation characteristics were observed by scanning elec... The effect of long-term thermal exposure on the tensile behavior of a high W content nickel-based superalloy K416B was investigated.The microstructure and the deformation characteristics were observed by scanning electron microscopy and transmission electron microscopy,and the phase transformation of the alloy during long-term thermal exposure was analyzed by X-ray diffraction patterns and differential thermal analysis.Results showed that after thermal exposure at 1000℃,the MC carbides in the K416 B alloy decomposed into M_(6)C.During tensile deformation,dislocations slipping inγmatrix crossed over the M_(6)C by Orowan bowing mechanism.With the increase of thermal exposure time,the secondary M_(6)C reduced greatly the yield strength of the alloy at room temperature.Meanwhile,the continuous distribution of the secondary M_(6)C with great brittleness in the grain boundary could become the main source of crack,which might change the fracture characteristic of the alloy from trans-granular to intergranular. 展开更多
关键词 K416B superalloy thermal exposure Deformation mechanism Fracture characteristics
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Evolution of γ’ Particles in Ni-Based Superalloy Weld Joint and Its Effect on Impact Toughness During Long-Term Thermal Exposure
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作者 Xian-Kai Fan Fu-Quan Li +3 位作者 Lei Liu Hai-Chao Cui Feng-Gui Lu Xin-Hua Tang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2020年第4期561-572,共12页
Effects of long-term thermal exposure on γ’ particles evolution and impact toughness in the weld joint of Nimonic 263(N263)superalloy were deeply studied at 750℃.Results showed that the precipitates in the weld met... Effects of long-term thermal exposure on γ’ particles evolution and impact toughness in the weld joint of Nimonic 263(N263)superalloy were deeply studied at 750℃.Results showed that the precipitates in the weld metal were mainly composed of fine γ’ particles,bulky MC carbides,and small M23C6 carbides.With the thermal exposure time increasing from o to 3000 h,γ’ particles in the weld metal grew up from 19.7 nm to 90.1 nm at an extremely slow rate.After being exposed for 1000 h,γ’ particles coarsened and some of them transformed into acicular η phase.At the same time,MC carbides decomposed to form η phase and γ’ particles.This dynamic transition ensured the slight reduction in impact toughness of the weld metal after the thermal exposure,which indicated the stable serving performance of N263 weld joint. 展开更多
关键词 NI-BASED SUPERALLOY WELD joint long-term thermal exposure γ’Phase EVOLUTION Impact TOUGHNESS
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Microstructure evolution of laser deposited Ti60A titanium alloy during cyclic thermal exposure 被引量:4
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作者 张阿莉 刘栋 +1 位作者 汤海波 王华明 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第11期3249-3256,共8页
Cyclic thermal exposure tests of infrared heating to 800 ℃ in 120 s followed by compressed air cooling to 150 ℃ in 60 s were performed for the laser deposited Ti60A (Ti5.54Al3.38Sn3.34Zr0.37Mo0.46Si) alloy. The ef... Cyclic thermal exposure tests of infrared heating to 800 ℃ in 120 s followed by compressed air cooling to 150 ℃ in 60 s were performed for the laser deposited Ti60A (Ti5.54Al3.38Sn3.34Zr0.37Mo0.46Si) alloy. The effects of thermal exposure cycles on length ofβphase, area fraction ofαphase and microhardness of alloy were examined by OM, SEM and EDS. The results indicate that thermal exposure cycles have significant effects on length ofβphase, area fraction ofαphase and microhardness of the alloy. The original fine basket-weaveβand 78.5%αtransform to transient wedge-likeβ, finally leaving granularβand 97.6%coarsenedαwith the increased thermal exposure cycles. The formation mechanism of coarsenedαand broken-upβmicrostructure is discussed. The alloy after 750 thermal exposure cycles has the maximum microhardness, 33.3%higher than that of the as-deposited alloy. 展开更多
关键词 laser melting deposition titanium alloy cyclic thermal exposure MICROSTRUCTURE
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Effect of thermal exposure on microstructure and mechanical properties of Al-Si-Cu-Ni-Mg alloy produced by different casting technologies 被引量:10
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作者 Jia-ying ZHANG Li-jie ZUO +4 位作者 Jian FENG Bing YE Xiang-yang KONG Hai-yan JIANG Wen-jiang DING 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第7期1717-1730,共14页
The effect of thermal exposure at 350 ℃ for 200 h on microstructure and mechanical properties was investigated for Al-Si-Cu-Ni-Mg alloy, which was produced by permanent mold casting(PMC) and high pressure die casting... The effect of thermal exposure at 350 ℃ for 200 h on microstructure and mechanical properties was investigated for Al-Si-Cu-Ni-Mg alloy, which was produced by permanent mold casting(PMC) and high pressure die casting(HPDC). The SEM and IPP software were used to characterize the morphology of Si phase in the studied alloys. The results show that the thermal exposure provokes spheroidization and coarsening of eutectic Si particles. The ultimate tensile strength of the HPDC alloy after thermal exposure is higher than that of the PMC alloy at room temperature. However, the TEPMC and TEHPDC alloys have similar tensile strength around 67 MPa at 350 ℃. Due to the coarsening of eutectic Si, the TEPMC alloy exhibits better creep resistance than the TEHPDC alloy under studied creep conditions. Therefore, the alloys with small size of eutectic Si are not suitably used at 350 ℃. 展开更多
关键词 Al-Si-Cu-Ni-Mg alloy thermal exposure COARSENING creep behavior
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Influence of thermal exposure on microstructure and stress rupture properties of a new Re-containing single crystal Ni-based superalloy 被引量:2
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作者 Chen-guang Liu Yun-song Zhao +3 位作者 Jian Zhang Ding-zhong Tang Chun-zhi Li Zhen-ye Zhao 《China Foundry》 SCIE 2018年第1期51-57,共7页
In this study, the long-term thermal microstructural stability and related stress rupture lives of a new Re-containing Ni-based single-crystal superalloy, DD11, were investigated after high-temperature exposure for di... In this study, the long-term thermal microstructural stability and related stress rupture lives of a new Re-containing Ni-based single-crystal superalloy, DD11, were investigated after high-temperature exposure for different lengths of time. The results show that the γ' precipitates retained a cuboidal morphology and the γ' size increased after short thermal exposure for 50 h at 1,070℃. As the thermal exposure time was prolonged to 500 h, the cuboidal γ' gradually changed into irregular raft-like morphology due to particles coalescence, and the morphology of the microstructure was almost unchanged after further thermal exposure up to 3,000 h. The stress rupture experiments at 1,070℃ and a tensile stress of 140 MPa showed that the rupture lives increased significantly after thermal exposure for 50 h and dropped dramatically with increasing exposure time up to 500 h but decreased slowly after exposure for more than 500 h. These results imply that stress rupture properties did not decrease when the γ' remained cuboidal but degraded to different extents during the γ' coarsening process. The coarsening of the γ' precipitates and change in morphology were regarded as the main factors leading to the degradation of the stress rupture lives. This study provides fundamental information on the high-temperature longterm microstructural stability and mechanical performance, which will be of great help for DD11 alloy optimization and engineering aeroengine applications. 展开更多
关键词 Ni-based superalloy thermal exposure MICROSTRUCTURE COARSENING stress-rupture properties
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Spatiotemporal phase change materials for thermal energy long-term storage and controllable release
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作者 Yangeng Li Yan Kou +4 位作者 Keyan Sun Jie Chen Chengxin Deng Chaohe Fang Quan Shi 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第5期228-236,I0006,共10页
Phase change materials(PCMs)have attracted much attention in the field of solar thermal utilization recently,due to their outstanding thermal energy storage performance.However,PCMs usually release their stored latent... Phase change materials(PCMs)have attracted much attention in the field of solar thermal utilization recently,due to their outstanding thermal energy storage performance.However,PCMs usually release their stored latent heat spontaneously as the temperature below the phase transition temperature,rendering thermal energy storage and release uncontrollable,thus hindering their practical application in time and space.Herein,we developed erythritol/sodium carboxymethylcellulose/tetrasodium ethylenediaminetetraacetate(ERY/CMC/EDTA-4Na)composite PCMs with novel spatiotemporal thermal energy storage properties,defined as spatiotemporal PCMs(STPCMs),which exhibit the capacity of thermal energy long-term storage and controllable release.Our results show that the composite PCMs are unable to lose latent heat due to spontaneous crystallization during cooling,but can controllably release thermal energy through cold crystallization during reheating.The cold-crystallization temperature and enthalpy of composite PCMs can be adjusted by proportional addition of EDTA-4Na to the composite.When the mass fractions of CMC and EDTA-4Na are both 10%,the composite PCMs can exhibit the optical coldcrystallization temperature of 51.7℃ and enthalpy of 178.1 J/g.The supercooled composite PCMs without latent heat release can be maintained at room temperature(10-25℃)for up to more than two months,and subsequently the stored latent heat can be controllably released by means of thermal triggering or heterogeneous nucleation.Our findings provide novel insights into the design and construction of new PCMs with spatiotemporal performance of thermal energy long-term storage and controllable release,and consequently open a new door for the development of advanced solar thermal utilization techniques on the basis of STPCMs. 展开更多
关键词 Phase change materials long-term thermal storage Controllable release ERYTHRITOL
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TEM study on microstructures and properties of 7050 aluminum alloy during thermal exposure 被引量:5
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作者 沈凯 陈金灵 尹志民 《中国有色金属学会会刊:英文版》 EI CSCD 2009年第6期1405-1409,共5页
The microstructures of 7050 aluminum alloy under different thermal exposure conditions were investigated by means of transmission electron microscopy(TEM),high resolution electron microscopy(HREM)and tensile test.Guin... The microstructures of 7050 aluminum alloy under different thermal exposure conditions were investigated by means of transmission electron microscopy(TEM),high resolution electron microscopy(HREM)and tensile test.Guinier preston(GP)zone andη′phase are the main precipitates in original 7050 alloy.The orientation relationship betweenη′and matrix is Al [0001]η′//[111] andA l (1010)η′//(110).When the alloy is exposed at different temperatures for 500 h,with the thermal exposure temperature increasing,it can be seen under TEM that the precipitates become larger and the width of precipitate free zones(PFZ)becomes larger. The higher temperature the alloy is exposed at,the more the strength is reduced.Both GP zones andη′precipitates getting coarser and the PFZ getting wider should be responsible for the strength decline and elongation rise of 7050 alloy during thermal exposure. 展开更多
关键词 7050铝合金 透射电镜 透射电子显微镜 热性能 高分辨电子显微镜 7050合金 曝光 微观
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Particle Size Optimization of Thermochemical Salt Hydrates for High Energy Density Thermal Storage
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作者 Andrew Martin Drew Lilley +1 位作者 Raνi Prasher Sumanjeet Kaur 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第2期326-333,共8页
Thermal energy storage(TES)solutions offer opportunities to reduce energy consumption,greenhouse gas emissions,and cost.Specifically,they can help reduce the peak load and address the intermittency of renewable energy... Thermal energy storage(TES)solutions offer opportunities to reduce energy consumption,greenhouse gas emissions,and cost.Specifically,they can help reduce the peak load and address the intermittency of renewable energy sources by time shifting the load,which are critical toward zero energy buildings.Thermochemical materials(TCMs)as a class of TES undergo a solid-gas reversible chemical reaction with water vapor to store and release energy with high storage capacities(600 kWh m^(-3))and negligible self-discharge that makes them uniquely suited as compact,stand-alone units for daily or seasonal storage.However,TCMs suffer from instabilities at the material(salt particles)and reactor level(packed beds of salt),resulting in poor multi-cycle efficiency and high-levelized cost of storage.In this study,a model is developed to predict the pulverization limit or Rcrit of various salt hydrates during thermal cycling.This is critical as it provides design rules to make mechanically stable TCM composites as well as enables the use of more energy-efficient manufacturing process(solid-state mixing)to make the composites.The model is experimentally validated on multiple TCM salt hydrates with different water content,and effect of Rcrit on hydration and dehydration kinetics is also investigated. 展开更多
关键词 high energy density hydration kinetics long-term cycling thermal energy storage thermochemical materials
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Long-term ocean temperature trend and marine heatwaves
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作者 Min ZHANG Yangyan CHENG +4 位作者 Gang WANG Qi SHU Chang ZHAO Yuanling ZHANG Fangli QIAO 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第4期1037-1047,共11页
Marine heatwaves(MHWs)can cause irreversible damage to marine ecosystems and livelihoods.Appropriate MHW characterization remains difficult,because the choice of a sea surface temperature(SST)temporal baseline strongl... Marine heatwaves(MHWs)can cause irreversible damage to marine ecosystems and livelihoods.Appropriate MHW characterization remains difficult,because the choice of a sea surface temperature(SST)temporal baseline strongly influences MHW identification.Following a recent work suggesting that there should be a communicating baseline for long-term ocean temperature trends(LTT)and MHWs,we provided an effective and quantitative solution to calculate LTT and MHWs simultaneously by using the ensemble empirical mode decomposition(EEMD)method.The long-term nonlinear trend of SST obtained by EEMD shows superiority over the traditional linear trend in that the data extension does not alter prior results.The MHWs identified from the detrended SST data exhibited low sensitivity to the baseline choice,demonstrating the robustness of our method.We also derived the total heat exposure(THE)by combining LTT and MHWs.The THE was sensitive to the fixed-period baseline choice,with a response to increasing SST that depended on the onset time of a perpetual MHW state(identified MHW days equal to the year length).Subtropical areas,the Indian Ocean,and part of the Southern Ocean were most sensitive to the long-term global warming trend. 展开更多
关键词 marine heatwaves(MHWs) ensemble empirical mode decomposition(EEMD) long-term temperature(LTT)trend total heat exposure(THE)
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Influence of Thermal Exposure on Mechanical Properties of C/Al Composite
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作者 郭树启 隋全武 +1 位作者 郭文旭 唐凤军 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1990年第4期268-271,共4页
In this paper were studied the microstructure and properties of the non-barrier coating compo- sites fabricated by a new technology.The bonding between C and A1 in the composites is quite well, and the composites have... In this paper were studied the microstructure and properties of the non-barrier coating compo- sites fabricated by a new technology.The bonding between C and A1 in the composites is quite well, and the composites have excellent properties.The ion probe and X-ray analyses indicate that there is Al_4C_3 phase in the composites and its amount in the composites increases when the composites are exposed.In the case of exposure the strength of the composites is reduced because of increasing amount of Al_4C_3. 展开更多
关键词 C/Al composite MICROSTRUCTURE STRENGTH thermal exposure
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Evolution of surface roughness of a cast Al-Si-Cu piston alloy during thermal exposure
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作者 BAO Tong LI Jian-ping +7 位作者 LIU Lei LI Hai-ying YANG Zhong WANG Jian-li GUO Yong-chun LI Bo-yan YANG Wei ZHENG Jia-qi 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第6期1645-1653,共9页
In the present work,samples of Al-Si-Cu piston alloy after T6 heat treatment were exposed for 2 h at temperatures ranging from 400 to 550°C.The evolution of surface roughness and microstructure of the alloy durin... In the present work,samples of Al-Si-Cu piston alloy after T6 heat treatment were exposed for 2 h at temperatures ranging from 400 to 550°C.The evolution of surface roughness and microstructure of the alloy during thermal exposure was studied by combination methods of roughness profiles,optical and scanning electron microscopy as well as XRD analysis.It is found that the roughness and mass of the alloy increase with the raise of the thermal exposure temperature,and the increasing rates of them are slow as the exposure temperature is below 500°C,but accelerates abruptly when the temperature is higher than 500°C.The variation of surface roughness of the alloy is closely related to phase transformation and oxidation during the thermal exposure. 展开更多
关键词 surface roughness thermal exposure Al-Si-Cu piston alloy MICROSTRUCTURE OXIDATION
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Experimental study on axial compressive behaviors of prefabricated composite thermal insulation walls after single-side fire exposure
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作者 Fu Qian Zhu Xiaojun +4 位作者 Liang Shuting Yang Jian Li Xiangmin Xu Qingfeng Gao Mingzhu 《Journal of Southeast University(English Edition)》 EI CAS 2018年第2期220-228,共9页
The axial bearing capacity of prefabricated composite walls composed of inner and outer concrete wythes,expandable polystyrene(EPS)boards and steel sleeve connectors is investigated.An experimental study on the axial ... The axial bearing capacity of prefabricated composite walls composed of inner and outer concrete wythes,expandable polystyrene(EPS)boards and steel sleeve connectors is investigated.An experimental study on the axial bearing capacity of four prefabricated composite walls after fire treatment is carried out.Two of the prefabricated composite walls are normal-temperature specimens,and the others are treated with fire.The damage modes and crack development are observed,and the axial bearing capacity,lateral deformation of the specimens,and the concrete and reinforcing bar strain are tested.The results show that the ultimate bearing capacity of specimens after a fire is less than that of normal-temperature specimens;when the insulation board thicknesses are 40 mm and 60 mm,the decrease amplitudes are 20.8%and 16.8%,respectively.The maximum lateral deformation of specimens after a fire is greater than that of normal-temperature specimens,and under the same level of load,the lateral deformation increases as the insulation board thickness increases.Moreover,the strain values of the concrete and reinforcing bars of specimens after a fire are greater than those of normal-temperature specimens,and the strain values increase as the thickness of insulation board increases. 展开更多
关键词 prefabricated composite thermal insulation walls expandable polystyrene board fire exposure insulation layer post-re axial compressive behavior
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Water Absorption Capacity and Coating Adhesion on Thermally Modified and Not-Modified Spruce Wood(Blue Stained or Free of Blue Stained)
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作者 Demiao Chu Redžo Hasanagić +2 位作者 Leila Fathi Mohsen Bahmani Miha Humar 《Journal of Renewable Materials》 EI 2023年第12期4061-4078,共18页
This study aimed to investigate the water absorption capacity of thermally modified and non-modified spruce and blue-stained spruce wood.The wettability of wood depends on various factors,including its type,density,po... This study aimed to investigate the water absorption capacity of thermally modified and non-modified spruce and blue-stained spruce wood.The wettability of wood depends on various factors,including its type,density,porosity,and surface treatment.Wood can swell and become distorted when exposed to water or humidity,impacting its structural integrity.Hence,it is crucial to consider the water and water vapour uptake in the wood when choosing materials for applications that are likely to be exposed to moisture.Various moisture absorption tests were conducted to assess water absorption capacity,including short-term and long-term water absorption and water vapour absorption.The results showed a significant difference in the long-term exposure to water,which was related to the density of the wood.The study examined the influence of thermal treatment on the physical properties of wood and observed significant variations in mass change due to coating,indicating differences in adhesion among different wood types.Vacuum-treated blue-stained Norway spruce demonstrated higher adhesion(5%–15%)compared to air-treated samples.Furthermore,cohesion tests revealed lower cohesion force in blue-stained Norway spruce(approximately 20%–30%)compared to Norway spruce.The study also used industry-standard tests to investigate the adhesion and cohesion of nano-coatings on wood surfaces.The results provided valuable information on the properties of coatings applied to wood,which is vital in protecting and decorating wood while also providing preventive protection against wood pests,weathering,and mechanical influences.Wood modification in vacuum involves subjecting the wood to a low-pressure environment to remove air and moisture,allowing for deeper and more uniform penetration of treatment chemicals.In contrast,wood modification in air relies on the natural circulation of air to facilitate the absorption of chemical treatments,without the need for a vacuum chamber. 展开更多
关键词 Wood durability long-term exposure moisture absorption WETTABILITY ABSORPTION
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Thermally Evaporated ZnSe for Efficient and Stable Regular/Inverted Perovskite Solar Cells by Enhanced Electron Extraction
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作者 Xin Li Guibin Shen +6 位作者 Xin Ren Ng Zhiyong Liu Yun Meng Yongwei Zhang Cheng Mu Zhi Gen Yu Fen Lin 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第5期440-448,共9页
Electron transport layers(ETLs)are crucial for achieving efficient and stable planar perovskite solar cells(PSCs).Reports on versatile inorganic ETLs using a simple film fabrication method and applicability for both l... Electron transport layers(ETLs)are crucial for achieving efficient and stable planar perovskite solar cells(PSCs).Reports on versatile inorganic ETLs using a simple film fabrication method and applicability for both low-cost planar regular and inverted PSCs with excellent efficiencies(>22%)and high stability are very limited.Herein,we employ a novel inorganic ZnSe as ETL for both regular and inverted PSCs to improve the efficiency and stability using a simple thermal evaporation method.The TiO_(2)-ZnSe-FAPbl_(3)heterojunction could be formed,resulting in an improved charge collection and a decreased carrier recombination further proved through theoretical calculations.The optimized regular PSCs based on TiO_(2)/ZnSe have achieved 23.25%efficiency with negligible hysteresis.In addition,the ZnSe ETL can also effectively replace the unstable bathocuproine(BCP)in inverted PSCs.Consequently,the ZnSe-based inverted device realizes a champion efficiency of 22.54%.Moreover,the regular device comprising the TiO_(2)/ZnSe layers retains 92%of its initial PCE after 10:00 h under 1 Sun continuous illumination and the inverted device comprising the C_(60)/ZnSe layers maintains over 85%of its initial PCE at 85℃for 10:00 h.This highlights one of the best results among universal ETLs in both regular and inverted perovskite photovoltaics. 展开更多
关键词 high efficiency long-term stability planar regular/inverted perovskite solar cells thermal evaporation ZnSe electron transport layer
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