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Journal of Materials Science & Technology 2021年第34期93卷 147-156页

作者： Yaqun Xu Yu Fu Juan Li Wenlong Xiao Xinqing Zhao Chaoli Ma Key Laboratony of Aerospace Advanced Materials and Perfrmance of Ministry of Educatin School of Materials Science and EngineeringBeihang UniversityBeijing 100191China Yunnan Innovarion Institute of Beihang University Kunming 650000China

The microstructural evolution,oxidation resistance and mechanical properties of Ti-6.5Al-2Sn-4Hf-2 Nbbased alloys with different contents of tungsten(W)additions ranging from 0 to 4.0 wt.%have been investigated in this study.The addition of W changed the microstructure from Widmanstatten colony of the W-free alloy to basketweave microstructure.After thermal exposure at 650℃ for 1000 h,the retainedβphase became less continuous,and secondaryβnano-particles with high W concentration were precipitated fromαlamellas.Withinαlamellas,the W was found to mainly partitioned into the secondaryβphase and refined the ordered α_(2)-Ti_(3)Al precipitates due to increased solubility of Nb in α_(2) phase.high W addition increased activation energy for oxidation,promoting the formation of more uniform and compact compound oxides,therefore substantially enhanced the oxidation resistance of the alloy.Besides,the W addition also improved the room and high-temperature yield strength without obviously losing plasticity after long-time thermal exposure.The improved mechanical performance was mainly attributed to the introduction of moreα/βinterfaces,the precipitation of secondaryβphase and the refinedα_(2) phase with Nb segregation.

关键词： Titanium alloy high temperature Microstructure Oxidation Mechanical properties

Isothermal bulk modulus and its first pressure derivative of NaCl at high pressure and high temperature

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Chinese Physics B 2012年第3期21卷 355-359页

作者：宋婷孙小伟刘子江李建丰田俊红 School of Mathematics and Physics Lanzhou Jiaotong University Department of Physics Lanzhou City University

The isothermal bulk modulus and its first pressure derivative of NaCl are investigated using the classical molecular dynamics method and the quasi-harmonic Debye model. To ensure faithful molecular dynamics simulations, two types of potentials, the shell-model （SM） potential and the two-body rigid-ion Born-Mayer-Huggins-FumiqTosi （BMHFT） potential, are fully tested. Compared with the SM potential based simulation, the molecular dynamics simulation with the BMHFT potential is very successful in reproducing accurately the measured bulk modulus of NaCl. Particular attention is paid to the prediction of the isothermal bulk modulus and its first pressure derivative using the reliable potential and to the comparison of the SM and the BMHFT potentials based molecular dynamics simulations with the quasi-harmonic Debye model. The properties of NaCl in the pressure range of 0-30 GPa at temperatures up to the melting temperature of 1050 K are investigated.

关键词： isothermal bulk modulus NaCl high pressure high temperature

Surface Structure of Large Synthetic Diamonds by high temperature and high Pressure

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Chinese Physics Letters 2007年第10期24卷 2991-2993页

作者：臧传义黄国峰马红安贾晓鹏 Institute of Material Science and Engineering Henan Polytechnic University Jiaozuo 454000 Key National Laboratory for Superhard Materials Jilin University Changchun 130012

With NiMnCo and FeCoNi alloys as solvent metals, large single-crystal diamonds of about 3mm across are grown by temperature gradient method （TGM） under high temperature and high pressure （HPHT）. Although both {100} and {111} surfaces are developed by a layer growth mechanism, some different characteristic patterns are seen clearly on the different surfaces, no matter whether NiMnCo or FeCoNi alloys are taken as the solvent metals. For {100} surface, it seems to have been melted or etched greatly, no dendritic patterns to be found, and only a large number of growth hillocks are dispersed net-likely; while for {111} surface, it often seems to be more smooth-faced, no etched or melted traces are present even when a lot of depressed trigonal growth layers. This distinct difference between {111} and {100} surfaces is considered to be related to the difference of surface-atom distribution of different surfaces, and {111} surfaces should be more difficult to be etched and more steady than {100} surfaces.

关键词： Surface Structure Large Synthetic Diamonds high temperature

Effect of La_2O_3 on the wear behavior of MoSi_2 at high temperature

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Journal of Rare Earths 2011年第4期29卷 370-373页

作者：张厚安古思勇谢能平 Institute of Material Preparation and Applied Technology Xiamen University of Technology College of Electromechanical Engineering Hunan University of Science and Technology

Wear behaviors of MoSi2 doped with La2O3 against SiC under different loads at 1000 oC in air were investigated by using an XP-5 type high temperature friction and wear tester. The worn surfaces and phases of the samples were analyzed by scanning electron microscopy （SEM） and X-ray diffraction, respectively. Results showed that the addition of La2O3 could obviously improve wear resistance of MoSi2. Because of the formation of MoO3 phase on the worn surface, La2O3/MoSi2 composite mainly exhibited oxidation and abrasive wear, which was different from the wear form of MoSi2 such as adhesion, oxidation and abrasion.

关键词： MoSi2 matrix composite wear high temperature La2O3 SiC rare earths

Influence of Exercise at high temperature on Blood Biochemical Indexes and HSP72 Expression in Adult Males

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Journal of Huazhong University of Science and Technology(Medical Sciences) 2008年第5期28卷 504-507页

作者：唐忠志翁少凡彭森刘跃伟陈晓娟杨剑虹陆卫华陈卫红 Department of Emergency Medicine Wuhan General Hospital of Guangzhou Military Command School of Public Health Tongji Medical College Huazhong University of Science and Technology

The influence of exercise at high temperature on adult males＇ routine blood indexes and biochemical indexes and the expression of HSP72 in peripheral blood lymphocytes （PBLs） was studied in order to provide theoretical ground for health supervision of adults receiving exercise at high temperature. 180 adult males were selected and divided into exercise group and control group, in which the exercise group was subdivided into subgroup 1 and subgroup 2 receiving exercise at high temperature in the afternoon and in the morning, respectively. Peripheral venous blood was phle- botomized before and after the exercise to examine routine blood indexes and blood biochemical indexes. The expression levels of HSP72 in PBLs were detected by flow cytometry. The results showed that the routine blood indexes and biochemical indexes in each group were within the range of normal values of male adults. There was no significant difference between each exercise group and control group in indexes before exercise. After exercise, the expression levels of HSP72 in PBLs in exercise groups were higher than those before exercise, and HSP72 expression levels in subgroup 1 were obviously higher than those in subgroup 2 and control group. The contents of ALT, urea, Na＋, Cl-, Ca2＋ and K＋ in subgroups 1 and 2 were lower than those in control group, but CK level was higher than in control group （P〈0.05）. The contents of Na＋ and Clin subgroup 1 were relatively lower than those in subgroup 2 （P〈0.05）. It was concluded that while receiving exercise at high temperature, adult males＇ HSP72 levels in PBLs could be increased and the biochemical indexes changed. Attention should be paid to health supervision to avoid obvious body injuries at high temperature.

关键词： high temperature exercise blood routine indexes biochemical indexes HSP72

ISOCHRONOUS STRESS-STRAIN CURVES OF LOW ALLOY STEEL CROSS-WELD-SPECIMEN AT high temperature

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 612-617页

作者： C.W.Ma F.Z.Xuan Z.D.Wang S.T.Tu East China University of Science and Technology Shanghai 200237 ChinaEast China University of Science and Technology Shanghai 200237 ChinaEast China University of Science and Technology Shanghai 200237 ChinaEast China University of Science and Technology Shanghai 200237 China Nanjing University of Technology Nanjing 210009 China

In this work, a parametric approach is presented and utilized to determine the creep properties of weldments; then the model of creep strain for cross weld specimen is given. On the basis of the experimental results, attempt has been made to establish equations of the isochronous stress-strain for weld joint that can predict the function of loading and service time in use of the creep data of base metal and weld metal.

关键词： isochronous stress-strain curve creep deformation high temperature welded joint low alloy steel

Detection of Thermophysical Properties for high Strength Concrete after Exposure to high temperature

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Journal of Wuhan University of Technology(Materials Science) 2017年第1期32卷 113-120页

作者：杜红秀 WU Jia LIU Gaili WU Huiping YAN Ruizhen College of Architecture and Civil Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Electric Power Research Institute Taiyuan 030001China

Using the detection principle of infrared thermal imaging technique and the detection principle of DRH thermal conductivity tester laboratory,we investigated the infrared thermal image inspection,coefficient of thermal conductivity,apparent density,and compressive strength test on C80 high-strength concrete（HSC） in the presence and absence of polypropylene fibers under completely heated conditions.Only slight damages were detected below 400 ℃,whereas more and more severe deterioration events were expected when the temperature was above 500 ℃.The results show that the elevated temperature through infrared images generally exhibits an upward trend with increasing temperature,while the coefficient of thermal conductivity and apparent density decrease gradually.Additionally,the addition of polypropylene fibers with appropriate length,diameter,and quantity contributes to the improvement of the high-temperature resistance of HSC.

关键词： high-strength concrete polypropylene fiber high temperature infrared thermal imaging technique coefficient of thermal conductivity compressive strength ratio

Bond Behavior between BFRP Bars and Hybrid Fiber Recycled Aggregate Concrete after high temperature

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Journal of Renewable Materials 2021年第3期9卷 507-521页

作者： Boheng Zhu Huaxin Liu Genjin Liu Abasal Hussain Xiaofei Zhang Xuezhi Wang College of Civil and Architectural Engineering Liaoning University of TechnologyJinzhou121000China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian116024China Institute of Water Resources and Hydro-electric Engineering Xi’an University of TechnologyXi’an710048China

The aim of this study is to improve the bond performance of basalt fiber reinforced polymer(BFRP)bars and recycled aggregate concrete(RAC)after being exposed to high temperatures.The bond behavior(failure modes,bond strength,bond stress-slip curves)between BFRP bars and hybrid fiber recycled aggregate concrete(HFRAC)after being exposed to temperatures ranging from 20℃up to 500℃was studied by using pull-out tests.The effect of high temperatures on mechanical properties of concrete(compressive strength,splitting tensile strength)and tensile strength of BFRP bars was also investigated.The bond strength decreased as the temperature increased and the drop of bond strength between RAC and BFRP bar was larger than that between HFRAC and BFRP bar.As the temperature rises,the key factor affecting the bond strength was gradually transformed from concrete strength to BFRP bar strength.The relationship between bond stress and slip in the dimensionless bond stress-slip ascending section was established,which was in good agreement with the experimental results.

关键词： high temperature BFRP bar hybrid fiber recycled aggregate concrete bond performance

Effect of high temperature on the expressions of genes encoding starch synthesis enzymes in developing rice endosperms

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Journal of Integrative Agriculture 2015年第4期14卷 642-659页

作者： CAO Zhen-zhen PAN Gang WANG Fu-biao WEI Ke-su LI Zhao-wei SHI Chun-hai GENG Wei CHENG Fang-min College of Agriculture and Biotechnology Zhejiang University

high temperature is the major environmental factor affecting grain starch properties of cooking rice cultivars. In this study, two non-waxy indica rice genotypes, cv. 9311 and its mutant with extremely high amylose phenotype（9311eha） were used to study the differential expressions of genes in starch synthesis and their responses to high temperature（HT）. Significant increase in apparent amylose content and hot-water-soluble starch content in mutant 9311 eha were genetically caused by a substitution from AGTTATA to AGGTATA at the leader intron 5′ splice site in Wx gene. This mutation resulted in different m RNA transcript levels, m RNA splicing efficiencies and protein levels of Wx between the two rice genotypes, which also lead to the genotype-dependent alteration in the temporal pattern of Wx transcription and granule-bound starch synthase（GBSS） activity in response to HT. However, changes in the activities of other starch synthesizing enzymes and their expressions of distinct isoform genes were not significant with the Wx gene mutation, thus only minor difference in the particle size of starch granule, chain-length distribution and gelatinization enthalpy were found between the two genotypes. The temporal-specific expression of multiple isoform genes responsive to different temperature regiments indicated that the reduction of GBSS transcript expression under HT was generally accompanied by the decreased expressions of SSSIIa, SSSIIIa and SBEIIb. Consequently, high temperature-ripened grains in 9311 eha showed high proportion of intermediate and long B chains and somewhat lower level of short A chain compared to the wildtype. The temperature-dependent alteration of amylose content was not only attributed to the reduced expression of GBSS, but also associated with the complimentary effect of SSSIIa and SBEIIb.

关键词： rice starch synthesis gene expression amylopectin strucrute high temperature

Flexible mica films for high-temperature energy storage

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Journal of Materiomics 2018年第3期4卷 173-178页

作者： Xinwei Xu Wenlong Liu Yi Li Yifei Wang Qibin Yuan Jie Chen Rong Ma Feng Xiang Hong Wang State Key Laboratory for Mechanical Behavior of Materials&School of Electronic and Information Engineering Xi'an Jiaotong UniversityXi'an 710049China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

Dielectrics used for energy storage are highly desired for power electronics and pulse power applications and the polymer capacitors are the main commercial ones available.The development of flexible electronics and wearable devices require the relative materials being flexible.Besides,high temperature resistance is also desired because of the rising demand for high power devices and large electricity under elevated temperature.The polymer dielectrics for polymer capacitors are flexible but with relatively low working temperature normally less than 100℃.Therefore,fabricating a dielectric material to satisfy the flexibility and high working temperature simultaneously is still a great challenge.Here we propose one solution by demonstrating a hand-exfoliated fluorophlogopite film with micrometer scale thickness.Among which,the mica film with a thickness of around 10μm(Mica-10)exhibits the inorganic-like temperature stability even polymer-like flexibility.From 25℃to 200℃,Mica-10 has an energy density of around 11.27 J/cm^(3)with a variation within 2%,accompanied by a charge-discharge efficiency of around 95%at an electric field of 500 MV/m.Meanwhile,the thin thickness makes Mica-10 flexible,enabling its excellent flexibility and durability.This work revives the traditional material,mica,providing a way for high-temperature energy storage applications.

关键词： Dielectric Mica Energy storage high temperature Flexible