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一种低密度耐高温高比强度多层次结构双相高熵合金

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Science China Materials 2023年第2期66卷 780-792页

作者：李亚耸廖卫兵陈怀灿 Jamieson Brechtl 宋温丽殷雯何占兵 Peter k.Liaw 张勇 Beijing Advanced Innovation Center of Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China Spallation Neutron Source Science Center Institute of High Energy PhysicsChinese Academy of SciencesDongguan 523803China Energy and Transportation Science Division Oak RidgeTN37831USA Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN37996USA Beijing key Laboratory for Magneto-Photoelectrical Composite and Interface Science University of Science and Technology BeijingBeijing 100083China Shunde Graduate School of University of Science and Technology Beijing Foshan 528399China

本文研究了一种新型低密度(~6.24 g cm^(-3))双相AlTiVCoNi高熵合金,其组织结构由有序L21高熵金属间化合物、无序体心立方结构和纳米L21相多层次结构构成.该合金在1200℃+24 h热处理下未发生相结构转变,在此条件下具有优异的高温相结构... 详细信息

本文研究了一种新型低密度(~6.24 g cm^(-3))双相AlTiVCoNi高熵合金,其组织结构由有序L21高熵金属间化合物、无序体心立方结构和纳米L21相多层次结构构成.该合金在1200℃+24 h热处理下未发生相结构转变,在此条件下具有优异的高温相结构稳定性,其铸态和热处理态的压缩屈服强度相当,达到~1.6 GPa.另外,该合金在室温和600℃条件下表现出了优异的强塑性匹配和优异的比屈服强度,分别达到了约261和210 MPa g^(-1)cm^(3).该合金的超高强度主要源于有序L21相与体心立方相的半共格界面导致的一种强相结构稳定性和多层次结构的复合强化机制.该合金在800和1000℃压缩过程中出现了动态再结晶软化,使得其高温强度有所降低.这种“具有半共格界面L21+体心立方+纳米L21颗粒”的多层次结构设计为开发新型低密度耐高温高熵合金提供了一种新设计思路.

关键词：金属间化合物高熵合金体心立方双相多层次结构高比强度超高强度高温强度

New applications of a generalized Hooke's law for second gradient materials

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Theoretical & Applied Mechanics Letters 2015年第3期5卷 129-133页

作者： k.Enakoutsa Center for Advanced Vehicular Systems Mississippi State University

We provide analytical solutions to the problems of a circular bending of a beam in plane strain and the torsion of a non-circular cross-section beam, the beams obeying a second-gradient elasticity law proposed by the author, following a previous suggestion of delrlsola et al. （2009）. The motivation was to find benchmark analytical solutions that can serve to grasp the physical foundations of second gradient elasticity laws for heterogeneous materials. The analytical solution of the circular beam problem presents the additional advantage to establish some nice properties on the unknown second gradient elastic moduli introduced by Enakoutsa （2014） model and the classical elasticity constants for both incompressible and compressible heterogeneous elastic materials. A framework to find the elastic moduli of the new model is also proposed.

关键词： Second gradient theory Beam Analytical solution

On the binding energies of excitons in polar quantum well structures in a weak electric field

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Chinese Physics B 2005年第11期14卷 2314-2319页

作者：吴云峰梁希侠 k.k.Bajaj Department of Physics Inner Mongolia University Hohhot 010021 China Department of Physics Emory University Atlanta GA 30322 USA

The binding energies of excitons in quantum well structures subjected to an applied uniform electric field by taking into account the exciton longitudinal optical phonon interaction is calculated. The binding energies and corresponding Stark shifts for Ⅲ-Ⅴ and Ⅱ-Ⅵ compound semiconductor quantum well structures have been numerically computed. The results for GaAs/A1GaAs and ZnCdSe/ZnSe quantum wells are given and discussed. Theoretical results show that the exciton-phonon coupling reduces both the exciton binding energies and the Stark shifts by screening the Coulomb interaction. This effect is observable experimentally and cannot be neglected.

关键词： quantum confined stark effects exciton quantum well

THE PHOTOCHEMICAL SYNTHESIS OF THE PYRIDINE ADDUCT OF TETRAPHENYLPORPHYRINATORHODIUM(Ⅱ)AND THE MECHANISM OF PHOTOCHEMICAL REACTION

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Chinese Chemical Letters 1991年第4期2卷 279-280页

作者： A.k.Hsieh Department of Chemistry National University of Singapore

A new rhodium(Ⅱ)porphyrin complex was isolated by chromatography from the photochemical reac- tion of(μ—tetraphenylporphyrinato)bis[dicarbonylrhodium(Ⅰ)]with pyridine in benzene and has been charac- *** the result... 详细信息

关键词： TPP THE PHOTOCHEMICAL SYNTHESIS OF THE PYRIDINE ADDUCT OF TETRAPHENYLPORPHYRINATORHODIUM AND THE MECHANISM OF PHOTOCHEMICAL REACTION

Effect of H_2S Flow Rate and Concentration on Performance of H_2S/Air Solid Oxide Fuel Cell

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Chinese Journal of Chemical Engineering 2004年第2期12卷 306-309页

作者：钟理张腾云陈建军 WEI Guolin LUO Jingli k.Chung College of Chemical Engineering South China University of Technology Guangzhou 510640 China Department of Chemical and Materials Engineering University of Alberta Edmonton AB Canada T6G 2G6

A solid state H2S/air electrochemical cell having the configuration of H2S, (MoS2+NiS+Ag)/YSZ/Pt,air has been examined with different H2S flow rates and concentrations at atmospheric pressure and 750-850℃.Performance of the fuel cell was dependent on anode compartment H2S flow rate and concentration. The cell open-circuit voltage increased with increasing H2S flow rate. It was found that increasing both H2S flow rate and H2S concentration improved current-voltage and power density performance. This is resulted from improved gas diffusion in anode and increased concentration of anodic electroactive species. Operation at elevated H2S concentration improved the cell performance at a given gas flow rate. However, as low as 5% H2S in gas mixture can also be utilized as fuel feed to cells. Highest current and power densities, 1750mA·cm^-2 and 200mW·cm^-2,are obtained with pure H2S flow rate of 50 ml·min^-1 and air flow rate of 100ml·min^-1 at 850℃.

关键词： H2S 流动速度浓度固体氧化物燃料电池

Implementation of an All-Optical NOR Gate Using a Multi-Wavelength Injection-Locked Diode Laser

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光学学报 2003年第S1期23卷 397-398页

作者： k. k. Qureshi L. Y. Chan P. k. A. Wai L. F. k. Lui W. H. Chung Hwa-yaw Tam Photonics Research Center Department of Electrical Engineering The Hong Kong Polytechnic University Hung Horn Hong Kong.Photonics Research Center Department of Electronic and Information Engineering The Hong Kong Polytechnic University Hung Horn Hong Kong.Photonics Research Center Department of Electronic and Information Engineering The Hong Kong Polytechnic University Hung Horn Hong Kong.Photonics Research Center Department of Electronic and Information Engineering The Hong Kong Polytechnic University Hung Horn Hong Kong.Photonics Research Center Department of Electrical Engineering The Hong Kong Polytechnic University Hung Horn Hong Kong.Photonics Research Center Department of Electrical Engineering The Hong Kong Polytechnic University Hung Horn Hong Kong.

We demonstrated an all optical NOR gate operating at 10 Gb/s using a multi-wavelength mutual injection-locked Fabry-Perot laser diode (FP-LD).

关键词： NOR in on In of Implementation of an All-Optical NOR Gate Using a Multi-Wavelength Injection-Locked Diode Laser

Effect of lengthening along the anatomical axis of the femur and its clinical impact

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World Journal of Orthopedics 2017年第5期8卷 431-435页

作者： khaled M Emara Ahmed Nageeb Mahmoud Ahmed k Emara Mariam k Emara Limb Reconstruction and Deformity Correction Unit Orthopaedic Surgery Department Ain Shams University Hospitals

AIM To review and study the effect of lengthening along the anatomical axis of long bones and its relation to the mechanical axis *** We try in this review to calculate and discuss the exact clinical impact of lengthening along the anatomical axis of the femur on affecting the limb alignment. Also we used a trigonometric formula to predict the change of the femoral distal anatomical mechanical angle(AMA) after lengthening along the anatomical axis. RESULTS Lengthening along the anatomical axis of the femur by 10% of its original length results in reduction in the distal femoral AMA by 0.57 degrees. There is no objective experimental scientific data to prove that the Mechanical axis is passing via the center of the hip to the center of the knee. There is wide variation in normal anatomical axis for different populations. In deformity correction, surgeons try to reproduce the normal usual bone shape to regain normal function, which is mainly anatomical axis. CONCLUSION Lengthening of the femur along its anatomical axis results in mild reduction of the distal femoral AMA. This may partially compensate for the expected mechanical axis lateralisation and hence justify its minimal clinical impact.

关键词： Bone lengthening Deformity Femoral lengthening External fixation Intramedullary nail Axis deviation

Laser Surface Modification of Lean-alloyed Austenitic Stainless Steel for Corrosion Resistance

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腐蚀与防护 2012年第S1期33卷 55-61页

作者： Chan W k kwok C T Chan M C Lo k H University of Macao Av.Padre Tomás Pereira Taipa Macao China

In order to reduce the cost of the austenitic stainless steels(ASSs),the expensive austenite former(nickel) is often substituted by ***,manganese is generally seen to have a detrimental effect on the corrosion *** the present study,the feasibility of laser surface modification of a lean-alloyed ASS(FeCrMn) for enhancing pitting corrosion resistance was *** surface modification of FeCrMn was successfully achieved by a 2.3 kW high power diode laser(HPDL).Cyclic polarization tests for FeCrMn after laser surface modification in 3.5% NaCl solution at 25 ℃ were performed by using a *** pitting resistance of the laser-modified specimens was found to be significantly improved as reflected by the noble shift in pitting *** could be attributed to redistribution of manganese sulphide leading to a more homogenous and refined *** corrosion resistance of the laser-treated FeCrMn followed by subsequent citric acid passivation was found to be further improved as reflected by the noble shift in pitting potential to 0.18 V.

关键词： laser surface melting HPDL lean-alloyed austenite stainless steel pitting corrosion citric acid passivation

Murine studies and expressional analyses of human cardiac pericytes reveal novel trajectories of SARS-CoV-2 Spike protein-induced microvascular damage

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Signal Transduction and Targeted Therapy 2023年第7期8卷 3211-3214页

作者： Elisa Avolio Prashant k.Srivastava Jiahui Ji Michele Carrabba Christopher T.W.Tsang Yue Gu Anita C.Thomas kapil Gupta Imre Berger Costanza Emanueli Paolo Madeddu Bristol Medical School Translational Health SciencesUniversity of BristolBristolUK National Heart&Lung Institute Imperial CollegeLondonUK School of Biochemistry University of BristolBristolUK

Dear Editor,The Coronavirus disease 2019(COVID-19)pandemic has caused over 670 million cases and 6.7 million deaths worldwide,many of which are attributed to cardiovascular ***-induced endothelial damage,endothelial b... 详细信息

关键词： damage cardiovascular cardiac