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A NOVEL PARAMETER FOR EVALUATING THE FATIGUE CRACK GROWTH RATE IN CARBON sTEELs

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Acta Metallurgica sinica(English Letters) 2001年第4期14卷 271-279页

作者： x.s. wang1), s.Q. Zhn1), N. Kawagoishi2) and H. Nisitani3) 1) Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China 2) Faculty of Engineering, Kagoshima University, Kagoshima, 890-0065, Japan Department of Engineering Mechanics Tsinghua University Faculty of Engineering Kagoshima University

A novel parameter is suggested for evaluating the fatigue crack growth rate in carbon steels. Fatigue crack propagation tests of an annealed 0.42% carbon steel were carried out under different conditions to investigate the relationship between this dominating parameter and the crack opening displacement (COD). A new equation of fatigue crack growth rate is formulated in terms of the suggested parameter. The physical meanings of the material parameters in this equation are explored experimentally. Considering the relation of crack growth and deformation properties, a simple and applicable method is proposed to evaluate the fatigue crack growth rate. It is also observed that the material parameters in the fatigue crack growth rate equation of carbon steels are related linearly to the material strength. The results are in a good agreement with experimental results.

关键词： Crack propagation Evaluation Fatigue testing Parameter estimation

Fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

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Matter and Radiation at Extremes 2024年第3期9卷 11-18页

作者： Y.x.wang x.L.Zhu s.M.Weng P.Li x.F.Li H.Ai H.R.Pan Z.M.sheng Key Laboratory for Laser Plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFsA Shanghai Jiao Tong UniversityShanghai 200240China Research Center of Laser Fusion of China Academy of Engineering Physics MianyangSichuan 621900China state key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-IR)to terahertz(THz)range is of interest for applications in a number of fields,from fundamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-IR or THz ***,we present a photon deceleration scheme for the efficient generation of ultrashort mid-IR or THz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake ***,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer *** greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength IR and THz spectral ranges.

关键词： laser ultrashort photon

The autophagy protein Atg9 functions in glia and contributes to parkinsonian symptoms in a Drosophila model of Parkinson’s disease

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Neural Regeneration Research 2024年第5期19卷 1150-1155页

作者： shuanglong Yi Linfang wang Margaret s.Ho shiping Zhang school of Life science and Technology ShanghaiTech UniversityShanghaiChina College of Life sciences University of Chinese Academy of SciencesBeijingChina

Parkinson’s disease is a progressive neurodegenerative disease characterized by motor deficits,dopaminergic neuron loss,and brain accumulation ofα-synuclein aggregates called Lewy *** in protein degradation pathways,such as autophagy,has been demonstrated in neurons as a critical mechanism for eliminating protein aggregates in Parkinson’s ***,it is less well understood how protein aggregates are eliminated in glia,the other cell type in the *** the present study,we show that autophagy-related gene 9(Atg9),the only transmembrane protein in the autophagy machinery,is highly expressed in Drosophila glia from adult *** from immunostaining and live cell imaging analysis reveal that a portion of Atg9 localizes to the trans-Golgi network,autophagosomes,and lysosomes in ***9 is persistently in contact with these *** glial atg9 reduces the number of omegasomes and autophagosomes,and impairs autophagic substrate *** suggests that glial Atg9 participates in the early steps of autophagy,and hence the control of autophagic ***,loss of glial atg9 induces parkinsonian symptoms in Drosophila including progressive loss of dopaminergic neurons,locomotion deficits,and glial *** findings identify a functional role of Atg9 in glial autophagy and establish a potential link between glial autophagy and Parkinson’s *** results may provide new insights on the underlying mechanism of Parkinson’s disease.

关键词： Atg9 autophagy glia Parkinson’s disease

Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys with adjusting Y addition

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Journal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： J.A.Liu s.J.Liu B.wang W.B.sun x.J.Liu Z.W.Han College of Materials science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of Bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for Bionics-Jilin University Weihai 264205PR China

In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption *** characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),W-phase(Mg_(3)Zn_(3)Y_(2)),and LPsO phase(Mg_(12)ZnY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 MJ/m^(3)to 10.97 MJ/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

Distinct Electrical and Mechanical Responses of a Cu-10Fe Composite Prepared by Hot-Pressed sintering and Post Treatment

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Acta Metallurgica sinica(English Letters) 2024年第2期37卷 255-265页

作者： x.Y.Yue s.Y.Peng x.Zhang C.N.He Y.Z.Tian Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China school of Materials science and Engineering and Tianjin Key Laboratory of Composite and Functional Materials Tianjin UniversityTianjin300350China Research Centre for Metallic Wires Northeastern UniversityShenyang110819China

A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution *** hot-pressed sintered and solution treated materials were rolled and *** precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron *** contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe *** Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACs and softening temperature of 838 *** for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were *** findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.

关键词： Cu-Fe composite Hot-pressed sintering Thermal stability strength Electrical conductivity

Ge在Ru(0001)表面上生长及其性质研究

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物理学报 2005年第3期54卷 1330-1333页

作者：胡昉张寒洁吕斌陶永升李海洋鲍世宁何丕模王学森浙江大学物理系杭州310027 新加坡国立大学物理系新加坡119260

报道Ge在Ru(0 0 0 1)表面上生长以及相互作用行为的扫描隧道显微镜 (sTM)和x射线光电子能谱 (x.s.研究 .sTM的实验结果表明Ge在Ru(0 0 0 1)表面的生长呈典型的stranski_Krastanov生长模式 ,Ge的覆盖度小于单原子层时呈层状生长 ,而从第... 详细信息

报道Ge在Ru(0 0 0 1)表面上生长以及相互作用行为的扫描隧道显微镜 (sTM)和x射线光电子能谱 (x.s.研究 .sTM的实验结果表明Ge在Ru(0 0 0 1)表面的生长呈典型的stranski_Krastanov生长模式 ,Ge的覆盖度小于单原子层时呈层状生长 ,而从第二层开始呈岛状生长 .x.s.量显示衬底Ru(0 0 0 1)与Ge的相互作用很弱 .Ru(0 0 0 1)表面的Ru 3d5 2 和Ru 3d3 2 芯态结合能分别处于 2 79 8和 2 84 0eV .随着Ge的生长 ,到Ge层的厚度为 2 0个单原子层 ,衬底Ru 3d芯态结合能减小了约 0 2eV ,而Ge 3d芯态结合能从Ge低覆盖度时的 2 8 9eV增加到了 2 9 0eV ,其相对位移约为 0 1eV .

关键词：结合能单原子表面 x射线光电子能谱(x.s. 衬底相互作用性质研究生长模式覆盖度相对位移

Electron kinetic effects in back-stimulated Raman scattering bursts driven by broadband laser pulses

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Matter and Radiation at Extremes 2024年第4期9卷 54-67页

作者： Q.K.Liu L.Deng Q.wang x.Zhang F.Q.Meng Y.P.wang Y.Q.Gao H.B.Cai s.P.Zhu Graduate school China Academy of Engineering PhysicsBeijing 100088China Institute of Applied Physics and Computational Mathematics Beijing 100094China school of Nuclear science and Technology University of Science and Technology of ChinaHefei 230026China shanghai Institute of Laser Plasma Shanghai 201800China HEDPs Center for Applied Physics and TechnologyPeking UniversityBeijing 100871China school of Physics Zhejiang UniversityHangzhou 310027China

We examine electron kinetic effects in broadband-laser-driven back-stimulated Raman scattering(BsRs)bursts using particle-in-cell *** bursts occur during the nonlinear stage,causing reflectivity spikes and generating large numbers of hot ***-duration simulations are performed to observe burst events,and a simplified model is developed to eliminate the interference of the broadband laser’s random intensity *** the simplified model,we isolate and characterize the spectrum of electron plasma *** spectrum changes from a sideband structure to a turbulence-like structure during the burst.A significant asymmetry in the spectrum is *** asymmetry is amplified and transferred to electron phase space by high-intensity broadband laser pulses,leading to violent vortex-merging and generation of hot *** proportion of hot electrons increases from 6.76%to 14.7%during a single violent burst *** demonstrate that kinetic effects profoundly influence the BsRs evolution driven by broadband lasers.

关键词： scattering kinetic simplified

Facile fabrication of CdIn_(2)s_(4)/TiO_(2)heterojunction for enhanced solar light efficient CO_(2)reduction

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Frontiers of Chemical science and Engineering 2024年第9期18卷 101-112页

作者： xiaoyu Ma Longlong wang Houde she Yu Zhou Lei wang Jingwei Huang Qizhao wang College of Chemistry and Chemical Engineering Northwest Normal UniversityLanzhou 730070China school of Environment science and Engineering Chang’an UniversityXi’an 710064China

Photocatalytic CO_(2)reduction is a promising solution to simultaneously provide renewable chemical fuels and address the greenhouse ***,designing practical photocatalysts with advanced architectures remains ***,we report the preparation of a novel CdIn_(2)s_(4)/TiO_(2)binary heterojunction via an in situ solvothermal approach,which exhibits superior photocatalytic activity for sunlight-driven CO_(2)*** CdIn_(2)s_(4)/TiO_(2)composites exhibit significantly enhanced photocatalytic performance for CO_(2)reduction compared to unmodified TiO_(2).Among them,the 3%CdIn_(2)s_(4)/TiO_(2)composite has optimal CO and CH_(4) evolution rates of 18.32 and 1.03μmol·g–1·h–1,*** yield of CO is 4.7 times higher than that of pristine TiO_(2).This improved photocatalytic activity of the CdIn_(2)s_(4)/TiO_(2)heterostructure can be attributed to its large surface area,extended light absorption range and high separation efficiency of photogenerated electron-hole pairs,which are supported by the results of photoluminescence spectroscopy and the photoelectrochemical ***,the photocatalytic mechanism based on the binary CdIn_(2)s_(4)/TiO_(2)heterojunction is proposed and separation process of photogenerated electron-hole pairs is *** brief,we aim to provide insights into the application of TiO_(2)in energy conversion processes through the construction of heterogeneous junctions.

关键词： TiiO_(2) CdIn_(2)s_(4) heterojunction photocatalytic CiO_(2)reduction

How can technology and efficiency alleviate the dilemma of economic growth and carbon emissions in China's industrial economy? A metafrontier decoupling decomposition analysis

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Petroleum science 2024年第2期21卷 1415-1428页

作者： Miao wang Chao Feng school of Business Zhengzhou UniversityZhengzhou450001HenanChina school of Economics and Business Administration Chongqing UniversityChongqing400030China

This paper attempts to explore the decoupling relationship and its drivers between industrial economic increase and energy-related CO_(2) emissions(ICE). Firstly, the decoupling relationship was evaluated by Tapio index. Then, based on the DEA meta-frontier theory framework which taking into account the regional and industrial heterogeneity and index decomposition method, the driving factors of decoupling process were explored mainly from the view of technology and efficiency. The results show that during2000-2019, weak decoupling was the primary state. Investment scale expansion was the largest reason hindering decoupling process of industrial increase from ICE. Both energy saving and production technology achieved significant progress, which facilitated the decoupling process. simultaneously, the energy technology gap and production technology gap among regions have been narrowed, and played a role in promoting decoupling process. On the contrary, both scale economy efficiency and pure technical efficiency have inhibiting effects on decoupling process. The former indicates that the scale economy of China's industry was not conducive to improve energy efficiency and production efficiency, while the latter indicates that resource misallocation problem may ex.s. in both energy market and product market.

关键词： China's industrial sector Decoupling process Meta-frontier DEA Index decomposition method Driving factors