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Nanocrystal Model for liquid Metals and Amorphous Metals

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Journal of Materials Science & Technology 2010年第1期26卷 69-74页

作者： x.l. Tian, C.W. Zhan, J.x. Hou, x.C. Chen and J.J. Sun Key laboratory of liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061, China Key laboratory of liquid Structure and Heredity of Materials Ministry of Education Shandong University Jinan 250061 China

A nanocrystal model for liquid metals and amorphous metals has been developed. With the nanocrystal model, the broadening peak profiles （BPPs） of Cu, Al, Al65Cu20Fe15 alloy, Cu7oNi30 alloy and Fe50Si50 alloy were gained by broadening the x-ray diffraction （xRD） peaks of a crystal lattice. By comparing the BPPs with the xRD intensity curves measured on the liquid metals, it is found that the BPPs are closely in agreement with the xRD intensity curves, respectively, except the FesoSiso alloy. Therefore, the nanocrystal model can be used to determine if the atomic cluster structure of the liquid metal is similar to the structure of its crystal lattice.

关键词： liquid metal Atomic cluster Structure Crystal lattice

NON-EQUIlIBRIUM SOlUTE SEGREGATION TO AUSTENITIC GRAIN BOUNDARY IN FERRUM-NICKlE AllOY

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Acta Metallurgica Sinica(English letters) 2001年第6期14卷 525-531页

作者： P. Wu, D.Y. Yu and x.l. He (Department of Material Physics, University of Science & Technology Beijing, Beijing 100083, China) Dept. of Mat. Phys. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The development of non-equilibrium segregation of boron at grain boundaries in Fe-4 0%Ni alloy during continuous cooling process was experimentally observed with boron Particle Tracking Autoradiography (PTA) and Transmission Electron Microscopy (TEM,). The samples with 10ppm boron were cooled at 2℃/s to 1040, 980, 920, 860, 780 and 640℃ respectively after pre-heat treatment of 1150℃ for 15mm with a Gleeble-1500 heat simulating machine, then water quenched to room temperature. The width of segregation layer and boron depletion zone, rich factor and other parameters were measured by a special image analysis system. The experimental results of PTA show that the grain boundary segregation of boron during cooling process is a dynamic process and the development of the non-equilibrium segregation experiences three stages: first increases rapidly from 1150 to 1040℃, then gently from 1040 to 860℃, and rapidly again from 860℃ to 640℃. The width of boron depletion zone increases from about 11μm at 1040℃ to 26μm at 640℃. TEM observation shows that boron precipitates exist at grain boundaries when the samples are cooled to below 860℃. The experimental phenomena are briefly discussed.

关键词： boron grain boundary non-equilibrium segregation

THElATTICE STRAIN CAUSED BY ION IMPlANTATION

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Acta Metallurgica Sinica(English letters) 1999年第4期12卷 495-499页

作者： D.l. Ma and x.l. Mu Departmentof Physics,liaoning University,Shenyang 110036 ,China

The propertiesof As+ implantedsilicon with anenergy160kev, differentdosesand anneal ing temperatures (500 700℃) were studied by means of x ray double crystaldiffraction( DCD) and ellipometricspectra ( ES) . Therockingcurvesof DCDweresimulated by multi layer modelof Dynamicaltheory,toobtainstrain distributionsasafunctionof depths. The1×1016 cm 2 annealed at600℃wasfoundthataepitaxiallayer wasformed . The ESresult provedtheseconclusions.

关键词： THElATTICE STRAIN CAUSED BY ION IMPlANTATION

Spalling characteristics of high-temperature treated granitic rock at different strain rates

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： l.F.Fan Q.H.Yang x.l.Du The Key laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spalling characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spalling characteristics of granite with different temperatures and strain rates.A series of dynamic spalling tests with different impact velocities were conducted on thermally treated granite at different *** dynamic spalling strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spalling strength of granite,high temperature and strain *** results show that the spalling strength of granite decreases with increasing ***,the spalling strength of granite with a higher strain rate is larger than that with a lower strain *** proposed model can describe the relationship among dynamic spalling strength of granite,high temperature and strain rate.

关键词： Dynamic spalling characteristics High temperature Strain rate Dynamic loading Granite

DIFFERENTIAl SCANNING CAlORIMETRY AND x-RAY DIFFRACTION STUDIES ON AGING BEHAVIOR OF Zn-Al AllOYS

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Acta Metallurgica Sinica(English letters) 2001年第2期14卷 109-114页

作者： x.l. xu, Z. W. Yu, S.J. Ji, J.C. Sun and Z.K. Hei (Dalian Maritime University, Dalian 116024, China) Dalian Maritime Univ. Dalian 116024 China

Decomposition processes of the quenched Zn-Al alloys were studied by differential scanning calorimetry (DSC), x-ray diffraction (xRD) and transmission electron microscopy (TEM). The results show that the stabilities of supersaturated solid solution (SSS) of Zn-Al alloy and α' phase formed by quenching would reduce with the increase of Zn content and the precipitation of η-Zn phases even when aging at ambient temperature, so that the exothermic precipitation peak in DSC curve would disappear. The activation energy of the η-Zn precipitation and the reaction enthalpy were calculated and measured. The kinetics of α' decomposition or η-Zn formation was determined by xRD. The microstructure change during aging was observed by TEM.

关键词： Aging of materials Aluminum alloys Differential scanning calorimetry x ray diffraction

In situ TEM investigation of electron irradiation and aging-induced high-density nanoprecipitates in an Mg-10Gd-3Y-1Zn-0.5Zr alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1841-1853页

作者： M.lv H.l.Ge Q.Q.Jin x.H.Shao Y.T.Zhou B.Zhang x.l.Ma Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Materials Science and Engineering Research Center Guangxi University of Science and TechnologyLiuzhou 545006China

In-situ electron irradiation and aging are applied to introduce high-density precipitates in an Mg-10Gd-3Y-1Zn-0.5Zr(GWZ1031K,wt.%)alloy to improve the *** results show that the hardness of the Mg alloy after irradiation for 10 h and aging for 9 h at 250℃ is 1.64 GPa,which is approximately 64% higher than that of the samples before being *** is mainly attributed to γ'precipitates on the basal plane after irradiation and the high-density nanoscale β'precipitates on the prismatic plane after aging,which should be closely related to the irradiation-induced homogenous *** latter plays a key role in precipitation *** result paves a way to improve the mechanical properties of metallic materials by tailoring the precipitation through irradiation and aging.

关键词： Mg alloy Electron beam irradiation Hardening Precipitates In-situ TEM

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

Mapping Sea level Rise Behavior in an Estuarine Delta System：A Case Study along the Shanghai Coast

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Engineering 2018年第1期4卷 156-163页

作者： H.Q. Cheng J.Y. Chen Z.J. Chen R.l. Ruan G.Q. xu G. Zeng J.R. Zhu Z.J. Dai x.Y. Chen S.H. Gu x.l. Zhang H.M. Wang State Key laboratory of Estuarine and Coastal Research East China Normal University Shanghai 200062 China Shanghai Water Planning Design and Research Institute Shanghai 200232 China Shanghai Water Authority Shanghai 200050 China School of Urban and Regional Science East China Normal University Shanghai 200062 China School of Ecological and Environmental Sciences East China Normal University Shanghai 200062 China Shanghai Hydrological Station Shanghai 200232 China Shanghai Municipal Bureau of Urban Planning and land Resources Shanghai 200003 China Shanghai Institute of Geological Survey Shanghai 200072 China

Sea level rise (SlR) is a major projected threat of climate change that is expected to affect developing coastal cities located in estuarine delta regions. Shanghai is one such city, being located in the Yangtze River Delta (YRD). It is difficult, however, for decision-makers to implement adaptation due to the uncertain causes, magnitudes, and timings of SlR behaviors. This paper attempts to map the causes and magnitudes of SlR behaviors on a decadal scale. We analyze the tidal level records from 11 tidal gauge stations and the corresponding bathymetry measurements around these stations since 1921. We identify three new SlR behaviors along the Shanghai coast due to anthropogenic geomorphologic changes (AGCs), besides the well-known eustatic sea level rise (ESlR), tectonic subsidence (TS), and urban land subsidence (UlS). The first new behavior is regional sea level rise (RSlR), which occurs as a result of land reclamation and deep waterway regulation. The second is regional sea level fall (RSlF), which occurs because the channel bed is eroded due to sediment supply decline in the river catchment. The last SlR behavior is local tidal datum rise (lTDR). Thus, we project that the magnitude of SlR for the Shanghai coast ranges from 10 cm to 16 cm from 2011 to 2030. Clarifying SlR behaviors is important to aid local decisionmakers in planning structural and non-structural measures to combat escalating flood damage costs in an estuarine delta system; this field is full of future challenges.

关键词： Sea level rise behavior Anthropogenic geomorphologic change local tidal datum Flood management Adaptation

Four late-type Galaxies with Double Radio lobes and Properties of Such Galaxies

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Research in Astronomy and Astrophysics 2024年第4期24卷 84-90页

作者： Z.S.Yuan x.Y.Gao Z.l.Wen J.l.Han National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

The triggering mechanism for radio lobes from late-type galaxies is not fully *** samples are desired for a thorough investigation and *** utilizing the optical data from the newly released Dark Energy Spectroscopic Instrument imaging surveys and the radio sources from the NRAO VlA Sky Survey and the Faint Images of the Radio Sky at Twenty-centimeter,we identify four late-type Galaxies with double Radio lobes(la GRls):J0217-3645,J0947+6220,J1412+3723 and J1736+*** previously known la GRls,we confirm the correlation between radio power P_(1.4GHz)and stellar mass M_(*)of host ***(25/35)la GRls belong to the blue cloud galaxies,while the newly identified cases in this work are located within the region of the red *** find a clear correlation between the differential radio power,i.e.,the offset from the P_(1.4GHz)-M_(*)relation,and the galaxy color,indicating that bluer galaxies at a fixed M_(*)tend to host more powerful radio ***,the majority(31/36)of la GRls are either located in a galaxy group or displaying a disturbed *** suggest that all of the galaxy mass,color and surrounding environment could play important roles in triggering radio lobes in late-type galaxies.

关键词： galaxies:active galaxies:jets galaxies:spiral radio continuum:galaxies