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An effective method for the hydrodehalogenation of organic halides

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Chinese Science Bulletin 1997年第11期42卷 966-967页

作者： Li, HQ Liao, SJ xu, y yu, DR Qiao, ZM CHINESE ACAD SCI DALIAN INST CHEM PHYSDALIAN 116023PEOPLES R CHINA

THE reduction of organic halides to the corresponding hydrocarbons plays an important role inorganic synthesis and environmental *** is one of the earliest reactions de-scribed in the organic chemical literature.A number of successful approaches have been report-ed hitherto,but the hydrodehalogenation of chloroarenes and organic fluorides is still a

关键词： An effective method for the hydrodehalogenation of organic halides

Effects of soil fauna on leaf litter decomposition under different land uses in eastern coast of China

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Journal of Forestry Research 2018年第4期29卷 968-977页

作者： Baoling yang Wenwen Zhang Hanmei xu Shaojun Wang Xia xu Huan Fan Han y. H. Chen Honghua Ruan Co-Innovation Center for Sustainable Forestry in Southern China College of Biology and the Environment Nanjing Forestry University Nanjing 210037 Jiangsu Province People's Republic of China School of Jiangsu Vocational College of Agriculture and Forestry Jurong 212400 People's Republic of China Shanghai Forestry Station Shanghai 200072 People's Republic of China College of Environment Science and Engineering Southwest Forestry University Kunming 650224 People's Republic of China Faculty of Natural Resources Management Lakehead University 955 Oliver Road Thunder Bay ON P7B 5E1 Canada

Soil fauna decompose litter, whereas land use changes may significantly alter the composition and structure of soil fauna assemblages. However, little is known of the effects of land-use on the contribution of soil fauna to litter decomposition. We studied the impacts of soil fauna on the decomposition of litter from poplar trees under three different land uses （i.e. poplar-crop integrated system, poplar plantation, and cropland）, from December 2013 to December 2014, in a coastal area of Northern Jiangsu Province. We collected litter samples in litterbags with three mesh sizes （5, 1 and 0. 01 mm, respectively） to quantify the contribution of various soil fauna to the decomposition of poplar leaf litter. Litter decomposition rates differed significantly by land use and were highest in the cropland, intermediate in the poplar-crop integrated system, and lowest in the poplar plantation. Soil fauna in the poplar-crop integrated system was characterized by the highest numbers of taxa and individuals, and highest Margalef＇s diversity, which suggested that agro-forestry ecosystems may support a greater quantity, distribution, and biodiversity of soil fauna than can single-species agriculture or plantation forestry. The individuals and groups of soil fauna in the macro-mesh litterbags were higher than in the meso-mesh litterbags underthe same land use types. The average contribution rate of meso- and micro-fauna to litter decomposition was 18.46%, which was higher than the contribution rate of macro-fauna （3.31%）. The percentage of remaining litter mass was inversely related to the density of the soil fauna （P 〈 0.05） in poplar plantations; however, was unrelated in the poplar-crop integrated system and cropland. This may have been the result of anthropogenic interference in poplar-crop integrated systems and croplands. Our study suggested that when land-use change alters vegetation types, it can affect species composition and the structure of soil fauna assemblages, which,

关键词： Mesh sizes Poplar Leaf litter Soil fauna Litter decomposition

Identifying Scientific and Technical“Unicorns”

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Journal of Data and Information Science 2021年第2期6卷 96-115页

作者： Lucy L.xu Miao Qi Fred y.ye Jiangsu Key Laboratory of Data Engineering and Knowledge Service School of Information ManagementNanjing UniversityNanjing 210023China University Library Nantong UniversityNantong 226019China

Purpose:Using the metaphor of"unicorn,"we identify the scientific papers and technical patents characterized by the informetric feature of very high citations in the first ten years after publishing,which may provide a new pattern to understand very high impact works in science and ***/methodology/approach:When we set CT as the total citations of papers or patents in the first ten years after publication,with CT≥5,000 for scientific"unicorn"and CT≥500 for technical"unicorn,"we have an absolute standard for identifying scientific and technical"unicorn"***:We identify 165 scientific"unicorns"in 14,301,875 WoS papers and 224 technical"unicorns"in 13,728,950 DII patents during 2001–*** 50%of"unicorns"belong to biomedicine,in which selected cases are individually *** rare"unicorns"increase following linear model,the fitting data show 95%confidence with the RMSE of scientific"unicorn"is 0.2127 while the RMSE of technical"unicorn"is *** limitations:A"unicorn"is a pure quantitative consideration without concerning its quality,and"potential unicorns"as CT≤5,000 for papers and CT≤500 for patents are left in future *** implications:Scientific and technical"unicorns"provide a new pattern to understand high-impact works in science and ***"unicorn"pattern supplies a concise approach to identify very high-impact scientific papers and technical ***/value:The"unicorn"pattern supplies a concise approach to identify very high impact scientific papers and technical patents.

关键词： Unicorn Scientific paper Technical patent Citation analysis Patent analysis

Nanometer scale patterning of ultrathin films with a scanning tunneling microscope in ambient environment

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仪器仪表学报 1995年第S1期16卷 211-216页

作者： xu Duan-yi xu,Ling-song(TSINGHUA UNIVERSITy UNIVERSI7y OF ARIZONA)

ＮａｎｏｍｅｔｅｒｓｃａｌｅｐａｔｔｅｒｎｉｎｇｏｆｕｌｔｒａｔｈｉｎｆｉｌｍｓｗｉｔｈａｓｃａｎｎｉｎｇｔｕｎｎｅｌｉｎｇｍｉｃｒｏｓｃｏｐｅｉｎａｍｂｉｅｎｔｅｎｖｉｒｏｎｍｅｎｔＮａｎｏｍｅｔｅｒｓｃａｌｅｐａ... 详细信息

ＮａｎｏｍｅｔｅｒｓｃａｌｅｐａｔｔｅｒｎｉｎｇｏｆｕｌｔｒａｔｈｉｎｆｉｌｍｓｗｉｔｈａｓｃａｎｎｉｎｇｔｕｎｎｅｌｉｎｇｍｉｃｒｏｓｃｏｐｅｉｎａｍｂｉｅｎｔｅｎｖｉｒｏｎｍｅｎｔＮａｎｏｍｅｔｅｒｓｃａｌｅｐａｔｔｅｒｎｉｎｇｏｆｕｌｔｒａｔｈ...

关键词： patterning films ultrathin

NUMERICAL SIMULATION OF CONTROLLING IN TITANIUM ALLOy SHEETS WELDING RESIDUAL STRESS By TRAILING PEENING

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 311-316页

作者： X.S.Liu H.y.Fang W.L.xu Z.B.Dong D.y.yu State Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China

It is a promising and new technology to apply welding with trailing peening to control welding stress and distortion of titanium *** simulation of conventional welding and welding with trailing peening of the titanium alloy sheet is carried out,using nonlinear finite element theory and the engineering analysis software *** result shows that welding with trailing peening technology reduces longitudinal residual stress in welding joint effectively,and it is more effective to reduce residual stress to peen the weld than to peen the weld *** is a effective result that other technology and method used in welding can never achieved.

关键词： numerical simulation residual stress and distortion welding with trailing peening titanium alloy

Inhibiting effect of I-phase formation on the plastic instability of the duplex structured Mg-8Li-6Zn-1.2y(in wt.%)alloy

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Journal of Magnesium and Alloys 2023年第6期11卷 2196-2204页

作者： B.J.Wang D.K.xu X.Q.Zhuang L.y.Sheng School of Environmental and Chemical Engineering Shenyang Ligong UniversityShenyang110159China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Peking University Shenzhen InstituteShenzhen Key Lab Human Tissue Regenerate&RepairShenzhen 518057China

In this work,the tensile behaviors of Mg-8%Li and Mg-8%Li-6%Zn-1.2%y alloys at ambient temperature were investigated and *** revealed that the plastic instability of Mg-8%Li alloy was quite remarkable and the variation range of serrated flowing stress can reach5 *** the Mg-8%Li-6%Zn-1.2%y alloy,the formation of I-phase(Mg_(3)Zn_(6)y)can simultaneously enhance the tensile strength and eliminate the plastic instability phenomenon,whilst its ductility was *** in-situ tensile tests revealed that for the Mg-8%Li alloy,the severity and number of slip traces present in bothα-Mg andβ-Li matrix phases increased remarkably with the applied tensile ***,slip traces were quite fine inβ-Li matrix phase and could be clearly observed when the applied tensile strain exceeded 18%.Due to the incompatibility of plastic deformation occurred in two matrix phases,the induced strain concentration atα-Mg/β-Li interfaces caused their subsequent *** the Mg-8%-6%Zn-1.2%y alloy,the I-phase distributed atα-Mg/β-Li interfaces suppressed the plastic deformation ofα-Mg matrix phase and the tensile strain was dominated by theβ-Li matrix phase,resulting in the disappearance of plastic ***,the plastic strain would preferentially concentrate at I-phase/β-Li interfaces and subsequently induced the cracking of I-phase.

关键词： Mg-li alloys Microstructure Plastic deformation Basal slip Cracking

Solid-state alloying of Al-Mg alloys by accumulative roll-bonding:Microstructure and properties

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Journal of Materials Science & Technology 2022年第30期125卷 238-251页

作者： X.M.Mei Q.S.Mei J.y.Li C.L.Li L.Wan F.Chen Z.H.Chen T.xu y.C.Wang y.y.Tan School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China Key Laboratory of Hydraulic Machinery Transients(Wuhan University) Ministry of EducationWuhan 430072China School of Mechanical Engineering Wuhan Polytechnic UniversityWuhan 430023China

In this study,a novel solid-state alloying approach was adopted to fabricate Al-Mg alloys with high Mg contents(C_(Mg)) by accumulative roll-bonding(ARB)of Al and Mg elemental materials to ultrahigh *** results showed that the degree of alloying increased with the increase of ARB cycles and a supersaturatedα-Al solid solution accompanied with nanoprecipitates was formed in the Al-Mg alloys by ARB to 70 *** as-prepared Al-Mg alloys exhibited enhanced mechanical properties,with a maximum tensile strength of∼615 MPa and a tensile elongation of∼10%at C_(Mg)=13 wt.%.The high strength can be attributed to different mechanisms,namely solid solution strengthening,grain boundary strengthening,dislocation strengthening,and precipitation *** Al-Mg alloys showed increased work hardening with increasing C_(Mg),due to the enhanced formation of ***,no obvious drop in the intergranular corrosion(IGC)resistance was found in the Al-Mg alloys with C_(Mg) up to 13 wt.%.Moreover,sensitization treatment was found to induce little decrease in the IGC resistance of the Al-Mg alloys with C_(Mg)≤13 wt.%.We found that the excellent IGC resistance was due to the suppression of grain boundary precipitation by the preferred formation of precipitates within the grains that were induced by *** study indicated the novelty of the present solid-state alloying approach to achieving a superior combination of high mechanical properties and IGC resistance in Al-Mg alloys.

关键词： Solid-state alloying Al-Mg alloys Mechanical properties IGC resistance ARB

Corrosion and cavitation erosion resistance enhancement of cast Ni–Al bronze by laser surface melting

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Journal of Iron and Steel Research International 2022年第2期29卷 359-369页

作者： Q.N.Song y.Tong H.L.Li H.N.Zhang N.xu G.y.Zhang y.F.Bao W.Liu Z.G.Liu y.X.Qiao Engineering Research Center of Dredging Technology of Ministry of Education Hohai UniversityChangzhou213022JiangsuChina College of Mechanical and Electrical Engineering Hohai UniversityChangzhou213022JiangsuChina College of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212003JiangsuChina

Laser surface melting (LSM) was applied on a cast Ni–Al bronze (NAB), which was a crucial material for marine ship propellers. A 720 μm-thick LSM layer with fine equiaxed and dendritic microstructures was obtained. After immersion for 30 days, the corrosion rate of cast NAB was reduced by 25% after LSM. Preferential corrosion occurred and deep corrosion pits appeared at α + κIII microstructure for the cast NAB. LSM NAB underwent general corrosion, and a much more protective film formed on the surface because of the homogenized microstructure. The mass loss of the cast NAB was approximately 2.1 times larger than that of LSM NAB after cavitation erosion (CE) in 3.5 wt.% NaCl solution for 5 h. For the two materials, the mechanical impact effect was dominantly responsible for CE damage. Therefore, the improved hardness and homogenized microstructure contributed to the improved CE resistance of LSM NAB. CE destructed the film, shifted the open circuit potential toward a more negative value, and raised the current density by an order of magnitude. Corrosion at the cast eutectoid microstructure and the dendrites of LSM NAB facilitates the degradation under the cavitation attack. CE-corrosion synergy was largely caused by corrosion-enhanced-CE.

关键词： Laser surface melting Ni-Al bronze Microstructure Corrosion Cavitation erosion Synergy

Microstructural characteristics and mechanical properties of the hot extruded Mg-Zn-y-Nd alloys

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Journal of Materials Science & Technology 2021年第1期60卷 44-55页

作者： B.N.Du Z.y.Hu L.y.Sheng D.K.xu y.X.Qiao B.J.Wang J.Wang y.F.Zheng T.F.Xi Shenzhen Institute Peking UniversityShenzhen 518057China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Jiangsu University of Science and Technology Zhenjiang 212003China Shenzhen yezhan Electronics Co. LtdShenzhen 518110China

A new type of Mg-Zn-y-Nd alloy for degradable orthopedic implants was *** the present study,the Zn and y content was adjusted and their influences on the microstructures and mechanical behaviors were discussed in *** results showed that the as-extruded Mg-Zn-y-Nd alloys are mainly composed of fine dynamic recrystallized grains(DRXed grains),la rge unDRXed grains and linearly distributed secondary *** cha nge of Zn content exerts little influence on the grain structure of the extruded Mg-Zn-y-Nd alloy,while the increase of y content would hinder the dynamic recrystallization process and the growth of the DRXed grains,thus the size and volume fraction of the equiaxed DRXed grains *** tensile and compressive properties are very little affected by Zn content because of the similar grain *** y content increases,the tensile yield strength(TyS) and ultimate strength(TUS) increase while the elongation decreases,this is caused by a combined strengthening effect of grain refinement,texture,precipitation and *** compressive yield strength(CyS) and ultimate strength(CUS) of Mg-Zn-y-Nd alloy with diffe rent y content exhibit a similar tendency as the tensile test.

关键词： Mg-Zn-y-Nd alloy Microstructure Tensile properties Compressive properties Basal texture Twin