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Synthesis of Single-Crystal TiO_2 Nanowire Using Titanium Monoxide Powder by Thermal Evaporation

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Journal of Materials Science & Technology 2012年第5期28卷 385-390页

作者： Z.G.shang Z.q.Liu P.J.shang J.K.shang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

TiO 2 nanowires were synthesized successfully in a large quantity by thermal evaporation using titanium monoxide powder as precursor. X-ray diffraction results showed that all the products were pure rutile phase of TiO 2 . According to microstructural observations, the nanowires have two typical morphologies, a long straight type and a short tortuous type. The straight nanowires were obtained at a wide temperature range of 900–1050 ℃, while the tortuous ones were formed below 900 ℃. Transmission electron microscopy characterization revealed that both the straight and the tortuous nanowires are single-crystal rutile TiO 2 . The preferential growth direction of the nanowires was determined as [110] orientation according to electron diffraction and high-resolution image analyses. The morphological change of TiO 2 nanowires was discussed by considering the different atomic diffusion rates of Ti atoms caused by the phase transformation in Ti substrate at around 900 ℃.

关键词： Rutile-TiO 2 Alloy nanowires Transmission electron microscopy (TEM) characterization Crystal structure identification Growth mechanism Thermal evaporation

First-principles Investigation of Bi Segregation at the Solder Interface of Cu/Cu_3Sn(010)

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Journal of Materials Science & Technology 2010年第12期26卷 1057-1062页

作者： X.Y. Pang Z.q. Liu S.q. Wang J.K. shang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Department of Materials Science and Engineering University of Illinois at Urbana-Champaign IL 61801 USA

Density functional theory was employed to investigate the bismuth segregation at Cu/Cu3Sn（010） interface. Five initial constructions were introduced by adopting the adhesion energy criterion. Among them, the so-called ＂between-Cu＂ construction in which the interface Cu atoms of Cu slab locate along Cu-Cu bond direction in Cu3Sn slab was found to be the most energy-favored at an adhesion energy of 1.96 J/m^2. Based on this construction, five possible segregation sites were examined, and the most likely segregation site was determined with adhesion energy as low as 1.06 J/m^2, which was almost half of the initial one. Comparing with other sitest adhesion energies, it was concluded that size effect took a large part in embrittlement. The analyses of atomic structure and electronic density revealed that the slabs shifted away from interfaces due to bismuth segregation, and the atoms around Bi atom were Dressed away. This calculated work agreed aualitativelv with reported experimental results.

关键词： First-principles calculation Segregation Bismuth Interface SnBi solder

Effects of Current Stressing on Shear Properties of Sn-3.8Ag-0.7Cu Solder Joints

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Journal of Materials Science & Technology 2010年第8期26卷 737-742页

作者： X.J. Wang q.L. Zeng q.S. Zhu Z.G. Wang J.K. shang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Department of Materials Science and Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 USA

Effects of electromigration on microstructure, shear strength, and fracture behavior of solder joints were investigated by single-ball shear samples of eutectic Sn-3.8Ag-0.7Cu （SAC） joined by Cu plates at two sides. The electromigration tests were conducted at a current density of about 1.1×10^3 A/cm2 and a working temperature of about 83℃. The results showed that the shear strength and flow stress decreased greatly after current stressing. Such a decrease was associated with no significant loss of the fracture strain at short electromigration but a great reduction in the fracture strain after long-term current stressing. The variation of the fracture strain with the electromigration time was shown to result from the shift of the fracture surface from the center of the solder towards the intermetallic compound （IMC） interface at the cathode.

关键词： Strength Fracture strain Voids Solder

FORMATION OF GRADIENT COATING OF Fe-BASED ALLOY WITH RARE EARTHS BY PLASMA SURFACING

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Acta Metallurgica Sinica(English Letters) 2004年第5期17卷 713-718页

作者： L.J.shang A.q.Sun J.F.Chen C.M.Zhang q.K.Cai CollegeofMaterialsScienceandEngineering ShenyangPolytechnicUniversityShenyang110023China SchoolofMaterialsandMetallurgy NortheasternUniversityShenyang110004China

A gradient coating of Fe-based alloy was manufactured with rare earths (RE) by plasma surfacing on q235 steel substrate. The coatings were studied by using X-ray diffraction(XRD), scanning electron microscope(SEM), differential thermal analyzer(DTA), and electron probe micro-analyzer (EPMA). The results show that the phases of the two kinds of coatings(with and without RE) both include α-Fe, Fe7C3, Fe3C, Cr2B, Fe2B and FeB. The microstructure of F314 coating is mainly hypereutectic, the pro-phases Cr7C3 and Cr2B are loose, crassi, spiculate and contain microcracks. The brittleness of the coating is high, and the average hardness is 787 HV. When 0.8wt% RE was added into the F314 alloy, the microstructure varied from hypoeutectic to hypereutectic continuously, The hardness appears as gradient distribution with the highest value of 773 HV, meanwhile, the brittleness decreases significantly. The formation of gradient structure depends on the fallowing factors: (i) the conversion of RE. The addition of RE lowers the elements point and Fe-C eutectic temperature, thus the base metal melting acutely. (ii) the heating of plasma arc. Graded temperature results in directional solidification, thus the gradient structure forms easily. The main reasons for the hardness decrease with RE addition in the alloy are the ratio of hard phase lowering and the hardness of the hard phase decreasing.

关键词： rare earth plasma surfacing Fe-base alloy microstructure graded coating

Reduction effect of final-pass heavy reduction rolling on the texture development,tensile property and stretch formability of ZWK100 alloy plates

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Journal of Materials Science & Technology 2022年第16期111卷 211-223页

作者： B.q.Shi L.Y.Zhao X.L.shang B.H.Nie D.C.Chen C.q.Li Y.q.Cheng School of Materials Science and Hydrogen Energy Foshan UniversityFoshan 528000China School of Materials and Energy Guangdong University of TechnologyGuangzhouGuangdong 510006China GD Midea Air-Conditioning Equipment Co. Ltd.Foshan 528311China Guangdong Key Laboratory of Hydrogen Energy Technology Foshan 528000China YunFu(Foshan)R&D Center of Hydrogen Energy Standardization Yunfu 527326China

Obviously planar anisotropy due to‘TD split’orthotropic texture(TD indicates Transverse direction)always exist in the Rare-earth(RE)or Ca containing Mg alloy sheets,which is likely caused by the lowreduction rolling(and annealing)as revealed in our previous *** this work,the as-cast billets of a ZWK100 alloy were subjected to final-pass heavy reduction rolling(FHRR)at 500°C with different reductions(30%-70%)after rough rolling,aiming to investigate the reduction effect on the microstructure and texture *** results show that FHRR with higher reductions above 50%is in favor of shear banding formation but has little effect on the as-deformed texture components,and the excellent formability with single-pass reduction up to 70%is mainly ascribed to the activation of prismatic *** with reduction above 50%and annealing can generate uniform grain structures of~10μm and symmetrical‘oblique-line split’texture in(0001)pole figures,with basal poles tilting by about 50°from ND(Normal direction)towards some oblique-line of TD and RD(Rolling direction)as well as uniform distribution of counter lines as an annular shape,resulting in excellent elongation to failure of~50%and ultra-low planar anisotropyΔr_of~0.1 and high stretch formability(Erichsen value:8.1).The formation‘oblique-line split’texture in(0001)pole figures is mainly correlated with the preferred growth tendency of grains with■//RD,which was suggested to relate to the high mobility of some special boundaries such as 40°-45°■.The influences of starting textures on the mechanical properties,planar anisotropy and related deformation modes,as well as their correlations with the stretch formability were comparatively investigated with the‘TD split’orthotropic texture as a counterpoint.

关键词： Magnesium alloys Texture Plane anisotropy Stretch formability Rolled sheets

Interactive Image Enhancement by Fuzzy Relaxation

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International Journal of Automation and computing 2007年第3期4卷 229-235页

作者： shang-Ming Zhou John q.Can Li-Da Xu Robert John School of Computing De Montfort UniversityLeicester LE1 9BHUK Department of Computer Science University of EssexColchester CO3 4SQUK Department of Information Technology and Decision Sciences Old Dominion UniversityNorfolk VA23529-0218USA

In this paper, an interactive image enhancement （HE） technique based on fuzzy relaxation is presented, which allows the user to select different intensity levels for enhancement and intermit the enhancement process according to his/her preference in applications. First, based on an analysis of the convergence of a fuzzy relaxation algorithm for image contrast enhancement, an improved version of this algorithm, which is called FuzzIIE Method 1, is suggested by deriving a relationship between the convergence regions and the parameters in the transformations defined in the algorithm. Then a method called FuzzIIE Method 2 is introduced by using a different fuzzy relaxation function, in which there is no need to re-select the parameter values for interactive image enhancement. Experimental results are presented demonstrating the enhancement capabilities of the proposed methods under different conditions.

关键词： Interactive image enhancement fuzzy relaxation fuzzy set crossover point convergence.

New immune regulators of sciatic nerve regeneration?Lessons from the neighborhood

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Neural Regeneration Research 2024年第4期19卷 705-706页

作者： AndréL.Bombeiro Rodrigo G.q.Fernandes julie C.Ribot Instituto de Medicina Molecular João Lobo Antunes Faculdade de MedicinaUniversidade de LisboaLisbonPortugal

For decades,the immune system has been associated with host protection against infectious pathogens or tumors,while also contributing to ***,this paradigm is now changing,with recent studies highlighting novel roles for immune mediators in the maintenance of steady-state tissue *** this perspective,we review some of the latest findings featuring immune modulators of the nervous system pathophysiology,with a special focus on interleukin(IL)-17.

关键词： homeostasis neighborhood finding

Micro-sized and Nano-sized Fe_3O_4 Particles as Anode Materials for Lithium-ion Batteries

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Journal of Materials Science & Technology 2011年第1期27卷 41-45页

作者： Y.X.Chen L.H.He P.J.shang q.L.Tang Z.q.Liu H.B.Liu L.P.Zhou College of Materials Science and Engineering Hunan UniversityChangsha 410082China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Micro-sized（1030.3±178.4 nm） and nano-sized（50.4±8.0 nm） Fe3O4 particles have been fabricated through hydrogen thermal reduction of α-Fe2O3 particles synthesized by means of a hydrothermal *** morphology and microstructure of the micro-sized and the nano-sized Fe3O4 particles were characterized by X-ray diffraction,field-emission gun scanning electron microscopy,transmission electron microscopy and highresolution electron *** micro-sized Fe3O4 particles exhibit porous structure,while the nano-sized Fe3O4 particles are solid *** electrochemical performance was also *** nano-sized solid Fe3O4 particles exhibit gradual capacity fading with initial discharge capacity of 1083.1 mAhg-1 and reversible capacity retention of 32.6% over 50 ***,the micro-sized porous Fe3O4 particles display very stable capacity-cycling behavior,with initial discharge capacity of 887.5 mAhg-1 and charge capacity of 684.4 mAhg-1 at the 50th ***,77.1% of the reversible capacity can be maintained over 50 *** micro-sized porous Fe3O4 particles with facile synthesis,good cycling performance and high capacity retention are promising candidate as anode materials for high energy-density lithium-ion batteries.

关键词： Lithium-ion battery Fe3O4 Porous structure Anode materials

quantum query Complexity for Searching Multiple Marked States from an Unsorted Database

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Communications in Theoretical Physics 2007年第2X期48卷 264-266页

作者： shang Bin School of Computer Science & Technology Beijing Institute of Technology Beijing 100081 China

An important and usual sort of search problems is to find all marked states from an unsorted database with a large number of states. Grover＇s original quantum search algorithm is for finding single marked state with uncertainty, and it has been generalized to the case of multiple marked states, as well as been modified to find single marked state with certainty. However, the query complexity for finding all multiple marked states has not been addressed. We use a generalized Long＇s algorithm with high precision to solve such a problem. We calculate the approximate query complexity, which increases with the number of marked states and with the precision that we demand. In the end we introduce an algorithm for the problem on a ＂duality computer＂ and show its advantage over other algorithms.

关键词： quantum algorithm unsorted database search problem quantum query complexity