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Exact solutions for unsteady unidirectional flows of a generalized second-order fluid through a rectangular conduit

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Acta mechanica Sinica 2009年第2期25卷 181-186页

作者： J. Kang m. xu School of mathematics, Institute of Applied mathematics,Shandong University, 250100 Jinan, China m. xu School of mathematics Institute of Applied Mathematics Shandong University Jinan China

The exact solutions are obtained for unsteady unidirectional flows of a generalized second-order fluid through a rectangular conduit. The fractional calculus in the constitutive relationship of a non-Newtonian fluid is introduced. We construct the solutions by means of Fourier transform and the discrete Laplace transform of the sequential derivatives and the double finite Fourier transform. The solutions for Newtonian fluid between two infinite parallel plates appear as limiting cases of our solutions.

关键词： Generalized second-order fluid - Rectangularconduit Fractional calculus Exact solutions

The Electronic Structures of Dimeric Diboroxane and Aldiminoborane

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Chemical Research in Chinese Universities 1995年第3期11卷 232-237页

作者： WANG, ZZ xu, m YANG, ZZ JILIN UNIV INST THEORET CHEMCHANGCHUN 130023PEOPLES R CHINA JILIN UNIV NATL LAB THEORET & COMPUTAT CHEMCHANGCHUN 130023PEOPLES R CHINA

e have studied the electronic structures of dimeric diboroxane and aldiminob-orane by nieans of STO-3G .ib iuitio SCF method. The energies and the componentanalysis of niolecular orbitals near to frontier orbital have been given. By bothKoopman' s theoreni and △E_(scf)mietliod we have calculated the ionization potentialsof 8 higlier occupied orbitals and discussed the electron relaxation effect on IP' s cal-culations and the charge distribuuons for the two molecules.

关键词： Diboroxane Aldiniuioborane ab initio SCF method

Study on Coastal Protection Engineering in the Area of Abandoned Yellow River mouth

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China Ocean Engineering 1998年第2期13卷 223-234页

作者： Zhang, YF Yu, GH Sheng, ZC xu, m Nanjing Hydraul Res Inst River & Harbour Dept Nanjing 210024 Peoples R China

This paper reviews the history of coast evolution and coastal protection in the area of the abandoned Yellow River mouth in Jiangsu Province, analyzes the erosion characteristics and dynamic environment, evaluates the efficiency of coastal protection engineering works and designs the dimensions of the main seadike and offshore submerged dam. A gerneral scheme of shore protection for this area is proposed.

关键词： coastal protection coastal erosion wave calculation main seadike groin offshore submerged dam

HIGHLY DISPERSED mULTI-WALLED CARBON NANOTUBES IN WATER/ETHANOL AND ITS APPLICATION FOR PVA COmPOSITE

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Acta metallurgica Sinica(English Letters) 2005年第3期18卷 389-396页

作者： X.Y.Tao J.m.xu F.Liu G.L.xu InstituteofmaterialsPhysicsandmicrostructures DepartmentofMaterialsScienceandEngmeeringZhejiangUniversityHangzhou310027China CollegeofElectronicInformation HangzhouDianziUniversityHangzhou310018China

Two carboxylation processes were carried out to modify multi-walled carbon nanot ube bundles (m-mWNTs). The results showed that both of the m-mWNTs could be high ly dispersed in water with the concentration up to 25 and 15mg/mL in ethanol wit hout obvious deposition or conglomeration over 6 months. FTIR, Raman, TGA and TE m characterizations of the m- mWNTs showed that hydroxyl and carboxyl groups hav e been attached with mWNTs, and that the nanotube structure was only damaged a l ittle after modification treatments in mixed acids over 24h. Above prepared nano tube suspensions in water were successfully used as a filler of thermoplastic PV A composite to enhance its electrical conductivity. The results showed that the addition of m-mWNTs greatly improved the conductivity and the threshold of mass fraction was about 5wt%. The results also proved that purification process was n ot needed because of high purity of the raw mWNTs prepared in our group.

关键词： carbon nanotube polyvinylalcohol composite conductivity

RELATIONSHIP　BETWEEN　STRUCTURE　AND　SHAPE　mEmORY　EFFECT　OF　SEGmENTED　POLYURETHANES

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Chinese Chemical Letters 1996年第8期7卷 756-758页

作者： Li, FK Zhang, X xu, m Luo, XL ACAD SINICA INST CHEMPOLYMER PHYS LABBEIJING 100080PEOPLES R CHINA UNIV SCI & TECHNOL CHINA DEPT MAT SCIHEFEI 230026PEOPLES R CHINA

The shape memory behavior of a series of PCL/mEI/BDO segmentedpolyurethanes of different composition is presented. The molecular weight of the PCLdids is in the range of 1600-7000. It is found that the shape memory effect ofsegmented polyurethanes is really related with the crystallinity of the soft segmentregions and the formation of stable hard segment domains as predicted by the modelproposed in our previous papers.

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3-D QSAR study on a set of nitroaromatic compounds

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Chinese Science Bulletin 2002年第3期47卷 189-193页

作者： xu, m Zhang, AQ Han, SK Wang, LS Nanjing Univ Sch Environm State Key Lab Pollut Control & Resource Reuse Nanjing 210093 Peoples R China

The 3-D relationships between the structures of 25 nitroaromatic compounds and their toxicities have been investigated using the comparative molecular field analysis (ComFA) method, and a 3-D QSAR model with considerable prediction ability is obtained. In comparison with traditional 2-D techniques, ComFA helps to give a better interpretation of toxic mechanism of tested compounds.

关键词： nitroaromatic compound 3-D QSAR ComFA.

Improving cyclic oxidation resistance of Ni_(3)Al-based single crystal superalloy with low-diffusion platinum-modified aluminide coating

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Journal of materials Science & Technology 2020年第19期54卷 132-143页

作者： H.Liu m.m.xu S.Li Z.B.Bao S.L.Zhu F.H.Wang Institute of metal Research Chinese Academy of SciencesWencui Road 62#Shenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaJinzhai Road 96#Hefei 230026China Shenyang National Laboratory for materials Science Northeastern UniversityWenhua Road 3#Shenyang 110819China

A low-diffusion Ni Re Pt Al coating((Ni,Pt)Al outer layer in addition to a Re-rich diffusion barrier layer)was prepared on a Ni_(3)Al-base single crystal(SC)superalloy via electroplating and gaseous aluminizing treatments,wherein the electroplating procedures consisted of the composite deposition of Ni-Re followed by electroplating of *** order to perform a comparison with conventional Ni Al and(Ni,Pt)Al coatings,the cyclic oxidation performance of the Ni Re Pt Al coating was evaluated at 1100 and 1150℃.We observed that the oxidation resistance of the Ni Re Pt Al coating was significantly improved by the greater presence of the residualβ-Ni Al phase in the outer layer and the lesser outward-diffusion of mo from the *** addition,the coating with the Re-rich diffusion barrier demonstrated a lower extent of interdiffusion into the substrate,where the thickness of the second reaction zone(SRZ)in the substrate alloy decreased by 25%.The mechanisms responsible for improving the oxidation resistance and decreasing the extent of SRZ formation are discussed,in which a particular attention is paid to the inhibition of the outward diffusion of mo by the Re-based diffusion barrier.

关键词： Ni_(3)Al-base superalloy Pt-modified aluminide coating Re-rich diffusion barrier Cyclic oxidation Interdiffusion Second reaction zone

Temperature Effect on Early Oxidation Behavior of NiCoCrAlY Coatings: microstructure and Phase Transformation

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Acta metallurgica Sinica(English Letters) 2022年第6期35卷 975-984页

作者： A.Ullah A.Khan Z.B.Bao Y.F.Yang m.m.xu S.L.Zhu F.H.Wang University of Chinese Academy of Sciences Beijing 100049China Shi-Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of Green Fabrication and Surface Technology of Advanced metal materials Ministry of EducationSchool of Materials Science and EngineeringAnhui University of TechnologyMaanshan 243000China Institute of Advanced Wear and Corrosion Resistant and Functional material Jinan UniversityGuangzhou 510632China Shenyang National Laboratory for materials Science Northeastern UniversityShenyang 110819China

Initial oxidation behavior of NiCoCrAlY coating prepared by arc-ion plating has been studied in air at 900, 1000 and 1100 ℃. The results showed that phase transformation from transient θ-Al_(2)O_(3) to α-Al_(2)O_(3) was highly related to the temperature and oxidation time. The oxide scale in the initial stage was mainly composed of θ-Al_(2)O_(3) at 900 ℃. Instead, more amount of α-Al_(2)O_(3) emerged out with increasing oxidation temperature. The elemental distribution after oxidation confirmed that faster chromium diffusion to the oxide scale played an important role in the speedy transformation from θ-Al_(2)O_(3) to α-Al_(2)O_(3). Y segregation at scale/coating interface resulted in less cavity formation and hence improved the oxide scale adherence.

关键词： mCrAlY coating Phase transformation Isothermal oxidation Temperature effect

Optimal Coordination of Transportable Power Sources and Repair Crews for Service Restoration of Distribution Networks Considering Uncertainty of Traffic Congestion

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Journal of modern Power Systems and Clean Energy 2024年第1期12卷 189-201页

作者： Zhao Shi Yan xu Dunjian Xie Shiwei Xie Amer m.Y.m.Ghias Nanyang Technological University Singapore the School of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108China

This paper proposes a new method for service restoration of distribution network with the support of transportable power sources(TPSs)and repair crews(RCs).Firstly,a coupling model of distribution networks and vehicle routing of TPSs and RCs is proposed,where the TPSs serve as emergency power supply sources,and the RCs are used to repair the faulted *** the uncertainty of traffic congestion,the probability distribution of the travel time spent on each road is derived based on the Nesterov user equilibrium model,and a two-stage stochastic program is formulated to determine the optimal routings of TPSs and *** efficiently solve the proposed stochastic mixed-integer linear program(mILP),a two-phase scenario reduction method is then developed to scale down the problem size,and an adaptive progressive hedging algorithm is used for an efficient *** effectiveness of the proposed methods and algorithms has been illustrated in a modified IEEE 33-bus system.

关键词： Service restoration distribution network traffic uncertainty transportable power source repair crew stochastic program