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Quantum-Mechanical Study of Small Au2Pdn （n=1 ～ 4） Clusters

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Communications in Theoretical Physics 2006年第1X期46卷 155-160页

作者： guo jian-Jun yang Ji-Xian DIE Dong Institute of Applied Physics Xihua University Chengdu 610039 China

Gold-doped palladium clusters, Au2Pdn （n=1～4）, are investigated using the density functional method B3LYP with relativistic effective core potentials （RECP） and LANL2DZ basis set. The possible geometrical configurations with their electronic states are determined, and the stability trend is investigated. Several low-lying isomers are determined, and many of them are in electronic configurations with a high-spin multiplicity. Our results indicate that the palladium-gold interaction is strong enough to modify the known pattern of bare palladium clusters, and the lower stability as the structures grow in size. The present calculations are useful to understanding the enhanced catalytic activity and selectivity gained by using gold-doped palladium catalyst.

关键词： Au-Pd clusters geometrical configuration density functional method

Non-linear relationship between combustion kinetic parameters and coal quality

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第5期13卷 344-352页

作者： jian-guo yang Xiao-long ZHANG Hong ZHAO Li SHEN State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

Combustion kinetic parameters(i.e.,activation energy and frequency factor) of coal have been proven to relate closely to coal properties;however,the quantitative relationship between them still requires further *** paper adopts a support vector regression machine(SVR) to generate the models of the non-linear relationship between combustion kinetic parameters and coal *** analyses on the thermo-gravimetry(TG) data of 80 coal samples were performed to prepare training data and testing data for the *** models developed were used in the estimation of the combustion kinetic parameters of ten testing *** predicted results showed that the root mean square errors(RMSEs) were 2.571 for the activation energy and 0.565 for the frequency factor in logarithmic form,*** curves defined by predicted kinetic parameters were fitted to the experimental data with a high degree of precision.

关键词： Kinetic parameter Coal property Thermo-gravimetry(TG) Support vector regression machine(SVR) Differential evolution

First Principle Calculation on AunAg2 （n = 1 - 4） Clusters

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Communications in Theoretical Physics 2007年第2X期48卷 348-352页

作者： guo jian-Jun yang Ji-Xian DIE Dong School of Physics and Chemistry Xihua University Chengdu 610039 China

The first-principles method based on density-functional theory is used to investigate the geometries of the lowest-lying isomers of AunAg2 （n = 1 - 4） clusters. Several low-lying isomers are determined, and many of them in electronic configurations with a high spin multiplicity. The stability trend of Ag-doped Aun dusters is compared to that of pure Aun clusters. Our results indicate that the inclusion of two Ag atoms in the clusters lowers the cluster stability, indicating higher stability as the structures grow in size. The bigger energy difference between the Aun and AunAg2 curves as the structures grows in size. This information will be useful to understanding the enhanced catalytic activity and selectivity gained by using silver-doped gold catalyst.

关键词： first-principle calculation geometrical configuration Au-Ag clusters bimetallic clusters

Mechanism of Zr in in situ-synthesized particle reinforced composite coatings by laser cladding

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Rare Metals 2017年第12期36卷 934-941页

作者： Yao-Wei Yong Wei Fu Qi-Lin Deng jian-guo yang School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China School of Mechanical Engineering Ningxia UniversityYinchuan 750021 China State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Harbin 150080 China

By adding mixture of ZrOand carbon, a Zrenhanced composite coating was produced onto an AISI1045 substrate by laser cladding. The microstructure and phase formation, microhardness and wear resistance of the composite coating were studied. The experimental results indicate that the composite coating with metallurgical bonding to substrate consists of y-Ni, massive ceramic particles of ZrC,NiZr, NiZr,(Fe,Ni)Cand FeC. The in situ-synthesized ZrC particles are uniformly dispersed in composite coating, which refines the microstructure of composite coating. With different Zr02 and carbon additions, the properties are improved differently. Finally, the fine in situ ZrC particles improve the microhardness of composite coating to HV650, which is nearly 2.7 times that of Ni25 coating. Also, the composite coating has an advantage in wear resistance; it offers better wear resistance when more mixture of ZrOand carbon was added in nickel alloys.

关键词： In situ-synthesis Zirconium carbide(ZrC) Composite coating Laser cladding Nickel-based alloy

Influence of dc bias on amorphous carbon deposited by pulse laser ablation

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Rare Metals 2002年第4期21卷 294-298页

作者： yang Yimin, guo jian, CAI Mengqiu, and yang guoweiDepartment of Physics, Xiangtan University, Xiangtan 411105, China Department of Physics Xiangtan University Xiangtan 411105

Amorphous carbon films were deposited on single-crystalline silicon and K9glass by pulse laser ablation using different negative substrate bias. Scanning electron microscope(SEM) was used to observe morphology of the surface. Thickness and refractive index of the filmdeposited on K9 glass were measured by ellipsometry. Micro-hardness of films was measured relativelyto single crystal silicon. All films deposited on silicon were analyzed by Raman spectra. Allspectra were deconvoluted to three peaks. Line-width ratios varied similarly with bias voltage whenthe laser energy was kept invariant.

关键词： negative substrate bias amorphous carbon laser ablation

Node dynamic relaxation method： principle and application

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Frontiers of Materials Science 2011年第2期5卷 179-195页

作者： Hong-Yuan FANG Tao WANG Jun-Feng HU jian-guo yang State Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China

Two main methods, inactive eiement method and quiet element method, to simulate the process of multilayer ：and multipass welding：were reviewed, and the shortcomings of both methods were diScussed as well Based on these analyses, a method called node dynamic relaxation method was put into forward to simulate the multilayer and multipass welding process, and the principle and application of this method were discussed in detail. The simulating results show that using the node dynamic relaxation method can decrease mesh distortion, improve calculation efficiency, and obtain good simulation results. This method can also be used in the field of simulation addition or removing materials in finite element analysis.

关键词： inactive element methodl quiet element methodl node dynamic relaxation method multilayer and multipass Welding finite element analysis (FEA)

Direct C–H amination for indole synthesis from N-Ts-2-Styrylaniline derivatives catalyzed by copper salt

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Chinese Chemical Letters 2015年第8期26卷 969-972页

作者： Di Chen Han-Jie Mo Ding-Ben Chen jian-guo yang School of Pharmaceutical and Chemical Engineering Taizhou University

A direct C–H amination reaction of N-Ts-2-Styrylaniline derivatives to realize the synthesis of indole derivatives was developed in the presence of copper salt. A variety of N-Ts-2-Styrylaniline derivatives were transformed into the corresponding indole products in good to excellent yield under mild conditions with the oxidation of potassium persulfate.

关键词： indole Direct C amination catalyzed equiv potassium intramolecular moiety aromatic bonds

Characterization of a native whitefly vitellogenin gene cDNA and its expression pattern compared with two invasive whitefly cryptic species

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Journal of Integrative Agriculture 2016年第8期15卷 1808-1815页

作者： guo jian-yang DU Yu-ping WAN Fang-hao YE Gong-yin Key Laboratory of Agricultural Entomology Ministry of Agriculture/Institute of Insect Sciences Zhejiang University State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences

supported by grants from the National Basic Research Program of China （2014CB138404）;the China National Science Fund for Innovative Research Groups of Biological Control （31321063）;the National Basic Research Program of China （973 Program, 2009CB119203）;the National Natural Science Foundation for Young Scientists in China （31101674）

关键词： vitellogenin gene Bemisia tabaci MED Asia Ⅱ 1 MEAM1 vitellogenesis displacement

Microscopic damage mechanism of SA508 Gr3 steel in ultra-high temperature creep

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Journal of Iron and Steel Research International 2018年第4期25卷 453-459页

作者： Zhi-gang Xie Yan-ming He jian-guo yang Xiang-qing Li Chuan-yang Lu Zeng-liang Gao Institute of Process Equipment and Control Engineering Zhejiang University of Technology Hangzhou 310014 Zhejiang China Mechanical and Electrical Department Shantou Polytechnic College Shantou 515078 Guangdong China

The lower head of reactor pressure vessel （RPV） will endure a great temperature gradient above the phase transition temperature, and the creep and fracture will be the primary failure mode for the RPV material in such a situation. The interrupted creep tests were performed on a typical RPV material, SA508 Gr3 steel, at 800 ℃. The microstructure of different creep stages was examined by scanning electron microscopy and transmission electron microscopy. The results showed that the microscopic damage is mainly induced by creep cavities and coarse second-phase particles. Furthermore, the volume fractions of creep cavities and coarse second-phase particles show a linear relationship with the extended creep time. The second-phase particles are determined to be MoC in the second creep stage and Mo2C in the third creep stage, according to the results of selected-area electron diffraction pattern. Combined with energy-dispersive spectrum analysis, the segregation of precipitates caused by the migration of atoms is finally unveiled, which leads to the coarsening of the particles.

关键词： Reactor pressure vessel SA508 Gr3 steel In-vessel retention. Second-phase particle Damage mechanism Ultra-high temperature creep