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Chinese Journal of Structural Chemistry 2006年第9期25卷 1148-1153页

作者： xiao guang-Can Center of Analysis and Measurement Fuzhou University Fuzhou Fujian 350002 China

A silver iodide, （ipq）4Ag418 1, has been synthesized in the presence of ipq （ipq = N-（isopentyl）-quinolinium） acting as a structure-directing reagent （SDA）. Compound 1 crystallizes in the triclinic system, space group PT, with a = 9.850（2）, b = 11.564（2）, c = 16.111（3） ,A ,α = 104.64（3）, β = 105.73（3）, γ = 94.37（3）o, V= 1688.3（7） A^3, Z = 2, D,= 2.205 g/cm^3, F（000） = 1042, C28H33Ag2l4N2, Mr= 1120.90, μ（MoKa） = 4.836 mm^-1, the final R = 0.0363 and wR = 0.0761 for 5465 observed reflections with 1 〉 2σ（I）. 1 consists of uncoordinated structure-directing molecule and inorganic moiety tuned by organic SDA. Tetrameric Ag4I8^4- anion in 1 is composed of edgesharing AgI4 tetrahedra and AgI3 planar triangles. Electrostatic interaction between organic counter cations and inorgan!c moieties is present and contributes to the crystal packing. 1 was further characterized with IR, UV-Vis, elemental analysis and cyclic voltammetry. Based on the crystal structure data, quantum chemical calculation with DFr method was used to reveal the electronic structure and optical property of 1.

关键词： coordination polymers template synthesis iodide quaternary ammonium

3D analysis for pit evolution and pit-to-crack transition during corrosion fatigue

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第4期14卷 292-299页

作者： xiao-guang HUANG Jin-quan XU Department of Engineering Mechanics China University of Petroleum Department of Engineering Mechanics Shanghai Jiao Tong University

This paper presents a deterministic model to predict the pit evolving morphology and crack initiation life of corrosion *** on the semi-ellipsoidal pit assumption,the thermodynamic potential including elastic energy,surface energy and electrochemical energy of the cyclically stressed solid with an evolving pit is established,from which specific parameters that control the pit evolution are introduced and their influence on the pit evolution are *** critical pit size for crack nucleation is obtained from stress intensity factor criterion and the crack nucleation life is evaluated by Faraday's ***,this paper presents a numerical example to verify the proposed model and investigate the influence of cyclic load on the corrosion fatigue crack nucleation *** corrosion pit appears approximately as a hemisphere in its early formation,and it gradually transits from semicircle to *** strain energy accelerates the morphology evolution of the pit,while the surface energy decelerates *** higher the stress amplitude is,the smaller the critical pit size is and the shorter the crack initiation life is.

关键词： Pit Evolving morphology Thermodynamic potential Critical pit size Crack nucleation

The microstructure of a single crystal superalloy after different aging heat treatments

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Rare Metals 2018年第3期37卷 210-216页

作者： xiao-Dai Yue Jia-Rong Li xiao-guang Wang Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials

To study the influence of aging heat treatments on the microstructure of single crystal superalloys with high content of refractory elements and optimal the aging heat treatment regimes, a single crystal superalloy containing 22 wt% refractory elements was *** show that for the experimental alloy, even the homogenization-solution heat treatment for 25 h cannot homogenize the alloying elements completely. During primary aging heat treatment, γ＇ phase grows larger and turns to regular cubes. Higher aging temperature induces larger γ＇ cubes. For specimens with primary aging heat treated at 1120 ℃,γ＇ morphology does not change apparently during secondary aging heat treatment. For specimens with primary aging heat treatment at 1150 ℃,γ＇phase in interdendrite grows obviously comparing with that in dendrites. By analyzing the precipitating kinetics of γ＇phase, it is found that owning to the dendrite segregation and different aging heat treatment temperatures, γ＇ phase at different regions grows under the control of different factors at different aging heat treatment stages. The two controlling factors that are driving forces of phase transformation and element diffusion rate induce obviously different growth rates of γ＇ phase. As a result, the γ＇-precipitating behaviors are variable based on different solute concentrations and aging temperatures. For advanced single crystal superalloys that are supposed to be used at relatively high temperatures, the final γ＇ size after aging heat treatment is suggested to be close to the crossing point of diffusion controlling curve and driving force controlling curve corresponding to the serving temperature. And then,high-temperature properties can be improved.

关键词： Single crystal superalloy Aging heat treatment γ' precipitation Kinetics

Effects of Staggered Magnetic Field on Entanglement in the Anisotropic XY Model

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Communications in Theoretical Physics 2006年第1期45卷 61-66页

作者： SUN Zhe WANG xiao-guang Zhejiang Institute of Modern Physics Department of Physics Zhejiang University Hangzhou 310027 China

We investigate effects of staggered magnetic field on thermal entanglement in the anisotropic XY model. The analytic results of entanglement for the two-site cases are obtained. For the general case of even sites, we show that when the anisotropic parameter is zero, the entanglement in the XY model with a staggered magnetic field is the same as that with a uniform magnetic field.

关键词： thermal entanglement staggered magnetic field anisotropic XY model

Porosity model and pore evolution of transitional shales:an example from the Southern North China Basin

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Petroleum Science 2020年第6期17卷 1512-1526页

作者： xiao-guang Yang Shao-Bin Guo School of Energy Resources China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism Ministry of EducationBeijing 100083China

The evolution of shale reservoirs is mainly related to two functions:mechanical compaction controlled by ground stress and chemical compaction controlled by thermal *** simulation experiments were conducted to simulate the chemical compaction of marine-continental transitional shale,and X-ray diffraction(XRD),CO2 adsorption,N2 adsorption and high-pressure mercury injection(MIP)were then used to characterize shale diagenesis and ***,simulations of mechanical compaction adhering to mathematical models were performed,and a shale compaction model was proposed considering clay content and kaolinite *** advantage of this model is that the change in shale compressibility,which is caused by the transformation of clay minerals during thermal evolution,may be *** combination of the thermal simulation and compaction model may depict the interactions between chemical and mechanical *** interactions may then express the pore evolution of shale in actual conditions of ***,the obtained results demonstrated that shales having low kaolinite possess higher porosity at the same burial depth and clay mineral content,proving that other clay minerals such as illite-smectite mixed layers(I/S)and illite are conducive to the development of *** possessing a high clay mineral content have a higher porosity in shallow layers(3500 m).Both the amount and location of the increase in porosity differ at different geothermal *** geothermal gradients favor the preservation of high porosity in shale at an appropriate *** pore evolution of the marine-continental transitional shale is divided into five *** 2 possesses an Ro of 1.0%-1.6%and has high porosity along with a high specific surface *** 3 has an Ro of 1.6%-2.0%and contains a higher porosity with a low specific surface ***,Stage 4 has an Ro of 2.0%-2.9%with a low porosity and h

关键词： Thermal simulation Porosity model Pore evolution Transitional shale Southern North China Basin Shanxi formation

Controlled synthesis and optical properties of Ce^(3+)/Tb^(3+) co-doped BaGdF_5 nanocrystals

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Rare Metals 2015年第9期34卷 673-678页

作者： Chun-Yan Cao An Xie xiao-guang Yu College of Mathematics and Physics Jinggangshan University School of Materials Science and Engineering Xiamen University of Technology

Based on a hydrothermal method, the Ce3+/Tb3+ co-doped Ba Gd F5 nanocrystals were synthesized by controlling the introduction concentration of Ba2+ and Gd3+. The samples were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM) images, photoluminescence(PL) excitation, and emission spectra, as well as the photoluminescence dynamic decay curves. With the increase of the Ba2+ concentration in the synthesis procedure, the positions of diffraction peaks of XRD patterns move toward lower degree, and the case of the samples synthesized with the increase of the Gd3+ concentration is contrary, which consists well with each other. The FE-SEM images suggest that the BaGdF5 nanocrystals are in spherical morphology,and the average diameters decrease with the increase of Ba2+ or Gd3+ concentration. For the 4f–5d transition of Ce3+ is sensitive to the environment of local lattice, the PL excitation and emission spectra of the samples are different. The 4f–4f transition of Tb3+ also presents different optical properties in different host lattices. The variations of the optical properties of Ce3+ and Tb3+ as well as the lifetime of the 5D4+7F5 emission of Tb3+ are also consistent well with each other in the two series of samples.

关键词： Hydrothermal synthesis Optical properties Nanocrys

Low-cycle fatigue lifetime estimation of Ti–6Al–4V welded joints by a continuum damage mechanics model

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Rare Metals 2016年第4期35卷 299-302页

作者： Hong-Yu Qi xiao-Lei Zheng xiao-guang Yang School of Energy and Power Engineering Beihang University Beijing 100191 China

The low-cycle fatigue （LCF） behavior of directionally solidified nickel-based superalloy Ti-6A1-4V was studied under bare and electron beam welding condi- tions at room temperature. Results show that：（1） under the same test conditions, all the joints exhibit lower LCF lifetime than Ti-6A1-4V; （2） the failure of welded structures is mainly ascribed to the welding defect. A novel lifetime prediction methodology based on continuum damage mechanics is proposed to predict the lifetime of Ti-6A1-4V and its welded joints.

关键词： Electron beam welding Low-cycle fatigue Life estimation Continuum damage mechanics

Suppression of Rayleigh-Taylor instability by gyroviscosity and sheared axial flow in imploding plasma pinches

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核聚变与等离子体物理 2007年第2期27卷 87-94页

作者： HUANG Lin JIAN guang-de QIU xiao-ming Southwestern In stitute of Physics Chengdu 610041

The synergistic stabilizing effect of gyroviscosity and sheared axial flow on the Rayleigh-Taylor instability in Z-pinch implosions is studied by means of the incompressible viscid magneto-hydrodynamic *** gyroviscosity(or finite Larmor radius) effects are introduced in the momentum equation through an anisotropic ion stress *** relation with the effect of a density discontinuity is *** results indicate that the short-wavelength modes of the Rayleigh-Taylor instability are easily stabilized by the gyroviscosity *** long wavelength modes are stabilized by the sufficient sheared axial ***,the synergistic effects of the finite Larmor radius and sheared axial flow can heavily mitigate the Rayleigh-Taylor *** synergistic effect can compress the Rayleigh-Taylor instability to a narrow wave number *** with a sufficient gyroviscosity and large enough flow velocity,the synergistic effect can completely suppressed the Rayleigh-Taylor instability in whole wave number region.

关键词：雷利-泰勒不稳定性回转粘性内向爆炸等离子体箍缩增敏作用有限拉莫尔旋进半径增长比率

Motor Imagery EEG Fuzzy Fusion of Multiple Classification

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Journal of Electronic Science and Technology 2017年第1期15卷 58-63页

作者： Lu-Qiang Xu guang-Can xiao School of Computer South West University of Science and TechnologyMianyang 621010China

Due to the volume conduction,electroencephalogram（EEG） gives a rather blurred image of brain activities. It is a challenge for generating satisfactory performance with EEG. This paper studies the multiple areas fusion of EEG classifiers to improve the motor imagery EEG classification performance. Two feature extraction methods are employed to extract the feature from three different areas of EEG. One is power spectral density（PSD）, and the other is common spatial patterns（CSP）. Classifiers are designed based on the well-known linear discrimination analysis（LDA）. The fusion of the individual classifiers is realized by means of the Choquet fuzzy integral. It is demonstrated that the proposed method comes with better performance compared with the individual classifier.

关键词： classifier discrimination satisfactory imagery conduction generating challenge processed projection spatially

Dynamics,topology and bifurcations of McMullen maps

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Applied Mathematics(A Journal of Chinese Universities) 2013年第4期28卷 494-504页

作者： WANG xiao-guang YIN Yong-cheng Department of Mathematics Zhejiang University

We give a survey of many diff erent topological structure arise in the dynamical and parameter planes of McMullen maps.

关键词： Fatou set and Julia set McMullen map hyperbolic component Jordan curve