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Theoretical Studies on the Si(001)-SiO_2 Interface Structure

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Chinese Journal of Structural Chemistry 2006年第6期25卷 647-652页

作者： ZHOU Ming-Xiu YANG Chun DENG Xiao-Yan YU Wei-Fei LI jin-shan Key Laboratory of Computer Software Sichuan Normal University Chengdu Sichuan 610068 China China Academy of Engineering Physics Mianyang Sichuan 621000 China

Novel models （2× 1） of Si（001）-SiO2 interface structure have been established. The method of the first-principle General Gradient Approximation （GGA） is employed to structurally optimize the established theoretical models under the K-point space of periodic boundary condition. The structures after optimization have been analyzed, and the results show that the interfaces present in disordered state and both Si-O-Si and Si=O structures exist. Meanwhile, the bonding of surface structure is analyzed via the graphics of electron localization function（ELF）.

关键词： Si/SiO2 DFT interface structure

Numerical Simulation of Rock Burst in Circular Tunnels Under Unloading Conditions

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Journal of China University of Mining and Technology 2007年第4期17卷 552-556页

作者： SUN jin-shan ZHU Qi-hu LU Wen-bo State Key Laboratory of Water Resource and Hydropower Engineering Science Wuhan University Wuhan Hubei 430072 China

Rock burst in a circular tunnel under high in-situ stress conditions was investigated with a numerical method coupled the rock failure process theory (RFPA) and discontinuous deformation theory (DDA). Some numerical tests were carraied out to investigate the failuer patterns of circular tunnel under unloading conditions. Compared the results under loading conditions,the shapes of failure zones are more regular under the unloading conditions. The failure pat-terns in the same type of rock mass are clearly different because of non-homogeneity of the rock material. The extension of cracks shows some predictability with an increasing of in-situ stress. When the homogeneity index of rocks (m) is ei-ther relatively high or low and lateral pressure coefficients (λ) is high,the number of regular shear slide cracks decreases and the probability of a rock burst also becomes lower. Our numerical simulation results show that the stability of sur-face rock and the natural bedding stratification of rock material greatly affect rock bursts. Installing bolts with due dili-gence and suitably can effectively prevent rock bursts. However,it is not effective to control rock bursts by releasing the strain energy with normal pre-boreholes.

关键词： circular tunnel unloading rock burst numerical simulation RFPA DDA

Static recrystallization behaviors and mechanisms of 7Mo super-austenitic stainless steel with undissolved sigma precipitates during double-stage hot deformation

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Journal of Iron and Steel Research International 2024年第2期31卷 475-487页

作者： Shi-guang Xu jin-shan He Run-ze Zhang Fu-cheng Zhang Xi-tao Wang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004HebeiChina shandong Provincial Key Laboratory for High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Science)Jinan250353ShandongChina

Static recrystallization(SRX)behaviors and corresponding recrystallization mechanisms of 7Mo super-austenitic stainless steel were studied under different deformation *** order of influence of deformation parameters on static recrystallization behaviors,from high to low,is followed by temperature,first-stage strain and strain ***,the effect of holding time on static recrystallization behaviors is significantly controlled by *** addition,with the increase in temperature from 1000 to 1200°C,the static recrystallization mechanism evolves from discontinuous static recrystallization and continuous static recrystallization(cSRX)to metadynamic recrystallization and cSRX,and finally to *** cSRX exists at all *** is because high stacking fault energy(56 mJ m−2)promotes the movement of dislocations,making the deformation mechanism of this steel is dominated by planar slip of *** undissolved sigma precipitates promote static recrystallization through particle-stimulated ***,small strain-induced precipitates at grain boundaries hinder the nucleation of conventional SRX and the growth of recrystallized grains,while the hindering effect decreases with the increase in temperature.

关键词： 7Mo super-austenitic stainless steel Double-stage hot deformation Conventional static recrystallization Metadynamic recrystallization Strain-induced precipitation

Preparation and characterization of high-strength calcium silicate boards from coal-fired industrial solid wastes

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International Journal of Minerals,Metallurgy and Materials 2015年第8期22卷 892-900页

作者： Zhao Cao Yong-dan Cao jin-shan Zhang Chun-bao Sun Xian-long Li Institute of Mining Engineering Inner Mongolia University of Science and Technology Inner Mongolia Engineering Center of Coal Safe Mining & Comprehensive Utilization

To realize the comprehensive utilization of coal-fired industrial solid wastes, a novel high-strength board was prepared from calcium silicate slag, fly ash, and flue gas desulfurization(FGD) gypsum. The changes in mineral phases, chemical structure, and morphology during hydration were investigated by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), and scanning electron microscopy(SEM). A traditional board made from quartz and lime was prepared as a reference. The novel board not only consumes a lot of solid wastes, but also meets the strength requirement of the class-five calcium silicate board according to the Chinese Standard JC/T 564.2—2008. Microanalysis showed that hydrated calcium silicate gel(C-S-H(I)), ettringite, tobermorite, and xonotlite were successively generated in the novel board by synergistic hydration of the mixed solid wastes. The board strength was improved by the formation of tobermorite and xonotlite but decreased by unhydrated quartz. It was demonstrated that quartz was not completely hydrated in the traditional board. As a result, the flexural strength of the traditional board was much lower than that of the novel board.

关键词： solid waste recycling board manufacture calcium si

Improving Existing Drainage and Gas Recovery Technologies: An Experimental Study on the Wellbore Flow in a Horizontal Well

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Fluid Dynamics & Materials Processing 2020年第6期16卷 162-175页

作者： shan jin Xiaohong Bai Wei Luo Li Li Ruiquan Liao School of Petroleum Engineering Yangtze UniversityWuhan430100China Laboratory of Multiphase Pipe Flow of Gas Lift Innovation Center CNPC(Yangtze University)WuhanChina The Branch of Key Laboratory of CNPC for Oil and Gas Production Yangtze UniversityJingzhouChina Oil&Gas Technology Research Institute Changqing Oilfield Branch CompanyPetroChinaXi’anChina

With the increasing number of horizontal wells with low pressure,low yield,and water production,the phenomenon of water and liquid accumulation in gas wells is becoming progressively more *** order to fix these issues,it is necessary to improve existing drainage and gas recovery technologies,increase the fluid carrying capacity of these wells,and ensure that the bottom-hole airflow has enough energy to transport the liquid to the *** the many techniques of drainage and gas recovery,the gas lift has recently become a popular *** the present study,through the simulation of the entire horizontal well,the flow regularity of the whole wellbore during the lift of low-pressure gas has been *** pressure distribution,liquid holdup rate,flow pattern,and energy loss(including gravity loss and friction loss)have been determined using the Beggs-brill *** has been found that the total pressure drop of the wellbore decreases first and increases gradually after reaching a minimum value when gas extraction is carried out via gas *** on the analysis of the influence of the injection volume on wellbore pressure drop and the influence of flow pattern on the lifting efficiency,the optimal gas-lift injection parameters have been determined by taking the minimum pressure loss of wellbore as the judgment criterion.

关键词： Horizontal well gas-liquid two-phase flow gas lift flow pattern pressure pressure drop

Hot corrosion behavior and mechanical properties degradation of a Ni–Cr–W-based superalloy

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Rare Metals 2017年第1期36卷 23-31页

作者： Ruj-Feng Dong Tie-Bang Zhang Rui Hu Hong-Chao Kou jin-shan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072 China

The effect of molten salts on the mechanical properties of a Ni–20Cr–18W(wt%)-based superalloy was investigated in this work. The hot corrosion characteristics and the microstructural evolution during the hot corrosion process were analyzed. The corrosion scale forms on the surface of the substrate, and its thickness increases gradually during the process. The element of S invades the substrate. The corrosion products mainly include Ni O,Ni_3S_2 and Cr_2O_3. The hot corrosion in molten salt makes the specimens rough and flawed. The serration grain boundaries are observed in the hot corroded *** tensile strength and elongation of the original alloy are^1023 MPa and ~15 %, respectively. After corroded for5 h, the tensile strength and elongation of the specimen decrease to ~771 MPa and ~7 % and diminish to^814 MPa and ~9 % for the specimen corroded for 10 *** hot corrosion process deteriorates the mechanical properties of the alloys. And the tensile strength and elongation of the specimen corroded for 20 h sharply decrease to ~539 MPa and ~3 %, respectively. The nonmonotonic variation of the mechanical properties of the specimen occurs for the specimens corroded for 10 h,which is related to the competition between the depredation of the molten salts and the strengthening process by carbides and the serrated grain boundaries.

关键词： Ni-based superalloys Hot corrosion behavior Microstructural evolution Grain boundary Mechanical properties

Mechanical properties and microstructure of in situ formed Ti_(2)AlN/TiAl(WMS)composites

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Rare Metals 2021年第1期40卷 190-194页

作者： Wan-Liang Liang Rui Hu Yi-Wen Liu Tie-Bang Zhang jin-shan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

The Ti_(2)AlN-reinforced TiAl(WMS)composites with different contents of Ti_(2)AlN were prepared by an in situ method of reactive arc-melting *** to the results of X-ray diffraction(XRD)analysis,the Ti_(2)AlNreinforced WMS composites consist ofγ-TiAl,α_(2)-Ti_(3)Al,and Ti_(2)AlN *** analysis results indicate that Ti_(2)AlN reinforcements with rod-like in shape form in the WMS matrix with aα_(2)/γlamellar structure containing some bulk y *** volume fraction of Ti_(2)AlN increasing,the grain size of the composites decreases significantly and the elasticity modulus(E)*** compressive strength and compressive fracture strain of the composite with 3 vol%Ti_(2)AlN have a maximum value of 1,654 MPa and 22.5%,respectively,which are approximately improved by 45.84%and 29.31%,respectively,compared with that of the unreinforced WMS alloy.

关键词： Ti_(2)AlN/TiAl(WMS)composites Reactive arc-melting Microstructure Compressive properties

Development of a Novel Kilowatt Microwave Plasma Torch Source for Atomic Emission Spectrometry

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Chemical Research in Chinese Universities 2017年第5期33卷 709-713页

作者： ZHU Dan jin Wei YU Bingwen YING Yangwei YU Haixiang shan jin YAN Yuwei XU Chen WANG Baolai jin Qinhan Research Center for AnalyticaI Instrumentation Institute of Cyber-systems and ControlCollege of Control and Engineering Zhejiang University Hangzhou 310058 P. R. China Zhejiang Tracetech Technology Co. Ltd. Hangzhou 310053 P. R. China Hangzhou Steam Turbine Co. Ltd. Hangzhou 310022 P R. China

Traditional low power-microwave plasma torch（MPT） excitation source of atomic emission spectrometry was shown to be good for the introduction of dry aerosols, but poor for wet sample aerosols. In this work, some significant modifications have been made to traditional MPT. A new MPT excitation source working at kilowatt microwave power has been developed. The kilowatt MPT source can sustain stable plasmas with double or even more filaments, presenting a ＂bell＂ form, where the region around the converging point is the optimum region for analysis. The tolerance to aqueous aerosol of the torch is enhanced significantly compared to the traditional one. Therefore, the desolvation system that the low power MPT source has to be relied on can be gotten rid of. A set of favorable detection results have been obtained with direct wet sample aerosol introduction. The kilowatt MPT source is expected to become a practical excitation source for atomic emission spectrometry that will be widely used.

关键词： Kilowatt microwave plasma torch Coupling structure Direct sample aerosol introduction Atomic emis- sion spectrometry

Effect of nano-selenium loaded with lycium barbarum polysaccharide on the proliferation of lens epithelial cells after UVB damage in vitro

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International Journal of Ophthalmology(English edition) 2022年第1期15卷 9-14页

作者： jing-Xiang Zhong shan-shan jin Kang-Sheng Wu Guo-Cheng Yu Lei-Lei Tu Lian Liu Department of Ophthalmology the First Affiliated Hospital of Jinan UniversityGuangzhou 510630Guangdong ProvinceChina

AIM:To investigate the effect of nano-selenium loaded with different concentrations of lycium barbarum polysaccharide(LBP-Se NPs)on the proliferation of human lens epithelial cells(HLECs)from UV ***:LBP-Se NPs were prepared and their particle size was ***(SRA01/04)were irradiated with UVB for different time(0,10,20,30,40,50,60 min)to construct a damaged model,the survival rate of cells was determined by methylthiazol tetrazolium(MTT)*** 4’,6-Diamidine-2’-phenylindole dihydrochloride(DAPI)staining was used to observe the status of cell nucleus and drug entering cytoplasm through cell membrane in SRA01/04 cells after adding LBP-SENPS loaded with coumarin fluorescence agent 24 h under fluorescence ***01/04 normal and UVB-damaged cells were treated with different amounts of LBP-Se NPs at different concentrations,cells proliferation were ***:The particle size of LBP-Se NPs was stable in the range of 150-200 *** survival rate changes with time after UVB irradiation were statistically *** 10 min of UVB exposure as the time was chosen to construct the cell damage *** DAPI staining,LBPSe NPs were observed to enter the cytoplasm through the cell membrane under fluorescence inverted *** of SRA01/04 at different concentrations of LBPSe NPs were *** survival rate was statistically different compared with the control *** higher the loading concentration of LBP in nano-Se drugs was,the higher the cell proliferation rate was(P<0.05).The lower the concentration of LBP-Se NPs,the higher the cell proliferation rate,showing a negative growth trend(P<0.05).The group with the highest average cell proliferation rate was 0.5μmol/L 2.0 mg/m L LBP-Se NPs(128.80%).When the 2.0 mg/m L LBP-Se NPs group was selected for cell photography,the cell density was higher at 0.5μmol/*** the increase of concentration,SRA01/04 cells appeared more cytoplasm dehydration,cell shrinkage and ap

关键词： lycium barbarum polysaccharide nano-selenium human lens epithelial cells ultraviolet irradiation