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A numerical investigation of hydraulic fracturing on coal seam permeability based on PFC‑COMSOL coupling method

International Journal of Coal Science & Technology 2022年第1期9卷 183-199页

作者： Kai Wang guodong zhang Yanhai Wang Xiang zhang Kangnan Li Wei Guo Feng Du Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources China University of Mining and Technology(Beijing)Beijing 100083China School of Emergency Management and Safety Engineering China University of Mining and Technology(Beijing)Beijing 100083China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology(Beijing)Beijing 100083China

Hydraulic fracturing and permeability enhancement are effective methods to improve low-permeability coal ***,few studies focused on methods to increase permeability,and there are no suitable prediction methods for engineering *** this work,PFC2D software was used to simulate coal seam hydraulic *** results were used in a coupled mathematical model of the interaction between coal seam deformation and gas *** results show that the displacement and velocity of particles increase in the direction of minimum principal stress,and the cracks propagate in the direction of maximum principal *** gas pressure drop rate and permeability increase rate of the fracture model are higher than that of the non-fracture *** parameters decrease rapidly with an increase in the drainage time and approach *** longer the hydraulic fracturing time,the more complex the fracture network is,and the faster the gas pressure ***,the impact of fracturing on the gas drainage effect declines over *** the fracturing time increases,the difference between the horizontal and vertical permeability ***,this difference decreases as the gas drainage time *** higher the initial void pressure,the faster the gas pressure drops,and the greater the permeability increase ***,the influence of the initial void pressure on the permeability declines over *** research results provide guidance for predicting the anti-reflection effect of hydraulic fracturing in underground coal mines.

关键词： Fracturing simulation Gas drainage Fracturing effect prediction Permeability enhancement

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Single-and multiple-scattering properties of ice crystals in 1.38 μm wavelength and its potential applications in satellite remote sensing

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Chinese Science Bulletin 1999年第7期44卷 650-654页

作者： guodong zhang Lisheng Xu Tamio Takamura Jilie Ding Atmospheric Radiation and Satellite Remote Sensing Laboratory Chengdu Meteorological College Chengdu China LSSR Peking University Beijing China Center for Environmental Remote Sensing Chiba University Chiba Japan

An improved ray-optics theory and Mie theory for single scattering and the adding-doubling method for multiple scattering are used to study the relationship between the radiation in the wavelengths of 1.38, 3.979, 6.5, and 11.03 μm and the microphysics of cirrus clouds. It is shown that the strong 1.38 μm water vapor band in the near-IR region is superior to the other three IR channels used in current operational satellites and has potential possibility of remote sensing of microphysical and optical properties of cirrus clouds.

关键词： ice crystals single scattering multiple scattering remote sensing channel.

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Surface Organic Modification of Fe_3O_4 Magnetic Nanoparticles

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Journal of Wuhan University of Technology(Materials Science) 2008年第4期23卷 436-439页

作者： CUI Sheng SHEN Xiaodong LIN Benlan JIANG guodong zhang Weihua College of Material Science and Technology Nanjing University of Technology Nanjing 210009 China

The surface organic modification of Fe3O4 nanoparticles with silane coupling reagent KH570 was studied. The modified and unmodified nanoparticles were characterized by FT-IR, XPS and TEM. The spectra of FT-IR and XPS revealed that KH570 was coated onto the surface of Fe3O4 nanoparticles to get Fe-O- Si bond and an organic coating layer also was formed. Fe3O4 nanoparticles were spheres partly with mean size of 18,8 nm studied by TEM, which was consistent with the result 17.9 nm calculated by Scherrer＇s equation. KH570 was adsorbed on surface and formed chemistry bond to be steric hindrance repulsion which prevented nanoparticles from reuniting. Then glycol-based Fe3O4 magnetic liquids dispersed stably was gained.

关键词： Fe3O4 nanoparticles KH570 surface organic modification chemical adsorb dispersivity

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CFD-Based Optimization of a Diesel Engine Waste Heat Recycle System

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Fluid Dynamics & Materials Processing 2023年第6期19卷 1479-1493页

作者： Da Li guodong zhang Ke Sun Shuzhan Bai Guoxiang Li School of Energy and Power Engineering Shandong UniversityJinan250061China

A dedicated heat exchanger model is introduced for the optimization of heavy-duty diesel *** model is a prerequisite for the execution of CFD simulations,which are used to improve waste heat recovery in these *** optimization methods coupled with different types of working fluids are compared in terms of exergy efficiency and heat exchanger *** three considered optimization methods all lead to significant improvements in the R245fa and R1233zd systems with a comparatively low evaporation *** optimal R245fa system has the highest efficiency increase(77.49%).The cyclopentane system displays the highest efficiency among the optimized ORC(Organic Rankine Cycle)systems,yet achieved by using a much heavier evaporator HEC(Heat Exchanging Core).In contrast,the 96.84%efficiency increase for the optimized R1233zd is achieved with only 68.96%evaporator weight.

关键词： Tube-fin heat exchanger heat exchanging core organic rankine cycle working fluid

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Computer Simulating Calculation on the Microstructure Evolutions during Hot Strip Rolling of C-Mn Steels

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Journal of Materials Science & Technology 1994年第3期10卷 221-224页

作者： Zhenyu LIU guodong WANG and Qiaing zhang(Northeastern University, Shenyang, 110006, China) Northeastern Univ Shenyang China

The program to predict the microstructure evolutions during hot strip rolling of C-M n steels has been developed in this paper, BV using this program, the microstructure changes with the processing parameters were analysed in detail. showing not only a good agreement of prediction with the measured values, but also entirely possibility to optimize hot strip rolling precess by computer simulation

关键词： Mn Computer Simulating Calculation on the Microstructure Evolutions during Hot Strip Rolling of C-Mn Steels Figure

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Near-infrared emitting metal halide materials:Luminescence design and applications

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InfoMat 2024年第5期6卷 1-46页

作者： Dongjie Liu Peipei Dang guodong zhang Hongzhou Lian Guogang Li Jun Lin State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunthe People's Republic of China University of Science and Technology of China Hefeithe People's Republic of China Faculty of Materials Science and Chemistry China University of GeosciencesWuhanthe People's Republic of China Zhejiang Institute China University of GeosciencesHangzhouthe People's Republic of China

Near-infrared(NIR)luminescent metal halide(LMH)materials have attracted great attention in various optoelectronic applications due to their low-temperature solution-processable synthesis,abundant crystallographic/electronic structures,and unique optoelectronic ***,some challenges still remain in their luminescence design,performance improvement,and application *** review systematically summarizes the development of NIR LMHs through classifying NIR luminescent origins into four major categories:band-edge emission,self-trapped exciton(STE)emission,ion emission,and defect-related *** luminescence mechanisms of different types of NIR LMHs are discussed in detail by analyzing typical *** strategies for design-ing and optimizing luminescence/optoelectronic properties of NIR LMHs are summarized,including bandgap engineering,self-trapping state engineering,chemical composition modification,energy transfer,and other auxiliary strategies such as improvement of synthesis scheme and ***,application prospects based on the optoelectronic devices are revealed,including phosphor-converted light-emitting diodes(LEDs),electroluminescent LEDs,pho-todetectors,solar cells,and x-ray scintillators,as well as demonstrations of some related practical ***,the existing challenges and future perspec-tives on the development of NIR LMH materials are critically *** review aims to provide general understanding and guidance for the design of high-performance NIR LMHs materials.

关键词： luminescence design metal halides near-infrared luminescent materials optoelectronic applications performance improvement

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Effects of Chrome Oxide Concentrate Powder on Properties of Magnesia Composite Materials

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China's Refractories 2012年第2期21卷 7-10页

作者： zhang guodong LUO Xudong LIU Haixiao Department of High Temperature Materials and Magnesium Resource Engineering University of Science and Technology Liaoning Anshan 114051 China Department of Material and Metallurgy University of Science and Technology Liaoning Anshan 114051 China

The magnesia composite materials were prepared using fused magnesia, used magnesia chrome bricks, magnesium aluminate spinel, alumina powder and chrome oxide powder as starting materials. In order to improve the performance of magnesia composite material, the influence of chrome oxide concentrate powder on the properties of magnesia composite material was re-searched. The apparent porosity, bulk density, cold crushing streugth, linear expausion and thermal shock resistance of the specimens were determined. The results show that adding chrome oxide concentrate promotes the formation of the composite phases of three kinds of spi-nel, which is beneficial to the thermal shock *** magnesia chrome spbwl can not be .[brined at high temperatures theoreticalby, but can dissolve in the mag-nesia composite material. Comprehensively, the optimal addition of chrome oxide concentrate is 10. 0 mass% for the magnesia composite materials.

关键词： magnesia composite material chrome ox-ide concentrate magnesia chrome spinel thermalshock resistance

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Lutein-stevioside nanoparticle attenuates H_(2)O_(2)-induced oxidative damage in ARPE cells

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Food Science and Human Wellness 2024年第3期13卷 1628-1635页

作者： Zhuqing Dai Meimei Nie Ye Chen Jiangfeng Song Yayuan Xu Zhongyuan zhang guodong zhang Shumo Yan Xing zhang Dajing Li Institute of Agro-Product Processing Jiangsu Academy of Agricultural SciencesNanjing 210014China Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base Ministry of Science and TechnologyNanjing 210014China Jiangsu Aland Nutrition Co. Ltd.Taizhou 214500China Aland Nutrition Taizhou Co. Ltd.Taizhou 225300China

In order to improve the bioavailability of lutein(LUT),a novel lutein-stevio side nanoparticle(LUT-STE)were prepared previously,but the information about LUT-STE on protecting of eye health was *** study investigated the effect of LUT-STE on antioxidant activity of H_(2)O_(2)-induced human retinal pigment epithelial(ARPE)*** and LUT-STE(final concentration of 5μg/mL)significantly enhanced cell viability from(74.84±5.10)%to(81.92±10.01)%(LUT)and(89.33±4.34)%(LUT-STE),and inhibited the cell apoptosis(P<0.05).After pretreatment with LUT-STE in ARPE cells,the levels of superoxide dismutase(SOD),catalase(CAT)and glutathion peroxidase(GSH-Px)in ARPE cells were significantly increased(P<0.05),the contents of reactive oxygen species(ROS)and malondialdehyde(MDA)were *** addition,the vascular endothelial growth factor(VEGF)levels were inhibited by 13.61%and 17.39%,respectively,pretreatment with LUT and *** blotting results showed that the pretreatment with LUT-STE inhibited the expression of caspase-9 and caspase-3 and up-regulated Bcl-2/Bax pathway to inhibit H_(2)O_(2)-induced *** summary,the novel delivery LUT-STE had more pronounced inhibitory effect on H_(2)O_(2)-induced damage in human ARPE cells.

关键词： Lutein Stevioside Antioxidant Human retinal pigment epithelial cell Mechanism

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Epitaxial growth of ultrathin ZrO_2(111) films on Pt(111)

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Chinese Science Bulletin 2011年第6期56卷 502-507页

作者： GAO Yan zhang Liang PAN YongHe WANG guodong XU Yang zhang WenHua ZHU JunFa National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230029 China

Ordered epitaxial ZrO2 films were grown on Pt(111) and characterized by low energy electron diffraction (LEED), synchrotron radiation photoemission spectroscopy (SRPES) and X-ray photoelectron spectroscopy (XPS). The films were prepared by vapor deposition of zirconium in an O2 atmosphere followed by annealing under ultra high vacuum. At low coverages, the films grew as discontinuous two-dimentional islands with ordered structures. The size and structure of these islands were dependent on the coverage of ZrO2 films. At coverage 6 ML, a continuous ZrO2(111) film was formed with a (1×1) surface LEED pattern coexisting with a (2×2) pattern. These ordered thin ZrO2 films provide good model surfaces of bulk ZrO2 and can be used for further fundamental studies of the surface chemistry of ZrO2 using modern surface science techniques.

关键词：二氧化锆薄膜薄膜外延生长同步辐射光电子能谱超薄有序结构表面图案低能电子衍射化学基础研究

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Numerical Simulation on Interfacial Creep Failure of Dissimilar Metal Welded Joint between HR3C and T91 Heat-Resistant Steel

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Journal of Wuhan University of Technology(Materials Science) 2016年第5期31卷 1068-1074页

作者：张建强 TANG Yi zhang guodong ZHAO Xuan GUO Jialin LUO Chuanhong Key Laboratory of Hubei Province of Water Jet Theory and New Technology Wuhan University Wuhan 430072 China Research Institute of Nuclear Power Operation Wuhan 430074 China

The maximum principal stress, von Mises equivalent stress, equivalent creep strain, stress triaxiality in dissimilar metal welded joints between austenitic（HR3C） and martensitic heat-resistant steel（T91） are simulated by FEM at 873 K and under inner pressure of 42.26 MPa. The results show that the maximum principal stress and von Mises equivalent stress are quite high in the vicinity of weld/T91 interface, creep cavities are easy to form and expand in the weld/T91 interface. There are two peaks of equivalent creep strains in welded joint, and the maximum equivalent creep strain is in the place 27-32 mm away from the weld/T91 interface, and there exists creep constrain region in the vicinity of weld/T91 interface. The high stress triaxiality peak is located exactly at the weld/T91 interface. Accordingly, the weld/T91 interface is the weakest site of welded joint. Therefore, using stress triaxiality to describe creep cavity nucleation and expansion and crack development is reasonable for the dissimilar metal welded joint between austenitic and martensitic steel.

关键词： dissimilar metal welded joint maximum principal stress equivalent stress creep strain stress triaxiality

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