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Morphology and Propagation of Hydraulic Fractures for CBM Wells

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Acta Geologica Sinica(English Edition) 2017年第5期91卷 1936-1937页

作者： WU Caifang zhang xiaoyang Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of Education China University of Mining and Technology Xuzhou 221008 Jiangsu China School of Resources and Geosciences China University of Mining and Technology Xuzhou 221116 Jiangsu China

Objective As the most widely used and effective technique in reservoir reconstruction of unconventional natural gas,hydraulic fracturing has been achieved good effect in CBM *** is important to note that coal seam is ... 详细信息

关键词： In Morphology and Propagation of Hydraulic Fractures for CBM Wells

A numerical investigation of gas flow behavior in two-layered coal seams considering interlayer interference and heterogeneity

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International Journal of Mining Science and Technology 2021年第4期31卷 699-716页

作者： Ziwei Wang Yong Qin Teng Li xiaoyang zhang Key Laboratory of Coalbed Methane Resources&Reservoir Formation Process Ministry of EducationChina University of Mining and TechnologyXuzhou 221116China School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221116China College of Petroleum Engineering Xi’an Shiyou UniversityXi’an 710065China College of Earth Sciences and Engineering Shandong University of Science and TechnologyQingdao 266590China

Multiple-seam gas coproduction is a technology with potential to achieve economic *** experiments could replicate gas flow dynamics in two *** this study,numerical simulation was conducted based on physical *** calibration,the simulated results agreed with the experimental *** findings were ***,the pressure distribution intrinsically depends on the depressurization effectiveness in each coal *** gas pressure difference and interval distance influence the pressure distribution by inhibiting depressurization in the top seams and bottom seams,***,the production contribution shows a logarithmic relationship with the permeability *** range of the production contribution difference grows from 11.24%to 99.99%when the permeability ratio increases 50 *** comparison,reservoir pressure has a limited influence,with a maximum of 13.64%.Third,the interlayer interference of the top seams and bottom seams can be intensified by the reservoir pressure difference and the interval distance,*** proposed model has been calibrated and verified and can be directly applied to engineering,serving as a reference for reservoir combination *** summary,coal seams with a permeability ratio within 10,reservoir pressure difference within 1.50 MPa,and interval distances within 50 m are recommended to coproduce together.

关键词： Sublayer interlayer interference index Permeability ratio Reservoir pressure difference Interval distance Production contribution

Mapping Crop Phenology in Near Real-Time Using Satellite Remote Sensing: Challenges and Opportunities

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Journal of Remote Sensing 2021年第1期2021卷 96-109页

作者： Feng Gao xiaoyang zhang USDA Agricultural Research Service Hydrology and Remote Sensing Laboratory10300 Baltimore AvenueBeltsvilleMD 20705USA Geospatial Sciences Center of Excellence Department of Geography and Geospatial SciencesSouth Dakota State UniversityBrookingsSD 57007USA

Crop phenology is critical for agricultural management,crop yield estimation,and agroecosystem ***,crop growth stages are observed from the ground,which is time-consuming and lacks spatial *** sensing Vegetation Index(VI)time series has been used to map land surface phenology(LSP)and relate to crop growth stages mostly after the growing *** recent years,high temporal and spatial resolution remote sensing data have allowed near-real-time mapping of crop phenology within the growing *** paper summarizes two classes of near-real-time mapping methods,i.e.,curve-based and trend-based *** curve-based approaches combine the time series VIs and crop growth stages from historical years with the current observations to estimate crop growth *** curve-based approaches are capable of a shortterm *** trend-based approaches detect upward or downward trends from time series and confirm the trends using the increasing or decreasing momentum and VI *** trend-based approaches only use current *** curve-based and trend-based approaches are promising in mapping crop growth stages ***,mapping crop phenology near real-time is challenging since remote sensing observations are not always sensitive to crop growth *** accuracy of crop phenology detection depends on the frequency and availability of cloud-free observations within the growing *** satellite datasets such as the harmonized Landsat and Sentinel-2(HLS)are promising for mapping crop phenology within the season over large *** applications in the near future are feasible.

关键词： Crop fir season

Impact of H_(2)S on Hg^(0)capture performance over nitrogen-doped carbon microsphere sorbent:experimental and theoretical insights

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Frontiers of Chemical Science and Engineering 2024年第3期18卷 89-100页

作者： Guopei zhang xiaoyang zhang Xiangwen Xing Xiangru Kong Lin Cui Dong Yong National Engineering Laboratory for Reducing Emissions from Coal Combustion Shandong UniversityJinan250061China Bingtuan Energy Development Institute Shihezi UniversityShihezi832000China

A nitrogen-doped carbon microsphere sorbent with a hierarchical porous structure was synthesized via aggregation-hydrothermal *** Hg^(0)adsorption performance of the nitrogen-doped carbon microsphere sorbent was tested and compared with that of the coconut shell activated carbon prepared in the *** effect of H_(2)S on Hg^(0)adsorption was also *** nitrogen-doped carbon microsphere sorbent exhibited superior mercury removal performance compared with that of coconut shell activated *** the absence of H_(2)S at a low temperature(≤100℃),the Hg^(0)removal efficiency of the nitrogen-doped carbon microsphere sorbent exceeded 90%.This value is significantly higher than that of coconut shell activated carbon,which is approximately 45%.H_(2)S significantly enhanced the Hg^(0)removal performance of the nitrogen-doped carbon microsphere sorbent at higher temperatures(100–180℃).The hierarchical porous structure facilitated the diffusion and adsorption of H_(2)S and Hg^(0),while the nitrogen-containing active sites significantly improved the adsorption and dissociation capabilities of H_(2)S,contributing to the generation of more active sulfur species on the surface of the nitrogen-doped carbon microsphere *** formation of active sulfur species and HgS on the sorbent surface was further confirmed using X-ray photoelectron spectroscopy and Hg^(0)temperature-programmed desorption *** functional theory was employed to elucidate the adsorption and transformation of Hg^(0)on the sorbent surface.H_(2)S adsorbed and dissociated on the sorbent surface,generating active sulfur species that reacted with gaseous Hg^(0)to form HgS.

关键词： nitrogen-doped carbon microsphere H_(2)S Hg^(0)removal adsorption mechanism

Irreversible phenotypic perturbation and functional impairment of B cells during HIV-1 infection

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Frontiers of Medicine 2017年第4期11卷 536-547页

作者： Jingjing Yan Shuye zhang Jun Sun Jianqing Xu xiaoyang zhang Shanghai Public Health Clinical Center & Institutes of Biomedical Sciences Fudan University Shanghai 201508 China

Human immunodeficiency virus type 1 （HIV-1） infection can damage humoral immunity. The knowledge of B cell perturbations during chronic HIV-1 infection and their recovery after combined antiretroviral therapy （cART） is not complete yet, and thus attempts to further improve humoral immunity are impeded. In this study, an HIV-1 chronically infected cohort with similar demographics, infection history, genetic background, and HIV-1 genotype was established to probe B cell perturbations. Results showed that the B cells from this cohort were highly activated and prone to cell death, and B cell compartments were altered significantly. Notably, although cART partially reversed the hyperactivation and reduced tissue-like memory B cells, other B cell perturbations, including impaired expression of survival factor Bcl-2, costimulatory molecules, and shrunken resting memory B cells, were irreversible. Further functional characterization revealed that the influenza HA- specific antibody-secreting cells were significantly lower during HIV-1 infection, whereas the recalled antibody response to HIV-l-specific antigens was decreased after cART. Finally, CpG plus R848 treatment increased the survival of B cells and memory B cells in vitro from HIV-l-infected patients. In conclusion, this study identified irreversible B cell immune perturbations in chronic HIV-1 infections regardless of cART and proposed the potential strategy to enhance B cell functions through the improvement of cell survival.

关键词： B cell HIV-1 phenotype functionality antiretroviral therapy

Enhanced Data Transmission Rate of XCTD Profiler Based on OFDM

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Journal of Ocean University of China 2019年第5期18卷 1079-1085页

作者： LI Hongzhi zhang Sai QIN Xiaocong zhang xiaoyang ZHENG Yu National Ocean Technology Center Tianjin 300112China School of Electronics and Information Engineering Tianjin Polytechnic UniversityTianjin 300387China

An expendable conductivity-temperature-depth profiler(XCTD)is one of the most important instruments used to obtain hydrological data,such as temperature and conductivity,and detect ocean depth in a large ***,the XCTD channel provides poor time-varying performance,narrowband,and low signal-to-noise ratio(SNR),which severely restricts the data transmission *** contrast to conventional single-carrier modulation techniques,such as amplitude-shift keying and differential phase-shift keying,this article provides a new method,based on orthogonal frequency division multiplexing(OFDM)to enhance the data transmission rate of deep-sea abandoned *** apply the OFDM to enhance the SNR of the XCTD,which is achieved by reducing the data transmission rate of each ***,the bandwidth utilization may be improved by increasing the number of subcarriers in a given bandwidth,which enhances the data transmission *** on analysis of the XCTD channel model,OFDM with different parameters such as constellation mapping,number of subcarriers,subcarrier spacing,signal period and cyclic prefix are *** verify the effectiveness of the OFDM,this study investigates the influence of different parameters on the data transmission rate at different noise levels,i.e.,-20 dB and-40 d B.

关键词： XCTD OFDM subcarrier bandwidth utilization data transmission rate

Morphology characteristics of α precipitates related to the crystal defects and the strain accommodation of variant selection in a metastableβtitanium alloy

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Journal of Materials Science & Technology 2021年第36期95卷 1-9页

作者： Ruifeng Dong Hongchao Kou Yuhong Zhao xiaoyang zhang Ling Yang Hua Hou School of Materials Science and Engineering North University of ChinaTaiyuan030051China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China

Profound and comprehensive investigations on the morphology characteristics ofαprecipitates are essential for the microstructural control of metastableβtitanium *** the very beginning of aging treatment,intragranularαprecipitates with a dot-like morphology begin to generate nearby the dislocations,then those dot-likeαprecipitates with the same crystallographic orientation tend to connect with each other to develop a lath-like *** the progress of aging treatment,the orientated lath-likeαprecipitates gradually combine with each other to form the V-shaped clusters or the triangular *** dislocations of{110}_(β)βedge type are evidenced within theβgrains,and it is found that variant selection ofαprecipitates induced by the transformation strain and the interplay betweenαvariants and the dislocations are confirmed as the key factors for the formation of the V-shaped or triangular *** results of this work could provide underlying knowledge on the morphology characteristics of intraguranularαprecipitates related to the crystal defects and the strain accommodation ofαvariants in metastableβtitanium alloys.

关键词： Metastableβtitanium alloys αPrecipitates Morphology characteristics Phase transformation Strain accommodation Dislocations

Lateral Pressure of RC Silos with Static and Dynamic Granular Materials

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Journal of Harbin Institute of Technology(New Series) 2015年第4期22卷 92-98页

作者： Kunpeng Guo Changdong Zhou xiaoyang zhang Lingkai Meng School of Civil Engineering Beijing Jiaotong University

This paper aims at analyzing material-induced lateral pressure of RC cylinder silo in both static and dynamic condition using the finite element method( FEM). In the finite element software ABAQUS,concrete material is modeled by concrete damaged plasticity model,and stored materials in silo is modeled by the hypoplastic *** terms of numerical model,shell elements( S4R) and solid elements( C3D8) are applied for model silo wall and stored materials respectively. The interaction between silo wall and stored materials is simulated by Coulomb friction model and penalty contact constrain provided by *** numerical results are verified with the existing experimental data that are designed to ensure the validation of such numerical model using FEM and it obtains good agreements between numerical results and experimental data. Then the material parameters are analyzed in both static and dynamic *** to the analysis,it is clear that critical friction angle,initial void ratio and minimum void ratio have an obvious effect on static lateral pressure while all the material parameters affect dynamic lateral pressure at different levels. In addition,differences of silo wall between elastic and plastic state are analyzed in dynamic condition. The numerical results show that it contributes to increasing dynamic pressure when silo wall enters into the plastic state. Finally,this paper discusses the time-history lateral pressure at different heights along silo wall,and analytical results indicate that larger acceleration values play main roles in producing the maximum lateral pressure at higher part of the silo wall.

关键词： RC cylinder silo static lateral pressure dynamic lateral pressure hypoplastic theory FEM

Ecosystem Health Assessment of Honghu Lake Wetland of China Using Artificial Neural Network Approach

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Chinese Geographical Science 2009年第4期19卷 349-356页

作者： MO Minghao WANG Xuelei WU Houjian CAI Shuming xiaoyang zhang WANG Huiliang School of Resource and Environmental Science Wuhan University Wuhan 430079 China Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China Central South Forest Inventory and Planning Institute of State Forestry Administration Changsha 410014 China ERT at NOAA/NESDIS/STAR Camp Springs Maryland USA

Honghu Lake,located in the southeast of Hubei Province,China,has suffered a severe disturbance during the past few *** restore the ecosystem,the Honghu Lake Wetland Protection and Restoration Demonstration Project(HLWPRDP) has been implemented since 2004.A back propagation(BP) artificial neural network(ANN) approach was applied to evaluatinig the ecosystem health of the Honghu Lake *** the effectiveness of the HLWPRDP was also assessed by comparing the ecosystem health before and after the ***,12 ecosystem health indices were used as evaluation parameters to establish a set of three-layer BP *** output is one layer of ecosystem health *** training and testing the BP ANNs,an optimal model of BP ANNs was selected to assess the ecosystem health of the Honghu Lake *** result indicates that four stages can be identified based on the change of the ecosystem health from 1990 to 2008 and the ecosystem health index ranges from morbidity before the implementation of HLWPRDP(in 2002) to middle health after the implementation of the HLWPRDP(in 2005).It demonstrates that the HLWPRDP is effective and the BP ANN could be used as a tool for the assessment of ecosystem health.

关键词： ecosystem health artificial neural network wetland restoration Honghu Lake