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Application of remote sensing in the description of fluvial system in dryland:A case study of Golmud distributive fluvial system,Qaidam Basin,NW China

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Journal of Palaeogeography 2022年第4期11卷 601-617页

作者： xiang-Hui Zhang Chang-Min Zhang wen-jie Feng Rui Zhu Qing-Hai Xu School of Geosciences Yangtze UniversityWuhan430100Hubei ProvinceChina

Distributive fluvial systems(DFS)are widespread in drylands in the northwestern *** differences in fluvial morphology in drylands is beneficial for studying ancient rock records and the extraterrestrial surface *** remote sensing image,characterized by real-time and possibility of repeated observations,is a vital tool for recording and comparing fluvial systems in *** remote sensing technology is a method of investigating fluvial *** to the limited accuracy of satellite imagery,there are few reports on the detailed description of the fluvial system in drylands of NW *** analyze the pattern of fluvial morphology changes in the Golmud distributive fluvial system(DFS)in the Qaidam Basin,northwestern China,using satellite remote sensing and unmanned aerial vehicles(UAV).Firstly,we use Google Earth real-time image data,historical image data,and radar digital elevation data to extract geomorphological information;then the UAV remote sensing image data were used to interpret fluvial network information;finally,we use the gray-scale differential vector method to describe the fluvial *** zones have been identified in the Golmud DFS:the proximal,the medial,and the distal,by comparing the differences in topographic and geomorphic characteristics,fluvial morphologies,and sedimentary characteristics of the Golmud *** proximal slope is higher than the other two zones,and the geomorphic features are mainly gravel *** proximal fluvial morphologies are mainly large braided rivers,and sediments are more gravelly and less *** medial slope is relatively small,and the geomorphic features are mostly oasis *** medial fluvial morphologies are mainly meandering rivers associating with braided rivers,and sediments are more sandy and less *** distal slope is the lowest,and the geomorphic features are mostly oasis plains,lakes,and marsh *** distal fluvial morphologies are mainly meande

关键词： Qaidam basin Remote sensing UAV Distributive fluvial system Fluvial morphology Dryland fluvial systems

Research on manufacture technology of spherical fuel elements by dry-bag isostatic pressing

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Nuclear Science and Techniques 2022年第10期33卷 79-89页

作者： Zhen-Ming Lu wen-Ke Zhang jie Zhang xiang-wen Zhou Kai-Hong Zhang Ma-Lin Liu Xuan-Ke Li Bing Liu Hubei Province Key Laboratory of Coal Conversion and New Carbon Materials Wuhan University of Science and TechnologyWuhan 430081China Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyTsinghua UniversityBeijing 100084China

The steady development of high-temperature gas-cooled reactors(HTRs) has increased the requirements for the production cost and quality of fuel elements. Green fuel element pressing is one of the key steps to increase the production capacity. This paper proposes a proprietary vacuum dry-bag isostatic pressing(DIP) apparatus. The structural change of the matrix graphite powder during the DIP process was examined by analyzing the density change of the matrix graphite spheres with pressure. The soft molding process was simulated using the finite element method. The dimensional changes in the spheres during the pressing, carbonization, and purification stages were explored. The performance of the fuel matrix produced by the DIP method was comprehensively examined. The fuel matrix met the technical requirements and its anisotropy was significantly reduced. The DIP method can significantly improve both the production efficiency and quality of fuel elements. This will play a key role in meeting the huge demand for fuel elements of HTRs and molten salt reactors.

关键词： Dry-bag isostatic pressing High-temperature gas-cooled reactor(HTR) Spherical fuel element Finite element simulation Soft molding

A Structure-Preserving JKO Scheme for the SizeModified Poisson-Nernst-Planck-Cahn-Hilliard Equations

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Numerical Mathematics(Theory,Methods and Applications) 2023年第1期16卷 204-229页

作者： jie Ding xiang Ji School of Science Jiangnan UniversityWuxiJiangsu214122China Department of Mathematics and Mathematical Center for Interdiscipline Research Soochow University1 Shizi StreetSuzhou 215006JiangsuChina

In this paper,we propose a structure-preserving numerical scheme for the size-modified Poisson-Nernst-Planck-Cahn-Hilliard(SPNPCH)equations derived from the free energy including electrostatic energies,entropies,steric energies,and Cahn-Hilliard *** on the Jordan-Kinderlehrer-Otto(JKO)framework and the Benamou-Brenier formula of quadratic Wasserstein distance,the SPNPCH equations are transformed into a constrained optimization *** exploiting the convexity of the objective function,we can prove the existence and uniqueness of the numerical solution to the optimization *** conservation and unconditional energy-dissipation are preserved automatically by this ***,by making use of the singularity of the entropy term which keeps the concentration from approaching zero,we can ensure the positivity of *** solve the optimization problem,we apply the quasi-Newton method,which can ensure the positivity of concentration in the iterative *** tests are performed to confirm the anticipated accuracy and the desired physical properties of the developed ***,the proposed scheme can also be applied to study the influence of ionic sizes and gradient energy coefficients on ion distribution.

关键词： Structure-preserving size-modified Poisson-Nernst-Planck-Cahn-Hilliard equations JKO framework positivity

The effect of the density difference between supercritical CO_(2) and supercritical CH_(4) on their adsorption capacities: An experimental study on anthracite in the Qinshui Basin

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Petroleum Science 2022年第4期19卷 1516-1526页

作者： Si-jie Han Shu-Xun Sang Piao-Piao Duan Jin-Chao Zhang wen-Xin xiang Ang Xu Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization China University of Mining and TechnologyXuzhouJiangsu221008China Carbon Neutrality Institute China University of Mining and Technology XuzhouJiangsu221008China School of Resources and Geosciences China University of Mining and TechnologyXuzhouJiangsu221116China

Deep unmineable coals are considered as economic and effective geological media for CO_(2) storage and CO_(2) enhanced coalbed methane(CO_(2)-ECBM) recovery is the key technology to realize CO_(2) geological sequestration in coals. Anthracite samples were collected from the Qinshui Basin and subjected to mercury intrusion porosimetry, low-pressure CO_(2) adsorption, and high-pressure CH_(4)/CO_(2) isothermal adsorption experiments. The average number of layers of adsorbed molecules(ANLAM) and the CH_(4)/CO_(2) absolute adsorption amounts and their ratio at experimental temperatures and pressures were calculated. Based on a comparison of the density of supercritical CO_(2) and supercritical CH_(4), it is proposed that the higher adsorption capacity of supercritical CO_(2) over supercritical CH_(4) is the result of their density differences at the same temperature. Lastly, the optimal depth for CO_(2)-ECBM in the Qinshui Basin is recommended. The results show that:(1) the adsorption capacity and the ANLAM of CO_(2) are about twice that of CH_(4) on SH-3 anthracite. The effect of pressure on the CO_(2)/CH_(4) absolute adsorption ratio decreases with the increase of pressure and tends to be consistent.(2) A parameter(the density ratio between gas free and adsorbed phase(DRFA)) is proposed to assess the absolute adsorption amount according to the supercritical CO_(2)/CH_(4) attributes. The DRFA of CO_(2) and CH_(4) both show a highly positive correlation with their absolute adsorption amounts, and therefore, the higher DRFA of CO_(2) is the significant cause of its higher adsorption capacity over CH_(4) under the same temperature and pressure.(3) CO_(2) adsorption on coal shows micropore filling with multilayer adsorption in the macro-mesopore, while methane exhibits monolayer surface coverage.(4) Based on the ideal CO_(2)/CH_(4) competitive adsorption ratio, CO_(2) storage capacity, and permeability variation with depth, it is recommended that the optimal depth for CO_(

关键词： CO_(2)geological storage Competitive adsorption Deep unmineable coal Average number of layers of adsorbed molecules Density ratio between free phase and adsorbed phase Micropore filling

铸牢中华民族共同体意识研究回溯与展望(2017—2023)——基于CiteSpace的可视化分析

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三峡大学学报（人文社会科学版） 2025年第1期47卷 29-40,56页

作者：龚志祥谭雯心东北大学秦皇岛分校民族学学院河北秦皇岛066004

本文运用CiteSpace软件绘制可视化知识图谱,分析2017—2023年中国知网CNKI核心期刊(北大核心、CSSCI期刊)铸牢中华民族共同体意识研究领域的1 772篇高质量文献,从发文量及趋势、作者及机构、引用量及高频关键词、多学科跨学科及研究机... 详细信息

本文运用CiteSpace软件绘制可视化知识图谱,分析2017—2023年中国知网CNKI核心期刊(北大核心、CSSCI期刊)铸牢中华民族共同体意识研究领域的1 772篇高质量文献,从发文量及趋势、作者及机构、引用量及高频关键词、多学科跨学科及研究机构合作等进行分析。铸牢中华民族共同体意识研究的发文量自2017年始逐年增长,经过快速上升,达到高水平的平稳增长。铸牢中华民族共同体意识理论体系研究深化仍是热点,实践研究与政策响应研究需进一步拓展和深化。

关键词：铸牢中华民族共同体意识 CiteSpace可视化分析研究现状

Long-term improvements in water conservation functions at Qilian Mountain National Park, northwest China

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Journal of Mountain Science 2023年第10期20卷 2885-2897页

作者： GAO xiang HUANG Xing-xing CHANG Shu-hang DANG Qian-wen wen Rui-yang LO Kevin LI jie YAN An College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China Department of Geography Hong Kong Baptist UniversityHong Kong 999077China

Water conservation is one of the most important ecosystem *** study uses the InVEST model to examine the water conservation function of the Qilian Mountain National Park(QMNP),an important water supply area in northwest *** analyzed the spatiotemporal water conservation patterns of QMNP from 1988 to *** showed that the water conservation capacity in QMNP has increased over the past 32 years,reaching a peak of 6.495×108 m3 in *** area with an increased water conservation capacity is 12 times larger than the area with a reduced *** also examined how climatic,land-use,vegetation coverage,and topographical factors influence water conservation *** found that precipitation is the main climatic factor in water *** water conservation function also varies with land-cover type,with forests having the highest capacity,followed by ***,topographical factors,including altitude and slope,also shape the spatial patterns of water conservation functions in QMNP.

关键词： Water conservation function Ecosystem services InVEST model Qilian Mountain National Park Northwest China

Multi-objective optimization and experiment of nylon cord rubber in expandable packer

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Petroleum Science 2021年第1期18卷 269-284页

作者： Yan-wen Zhang Han-xiang Wang Jia-Qi Che Ming-Chao Du Hong-jie Zhang College of Mechanical and Electronic Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina

Nylon cord rubber has the advantages of small residual deformation and is easy to lift and lower the tubing string in low-permeability oil and gas ***,it is associated with low-pressure resistance and poor sealing *** enhance the performance of nylon cord rubber,a three-dimensional numerical model of the nylon cord rubber was established and its accuracy experimentally *** Plackett-Burman test,the Steepest climbing test and the Response surface method were used to acquire the polynomial response surface model connecting structural parameters with bearing and sealing *** genetic algorithms,optimal structural parameters of nylon cord rubber were determined depending on field *** reliability of the optimized results was verified by laboratory *** was shown that after optimization,the bearing capacity of the expandable packer increased by 25%while the sealing performance increased by 66%.In addition,the bearing pressure was 70 MPa while the sealing pressure was 50 *** measurements effectively met the on-site requirements of high-pressure and fine fracturing in low-permeability oil and gas reservoirs.

关键词： Low-permeability reservoirs Nylon cord rubber Numerical simulation Response surface method Multi-objective genetic algorithm Laboratory test

High-order numerical method for the derivative nonlinear Schrodinger equation

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International Journal of Modeling, Simulation, and Scientific Computing 2017年第1期8卷 258-270页

作者： Shu-Cun Li xiang-Gui Li Jun-jie Cao wen-Bo Li School of Applied ScienceBeijing Information Science and Technology UniversityBeijing 100192P.R.China

In this work,a fourth-order numerical scheme in space and two second-order numerical schemes in both time and space are proposed for the derivative nonlinear Schrodinger *** verify the mass conservation for the two-level implicit *** influence on the soliton solution by adding a small random perturbation to the initial condition is *** numerical experiments are given to test the accuracy order for different schemes,*** also test the conservative property of mass and Hamiltonian for these schemes from the numerical point of view.

关键词： Derivative nonlinear Schrodinger equation finite difference soliton solution random perturbation

Interdecadal Variations of the March Atmospheric Heat Source over the Southeast Asian Low-Latitude Highlands

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Advances in Atmospheric Sciences 2023年第9期40卷 1584-1596页

作者： Dayong wen jie CAO Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion Yunnan UniversityKunming 650091China

Based on the fifth-generation reanalysis dataset from the European Centre for Medium-Range Weather Forecasts for 1979–2019,we investigated the effects of the circumglobal teleconnection(CGT)on the interdecadal variation of the March atmospheric heat source(AHS)over the Southeast Asian low-latitude highlands(SEALLH).The dominant mode of the March AHS over the SEALLH features a monopole structure with an 8–11-year *** variations in the AHS make an important contribution to the 11-year low-pass filtered component of the AHS index,whichexplains 54.3%of the total *** CGT shows a clear interdecadal variation,which explains 59.3%of the total *** March AHS over the SEALLH is significantly related to the CGT on interdecadal *** the CGT is optimally excited by a significant cyclonic vorticity source near northern Africa(i.e.,in its positive phase),the SEALLH is dominated by anomalous southerly winds and ascending motions on the east of the anomalous *** enhanced advection and upward transfer result in a high-enthalpy air mass that converges into and condenses over the SEALLH,leading to a largerthan-average March AHS over this *** key physical processes revealed by this diagnostic analysis are supported by numerical experiments.

关键词： interdecadal variation atmospheric heat source circumglobal teleconnection low-latitude highlands Rossby wave source