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Definition of the general initial water penetration fracture criterion for concrete and its engineering application

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science China(Technological sciences) 2011年第6期54卷 1575-1580页

作者： JIANG YaZhou REN QingWen XU Wei LIU shuang college of Water Conservancy and Hydropower engineering Hohai University Nanjing 210098 China college of Mechanics and Material Hohai University Nanjing 210098 China

A general initial water penetration(seepage) fracture criterion for concrete is proposed to predict whether or not harmful water penetration(hydraulic fracturing),other than microcracking,will occur in concrete structures in a severe high water pressure *** final regression,of the different macroscopic failure types in concrete to microscopic ModeⅠ c racking,allows the use of only one universal criterion to indicate the ***,a general initial water penetration fracture criterion is approximately defined as a strain magnitude of 1000×10-6,based on the concept of tensile strain derived from experimental results in the relevant ***,the locations of harmful water penetration fracture(hydraulic fracture) in the high arch dam mass of the Jinping first class hydropower project are analyzed using the nonlinear finite element method(FEM) according to the proposed *** proposed criterion also holds promise for other concrete structures in high water pressure environments.

关键词： concrete initial water penetration fracture criterion hydraulic fracture tensile strain Jinping high arch dam

Quantitative proteomics revealed extensive microenvironmental changes after stem cell transplantation in ischemic stroke

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Frontiers of Medicine 2022年第3期16卷 429-441页

作者： Yao Chen Fahuan song Mengjiao Tu shuang Wu Xiao He Hao Liu Caiyun Xu Kai Zhang Yuankai Zhu Rui Zhou Chentao Jin Ping Wang Hong Zhang Mei Tian Department of Nuclear Medicine and Medical PET Center The Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Institute of Nuclear Medicine and Molecular Imaging Zhejiang UniversityHangzhou 310009China Key Laboratory of Medical Molecular Imaging of Zhejiang Province Hangzhou 310009China Shanxi Medical University Taiyuan 030001China Key Laboratory for Biomedical engineering of Ministry of Education Zhejiang UniversityHangzhou 310027China college of Biomedical engineering and Instrument science Zhejiang UniversityHangzhou 310027China Department of Radiology Zhejiang HospitalHangzhou 310030China Department of PET Center The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310006China

The local microenvironment is essential to stem cell-based therapy for ischemic stroke,and spatiotemporal changes of the microenvironment in the pathological process provide vital clues for understanding the therapeutic ***,relevant studies on microenvironmental changes were mainly confined in the acute phase of stroke,and long-term changes remain *** study aimed to investigate the microenvironmental changes in the subacute and chronic phases of ischemic stroke after stem cell ***,induced pluripotent stem cells(iPSCs)and neural stem cells(NSCs)were transplanted into the ischemic brain established by middle cerebral artery occlusion *** emission tomography imaging and neurological tests were applied to evaluate the metabolic and neurofunctional alterations of rats transplanted with stem *** proteomics was employed to investigate the protein expression profiles in iPSCs-transplanted brain in the subacute and chronic phases of *** with NSCs-transplanted rats,significantly increased glucose metabolism and neurofunctional scores were observed in iPSCs-transplanted *** proteomic data of iPSCs-transplanted rats identified a total of 39 differentially expressed proteins in the subacute and chronic phases,which are involved in various ischemic stroke-related biological processes,including neuronal survival,axonal remodeling,antioxidative stress,and mitochondrial function *** together,our study indicated that iPSCs have a positive therapeutic effect in ischemic stroke and emphasized the wide-ranging microenvironmental changes in the subacute and chronic phases.

关键词： ischemic stroke microenvironment induced pluripotent stem cells(iPSCs) positron emission tomography(PET) quantitative proteomics

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屯兰区块煤层气井压裂特征多尺度分析

煤炭科学技术 2024年第3期52卷 148-158页

作者：李鸿雨宋晓夏刘威李伟陈伟东王昱太原理工大学矿业工程学院山西太原030024 煤与煤系气地质山西省重点实验室山西太原030024 山西焦煤集团有限责任公司屯兰煤矿山西古交030200 东北石油大学非常规油气研究院黑龙江大庆163318

为探究屯兰区块煤层气井压裂特征,以太原西山屯兰区块2号煤层为研究对象,通过对采煤工作面揭露的XST-167、XST-168、XST-176和XST-177四口煤层气井进行地质编录、煤样宏观特征描述及CT分析,从多尺度研究煤层的压裂特征。结果表明:研究... 详细信息

为探究屯兰区块煤层气井压裂特征,以太原西山屯兰区块2号煤层为研究对象,通过对采煤工作面揭露的XST-167、XST-168、XST-176和XST-177四口煤层气井进行地质编录、煤样宏观特征描述及CT分析,从多尺度研究煤层的压裂特征。结果表明:研究区煤层气井附近煤层主要分布斜交裂隙组成的“X”型压裂裂隙,在XST-177煤层气井附近有“T”型压裂裂隙。石英砂与压裂裂隙壁碰撞、摩擦产生煤粉,煤粉充填在裂隙内,对煤层气的产出有阻碍作用。通过对XST-168、XST-177二口煤层气井揭露的井筒进行对比,发现XST-177煤层气井的压裂效果更好,更有利于煤层气的产出。煤层气井附近的煤大多为碎裂煤、碎粒煤,水力压裂破坏了煤体的原生结构,使煤体硬度降低,裂隙显著增加。部分煤样可以观测到石英砂镶嵌其上,主要集中在煤的层理面上,说明石英砂被压进煤层后,主要沿水平缝向煤层内延伸,与此处的最大主应力方向保持一致。通过CT扫描技术,对受压裂影响的煤样(压裂煤)和未受压裂影响的煤样(正常煤)进行扫描,发现压裂煤T1、T2中裂隙宽度大于100μm的裂隙分别占总裂隙体积的58.8%和48.5%,裂隙数量上分别为23407条和19679条,而正常煤T3中裂隙宽度大于100μm的裂隙仅占总裂隙体积的1.7%,裂隙数量仅为3504条,T1、T2较T3的裂隙宽度更宽,裂隙数量更多,说明压裂作用使煤样裂隙宽度和数量明显增加,压裂煤内部的孔裂隙更发育。

关键词：煤层气屯兰区块多尺度水力压裂裂隙计算机断层扫描技术

BIODEGRADATION OF ALOGENATED ANILINES IN RIVER WATER

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BIODEGRADATION OF ALOGENATED ANILINES IN RIVER WATER

16th IAHR-APD Congress and 3rd Symposium of IAHR-ISHS

作者： Guanghua Lu①, Wenting song①, Bijun Xu②, Chao Wang① ① Key Laboratory for Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, college of Environmental science and engineering, Hohai University, Nanjing 210098, China, ② Shanghai Academy of Environmental engineering and Designing sciences, Shanghai 200232, China

The dominant complex bacteria isolated and incubated from the sludge collected from the sewage treatment work of Nanjing Chemical Plant (Jiangsu Province, China) could utilize halogenated anilines as sole carbon source and energy source. The complex bacteria were identified, consisting of, Kurthia, Ochrobaltrum, Xanthomonas, Brevibacterium, Alcaligenes and Fusarium sp. Using domesticated complex bacteria as an inoculum, the biodegradability of six halogenated anilines was determined by shaking-flask test under various aquatic conditions. The degradation rate of aborigine microbe in natural water to all target compounds was unsatisfied, and the complex bacteria exhibited higher metabolic efficiency on chemicals studied than the aborigine microbe. The metabolismic relationships of the dominant mixed bacteria and river bacteria were studied and there were synergetic effects for 4-bromaniline and competitive effects for the other compounds studied. The cometabolic degradation of mixed anilines was determined and the degradation course of binary mixtures was divided by two stages.

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银川平原地下水化学成因机制与组分来源解析

环境科学 2024年第8期45卷 4577-4588页

作者：韩双宝周殷竹郑焰周金龙李长青韩强强李甫成中国地质调查局水文地质环境地质调查中心天津300304 哈尔滨工业大学环境学院哈尔滨150090 南方科技大学环境科学与工程学院深圳518055 新疆农业大学水利与土木工程学院乌鲁木齐830052 中国地质环境监测院北京100081 宁夏回族自治区水文环境地质调查院银川750021

地下水是银川平原生活生产和农业灌溉的主要水源之一.受区域环境背景的影响以及人类活动的长期作用,地下水水质整体较差.为了深入分析银川平原地下水水化学成因机制并解析水化学组分来源,采用传统的水化学图解法与数理统计法和主成分分... 详细信息

地下水是银川平原生活生产和农业灌溉的主要水源之一.受区域环境背景的影响以及人类活动的长期作用,地下水水质整体较差.为了深入分析银川平原地下水水化学成因机制并解析水化学组分来源,采用传统的水化学图解法与数理统计法和主成分分析-多元线性统计模型,基于100组潜水和46组承压水样品的无机组分含量,分析了潜水和承压水水化学特征与质量状况、超标毒理组分的空间分布以及水化学组分来源贡献率.结果表明:①地下水水化学成分受岩石风化和蒸发浓缩作用的共同控制.②溶滤-富集作用(F1)、原生地质环境(F2)和人类活动因素(F3)是影响研究区地下水的主要因素,其对地下水化学组分来源的贡献率分别为73.67%、14.45%和11.88%.③地下水超标的主要毒理指标为NO_(3)^(-)-N和F^(-);农业活动对区内高NO_(3)^(-)-N潜水的贡献较大,其次为生活污水的排放;含F矿物溶滤与阳离子交换吸附作用是地下水中F^(-)富集的主要因素.

关键词：地下水来源解析硝酸盐氟化物成因分析银川平原

MoS_(2)/ZnO纳米复合材料的光学和光催化性能

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化工进展 2021年第7期40卷 3870-3877页

作者：李酽宋双连晓雪中国民航大学理学院天津300300

在溶剂热法制备ZnO纳米粒子的基础上,利用物理剥离和纳米粒子互剪切作用成功制备了MoS_(2)/ZnO异质结构纳米复合物。以扫描电子显微镜、透射电子显微镜、X射线能量色散光谱、粉末X射线衍射、拉曼光谱仪、紫外-可见漫反射光谱、光致发光... 详细信息

在溶剂热法制备ZnO纳米粒子的基础上,利用物理剥离和纳米粒子互剪切作用成功制备了MoS_(2)/ZnO异质结构纳米复合物。以扫描电子显微镜、透射电子显微镜、X射线能量色散光谱、粉末X射线衍射、拉曼光谱仪、紫外-可见漫反射光谱、光致发光谱等对样品进行了结构形貌和性能表征。结果表明,利用物理剥离和互剪切作用能有效地获得MoS_(2)/ZnO复合物,复合作用使得MoS_(2)位于378cm^(-1)(E^(1)_(2g))和400cm^(-1)(A_(1g))处的两个特征拉曼峰显著增强。复合物中MoS_(2)含量越少,两个特征拉曼峰强度反而越高,且两峰波数间隔相应减小。可归因于MoS_(2)含量较低时,ZnO纳米粒子对MoS_(2)的物理剥离效果越显著,同时,MoS_(2)体现出良好的分散性和较小的厚度。MoS_(2)含量对MoS_(2)/ZnO的发光具有明显的调制作用,显著增强了复合物在可见光区域的吸收。随着MoS_(2)含量增加,其可见光发光强度迅速减小,紫外峰出现明显的蓝移。纯ZnO对苯酚的降解率最高达90%,而MoS_(2)/ZnO复合物对苯酚的降解率达100%,复合物对苯酚的最终降解率明显高于纯氧化锌。

关键词：纳米材料复合材料纳米粒子异质结构光化学拉曼光谱光催化性能

Simple synthesis of sub-nanometer Pd clusters:High catalytic activity of Pd/PEG-PNIPAM in Suzuki reaction

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Chinese Journal of Catalysis 2017年第4期38卷 651-657页

作者： Zhe Chen Yu Liang Da‐shuang Jia Zhi‐Min Cui Wei‐Guo song college of Environmental science and engineering North China Electric Power University Beijing 102206 China School of Chemistry and Environment Beihang University Beijing 100191 China Laboratory of Molecular Nanostructure and Nanotechnology Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

Ultra‐small metal nanoclusters have high surface energy and abundant active sites,and thereforetheir catalytic activities are usually significantly higher than those of larger nanoparticles.A temperature‐responsive copolymer,namely poly(ethylene glycol)‐co‐poly(N‐isopropylacrylamide)(PEG‐PNIPAM)was synthesized as the first step,and then ultra‐small Pd clusters stabilized withinPEG‐PNIPAM copolymer micelles were formed by direct *** nanoclusters of size less than2nm showed outstanding catalytic activity in the Suzuki coupling *** reaction betweeniodobenzene and phenylboronic acid was completed in as little as10s(turnover frequency=4.3×104h?1).A yield of64%was achieved in5min in the reaction between chlorobenzene and *** catalyst showed significant deactivation during three consecutive ***,this composite catalyst consisting of Pd/PEG‐PNIPAM can be easily recycled based on the reversiblephase transition of temperature‐responsive PEG‐*** catalyst therefore has good potentialfor practical applications.

关键词： Temperature responsive Hydrophilic polymer Pd nanoclusters Suzuki reaction

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多级水力压裂应力阴影效应的数值分析

矿业科学学报 2024年第3期9卷 475-482页

作者：宋进鑫郁航王雅亭陈佳亮鞠杨中国矿业大学(北京)力学与土木工程学院北京100083 深圳大学土木与交通工程学院广东深圳518060 煤炭精细勘探与智能开发国家重点实验室北京100083

多级水力压裂作为储层改造的主要技术手段,广泛用于提高致密油气藏的气体产量。裂缝在扩展过程中的应力阴影效应对于有效连通储层的天然裂缝并形成有利于油、气体流动的复杂裂缝网络至关重要。本研究采用了自适应的有限元-离散元方法,... 详细信息

多级水力压裂作为储层改造的主要技术手段,广泛用于提高致密油气藏的气体产量。裂缝在扩展过程中的应力阴影效应对于有效连通储层的天然裂缝并形成有利于油、气体流动的复杂裂缝网络至关重要。本研究采用了自适应的有限元-离散元方法,通过改进网格自动细化和识别多个裂缝扩展模拟含天然裂缝储层的多级水力压裂。数值模型中考虑了水力裂缝、天然裂缝和微观孔隙结构的相互作用,整合了非线性的Carter滤失模型来描述多级压裂过程中压裂液的滤失效应。引入了理想平行板流的支撑剂运输方程,并采用了达西定律来分析裂缝网络中的流体渗透效应。通过比较无裂缝均质模型和天然裂缝模型的裂缝网络和流体流动,评估了天然裂缝对多级压裂裂缝行为和气体产量的影响。研究为确定和优化致密气藏中压裂簇间距提供了一种新的方法。

关键词：自适应有限元-离散元法应力阴影效应流体力学耦合压裂液滤失效应

维普期刊数据库博看期刊

Experimental study on piping in sandy gravel foundations considering effect of overlying clay

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Water science and engineering 2016年第2期9卷 165-171页

作者： shuang Wang Jian-sheng Chen Hai-qing He Wen-zheng He college of Civil and Transportation engineering Hohai University college of Earth sciences and engineering Hohai University

The influence of the overlying clay on the progression of piping in the sandy gravel foundation of water-retaining structures is often neglected. In order to study this influence, an experimental investigation was conducted on a laboratory-scale model. It was discovered that the critical hydraulic gradient and the area of the piping tunnel increase when the overlying clay thickens. With a thicker clay layer, erosion of the sandy gravel below the clay layer occurs later, but, once the erosion starts, the erosion rate is very high and the average velocity of water seeping through the cross-section of the sandy gravel increases rapidly due to the low deformability of the thick clay layer. Furthermore, it was found that the progression of piping is a complicated and iterative process involving erosion of fine particles, clogging of pores, and flushing of the clogged pores. Two types of erosion have been identified in the progression of piping: one causes the tunnel to advance upstream, and the other increases the depth of the tunnel. The results show that the overlying clay is an important factor when evaluating piping in sandy gravel foundations of water-retaining structures.

关键词： Piping Experimental model Sandy gravel foundation Overlying clay Clog Erosion rate