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EXPERIMENTAL STUDY OF AIRFLOW INDUCED BY PUMPING TESTS IN UNCONFINED AQUIFER WITH LOW-PERMEABILITY CAP

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Journal of Hydrodynamics 2012年第4期24卷 605-608页

作者： HUANG Hui qian jia-zhong KUANG Xing-xing CHEN Zhou LI Ru-zhong School of Resources and Environmental Engineering Hefei University of Technology Hefei 230009 China Department of Earth Sciences The University of Hong Kong Hong Kong China

The airflow in unsaturated soils is an issue of great importance in various fields such as in agricultural, nuclear, environmental engineering. However, up to now, little attention was paid to the generation of the airflow induced by a pumping test in an unconfined aquifer with a low-permeability cap and its influence on the pumping test. In this paper, pumping tests were carried out experimentally in the aquifer with a low-permeability cap in order to study the influence of the airflow induced by the pumping on the drawdown of the tests. It is shown that：（1） there is an airflow with negative pressure generated by the pumping tests, （2） the Negative air Pressure （NP） is increased with the pumping rate but decreased with the radial distance, and （3） the NP also changes with the initial water table. The results provide a good basis for further theoretical study of the airflow induced by pumping.

关键词： low-permeability cap pumping tests airflow unconfined aquifer drawdown

NON-LCL AND TRACER TEST FOR GROUNDWATER FLOW IN A SINGLE FRACTURE

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Journal of Hydrodynamics 2006年第1期18卷 104-108页

作者： qian jia-zhong LIU Yong WANG jian-hua GUAN Hou-chun CHEN Shi-jun WANG jia-quan School of Resources and Environmental Engineering Hefei University of Technology Hefei 230009China School of Biotechnology and Food Engineering Hefei University of Technology Hefei 230009 China

The validity of Local Cubic Law （LCL） is an important issue to study groundwater flow and transport in fractured media. According to laboratory simulaion tests, the average velocity with a lower gradient in a single fracture is calculated by the LCL, which is compared with the measured average velocity. Then dye tracer test is designed and completed. The evidence for non-LCL, is drawn from the results of the simulation tests and the dye tracer tests. Then the Reynolds number of groundwater is calculated, the critical value of Re for laminar flow is discussed in a single fracture under different conditions. The motion types for groundwater flow have been discussed.

关键词： non-Local Cubic Law (LCL) tracer test,groundwater flow in a single fracture

FUZZY MODEL FOR TWO-DIMENSIONAL RIVER WATER QUALITY SIMULATION UNDER SUDDEN POLLUTANTS DISCHARGED

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Journal of Hydrodynamics 2007年第4期19卷 434-441页

作者： LI Ru-zhong SHIGEKI Masunaga HONG Tian-qiu qian jia-zhong School of Resources and Environmental Engineering Hefei University of Technology Hefei 230009 China Graduate School of Environment and Information Sciences Yokohama National University Yokohama 240-8501 Japan

Based on the fuzziness and impreciseness of water environmental system, the fuzzy arithmetic was used to simulate the fuzzy and imprecise relations in modeling river water quality. By defining the parameters of water quality model as symmetrical triangular fuzzy numbers, a two-dimensional fuzzy water quality model for sudden pollutant discharge is established. From the fuzzy model, the pollutant concentrations, corresponding to the specified confidence level of a, can be obtained by means of the a-cut technique and arithmetic operations of triangular fuzzy numbers. Study results reveal that it is feasible in theory and reliable on calculation applying triangular fuzzy numbers to the simulation of river water quality.

关键词： fuzzy water quality simulation model triangular fuzzy number membership function a-cut technique

Experimental study on the velocity-dependent dispersion of the solute transport in different porous media

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Journal of Groundwater Science and Engineering 2019年第2期7卷 106-114页

作者： YAN Xiao-san qian jia-zhong MA Lei School of Resources and Environmental Engineering Hefei University of Technology

The hydrodynamic dispersion is an important factor influencing the reactive solute transport in the porous media, and many previous studies assumed that it linearly varied with the average velocity of the groundwater flow. Actually, such linear relationship has been challenged by more and more experimental observations, even in homogeneous media. In this study, we aim to investigate the relationship between hydrodynamics dispersion and the flow velocity in different types of porous media through a laboratory-controlled experiment. The results indicate that (1) the dispersion coefficient should not be a linear function of the flow velocity when the relationship between the flow velocity and the hydraulic gradient can be described by Darcy's law satisfactorily;(2) Power function works well in describing the dispersion coefficient changing with the flow velocity for different types of porous media, and the power value is between 1.0-2.0 for different particle sizes.

关键词： Solute transport Porous media Flow velocity Dispersion coefficient

EXPERIMENTAL STUDY OF FRICTION FACTOR FOR GROUNDWATER FLOW IN A SINGLE ROUGH FRACTURE

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Journal of Hydrodynamics 2009年第6期21卷 820-825页

作者： CHEN Zhou qian jia-zhong LUO Shao-he ZHAN Hong-bin School of Resources and Environmental Engineering Hefei University of Technology Hefei 230009 China Department of Resources and Environment Henan Polytechnic University Jiaozuo 454010 China Department of Geology and Geophysics Texas A and M University College Station TX 77843-3115 USA

To study the relationships between the friction factor f and the flow type in a single rough fracture, the formulae of f for both unconfined and confined flows are deduced based on previous studies. The relationships between f and the Reynolds number （Re） for different relative roughnesses are investigated experimentally. The Moody-type diagram, based on the deduced formula of f, is also plotted and the hydraulic characteristics of the flow in a rough fracture are analyzed. Results show that the Moody-type diagram of the experiment has a similar distribution to that of the conventional Moody diagram. It is found that the value of f in the experiment is much smaller than that of the conventional Moody diagram and turbulent flow appears easier for rough fractures, which can be explained by the separation phenomenon in boundary layers. The critical Re ranging from 650 to 700 in rough fractures is concluded based on the experimental results. It also can be concluded that the friction factor f is related not only with the Re and the relative roughness but also with the absolute roughness.

关键词： friction factor rough fracture Moody diagram critical Reynolds number ( Re ) boundary layer

Glial progenitor heterogeneity and plasticity in the adult spinal cord

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Neural Regeneration Research 2024年第12期19卷 2567-2568页

作者： Haichao Wei jia qian Wu Department of Neurosurgery McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTXUSA Center for Stem Cell and Regenerative Medicine UT Brown Foundation Institute of Molecular MedicineHoustonTXUSA MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences HoustonTXUSA

Glial progenitor cells were reported to have the capacity to generate various types of cells in both the central nervous system(CNS)and peripheral nervous *** progenitor cells can respond to diverse environmental signals and transform into distinct populations,each serving specific ***,the adult spinal cord hosts various populations of glial progenitors,a region integral to the central nervous *** development,glial progenitors express glial fibrillary acidic protein(GFAP;Dimou and Gotz,2014).However,the specific identities of GFAP-expressing progenitors in the adult spinal cord were not thoroughly investigated.

关键词： functions plasticity thoroughly

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基于指标体系的区域水资源合理配置初探

系统工程理论与实践 2005年第3期25卷 125-132页

作者：李如忠金菊良钱家忠汪家权合肥工业大学资源与环境工程学院安徽合肥230009 合肥工业大学土木建筑工程学院安徽合肥230009

根据评价指标筛选原则,设计了一个反映区域水资源-社会经济系统状况的多层次评价指标体系,建立了水资源合理配置的 GEM-AHP 计算模型.该模型是以水资源利用效果为目标,以社会、经济、资源、环境、技术和管理等领域的多个因子为评价指标... 详细信息

根据评价指标筛选原则,设计了一个反映区域水资源-社会经济系统状况的多层次评价指标体系,建立了水资源合理配置的 GEM-AHP 计算模型.该模型是以水资源利用效果为目标,以社会、经济、资源、环境、技术和管理等领域的多个因子为评价指标,根据方案层与目标层间的关系,将各个子区相对于水资源利用效果的组合权重之比作为各自应分摊的水量之比;再由各子区的人口数量信息,综合确定各自分配的水资源数量.实例研究表明,所建模型对涉及社会、经济、资源、环境、技术和管理等多领域的水资源分配问题具有很好的适用性.

关键词：水资源配置层次分析法群组决策特征根法评价指标体系

The rate dependence of the dielectric strength of dielectric elastomers

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International Journal of Smart and Nano Materials 2024年第1期15卷 110-126页

作者： Xianghe Zheng jianyou Zhou Pan jia Zheng zhong School of Science Harbin Institute of TechnologyShenzhenChina

Elastomers are widely used in electronics and electrical devices,either as insulators or *** insulation and actuation performance of elastomers are highly suscepti-ble to their dielectric *** the factors that influ-encethedielectricstrength ofelastomers,material viscoelasticity is an important factor that needs further *** the material viscoelasticity is often character-ized by rate-dependent behaviors,we present two different sample configurations to experimentally examine the electrical and mechanical rate dependence of the dielectric strength of VHB 4905 *** pre-stretch ratio of 4,the improve-ment of the dielectric strength is about 30%from voltage ramp of 50 V/s to 800 V/***,with an in-house biaxial test platform,the effect of the stretching rate on the dielectric strength is examined for the first *** improvement of the dielectric strength is about 35%from stretching rate of 0.1 mm/s to 5 mm/***,a dielectric strength predictor based on configurational stress is adopted to describe the experimental *** to the predictor,the loading rate affects the dielectric strength of the elastomer mainly by influencing the evolution of the inelastic deformation.

关键词： Dielectric strength dielectric elastomers material viscoelasticity rate-dependence configurational stress

Artificial intelligence-assisted design of new chemical materials: a perspective

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Science China(Information Sciences) 2024年第8期67卷 334-336页

作者： Feng qian Wenli DU Weimin zhong Yang TANG Jingyi LU Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and Technology

New chemical materials are a fresh category of substances created through chemical reactions or by refining existing materials through secondary processes. By using creative methods, advanced technologies, innovative techniques, and state-of-the-art equipment, these materials(e.g., high-end polyolefin, nano materials) [1] are carefully designed and developed to showcase outstanding performance and unique capabilities beyond what traditional chemical materials can offer [2].

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