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含甲烷水合物沉积层渗透率特性实验与理论研究 被引量:10
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作者 刘瑜 陈伟 +3 位作者 宋永臣 杨明军 李清平 喻西崇 《大连理工大学学报》 EI CAS CSCD 北大核心 2011年第6期793-797,共5页
含水合物沉积层的饱和度与渗透率关系研究,是深水油气及海洋水合物资源勘探开发的基础性工作.利用两种平均粒径分别为0.110和0.210mm的玻璃砂模拟沉积层环境,通过体积测量法确定其孔隙度分别为0.364和0.368.测量甲烷水合物在沉积层中渗... 含水合物沉积层的饱和度与渗透率关系研究,是深水油气及海洋水合物资源勘探开发的基础性工作.利用两种平均粒径分别为0.110和0.210mm的玻璃砂模拟沉积层环境,通过体积测量法确定其孔隙度分别为0.364和0.368.测量甲烷水合物在沉积层中渗透率随饱和度的变化,并将得到的结果与平行毛细管模型、Kozeny颗粒模型以及Masuda模型进行了比较.结果表明:模拟的沉积层可以近似认为是等径球体颗粒堆积物,其渗透率与孔隙度基本符合修正的Kozeny-Carman公式关系;沉积层中甲烷水合物的存在使其渗透率急剧下降;与多个模型比较后发现水合物占据孔隙中心的平行毛细管模型与实验结果吻合得较好,说明实验中甲烷水合物主要是在沉积层的孔隙中生成而不是对玻璃砂颗粒形成包络;甲烷水合物饱和度低于25%的沉积层渗透率与饱和度的关系成指数递减关系. 展开更多
关键词 甲烷水合物 模拟沉积层 饱和度 渗透率 Kozeny-Carman公式 平行毛细管模型
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Modeling of Hillslope Runoff and Soil Erosion at Rainfall Events Using Cellular Automata Approach 被引量:13
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作者 MA Ting ZHOU Cheng-Hu CAI Qiang-Guo 《Pedosphere》 SCIE CAS CSCD 2009年第6期711-718,共8页
A novel quantitative cellular automata (CA) model that simulates and predicts hillslope runoff and soil erosion caused by rainfall events was developed by integrating the local interaction rules and the hillslope surf... A novel quantitative cellular automata (CA) model that simulates and predicts hillslope runoff and soil erosion caused by rainfall events was developed by integrating the local interaction rules and the hillslope surface hydraulic processes. In this CA model, the hillslope surface was subdivided into a series of discrete spatial cells with the same geometric features. At each time step, water and sediment were transported between two adjacent spatial cells. The flow direction was determined by a combination of water surface slope and stochastic assignment. The amounts of interchanged water and sediment were computed using the Chezy-Manning formula and the empirical sediment transport equation. The water and sediment discharged from the open boundary cells were considered as the runoff and the sediment yields over the entire hillslope surface. Two hillslope soil erosion experiments under simulated rainfall events were carried out. Cumulative runoff and sediment yields were measured, respectively. Then, the CA model was applied to simulate the water and soil erosion for these two experiments. Analysis of simulation results indicated that the size of the spatial cell, hydraulic parameters, and the setting of time step and iteration times had a large impact on the model accuracy. The comparison of the simulated and measured data suggested that the CA model was an applicable alternate for simulating the hillslope water flow and soil erosion. 展开更多
关键词 hillslope surface hydraulic parameters SEDIMENT simulation water
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Calcium phosphate deposition on surface of porous and dense TiNi alloys in simulated body fluid 被引量:1
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作者 刘珏 刘超 +2 位作者 李婧 刘敏 阮建明 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第1期1-9,共9页
Porous and dense TiNi alloys were successfully fabricated by powder metallurgy(P/M) method, and to further improve their surface biocompatibility, surface modification techniques including grind using silicon-carbide(... Porous and dense TiNi alloys were successfully fabricated by powder metallurgy(P/M) method, and to further improve their surface biocompatibility, surface modification techniques including grind using silicon-carbide(SiC) paper, acid etching and alkali treatment were employed to produce either irregularly rough surface or micro-porous surface roughness. X-ray diffractometry(XRD), scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDX) attached to SEM were used to characterize surface structure and the Ca-P coatings. Effects of the above surface treatments on the surface morphology, apatite forming ability were systematically investigated. Results indicate that all the above surface treatments increase the apatite forming ability of TiNi alloys in varying degrees when soaked in simulated body fluid(SBF). More apatite coatings formed on TiNi samples sintered at 1050℃ and 1100℃ due to their high porosity and pure TiNi phase that is beneficial to heterogeneous nucleation. Furthermore, more uniform apatite was fabricated on the sample sintered from the mixture of Ni and Ti powders. 展开更多
关键词 calcium phosphate TiNi alloy surface treatment MICROSTRUCTURE simulated body fluid (SBF)
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两则自制教具的设计与制作
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作者 徐正文 《教学仪器与实验(小学版)》 2004年第1期27-28,共2页
关键词 自制教具 设计思路 制作方法 《化石》 沉积层模拟筒》 小学 科学教学
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Numerical simulation of pollution process due to resuspension of bed materials adsorbing pollutants in alluvial rivers 被引量:2
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作者 DING Yun XIAO Yang ZHONG DeYu 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第7期1280-1288,共9页
Resuspension of bed materials absorbing pollutants potentially poses unpredictable challenges to water management in alluvial rivers and its mechanism of transport has not been widely recognized.In this study,a transp... Resuspension of bed materials absorbing pollutants potentially poses unpredictable challenges to water management in alluvial rivers and its mechanism of transport has not been widely recognized.In this study,a transport equation that defines the movement of pollutants adsorbed on the bed materials in the active bed layer is established,on the basis of mass conservation law and continuum theory.The transport equation is coupled into the 1-D mathematical model to numerically investigate water pollution process due to the scour of the bed sediment adsorbing pollutants.Comparisons with the situation in which the dynamics of the active bed layer is not considered indicate that the periodical evolution of the bed layer plays an innegligible role in the pollution process due to sediment re-suspension.Furthermore,comparisons of the results with available experimental observations are presented,and fairly good agreement is obtained. 展开更多
关键词 RESUSPENSION POLLUTANTS alluvial rivers active bed layer
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