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层状粘性土壤水分动态新模型的应用 被引量:7
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作者 任理 李春友 李韵珠 《中国农业大学学报》 CAS CSCD 北大核心 1998年第1期57-62,共6页
根据Moldrup等提出的运动平均斜率(movingmeanslope)模型,对重粘土、轻粘土、粉质粘土和壤土及前3种粘性土壤所构成的层状介质中的水分,在入渗条件下的运动进行了数值模拟。结果表明,这种新模型对粘性土壤水分动态的预报较传统有... 根据Moldrup等提出的运动平均斜率(movingmeanslope)模型,对重粘土、轻粘土、粉质粘土和壤土及前3种粘性土壤所构成的层状介质中的水分,在入渗条件下的运动进行了数值模拟。结果表明,这种新模型对粘性土壤水分动态的预报较传统有限差分数值模型简捷、快速。 展开更多
关键词 层状土壤 粘性质地 水分动态 模拟 模型
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ulti-azimuth three-component surface seismic modeling for viscoelastic cracked monoclinic media 被引量:6
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作者 Wang Enli Han Liguo Wang Deli 《Applied Geophysics》 SCIE CSCD 2007年第1期16-24,共9页
In this article, a method of high order, staggered grid, finite difference was used to model snapshots of seismic wave propagation and multi-azimuth surface seismic records in viscoelastic cracked monoclinic media. Th... In this article, a method of high order, staggered grid, finite difference was used to model snapshots of seismic wave propagation and multi-azimuth surface seismic records in viscoelastic cracked monoclinic media. The modeling results clearly show the anisotropy caused by the crack fill material and the viscoelastic wave field through the monoclinic media. Summarizing the regularity of seismic records for different azimuths, this study is a significant attempt to understand the wave fields propagated in real media and to propose a more rational theoretical model for the future. 展开更多
关键词 monoclinic anisotropy simulation variable azimuth finite difference.
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Research on Dynamic Parameters of Soil Sites in the Dalian Area
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作者 Zhang Xiaoping Li Ya +3 位作者 Liu Yang Jiang Hua Zhang Yinlong Huang Yimo 《Earthquake Research in China》 2012年第4期499-511,共13页
In this paper, dynamic soil parameters derived from Dalian area seismic risk assessment reports are collected. In this study, the measurement data is divided into 7 types, i.e. silty clay, muddy silty clay, clay, medi... In this paper, dynamic soil parameters derived from Dalian area seismic risk assessment reports are collected. In this study, the measurement data is divided into 7 types, i.e. silty clay, muddy silty clay, clay, medium sand, rock fragments, backfill soil and fully-weathered slate. Statistics of the dynamic parameters of these soils are carried out to obtain the mean values of dynamic shear modulus ratio and damping ratio. Typical drill holes are selected to establish dynamic soil models to investigate the seismic response for various cases. The dynamic parameters of the models are taken from the statistical values of this study, the standard values of code 94 (i.e. the dynamic soil parameters for Dalian seismic microzonation), and the recommended values by Yuan Xiaoming et al. (2000) respectively. The calculated results of peak ground acceleration are compared with the response spectral characteristics. The results show that the statistical values are approximate to the values recommended by Yuan Xiaoming, et al. (2000), but different greatly with the standard values in code 94. 展开更多
关键词 Site soil Dynamic soil parameter Dalian area
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Sorption of Water-Extractable Organic Carbon in Various Clay Subsoils: Effects of Soil Properties 被引量:5
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作者 Trung Ta NGUYEN Petra MARSCHNER 《Pedosphere》 SCIE CAS CSCD 2016年第1期55-61,共7页
Clay-rich subsoils are added to sandy soils to improve crop yield and increase organic carbon (C) sequestration; however, little is known about the influence of clay subsoil properties on organic C sorption and deso... Clay-rich subsoils are added to sandy soils to improve crop yield and increase organic carbon (C) sequestration; however, little is known about the influence of clay subsoil properties on organic C sorption and desorption. Batch sorption experiments were conducted with nine clay subsoils with a range of properties. The clay subsoils were shaken for 16 h at 4 ℃with water-extractable organic C (WEOC, 1 224 g C L-1) from mature wheat residue at a soil to extract ratio of 1:10. After removal of the supernatant, the residual pellet was shaken with deionised water to determine organic C desorption. The WEOC sorption was positively correlated with smectite and illite contents, cation exchange capacity (CEC) and total organic C, but negatively correlated with kaolinite content. Desorption of WEOC expressed as a percentage of WEOC sorbed was negatively correlated with smectite and illite contents, CEC, total and exchangeable calcium (Ca) concentrations and clay content, but positively correlated with kaolinite content. The relative importance of these properties varied among soil types. The soils with a high WEOC sorption capacity had medium CEC and their dominant clay minerals were smectite and illite. In contrast, kaolinite was the dominant clay mineral in the soils with a low WEOC sorption capacity and low-to-medium CEC. However, most soils had properties which could increase WEOC sorption as well as those that could decrease WEOC sorption. The relative importance of properties increasing or decreasing WEOC sorption varied with soils. The soils with high desorption had a low total Ca concentration, low-to-medium CEC and low clay content, whereas the soils with low desorption were characterised by medium-to-high CEC and smectite and illite were the dominant clay minerals. We conclude that WEOC sorption and desorption depend not on a single property but rather a combination of several properties of the subsoils in this study. 展开更多
关键词 cation exchange capacity clay mineral illite kaolinite SMECTITE
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