Performance of soil particle-size distribution models for describing deposited soils adjacent to constructed dams in the China Loess Plateau     

Pei Zhao  Ming-an Shao  Robert Horton 《Acta Geophysica》2011,59(1):124-138

Soil particle-size distributions (PSD) have been used to estimate soil hydraulic properties. Various parametric PSD models have been proposed to describe the soil PSD from sparse experimental data. It is important to determine which PSD model best represents specific soils. Fourteen PSD models were examined in order to determine the best model for representing the deposited soils adjacent to dams in the China Loess Plateau; these were: Skaggs (S-1, S-2, and S-3), fractal (FR), Jaky (J), Lima and Silva (LS), Morgan (M), Gompertz (G), logarithm (L), exponential (E), log-exponential (LE), Weibull (W), van Genuchten type (VG) as well as Fredlund (F) models. Four-hundred and eighty samples were obtained from soils deposited in the Liudaogou catchment. The coefficient of determination (R ²), the Akaike’s information criterion (AIC), and the modified AIC (mAIC) were used. Based upon R ² and AIC, the three- and four-parameter models were both good at describing the PSDs of deposited soils, and the LE, FR, and E models were the poorest. However, the mAIC in conjunction with R ² and AIC results indicated that the W model was optimum for describing PSD of the deposited soils for emphasizing the effect of parameter number. This analysis was also helpful for finding out which model is the best one. Our results are applicable to the China Loess Plateau.  相似文献   

Determination of Trace Silver in Polymetallic Ore Samples by Flame Atomic Absorption Spectrometry after Solid‐Phase Extraction Using a Microcolumn Comprising Eggshell Membrane     

Xianzhong Cheng  Kun Shao  Shangyue Shen  Shenghong Hu  Haiou Qiu 《Geostandards and Geoanalytical Research》2011,35(4):461-469

A rapid and inexpensive method was developed for the determination of trace silver in polymetallic ore samples by use of eggshell membrane (ESM), a natural biomaterial, as the solid‐phase extraction (SPE) adsorbent coupled with flame atomic absorption spectrometry (FAAS). The ESM was used for the separation/pre‐concentration of silver, and the parameters affecting sensitivity, such as pH, sample flow rate, eluent volume and eluent flow rate, were carefully investigated. ESM was found to be an effective solid phase extractant for the adsorption of trace silver over a wide range of acidity from 0.02 to 0.50 mol l^?1 HNO₃. The sample solution in 0.4 mol l^?1 HNO₃ was pumped through an ESM microcolumn at the rate of 1.0 ml min^?1. Silver was absorbed, and then eluted with a solution of 1.0% m/v thiourea–0.5% v/v HCl. Under these optimal conditions, ESM exhibited a good enrichment efficiency for silver with a dynamic adsorption capacity of 1.7 mg g^?1. The proposed method was applied to the FAAS determination of trace silver in polymetallic ores and geological reference materials, GSO‐2, 3 and 5, and GSD‐11, GSD‐12, and the determined values were in good agreement with certified values.  相似文献   

黔西织纳煤田上二叠统层序地层及聚煤作用   总被引：2，自引：0，他引：2  

郭立君  洪愿进  邵龙义  易同生  张卫平  汪浩 《古地理学报》2011,13(5):493-500

贵州西部织(织金)纳(纳雍)煤田以发育海陆过渡相含煤岩系而成为研究西南地区晚二叠世沉积相及层序地层的理想地区.作者对该煤田上二叠统含煤岩系(龙潭组和长兴组)进行了高分辨率层序地层分析,并探讨了层序地层格架下煤层厚度的变化规律.以区域不整合面以及下切谷砂体底部冲刷面等为层序界面,结合石灰岩标志层向古陆方向延伸距离而显示的...  相似文献   

广西合浦、南宁、宁明、百色盆地烃源岩有机地球化学特征与勘探潜力分析   总被引：2，自引：1，他引：1  

邵昌民  赵斌 《海相油气地质》2011,16(1):33-44

广西合浦、南宁、宁明等第三系盆地的主要烃源岩层与百色盆地一样,均是中始新统深湖-半深湖相暗色泥质岩层,特点是分布面积广,厚度大,有机质丰度高.有机碳含量多数大于2.0%,达到"好"到"最好"的评价标准.有机质成熟度多数处于低熟阶段,部分在成熟阶段.干酪根类型主要为Ⅱ1型.综合分析认为:合浦、南宁、宁明三个盆地都具有优质...  相似文献   

SPH modeling of tidal bore scenarios     

Liu  Huaxing  Li  Jing  Shao  Songdong  Tan  Soon Keat 《Natural Hazards》2015,75(2):1247-1270

Natural Hazards - The paper presented a smoothed particle hydrodynamics (SPH) method to study the three-dimensional (3D) tidal bore scenarios. The SPH method is a mesh-free particle modeling...  相似文献   

新疆拉伊克勒克斑岩铜矿3D电性结构与找矿指示     

邵陆森 《地质与勘探》2015,51(5):953-963

拉伊克勒克铜矿是最近在新疆东准噶尔地区发现的斑岩型铜多金属矿床,矿区地表为较厚的第四系覆盖,矿体主要赋存在隐伏英云闪长岩中,确定岩体的范围和三维形态是寻找矿体的关键环节。为了查明拉伊克勒克深部隐伏岩体的空间特征,为下一步勘探工作提供参考依据,在矿区进行了AMT探测,经过数据处理及反演得到了9条电阻率拟二维断面图。反演结果表明,拉伊克勒克深部隐伏岩体与上覆地层电阻率差异明显,呈现高阻特征;岩体外层的中阻层为找矿有利位置。通过对电阻率值进行3D克里金插值及可视化显示,建立了云英闪长岩体的3D电阻率模型,刻画了岩体的顶界面位置,揭示了岩体在深部的展布形态,为矿区下一步的找矿工作提供了参考依据。  相似文献   

南海始新世海相地层分布及油气地质意义          下载免费PDF全文

张浩  邵磊  张功成  陈淑慧  吴国瑄 《地球科学》2015,40(4):660-670

采用古生态学及沉积学方法, 对南海北部深水区BY7-1-1井及L29井特定层段进行细致研究.通过有孔虫、孢粉藻类分析及沉积学分析, 证实南海北部白云深水区在晚始新世即出现滨浅海相沉积环境, 确定了南海北部最早接受海相沉积的时间.始新世海相地层在南海北部主要分布在台西及台西南盆地中, 并在晚始新世扩展到珠江口盆地白云凹陷.在南部分布较广, 曾母盆地、北康盆地、礼乐盆地及巴拉望盆地中均有始新世海相地层分布.南海始新世海相地层的分布受制于新南海扩张及古南海的消退, 以晚始新世为时间节点发生显著变化, 总体上分布范围增大, 反映该时期南海拉张和断裂活动的加剧.南海始新世海相地层具有良好的油气潜力, 在部分盆地中形成了优质的烃源岩与储层, 珠江口盆地白云深水区晚始新世海相地层的发现, 对南海深水海相油气勘探具有积极的参考作用.   相似文献   

Differential response of Qilian juniper radial growth to climate variations in the middle of Qilian Mountains and the northeastern Qaidam Basin   总被引：1，自引：0，他引：1  

Wenzhi Wang  Xiaohong Liu  Xuemei Shao  Dahe Qin  Guobao Xu  Bo Wang  Xiaomin Zeng  Guoju Wu  Xuanwen Zhang 《Climatic change》2015,133(2):237-251

  相似文献   

Frequency analysis and its spatiotemporal characteristics of precipitation extreme events in China during 1951–2010     

Yuehong Shao  Junmei Wu  Jinyin Ye  Yonghe Liu 《Theoretical and Applied Climatology》2015,121(3-4):775-787

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Impact of sea spray on upper ocean temperature during typhoon passage: simulation with a 1-D turbulent model     

张连新  张学峰  韩桂军  吴新荣  崔晓健  邵彩霞  孙春健  张晓爽  王喜冬  付红丽 《中国海洋湖沼学报》2015,33(5):1164-1180

At the interface between the lower atmosphere and sea surface, sea spray might significantly influence air-sea heat fluxes and subsequently, modulate upper ocean temperature during a typhoon passage. The effects of sea spray were introduced into the parameterization of sea surface roughness in a 1-D turbulent model, to investigate the effects of sea spray on upper ocean temperature in the Kuroshio Extension area, for the cases of two real typhoons from 2006, Yagi and Soulik. Model output was compared with data from the Kuroshio Extension Observatory (KEO), and Reynolds and AMSRE satellite remote sensing sea surface temperatures. The results indicate drag coefficients that include the spray effect are closer to observations than those without, and that sea spray can enhance the heat fluxes (especially latent heat flux) considerably during a typhoon passage. Consequently, the model results with heat fluxes enhanced by sea spray simulate better the cooling process of the SST and upper-layer temperature profiles. Additionally, results from the simulation of the passage of typhoon Soulik (that passed KEO quickly), which included the sea spray effect, were better than for the simulated passage of typhoon Yagi (that crossed KEO slowly). These promising 1-D results could provide insight into the application of sea spray in general circulation models for typhoon studies.  相似文献