Chevron Ridges and Runup Deposits in the Bahamas from Storms Late in Oxygen-Isotope Substage 5e

Landward-pointing V-shaped sand ridges several kilometers long are common along the windward margin of the Bahama Islands. Their axes share a northeast–southwest trend. Internally, the ridges contain low-angle oolitic beds with few erosional truncations. Commonly interbedded are tabular, fenestrae-rich beds such as those formed by the sheet flow of water over dry sand. Defined here as “chevron ridges,” these landforms appear to have originated in the rapid remobilization of bank margin ooid bodies by the action of long-period waves from a northeasterly source. Deposits along adjacent coastlines also preserve evidence of the impact of large waves. Reworked eolian sand bodies preserve beach fenestrae and hydraulic scour traces up to +40 m on older ridges. On cliffed coasts, 1000-ton boulders have been thrown well inland, recording the impact of large waves. Amino acid ratios confirm a correlation of the ridges across the archipelago, while stratigraphy, spacing, and cross-cutting relationships indicate emplacement as sea level fell rapidly from the substage 5e maximum at or above +6 m.     

高放废物处置库预选场地地学信息库的建立

本文以高放废物处置库预选场地甘肃北山玉门镇地学信息库的建立为例,详细阐述了地理信息系统在高放废物地质处置中的应用,并在此基础上分析了其应用前景,为不同层次的管理、科研人员提供了全新思路;介绍了将地理信息系统技术引入图件和资料管理的优点。     

作物生长岩-土环境中不同存在形态钾素含量动态变化

以较系统的观测资料,对土壤环境中的缓效态、速效态、水溶态钾素含量的动态变化进行探索.结果表明,缓效态钾的季节性动态变化制约着速效态、水溶态钾的季节性动态变化,但是后两者变化幅度较缓效态钾的大;这种动态变化同时受土壤类型和深度的影响.     

CT技术在土体结构性分析中的应用初探

提出了一种利用 Ｃ Ｔ 技术定量评价黄土结构性的方法。利用该方法对不同压实度的黄土进行了初始扫描,并从 Ｃ Ｔ 数和 Ｃ Ｔ 图像两方面分析压实黄土的初始结构,得到一些有益的结果。     

冻土力学发展的新领域——深土冻土力学

Based on the practice of artificial freezing engineering in deep alluvium and simulation tests, it is found that there exists an obvious difference between frozen soil mechanics for shallow alluvium and for deep alluvium. The concept of frozen soil mechanics for deep alluvium, its research topics and methods are presented in this paper.     

A Winkler model approach for vertically and laterally loaded piles in nonhomogeneous soil

An investigation is made to present analytical solutions provided by a Winkler model approach for the analysis of single piles and pile groups subjected to vertical and lateral loads in nonhomogeneous soils. The load transfer parameter of a single pile in nonhomogeneous soils is derived from the displacement influence factor obtained from Mindlin's solution for an elastic continuum analysis, without using the conventional form of the load transfer parameter adopting the maximum radius of the influence of the pile proposed by Randolph and Wroth. The modulus of the subgrade reaction along the pile in nonhomogeneous soils is expressed by using the displacement influence factor related to Mindlin's equation for an elastic continuum analysis to combine the elastic continuum approach with the subgrade reaction approach. The relationship between settlement and vertical load for a single pile in nonhomogeneous soils is obtained by using the recurrence equation for each layer. Using the modulus of the subgrade reaction represented by the displacement influence factor related to Mindlin's solution for the lateral load, the relationship between horizontal displacement, rotation, moment, and shear force for a single pile subjected to lateral loads in nonhomogeneous soils is available in the form of the recurrence equation. The comparison of the results calculated by the present method for single piles and pile groups in nonhomogeneous soils has shown good agreement with those obtained from the more rigorous finite element and boundary element methods. It is found that the present procedure gives a good prediction on the behavior of piles in nonhomogeneous soils. Copyright © 2011 John Wiley & Sons, Ltd.     

济南泉域地下水位动态及其对降水响应的交叉小波分析

利用1988—2009年济南泉域8个地下水位动态观测点不同时段观测资料及1998—2009年降水数据,采用连续小波变换、交叉小波变换方法对济南泉域地下水位动态的多时间尺度特征、相互关系及其对降水的响应进行了分析。结果表明:①济南泉域地下水位动态存在显著的0.82～1.16 a的主振荡周期,低频部分仅在部分年份存在1.95～3.09 a的振荡周期;②含水岩组富水性对地下水位动态存在影响,研究区主径流方向上弱富水性地段地下水位动态时滞较强富水性地段长,强富水性地段4个观测孔地下水位波动时序基本一致;③地下水位动态对降水的响应滞后明显,为73.06～134.42 d,总体表现为地下水径流路径越长,响应越滞后;④基于地下水位动态与基于降水—地下水位动态交叉小波变换得到的观测点对水位动态的滞后时间多数一致,同一径流路径上局部点对滞后时间之和与全局点对有很好的对应关系。交叉小波分析可定量评价泉域地下水位动态及其与降水的相关关系。     

内蒙古自治区土壤有机碳库储量及分布特征

根据内蒙古自治区土壤资料中共461个土壤剖面数据估算表层及全剖面的土壤有机碳密度(SOCD)和储量(SOCR),绘制其SOCD的空间分布图,并对其影响因素进行了探讨。结果表明:内蒙古地区的表层SOCD为0.63～15.93 kg.m-2,平均为3.68 kg.m-2;全剖面SOCD为0.22～68.77 kg.m-2,平均为10.35 kg.m-2,不同土壤类型之间有一定差异。内蒙古表层SOCR为4.10 Pg,而全剖面储量为10.79 Pg。土壤有机碳含量及分布受气候、土壤性质和人为活动的影响明显。最后,根据年均温与土壤有机碳密度的相关关系,估算得出当气温升高1℃,内蒙古地区土壤有机碳的释放量为0.91 Pg。     

新型城镇化测评指标体系的建立研究

城镇化是当今世界上重要的社会、经济现象之一。通过对国内外城镇化水平测度方法的回顾,分析目前国内外城镇化水平测度存在的问题。结合当前国家提出的新型城镇化发展战略,探讨了新型城镇化的内涵,从发展理念、发展目标、推动主体、推进机制和推进策略五个方面对传统城镇化和新型城镇化进行了对比。最后,提出新型城镇化测评的指标体系。     

成矿能在吉林四平钨矿土壤测量工作中的应用效果分析

利用传统的土壤测量方法,发现了四平市脉状蚀变破碎带型白钨矿矿床。土壤异常具有强度高、套合好的特点。试用Н.И.萨弗罗诺夫提出的成矿能理论,进行成矿元素地球化学分析及化探综合异常提取研究来表达土壤测量异常,结果表明,该方法具有概括性好,地质效果更加明显的优点。