西藏“一江两河”中部流域地区土地沙漠化防治目标,对策与治沙工程布局

西藏“一江两河”中部流域地区是我国沙漠化强烈发展的地区之一。根据“一江两河”综合开发部署和沙漠化的实际状况，制定了本区沙漠化防治的目标、对策和治沙工程布局。“八·五”、“九·五”期间治理沙漠化土地８．４６万ｈａ。治沙工程实施后，综合效益指数将比１９９０年提高３３．７％，系统功能状况与效益水平在整体上提高１／３。     

Winds and sand movements in the Namib Sand Sea

Wind regimes in the vicinity of the Namib Sand Sea are high energy unimodal near the coast, becoming bimodal or complex inland. There is an overall decrease in wind energy and sand transport rates from south to north and west to east, such that sand moves from coastal and southern source areas to accumulate in the northern and central parts of the sand sea. Such a pattern can explain much of the observed spatial variability in dune types, sizes, and sediment characteristics and lends support to a climatic model of sand sea formation in this region. Seasonal and daily cycles of wind velocity and direction give rise to episodic sand transport, most of which is generated by winds of moderate velocity and frequency.     

考虑地基土液化影响的桩基高层建筑体系地震反应分析

本文建立了土体－结构体系地震反应分析的混合有限元法，并研究了地基土液化对地震反应的影响。本方法把土体－结构体系简化为一个完整的体系，该体系由梁（柱）单元、剪切杆单元、刚体单元、平面四边形等参单元与三角形单元、界面单元的任意组合来模拟。桩与上部结构材料视为线弹性体，土介质视为非线性材料。土的静应力－应变关系之间的非线性用邓肯一张模型来描述；土的动应力－应变关系之间的非线性和振动孔隙水压力对土的软化效     

武汉市轨道交通二号线工程场地砂土液化分析

本文详细介绍了武汉市轨道交通二号线工程场地地震地质灾害评价中对饱和砂土液化的分析方法及评价结果。     

科尔沁沙地30种植物叶凋落物CO2释放量及释放速率的研究

 采用可以有效控制环境因子的室内土壤培养试验，初步研究了科尔沁沙地30种植物叶凋落物的CO₂释放量及释放速率。结果表明：①在28 d培养期内，不同植物叶凋落物释放的CO₂量差异很大，其中，多年生植物叶凋落物CO₂释放量平均值大于一年生植物，但二者之间的差异不显著；禾本科植物叶凋落物CO₂释放量平均值明显小于其他植物，二者之间呈显著差异。②在28 d培养期内，不同植物叶凋落物每四天CO₂释放速率差异很大。一年生与多年生植物叶凋落物28 d内每四天释放CO₂的速率无显著差异；禾本科与其他植物叶凋落物每四天释放CO₂的速率在培养的前16 d差异呈显著，而后差异消失。③植物叶凋落物的全碳含量，氮含量，C／N，灰分/N及灰分含量不同造成CO₂释放量及释放速率的差异。叶凋落物28 d释放CO₂的量与叶凋落物初始碳含量及灰分含量均无相关关系，与叶凋落物初始氮含量呈显著正相关，与叶凋落物C／N及灰分／N呈显著负相关。叶凋落物培养期内每四天释放CO₂的速率与叶凋落物初始碳含量无相关关系；叶凋落物0\_20天释放CO₂的速率与叶凋落物初始氮含量呈显著正相关，与叶凋落物C／N呈显著负相关；叶凋落物9\_28天CO₂释放速率与灰分／N呈显著负相关；培养后期（17\_28天）的CO₂释放速率与灰分含量呈显著负相关。     

四川紫色雏形土的蒸发性及其与土壤结构性的关系

结合四川土壤基层分类 ,选取四川紫色雏形土的几个土系 ,对土壤的水分发性能及其与土壤结构性尤其是机械组成和微团聚体组成的相关关系分析发展 ,土壤水分蒸发具有明显的阶段性 ;土壤水分累积蒸发量与蒸发历时之间总体上符合乘幂方程 ;土壤蒸发速度与〈0 .0 0 1mm的颗粒含量呈明显相关关系 ,与 >0 .2 5mm的大团聚体含量呈明显负相关关系。     

疏松砂岩稠油油藏出砂冷采机理及配套技术研究

稠油出砂冷采技术对地层原油含有溶解气的各类疏松砂岩稠油油藏具有较广泛的适应性，它通过大量砂子的产出和泡沫油的形成，获得较高的原油产量，河南油田于1996年在国内率先开展稠油出砂冷采技术调研及可行性研究，出砂冷采机理及配套工艺技术研究，并于1997年6月进入现场先导试验，矿场试验已展示出明显出砂冷采特征的G4906井，日产油量20t-30t，是常规开采和蒸汽吞吐的10倍和4倍以上，开采成本比蒸汽吞吐降低47%，出砂冷采工业化应用配套技术的形成和应用，将使国内及河南油田稠油资源利用程度进一步提高。     

Evaluation of density in layer compaction using SASW method

SASW test, which is non-intrusive and rapid in the field application, was used to evaluate the layer density in the roller compaction without performing the complicated inversion process. The concept of normalized shear wave velocity was introduced to minimize the effect of confinement in the density evaluation. SASW test was performed to determine the shear wave velocity of the layer, and the free–free resonant column (FF–RC) test was adopted to determine the correlation between the normalized shear wave velocity and density of the site, which is almost unique independent of confinement. Testing and data reduction procedures of both tests were briefly discussed and an evaluation procedure of the field density was proposed by effectively combining in-situ shear wave velocity determined by the SASW test with the correlation between the normalized shear wave velocity and the density determined by the FF–RC test. Finally, the feasibility of the proposed method was verified by performing a field case study at Hoengsung road construction site. Field densities determined by the proposed method matched well with those determined by sand cone tests, showing the potential of applying the proposed method in the field density evaluation.     

三峡库区紫色土坡地养分状况及养分流失*

紫色土是三峡库区移民安置区的主要坡地土壤。本研究采用典型区域调查,代表性土壤剖面养分分析,结合实验小区人工降雨的方法,初步研究了发育于侏罗纪紫色砂泥岩母质上紫色土的养分状况、养分流失特点、过程及影响养分流失因素。