Screening model for volatile pollutants in dual porosity soils

This paper develops mass fraction models for transport and fate of agricultural pollutants in structured two-region soils. Mass fraction index models, based on a semi-infinite domain solution, are derived that describe leaching at depth, vapor losses through soil surface, absorption, and degradation in the dynamic- and stagnant-water soil regions. The models predict that leaching is the result of the combined effect of the upward vapor-phase transport relative to downward advection, residence time relative to half-life, dispersion, and lateral diffusive mass transfer. Simulations show that leached fraction of volatile compounds does not always decrease monotonically with increased residence time relative to the pollutant half-life, as a result of complex interactions among the different physical and biochemical processes. The results show that leaching, volatilization, and degradation losses can be affected significantly by lateral diffusive mass transfer into immobile-water regions and advection relative to dispersion (i.e. Peclet number) in the mobile-water regions. It is shown that solute diffusion into the immobile phase and subsequent biochemical decay reduces leaching and vapor losses through soil surface. Potential use of the modified leaching index for the screening of selected pesticides is illustrated for different soil textures and infiltration rates. The analysis may be useful to the management of pesticides and the design of landfills.     

海洋平台结构振动的AMD主动控制参数优化分析

本文针对海洋平台结构的冰激振动和地震反应控制问题，提出了采用AMD主动控制的控制策略，结合JZ20－2MUQ平台结构进行了AMD控制系统的硬参数和软参数的优化分析，并就相应于最优参数下的AMD控制海洋平台结构冰激振动和地震反应的几种代表性工况进行了时程分析，得到了一些定性和定量的结论，为实际工程的控制设计提供了基础。本文提出的AMD主动控制方法对类似的海洋平台结构的控制问题也有参考价值。     

2001年11月14日新疆-青海交界8.1级地震

简要介绍了2001年11月14日新疆－青海交界8．1级地震的预测情况，给出了中、美、日等对此次地震的震源参数测定和震源机制，以及余震的分布和加卸载响应比随时间的变化。进而对震区近期地震趋势进行预测。     

Fire Severity,Water Repellency Characteristics and Hydrogeomorphological Changes Following the Christmas 2001 Sydney Forest Fires

Soil water repellency can enhance overland flow and erosion and may be altered by fire. The Christmas 2001 bushfires near Sydney allowed investigation of the relationship between fire severity, water repellency and hydrogeomorphological changes. For two sub-catchments with differences in fire severities in Nattai National Park, south-west of Sydney, this paper considers: (1) the links between fire severity based on SPOT image analysis and ground observation of fire severity and repellency; (2) the textural and organic/minerogenic characteristics of eroded sediment; and (3) erodibility, erosion and deposition of soils in both catchments. Ground surveys show that image analysis reflects well the degree of vegetation consumption by fire, but cannot adequately predict the degree of ground litter consumption, associated soil heating and repellency effects. Fire had varying effects on repellency, leaving it unchanged, destroying it or enhancing it, depending on the soil temperature reached. The main post-fire hydrogeomorphological changes have been widespread erosion and colluvial and alluvial deposition of topsoil in foot-slope locations and river systems, but only localised redistribution of the highly erodible, repellent sandy subsurface layer. The fire did not trigger major geomorphological change in the study area, but fires probably cause important topsoil and nutrient depletion and may also affect water quality.     

陇东地区水土流失与地质作用初步分析

陇东地区是黄河上游水土流失严重区 ,也是国家重点治理的地区之一。由于特殊的岩土体的存在 ,加重了这一地区水土流失作用的危害性。本文通过水土流失现象与地质作用的关系进行偿试性探讨 ,旨在从中找到防治水土流失的有效措施 ,开展治理工作     

中国大陆科学钻探钻探子工程钻进实时记录网页的开发

以中国大陆科学钻探实时记录网页的开发为例，介绍了在开发网络数据库时，利用Excel组件作输入界面，实现查询界面上表格的表头和表尾不动、而中间行可以滚动，实现回次滚动查询和界面实时刷新。     

应用航放资料寻找非放射性金属矿产效果探讨

本通过对粤北地区已知的52个非放射性金属矿床（点）的地质、物化探特征的统计资料综合分析，建立了评价非放射性金属矿产成矿远景的航空能谱参数模型，结合重磁测量、重砂测量及金属量测量成果，预测了4片非放射性金属矿产成矿远景区。     

云南省癌死亡率与土壤环境中化学元素的关系

癌病严重危害人类生命。研究表明：土壤环境中微量元素与肿病发生发展以及治疗相关，个别地区的地方病与元素含量关系密切。对土壤中元素含量研究证实：云南癌死亡率低于全国平均水平。文章详细讨论云南9种频发、52种常见癌症与元素的关系。     

总磷作为饮用水生物稳定性控制指标的研究

根据国内提出的控制饮用水生物稳定性的可同化有机碳(AOC)标准,通过配制水样研究了AOC及细菌再生长潜力(BRP)同水中磷含量的关系;同时针对净水工艺试验出水水样,考察了水中的磷同其生物稳定性的关系。结果表明,对于配水水样,在一定的磷浓度范围内,磷是水中细菌生长的限制因子;在净水试验工艺出水水样中添加50μg/L的PO₄3--P后,AOC增加了55%,BRP增加了123%,表明水中磷是其生物稳定性的限制因子。由于常规的净水工艺对水中的磷可以有效去除,把水中总磷(TP)控制在5μg/L内来提高饮用水生物稳定性具有一定的可能性和现实性。     

油气化探综合异常模糊划分动态聚类分级评价

通过选取描述油气化探综合异常的各种特征参量，借助模糊数学工具，利用最优聚类中心所具有的代表特征，建立分级指标，对油气化探综合进行分级评价。鄂尔多斯盆地油气化探综合异常的评价实例结果表明，利用油气化探综合异常各种特征参量进行动态聚类分级评价是可行的。