Highway flood disaster risk evaluation and management in China

Flood disaster has become one of the most damaging natural disasters for the highway transportation all around the world, especially its destructive effects on highway infrastructures. In order to better understand the ruinous influence of flood disaster on highway transportation in China, this paper proposes an alternative evaluation index of highway flood disaster risk from three aspects, namely the disaster-causing factors, disaster-inducing environment, and disaster-bearing subjects. This paper also puts forward some targeted suggestions for the risk management, including two aspects: physical protection measurement and organization and management measurement. Moreover, this paper develops a highway flood disaster risk management system by using the ArcGIS technology.

     

郴州水湖里矿区水文地质条件在补勘中的重新认识

通过矿区补充地质勘探的水文地质工作和现有生产坑道的揭露，对水湖里矿区水文地质条件有新的认识，重新预算了矿坑涌水量。     

Soil bio-cementation using a new one-phase low-pH injection method

Acta Geotechnica - Soil bio-cementation via microbially induced carbonate precipitation (MICP) has been extensively studied as a promising alternative technique to traditional chemical cementing...     

Dissolved constituents and Sr isotopes in river waters from a mountainous island – The Danshuei drainage system in northern Taiwan

Taiwan is a typical active orogenic belt situated at the collision boundary between the Eurasian Continental Plate and the Philippine Sea Plate. Dissolved major and trace constituents, as well as Sr and Sr isotopes in river waters collected from the Danshuei River basin in northern Taiwan have been studied to evaluate chemical weathering processes. The results of principal component analysis show that the ion sources in these river waters can be categorized into 3 major components: chemical weathering, seasalt contribution and local anthropogenic input. The chemical weathering is the most dominant factor that contributes about 85% of total variances. Significantly increased Na/Cl and Ca/Cl, as well ⁸⁷Sr/⁸⁶Sr, were observed in most upper stream samples. The Na/Cl and Ca/Cl ratios in the Dahan Stream, however, are much higher than the Shindien Stream. Even though average rainfall is stronger in the Shindien drainage basin, chemical evidence from river waters supports less intense weathering in the region. Selective dissolution of secondary calcites explains the observed high Ca/Cl, Sr/Cl and Ca/Na in the Dahan Stream. These results highlight the potential importance of tectonic factors, such as uplift and physical erosion in studying chemical weathering in an active orogenic belt.     

基于能量定义的边坡临界滑动场方法

边坡临界滑动场法是最近发展起来的边坡稳定性计算方法,通过定义外力功与内能耗散之差为剩余功。基于能量定义的边坡临界滑动场模拟的主要思路为：给定一个安全系数,寻找最大剩余功对应的滑动面,变换安全系数直到所得最大剩余功为零,其对应的滑动面即为临界滑动面,相应的安全系数即为最小安全系数。通过两个典型土坡算例分析证明了该方法的有效性,与传统的临界滑动场相比,该新方法不再需要条间力假定,计算简单。     

基于相似系数的1种算法在遥感图像分类中的应用

用基于向量夹角余弦的相似系数方法对黄河三角洲 1 998年 1 2月份的 Landsat- 5TM遥感影像进行了分类 ,分类精度分析表明用夹角余弦作为分类的相似性度量指标是合理的。这种遥感图像的分类方法简单 ,在实际分类中可以作为常用的方法之一。     

The effect of PCBs on glycogen reserves in the eastern oyster Crassostrea virginica

Recent declines in Chesapeake Bay oyster populations have been attributed to disease, and reduced water quality from pollution. The stress associated with pollutant exposure may reduce energy available for growth and reproduction. Polychlorinated biphenyls (PCBs) are lipophilic contaminants that may potentially affect mobilization of lipid reserves, increasing reliance on glycogen stores, which could otherwise be utilized to supply energy for gametogenesis. Thus, PCBs may indirectly affect glycogen stores in oysters in a deleterious manner. To test for this effect, reproductively inactive oysters were exposed to PCBs by feeding individuals 0.7 g of algal paste containing 0, 0.35, or 3.5 μg PCBs daily for 8 weeks. Additionally, a group of oysters was exposed to PCBs (0, 0.35, and 3.5 μg) plus 0.3 g of non-toxic artificial sediment to examine interactive effects of sediment particles and PCBs. Adductor muscle, mantle, and gonadal tissues were analyzed for glycogen content. Results suggest that glycogen content is reduced in the adductor muscle with increasing PCB exposure, but there are no effects of PCBs in the mantle and gonadal tissues.     

黄河流域泥沙时序混沌特征——地理学综合研究的一种尝试

The sediment content of the Yellow River is resulted from the interactions of natural, economic,and social factors,so it includes some evolutive information of the Yellow River Basin system.Sediment contents from 1952 to 2007 on Toudaoguai,Tongguan,Huayuankou and Lijin sections along the river are chosen as the study time series,and correlation dimensions(D2),Kolmogorov entropies(K2),and Hurst indexes(H)of the time series were calculated.Correlation dimensions on Toudaoguai,Tongguan,Huayuankou,and Lijin sec...