岩体分类实例分析与研究

通过岩体分类的大量实例 ,利用统计学和模型原理 ,探讨了RMR值、Q值和自稳时间各自所服从的分布规律 ,同时评价了它们与岩石类型之间和自身的相关关系 ,旨在通过实例及岩石类型的分析与研究 ,为以后工程实践及其理论研究起到一定的指导和帮助作用     

重庆主城区粉质黏土动力特性研究

采用自振（共振）柱和动三轴试验方法,得到重庆主城区粉质黏土动剪切模量和阻尼比随剪应变变化试验结果,比较分析试验值、文献[1]给出的推荐值和文献[2]给出的规范值的差异,并通过土层反应计算初步给出了这种差异对地表反应谱的影响,结果表明：(1) G/Gmax-γ关系中,规范值在中等应变时给出的G/Gmax比试验值和推荐值低;大应变时,相比较于试验值和推荐值,规范值衰减更快;(2) 相比较于λ-γ关系,G-γ关系经过Gmax归一化后,更具有一致性,粉质黏土阻尼离散性较大;(3) 试验值和推荐值计算的地表反应谱相差较小,但试验值和规范值计算的地表反应谱相差较大,特别是在随着输入地震动强度增大,这种差异性更显著。分析表明,重庆主城区进行土动力计算过程中,当无土动力特性试验资料时,选用规范值具有一定的局限性和风险,相比较于规范值,推荐值在一定程度上更具适用性。     

Q系统法在甘肃北山岩体质量评价中的应用研究——以BS03号孔为例

利用岩体质量评价Q系统的特点,对Q系统各参数进行赋值,根据Q值对BS03号孔附近岩体进行质量分级,给出定性结论。与利用RQD值所得岩体质量评价结果对比,一致性良好。     

砂体及其研究价值

本文论述了砂体的意义，砂体的研究价值，砂体的分类，并从多方面阐明了砂体在可地浸砂岩型铀矿找矿工作中的作用。抛砖引玉，力图推进砂体的研究工作，为可地浸砂岩型铀矿的找矿工作服务。     

第二松花江流域水电厂综合中长期水文预报的分析研究

基于对第二松花江流域上游小山、松山、两江水电站中长期水文预报研究成果，论述了综合中长期水文预报的研究思路和定性预报、定量预报的分析研究方法。该研究通过2002年实践检验，具有较高的预报精度。     

Natural background levels and threshold values of monitored parameters in the Cambrian-Vendian groundwater body,Estonia

The Cambrian-Vendian groundwater body plays an important role in drinking water supply of capital Tallinn and other settlements in northern Estonia. Water quality in this deep-seated confined groundwater body is influenced by the intrusion of present-day seawater and pumping-induced upward migration of deeper saline groundwater. The aim of this study is to evaluate the threshold values applying the methodology worked out within the EU 6th FP project “Background criteria for the identification of groundwater thresholds (BRIDGE)” and to compare the results with the values proposed by local authorities. A database containing 250 monitoring points was completed and used for the calculation of natural background levels (as the 90 and 97.7 percentile) in groundwater. The calculation of threshold values is based on natural background levels and reference values. In case of Cambrian-Vendian groundwater body the receptor is drinking water, thus limit values set by Estonian drinking water standard were used as reference values. The threshold values proposed by local authorities are more or less the same as calculated by BRIDGE methodology. Exceptionally different values are derived in case of chloride and ammonium.     

The HNCO ring in the Sgr B2 region

The large-scale structure associated with the 2′N HNCO peak in Sgr B2 [Minh, Y.C., Haikala, L., Hjalmarson, Å., Irvine, W.M., 1998. ApJ 498, 261 (Paper I)] has been investigated. A ring-like morphology of the HNCO emission has been found; this structure may be colliding with the Principal Cloud of Sgr B2. This “HNCO Ring” appears to be centered at (l,b) = (0.7°,−0.07°), with a radius of 5 pc and a total mass of 1.0 × 10⁵ to 1.6 × 10⁶ M. The expansion velocity of the Ring is estimated to be 30–40 km s⁻¹, which gives an expansion time scale of 1.5 × 10⁵ year. The morphology suggests that collision between the Ring and the Principal Cloud may be triggering the massive star formation in the Sgr B2 cloud sequentially, with the latest star formation taking place at the 2′N position. The chemistry related to HNCO is not certain yet, but if it forms mainly via reaction with the evaporated OCN⁻ from icy grain mantles, the observed enhancement of the HNCO abundance can be understood as resulting from shocks associated with the collision between the Principal Cloud and the expanding HNCO Ring.     

Comparison of ecophysiological characteristics between introduced and indigenous mangrove species in China

Due to its rapid growth, the introduced mangrove species Sonneratia apetala from Bangladesh has been widely used in mangrove restoration in southeastern China since 1985. As an indigenous mangrove species in Hainan, China, Sonneratia caseolaris was also planted in Guangdong Province for afforestation purposes. Both species have developed well in their new habitats, but their ecophysiological differences with the native mangrove species have not been studied. In this study, leaf gas exchange, water and nitrogen use efficiencies of two Sonneratia species were compared with those of selected native mangrove species (Avicennia marina, Aegiceras corniculatum, Kandelia candel, and Excoecaria agallocha) in Hainan and Shenzhen. The introduced S. apetala maintained lower carbon assimilation rate (A) and photosynthetic nitrogen use efficiency (PNUE) than the indigenous S. caseolaris. In Shenzhen, the two introduced Sonneratia had comparable photosynthetic rates and water use efficiency (WUE) with the native mangrove species, except that PNUE in S. caseolaris was significantly higher than in the native mangrove species. The two Sonneratia species showed significant overlap in PNUE and long-term WUE. Photosynthetic parameters derived from leaf photosynthetic light–response curves and A–C_i curves also suggested lower carbon assimilation capacities for the introduced Sonneratia than for the native mangrove species in both study sites. The lower light compensation point (LCP) of two introduced Sonneratia in both study sites also indicated a better adaptation to a low light regime than the native mangrove species. The results of photosynthetic capacities indicated that the introduced mangrove species have little competitive advantage over local native mangrove species in their respective new habitats.     

规则波作用下台阶地形上墩柱绕流三维数值研究

利用Flow-3D建立三维数值波浪水槽,模拟波浪在不对称台阶地形上的传播。系统研究规则波作用下墩柱周围水流的流动特性,分析墩柱周围的瞬时速度场、涡量场以及KC值变化,不同相位时墩柱前、后水平流速分布情况。结果表明:波浪在台阶地形传播的过程中,墩柱迎水面的涡动结构不够明显;高涡量呈对称状聚集在墩柱的背水面,并形成一对旋转方向相反的涡结构;周期对KC值的影响比波高的影响要明显;墩柱迎水面水平方向流速变化较大,侧面水平流速变化最为剧烈,背面由于受到墩柱的掩护作用水平方向流速变化不大,在墩柱的正面和侧面竖向环流明显。