Sorption of Ni on Na-rectorite studied by batch and spectroscopy methods

Sorption of Ni²⁺ on Na-rectorite as a function of contact time, temperature, pH and fulvic acid (FA)/humic acid (HA) was studied under ambient conditions. A pseudo-second-order rate equation was used to simulate the kinetic sorption. The removal of Ni²⁺ increased with increasing pH. The presence of FA/HA enhanced the sorption of Ni²⁺ at low pH values, whereas no drastic effect of FA/HA on Ni²⁺ uptake to rectorite was found at high pH values. The diffuse layer model (DLM) fitted the experimental data of Ni²⁺ sorption in the absence and presence of FA/HA very well with the aid of FITEQL 3.2. The Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models were used to simulate the sorption isotherms of Ni²⁺ at different temperatures. The thermodynamic data (ΔH⁰, ΔS⁰, ΔG⁰) were calculated from the temperature dependent sorption isotherms and the results suggested that the sorption process of Ni²⁺ on rectorite was spontaneous and endothermic. The sorption and species of Ni²⁺ on rectorite in the presence and absence of FA/HA was also investigated and characterized by XPS. The spectroscopic analysis indicated no drastic structural changes of Na-rectorite and the sorption of Ni²⁺ mainly occurred on the surface and at the edge position of Na-rectorite.     

Identification of sources and causes of leakage on a zoned earth dam in northern Taiwan: Hydrological and isotopic evidence

Seepage through an earth dam body must be regulated as a well–planned process, if it is not properly managed, the abnormal seepage may cause dam failure. This study employed stable isotopic and statistical methods to identify the source and cause of an abnormal leakage on the zoned earth dam of the Xin–Shan reservoir located in northern Taiwan. Water samples from the dam area over a 2-a period were collected and analyzed for their stable O and H isotope compositions. In addition, a 4-a period of hydrological data, including rainfall, reservoir level, well level, seepage of filter drainage and leakage, were statistically analyzed with a stepwise multiple regression approach. Both the stable isotopic and hydrological results indicate that the abnormal leakage on the dam shell comes from the filter drainage in the dam. The reason for abnormal leakage is due to unexpected and significant precipitation–sourced water flowing into the dam’s body. The dam filter fails to drain out the incoming water sufficiently, thus generating the abnormal seepage. In addition, the defect in the dam filter may also cause the drainage filter to drain off reservoir seepage inadequately. Therefore, it is suggested that checking the filter function and preventing excessive precipitation–sourced water from flowing into the dam are the two top priorities for the follow-up remedial strategy of the dam.     

Biogeochemical characteristics of the Hetai goldfield, Guangdong Province, China

In the Hetai goldfield, Guangdong Province, China, samples including rocks, soils and leaves of four plants (Pinus massoniana, Rhodomyrms tomenlosa, D. linearis var. dichotoma and Embelia laeta) collected from the gold mineralization zone and the background area were analyzed for Au, Ag, Cu, Pb, Zn, Hg, As and physiological parameters. The objective of this investigation is to study the geochemical and biogeochemical characteristics of studied plants, aiming at biogeochemical methods in Au exploration. The goldfield region shows geochemical and biogeochemical anomalies. Abundances of Au in rocks, soils, plants and the leaf pigments in the mineralized area are much higher than those in the surrounding region. The plants display unhealthy physiological and ecological characteristics in the Hetai goldfield area. The cell structures of the goldfield plants were anomalous and aberrant, and there were many nano-metal particles diffused in mitochondria and chloroplasts. Macro- and microscopic evidences of the vegetation in the goldfield areas are distinctly different from the background regions. The strongly anomalies in responses to Au are profound in further geochemical and botanic exploration studies.     

渤海湾盆地新生界生油岩系底界面温度分布

依据渤海湾盆地2000余口测温井的地温梯度数据、地层岩性描述、分层数据以及钻井资料,计算了该盆地各生油岩系底界面的温度。统计结果表明:渤海湾盆地沙河街组大部分凹陷区地层底界面温度介于90℃至150℃,目前仍具有大量生油的温度条件,而在隆起或一些凸起地区,该地层组段温度普遍小于90℃,未能达到生油的温度指标。东营组和孔店组地层也仍具有一定的生油温度条件。研究还表明:地层温度与地层界面埋深密切相关,温度随界面埋深的增大而升高,沉积厚度大的凹陷区地层界面温度大于沉积厚度小的凸起区或斜坡地带,说明地层界面埋深是决定地温高低的主要控制因素,而地温梯度对地层界面温度的影响相对较小。     

滑坡体三维地质建模与可视化分析

针对滑坡地质研究的自身特点,提出了面向滑坡地质体三维建模的NURBS-BRep混合数据结构和地质结构单元实体构造技术.通过对滑坡基础地质数据的预处理、滑坡数字地形和滑动面的三维建模、地质结构面的系统构造、地质结构体的生成和显示,形成了一套完整的滑坡三维地质模型的构建方法.将该方法应用于某水库滑坡,建立了相应的三维滑坡地质模型,并基于此模型进行了三维剖切分析、数字钻孔、等值线生成、滑块自动剖分、滑坡失稳可视化动态模拟和滑坡体方量精确计算等一系列实用的可视化分析,为滑坡稳定性的准确计算和客观评价提供了有力的支持.     

舟山国家石油储备基地堆载预压加固效果分析

介绍了舟山国家石油储备基地试验区软基堆载预压大型现场试验结果,根据现场试验测得的数据,分析了软土地基堆载预压下沉降变化规律、分层沉降变化规律、深层土体位移变化规律、超静孔隙水压力变化规律,进一步探讨了根据应力和应变分析得到的地基固结性状,其中通过应变分析得到适用于储备基地的沉降经验系数m。结果表明,打设塑料排水板结合堆载预压处理软弱地基具有良好的效果。     

Copula函数在多变量水文分析计算中的应用及研究进展

综述了多变量水文分析计算方法及存在的问题.系统地介绍了Copula函数的基本理论与方法,分析探讨Copula函数在多变量水文计算领域的适用性及优越性.总结了Copula函数应用的关键技术,包括参数估计、拟合检验及类型选择等,并展望了Copula函数的研究应用前景.     

浙江省小流域山洪灾害临界雨量确定方法分析

小流域山洪灾害具有突发性,预测预警难度较大.本文结合浙江省小流域山洪灾害防御的实践经验,研究提出了以水位反推法计算临界雨量,简单实用,具有较好的实践价值和推广意义.     

海拉尔盆地贝西斜坡北部地区储层特征及影响因素分析

通过测井曲线的标准化处理及信息提取、岩心及录井岩屑观察、铸体薄片、物性分析、扫描电镜、压汞分析等技术手段,研究了海拉尔盆地贝西斜坡北部地区南屯组储层的主要岩性特征、物性特征、储集空间类型和影响因素.研究结果表明.海拉尔盆地南屯组以内陆湖相碎屑岩为主,主要包括角砾岩、砾岩、砂砾岩、粗砂岩、细砂岩、粉砂岩、泥质砂岩及泥岩等.南一段储层孔隙度平均值为6.15%,渗透率平均值为0.31 × 10-3μm2,为低孔特低渗型孔隙特征;南二段储层孔隙度平均值为12.18%,渗透率平均值为2.79× 10-3μm2,属于中孔低渗型孔隙特征.储集空间类型以粒间孔隙为主,发育一定的次生孔隙.喉道分为4种类型(Ⅰ类、Ⅱ类、Ⅲ类、Ⅳ类).扇三角洲前缘分支水道砂体、扇三角洲平原辫状河道砂体和滨浅湖砂坝微相砂体为该区有利的储层砂体类型.储层性质主要受沉积相和成岩作用影响.     

南印度洋SST与南亚季风环流年代际变化的研究

利用美国NCEP全球大气再分析资料和JONES全球海表面温度异常(SSTA)资料，分析了南印度洋SSTA和南亚季风环流年代际变化的特征。研究发现，无论是南印度洋副热带海水辐合区的SST还是赤道以北非洲西海岸附近上升运动海区的SST的长期变化趋势，除了准3-5年的变化以外，还存在着明显的年代际的变化。对于全球最显著南亚季风环流的分析表明，南亚季风环流也存在明显的年代际时间尺度的变化。与南太平洋SST的年代际变化相比，南印度洋SST的变化周期要相对短一些。通过分析南半球冷空气年代际活动的特征发现，冷空气与南印度洋SST年代际时间尺度的变化具有密切的联系。