我国天然钠质膨润土

膨润土又称膨土岩或斑脱岩,是以蒙脱石类矿物为主要成分的粘土岩,是一种含水的铝硅酸盐矿物。 蒙脱石颗粒极细,由于晶格置换晶层表面带有大量负电荷,能吸附可交换性阳离子。以吸附钠离子为主时称为钠质膨润土,以吸附钙离子为主时称为钙质膨润土。此外,还有过渡类型。钠质膨润土具有高的电动电位和极强的水化能,在物性上优于钙质膨润土,从而有广泛应用价值。在冶金工业中用于球团矿的粘合剂。     

离子交换法处理含砷废水的小试/中试试验

利用选择性复合树脂处理含砷废水,使出水水质达到国家《地表水环境质量标准》(GB 3838 2002),同时从选择性复合树脂和阳离子柱上交换下来的离子可以生成H2O和中性盐类,无二次污染.研究采用201×7苯乙烯系强碱凝胶型树脂(Ⅰ)和D301大孔弱碱阴离子交换树脂(Ⅱ)作为比选树脂,通过小试试验选择具有较高交换容量的201×7苯乙烯系强碱凝胶型树脂用于放大规模的现场中试.实验所用选择性复合树脂制作成本及整个中试系统价格低廉,适合大规模工厂应用.     

云南杞麓湖沉积物记录的近现代生态环境变化及影响因子识别

随着云南社会经济的持续发展与极端气候事件的频发,高原大中型湖泊面临着水质恶化、生态与环境功能退化的长期胁迫.为识别亚热带大型湖泊面临的主要环境压力,以杞麓湖为研究对象,在对沉积物钻孔进行物理(粒度、烧失量)、生物(色素、硅藻)等指标分析的基础上,结合现代监测和湖泊调查数据,重建了近两百年来湖泊水文条件、富营养化和环境变化的历史,并对硅藻群落结构的演化进行了驱动过程识别.沉积物粒度在1958年之前变化总体较为稳定且有较高的黏土含量;随着围湖造田等流域开发的增强,沉积物粒度组成自1960s开始频繁波动且粗颗粒组分快速增加.1981—2000年期间,随着落水洞泄水工程的修建杞麓湖的水位控制与水文调控得到加强,沉积物砂质含量降低且粒度组成变化较小;2000—2013年期间,湖泊疏浚工程的开展和区域降水的持续减少都导致了沉积物粒度组成波动较大、粗颗粒组成较高.沉积物色素记录了湖泊初级生产力的缓慢上升出现于19世纪中后期,并自1960s开始总叶绿素与蓝藻色素含量总体出现了较大幅度的增加趋势并持续至今.而在2000—2005年期间,湖泊浅水区的疏浚清淤导致了内源营养盐输入量的降低与藻类生物量的明显下降;沉积物蓝藻色素含量在1998、2008和2012—2013年左右出现明显的峰值,指示杞麓湖可能出现了较大范围的蓝藻暴发事件.统计分析结果显示,湖泊硅藻群落结构出现了多次明显转变且呈现底栖硅藻百分比长期降低的特征,水体富营养化的持续是驱动硅藻群落结构演替的主要因子,而水生植物退化、水文条件与气候变化也对硅藻群落的构建产生了重要的叠加影响.本文的沉积物分析结果表明,亚热带大型湖泊的生态治理与环境保护需要重点围绕营养盐负荷控制、水文调控优化与底栖生境恢复,并需应对全球变暖与极端气候事件产生的叠加影响.     

自动站数据质量控制中关联规则挖掘的应用

为进一步提高自动气象站数据的业务可用性,提出了基于关联规则挖掘技术的自动气象站数据质量控制算法,以相对湿度与风向、风速观测要素变化间的关联关系为例,总结了自动气象站相关观测项目间可能存在的关联规则,进而指导建立适合不同地域、不同气候特征的专家知识规则库,用以完善自动气象站数据质量控制系统,为天气预报和气象服务提供更加精准的气象观测数据。文章还对关联规则专家知识库的可靠性进行了验证,具备了一定的实用价值。     

Paleomagnetic results of Paleozoic and Mesozoic rocks from Xingshan-Zigui section in Hubei Province, South China

The paleomagnetic reconnaissance study of the Paleozoic and Mesozoic sedimentary rocks from the Yangtze Block (YZB) was made to conduct the Apparent Polar Wander Path (APWP) of the YZB during the Phanerozoic. A total of 825 samples from 84 sites were collected from a continuous section along the Xiangxi River valley in Xingshan and Zigui counties in Hubei Province, northern margin of the YZB. Stepwise thermal/alternating demagnetization isolated well defined characteristic magnetization (ChRM) at a higher temperature in most of the samples, and relatively thermal stability and high coercivity were revealed from these samples. All the ChRMs can pass the fold and/or reversal tests, suggesting that they are probably primary. Therefore, new pole positions are presented for the YZB. Project supported by the National Natural Science Foundation of China (Grant No. 49334050).     

唐山7.8级地震前水氡异常演化特征

根据华北地区分布的３３个水化观测点的水氡观测资料,以半年为尺度对唐山７．８级地震前水氡的异常演化过程进行了研究,认为：唐山７．８级地震前水氡异常存在由外围向震中区演化的异常特征,且在唐山地震发生的短临阶段,水氡异常在唐山地区形成集中,异常强度最大。     

危机黄金矿山增储的主要评价途径

通过研究实例较系统地讨论了危机矿山增储的主要评价途径 ,在充分分析区域成矿地质背景的基础上 ,以成矿地质条件为依据 ,突破旧观念 ,对控矿因素进行优势分析 ,设计一套科学的评价途径 ,是危机黄金矿山增储评价不可缺少的几个环节。     

从断层相互作用研究华北地区未来的地震危险性

从应力释放角度研究断层相互作用,采用合应力描述已发震断层对相邻活断层稳定性的影响。研究认为,合应力为正的地区,未来发震的可能性增大;反之,发震的可能性减小。对华北地区１９６６～１９７７年发生的１４次６级以上地震进行了预测效能检验,结果表明,合应力为正值的地区与后继强震的相关达７５％。将研究结果应用于华北地区,给出了该地区２００５年前可能发生强震的危险区,为中长期地震预报提供依据。     

Review: Groundwater management and groundwater/surface-water interaction in the context of South African water policy

Groundwater/surface-water interaction is receiving increasing focus in Africa due to its importance to ecologic systems and sustainability. In South Africa??s 1998 National Water Act (NWA), water-use licenses, including groundwater, are granted only after defining the Reserve, the amount of water needed to supply basic human needs and preserve some ecological integrity. Accurate quantification of groundwater contributions to ecosystems for successful implementation of the NWA proves challenging; many of South Africa??s aquifers are in heterogeneous and anisotropic fractured-rock settings. This paper reviews the current conceptualizations and investigative approaches regarding groundwater/surface-water interactions in the context of South African policies. Some selected pitfall experiences are emphasized. The most common approach in South Africa is estimation of average annual fluxes at the scale of fourth-order catchments (??500 km²) with baseflow separation techniques and then subtracting the groundwater discharge rate from the recharge rate. This approach might be a good start, but it ignores spatial and temporal variability, potentially missing local impacts associated with production-well placement. As South Africa??s NWA has already been emulated in many countries including Zambia, Zimbabwe and Kenya, the successes and failures of the South African experience dealing with the groundwater/surface-water interaction will be analyzed to guide future policy directions.     

Spatio-temporal variation of groundwater recharge in response to variability in precipitation, land use and soil in Yanqing Basin, Beijing, China

It is important to understand how groundwater recharge responds to precipitation variability in space and time, especially in those areas such as Yanqing Basin (China), where groundwater represents the sole water resource. A simple soil-water balance method is applied for spatio-temporal simulation of groundwater recharge in Yanqing Basin from 1981 to 2000. It was implemented on a monthly time step considering the effects of land use and soil texture. The area-average recharge associated with various land uses and soil textures was then compared with zonal analysis using a geographic information system (GIS). The main findings include: (1) the variation of groundwater recharge follows precipitation changes, either at yearly or seasonal intervals, (2) land use plays a more influential role in groundwater recharge than soil texture in this area, and (3) the water table quickly rises in response to recharge in the shallow parts of the aquifer, while there is a delay of 0.5–1.0?years where the groundwater level is at depth 4–10?m. The application demonstrates how spatio-temporal analysis can be utilized for groundwater-recharge estimation through distributed modeling and GIS.