Se and Te mineralization in albitites and prospects of the metasomatites for Au,Salla-Kuolajarvi belt,Northern Karelia

On the basis of the complex of geological features, the eastern flank of the Salla-Pana-Kuolajarvi belt is a prospect structure for gold mineralization in the U-bearing albitites and related acid and mafic metasomatites. Visible tellurides and selenides, which are typical of gold deposits of the Fe-Co-Au-U group in the adjacent territory of Finland within the Salla-Pana-Kuolajarvi belt, were found in the Ozerny occurrence as a result of studies. Native gold is found in association with tellurides. Molybdenite from the occurrence has a high Re content up to 0.3%.     

中国北方农牧交错区交通用地风蚀个例分析-以河北丰宁县坝上大滩镇东沟村为例

对中国北方农牧交错区风蚀变化最为明显的地区进行定点研究,并选取一个小流域作为研究对象。测量了农村交通用地的土壤风蚀状况,计算结果表明：交通工具对十壤作用加速了土壤风蚀过程．扣除车轮挤压地面下降外,交通工具引起的土壤风蚀速率在2．9～3．8cm／a之间。由此可见。在减缓农牧交错区土壤风蚀方面。农村交通道路风蚀问题必须予以考虑。根据社会经济的发展．对交通道路进行固化可减缓这类用地的风蚀状况。     

综合物探方法在湖南香花岭矿田三合圩矿区深部成矿规律研究中的应用

通过在香花岭矿田三合圩矿区开展地面高精度磁法快速掌握了磁异常分布特征,并推测磁异常与NE向断裂带有关,再利用可控源音频大地电磁测深对磁异常进行解析,发现中深部存在连续高阻隆起异常,推断为隐伏岩体,在此基础之上对磁异常进行了半定量反演,发现磁性体呈似层状赋存于岩体外接触带且位于低阻异常带中。利用物探推断成果选择有利部位进行钻探揭露,钻孔ZK502、ZK1601和ZK3001成功验证推断的隐伏岩体并在跳马涧组砂岩中揭露了高品位锡、铅锌多金属矿。结合钻孔、物探成果和地质背景等,对本矿区成矿规律进行了综合分析研究,建立了成矿模型,并圈定了下一步找矿靶区。利用综合物探方法对深部成矿预测具有良好效果。     

山东黄河防洪工程建设占地问题探讨

0引言黄河流经山东省菏泽、济宁、泰安、聊城、德州、济南、淄博、滨州、东营9市,25个县(市、区),河道长628?。由于黄河含沙量高,大量泥沙淤积在河道内,造成目前河床高于两岸背河地面4~6m,设计洪水位高出背河地面8~10m,济南河段的2000年设计防洪水位高出济南市工人新村地面达11.6m,形成举世瞩目的地上悬河,防洪形势十分严峻。1998年“三江”大水之后,党中央、国务院对水利工作做出了一系列重大决策,加大了对大江大河的治理投资力度,加快了黄河下游的治理步伐。经过连续6年的建设,黄河山东段防洪工程整体强度得到明显提高,为战胜可能发生的大…     

Denitrification potential of marsh soils in two natural saline-alkaline wetlands

Little information is available on denitrification potential of marsh soils in natural saline-alkaline wetlands. The denitrification potentials of an open wetland in the floodplain(Erbaifangzi wetland) and a closed wetland(Fulaowenpao wetland) in backwater areas in Jilin Province of Northeast China were monitored by an anaerobic incubation at 30℃ for 25 days. Our results showed that the relative denitrification index(RDI) increased gradually with incubation time, and showed a rapid increase in the first 5 days of incubation. The RDI values declined quickly from surface soils to subsurface soils and then kept a small change in deeper soils along soil profiles over the incubation time. Denitrification proceeded much faster in the top 20 cm soils of open wetland than in the closed wetland, whereas no significant differences in RDI values were observed in deeper soils between both wetlands. The RDIs were significantly negatively correlated with bulk density and sand content, while a significantly positive correlation with clay content, soil organic matter, total nitrogen and phosphorous. The maximum net NO–3-N loss through denitrification in 1 m depth were higher in the open wetland than the closed wetland with higher soil pH values. Future research should be focused on understanding the influencing mechanisms of soil alkalinity.     

Predicting the visualization intensity for interactive spatio-temporal visual analytics: a data-driven view-dependent approach

The continually increasing size of geospatial data sets poses a computational challenge when conducting interactive visual analytics using conventional desktop-based visualization tools. In recent decades, improvements in parallel visualization using state-of-the-art computing techniques have significantly enhanced our capacity to analyse massive geospatial data sets. However, only a few strategies have been developed to maximize the utilization of parallel computing resources to support interactive visualization. In particular, an efficient visualization intensity prediction component is lacking from most existing parallel visualization frameworks. In this study, we propose a data-driven view-dependent visualization intensity prediction method, which can dynamically predict the visualization intensity based on the distribution patterns of spatio-temporal data. The predicted results are used to schedule the allocation of visualization tasks. We integrated this strategy with a parallel visualization system deployed in a compute unified device architecture (CUDA)-enabled graphical processing units (GPUs) cloud. To evaluate the flexibility of this strategy, we performed experiments using dust storm data sets produced from a regional climate model. The results of the experiments showed that the proposed method yields stable and accurate prediction results with acceptable computational overheads under different types of interactive visualization operations. The results also showed that our strategy improves the overall visualization efficiency by incorporating intensity-based scheduling.     

黄河河口拦门沙发育动态

河口拦门沙发育主要取决于河口边界、径流、海洋动力、海面增减水以及河口疏浚等环境要素的相互作用。拦门沙在口门附近呈扇状分布隆起的沙坝,沉积结构为紧密的“铁板沙”.1984-1987年拦门沙自然发育时期,拦门沙长度为7km以上,年平均推进速度1.30km,沙顶高程为-0.1-0.5m;1988-1992年拦门沙人为疏浚发育时期,通过河口疏浚后,拦门沙增长有所减缓,其长度减为4-6km,年平均推进速度降为1.26km,沙顶平均高程下降到-0.7m,相应地减轻了河口地区的防洪压力。     

Nitrogen and phosphorus intake by phytoplankton in the Xiamen Bay

This paper describes a time series experiment examining the nitrogen and phosphorus intake of natural phytoplankton communities by a microcosms approach.Seawater samples containing natural phytoplankton communities were collected from waters around Baozhu Islet in inner Xiamen Bay and around Qingyu Islet in the outer bay.The goal was to elucidate the relationship between phytoplankton population enhancement,the biological removal of nitrogen and phosphorus from the seawater,and the phytoplankton nitrogen an...     

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