天然水、土壤和岩石中金与腐殖质的相互作用(地球化学和分析综述)

对天然水、土壤和岩石中金与腐殖质相互作用的结果及Au一腐殖酸和AUCL-腐殖酸在体系中相互作用的实验资料进行了研究。研究表明，金与腐殖酸有机质形成配合物的过程，乃是表生带中金的迁移和富集机制的一个重要方面，决定了从联质矿石中萃取金的工艺特点，影响到岩石、矿石、土壤和天然水中金的测定准确性，进而对金矿床普查和评价的效率有决定性的影响。     

保险岂能当“包险”

机动车参加保险,对减少交通事故造成的车辆赔偿纠纷,帮助车主减少损失起到很好的补救作用,但也有部分驾驶员因车保了险,导致其安全意识放松,各种违章现象时有发生,存有“反正车辆保了险,出事找保险部门赔”的糊涂观念。事实恰恰相反,如果是明知故犯,保险部门不仅不予理赔,还落个人财两空下场。     

离子色谱法分离La系元素——电子选择性不同可同时测定过渡金属和镧系金属

稀土元素的测定,特别是镧系元素,在各种工业中是很重要的。例如,在核动力工业中,对处置放射燃料的镧系分裂产物的测定就是称为燃耗(burnup)参数的衡量尺度。在矿业中各种岩石样中的痕量镧系元素的测量有助于勘探者寻找镧系矿藏。 同样,地质样中痕量镧系元素的浓度可为判断一些地质形成过程提供线索。岩石中镧系元素的浓度一般都不随时间而变。因此分析镧系物对探索地质成因及其运动可提供一个“指痕”(fingerprint),因为没有任何两个取自不同地点的样品是具有相同断     

底辟作用和重力构造会议

<正> 引言自 H.Ramberg(1963)在实验室开始他的著名的模拟底辟构造研究,并将这些模拟研究应用于解释造山带主要构造的成因以来,至今将近二十年了。在此期间,构造地质学思想发生了一场革命,即基于地球板块构造运动的水平构造的思想比与底辟有关的垂直构造的思想来说占优势地位。因此考虑,应及时地回顾一下底辟作用在区域变形中的相对作用,于是构造研究组(隶属伦敦地质学会)于1980年3月25-     

Critical loads for Finnish lakes: comparison of three steady-state models

Three simple steady-state water-chemistry models are used to calculate critical loads of sulfur for lakes in Finland. Because of the high concentrations of organic matter in Finnish lakes, the influence of organic anions on the calculation of critical loads has been given special attention. The first two methods are well known ion-balance methods which have been used in many previous lake-acidification studies. The third method, developed for this study, includes the numerical solution of equilibrium equations for organic anions, inorganic carbon species and inorganic monomeric aluminum. The original pH and aluminum concentration of the lakes are estimated with this model, and a method to estimate the original acid neutralizing capacity (ANC) by simulating a Gran-titration is also tested on the lake data. Uncertainty in the predictions is estimated by varying the most critical model parameters.     

The response of stream-dwelling fish to liming

The fish fauna in 22 limed and seven unlimed small streams was monitored using yearly electrofishing to assess the effects of liming on species occurrence and abundance. The liming techniques were divided into three main methods, lake liming, doser liming and wetland liming, to evaluate whether different strategies had different effects on the fish fauna. The predominant species at the investigated stations were salmonids, mainly brown trout (Salmo trutta) and Atlantic salmon (Salmo salar). Other species generally occurred in low numbers. The average number of fish species did not increase significantly after liming, which was probably due to recolonization difficulties caused by the frequent occurrence of migration obstacles in the streams. After liming the density of salmonids increased significantly, irrespective of the liming method. Other fish species showed no general increase, but in individual streams significant increases of European minnow (Phoxinus phoxinus) and bullhead (Cottus gobio) occurred. Some unlimed streams had acid spates with a pH below 6, which immediately lowered the numbers of salmonid parr. Other unlimed streams lost fish species progressively due to increasing acidification. pH, and probably increased levels of metals, were the major factors regulating the fish fauna. Few examples of biotic interactions were observed, but with an increase of Atlantic salmon parr after liming, brown trout abundances decreased in three streams.     

Fluxes of ions in precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia

A study was carried out to determine the chemical composition of bulk precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia. The mean weekly rainfall recorded during the period of study was 63.2 mm. Throughfall, stemflow and canopy interception of incident precipitation were 77.1%, 1.2% and 21.7% respectively. Bulk precipitation, througfall and stemflow were acidic, the pH recorded being 4.37, 4.71 and 4.15 respectively. In all cases the dominant ions were NO3, SO4, Cl, NH4, K, Ca and Na. Of the ions studied Ca, K, Cl, SO4, Mg and Mn showed net increases in passing through the forest canopy, while NH4, Na, NO3, Zn, H and Fe showed net retention. This study shows that the urban environment of Kuala Lumpur contributes considerable amounts of materials to the atmosphere, as reflected by the high ionic contents in bulk precipitation, throughfall and stemflow.     

Factors affecting trace-metal bioaccumulation in Finnish headwater lakes

Fourteen unpolluted Finnish headwater lakes with pH values varying from 4.8 to 7.0 were studied for trace-metal concentrations in water, sediment, aquatic plants (Nuphar luteum L., Sparganium sp.), aquatic insect larvae (Limnophilus sp., Phryganea sp.) and fish (Esox lucius L., Perca fluviatilis L., Coregonus sp., Salvelinus fontinalis L., Salmo trutta L.). Trace-metal deposition was estimated by analysing the snowpack. Non-parametric correlation analysis was carried out between trace metal concentrations in biota and pH, ANC, TOC, CA + Mg concentration in water and a given metal concentration in water and sediment. Bioaccumulation of several trace metals increased with increasing acidity and decreasing ANC in water. This was especially true for Pb and Cd. Aquatic plants were, in general, the best indicator group concerning differences in trace-metal bioaccumulation in lakes with different acidity. There was some evidence that a higher concentration of TOC in water may reduce bioaccumulation of Pb, Cd and Zn in aquatic plants and fish. The copper concentration in sediment was the only background variable explaining Cu concentration in aquatic insects. Multivariate analysis of the whole background data gave comparable preliminary results. Over 80% of the trace metal concentrations in biota of different lakes was explained by the background variables. In general, elevated concentrations of most of these trace metals can be expected to occur in the biota of acidified low calcareous lakes.