浅谈校园景观的构成形态

浅谈校园景观的构成形态山东师范大学附属中学朱新民学校，作为教育下一代的殿堂，其校园景观应该是和谐优美的。唯此，方可对学生施行全方位的陶冶和训练，培养出适应未来发展的一代新人。校园景观是学校这个地域范围内人类文化景观的生动体现。它即包括校风、学校特色、...     

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。     

燃煤产生的NOx控制技术

为减少NOx的危害，改善城市环境与生态环境，必须加强对NOx的排放控制。本文在系统总结和分析国内外燃煤NOx污染控制技术及其经济特点的基础上，提出了我国燃煤NOx污染的控制方向。     

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.