A review of source tracking techniques for fine sediment within a catchment

Excessive transport of fine sediment, and its associated pollutants, can cause detrimental impacts in aquatic environments. It is therefore important to perform accurate sediment source apportionment to identify hot spots of soil erosion. Various tracers have been adopted, often in combination, to identify sediment source type and its spatial origin; these include fallout radionuclides, geochemical tracers, mineral magnetic properties and bulk and compound-specific stable isotopes. In this review, the applicability of these techniques to particular settings and their advantages and limitations are reviewed. By synthesizing existing approaches, that make use of multiple tracers in combination with measured changes of channel geomorphological attributes, an integrated analysis of tracer profiles in deposited sediments in lakes and reservoirs can be made. Through a multi-scale approach for fine sediment tracking, temporal changes in soil erosion and sediment load can be reconstructed and the consequences of changing catchment practices evaluated. We recommend that long-term, as well as short-term, monitoring of riverine fine sediment and corresponding surface and subsurface sources at nested sites within a catchment are essential. Such monitoring will inform the development and validation of models for predicting dynamics of fine sediment transport as a function of hydro-climatic and geomorphological controls. We highlight that the need for monitoring is particularly important for hilly catchments with complex and changing land use. We recommend that research should be prioritized for sloping farmland-dominated catchments.     

Economic development and its impact on the environment in east coastal zone of China

This paper discusses briefly the elementary characteristics of the east China economic developing zone, and analyses the condition of urban atmospheric pollution, water pollution and ecological damage in this zone at present. It was brought forward that we must pay great attention to the environmental factors, and make the environmental impact assessment and environmental planning in the process of economic development in this zone.     

进水氨氮浓度对静置/好氧/缺氧SBR脱氮除磷性能的影响

在4个序批式反应器(SBR)R1、R2、R3和R4中,以静置段代替传统厌氧段,采用后置缺氧,考察进水氨氮浓度分别为20,30,40,50mg/L对静置/好氧/缺氧SBR脱氮除磷性能的影响.结果表明,R1、R2、R3和R4长期运行中磷去除率分别为82.3%、92.8%、92.6%和89.1%,总氮(TN)去除率分别为97.2%、88.6%、84.5%和72.6%.静置段省却搅拌,但仍起厌氧段作用,仍可实现生物强化除磷.4个反应器好氧段均发生同步硝化-反硝化(SND),分别贡献14.7%、16.6%、17.8%和14.8%的进水后TN量,且后置缺氧段利用糖原驱动反硝化,脱氮效果较好,出水TN分别为0.57,4.43,6.61,13.70mg/L.研究表明,进水氨氮浓度可影响静置释磷、好氧摄磷、反硝化除磷.静置段代替厌氧段的后置缺氧工艺可取得较好脱氮除磷效果,且节约成本,简化工艺.     

长江以北沿海经济贝类中的麻痹性贝毒

应用小白鼠检测方法，对我国长江以北沿岸的经济贝类进行了麻痹性贝毒检测。采样时间 １９９７年９月２３日￣１２月８日。从鸭绿江口到长江口共调查２０个站位，检测经济贝类１４种，样品３８份，其中只有１份样品检测出麻痹性贝毒（６．４Ｍｎ／ｇ），其余样品均为未检出。     

圆孔翻边极限翻边系数的计算

根据板料屈服极限与断面收缩率的关系,推导出圆孔翻边时极限翻边系数的近似计算公式.     

羌塘高原水资源及其开发利用

地跨西藏、新疆、青海3省（区）的羌塘高原是我国青藏高原的主体部分,平均海拔5000m以上,总面积71.6×10⁴km²,占我国陆地面积的7.5％。整个高原严寒干燥,湖泊众多,河流短小,冰川发育,是世界上待开发的一块最高最新的内陆大高原。现有地表、地下迳流约236.15×10⁸m³,水质符合饮用与灌溉要求。但目前基本流入湖泊后破蒸发,如果大量开发迳流势必破坏水循环规律,人为地加速湖泊的消亡。为解决今后工农牧业用水,只能千方百计减少蒸发,取得可利用水量,达到发展经济维持生态平衡的目的。     

卤代烃毒性的化学评价法研究 Ⅰ.吡啶酮卤代烃加合物的FTIR光谱表征

采用气相色谱－付立叶变换红光谱对２－吡啶酮与１１种卤代烃加合物的结构进行了研究，并由ＧＣ／ＭＳ确证。结果表明，吡啶酮与卤代烃发生加合反应，在吡啶酮的环上氮位及环外氧位，生成两种互为同分异构体的加合物－氮位与氧位加物，所有氧位加合物在气相色谱中的保留时间比较氮加合物短。     

康滇地轴东缘岩石与铅锌矿石稀土元素地球化学研究

本文系统地研究了康滇地轴东缘不同时代岩石及不同含矿层位铅锌矿石的稀土元素地球化学特征 ,并加以对比。认为本区地壳演化的不均一性及多期构造岩浆活动反映在不同时代岩石其稀土元素地球化学特征也不相同 ,继承性差。本区矿石的稀土元素分布模式不同于以前报道过的呈W型 ,而是一种新的稀土元素分布模式。不同含矿层位铅锌矿石稀土元素分布模式及其参数类似 ,与岩石差异明显 ,说明主要成矿物质不来自基底及盖层岩石 ,而来自深部 (上地幔 ) ,并且是在同一个成矿期形成的。     

“最小存活种群”和“种群生存力分析”理论在生物多样性评价中的应用——以黔北20万吨/年竹浆林一体化工程中原料林基地建设工程为例

概述了“最小存活种群”和“种群生存力分析”概念、产生过程、研究内容及在生物多样性保护中的应用步骤,并运用该理论,以敏感种豹为关键种,分析了黔北新建20万吨/年竹浆林一体化工程中原料林基地建设工程对拟建项目区生物多样性的影响。分析结果表明,如原料林基地远离豹的栖息地,则栖息地面积尚可满足对豹短期保护（50代）的要求。因此,原料林基地的建设对绝大多数野生动物的影响不大,项目区的生物多样性是可以维持的。     

重视沿海地区控制工业污染出现的新问题

沿海地区对外开放１５年来，外资、合资、集体、个体企业在工业结构中的比重明显增加。它们均要求有良好的投资环境，依靠社会办企业。新兴工业多集中在城镇附近，厂址不少选在较关键的须加强环境保护的地区，如自然保护区，水源保护区等附近。在此情况下，必须按社会主义市场经济规律征收资源费和排污费等；须加强环境规划，建立环境管理系统，有效控制污染源；为保证受损环境得到恢复，必须加强环境建设和环境投资。