乔治王岛菲尔德斯半岛火山岩地球化学及生成与演化

本文详细讨论了南极菲尔德斯半岛岛弧火山岩的岩石化学、微量元素,稀土元素及同位素地球化学特征。区内务类火山岩普遍具高铝的特点,且有着相似的稀土元素分布模式。岩石富集Sr、Rb、Ba、K、Th等高度不相容元素,而极度亏损Ni、Cr、等过渡元素。Nd、Sr、Pb、O同位素特征显示岩石的幔源性质。主元素、微量元素混合模拟计算表明:本区高铝玄武岩可由上地幔中等程度(20—25％)部分熔融形成的橄榄拉斑质原始岩浆经一定程度的橄榄石(12％)和单斜辉石(28％)的分离结晶而成。以斜长石和辉石为主的分离结晶作用控制了本区岩石的演化。     

东太湖的由来及其演变趋势

在太湖的历史中,洞庭东山仅仅是太湖中的一个孤岛,由于它周围逐步被淤后和太湖平原连结在一起形成了东山半岛,东山半岛把整个大太湖水面分隔成“东太湖”与“西太湖”。“东太湖”的面积只占整个大太湖总面积的5.6%,而汛期时,其行洪水量却占整个太湖行洪总量的71.9%。治理东太湖,延长太湖的衰亡过程,对太湖地区的防洪抗灾工作有很重要的积极意义。     

Children's Access to Local Environments: A case-study of Christchurch,New Zealand

This article provides a case-study of variability in children's independent access to their local environments in the New Zealand city of Christchurch. It is based on research with children in middle childhood, parents and teachers in four schools in Christchurch, each selected on the basis of variables hypothesised to impact on children's access to their local areas. The paper outlines why such independent access is of value, not only for children, but also for adults responsible for their safety, for the wider environment and for the local community. Variability within Christchurch is related to the socio-spatial nature of local environments. International comparisons are also made, drawing out the implications of differing cultural contexts for the pursuit of child-friendly cities. The article explores the role of social traps in impeding the creation of a more sustainable, child-friendly city.     

Bioecological characteristics of segetal flora in the Middle Urals

The data on the biological diversity, bioecological features, and geographic variations of segetal plants in the Middle Urals are presented for the first time. It has been shown that apophytic and anthropophytic groups are equally represented among them. Each group is characterized, and the phytocoenotic activity of segetal plants is considered.     

对索风营水电站坝址区堆积体勘察设计的几点认识

乌江索风营水电站坝址区分布有7个堆积体,其成因有崩塌堆积、蠕变—拉裂—崩解堆积、塌滑堆积及混和堆积等。在勘察过程中我们采用了地质测绘、钻探、硐探、物探、科研试验等多种勘察方法与手段,在勘察成果基础上对堆积体稳定性进行了分析,并结合对工程的不同影响提出了相应的工程处理措施。     

Yttrium Normalisation: a New Tool for Detection of Chromium Contamination in Soil Samples

The measurement of chromium and yttrium concentration could give a chance to detect 5–10 times less chromium contamination in soil by using the yttrium normalisation method. The principle of the method is the following: elements such as chromium and yttrium exist naturally in the soil in a strongly bonded form. Therefore, in a noncontaminated area there should be a close correlation between the yttrium and chromium concentrations. If the measured Cr concentration in a sample is not on the Cr–Y trend line then the distance of plotted point from the line indicates the amount of anthropogenic chromium. Anthropogenic chromium can be detected only in the case when the contamination does not contain yttrium. This theory was tested in an agricultural–toxicological field experiment where Cr(VI) was added to the soil. Applying the yttrium normalisation method a much smaller anthropogenic effect was detected than by other evaluation methods.     

加拿大北极地区雪化学成分的初步研究

利用ＩＣＰ－ＡＥＳ，ＩＣＰ－ＭＳ，ＩＣ测定法，测定了北极地区不同纬度的１７个雪样品的化学成分。结果显示，在被测试的３２种化学成分中，１４种化学成分被检测出。用富集因子法判断了雪中化学成分的４种可能发生源，即人为活动源，地壳源，海洋源和混合源。计算Ｓ／Ｎａ比值发现ＳＯ＾２－，ＮＯ＾－３主要来自人为活动源。     

长江口邻近海域表层沉积物中的细菌藿多醇及对低氧区的响应判别

作为新型细菌生物标志物的细菌藿多醇（bacteriohopanepolyols,BHPs）在有机质来源追踪和环境变化响应等方面有明确的指示作用.本文应用高效液相色谱串联大气压化学电离源质谱法（HPLC-APCI-MS）分析,在解析长江口邻近海域表层沉积物中BHPs的组成、分布和来源特征基础上,探讨了BHPs对长江口邻近海域季节性低氧的指示作用.结果表明,长江口邻近海域表层沉积物中共检测出12种BHPs,其含量范围（以TOC计）为3.79~269 μg·g^-1.BHPs以细菌藿四醇（bacteriohopanetetrol,BHT）、2-甲基BHT、氨基BHPs和腺苷藿烷及同系物为主要组分,分别占总量的40%、22%、12%和4%.各组分含量及相应指标呈现出明显的空间变化趋势,其中,主要来源于海洋自生来源的BHT呈现明显的"离岸增加"趋势;主要为陆源贡献的腺苷藿烷等土壤标志物BHPs呈现明显的"离岸降低"特征.Rsoil指数呈现出与腺苷藿烷等土壤标志物BHPs相似的空间分布格局,其陆源有机质贡献从近岸的61.5%下降至外海的1.66%,表明长江口邻近海域近岸有机质主要为陆源输入,而外海主要为海源贡献.细菌藿四醇同分异构体BHT-Ⅱ来源于厌氧氨氧化细菌,其相对含量的高值区与长江口低氧区分布相一致,且与底层水溶解氧（DO）含量呈显著负相关,表明低氧环境有利于BHT-Ⅱ的生成,BHT-Ⅱ可用于指示海洋低氧区环境特征.     

Pesticide residues in products of plant origin in the European Union

The results of a co-ordinated monitoring programme for pesticide residues in the European Union and Norway carried out in 1996 and 1997 are presented. The aim of this programme is to work towards a system, which makes it possible to estimate actual dietary pesticide intake for the population of the European Union. Based on a statistically dérived sampling plan and within the limited number of pesticides/commodities analysed, the most critical pesticides (benomyl group and dithiocarbamates) and commodities (mandarine and lettuce) were identified. In case of detected non-compliances, repeated sampling and, if necessary, enforcement actions are to be taken by national authorities. The programme will be continued in the next years.