近十年(1972-1982)全球生物圈的变化     

M.W.霍尔达盖特  M.卡萨斯  G.F.怀特  赵旭沄 《地理科学进展》1984,3(1):17-23

过去十年中,在认识上的主要进展之一是关于碳、氮、硫、磷及其它元素生物地球化学循环之中的联系,从而说明了将生态圈分属大气圈、水圈、岩石圈等横断面的传统分法之不合理性。  相似文献   

能源与土地利用     

R.W.尼克灵 《地理科学进展》1985,4(3):63-63

《能源与土地利用》是一本包括27篇文章的文集。编者是F.J.布切尔。主要内容是关于能源、规划工作与土地利用的关系问题。全书共601页。分为四部分。  相似文献   

Intersex and sterility in the periwinkle Littorina littorea (Mollusca: Gastropoda) along the Western Scheldt estuary, The Netherlands     

De Wolf H  De Coen W  Backeljau T  Blust R 《Marine environmental research》2001,52(3):249-255

In this study we present the results of an intersex survey of Littorina littorea along the heavily polluted Western Scheldt estuary (the Netherlands), and record for the first time the intersex phenomenon in L. littorea from Dutch waters. Intersex differed significantly between localities and was the highest in the vicinity of the harbours of Antwerp and Vlissingen, as reflected by the I  相似文献   

A comparison of three-dimensional interpolation techniques for plume characterization   总被引：2，自引：0，他引：2  

Jones NL  Davis RJ  Sabbah W 《Ground water》2003,41(4):411-419

Interpolation of contaminant data can present a significant challenge due to sample clustering and sharp gradients in concentration. The research presented in this paper represents a study of commonly used interpolation schemes applied to three-dimensional plume characterization. Kriging, natural neighbor, and inverse distance weighted interpolation were tested on four actual data sets. The accuracy of each scheme was gauged using the cross-validation approach. Each scheme was compared to the other schemes and the effect of various interpolation parameters was studied. The kriging approach resulted in the lowest error at three of the four sites. The simpler and quicker inverse distance weighted approach resulted in a lower interpolation error on the other site and performed well overall. The natural neighbor method had the highest average error at all four sites in spite of the fact that it has been shown to perform well with clustered data. Another unexpected result was that the computationally expensive high order nodal functions resulted in reduced accuracy for the inverse distance weighted and natural neighbor approaches.  相似文献   

Dispersion and toxicity to non-target aquatic organisms of pesticides used to treat sea lice on salmon in net pen enclosures     

Ernst W  Jackman P  Doe K  Page F  Julien G  Mackay K  Sutherland T 《Marine pollution bulletin》2001,42(6):433-444

Pesticides are used extensively in the finfish aquaculture industry to control sea lice infestations on farmed salmon. The most prevalent method of use is to enclose a net pen with an impervious tarpaulin and mix a pesticide solution within that enclosure. After treatment for short periods (1 h) the pesticide solution is released to the environment. Concerns have been raised that there is a potential risk to non-target aquatic organisms from those releases. The fate of dispersing pesticide solutions was measured after six simulated treatments in the Lower Bay of Fundy, New Brunswick. Three simulated treatments were done with azamethiphos and three with cypermethrin. Rhodamine dye was added to all pesticide solutions in order to facilitate tracking of the dispersing plume through real-time measurements of dye concentrations by a flow-through fluorometer coupled with a differential global positioning system (DGPS). Water samples were obtained from within the plumes at various times after release and analysed for pesticide content and toxicity to a benthic amphipod Eohaustorius estuaris. Dye concentrations were detectable for time periods after release which varied from 2 to 5.5 h. Distances travelled by the dye patches ranged from 900 to 3000 m and the dye concentrations at the final sampling period were generally 1/200-1/3000 the pre-release concentrations and cypermethrin concentrations were generally 1/1000-1/2000 the pre-release concentrations. Cypermethrin concentrations in water samples were closely correlated with dye concentrations, indicating that dye analyses were an accurate surrogate for cypermethrin concentrations. Most samples taken after the releases of azamethiphos were not toxic to test organisms in 48 h exposures and none were beyond 20 min post-release. By contrast, almost all samples taken after the release of cypermethrin, even up to 5-h post-release, were toxic. Data indicate the potential to cause toxic effects over areas of hectares from a single release of cypermethrin.  相似文献   

上地幔不相容元素的显交代作用   总被引：2，自引：0，他引：2  

陆琦  周湖云 《地球科学》1996,21(5):553-556,T002

通过矿物微区成分和图象分析，研究了在金伯利岩中发现的多种氧化物矿物的成分、结构特点及其相互关系．指出富含硅酸盐不相容元素的地幔流体交代、熔融先期形成的矿物以及充填作用，形成了近年来我国和南非金伯利岩中发现的多种新矿物相，包括沂蒙矿系列、蒙山矿系列、Ｋ－Ｃｒ柱红石、阿玛科矿、Ｚｒ－Ｔｉ氧化物（锆钛矿）、ＲＥＥ－Ｔｉ氧化物（铈钛矿）等．这些新矿物高度富集了Ｋ，Ｂａ，Ｃａ，Ｓｒ，Ｔｉ，Ｚｒ，ＲＥＥ等不相容元素．研究表明不相容元素的显交代作用可分早、中、晚３个阶段，各阶段不相容元素的富集程度、温压条件及流体的动力学特征等既有明显的差异性，又有一定的继承性  相似文献   

影响地下核爆炸地震监测的地质因素     

Leith  W 朱玉新 《地震科技情报》1996,(4):2-2

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厚层风积黄土覆盖区金矿脉的壤中气汞异常特征及评价     

刘树田  朴寿成  齐清凤  连长云 《吉林大学学报(地球科学版)》1996,(3)

赤峰市莲花山金矿区南部为大片风积黄土覆盖区，壤中气汞测量圈出了许多气汞异常，其中在已开采的４号、５号金矿脉上，气汞异常的形态、规模和强度都较好地反映了矿体的产状和规模。新的工业金矿体的发现，更加证实了壤中气汞测量找金矿脉的有效性。通过壤中气汞异常的评价，认为４号矿脉的北部，５号矿脉的南部，Ｈｇ２号异常的南部及Ｈｇ３号异常的深部有较好的开采远景，而４１号、１５号、２０号石英脉则无工业价值。  相似文献   

辽西地区花岗岩的形成时代   总被引：3，自引：0，他引：3  

孙景贵  连长云 《辽宁地质》1997,(1):24-29

位于华北板块北缘构造－岩浆带内的辽西地区，广泛发育不同类型的花岗岩，作者将其划分为（１）黑云母二长花岗岩系列；（２）含石榴石二长花岗岩系列；（３）花岗闪长－二长岗岩系列，研究结果表明，这３个系列的花岗岩均形成于中生代，是深部物质（下地壳或上地幔）分层熔融的产物，这一认识与花岗岩主体形成古生代观点是截然不同的。  相似文献   

中国农村工业化的经济分析及省际发展水平差异   总被引：55，自引：6，他引：55  

樊杰陶普.  W 《地理学报》1996,51(5):398-407

本文以７个建制镇的农村工业发展的实地调研为基础，对比研究我国乡镇工业发展的一般特点和共性规律，比较深入细致地探讨了以镇区农村工业为主的乡镇企业产生和发展的机制、农村工业发展在农村现代化进程中的作用、农村工业化水平的地域差异性等问题。  相似文献