Downscaling a twentieth century global climate simulation to the North Sea

The regional ocean model system (ROMS) is used to downscale a 26-year period of the twentieth century 20C3M experiment from the global coupled Bergen climate model (BCM) for the North Sea. Compared to an observational-based climatology, BCM have good results on the mean temperature, except for too low winter temperature. This is connected to a too weak inflow of Atlantic water. The downscaling gives added value to the BCM results by providing regional details, doubling the Atlantic inflow, and improving the mean winter temperature. For mean salinity, BCM has values very close to the climatology, whereas the downscaling becomes too fresh. The downscaling, however, improves the sea surface salinity, the vertical structure, and the Norwegian Coastal Current. It is concluded that the downscaling procedure as presented here is a suitable tool for assessing the future Atlantic inflow and sea temperature in the North Sea based on a global climate projection.     

江苏省锡山市西部地区地下水资源计算模型研究

从地下水运动均衡原理的角度分析江苏省锡山市西部地区第Ⅱ承压含水层天然和现状开采条件下的地下水均衡要素.揭示了该区地下水开采与地面沉降的关系,其中现状开采条件下的75%～80%的开采量来自于粘性土层的压密水量.根据地面沉降的发生机理剖析地面沉降严重发育地区忽略地面沉降影响因子建立的地下水资源计算模型中存在的问题针对存在的问题,提出了地下水可开采资源合理的计算方法,并对融有地面沉降影响因子的地下水资源计算模型的可实现性进行了分析.     

铂族元素矿床特征及成因分类探讨

在收集国内外铂族元素矿床地质特征的基础上,审视了国内外不同学者对铂族元素矿床的分类方案,综合矿床容矿岩石类型、共生元素组合、矿化类型和矿床类型并结合形成环境,对铂族元素矿床进行了系统的总结和分类,划分为四类十二亚类。同时重点论述了具有开发前景的典型铂族元素矿床的基本特征、成矿物质来源和形成环境及成矿的关键问题。     

砂体及其研究价值

本文论述了砂体的意义，砂体的研究价值，砂体的分类，并从多方面阐明了砂体在可地浸砂岩型铀矿找矿工作中的作用。抛砖引玉，力图推进砂体的研究工作，为可地浸砂岩型铀矿的找矿工作服务。     

代内公平、国际贸易与可持续发展

现阶段，不同国家或区域之间商品交流的种类与数量日益增大。由于发达国家与发展中国家在国际贸易中所扮演的角色不同，因此，在等经济价值交换规律的作用下，发展中国家的环境状况逐渐恶化。文章通过构建开放经济的物质流模型，探讨了物质交换行为对系统内部的自然环境的影响，并对1987年日本的物质流动状况进行了案例研究。分析表明，发达国家的经济发展水平在很大程度上依赖于其它国家内部自然资源与环境的支撑作用。     

试论世博会后昆明世博园的可持续发展

’99昆明世博会后，如何实现世博园的可持续发展，成为学术界和世博园管理者不可回避、急需解决的现实问题。文章在论述世博园的性质、现状、面临的问题、影响世博园持续发展的因素的基础上，初步提出出世博园可持续发展的对策。     

21世纪初叶中国治贫反困新思路

21世纪初叶中国的贫困形势是乡村贫困与城市贫困共存，绝对贫困与相对贫困共存，区域性贫困与阶层性贫困共存。文章针对我国反贫困工作中存在的主要问题，提出了建立有效的反贫困治理结构、妥善解决城镇贫困问题、加强国际间合作等对策。     

环洞庭湖区城镇体系发展研究

通过对环洞庭湖区城镇体系发展的历史背景以及现状特征分析，指出其发展过程存在着城市空间格局发展不平衡，产业结构重复严重等问题，在此基础上，提出了相应的对策与发展措施，确保环湖区内城镇体系的持续，快速发展，并最终实现带动区域经济发展的目的。     

Diel changes in the feeding behaviour of Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) in Ellidavatn, a small lake in southwest Iceland

In the lake Ellidavatn, southwest Iceland, the diel activity of Arctic char and brown trout was studied in autumn (September) and spring (April) by removing the fish from gillnets every 3 hours for three days. Additional fish samples, evening and morning, were taken at other times of the year. The catch per unit effort was about 10 times higher during the nighttime than daytime for both char and trout. The median weight of char was lowest near the middle of night (80 g) and highest near the middle of day (140 g). The median weight of trout was also lowest near the middle of night (110 g) and highest near the middle of day (330 g). The main diet of char consisted of the cladoceran Eurycercus lamellatus in September and chironomid larvae in April and the main diet of trout was always sticklebacks. In autumn and spring, the feeding was nocturnal in the char but crepuscular in the trout. The median stomach content of char was highest at dawn (0.52% of body weight) and lowest at dusk (0.14% of body weight). It is proposed that nocturnal char shift through the bottom substrate in search for prey. The median stomach content of trout was highest at 09.00–18.00 and 24.00–03.00 hours (0.13–0.18% of body weight) and lowest at 03.00–06.00 and 18.00–21.00 hours (0.02–0.07% of body weight). Different feeding times may help to secure mutual coexistence of char and trout in a small lake. In autumn and spring, the average daily consumption of char was about 0.8% of body weight, less than half their maximum food intake.