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1.
大运河常州段水质变化及其影响因素   总被引:1,自引:0,他引:1  
柳洪 Rob  DB 《上海环境科学》1994,13(8):30-32,39
根据目前已建立的基本水质数据库,对大运河常州段的水质现状和趋势作了分析。利用质量平衡,建立了污染物量和水质之间的直观关系,发展了繁忙的机动船只动输运河产生油污染的同时,会对水体中溶解氧产生有的贡献。  相似文献   
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The paper gives an overview of approaches towards ecological networks throughout Europe.It does not intend to present a complete picture,but to highlight comon developments within countries and regions and show common principles and differences between countries and regions that have to be taken into account when developing a joint European intiative,Countries or regions that have not been included can be active in the same way ,but information was not accessible to be authors for different reasons.This overview shows the comparable trends in decline of landscapes and the diversity in approaches to biodiversity conservation and nature conservation planning.Understanding the differences and common issues are of utmost imprtance to generalise common principles and to understand the way neighbours and other European partners approach problems.  相似文献   
3.
We propose a new methodology for predicting areas with a strong potential for radon (222Rn) exhalation at the soil surface. This methodology is based on the Rn exhalation rate quantification, starting from a precise characterisation of the main local geological and pedological parameters that control the radon source and its transport to the soil/atmosphere interface. It combines a cross mapping analysis of these parameters into a geographic information system with a model of the Rn vertical transport by diffusion in the soil. The rock and soil chemical and physical properties define the entry parameters of this code (named TRACHGEO) which calculates the radon flux density at the surface. This methodology is validated from in situ measurements of radon levels at the soil/atmosphere interface and in dwellings. We apply this approach to an area located in western France and characterised by a basement displaying a heterogeneous radon source potential, as previously demonstrated by lelsch et al. (J. Environ. Radioactivity 53(1) (2001) 75). The new results obtained show that spatial heterogeneity of pedological characteristics in addition to basement geochemistry--must be taken into account to improve the mapping resolution. The TRACHGEO forecasts explain the Rn exhalation variability on a larger scale and in general correlate well with in situ observations. Moreover, the radon-prone sectors identified by this approach generally correspond to the location of the dwellings showing the highest radon concentrations.  相似文献   
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TRACI, a model based on the physical mechanisms governing the migration of radon in unsaturated soils, has been developed to evaluate the radon flux density at the surface of uranium mill tailings. To check the validity of the TRACI model and the effectiveness of cover layers, an in situ study was launched in 1997 with the French uranium mining company, COGEMA. The study consisted of continuous measurements of moisture content, suction, radon concentration at various depths inside a UMT cover, and flux density at its surface. An initial analysis has shown that radon concentration and flux density, as calculated with a steady-state diffusion model using monthly averaged moisture contents, are in good agreement with measured monthly averaged concentrations and flux densities.  相似文献   
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大气扩散模式在环境管理信息系统中的应用   总被引:1,自引:0,他引:1  
本文根据常州市环境管理信息系统(CZEMIS)合理选择大气扩散模式的基本原则,概述了大气扩散的基本模式,并对基本模式进行有效的合成。利用软件工程思想对大气扩散模式进行结构化设计,形成大气环境质量预测软件。   相似文献   
8.
沿海水域的富营养化是一个在全球范围内需要付出巨大社会代价的严重的环境问题.在斯卡格拉克海峡东部,富营养化的降低计划通过氮输入量的减少逐步实现,但目前还不清楚如何去减少氮的输入量.其中一个可能的方法是养殖紫贻贝等滤食性生物,这种贻贝能够在生产海产品、饲料和农业肥料的同时也能够除去氮,从而将营养盐由海洋再循环到了陆地上.在瑞典西海岸的古尔马峡湾,我们对贻贝养殖可能对氮循环产生的影响进行了模拟.结果显示,该峡湾口地区氮的净输送量(溶解氮和颗粒状氮的总和)下降了20%.现有的商业贻贝养殖场已经免费提供了这种服务,但它对社会带来的利益将会远远大于这些.我们建议,不应该向贻贝饲养人支付劳动报酬,而应引入营养交换体制以提高沿海水域的状况.在这样的背景下提出了一个通过养殖贻贝来替代在吕瑟希尔社区的污水处理厂中消减氮含量的选择方案.生体毒素的聚积已被确定为瑞典的商业贻贝养殖进一步扩大方面的最大障碍,但这一问题似乎可以通过新技术和管理战略得以解决.在现有和可能的规定和支付费用的基础上,我们提出了一些可能会实现双赢的解决方案.  相似文献   
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智能化建筑=绿色建筑   总被引:1,自引:0,他引:1  
在过去的十年中 ,“智能化建筑”这个术语已经被广泛地用于描述新的高技术建筑物 .这一术语在亚洲已经相当流行 ,那里有许多最大的新建筑建设项目 .智能化建筑的概念自然与对环境无害的“绿色建筑物”有关 .本文对 Brengel技术中心作了介绍 ,它是由美国绿色建筑理事会 (USGBC)能源和环境设计指导 (LEED)绿色建筑评定体系首批认证的 12个建筑物之一 .  相似文献   
10.
An experimental study concerning the transport of 222Rn in uranium mill tailings (UMTs) and in the cover layer was launched in 1997 with the participation of the French uranium mining company (COGEMA). Evaluation of the cover layer's effectiveness in reducing 222Rn flux emanating from UMTs was one of its objectives. In the first phase, the 222Rn flux densities were measured regularly on a UMT layer. In the second phase, the UMT was covered with a one-meter layer of compacted material consisting of crushed waste rock derived from mining activities. Radon-222 flux was then measured at the surface of this cover layer. Observations were compared with radon flux calculated using TRACI, a model for vertical water and gas flow and radon transport. The results show that the calculations bear a fair resemblance to the observations in both cases. They also show that the effectiveness of the cover layer calculated with TRACI, using the thickness and textural properties of the cover material, is very close to the measured effectiveness.  相似文献   
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