某退役后辐照装置的辐射水平监测与评价

依据国家相关标准对某退役后辐照装置周围的辐射水平进行监测与评价,通过数据评价得出该单位辐照装置退役场所未受到放射性污染,其退役后对环境的辐射影响可以忽略。     

顺倾山体采空侧滑致灾的复合应力场研究

本文分析了地下采空情况后认为，山体采空侧动，软弱夹层为决定性条件；其变动范围、速率、规模与性质，与地下采空有关的复合应力场有关。经对观测资料分析、仿真模型试验与仿真数值模拟的对比研究，揭露了顺倾山体的“复合临空面”条件下，“复合变动”的“复合应力场”。     

Development of Stream Water Chemistry during Spring Melt in a Northern Hardwood Forest

The role of snowmelt and subsurface hydrology in determiningthe chemistry of a small headwater stream in the TurkeyLakes Watershed (TLW) was evaluated for the spring meltperiods 1992 to 1996. Spring runoff is the dominanthydrological event at the TLW each year. Processesoccurring within the snowpack during snowmelt wereprincipally responsible for the above-ground changes inchemical fluxes relative to bulk deposition (the effect ofwinter throughfall was minimal). Large changes in chemicalfluxes occurred below ground. Organic matter decomposition,weathering, nitrification, and element cycling are some ofthe more important below-ground processes that operateduring the snow accumulation and ablation season and controlthe composition of the water ultimately appearing in thestream. Maximum stream discharge was accompanied byelevated concentrations of H⁺, NO₃ ^-, K⁺,NH₄ ⁺, DOC, Al and Mn, but reduced levels ofCa²⁺, Mg²⁺, SO₄ ^2- and SiO₂. Theconcentration-discharge relationships were consistent withwater movement through and above the forest floor duringpeak discharge, a flowpath facilitated by rapid infiltrationof meltwater and the existence of a relatively impermeablelayer in the mineral soil creating a perched water table. Averaged over the five periods of snow accumulation andablation, it was estimated that pre-melt stream flow, andwater routed through the forest floor and through the uppermineral soil contributed 9, 28 and 63%, respectively, ofthe discharge measured at the outlet of the catchment. Theforest floor contribution would be greater at peak dischargeand at higher elevations. An end-member mixing modelestimated concentrations of SO₄ ^2-, NO₃ ^-,Cl^-, Ca²⁺, Mg²⁺, Na⁺ and Al that werecomparable to average values measured in the stream. Othervariables (NH₄ ⁺, H⁺, K⁺ and DOC) wereover-estimated implying retention mechanisms operatingoutside the model assumptions.     

真空吸尘系统应用于散货码头的积尘清扫

描述了散货码头粉尘污染现状,分析比较了几种常用的积尘清扫方法。为了有效清扫散货码头的积尘,提出采用集中式真空吸尘系统。文章从系统形式、水力计算方法和工程实例等方面简单介绍了集中式真空吸尘系统。印尼Paiton燃煤电厂码头工程设计采用了集中式真空吸尘系统进行积尘清扫,工程建成投产一年多来,积尘清扫效果明显,有效地降低了粉尘污染。实例说明,真空吸尘是解决散货码头积尘清扫问题较为有效的方式。     

昆明高校实施中水工程的优势与效益分析

提出实施中水工程当为昆明市解决水资源短缺问题的首选,认为新建与已建区应同时并重,分析了高校实施中水工程的优势。     

橡胶助剂析出的原因及防治探析——以武警现行列装鞋靴产品为例

橡胶助剂析出是橡胶制品的常发问题,本文从原料、配方设计、炼胶工艺、硫化工艺、存储条件等方面分析了武警现行鞋靴橡胶助剂析出的原因、形式及危害,提出了防治对策。     

Fly ash content and distribution in lake sediments around a large power station: inferences from magnetic susceptibility analysis

The bulk magnetic susceptibility of sediments from artificial and natural lakes around a large coal-fired power station in NE Spain has been measured. Higher magnetic susceptibility values are found in lake sediments located SE of the power station. This distribution of susceptibility values is compatible with environmental and meterological studies of emissions from the power station, which indicate a dominant SE plume direction. Mineralogical studies, by means of X-ray diffraction and scanning electron microscopy, show that the highest susceptibility values found in the sediments are caused by magnetic iron spinels in the fly ash that is transferred to the environment by the power station particulate emissions. After the quantitative mineralogical studies of fly ash, two different methods of fly ash content determination in the sediments have been devised, showing very similar results. The low background magnetic susceptibility of the sediments in the study area and the high susceptibility resulting from the input of magnetic fly ash particles allows both delimitation of the polluted area around the power station, and quantification of the fly ash input into the natural sediments.     

块体纳米材料的制备及其应用

综述了块体纳米材料的制备技术及其发展 ,指出了常用方法存在的问题 ,并在此基础上论述了块体纳米材料的性能、应用及其发展趋势     

中国污水治理的一个新思考

本文通过对中国地形及气候特征的讨论 ,提出沙漠治水 ,水治沙漠的观点 ,为中国及其他国家的污水治理 ,提供一种新的思路和建议     

中国淘汰滴滴涕的环境影响分析

目前中国仍在生产滴滴涕(DDT),并以其为原料生产三氯杀螨醇作为杀虫剂使用.为评价淘汰DDT对于中国生态环境的影响,采用情景分析的方法,估算了在采取不同的淘汰策略下土壤中DDT残留浓度的变化,以此来评价淘汰DDT的环境影响.与基线情景相比,三种控制情景下DDT的累积生产量都有不同程度的减少,相应土壤中的残留浓度也有不同的下降,且淘汰的速度越快土壤中DDT浓度下降的幅度越大.