海洋疏浚Mont Carlo数值计算

利用Mont Carlo方法模拟海洋疏浚过程中悬浮泥沙的扩散.结合洋浦近岸海域疏浚工程,计算了悬沙输运轨迹及浓度分布,计算结果较为合理.该模型在近海工程环境影响评价中具有应用价值.     

逆温天气与鄂尔多斯高原中小城镇大气污染

本文根据鄂尔多斯高原逆温天气的形成，讨论了高原地区中小城镇大气污染的时空分布及控制污染的可行性途径。     

铁岭市中心城区餐饮泔水饲料化处理途径探讨

根据铁岭市城区餐饮业分布的特点和泔水收集饲料化处理等问题进行分析探讨,找出一条适合目前国情的餐饮泔水综合利用的有效途径。     

冲模CAD系统中装配图消隐算法

介绍了几种实现模具装配图消隐的方法 ,分析了各种方法的缺陷。根据模具装配图中各零件之间的相互关系 ,对模具零件进行了分类 ,并提出了一种新的实现模具装配图消隐的方法图形实体重构法     

机动车污染防治政策研究

机动车污染已成为城市大气污染的主要污染源之一。并且机动车的噪声污染及废旧汽车的废物污染也越来越严重。中国已初步建立了以《大气污染防治法》为主干，以《环境噪声污染防治法》为辅助的机动车污染防治法规体系，但在管理思想及管理手段和管理环节上仍需进一步完善。     

Nitrogen cycling of atmosphere-plant-soft system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain,Northeast China

The nitrogen(N)distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland (TMCW)and marsh meadow Calamagrostis angustifolia wetland(MMCW)in the Sanjiang plain were studied by a compartment model.The results showed that the N wet deposition amount was 0.757 gN/(m~2.a),and total inorganic N(TIN)was the main body (0.640 gN/(m~2.a)).The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m~2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m~2,respectively.In plant subsystem,the N was mainly stored in root and litter.Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively.The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/(m~2.a)and the values of aboveground were 11.31 and 6.08 gN/(m~2.a),the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/(m~2.a),the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/(m~2.a),the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/(m~2.a),the translocation amounts from root to soil were 14.90 and 13.17 gN/(m~2.a),and the soil(0-15 cm)N net mineralization amounts were 1.94 and 0.55 gN/(m~2.a), respectively.The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N,and the status might induce the degradation of C.angustifolia wetland.     

Preliminary studies on nitrous oxide emissions from the ornithogenic soils on Xi-sha atoll, South China Sea

IntroductionNitrousoxide (N2 O)isoneofthemostimportantgreenhousegases ,anditplaysanimportantroleinthedepletionofstratosphericozone (Crutzen ,1977;Zhu ,2 0 0 4 ) .TheatmosphericN2 Oconcentrationshavebeenincreasingattherateof 0 2 %— 0 3%peryearandthegl…     

Degradation of nitrobenzene in aqueous solution by ozone-ceramic honeycomb

IntroductionAs a promising advanced oxidation technology for watertreatment ,catalytic ozonation has received great attentionforthe efficient degradation of organic compoundsinrecent years(Legube , 1999) . Some studies showed that homogeneousand heterogen…     

南京市城区气溶胶粒度分布特征

以九段串级式撞击采样器对南京市气溶胶进行采样测定。经统计分析发现，气溶胶呈双峰分布，粒度分布规律明显，峰值粒径在0.37μm-0.65μm和4．3μm-5.6μm之间，气溶胶浓度季节变化显著，秋季＞夏秋，秋季颗粒物中细粒子质量百分比较夏季的多，两季质量中位位直径分别为6．5μm,4,4μm，说明与季节变化密切相关。     

森林平均覆盖率与公路水毁因子的关系

通过对公路水毁因子数据和森林平均覆盖率数据的分析 ,研究公路水毁因子和森林平均覆盖率的相关关系 ,求出公路水毁因子和森林平均覆盖率的回归方程 ,从而为公路建设、养护、营运中的问题提供了定量分析的理论依据