大气污染总量控制GA方法对气象因子的敏感性

通过数值模拟试验,研究了基于遗传算法(GA)的大气污染总量控制方法对风向、风速、稳定度三个最重要的气象因子的敏感性。结果表明,用基于遗传算法的大气污染总量控制方法所求得的区域允许排放总量以及允许排放总量在各污染源之间的分配方案,对风向、风速、稳定度三个气象因子都敏感,从而验证了该方法的稳定性和可靠性。     

论浮顶罐大呼吸非甲烷总烃排放计算公式参数取值

目前原油库建设环评需预测非甲烷总烃对周边居民的影响,进而提出卫生防护距离。大连、岙山等国家战略储备基地根据预测提出的卫生防护距离对居民进行拆迁安置．致使工程经济可行性大为降低。采用实测与美国推荐大气预测模式对浮顶罐非甲烷总烃对环境质量的影响发现其差异较大。文章在分析其差异的基础上,对污染源强的参数取值进行了详细论证。以实测为基础,论述了计算公式中参数的取值依据,进而论证了当前浮顶罐运行段采取不防腐,依靠原油自身物性,即可达到防腐和减少非甲烷总烃的双重效果。     

浸渍活性炭脱除含硫气体研究进展

介绍了浸渍活性炭脱除含硫气体机理的研究进展,归纳了炭表面化学环境,金属离子及水对转化途径和反应机理的影响,对进气组成和温度、压力、空速等操作条件对脱硫效率的影响进行了讨论,举例说明了浸溃活性炭脱硫应用情况,分析了浸渍活性炭失活原因,对再生方法进行了简要总结。     

松花江哈尔滨段二维水质模型参数敏感性分析

运用灵敏度与线性回归的方法,分析了松花江哈尔滨段二维水质模型中参数的敏感性。结果可知：污水排放量（Qp）=污水排放浓度（Cp）〉河流本底浓度（Ch）〉流速（u）〉横向扩散系数（My）〉降解系数（Kl）;污水流量（Qp）、污水排放浓度（Cp）、河流本底浓度（Cb）与预测断面污染物浓度均呈正向完全线性相关;降解系数（Kl）与预测断面污染物浓度呈负向完全线性相关;流速（u）和横向扩散系数（My）均与预测断面污染物浓度满足幂函数方程,且呈负向完全线性相关;在搜集资料时,要特别注意对流速小数位数的保留。     

土-岩界面重金属行为的研究进展

随着多环境介质问题研究的深入,重金属在跨介质迁移时产生的界面效应问题倍受人们关注。土－岩界面因其特有的微环境结构和特性,使重金属在该界面的行为过程既部分地表现出与在两侧的环境介质运移过程的动力学特征及机制,又有其独特的特性。有关研究表明自然因素及人为活动等引起的环境参数的变化对土－岩界面的重金属行为有显著影响。今后土－岩界面的重金属行为研究应在目前研究状况的基础上立足于为土壤污染的修复提供技术支撑。     

流动沙丘上生态垫防风固沙效果初步评价

北京及其周边地区分布的大量裸露沙荒地是北京近年来沙尘暴频发的主要沙源之一,而增加其地表覆盖状况则是遏止就地扬沙起尘的有效措施之一。以北京西北部河北宣化黄羊滩为例,对流动沙丘上铺设生态垫并栽植灌木的防风固沙效果进行了初步研究。研究结果表明,与沙柳沙障相比,生态垫确实可以降低近地表的输沙率,提高生态垫下土壤的养分含量,一定程度上提高柠条的地径和高度,可见生态垫是一种很好的促进流沙固定和植被恢复的地表覆盖材料;与其它两种生态垫铺设方式(品字状和带状)相比,全铺可以显著降低近地表的输沙率,提高其下土壤的养分含量,但柠条的生长状况却略差,这可能与全铺降低了小雨入渗的可能性有关;就两种部分铺设的方式而言,无论从降低近地表的输沙率还是促进柠条的生长上来看,品字状都明显优于带状。从生态和经济的角度综合考虑,品字状铺设显然是该区域流沙防治措施中较好的选择。     

The use of vector transition in the modelling of intraherd foot-and-mouth disease

Foot-and-mouth disease (FMD) is a highly contagious viral infection of cattle, sheep, goats and pigs, with complex epidemiological interactions. State-transition simulation models have traditionally catered for complex modelling, yielding detailed representations that are well suited as predictive scenarios. However, results of serological investigations show a variance in antibody levels between segregated age groups on managed farms, and this has further complicated an intraherd model to the extent that a state-transition technique would become cumbersome. Moreover, the distinction between the acute and milder forms of the disease adds three more states to a conventional SIR framework, creating an APRISM model. Consequently a vector-transition technique has been employed. Vector-transition combines daily changes (in both the viral output of infected animals and the antibody titres of susceptibles) with the transition of herd animals between disease states. This means that the probability and herd matrices used in the state-transition approach are no longer required; the model is thus simplified and the processing load reduced. Vector-transition has direct applicability to FMD but could also be used to model similar micropopulation diseases.     

土壤侵蚀的环境磁学监测方法

依据土壤、沉积物磁性理论,河流或湖泊的悬移物和沉积物记载了其产地的磁信息,根据它们的磁性参数可以追踪其来源及分布范围;根据表土磁性增强现象,可以采用土壤剖面磁性变化方法来判断土壤侵蚀程度;另外,应用“磁性示踪剂”也是研究土壤侵蚀的有效手段。文章就这方面的国内外研究进展情况加以阐述,并对该方法的优缺点及发展前景提出看法。     

Exploring the Relationship Between Hydrologic Parameters and Nutrient Loads Using Digital Elevation Model and GIS – A Case Study from Sugarcreek Headwaters, Ohio, U.S.A.

Ohio is typical among the Midwestern and Eastern United States with high levels of water pollutants, the main sources being from agriculture. In this study, we used a digital elevation model in conjunction with hydrological indices to determine the role of landscape complexity affecting the spatial and temporal variation in pollutant levels, in one of the most impaired headwater streams in Ohio. More than eighty five percent of the study area is dominated by agriculture. Spatial distribution of slope (S), altitude and wetness index along with other watershed parameters such as flow direction, flow accumulation, stream networks, flow stream orders and erosion index were used within a Geographic Information Systems framework to quantify variation in nitrate and phosphate loads to headwater streams. Stream monitoring data for nutrient loads were used to correlate the observed spatial and temporal patterns with hydrological parameters using multiple linear regressions. Results from the wetness index calculated from a digital elevation model suggested a range of 0.10–16.39, with more than 35% having values less than 4.0. A Revised Universal Soil Loss Equation (RUSLE) predicted soil loss in the range of 0.01–4.0 t/ha/yr. Nitrate nitrogen levels in the study area paralleled precipitation patterns over time, with higher nitrate levels corresponding to high precipitation. Atmospheric deposition through precipitation could explain approximately 35% of total nitrate levels observed in streams. Among the different topographic variables and hydrological indices, results from the step-wise multiple regression suggested the following best predictors, (1) elevation range and upstream flow length for nitrate, (2) flow direction and upstream flow length for ammonia-nitrogen and slope, and (3) elevation range for phosphate levels. Differences in the landscape models observed for nitrate, phosphate and ammonia-nitrogen in the surface waters were attributed partly to differences in the chemical activity and source strengths of the different forms of these nutrients through agricultural management practices. The results identify geomorphologic and landscape characteristics that influence pollutant levels in the study area.     

诺砂试制经济型地面砖的研究

论述了对诺砂采用压制成型法试制低成本地面砖的工艺流程、试验过程及其结果分析,并对其反应机理进行了简单的探讨,为诺砂的综合利用提供了一定的参考.