水源水质现状监测及变化趋势分析研究

在从汤溇西侧离岸约2 km的太湖中取水,作为新建40万m3/d水厂水源的背景下。课题组从取水口附近太湖水质现状监测、富营养化水平分析及水质变化趋势分析等方面入手,为项目水资源论证提供水质可行性依据：水质安全可控、变化趋势稳定。     

NONPARAMETRIC APPROACHES TO ENVIRONMENTAL IMPACT ASSESSMENT1

ABSTRACT: The interesting developments in non-parainetric testing and estimation methods presented in the upcoming sequence of nine papers are evaluated, compared, and put into proper perspective. Because a deterioration in water quality constitutes a direct threat to human health, it is of utmost importance to have flexible non-parametric methods available for detecting and describing trends in water quality time series. A distinct advantage of nonparametric tests is that they are usually very effective when applied to “messy” environmental data which may, for example, contain many missing observations and not be normally distributed. By applying their enhanced approaches for nonparametric methods to water quality time series, as well as employing well designed simulation experiments, the authors of the papers clearly demonstrate the efficacy of utilizing nonparametric tests in environmental impact assessment.     

APPLICABILITY OF THE t-TEST FOR DETECTING TRENDS IN WATER QUALITY VARIABLES1

ABSTRACT: A major concern in managing water resources is whether or not water quality variables have changed over time or space. The two-sample Student's t-test is probably the most commonly used statistical test for this purpose. Given that the underlying assumptions of the test may often be violated by water quality variables, a major concern regarding applicability of the test arises. This paper reviews and synthesizes available information in order to examine the effects of non-normality, unequal variances, serial dependence, and seasonality on the performance of the two-sample t-test. The results suggest the t-test is robust for non-normal distributions if the distributions have the same shape (either symmetric or skewed) and sample sizes are equal. The t-test is also robust for unequal variances if the sample sizes are equal. The t-test appears not to be robust when: 1) samples come from two distributions of different shape, 2) samples have unequal variances and unequal sample sizes, 3) serial dependence in observations is present, or 4) seasonal changes, in concentration are present and not removed.     

废钢震荡盘整加剧 后期价格渐趋弱化

探讨了废钢行业目前面临的焦点问题,分析了2012年国内废钢消耗使用现状及价格走势,指出随着我国钢材市场供过于求局面的长期存在,2013年的废钢行情依然复杂多变。     

楚雄市空气环境质量状况、变化趋势及对策

根据楚雄市"十五"期间空气环境质量监测结果,对楚雄市空气环境质量状况、变化趋势进行分析、研究,并提出改善空气环境质量的对策、建议.     

NEWS

Abstract

In the light of the historical substantial data (covering a 70-year period) collected in the Lower Jingjiang segment and aided by topological grey method, here we attempt to characterize the occurrence and future trend of flood calamities in the study area. Our findings indicate that overall the high-frequent flood disasters with middle to lower damage prevail at present. A series of dramatic flood waves will appear in the years of 2016, 2022, 2030 and 2042, particularly a destructive flood will occur between 2041 and 2045 in the Lower Jingjiang reaches. Typical of sensitive response to flood hazards in close association with its special geographical location, the lower Jingjiang segment hereby can reflect the development trend of floods in the middle Yangtze reaches. According to the results, a good fitness was revealed between the prediction and practical values. This actually hints that the topological grey method is an effective mathematical means of resolving problems containing uncertainty and indetermination, thus providing valuable information for the flood prediction in the middle Yangtze catchment.     

石河子市环境空气质量变化趋势浅析

根据石河子市1982-2001年空气中SO2、NOx、TSP和降尘等大气污染物浓度的变化情况,分析其空气质量变化的原因和条件,并用Spearman秩相关系数法对其变化趋势进行了分析,得出石河子市环境空气质量有所好转,SO2、NOx、TSP、降尘浓度均有不同程度的下降。并对干旱地区的城市化建设、污染控制及改善环境质量作了有益的探讨。     

部队防化救援装备现状及其发展趋势

本文基于我国化学事故多发,面临着严峻的形势,介绍了部队在处置化学事故时承担的主要任务,以及解放军、公安消防部队和武警部队防化救援装备的现状,并对其趋势进行了展望。     

火灾探测报警系统及其可靠性研究

随着经济的发展和城市化进程的加速,火灾探测报警系统作为早期发现火灾的重要设备,在火灾防控中发挥着越来越重要的作用,火灾探测报警系统及其可靠性也成为当前研究热点。本文介绍了火灾探测报警系统及其可靠性的研究现状,分析了火灾探测报警系统及其可靠性研究存在的问题,针对存在的问题,指出了火灾探测报警系统朝着智能化、标准化、网络化的发展方向,以及火灾探测报警系统可靠性研究的发展趋势,建立火灾探测报警系统数据库,并找出适用于火灾探测报警系统可靠性分析方法。     

Positive remediation on sedimentary P by combination of capping with calcium hydroxide and oxidation with perhydrol

The capping is called passive remediation because the sedimentary P was released and then immobilized by the capping materials. However, the release depends on the environmental conditions. Therefore, a hypothesis was proposed that the oxidant was used to accelerate sedimentary P release and the capping material was used to capture those released P. It is positive remediation to reduce sedimentary P amount. The results show that soluble reactive phosphorus（SRP） concentration in the overlying wat...