甘南县空气变化趋势分析

运用近五年的大气监测数据分析了甘南县大气污染特征,指出了影响甘南县空气质量的主要污染物及变化趋势。     

1969年长江中下游暴雨特征及灾情分析

１９６９年初夏，长江中下游地区，多次出现大雨和暴雨，其主要特点是降水时间长、范围广、来势猛、强度大，致使该地区出现了历史上少见的洪涝灾害，造成了重大经济损失。     

冀津沿海风暴潮的分布特征及成因分析

本文收集整理了最近2045a的史料,论述风暴潮的时空分布特征及区域评价,分析风暴潮的成因及分类,提出风暴潮的预警要点．     

陕西省1993年滑坡灾害特征及其防灾思考

本文介绍了陕西省１９９３年滑坡灾害及其特征；在此基础上提出了今后防滑减灾的对策。     

白洋淀湿地土壤氮素空间分布特征研究

为了了解白洋淀湿地土壤氮素空间分布规律,于2011年4月在研究区内部耕地和芦苇地采集土样进行分析、研究。研究结果显示,湿地土壤氮素含量总体趋势随着土层的加深而减少;表层土壤全氮和碱解氮呈现出西北高、东南低的趋势。耕地土壤氮素含量和变异性均高于芦苇地,反映出人类活动对土壤氮素的空间分布有较大影响。相关性分析显示土壤有机质含量和含水量与氮素联系紧密,是影响其分布的重要因素。     

钦州湾沉积物有机氯农药赋存特征与生态风险

利用GC-ECD测定了钦州湾沉积物中17种有机氯农药的含量,并对其组分分布和来源进行了分析。结果表明,样品中有机氯农药的总量为1.50～129ng/g,滴滴涕(DDTs)浓度为0.59～126ng/g,六六六(HCHs)的浓度为nd～2.65ng/g。有机氯农药的分布特征为茅尾海>钦州外湾,茅尾海东岸>西岸。组分分布特征分析显示,DDTs主要来自于历史积累,林丹在某些采样区域内有近期输入。与国内外不同地区沉积物中有机氯农药残留相比,钦州湾沉积物中有机氯农药污染处于低到中等水平。以沉积物生态风险评估值为基准的分析表明,研究区内DDT含量存在较大的生态风险。     

Farmland damage and its impact on the overlapped areas of cropland and coal resources in the eastern plains of China

The subsidence caused by coal mining in areas where cropland and coal resources overlap in the eastern plains of China with high ground water levels has caused large amounts of water to collect in cropland, significant damage to cropland, and a sharp contradiction between people and land distribution within this region. Systematic analysis and calculation were conducted on these areas by using GIS spatial overlay analysis technology, subsidence and occupied cropland estimation models, and crop yield reduction prediction model to reveal the overlapped characteristics and extent of farmland damage, as well as to evaluate the effects of farmland damage to grain yield, farmland landscape, agricultural population, and dynamical equilibrium of the total cultivated land. Results showed that the overlapped areas of cropland and coal resources on the eastern plains of China occupied an area covering 1.33 × 10⁵ km², which accounted for 31.93% of the total cropland area. In 2020, the accumulative total area of destroyed cropland reached 3.83 × 10³ km², thus reducing grain yield by 9.63 × 10⁸ kg, and increasing the number of landless farmers to 1.91 × 10⁶. Furthermore, the quality and production capacity of cultivated land decreased, farmland landscape patterns changed, land patterns and structures were adjusted, the dynamical equilibrium of the total cultivated land was difficult to guarantee, and social instability increased in coal mining subsidence areas. These findings provided a scientific basis for relevant government departments to enact countermeasures for the coordinative production of coal and grain.     

活性污泥胞外聚合物的组成与结构特点及环境行为

在活性污泥处理系统中,微生物大多以污泥絮体的形式悬浮在水中。胞外聚合物(EPS)作为污泥絮体的重要组成部分,以其独特的聚合结构和化学组成,在污水生物处理系统中起到重要作用。为了更好的描述EPS的环境行为,文章综合了近年来国内外相关的研究成果,首先分析了EPS的来源、化学组成及结构分布,得出EPS中包含蛋白质、多糖、腐殖酸、核酸、糖醛酸及脂类大分子等化学物质,其中蛋白质和多糖之和占总有机物含量的70%~80%;在结构上,EPS分为SB-EPS、LB-EPS和TB-EPS,三者与细胞结合的紧密程度递增,其中所含化学成分比例的不同将使其具有不同的理化特性。其次,文章对EPS的理化特征对污水处理系统的影响,如对系统中微生物降解特性的影响、磷和重金属的吸附等进行了讨论,并总结了EPS中相关的官能团对上述环境行为的贡献。同时,文章还论述了EPS中官能团的亲疏水特性及化学成分对污泥絮体的脱水性、絮凝沉降性能的影响。     

Water conservation due to greywater treatment and reuse in urban setting with specific context to developing countries

In India, the per capita water availability is reducing day by day due to rapid growth in population and increasing water demand. Greywater treatment and reuse is one of the feasible options in developing countries like India to overcome this problem. A greywater collection, treatment and reuse system was designed and implemented in an urban household having a water requirement of 165 liter per capita per day (lpcd) and a greywater generation rate of 80 lpcd. An upflow-downflow greywater treatment plant having a screening, sedimentation, filtration and disinfection as major treatment processes was constructed and treated greywater is used for toilet flushing and to irrigate the vegetables in the backyard of the household. Greywater characterisation indicates that COD and BOD are sufficiently reduced during the treatment and there is also substantially reduction in Escherichia coli count. The payback period of this greywater treatment and reuse system is estimated to be 1.6 year.     

商丘市包河沉积物中正构烷烃的分析

采集了商丘市包河6个位点的表层沉积物,用色谱-质谱对正构烷烃进行了分析,利用正构烷烃碳数分布特征和CPI指标等,对该市区的正构烷烃来源进行初步探讨。结果表明,正构烷烃碳数分布范围多数在nC13-nC31之间,分布类型只有一种,即高分子碳范围,碳优势指数为nC29,1相似文献