微波消解-氢化物发生原子荧光光度法测定土壤中的汞

建立了微波消解-氢化物发生原子荧光光度法测定土壤中汞的方法。对微波消解条件、样品粒度等进行了优化,用3 mL硝酸和2 mL盐酸的混合酸作消解溶剂,在设定的微波条件下汞提取完全。用3%的盐酸作为反应载流,0.01%硼氢化钾与0.5%氢氧化钠的混合液为还原剂,直接定容后应用HG-AFS测定,通过测定国家标准参考物质和加标回...     

Impact of socioeconomic and meteorological factors on reservoirs’ air quality: a case in the Three Gorges Reservoir of Chongqing (TGRC), China over a 10-year period

Environmental Science and Pollution Research - The Three Gorges Dam’s construction and industrial transfer have resulted in a new air pollution pattern with the potential to threaten the...     

胶州市生态系统承载机制及实证研究

本文立足于城市生态系统的结构与功能，探讨了系统内部资源、环境对人类社会经济活动的承载机制，总结了城市生态系统承载机制的特点，认为城市生态系统承载机制具有客观存在性、阈值性、相对性等特点，并从城市生态系统压力水平、约束水平、支撑水平等角度构建相应的定量研究指标体系，运用主成份分析法，提出了城市生态系统资源承载指数、环境约束指数以及综合承载指数。     

Interpreting seawater temperature range using oxygen isotopes and zooid size variation in Pentapora foliacea (Bryozoa)

This is the first investigation of how two independent proxies for seawater temperature inference (zooid size variation and oxygen isotope ratios of skeletal carbonate) relate to the actual measured ranges of temperature experienced by cheilostome bryozoan colonies. Nine specimens of the bimineralic marine cheilostome bryozoan Pentapora foliacea (Ellis and Solander, 1786) were analysed, collected from ~18-m depth at two localities in Wales, UK—four from Skomer Island (51°42′510″N, 5°13′42.60″W) and five from Porth Ysgaden, Lleyn Peninsula (52°54′6.75″N, 4°38′47.34″W). The annual range of temperature implied by zooid size variability provides a good approximation of the actual range of temperature recorded by a datalogger. However, annual ranges of temperature reconstructed from skeletal oxygen isotope ratios were narrower, typically not showing the lowest temperatures experienced by the colonies. This can be explained by progressive thickening of zooid skeletal walls during the life of the colony that homogenises the temperature signal by time-averaging over the lifetime of the colonies. Our study provides evidence that a combined morphological isotope approach has great potential in the reconstruction of annual ranges in seawater temperatures from historical and fossil bryozoans, particularly for species that lack ontogenetic skeletal wall thickening and bimineralic skeletal composition. As cheilostome bryozoans have been common in benthic communities since the Late Cretaceous, they represent a valuable and underutilised resource for the interpretation of environmental regimes.     

地理信息系统支持下的中国农业生产潜力研究

本文在地理信息系统的支持下,分析了全国671个气象台站的30年地面气象资料及地带性或大面积土壤的物化性质及养分状况资料,对影响生产潜力的光、温度、水分、土壤诸要素分别进行了分析、计算,尤其对土壤要素的处理进行了新的尝试,计算了我国的农业生产潜力。     

Climatology,Trend Analysis and Prediction of Sandstorms and their Associated Dustfall in China

Based on statistical data about Sand and Dust Storms (SDS) and their associated dustfall, features of temporal and spatialdistribution were studied first in this article. SDS and associateddustfalls occurred most often in northern China, especiallynorthwestern China. However, in the last two years, they have atendency to occur on the central and western parts of the Inner Mongolia Autonomous Region. As a result, Beijing is now among the impact areas, and the Chinese government is paying greaterattention to the matter. The changing trends of SDS and associated dustfalls were subsequently analyzed. Occurrences were seen to be decreasing with the feature of fluctuation duringthe period of 1954–2001, but they have slightly increased since 2000. Also, climate factors related to SDS and associated dustfalls were discussed. Finally, it was recommended that methods to predict SDS in China be further studied in the future.     

杭州湾海底管线溢油风险及应急措施

以杭州湾海底管线为例,提出海底输油管线穿孔溢油安全应急措施。海底输油管线穿孔后,利用抽油泵抽吸,使海底管线内产生负压,阻止管线内原油外溢,利用SCADA系统进行了模拟试验,结果显示：用抽油泵抽吸能使海底管线产生-0．038～-0．04MPa压力,理论上能将海水吸入,阻止原油外泄。     

非点源污染控制的现状及其立法原则

非点源污染危害规模大,防治困难,已经成为危害中国乃至全球生态环境的一个最重要因素。在管理与控制非点源污染方面,如果仅仅依靠技术层面上和经济层面上的治理,不仅治理难度大,投入成本高,而且在现有的技术条件下效果也不理想。因此,必须从政策法律的层面上来探讨非点源污染的控制。在现有的水污染立法体系中明确非点源污染的指导思想和立法原则,明确法律关系主体间的权利义务,使非点源污染控制有法可依。     

Coupling between free-surface fluctuations,velocity fluctuations and turbulent Reynolds stresses during the upstream propagation of positive surges,bores and compression waves

In open channel, canals and rivers, a rapid increase in flow depth will induce a positive surge, also called bore or compression wave. The positive surge is a translating hydraulic jump. Herein new experiments were conducted in a large-size rectangular channel to characterise the unsteady turbulent properties, including the coupling between free-surface and velocity fluctuations. Experiments were repeated 25 times and the data analyses yielded the instantaneous median and instantaneous fluctuations of free-surface elevation, velocities and turbulent Reynolds stresses. The passage of the surge front was associated with large free-surface fluctuations, comparable to those observed in stationary hydraulic jumps, coupled with large instantaneous velocity fluctuations. The bore propagation was associated with large turbulent Reynolds stresses and instantaneous shear stress fluctuations, during the passage of the surge. A broad range of shear stress levels was observed underneath the bore front, with the probability density of the tangential stresses distributed normally and the normal stresses distributed in a skewed single-mode fashion. Maxima in normal and tangential stresses were observed shortly after the passage of a breaking bore roller toe. The maximum Reynolds stresses occurred after the occurrence of the maximum free-surface fluctuations, and this time lag implied some interaction between the free-surface fluctuations and shear stress fluctuations beneath the surge front, and possibly some causal effect.     

微生物絮凝剂研究与应用进展

本文论述了微生物絮凝剂开发应用的必要性,介绍了微生物絮凝剂的种类和研究概况,分析了微生物絮凝剂的絮凝机理及其影响因素,列举了微生物絮凝剂的应用实例,认为今后微生物絮凝剂在环境污染治理中、特别是在回收废水中有益物质的过程中将占据重要地位。