正常工况下石油类污染物在非饱和带中的运移特征分析

石油的战略储备对国家安全和经济的持续健康发展有着积极意义,但储备中的滴、漏等现象不可避免地将对地下水造成污染．本文以兰州某拟建石油储备库为例,模拟研究石油类污染物在非饱和带中的运移特征,结论认为在正常工况下,石油类污染物在非饱和带运移特征为：污染物浓度随着时间推移逐渐增加,在50年左右土层达到饱和,将对地下水造成严重污染．图4,参3．     

Plant polyphenols – implications of different sampling,storage and sample processing in biodiversity-ecosystem functioning experiments

Plant polyphenols are involved in important ecosystem processes and may affect nutrient cycling. Previous investigations have demonstrated detrimental effects of suboptimal sample treatment on the quantity of extractable plant polyphenols. We compared leaf polyphenol concentrations of 20 tree species from East China in two sample sets collected under different conditions: (a) according to established protocols and stored more than three years, (b) under conditions optimised for leaf polyphenols. We investigated the variance brought about by suboptimal sample handling as compared to the variance caused by the taxonomic range of species. Family-affiliation explained the largest proportion of variance, whereas sample handling had only minor effects. Reducing the taxonomic range increased the impact of differences in sample handling. Additionally, we showed that the concentrations of leaf polyphenols were phylogenetically more conserved than other leaf traits. Non-metric-multi-dimensional scaling revealed similar ordination patterns for leaf polyphenol concentrations in both sample sets with both ordinations being closely correlated. Finally, we computed separate ordinations including an extended set of leaf traits and found that both analyses led to similar ecological conclusions. Consequently, in studies comprising a wide taxonomic range, the adverse effects of suboptimal sample handling may be overridden by the variation brought about by phylogeny.     

一株反硝化菌的脱氮性能

从广州市某污水处理厂缺氧段活性污泥中分离筛选出一株反硝化菌,以该菌株为研究对象,鉴定后对该菌株进行脱氮条件最优化实验,在此基础上,分析其厌氧氨氧化能力。结果表明：在柠檬酸钠浓度为9 g·L-1,KNO3浓度为1 g·L-1,温度为35℃,pH为6.8的条件下,同时控制接种量为2.5%,即控制初始菌株浓度为107 mL-1时,2 d后8号菌能达到87%的最佳NO3--N去除率;在厌氧氨氧化能力检测实验中,培养液中生化反应以反硝化作用为主,在第3~5天发现厌氧氨氧化反应,因此推测这株菌具有厌氧氨氧化反应能力。经初步鉴定,该菌株为苏云金芽孢杆菌（Bacillus thuringiensis）。     

公路货运瓶颈节点污染物时空分布特征分析

研究公路货运瓶颈节点的污染物形成机理与分布特征可为货运高排区域的大气污染联防联控提供理论依据.通过采集北京市重点货运路网的逐秒行驶轨迹数据、重型柴油车排放测试数据,依据拥堵形成消散机理,设计基于行驶工况(减速、加速、怠速)的排放源强量化指标,进而构建货车拥堵时空排放模型.最后,以北京市通州区西集综合检查站为案例,分析该瓶颈节点的CO2、CO、THC、NOx时空分布特征,并对比设站前后以及采取减排措施下时空污染物变化情况.结果表明:瓶颈节点的排放总量是常规的2.2～2.5倍.瓶颈区前排队区域以及驶离线后0～10m区域排放强度最大,为减速驶入和瓶颈作业区域的2.1～2.9倍.抽检与提升检测站服务效率均在一定程度上改善了排放,且2种减排措施对NOx改善效果最为显著.     

贫燃条件下汽车尾气净化催化剂的研究

综述了目前国际上由低碳烃催化还原ＮＯｘ催化剂的研究现状，分析了金属氧化物催化剂、贵金属催化剂、分子筛催化剂以及双功能催化剂各自的优势和存在的问题。对失活原因以及反应机理作了简单概述，最后提出展望。     

混凝-微滤膜组合净水工艺中膜过滤特性及其影响因素

采用混凝-微滤膜组合工艺处理微污染原水,间歇抽吸的运行方式连续运行,考察了膜组件的抽吸时间,抽/停时间比和曝气量对膜过滤性能的影响.采用膜通透性J/p作为膜过滤性能的评价指标.结果表明,在各操作条件下,膜通透性J/p由于膜污染的发生均先快速降低,随后随时间缓慢下降.但J/p的初期下降速度和缓慢下降阶段的相对稳定值因操作条件的不同而不同.抽吸时间对膜通透性影响较大,其次为抽/停时间比.在一定的条件下,抽吸时间缩短1/2,产水率可提高2倍;抽/停时间比缩短,产水率可提高50%.当抽吸时间和抽/停时间比分别为15min和3.8时,J/p值较高.曝气量在一定范围内的增加有利于提高膜通透性.本试验中,曝气量由2m³/h增加至4m³/h时,膜通透性可提高约15%,但当曝气量增加到6m3/h时,膜通透性并无显著改善.膜面污染物分析表明,在本研究使用的原水条件下,Si和Ca是主要的无机污染元素.     

Morphological-anatomical features of underground organs in some higher plant species in relation to their adaptation to ecological conditions

In seven higher plant species of different taxa, structural features of underground organs have been considered, and the levels of intraspecific variation in some characters of these organs have been determined. Different pathways of the structural adaptation of these species to the environment are demonstrated on the morphological and anatomical levels.Translated from Ekologiya, No. 2, 2005, pp. 97–105.Original Russian Text Copyright © 2005 by Tarshis.     

Using diatoms to assess the impacts of prehistoric, pre-industrial and modern land-use on Danish lakes

The impact of contemporary agriculture on Danish lakes is acknowledged to be extreme. In particular, high loading of nutrients from agricultural soils contributes to the eutrophic conditions found in many of Denmark’s lakes. Palaeolimnological studies have shown that human disturbance of the Danish landscape since the introduction of agriculture around 6,000 years ago has had a major impact on lake ecosystems. The European Union’s Water Framework Directive requires an evaluation of reference conditions for lakes, the conditions expected with only minimal human impact. Monitoring data and palaeolimnological studies of Danish lakes demonstrate that many of the most detrimental effects of eutrophication have been experienced in recent decades. A new study has suggested that the reference status for Danish lakes may be set to the status in ad 1850–1900, probably providing attainable, realistic restoration targets for many sites. The aims of this study were to explore the impacts of past and contemporary land-use on Danish lakes, and to consider how appropriate the use of 1850 as a date to define reference status is for these sites. Catchment land-cover data for ad 1800, taken from historical maps, and sedimentary diatom assemblages of the same age, from dated sediment cores, were used to assess the impact of pre-industrial land-use on 20 Danish lakes. Analysis of contemporary land-cover data and surface-sediment diatom assemblages for the 20 sites was also made. In-lake total phosphorus (TP) concentrations were estimated using the sedimentary diatom assemblages and an existing calibration dataset for Danish lakes. The percentage of the lake catchment that was agricultural land in ad 1800 explained 8.8% of the total variation in the diatom data. The land-cover variables ‘built-up areas’ and ‘plantations’, together explained 16.9% of the variation in the diatom data for the modern samples. Diatom-inferred TP concentrations were high for both ad 1800 (mean 112 μg TP L⁻¹) and the present (mean 122 μg TP L⁻¹), the latter estimates reflecting efforts in recent decades to reduce nutrient loading to Danish lakes following very high levels of nutrient enrichment post-1950. The data presented highlight the impact that human activities 200 years ago, particularly agriculture, had on Danish lake systems. The long cultural history and major anthropogenic disturbance of the Danish landscape mean that true reference conditions for lakes (or ‘baseline’ conditions, those found prior to human impacts) can be found only by considering century to millennial timescales.     

武汉—九江城市集聚带发展与长江经济带中段开发

简要分析了长江经济带中段武汉———九江城市集聚带发展的区位优势条件，带内城市体系结构和城市经济特征、探讨了带区城发展所特有的文化底蕴，提出了为推动城市集聚带及长江中游经济发展应首先解决的构筑城市地域空间新格局的设想。