喀斯特地区城镇化质量与土地利用系统健康协同演化关系研究

在城镇化过程中,城镇化质量与土地利用系统健康存在着相互联系、相互影响的耦合关系,只有当两者协调发展,才能进一步促进城镇化的协调发展。以喀斯特地区贵阳市为研究对象,在构建了城镇化质量和土地利用系统健康的评价指标体系后,分别计算了两者的综合指数,并采用耦合度模型与耦合协调模型以及剪刀差方法对两者的协调关系进行分析。研究表明：（1）城镇化质量和土地利用系统健康的综合〖JP+2〗指数大体上呈逐年上升的趋势,其中土地利用系统健康先后经历了从亚健康到初级健康再到中级健康的状态;（2）城镇化质量与土地利用系统健康的耦合度在研究期内一直处于拮抗水平,耦合协调水平先后经历了从濒临失调到勉强协调再到初级协调的状态;（3）城镇化质量与土地利用系统健康演化速率的剪刀差较为稳定,波动趋势比较平缓,贵阳市城镇化质量与土地利用系统健康这两个系统发展演化速率的差异基本维持在稳定水平。在未来应当采用促进城镇化质量与土地利用系统健康双向提升的优化路径以提高两个系统之间的耦合关系     

六六六(HCHs)在小白洋淀水生植物中的分布与富集

利用GC-ECD测定了小白洋淀6个采样点的9种浮水、挺水和沉水植物中4种六六六(hexachlorocyclohexanes,HCHs)异构体的含量,分析了其分布、组成及富集特征。结果表明:1)小白洋淀水生植物中总HCHs含量范围在ND~7.47 ng·g-1(ww),浮水植物中HCHs含量最高,挺水植物各组织含量也有明显差异,根部HCHs含量明显高于茎叶2种组织。2)4种HCHs异构体中,γ-HCH的残留水平要显著高于其他3种异构体。在沉水植物和浮水植物中,均以γ-HCH占绝对比例,相对含量达60%~99%;而在挺水植物中,δ-HCHs占有较高比例,并且主要富集在挺水植物的根部,茎中次之,叶中最少。3)小白洋淀浮水植物和沉水植物HCHs含量与水体中HCHs含量呈显著的正相关关系,而挺水植物荷花、蒲草中HCHs各组分含量与水体中HCHs的相关关系不显著。4)水生植物对水中HCHs的富集系数BCF在8.7~661.2范围;浮水植物的BCF最高,沉水植物次之,挺水植物的茎对水体中HCHs的BCF最低。     

Applicability of sustainable urban drainage systems: an evaluation by multi-criteria analysis

Urban flooding has become more serious and worldwide in recent years, especially in the big cities of developing countries. This study uses a multi-criteria analysis (MCA) approach to evaluate the applicability of sustainable urban drainage systems (SUDS), a flood control measure, in the central part of Ho Chi Minh City, Vietnam. The output of the personal computer storm water management model along with interviews with 140 households was used to assess the efficacy and acceptability of four SUDS alternatives: rainwater harvesting, green roof, urban green space and pervious pavement. On technical performance, green roof was the best alternative, followed by pervious pavement, urban green space and rainwater harvesting. Results of the social survey, however, diverged largely from the results of the technical assessments. In particular, people generally prefer public SUDS such as urban green space and pervious pavements to household solutions. With respect to the MCA, we applied four different procedures: Borda count, pair-wise voting, range of value and analytic hierarchy process. Despite some differences, the integrated results from MCA largely agree that urban green space is the most favourable type of SUDS, followed by green roof, pervious pavement and rainwater harvesting.     

Oxidation of Cyclic Ethers by Alkane‐Grown Mycobacterium vaccae JOB5

In this study we investigated the cometabolic oxidation of six cyclic ethers by alkane‐grown Mycobacterium vaccae JOB5. These ethers include, among others, tetrahydrofuran (THF), 1,4‐dioxane (14D), 1,3‐dioxolane (13DO), and tetrahydropyran (THP). Cells grown on propane, n‐butane, n‐pentane, isobutane, or isopentane oxidized all six ethers. Ether‐degrading activity was inhibited by acetylene in alkane‐grown cells and was largely absent from cells grown on dextrose‐containing media. Propane competitively inhibited THF oxidation. γ‐Butyrolactone (γBL) accumulated and was also further oxidized during THF oxidation by propane‐grown cells. In contrast, no products were detected during 14D oxidation. Propane‐grown cells also rapidly oxidized 3‐hydroxytertrahydrofuran and exhibited strong hemiacetal‐oxidizing activity in an assay following methyl formate production from mixtures of methanol and formaldehyde. These observations suggest γBL is likely generated during THF oxidation through further oxidation of 2‐hydroxytetrahydrofuran. Limited growth of strain JOB5 was supported by several cyclic ethers and the corresponding lactones and diols potentially derived from these compounds. However, strain JOB5 grew more readily on 4‐hydroxybutyrate, the product of γBL hydrolysis. The ability of strain JOB5 to productively assimilate THF‐derived metabolites during growth on n‐alkanes was examined in carbon‐limited batch cultures. Relative to C‐limited growth on n‐pentane alone, culture growth increased up to twofold in the presence of THF while no stimulation of growth was observed in comparable experiments conducted with n‐pentane and 14D. Our results are discussed in terms of their significance to our understanding of cyclic ether cometabolism and their potential impact on approaches for cyclic ether biodegradation in the environment. © 2013 Wiley Periodicals, Inc.     

新安江水库水环境主要问题及保护对策

新安江水库是钱塘江的重要水源,对保障钱塘江中下游的生态安全和水体功能起着举足轻重的作用。为阐明新安江水库在流域经济发展和人类活动的影响下水环境的主要问题及保护对策,促进饮用水安全保障及构建健康水域生态系统,本文对新安江水库历年的水环境指标、浮游生物群落结构及其变化及水域生态灾变事件资料进行了综合分析。目前新安江水库存在上游来水变差、局部水域藻类异常增殖、渔业生产不合理、营养程度加重等众多问题,但其突出问题是藻类生物量增长过快。新安江水库水环境保护工作要从关注水质向维持生态系统健康转变,并尽快开展生态保育工作,控制流域污染、降低藻类数量、减少藻类异常增殖影响、科学合理渔业生产是其下一步保护的关键。而关于新安江水库的研究,虽然有一定的研究基础和资料,但对水域生态系统缺乏系统认识。研究气候变化条件下新安江水库水域生态系统的结构和功能以及长期演变规律;水利调度导致水位调整对区域水动力学条件、营养物输送过程的影响及评价水利调度对水库重要环境因子和生态系统影响;渔业养殖对水环境的影响,特别是鲢、鳙鱼大水面积养殖对水库生态系统的影响应是今后新安江水库主要的研究领域和方向。     

堆码试验标准差异的探讨与应用

本文介绍GJB 2711-1996中方法 13、方法 14两种堆码试验方法的异同点,以及它们与现行国家标准GB/T 4857.3-2008及GB/T 4857.4-2008中两种堆码试验方法的比较,说明堆码试验方法在国军标与国标中的共同点和差异,以及堆码试验中需要关注的问题。     

3×300t转炉二次除尘系统扩容改造

针对宝钢一炼钢3×300t转炉二次烟气严重污染室内外环境的实际情况,在兼顾节能与减排的协同原则下,确定了对原转炉二次除尘系统的扩容改造方案。竣工投运后,取得了良好的环保、节能效果。     

Roles of Scholars in the Practice of Combating-Desertification: A Case Study in Northwest China

This study investigated the perceived importance of scholars’ participation in combating-desertification programs in northwest China and analyzed the underlying factors and mechanisms. Our results show that, while various experts, professors, and researchers have participated in combating-desertification programs, their actions were often not effective. Only those scholars who understood the local situations adequately had important and positive impacts. These scholars served as information brokers between the governments and other stakeholders, entrepreneurial activity organizers for farmers, governmental representatives, or advocators for local affairs themselves. They played indispensible roles in facilitating efforts in combating desertification. The study also identified key factors that led to the success of scholars’ participation in combating-desertification activities. Our findings have practical implications for improving the effectiveness of scholars’ participation in land restoration and environmental management.     

鄱阳湖典型湿地土壤有机质及氮素空间分布特征

通过对鄱阳湖三个典型湿地植物群落带土壤有机质和全氮的空间分布特征的研究,结果表明：有机质和全氮在湿地土壤中的垂直分布规律具有一致性,表层含量显著高于下层,40 cm以下土壤养分含量基本稳定。表层土壤有机质和全氮含量不同植物群落间存在差异,有机质变化趋势为：刚毛荸荠群落带＜南荻群落带＜灰化苔草群落带;氮素含量的变化趋势为：南荻群落带＞灰化苔草群落带＞刚毛荸荠群落带。土壤碳氮比相对较低（10～23）;植物对养分的吸收能力、植被生长特征、湿地生态水文过程等影响着有机质和氮素含量的空间分布。