人工复合生态系统对太湖局部水域水质的净化作用

根据不同生态类型水生高等植物的净化能力及其微生境特点,设计建造了由漂浮、浮叶、沉水植物及其根际微生物等组成的人工复合生态系统（artificialcomplexecosystem;AcE）,并在太湖五里湖中桥湖湾内以动态模拟试验,从群落水平研究了多种水生植物镶嵌组合的人工复合生态系统对富营养化湖水的净化能力。结果表明,富营养化湖水经该系统净化后,藻类生物量（以Chla计）下降58％,氨氮下降66％,总氮下降60％,总磷下降72％,可溶性磷酸盐下降80％,水质得到明显改善。与以该湖湾湖水为水源的水厂出水相比,人工复合生态系统出水的氨氮比水厂出水的氨氮平均低45％,总氮低37％,可见经人工复合生态系统处理的湖水部分指标优于同源的自来水。     

Tributyltin chloride disrupts aortic vascular reactivity and increases reactive oxygen species production in female rats

Environmental Science and Pollution Research - Organotin compounds, such as tributyltin (TBT), are environment contaminants that induce bioaccumulation and have potential toxic effects on marine...     

生物扰动作用对河口沉积物中荧蒽去除的影响

通过室内微宇宙实验系统研究了天津厚蟹(Helice tientsinensis)和双齿围沙蚕(Perinereis aibuhitensis)生物扰动作用下河口沉积物中荧蒽的去除情况。实验结果显示,天津厚蟹扰动组中荧蒽的去除率显著高于沙蚕扰动组(P=0.05)和对照组(P=0.003),其中对表层(0~2 cm)和中层(3~5 cm)的促进效果最为显著;虽然各实验组表层沉积物中荧蒽的去除率均超过50%,但扰动组的去除更快,在36 d时就达最高去除率68%;双齿围沙蚕扰动组底层沉积物中荧蒽的去除率高于厚蟹扰动组和对照组,但差异不显著。研究表明表层沉积物中的荧蒽易去除,厚蟹生物扰动对荧蒽去除有显著促进作用;在距离表层5cm以下的沉积物中荧蒽的持久性增强,但生物扰动作用可促进其去除。     

青海湖湟鱼(Gymnocypris przewalskii)中PCBs和PCDD/Fs的分析

应用同位素稀释高分辨气相色谱/高分辨质谱(HRGC/HRMS)分析了青海湖湟鱼体内多氯联苯(PCBs)和二噁英(PCDD/Fs)的含量.发现7-9年龄段湟鱼体内平均PCBs总浓度高达3484.9pg·g-1 ww,PCBs的毒性当量为0.41-0.57pgWHO-TEQ·g-1ww.除了PCB-81以外,其它11种二噁英类PCB都被检出,7种具有指示作用的PCB同系物(PCB-28,52,101,138,153,180)的浓度含量占总PCBs浓度的26%.湟鱼体内二噁英基本上未检出.由于青海湖区基本上没有工业污染源,鱼体内的PCBs可能是长距离迁移沉降和生物富集的结果.     

Invasive species change detection using artificial neural networks and CASI hyperspectral imagery

For monitoring and controlling the extent and intensity of an invasive species, a direct multi-date image classification method was applied in invasive species (salt cedar) change detection in the study area of Lovelock, Nevada. With multidate Compact Airborne Spectrographic Imager (CASI) hyperspectral data sets, two types of hyperspectral CASI input data and two classifiers have been examined and compared for mapping and monitoring the salt cedar change. The two types of input data are all two-date original CASI bands and 12 principal component images (PCs) derived from the two-date CASI images. The two classifiers are an artificial neural network (ANN) and linear discriminant analysis (LDA). The experimental results indicate that (1) the direct multitemporal image classification method applied in land cover change detection is feasible either with original CASI bands or PCs, but a better accuracy was obtained from the CASI PCA transformed data; (2) with the same inputs of 12 PCs, the ANN outperforms the LDA due to the ANN’s non-linear property and ability of handling data without a prerequisite of a certain distribution of the analysis data.     

自生生物动态膜反应器处理低碳氮比污水的研究

在好氧连续曝气方式下采用自生生物动态膜反应器处理低C/N污水,水力停留时间为5 h,膜通量为17～19 L/(m2·h) ,COD/ NH 4-N 在0.56～2.22,COD去除率在起始阶段达70%左右,运行稳定后,下降到40%左右; NH 4-N 的去除率一直稳定在 60.0% 左右.在 NH 4-N 的氧化过程中, NH 4-N 除被生物利用外,大部分被转化为 NO-2-N (出水中 NO-3-N 浓度非常低),亚硝化率平均达到94%.     

DX—100型离子色谱仪用于冰雪样品中阴,阳离子的测定

本文介绍了ＤＸ－１００型离子色谱仪用于冰雪样品中阴,阳离子的测定,以东北五大连池地区白龙洞和水晶宫为例,介绍了阴,阳离子测定在分析化学物质来源和成冰过程中的重要作用。     

大地震诱发滑坡的分布特点及危险性区划研究

汶川8.0级大地震诱发大规模以滑坡、崩塌为主的地质灾害,改变了原有的地貌形态,形成多处堰塞湖,毁坏民房和道路,使之成为严重的次生滑坡灾害危险区域.以成都市的都江堰、彭州、崇州、邛崃、大邑5个市、县地震区为研究区,分析了滑坡分布与地震烈度和宏观震中距关系,并在GIS技术的支持下采用贡献权重迭加法进行了滑坡危险性区划,分别获得研究区不同等级的危险区面积和滑坡分布密度,其中彭州、都江堰成为地震滑坡最严重的区域.     

Changes in pH,dissolved organic matter and Cd species in the rhizosphere soils of Cd phytostabilizer Athyrium wardii (Hook.) Makino involved in Cd tolerance and accumulation

Phytostabilization has great practical significance and flexibility in the ecological restoration of mining tailings and remediation of heavy metals polluted soils. However, potential use of metallophytes in phytostabilization is limited by a lack of knowledge of many basic plant processes. A mining ecotype (ME) Athyrium wardii, Pb/Cd phytostabilizer, and a non-mining ecotype (NME) A. wardii were grown in a pot experiment to investigate the chemical characteristics of the rhizosphere when exposed to the Cd polluted soils. Rhizobags were used to collect rhizosphere and bulk soils, separately. The results indicated that the ME A. wardii was more efficient in Cd accumulation in the root than NME after growing in Cd polluted soils for 50 days in a green house. Soil solution pH and dissolved organic carbon (DOC) concentration in the rhizosphere of ME A. wardii were higher than in the bulk soil and initial values (before planting), whereas the increment in the ME A. wardii were greater than NME. Owing to the increasing of rhizosphere soil pH, exchangeable Cd significantly decreased, whereas the other Cd species were increased with increasing soil DOC values. It is assumed that the ME A. wardii was effective in stabilizing Cd from the mobile fraction to non-mobile fractions. Results from this study suggest that rhizosphere alkalinization and the exudation of high amounts of dissolved organic matter (DOM) to reduce heavy metal mobility might be the two important mechanisms involved in the metal tolerance/accumulation of ME A. wardii.