典型抗生素二元混合物对明亮发光杆菌的急性联合毒性

以明亮发光杆菌作为受试生物,测定了不同类型抗生素的二元混合物对明亮发光杆菌的等比急性联合毒性.结果表明,4类抗生素对明亮发光杆菌二元等比急性联合毒性主要呈加和效应及拮抗效应.本研究可为水体中抗生素的联合生态风险评价和修复提供理论依据.     

营养盐浓度对中肋骨条藻优势种群富集多溴联苯醚的影响

以中肋骨条藻（Skeletonema costatum）和东海原甲藻（Prorocentrum donghaiense）组成中肋骨条藻优势种群的海洋微藻为研究对象,以我国近海水体中存在的3种丰度较高的多溴联苯醚同系物为代表,包括2,4,4＇-三溴联苯醚（BDE-28）、2,2’,4,4’-四溴联苯醚（BDE-47）和2,2＇,4,4＇,5-五溴联苯醚（BDE-99）,研究了硝酸盐浓度（0、128、512μmol·L-1）和磷酸盐浓度（0、8、32μmol·L-1）对中肋骨条藻优势种群生化成分和富集3种多溴联苯醚的影响,分析了中肋骨条藻优势种群对多溴联苯醚的富集量与生化成分的关系。结果表明,随着营养盐浓度的升高,单位藻细胞的富集量呈现降低趋势,硝酸盐浓度为0μmol·L-1时,3种多溴联苯醚同系物每106cells的富集量为3.93-5.01 ng,而硝酸盐浓度为512μmol·L-1时,每106cells富集量为3.53-3.94 ng,降低了10%-23%;不同硝酸盐浓度下单位体积藻液富集量差异较小,随硝酸盐浓度的升高,BDE-99和47富集量分别从0.180和0.179 ng·mL^-1降低到0.167和0.150 ng·mL^-1,BDE-28没有出现明显差异。与硝酸盐相似,多溴联苯醚单位藻细胞富集量也随着磷酸盐浓度的升高而呈现出降低的趋势,每106cells的富集量从磷为0μmol·L-1的3.04-3.28 ng降低到32μmol·L-1时的2.27-2.73 ng;不同磷酸盐浓度下单位体积藻液的富集量差异不显著,其中BDE-99富集量范围在0.188-0.190 ng·mL^-1,随磷酸盐浓度的升高,BDE-47和28富集量略有降低,从0.20 ng·mL^-1降低到约0.16 ng·mL^-1。中肋骨条藻优势种群单位细胞对多溴联苯醚富集随着营养盐浓度的增加而降低,其原因是营养盐浓度影响了其细胞生化成分,其中脂类含量与富集量存在正相关关系。对3种同系物富集量的比较发现,随多溴联苯醚同系物的Kow降低,富集量总体上呈现降低的趋势。     

冀东铁矿2种恢复模式植被演替过程中群落结构及生物多样性比较研究

油松（Pinus tabulaeformis）耐低温、干旱和贫瘠,是我国北方温性针叶林中分布最广的森林群落,也是我国北方广大地区最主要的本土造林树种之一,火炬（Rhus typhina Linn.）根萌蘖力强,耐寒、耐旱、耐盐碱,是一种适应周围环境能力极强的外来引入种树种。采用空间代替时间的方法,以冀东铁矿不同年份种植的人工火炬林和人工油松林群落为研究对象,采用样方法进行调查取样,分析了2种恢复模式不同演替阶段群落结构的变化,群落动态,同时采用Pielou均匀度指数、Margalef丰富度指数、Shannon-Wiener多样性指数分析了物种多样性在群落演替过程中的动态变化,在此基础上,对比分析了2种恢复模式在生态效益方面的优劣。主要结果如下：1）短期来看,火炬可以迅速提高植被盖度,增加生物量,但是,长期来看,随着火炬的快速萌集繁殖和林分的郁闭,林下草本急剧减少,形成火炬单优群落,而不能形成稳定的顶级群落。2）短期来看,油松生长缓慢,其生态效益远小于火炬群落,但是油松群落经过11年的演替形成了乔-灌-草3层结构,群落结构逐渐完善。3）演替初期火炬群落优势种以猪毛蒿（Artemisia scoparia）、狗尾草（Setaria viridis）等耐干旱的植物为主,演替后期林下物种迅速减少以至大量消失;油松群落经过11年的恢复,群落草本层植物种数逐渐增大,从一年生先锋植物占优势过渡到以白羊草（Bothriochloa ischaemun）和硬质早熟禾（Poa sphondylodes）为建群种,并出现了黄刺玫（Rosa xanthina）和胡枝子（Lespedeza bicolor）等多年生灌木。4）演替初期Margalef丰富度指数、Pielou均匀度指数和Shannon-Wiener指数表现为：火炬群落﹥油松群落,演替后期则相反,这主要是由群落内种间竞争关系和水热环境的差异造成。4）综合植物群落盖度、物种多样性和群落未来的演替趋势,火炬长期的生态效益远不及油松树种。     

基于模型预测的喹乙醇生态风险评估

兽药和饲料添加剂在养殖业的大量使用,使其成为造成生态环境污染和人体健康损害的一个重要因素.发达国家已经开始采用生态风险评估技术对兽药进行有效的环境管理,而我国在兽药的环境风险管理方面依然处于盲区.喹乙醇是我国畜禽和水产养殖中应用最广泛的一种兽药添加剂.采用欧盟经典的兽药生态风险评估模型与方法,对其进行生态风险评估.结果显示,喹乙醇在土壤、地表水、地下水中的预测暴露浓度分别为0.313～2.68 mg·kg-1、0.928～10.2mg· L-1和0.281 ～3.10 mg·L-1,预测无效应浓度分别为＞200 mg·kg-1、0.5 mg·L-1和0.5 mg·L-1,预测生态风险分别为＜ 1.34×10-2、1.856～20.4和0.562 ～ 6.20.可见,对于喹乙醇的风险管理要将重点放在降低其水生生态风险上.因此,兽药的生态风险评估技术可以为兽药的环境管理提供有效的技术支持.     

连云港潮滩表层沉积物中有机氯农药残留特征与风险评估

利用GC-ECD检测了连云港地区绣针河口、临洪河口、灌河口北和灌河口南等4个潮滩断面表层沉积物中DDTs和HCHs含量及组成成分.结果表明,连云港潮滩沉积物中有机氯农药的含量在2.15—24.84 ng.g-1之间,均值为9.09 ng.g-1.其中DDTs的含量在1.11—11.74 ng.g-1之间,均值为3.72 ng.g-1,HCHs的含量在0.38—20.17 ng.g-1之间,均值为5.36 ng.g-1.4个断面有机氯农药含量的顺序是临洪河口>绣针河口>灌河口北>灌河口南.连云港潮滩沉积物中HCHs主要来源于早期林丹在土壤中的残留,灌河口有新的DDT污染源输入.总有机碳是影响绣针河口和临洪河口潮滩有机氯农药分布的主要因素.以风险低值(ERL)为评价基准,沉积物中有机氯农药的最大风险商达到7.43,连云港潮滩有机氯农药存在着一定的潜在生态风险.     

Low levels of global genetic differentiation and population expansion in the deep-sea teleost <Emphasis Type="Italic">Hoplostethus atlanticus</Emphasis> revealed by mitochondrial DNA sequences

The orange roughy Hoplostethus atlanticus is a well-known commercial species with a global distribution. There is no consensus about levels of connectivity among populations despite a range of techniques having been applied. We used cytochrome c oxidase subunit I (COI) and cytochrome b sequences to study genetic connectivity at a global scale. Pairwise Φ_ST analyses revealed a lack of significant differentiation among samples from New Zealand, Australia, Namibia, and Chile. However, low but significant differentiation (Φ_ST = 0.02–0.13, P < 0.05) was found between two Northeast Atlantic sites and all the other sites with COI. AMOVA and the haplotype genealogy confirmed these results. The prevalent lack of genetic differentiation is probably due to active adult dispersal under the stepping-stone model. Demographic analyses suggested the occurrence of two expansion events during the Pleistocene period.     

Landscape-level influences of terrestrial snake occupancy within the southeastern United States

Habitat loss and degradation are thought to be the primary drivers of species extirpations, but for many species we have little information regarding specific habitats that influence occupancy. Snakes are of conservation concern throughout North America, but effective management and conservation are hindered by a lack of basic natural history information and the small number of large-scale studies designed to assess general population trends. To address this information gap, we compiled detection/nondetection data for 13 large terrestrial species from 449 traps located across the southeastern United States, and we characterized the land cover surrounding each trap at multiple spatial scales (250-, 500-, and 1000-m buffers). We used occupancy modeling, while accounting for heterogeneity in detection probability, to identify habitat variables that were influential in determining the presence of a particular species. We evaluated 12 competing models for each species, representing various hypotheses pertaining to important habitat features for terrestrial snakes. Overall, considerable interspecific variation existed in important habitat variables and relevant spatial scales. For example, kingsnakes (Lampropeltis getula) were negatively associated with evergreen forests, whereas Louisiana pinesnake (Pituophis ruthveni) occupancy increased with increasing coverage of this forest type. Some species were positively associated with grassland and scrub/shrub (e.g., Slowinski's cornsnake, Elaphe slowinskii) whereas others, (e.g., copperhead, Agkistrodon contortrix, and eastern diamond-backed rattlesnake, Crotalus adamanteus) were positively associated with forested habitats. Although the species that we studied may persist in varied landscapes other than those we identified as important, our data were collected in relatively undeveloped areas. Thus, our findings may be relevant when generating conservation plans or restoration goals. Maintaining or restoring landscapes that are most consistent with the ancestral habitat preferences of terrestrial snake assemblages will require a diverse habitat matrix over large spatial scales.     

How should regional biodiversity be monitored?

We consider quantification of biodiversity in the context of targets set by the Convention on Biological Diversity. Implicit in such targets is a requirement to monitor biodiversity at a regional level. Few monitoring schemes are designed with these targets in mind. Monitored sites are typically not selected to be representative of a wider region, and measures of biodiversity are often biased by a failure to account for varying detectability among species and across time. Precision is often not adequately quantified. We review methods for quantifying the biodiversity of regions, consider issues that should be addressed in designing and evaluating a regional monitoring scheme, and offer a practical guide to what types of survey are appropriate for addressing different objectives for biodiversity monitoring.     

有机肥中4类典型兽药抗生素的多残留测定

建立了固相萃取-超高效液相色谱-串联质谱（SPE—UPLC—MS／MS）法同时测定有机肥中7种磺胺类、4种氟喹诺酮类、4种四环素类和3种大环内酯类抗生素残留的方法。采用乙腈和磷酸盐缓冲液（pH=3）的混合液作为有机肥样品的提取溶液,用强阴离子交换柱（SAX）-亲水亲脂平衡萃取柱（HLB）串联进行提取液的富集和纯化。以甲醇-φ=0．1％的甲酸溶液作为流动相,进行液相质谱分析。18种抗生素在5—500μg·kg-1的浓度范围内线性关系良好,决定系数（r2）1〉0．99。以3倍信噪比估算磺胺类、氟喹诺酮类、四环素类和大环内酯类的检测限分别为0．37～4．65、0．43—2．42、0．94～2．78和0．83～4．20μg·kg-1,这4类抗生素50和500μg·kg。2个添加水平的样品平均加标回收率分别为71．6％～94．3％、72．3％～86．7％、71．0％～102．2％和70．7％～93．3％,相对标准偏差在2．1％～11．4％之间。采用所建方法对南京地区市售8种有机肥中18种抗生素含量的测定结果显示,除磺胺类外,其他抗生素均有不同程度的检出。     

烧结机分导式半干法脱硫技术研究

介绍了烧结烟气的特性,列举了目前烧结脱硫存在的主要问题,并对常用的烧结脱硫技术进行分析。提出一种经济性更好的烧结机分导式半干法脱硫技术。