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991.
秦皇岛近海养殖对潮间带微生物群落多样性的影响   总被引:1,自引:0,他引:1  
李佳霖  汪光义  秦松 《生态环境》2011,20(5):920-926
潮间带微生物群落在驱动海岸带生态系统物质循环和能量流动中具有重要作用,近海养殖造成的环境问题日益凸显,但其对潮间带微生物群落结构的影响还缺乏研究。采用变性梯度凝胶电泳(DGGE)和限制性片段长度多态性(RFLP)的分子生物学技术,研究秦皇岛养殖区与旅游区潮间带沉积物中微生物多样性的差异,分析养殖区微生物的16S rRNA基因文库的组成特征。结果表明:养殖区的微生物群落结构与旅游区形成较大的差异,DGGE图谱中养殖区的特有条带主要集中于γ-变形菌纲(γ-proteobacteria),还分布于α-变形菌纲(α-proteobacteria),拟杆菌门(Bacteroidetes),放线菌门(Actinobacteria)和厚壁菌门(Firmicutes)。影响潮间带微生物的群落结构的主要环境因子包括温度、盐度、pH和NO3-浓度,影响率达55.2%。对差异最大的洋河大桥南养殖区(Q1站)的微生物样品建立克隆文库分析群落结构,变形菌门(Proteobacteria)为优势菌群,占总群落的60%,其中γ-变形菌纲是主要存在的微生物纲,其余菌群包括放线菌门、拟杆菌门、蓝藻菌门(Cyanobacteria)和疣微菌门(Verrucomicrobia)的微生物。养殖区海岸带微生物群落中出现了与环境污染和赤潮密切相关的菌群,如拟杆菌门、肠杆菌属(Enterobacteriaceae)和α-变形细菌红细菌目(Roseovarius)的微生物。  相似文献   
992.
全氟辛烷磺酸对雄性鹌鹑生殖毒性影响   总被引:1,自引:1,他引:0  
以雄鹌鹑为禽类指示动物,探讨全氟辛烷磺酸(PFOS)对禽类的雄性生殖毒性,染毒组饲料中PFOS浓度分别为10和30mg·kg-1.雄鹌鹑从出生后第9天开始连续染毒54 d.实验结束时,观察睾丸和附睾脏器系数、精子数、睾丸组织中LDH和SDH酶活性、血清中甲状腺激素T3、T4和促甲状腺分泌激素(TSH)及睾酮(T)浓度,...  相似文献   
993.
Cu2+、Cd2+和Cr6+对斑马鱼联合毒性作用和生物预警的研究   总被引:3,自引:1,他引:2  
为了研究重金属对水生生物的联合毒性作用,以斑马鱼为受试生物,采用半静态法,在研究Cu2、Cd2和Cr6+对斑马鱼单一毒性的基础上,以获得的Cu2+、Cd2+和Cr6+的96 h-LC50数据,利用等效应曲线法研究了Cu-Cd、Cu-Cr和Cd-Cr的联合毒性作用,并综合分析环境毒理学指标的测定结果,考察利用斑马鱼作为水...  相似文献   
994.
Water quality information of Beijiang River, a tributary of Pearl River in Guangdong, China, was analyzed to provide an overview of the hydrochemical functioning of a major agricultural/rural area and an industrial/urban area. Eighteen water quality parameters were surveyed at 13 sites from 2005 to 2006 on a monthly basis. A bivariate correlation analysis was carried out to evaluate the regional correlations of the water quality parameters, while the principal component analysis (PCA) technique was used to extract the most influential variables for regional variations of river water quality. Six principal components were extracted in PCA which explained more than 78% and 84% of the total variance for agricultural/rural and industrial/urban areas, respectively. Physicochemical factor, organic pollution, sewage pollution, geogenic factor, agricultural nonpoint source pollution, and accumulated pesticide usage were identified as potential pollution sources for agricultural/rural area, whereas industrial wastewaters pollution, mineral pollution, geogenic factor, urban sewage pollution, chemical industrial pollution, and water traffic pollution were the latent pollution sources for industrial/urban area. A multivariate linear regression of absolute principal component scores (MLR-APCS) technique was used to estimate contributions of all identified pollution sources to each water quality parameter. High coefficients of determination of the regression equations suggested that the MLR-APCS model was applicable for estimation of sources of most water quality parameters in the Beijiang River Basin.  相似文献   
995.
996.
Fourteen surface water and nine surface sediment samples were collected from the Peacock River and analyzed for organochlorine pesticides (OCPs) by gas chromatograph?Celectron capture detector (GC-ECD). All the analyzed organochlorine pesticides, except o,p ??-DDT, were detected in sediments from the Peacock River; but in the water samples, only ??-HCH, HCB, p,p ??-DDD, and p,p ??-DDT were detected at some sites. The ranges for total OCPs in the water and sediments were from N.D. to 195 ng l???1 and from 1.36 to 24.60 ng g???1, respectively. The only existing HCH isomer in the water, ??-HCH, suggested that the contamination by HCHs could be attributed to erosion of the weathered agricultural soils containing HCHs compounds. Composition analyses showed that no technical HCH, technical DDT, technical chlordanes, endosulfans, and HCB had been recently used in this region. However, there was new input of ??-HCH (lindane) into the Peacock River. The most probable source was water flowing from Bosten Lake and/or agricultural tailing water that was returned directly into the Peacock River. DDT compounds in the sediments may be derived mainly from DDT-treated aged and weathered agricultural soils, the degradation condition was aerobic and the main product was DDE. HCB in the sediment might be due to the input from Bosten Lake and the lake may act as an atmospheric deposition zone. There was no significant correlation between the concentrations of OCPs (including ??HCH, ??DDT, chlordanes, endosulfans, HCB and total OCPs) and the content of fine particles (<63 ??m). The concentrations of OCPs were affected by salinity.  相似文献   
997.
The concentrations and chemical partitioning of heavy metals (Co, Cr, Ni, Zn, Cu, and Pb) in the marine near-shore sediment cores were investigated. Typically, the mean concentrations from Core B sediment samples were 98.6, 21.1, 47.0, 46.4, 107.6, and 31.9 mg kg???1 for Cr, Co, Ni, Cu, Zn, and Pb, respectively. The heavy metal concentrations were normalized to commonly used reference elements Al, Li, Sc, and total organic carbon. Based on Pearson coefficients, Li was found to be a good normalizer for Co (r?= 0.974), Cr (r?= 0.967), Ni (r?= 0.898), and Zn (r?= 0.929) in 80 sediment samples from three sampling sites. However, the correlation coefficients between Li and Cu, and Li and Pb were relatively low. Multivariate statistic approaches (Principal Component Analysis and Cluster Analysis) were adopted for data treatment, allowing the identification of two main factors controlling the heavy metal variability in the sediments. Heavy metals in the enrichment sections were evaluated by a sequential extraction method for possible chemical forms in sediments. The results showed that the residual, Fe/Mn oxides and Organic/sulfide fractions were dominant geochemical phases in the enriched sections, indicating low bioavailability of heavy metals in sediments.  相似文献   
998.
Based on an analysis of two methods for the modification of the F&EI for the DOW Guide, it is found that the effects of safety measures are not classified. Moreover, the efficiency of the measures is magnified to various degrees, as the positive impact of the loss reduction measures are applied to the rate reduction of the intrinsic hazard in the evaluated unit. For this reason, a modification method using classified safety measures is proposed, in which safety measures are classified into process protection measures and loss reduction measures. The calculation of the modified F&EI involves the credit factors of process protection measures, whereas the determination of the maximum probable property damage incorporates the loss reduction measures. This method could provide more reasonable reference data for hazard units because of its more objective and reasonable evaluation results.  相似文献   
999.
复杂系统事故成因的复杂性促使人们从系统科学和复杂性科学的角度来分析和处理复杂系统的安全问题.通过探讨复杂系统可靠性和安全性的关系,论证安全是复杂系统的整体涌现这一论题.通过分析系统安全涌现的内涵,提出用于度量复杂系统风险状态的风险熵理论,给出了复杂系统安全事故立体致因网络的构建方法,并提出了通过控制复杂致因网络上风险熵的动力学传播过程来控制复杂系统安全涌现的研究思路.研究结论对复杂系统安全问题的研究有推动作用.  相似文献   
1000.
信息流的畅通和数据资源的有效利用是信息化可持续发展的基础。本文介绍了基于顶层设计的数据资源规划方法,提出数据资源规划的工作步骤。结合宏观环境督察业务现状和业务发展需要,归纳、分析、聚类、抽象出宏观环境督察业务职能域和全域数据元素集,形成了宏观环境督察数据资源的整体规划,为建立宏观督察业务的业务模型和数据模型提供了基础。  相似文献   
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