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131.
部分硝基芳烃对鲤鱼的急性毒性及定量构效关系 总被引:4,自引:0,他引:4
本文报告了26个硝基芳烃大对鲤鱼的急性毒性,应用LSER法得出了相关关系显著的QSAR方程。化合物分子的本征体积是毒性的主要影响因素。硝基芳烃的毒性随着分子本征体积,αm和I值的增大而增大,随着βm值的增大而减小。 相似文献
132.
Roy M. Harrison Andrew R. Deacon Marcus R. Jones Robert S. Appleby 《Atmospheric environment (Oxford, England : 1994)》1997,31(24):4103-4117
Hourly average concentrations of PM10 and PM2.5 have been measured simultaneously at a site within Birmingham U.K. between October 1994 and October 1995. Comparison of PM10 and NOx data with two other sites in the same city shows comparable summer and winter mean concentrations and highly significant inter-site correlations for both hourly and daily mean data. Over a four-month period samples were also collected for chemical analysis of sulphate, nitrate, chloride, ammonium and elemental and organic carbon. Analysis of the data indicates a marked difference between summer and winter periods. In the winter months PM2.5 comprises about 80% of PM10 and is strongly correlated with NOx indicating the importance of road traffic as a source. In the summer months, coarse particles (PM10−PM2.5) account for almost 50% of PM10 and the influence of resuspended surface dusts and soils and of secondary particulate matter is evident. The chemical analysis data are also consistent with three sources dominating the PM10 composition: vehicle exhaust emissions, secondary ammonium salts and resuspended surface dusts. Coarse particles from resuspension showed a positive dependence on windspeed, whilst elemental carbon derived from road traffic exhibited a negative dependence. 相似文献
133.
以多溴联苯醚类化合物的ER亲合力为生物活性指标,运用基于配体结构信息的CoMFA/CoMSIA方法,模拟该类化合物与雌激素受体的结合作用机制,结果表明,这些结构类似化合物中存在的不同受体作用模式,需要结合基于受体功能区结构的QSAR方法进一步探讨。 相似文献
134.
为了研究南京市PM2.5的污染特征及来源贡献,于2018年3月至2019年2月在南京仙林地区进行PM2.5组分的在线监测,运用PMF和CMB受体模型,开展PM2.5的来源解析.结果表明,观测期间南京市PM2.5平均质量浓度为54.3μg/m3,其中冬季平均浓度76.4μg/m3.PM2.5的主要组分为NO3-(21.3%~30.8%)、SO42-(18.9%~23.5%)、NH4+(14.3%~16.2%).从全年平均来看,PMF模型得到的PM2.5解析结果为:二次无机气溶胶(54.9%)、燃煤源(17.4%)、二次有机气溶胶(7.4%)、机动车排放源(7.1%)、工业源(4.9%)、扬尘源(4.8%)、其他源(3.4%);CMB模型得到的PM2.5解析结果为:硝酸盐(33.0%)、硫酸盐(24.0%)、燃煤源(16.4%)、机动车排放源(8.4%)、二次有机气溶胶(7.1%)、扬尘源(5.7%)、其他源(2.9%)、工业源(2.4%).不同季节PM2.5来源有所差异,夏冬季二次无机气溶胶占比大于春秋季,春冬季燃煤占比最大,二次有机气溶胶在秋季占比最大.结合2017年南京市大气污染源排放清单,对二次气溶胶贡献进行再解析,得到南京仙林地区PM2.5主要贡献来自燃煤源(PMF:34.14%,CMB:33.82%),机动车排放源(PMF:27.33%,CMB:29.33%)以及工业源(PMF:26.76%,CMB:24.77%).可见,影响南京仙林地区PM2.5的污染源主要来自燃煤源、机动车排放源和工业源,基于在线组分监测、利用PMF和CMB模型得到的PM2.5源解析结果具有较好的一致性. 相似文献
135.
多环芳烃作为持久性高毒性的有机污染物,一直受到广泛关注。酶联免疫分析技术因特异性强、快速、便捷等优点而广泛使用。建立了芳香烃受体介导的类酶联免疫竞争方法(类ELISA),用于检测环境中多环芳烃类物质的含量。在实验室条件下,分别检测了5种多环芳烃萘、苊、菲、荧蒽和芘,同时比较与高效液相色谱法(HPLC)和气相色谱-质谱联用法(GC/MS)在灵敏度、准确性和重现性等标的差异。HPLC检出限为2.70~10.71 ng/mL;GC/MS的检出限为2.60~24.40 ng/mL;类ELISA的检出限在1.24~3.10ng/mL。HPLC的加标回收率为58.03%~106.69%;GC/MS的加标回收率为88.16%~154.83%;类ELISA的加标回收率为74.67%~121.84%。HPLC的变异系数为4.26~9.03;GC/MS的变异系数为1.44~5.82;类ELISA的变异系数为2.56~8.16。结果表明,类ELISA方法灵敏度较好,准确性较高;而GC/MS方法重现性较好,检测更为稳定。 相似文献
136.
Understanding what shape values (which ultimately shape human behavior) will help improve the effectiveness of conservation solutions that depend on public support. To contribute to this understanding, we investigated the influence of societal‐level changes, such as modernization, on values in a multilevel framework. We collected survey responses (n = 4183) to questionnaires mailed to a random selection of households within each county in Washington (U.S.A.) (response rate 32%). We used multilevel modeling to determine the relationship between modernization (e.g., county‐level urbanization, wealth, and education) and wildlife value orientations (values that shape thought about wildlife) while controlling for individual‐level sociodemographics. We then explored how values influence conservation support at different levels (e.g., individual and county) and how values explain conservation support in a case study of public responses to wolf (Canis lupis) recovery. We found positive associations between county‐level examples of modernization and mutualism (a wildlife value orientation that prioritizes the perceived needs of wildlife) independent of a respondent's sociodemographics, and negative associations between modernization and domination (a wildlife value orientation that prioritizes human needs). Our results suggest that context has an additive impact on one's values; certain locations exhibited domination values, whereas others exhibited a mix of value types. This finding is important because actions that restrict human interests to promote biodiversity were negatively associated with domination and positively associated with mutualism. In the wolf case study, mutualism was strongly correlated with less social conflict over wolf recovery in many, but not all, counties (e.g., Pearson's r correlation = 0.59 in one county and a nonsignificant correlation in another). Our findings suggest that modernization operates on values within a state with implications for biodiversity, but other factors in addition to values must be investigated to fully understand what leads to proconservation behavior. 相似文献
137.
138.
以碘化硫代乙酰胆碱为底物,二硫代二硝基苯甲酸为显色剂,采用分光光度法测定了21种有机磷农药对乙酰胆碱酯酶(AChE)的半抑制浓度(IC50).运用多元线性回归分析以及参数间的自相关分析建立有机磷农药对AChE抑制作用的QSAR模型.模型分析表明,有机磷农药对AChE的抑制作用主要受特定方向上的原子极化率及原子的电拓扑状态的影响,是多因素综合作用的结果.模型可解释高达78%的数据变异和显著的预测能力(q2=0.653),表明有机磷农药对AChE的抑制作用可借助结构活性关系模型进行预测与评价. 相似文献
139.
O. V. Bukharin N. V. Nemtseva S. V. Shabanov A. O. Plotnikov 《Russian Journal of Ecology》2001,32(2):94-97
Field and laboratory investigations were performed to study the distribution and functional significance of antilysozyme activity (ALA) in algal cultures. According to the results obtained, ALA as a trait is widespread among green and blue-green algae but is expressed to different extents. Experiments on the algae–zooplankters model showed that ALA is a factor facilitating the survival of algae in freshwater communities by promoting the establishment of their trophic and symbiotic relationships with other aquatic organisms. Analyzing the intrapopulation structure of algal cultures associated with zooplankters, it was shown that changes in the ALA of algal clones have adaptive significance, providing for a greater stability of algal populations in biocenoses. 相似文献
140.
A.H. El‐Sebae S.A. Soliman N.S. Ahmed A. Curley 《Journal of environmental science and health. Part. B》2013,48(4):465-474
Abstract Five organophosphorous insecticides: Leptophos, EPN, Cyano‐fenphos, trichloronate and salithion proved to cause irreversible ataxia not only to chicken but also to mice and sheep. TOCP was included as a reference. Cyanofenphos blocked the catecholamine B‐receptor binding activity with 3H‐norepinephrine at a level similar to that of the specific inhibitor propranolol in the mouse heart preparation. In the lamb heart preparation, the B‐receptor was more sensitive to Leptophos, salithion and TOCP than to propranolol. The six compounds and their oxons were screened for their in‐vitro inhibition to monamine oxidase (MAO), acetyl cholinesterase (AChE) and neurotoxic esterase (NTE) in the brain of either mouse, lamb or chicken. It is believed that their AChE inhibition stands for their acute toxicity, while NTE inhibition is responsible for their paralytic ataxia. 相似文献