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981.
南孚废电池对涡虫的急性毒性实验   总被引:1,自引:0,他引:1  
将在调节酸碱性前后的南孚废电池浸泡液分别配制成不同浓度梯度,对涡虫进行急性毒性实验,观察涡虫在各浓度浸泡液中的生存与摄食情况。结果表明浸泡液对涡虫生存及摄食的影响差异极显著(P〈0.01)。主要影响因素是电池的强碱性。  相似文献   
982.
IntroductionWiththeincreasingvarietiesandquantitiesofdyesenteringintotheenvironment,dyes,asanimportanttypeofpollutants,haveanadverseeffectonwater soil plantsystems ,accordingtosomeexperimentalresults(Cheng ,inpress) .IntheeasternChina ,industrialwastewaterf…  相似文献   
983.
马齿苋有性繁殖特性研究   总被引:1,自引:0,他引:1  
马齿苋有性繁殖特性研究结果表明,马齿苋的第1朵花在播种后44d开始开放,以后不断地形成花蕾和开花,并且边开花边结籽、种子成熟后即自行开裂、散落,这种特性给种子收集和生产大量用种带来许多困难,成为制约马齿苋规模化栽培的重要因子.因此,如何找到一套简单易行、操作方便、省时省力、能用于大量生产马齿苋种子的方法,是需要继续在生产实践中探索的问题.  相似文献   
984.
Abstract:  Geographically peripheral populations of widespread species are often the focus of conservation because they are locally rare within political jurisdictions. Yet the ecology and genetics of these populations are rarely evaluated in a broader geographic context. Most expectations concerning the ecology and evolution of peripheral populations derive from the abundant-center model, which predicts that peripheral populations should be less frequent, smaller, less dense, and have a lower reproductive rate than central populations. We tested these predictions and in doing so evaluated the conservation value of peripheral populations for the clonal shrub Vaccinium stamineum L. (Ericaceae, deerberry), which is listed as threatened in Canada. Based on 51 populations sampled from the center to the northern range limits over 2 years, population frequency and size declined toward the range limit, but ramet density increased. Sexual reproductive output varied widely among populations and between years, with many populations producing very few seeds, but did not decline toward range margins. In fact seed mass increased steadily toward range limit, and this was associated with faster germination and seedling growth, which may be adaptive in seasonal northern environments. Our results did not support the prediction that clonal reproduction is more prevalent in peripheral populations or that it contributed antagonistically to the wide variation in seed production. Peripheral populations of V. stamineum are as productive as central populations and may be locally adapted to northern environments. This emphasizes the importance of a broad geographical perspective for evaluating the ecology, evolution, and conservation of peripheral populations.  相似文献   
985.
钼和硼污染对大豆品质的影响   总被引:1,自引:0,他引:1  
以3个大豆(Glycine max)品种(浙春3号、浙春2号和3811)为材料,设置了4个钼、硼处理(适量钼和硼、高钼、高硼及高钼高硼同施),研究了钼污染和硼污染对大豆品质的影响.结果表明:高钼或高硼促使大豆种子蛋白质、维生素C、氮、磷、钾的含量显著减少,氨基酸的总量和必需氨基酸的总量大大降低,氨基酸各组分(除脯氨酸外)的含量都明显下降,脂肪的组分也发生变化,对种子中钙镁含量的影响不大,且高硼对大豆品质的毒害作用明显大于高钼.在过量条件下,钼和硼在大豆体内呈现相互抑制作用.3个大豆品种的品质问存在一定的基因型差异,3个品种对高钼和高硼的反应也存在差异.图2表3参18  相似文献   
986.
The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.  相似文献   
987.
The Salinas River watershed along the central coast of California, U.S.A., supports rapidly growing urban areas and intensive agricultural operations. The river drains to an estuarine National Wildlife Refuge and a National Marine Sanctuary. The occurrence, spatial patterns, sources and causesof aquatic toxicity in the watershed were investigated by sampling four sites in the main river and four sites in representative tributaries during 15 surveys between September1998 and January 2000. In 96 hr toxicity tests, significant Ceriodaphnia dubia mortality was observed in 11% of the mainriver samples, 87% of the samples from a channel draining anurban/agricultural watershed, 13% of the samples fromchannels conveying agricultural tile drain runoff, and in 100% of the samples from a channel conveying agricultural surface furrow runoff. In six of nine toxicity identificationevaluations (TIEs), the organophosphate pesticides diazinon and/or chlorpyrifos were implicated as causes of observed toxicity, and these compounds were the most probable causes oftoxicity in two of the other three TIEs. Every sample collectedin the watershed that exhibited greater than 50% C. dubia mortality (n = 31) had sufficient diazinon and/or chlorpyrifos concentrations to account for the observed effects.Results are interpreted with respect to potential effects on other ecologically important species.  相似文献   
988.
发光菌毒性试验在项目竣工环保验收监测中的应用   总被引:8,自引:1,他引:8  
某敏感化工技改项目曾因超标排污引发跨地区厂群纠纷被责令停产整改,为考察该项目整改后废水处理设施的运行效果,保障水生生物安全,在该项目竣工环境保护验收监测时,采用发光细菌毒性试验检测废水的急性毒性.结果表明,达标排放的废水对生物的急性毒性为低毒,试验结果与常规验收监测结果有可比性,发光细菌毒性试验可用于必须公示的敏感项目竣工环境保护验收监测.  相似文献   
989.
采用零价铁/过硫酸盐(Fe0/PS)高级氧化工艺降解水中有机染料铬黑T(EBT),考察了不同体系(PS、Fe0、Fe0/PS)、PS与Fe0物质的量之比、无机阴离子(NO3-,CO32-,Cl-)、溶液初始pH值、温度以及天然有机物对EBT降解的影响.结果表明,Fe0/PS工艺降解EBT符合准一级反应动力学模型(R2>0.87);和Fe0以及单独PS处理EBT相比,Fe0/PS能够高效降解水中的EBT,20min时EBT的去除率高达96.21%.PS/Fe0降解EBT的最佳物质的量之比为1:1.5.溶液中存在的NO3-,CO32-以及天然有机物均对EBT降解有不同程度的抑制作用.EBT的降解速率随溶液初始pH值的增加逐渐减小.随着温度的增加,EBT降解速率满足先增加后减小的规律,其反应活化能(Ea)为43.98kJ/mol.EBT在实际水体中的去除率仍能够保持较高的水平.使用GC-MS识别出10种中间产物,并据此提出反应路径.ECOSAR模型分析表明EBT降解产物中小分子有机物的生态毒性高于其大分子有机物.  相似文献   
990.
For this study, particulates or particulate matter (PM) and carbon monoxide (CO) levels were monitored at different sections on the production floor of a scrap metal recycling factory. A Met‐One GT331 dust monitor and A Toxi‐Rae gas monitor were used to measure PM and CO concentrations, respectively. The 24‐hr averaging period concentrations of particulate matter having diameters of 2.5 microns or less in diameter (PM2.5), particulate matter having diameters of 10 microns or less in diameter (PM10), and total suspended particulates (TSP) within the plant ranged between 8.3 and 50.4 μg/m3, 12.0 and 151.3 μg/m3, and 30.0 and 285.0 μg/m3, respectively, while the maximum 8‐hr concentration of CO within the plant was 20.5 parts per million (ppm). The United States’ Environmental Protection Agency (US EPA) limits for PM2.5, PM10, and CO were exceeded only in the area around the furnace. Nigeria's Federal Ministry of Environment (FMENV), the World Health Organization (WHO), and the World Bank statutory limit for TSP were also exceeded in the area around the furnace. Toxicity potentials (TP) of the investigated pollutants were greater than 1.0 around the furnace, indicating that work spaces in proximity to the furnace could expose workers to adverse health conditions.  相似文献   
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