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1.
介绍了上海市世博环境空气质量集合数值预报系统的框架,分析了各模式在上海市空气质量预报及排放源污染贡献测算中的应用情况,提出开发多种预报手段、实施集合预报是提高城市空气质量预报准确率的发展方向。  相似文献
2.
长江下游沉积物中重金属污染现状与特征   总被引:16,自引:9,他引:7       下载免费PDF全文
对长江下游沉积物中的重金属Co、Cr、Cu、Ni、Pb、Zn、Mn、Hg和As进行全量和醋酸提取态(包括水溶态、可交换态和碳酸盐结合态)分析.结果表明,大部分重金属主要来源于地壳元素的自然释放,但Cu、Zn、Hg和As在最近十几年因受到人为排放的影响质量比有所增加.长江江苏段的重金属质量比普遍高于入海口上海段;位于悬浮物易沉降地区的靖江重金属质量比明显偏高.Cu和Zn总体质量比较高,且醋酸提取态所占比例较大,对长江下游存在潜在的生态风险.  相似文献
3.
The study was carried out to assess the levels of pesticide residues in the water of Meiliangwan Bay, Taihu Lake of China. The most commonly employed organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs) and herbicide atrazine were analyzed. The water samples were collected seasonally from Meiliangwan Bay within a period of one year. The pesticides were analyzed by gas chromatography (GC) with μECD or NPD after solid-phase extraction (SPE), which was confirmed by GC with an ion trap mass spectrometry (MS). The mean concentrations were 1.98 ng/l for lindane, 0.378 ng/l for heptachlor epoxide, 0.367 ng/l for p,p′-DDE, 0.496 ng/l for p,p′-DDD, 1.06 ng/l for p,p′-DDT and 51.6 ng/l for dichlorvos, 39.0 ng/l for demeton, 346 ng/l for dimethoate, 4.12 ng/l for methyl parathion, 11.6 ng/l for malathion, 2.17 ng/l for parathion and 217 ng/l for atrazine. Generally, low concentrations of OCP were found, whereas the concentrations of the OPPs and atrazine in the water of Taihu Lake were relatively high. Heptachlor epoxide and lindane were the two most commonly encountered OCPs while dichlorvos, demeton and dimethoate were found to have much higher concentrations and occurrences than other OPPs.  相似文献
4.
乙醇法测定浮游植物叶绿素a含量的讨论   总被引:6,自引:0,他引:6  
采用热乙醇法以及乙醇冷冻提取法测定浮游植物叶绿素a含量,以比较两种方法的效果.实验结果表明,两种方法的测定值之间有较好的线性相关关系.热乙醇法快速高效,可以替代国内使用较多的乙醇冷冻提取法.  相似文献
5.
中国环境风险预警现状及发展趋势   总被引:5,自引:0,他引:5       下载免费PDF全文
伴随着社会经济的快速发展,中国所面临的环境风险压力也逐渐增大。预警是科学判定环境风险变化、提升环境应急响应水平和规避环境风险的有力手段。在查阅国内外文献的基础上,从预警指标体系、预警模型、预警系统及平台、预警仪器设备四方面阐述了中国环境风险预警的现状;结合国内外动态和环境预警的实际需求,分析了环境风险预警的发展趋势。  相似文献
6.
沉积物中多氯联苯分析的纯化条件优化研究   总被引:4,自引:3,他引:1       下载免费PDF全文
比较了各种填料层析柱和洗脱液的差别,并根据有机溶剂使用量较少的样品纯化方案,建立了适用低有机质含量水体表层沉积物中不同极性多氯联苯(PCBs)的分析方法.结果表明,该方法检测限在0.11 ng/g~0.35 ng/g(干重)之间,对主要多氯联苯同族体的回收率是77.9%~112.1%.用该法分析了长江中下游水体表层沉积物中的PCBs,质控结果表明,该纯化方法的效果理想.  相似文献
7.
环境样品中铅、锑、汞、硒形态分析研究进展   总被引:3,自引:2,他引:1       下载免费PDF全文
综述了环境样品中铅、锑、汞、硒形态分析的研究进展,以及光谱法、色谱法、毛细管电泳及其联用技术在形态分析中的应用,展望了环境样品痕量元素形态分析的发展前景。  相似文献
8.
Changzhou is a typical waterside municipality with approximately 2,500 years of history located south of the Yangtze River. It was an agriculturally oriented region but is becoming an industrialized region. Rural green landscaping in this region possesses characteristics of traditional Chinese gardens. This paper presents a methodology for assessing the visual quality of green landscaping in rural residential areas through public perception-based and expert/design approaches. The former approach enables us to rank green landscaping based on a survey of public preference; the latter weighs the contributions of the attributes contained in a photograph to its overall scenic beauty via correlation, regression, and factor analyses. The photographs used in the survey included road greenways, riparian greenways, residential public gardens and green landscaping around houses, with each type of landscape represented by seven photographs. In total, 141 college students and 41 other participants ranked photographs of each landscaping type from highest to lowest preference. The results indicate that the preferences of students are similar to those of the general public. Examples of green landscaping depicted in the “best” four photographs possessed more attractive qualities regarding the variety of vegetation, richness of colors and a selection of human additions compared to those depicted in the “worst” photographs. The perceived visual quality was positively influenced by, in decreasing order of importance, the variety of vegetation, color contrast, the openness of green spaces, the area of vegetation, and positive man-made elements; conversely, it was negatively influenced by the type of topography. Moreover, some suggestions were offered for future rural greening regarding perceived visual beauty.  相似文献
9.
毒死蜱生态毒理与风险研究综述   总被引:2,自引:0,他引:2       下载免费PDF全文
毒死蜱被认为是一种高效、安全和广谱的含氮杂环类杀虫杀螨剂,被广泛应用于农业生产病虫害的防治中。在中国,毒死蜱曾被列为取代高毒农药的重要品种,并被农业部推荐用于无公害农产品生产的专用杀虫杀螨剂。近年来,由于不断发现的毒死蜱生物毒性及其产生的环境安全问题,美国和欧盟国家已经在某些范围内禁用毒死蜱。综合近几年文献,从环境介质含量、转化行为、生物活性检测以及国外水质基准等方面,对其分别叙述,旨在为今后中国地区毒死蜱的环境健康风险评价、生态风险评价和水质基准制定提供基本参考依据。  相似文献
10.
通过测定沉积物和土壤中cd、Pb、cr、zn、cu、Ni6种重金属元素的平均含量,计算其富集因子,分析长江南京段近岸沉积物和土壤中重金属的空间分布特征,结果表明,几种重金属在沉积物中的富集次序为:Cd〉Pb〉Cr〉1〉Ni〉Cu〉Zn,在土壤中为:Cd〉Zn〉Cu〉1〉Cr〉Pb〉Ni,除zn和cu外,其他几种金属在沉积物中的富集程度高于土壤,同时cd的含量超过土壤环境质量三级标准。以cd和Pb为例分析了重金属含量与沉积物粒级之间的关系,回归分析显示,cd、Pb的含量与颗粒物的粒级呈显著的相关性,与细颗粒物的含量有密切关系,细颗粒携带的重金属,在长江水力分选作用下到达下游,成为沉积物中重金属的主要来源。  相似文献
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