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531.
Klöpffer W 《Environmental science and pollution research international》2005,12(3):173-177
Background LCA is the only internationally standardized environmental assessment tool (ISO 14040-43) for product systems, including services and processes. The analysis is done from cradle-to-grave, i.e. over the whole life cycle. LCA is essentially a comparative method: different systems fulfilling the same function (serving the same purpose) are compared on the basis of a functional unit - a quantitative measure of this function or purpose. It is often believed that LCA can be used for judging the (relative) sustainability of product systems. This is only partly true, however, since LCA is restricted to the environmental part of the triad environment/ecology - economy - social aspects (including intergenerational fairness) which constitutes sustainability. Standardized assessment tools for the second and the third part are still lacking, but Life Cycle Costing (LCC) seems to be a promising candidate for the economic part. Social Life Cycle Assessment still has to be developed on the basis of known social indicators.Method and Limitations LCA is most frequently used for the comparative assessment or optimization analysis of final products. Materials and chemicals are difficult to analyse from cradle-to-grave, since they are used in many, often innumerable product systems, which all would have to be studied in detail to give a complete LCA of a particular material or substance! This complete analysis of a material or chemical is evidently only possible in such cases where one main application exists. But even if one main application does exist, e.g. in the case of surfactants (chemicals) and detergents (final products), the latter may exist in a great abundance of compositions. Therefore, chemicals and materials are better analysed from cradle-to-factory gate, leaving the analysis of the final product(s), the use phase and the end-of-life phases to specific, full LCAs.Conclusion A comparative assessment of production processes is possible, if the chemicals (the same is true for materials) produced by different methods have exactly the same properties. In this case, the downstream phases may be considered as a black box and left out of the assessment. Such truncated LCAs can be used for environmental comparisons, but less so for the (environmental) optimization analysis of a specific chemical: the phases considered as black box and left out may actually be the dominant ones. A sustainability assessment should be performed at the product level and contain the results of LCC and social assessments. Equal and consistent system boundaries will have to be used for these life cycle tools which only together can fulfil the aim of assessing the sustainability of product systems. 相似文献
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不同原料和炭化温度下制备的生物炭结构及性质 总被引:6,自引:0,他引:6
以麦秆、稻杆和松木屑3种生物质为原料,在控制热分解条件下制备生物炭利用TG/DTG、Boehm滴定、FT-IR、XRD、TEM和吸附实验等方法对不同原料在350、550和750℃ 3个炭化温度下制备的生物炭形貌及其表面化学性质进行了表征。结果表明:最大热解速率所对应温度以松木屑为最高,表示热稳定性最好;不同原料在相同炭化温度下所制得的生物炭所含表面含氧官能团种类和总量相近,但pH值和吸附能力差别较大,其中麦秆制得的生物炭pH值最大,松木屑制得的生物炭吸附能力最强;随着炭化温度升高,相同原料制得生物炭表面含氧官能团总量减少,pH值升高,纤维素和半纤维素特征峰消失,芳构化程度增加,吸附性能总体呈先上升后下降的趋势。 相似文献
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Reactions between the SO4·- radical and some common anions in atmospheric aqueous droplets 总被引:2,自引:0,他引:2
IntroductionThe conversion processes of some atmospheric pollutantsinside the aqueous droplets e .g. clouds , rains and fogspresent interesting topics to discuss . One typical example ofthis kind of pollutants was SO2. It can dissolve into thedroplets rea… 相似文献
536.
Tickner JA Geiser K Coffin M 《Environmental science and pollution research international》2005,12(2):115-123
- Sustainable chemistry - Section editors:
Klaus Günter Steinhäuser, Steffi Richter, Petra Greiner, Jutta Penning, Michael AngrickBackground, Aim and Scope Recent developments in European chemicals policy, including the Registration, Evaluation and Authorization of Chemicals (REACH) proposal, provide a unique opportunity to examine the U.S. experience in promoting sustainable chemistry as well as the strengths and weaknesses of existing policies. Indeed, the problems of industrial chemicals and limitations in current regulatory approaches to address chemical risks are strikingly similar on both sides of the Atlantic. We provide an overview of the U.S. regulatory system for chemicals management and its relationship to efforts promoting sustainable chemistry. We examine federal and state and examine lessons learned from this system that can be applied to developing more integrated, sustainable approaches to chemicals management.Main Features There is truly no one U.S. chemicals policy, but rather a series of different un-integrated policies at the federal, regional, state and local levels. While centerpiece U.S. Chemicals Policy, the Toxic Substances Control Act of 1976, has resulted in the development of a comprehensive, efficient rapid screening process for new chemicals, agency action to manage existing chemicals has been very limited. The agency, however, has engaged in a number of successful, though highly underfunded, voluntary data collection, pollution prevention, and sustainable design programs that have been important motivators for sustainable chemistry. Policy innovation in the establishment of numerous state level initiatives on persistent and bioaccumulative toxics, chemical restrictions and toxics use reduction have resulted in pressure on the federal government to augment its efforts.Results and Conclusions It is clear that data collection on chemical risks and phase-outs of the most egregious chemicals alone will not achieve the goals of sustainable chemistry. These alone will also not internalize the cultural and institutional changes needed to ensure that design and implementation of safer chemicals, processes, and products are the focus of the future. Thus, a more holistic approach of ‘carrots and sticks’ that involves not just chemical producers but those who use and purchase chemicals is necessary. Some important lessons of the US experience in chemicals management include: (1) the need for good information on chemicals flows, toxic risks, and safer substances.; (2) the need for comprehensive planning processes for chemical substitution and reduction to avoid risk trade-offs and ensure product quality; (3) the need for technical and research support to firms for innovation in safer chemistry; and (4) the need for rapid screening processes and tools for comparison of alternative chemicals, materials, and products. 相似文献
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侯马市酸雨长期变化趋势分析 总被引:6,自引:2,他引:4
根据1992年至2008年的酸雨观测记录,对侯马市的酸雨变化特征及其长期趋势进行了统计分析.结果表明,17年间,除个别年份外,侯马地区的降水pH值长期低于5.6,2006年以来甚至低于4.5,多年平均pH值为4.88,是我国长江以北地区酸雨污染最严重的地区.降水pH值的平均月际变化幅度为0.8pH单位,呈不规则起伏变化.在降水集中的7、8、9月间,酸沉降量约占全年的60%.作为出现在我国北方的区域性酸雨地区,侯马地区降水酸度2002年前后呈现不同的变化趋势,2002年前,降水pH值平均年变率约为0.10a-1,酸雨污染呈现减弱趋势,而之后的pH值平均年变率约为-0.28a-1,呈现酸雨污染快速加重的变化趋势.该地区降水量的变化不仅对单次降水的酸性有较明显的影响,而且对降水酸度的季节变化和年际变化也有明显影响,显示当地的大气颗粒物具有显著的碱性中和能力.2007年对降水离子成分的加强观测分析结果显示,SO42-、NO3-、Ca2+、NH4+是降水中最主要的离子;[1/2]SO42-与NO3-的比值约为6.9,说明当地的酸雨为较明显的硫酸型污染;降水中NH4+含量较高,大约与[1/2]Ca2+的离子含量相当;主成分因子分析显示,[1/2]SO42-、NO3-、[1/2]Ca2+、NH4+4种离子含量的变化存在显著相关,当地的焦煤、煤化工等高污染排放可能是其重要的共同来源. 相似文献