全文获取类型
收费全文 | 539篇 |
免费 | 44篇 |
国内免费 | 127篇 |
专业分类
安全科学 | 73篇 |
废物处理 | 6篇 |
环保管理 | 91篇 |
综合类 | 318篇 |
基础理论 | 81篇 |
环境理论 | 4篇 |
污染及防治 | 26篇 |
评价与监测 | 16篇 |
社会与环境 | 67篇 |
灾害及防治 | 28篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 16篇 |
2021年 | 14篇 |
2020年 | 23篇 |
2019年 | 24篇 |
2018年 | 30篇 |
2017年 | 29篇 |
2016年 | 28篇 |
2015年 | 23篇 |
2014年 | 26篇 |
2013年 | 42篇 |
2012年 | 50篇 |
2011年 | 49篇 |
2010年 | 45篇 |
2009年 | 21篇 |
2008年 | 25篇 |
2007年 | 43篇 |
2006年 | 41篇 |
2005年 | 31篇 |
2004年 | 31篇 |
2003年 | 20篇 |
2002年 | 20篇 |
2001年 | 9篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1972年 | 1篇 |
排序方式: 共有710条查询结果,搜索用时 171 毫秒
171.
超滤与三维荧光光谱的结合可以表征不同类型荧光物质相对分子量的分布规律,揭示它们的来源以及组分差异.本项研究用截留相对分子量为1 000和10 000的再生纤维素超滤膜,对乌江水库不同深度水体中的溶解有机质进行了分离,利用三维荧光光谱表征了3种不同相对分子量组分中发荧光有机质的光谱特征.结果表明:荧光物质主要存在于真溶液(<1 000)中.水体在丰水期和枯水期的荧光峰存在差异.丰水期主要存在4种类型的荧光峰:类富里酸荧光A峰和C峰,类蛋白荧光峰B峰和D峰.枯水期则只表现出3种类型的荧光峰,类富里酸荧光峰C不明显,原因可能是此时水库处于蓄水状态,内部生物活动作用显著,产生的类蛋白荧光物质强度较大从而掩盖峰C的强度.然而72 m以下由于厌氧还原条件的出现,沉积物向水体释放了溶解有机质组分,原本强度被掩盖的荧光峰C明显出现在1 000~10 000组分中. 相似文献
172.
针对在推进城市化中发挥生态环境优势的探讨,文中介绍了中国固体废物的现状,包括固体废弃物的定义及分类和固体废弃物的危害特性,探讨了新型城市废弃物的产生和发展趋势,探讨了在中国城市废弃物对大气和水体的污染,最后提出了中国新型城市化建设与保护生态环境的建议,要积极加快固体废弃物资源化处理、要积极加快气体、液体有害物收集及回用、要积极重视建筑节能与新能源开发利用和要积极利用城市废弃物,使城市生活废弃物得到有效利用。 相似文献
173.
174.
以前三批29个国家"城市矿产"示范基地为研究对象,对示范基地的回收利用规模、重点项目覆盖范围、示范基地类型做了概括性梳理,总结了示范基地建设的成功经验,分析了妨碍示范基地健康发展的问题,并提出一些预测性意见,供行业同仁参考。 相似文献
175.
不同规模民用机场项目主要环境影响对比分析 总被引:1,自引:0,他引:1
刘海东 《中国ISO14000认证》2014,(6):31-35
按照在民航运输系统中所起的作用划分,我国民用机场可分为枢纽机场、干线机场和支线机场。由于建设规模、航空业务量不同,各类机场环境影响的范围、程度和特点也不尽相同。通过对国内机场建设项目环境影响的案例和相关研究成果进行总结,从声环境、环境空气、生态、水环境、固体废物等方面对比分析了不同规模机场的环境影响的特点,为机场选址、设计、规划等提供参考。 相似文献
176.
177.
Guangyu Qiao 《中国人口.资源与环境(英文版)》2013,11(4):324-329
In global climate change politics, China and India have worked closely with each other, representing two big emitters from the developing world. This article reviews Sino-Indian cooperation during four UN climate change negotiations from 2009 to 2012. Their collaboration echoed the perception of neorealism in international relations (IR) studies that states will seek “external balancing” for maximizing national “relative gains”. China and India are expected to continue their cooperation on climate change issues when sharing the same structural position as big economies and big emitters, the same pressure in carbon emission reductions, and the same goal of improving living standards for their citizens. Encountering the devastating impacts of climate change and the deadlock in responsibility division in current global climate change governance, this work seeks to shed light on the evolving multilateral governance environment and its complex implications for Sino-Indian relations from an IR perspective. 相似文献
178.
Abstract: Open access (OA) publishing, whereby authors, their institutions, or their granting bodies pay or provide a repository through which peer‐reviewed work is available online for free, is championed as a model to increase the number of citations per paper and disseminate results widely, especially to researchers in developing countries. We compared the number of citations of OA and non‐OA papers in six journals and four books published since 2000 to test whether OA increases number of citations overall and increases citations made by authors in developing countries. After controlling for type of paper (e.g., review or research paper), length of paper, authors’ citation profiles, number of authors per paper, and whether the author or the publisher released the paper in OA, OA had no statistically significant influence on the overall number of citations per journal paper. Journal papers were cited more frequently if the authors had published highly cited papers previously, were members of large teams of authors, or published relatively long papers, but papers were not cited more frequently if they were published in an OA source. Nevertheless, author‐archived OA book chapters accrued up to eight times more citations than chapters in the same book that were not available through OA, perhaps because there is no online abstracting service for book chapters. There was also little evidence that journal papers or book chapters published in OA received more citations from authors in developing countries relative to those journal papers or book chapters not published in OA. For scholarly publications in conservation biology, only book chapters had an OA citation advantage, and OA did not increase the number of citations papers or chapters received from authors in developing countries. 相似文献
179.
ABSTRACTSiting controversies have become familiar in windpower development. Process and outcome fairness in the form of economic benefits to local communities and inclusion in decision-making processes are recognised as important elements in local acceptance of windpower installations. To these, we add the concept of “relative fairness” influencing perceptions of overall fairness. In this article, we examine why Norwegian municipalities agree to host windpower, and the role of process, outcome and relative fairness in this decision. Municipalities are central in providing welfare services, and in ensuring a viable local economy and local workplaces. Process fairness is important, as is evident when municipalities have little influence in the detailed planning of the plants. Also, outcome fairness, in the form of economic compensation – particularly through property tax – is decisive for positive attitudes towards windfarms, as municipalities can strengthen their role as welfare providers and boost local economic activities. Less emphasised are the effects on global climate and national climate goals. However, effects on local landscape and nature are also important for municipalities, as became clear when the national government proposed withdrawing the municipalities’ possibilities of levying property taxes. The municipalities argue that it is only fair to receive something in return for hosting windmills, and relative fairness is important to their argument for equal treatment regarding hydro- and wind-power electricity production in the form of a natural resource tax. 相似文献
180.
Kai-Lai G. Ho Anthony L. Pometto III Paul N. Hinz 《Journal of Polymers and the Environment》1999,7(2):83-92
Three high molecular weight (120,000 to 200,000 g mol–1) polylactic acid (PLA) plastic films from Chronopol (Ch-I) and Cargill Dow Polymers (GII and Ca-I) were analyzed for their degradation under various temperature and relative humidity (RH) conditions. Two sets of plastic films, each containing 11 samples, were randomly hung in a temperature/humidity-controlled chamber by means of plastic-coated paper clips. The tested conditions were 28, 40, and 55°C at 50 and 100% RH, respectively, and 55°C at 10% RH. The three tested PLA films started to lose their tensile properties when their weight-average molecular weight (M
w) was in the range of 50,000 to 75,000 g mol–1. The average degradation rate of Ch-I, GII, and Ca-I was 28,931, 27,361, and 63,025 M
w/week, respectively. Hence, GII had a faster degradation rate than Ch-I and Ca-I under all tested conditions. The degradation rate of PLA plastics was enhanced by the increase in temperature and relative humidity. This trend was observed in all three PLA plastics (Ca-I, GII, and Ch-I). Of the three tested films, Ch-I was the first to lose its mechanical properties, whereas Ca-I demonstrated the slowest loss, with mechanical properties under all tested conditions. 相似文献