全文获取类型
收费全文 | 1253篇 |
免费 | 167篇 |
国内免费 | 238篇 |
专业分类
安全科学 | 254篇 |
废物处理 | 23篇 |
环保管理 | 150篇 |
综合类 | 741篇 |
基础理论 | 146篇 |
污染及防治 | 71篇 |
评价与监测 | 102篇 |
社会与环境 | 96篇 |
灾害及防治 | 75篇 |
出版年
2024年 | 2篇 |
2023年 | 23篇 |
2022年 | 43篇 |
2021年 | 67篇 |
2020年 | 59篇 |
2019年 | 68篇 |
2018年 | 50篇 |
2017年 | 62篇 |
2016年 | 81篇 |
2015年 | 65篇 |
2014年 | 74篇 |
2013年 | 92篇 |
2012年 | 125篇 |
2011年 | 91篇 |
2010年 | 72篇 |
2009年 | 72篇 |
2008年 | 42篇 |
2007年 | 80篇 |
2006年 | 79篇 |
2005年 | 58篇 |
2004年 | 46篇 |
2003年 | 41篇 |
2002年 | 24篇 |
2001年 | 25篇 |
2000年 | 20篇 |
1999年 | 35篇 |
1998年 | 26篇 |
1997年 | 14篇 |
1996年 | 17篇 |
1995年 | 21篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1992年 | 14篇 |
1991年 | 16篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1980年 | 3篇 |
1977年 | 1篇 |
1973年 | 3篇 |
排序方式: 共有1658条查询结果,搜索用时 31 毫秒
941.
Johannes Klein 《Local Environment》2016,21(2):254-271
Calls for more stakeholder participation and cooperation, the acknowledgement of uncertainties as well as for flexible and robust solutions have become frequent in the literature on climate change adaptation. Recent studies show that these calls are taken up only reluctantly in local adaptation compared to sectoral and technical solutions. The aim of this study is to examine to which extent adaptation as an embedded process within the local context allows for stakeholder participation, cooperation and the robustness and flexibility of adaptation measures. It applies an analytical approach, combining an action framework of adaptation and document-based discourse analysis, to assess both the procedural and the substantive viewpoint of an adaptation case in Finland. This twofold approach provides insight into how the adaptation process and content influence and condition each other. The analysis highlights how new approaches to adaptation have to compete with prevailing discourses and institutionalised practices, as public authorities take the dominant role in adaptation, striving for certain and safe solutions. This process has few participatory elements and leaves little leeway to address uncertainty. 相似文献
942.
943.
鄱阳湖表层水中全氟辛酸和全氟辛烷磺酸污染现状调查 总被引:1,自引:0,他引:1
为阐明鄱阳湖表层水中全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)的污染现状,于2011年4月7~9日采集鄱阳湖的表层水样30份和长江水样2份,采用超高效液相色谱-三重四极杆串联质谱/质谱法检测样品中PFOS和PFOA含量,探索鄱阳湖表层水中PFOS和PFOA的污染水平及空间分布特征。结果表明: PFOS和PFOA的浓度范围分别为未检出~071 ng/L和030 ~189 ng/L,均值分别为035 ng/L和110 ng/L。而位于长江的0号点水中PFOA和PFOS含量分别为1511 ng/L和081 ng/L。鄱阳湖表层水中的PFOS和PFOA在整体上都呈现南部高于北部的趋势,这可能是由鄱阳湖的水动力条件和其周边PFCs污染源分布不同所致。以上研究结果显示,鄱阳湖表层水中PFOS和PFOA处于较低的污染水平 相似文献
944.
采用《省级主体功能区划分技术规程》中经济发展水平指标的计算方法,以内蒙古101个旗、县、区为研究对象,选取各地GDP产值和人均GDP数值,探讨2000-2004年和2005-2009年两个时段内蒙古县域经济发展变化状况.结果表明,内蒙古县域经济发展水平的时空差异十分显著,县域经济发展水平差距在逐渐扩大,各地区经济发展极不均衡,这种时空差异与内蒙古各县区的地理位置、经济基础、资源禀赋、发展策略、人力资源等紧密相关. 相似文献
945.
Species- and tissue-specific accumulation of Dechlorane Plus in three terrestrial passerine bird species from the Pearl River Delta, South China 总被引:1,自引:0,他引:1
Little data is available on the bioaccumulation of Dechlorane Plus (DP) in terrestrial organisms. Three terrestrial passerine bird species, light-vented bulbul, long-tailed shrike, and oriental magpie-robin, were collected from rural and urban sites in the Pearl River Delta to analyze for the presence of DP and its dechlorinated products in muscle and liver tissues. The relationships between trophic level and concentration and isomeric composition of DP in birds were also investigated based on stable nitrogen isotope analysis. DP levels had a wide range from 3.9 to 930 ng g−1 lipid weight (lw) in muscle and from 7.0 to 1300 ng g−1 lw in liver. Anti-Cl11-DP and syn-Cl11-DP, two dechlorinated products of DP, were also detected in bird samples with concentrations ranged between not detected (nd)-41 and nd-7.6 ng g−1 lw, respectively. DP preferentially accumulated in liver rather than in muscle for all three bird species. Birds had significantly higher concentrations of DP in urban sites than in rural sites (mean, 300 vs 73 ng g−1 lw). The fractions of anti-DP (fanti) were higher in birds collected in rural sites than in urban sites. Significant positive correlation between DP levels and δ15N values but significant negative correlation between fanti and δ15N values were found for birds in both urban and rural sites, indicating that trophic level of birds play an important role in determining DP level and isomeric profile. 相似文献
946.
为减轻水体污染,缓解环境压力,对典型城镇污染河水进行气动絮凝实验研究。在设定的实验条件下,以某大学中水站格栅后生活污水稀释配制的水样来模拟典型城镇污染河水并作为实验研究对象,以无机高分子聚合物聚合氯化铁铝(PFAC)为絮凝剂,有机高分子聚合物聚丙烯酰胺(PAM)为助凝剂。在此基础上,以浊度、COD、总磷和溶解氧为测定指标,采用连续流的方式进行一系列实验研究。实验结果显示:采用微孔曝气头进行曝气,当混合阶段充气量及絮凝池第一格、第二格充气量分别为1.778 m3空气/m3处理污水量、1.444 m3空气/m3处理污水量和0.622 m3空气/m3处理污水量时,城镇污染河水中污染物的去除效果最佳。其浊度、COD、TP的去除率可分别达93.6%、68.6%和73.5%。此外,在处理效果良好的前提下,沉淀池出水口出水溶解氧含量均能保持在2.29 mg/L左右。 相似文献
947.
Maddalena Cabizza Maurizio Satta Susanna Falconi Minica Onano Giovanni Uccheddu 《Journal of environmental science and health. Part. B》2013,48(7):761-766
Degradation of two fungicides (cyprodinil and fludioxonil) and two insecticides (cyfluthrin and pymetrozine) applied on iceberg and romaine lettuce under field conditions with different methods (portable mistblower and chemigation) was studied field data showed that both distribution methods and lettuce cultivar affect the degradation trends of examined pesticides. In these trials the residues of all active ingredients after pre-harvest time were less than fifty's maximum residue levels; the values in the romaine cultivar were generally higher than those in iceberg lettuce. After pre-harvest time residues of pesticides applied on romaine lettuce by portable motor sprayer were always higher than those obtained by the chemigation system. 相似文献
948.
对SCR脱硝催化剂积灰堵塞原因及对空预器的影响进行了简要分析。介绍了SCR催化剂使用可调频高声强声波吹灰器进行声疲劳和抗压强度试验,结果表明,该新型声波吹灰器不会对SCR催化剂造成损坏。 相似文献
949.
基于野外定点监测数据,运用统计学方法解析鄱阳湖区地下水位年内分布特征和动态变化,辨析湖水和典型区地下水之间的侧向水力联系与程度。统计结果表明,不同洲滩地下水埋深变化范围约–8.1~–0.1 m,洲滩地下水和湖水在6~9月份保持完全水力连通。湖水位和洲滩地下水位动态变化呈现高度一致性,表明了洲滩地下水和湖水具有密切的侧向水力联系。湖岸带不同典型区的地下水埋深变化范围介于–10~–2.2 m。湖岸带地下水位与湖水位并不具有日时间尺度变化上的高度一致性,但两者却很好呈现了月尺度上的较好一致性,表明了湖岸带地下水与湖水之间具有一定的相互关系和水力联系。小波分析得出,湖水位和洲滩、湖岸带不同典型区的地下水位均在60 d尺度的周期上存在着极大可能的显著相关,总体上两者呈正相关关系变化,表明湖水和洲滩地下水具有密切的水力联系,但与湖岸带地下水的侧向水力联系可能体现在个别典型时段。为今后鄱阳湖地下水方面的相关研究奠定基础,也为鄱阳湖湿地生态环境保护、水资源评价等方面提供科学依据和参考。 相似文献
950.
《Journal of environmental science and health. Part. B》2013,48(5):561-570
Data on the short‐term effects of fumigation with hydrogen fluoride (HF) on the response behavior of the Nicotiana tabacum L. cv. St. Karabalar 6265 are being presented. Growth rate, fluoride accumulation in leaves and soils, and degradation in chlorophyll and nicotine contents of the plant species against the variations in two experimental factors, namely the exposure concentration and exposure time parameters, were investigated. Resulting data reveals that the variety selected for this study is not so tolerant to fluoride as generally reported in the literature, if only the individual effects of the pollutant is considered. 相似文献