全文获取类型
收费全文 | 23752篇 |
免费 | 4113篇 |
国内免费 | 8467篇 |
专业分类
安全科学 | 4295篇 |
废物处理 | 439篇 |
环保管理 | 2150篇 |
综合类 | 19723篇 |
基础理论 | 3424篇 |
污染及防治 | 1897篇 |
评价与监测 | 1654篇 |
社会与环境 | 1748篇 |
灾害及防治 | 1002篇 |
出版年
2024年 | 312篇 |
2023年 | 860篇 |
2022年 | 1856篇 |
2021年 | 1905篇 |
2020年 | 2229篇 |
2019年 | 1519篇 |
2018年 | 1413篇 |
2017年 | 1754篇 |
2016年 | 1432篇 |
2015年 | 1604篇 |
2014年 | 1408篇 |
2013年 | 1830篇 |
2012年 | 2317篇 |
2011年 | 2211篇 |
2010年 | 2086篇 |
2009年 | 1909篇 |
2008年 | 1745篇 |
2007年 | 1745篇 |
2006年 | 1721篇 |
2005年 | 1266篇 |
2004年 | 884篇 |
2003年 | 590篇 |
2002年 | 545篇 |
2001年 | 443篇 |
2000年 | 377篇 |
1999年 | 198篇 |
1998年 | 49篇 |
1997年 | 27篇 |
1996年 | 26篇 |
1995年 | 24篇 |
1994年 | 19篇 |
1993年 | 9篇 |
1992年 | 16篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 159 毫秒
151.
152.
通过对2014—2016年湖体水质中氮素质量浓度分析,结合出入湖总氮浓度、水量、湖体水生生态等影响因素,发现太湖水体中总氮浓度呈现逐年下降的趋势,各监测点位总氮为0.530 mg/L~5.51 mg/L,时空分布不均,差异明显。时间上,总氮浓度表现为春季最高,夏季和秋季最低,且月均值变化曲线呈现出规律的正弦函数波形。空间上,总氮浓度大致表现出由西部湖区向东部湖区递减的趋势,呈现西部湖区﹥北部湖区﹥南部湖区﹥湖心区﹥东部湖区。要改善湖体水质,不仅要切断污染源,而且要加强水生生态功能修复。 相似文献
153.
16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in water samples from the Jinsha River (Panzhihua part), Southwest China. Total dissolved PAH concentrations varied from 21.89 microg l(-1) to 382.8 microg l(-1). It was found that the concentration of PAHs decreased along the flow direction due to the higher density distribution of coal chemical industry in the upstream of our study rivers. The pollution levels in our study area are significantly higher than previously reported values in other waters both in China and other countries. The predominance of benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene was clearly observed in all water samples. On average these two compounds accounted for 98.3% of the total dissolved PAH concentration in water. The results showed the positive correlations among total dissolved PAHs, benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene, which suggested that these two predominant PAHs have similar source and environmental behaviors in our study area. When compared with the survey results of organic micropollutants two decades ago, it was found that hydrocarbon pollution both predominated and even increased with the development of coal chemical industry in this area during the past 20 years. The results therefore provide important information on the current contamination status of a key industrial city in China, and points to the need for urgent action to investigate the relationship between the PAH composition and concentration in water from the Jinsha River and the wastewater discharge from coal chemical industry, and to identify the source, transport pathway and fate of PAHs in the area. It should then be necessary to adopt appropriate and instant measures to control the pollution around this area. 相似文献
154.
通过对新疆著名旅游城市吐鲁番的空气环境、水环境、声环境、景观生态环境等环境质量存在的问题进行分析,针对性地提出了相应的环保对策及建议,为吐鲁番市的环境保护工作提供参考。 相似文献
155.
介绍了南京市环境监测中心站近年来在拓展监测能力,提升监测现代化水平,优化资源配置,加强队伍建设,强化制度建设,实施目标管理等方面采取的举措,指出在我国环境保护发生历史性转变的关键时期,环境监测站应在社会、经济、环境的协调发展中,充分发挥为管理服务的前瞻性、监测信息上报的及时性及实施环境决策的支持性作用,积极推进环境监测事业持续发展. 相似文献
156.
157.
158.
探讨装修污染室内环境的机制及治理 总被引:2,自引:1,他引:2
装修污染室内环境是不能避免的,掌握必要的环保知识,对于预防和治理室内环境的污染、减小因室内环境污染对人体的危害,就显得尤为重要和迫切。有效的预防和治理室内环境的污染,则减少对室外环境的污染,从而保护了生态环境。 相似文献
159.
Adsorption of zinc on manganite(γ-MnOOH): particle concentration effect and adsorption reversibility
The adsorption and desorption processes of Zn(Ⅱ) on τ-MnOOH as a function of particle concentrations (Cp) were studied. An obvious Cp effect was observed in this adsorption system. The degree of adsorption hysteresis increased greatly with the increasing of Cp, indicating that the extent of the real metastable-equilibrium states deviating from the ideal equilibrium state was enhanced with the increasing of Cp. The Cp-reversibility relationship confirmed the metastable-equilibrium adsorption (MEA) inequality (Pan, 1998a), which was the core formulation of the MEA theory. Because the MEA inequality was based on the basic hypothesis of MEA theory that adsorption densitιy ι is not a state variable, the Cp-reversibility relationship gave indirect evidence to the basic hypothesis of MEA theory. 相似文献
160.