全文获取类型
收费全文 | 333篇 |
免费 | 44篇 |
国内免费 | 208篇 |
专业分类
安全科学 | 29篇 |
废物处理 | 26篇 |
环保管理 | 19篇 |
综合类 | 247篇 |
基础理论 | 94篇 |
污染及防治 | 128篇 |
评价与监测 | 21篇 |
社会与环境 | 13篇 |
灾害及防治 | 8篇 |
出版年
2024年 | 3篇 |
2023年 | 11篇 |
2022年 | 45篇 |
2021年 | 38篇 |
2020年 | 41篇 |
2019年 | 27篇 |
2018年 | 32篇 |
2017年 | 30篇 |
2016年 | 31篇 |
2015年 | 48篇 |
2014年 | 33篇 |
2013年 | 46篇 |
2012年 | 35篇 |
2011年 | 31篇 |
2010年 | 26篇 |
2009年 | 19篇 |
2008年 | 18篇 |
2007年 | 17篇 |
2006年 | 7篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 11篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 9篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
排序方式: 共有585条查询结果,搜索用时 15 毫秒
2.
Boundaries between different forest types in Changbai Mountain Eatern China are results from complex interactions between forest ecosystems,topogrphy,and geomorphology.Detecting and quantifying the transitional zones are highly important since high environmental beterogeneity and biodiversity are ofter found within these zpmes.In this study,we used GIS and multivariate statistics techniques(PCA and MSWA) to analyze data from Landsat TM satellite imageries and quantitatively determined the positions and widths of the landscape boundary betweeen mountain birch and evergreen coniferous forests in the northern slope of Changbai Mountain.The results showed that the widths of the landscape boundary ranges from 30-50 m while using the MWW A or/and PC method.Such detected widths are consistent with field transect data that suggest a 50m tranistional zone width.The results further suggest that TM data can be used in combination with GIS and statistical techniques in determining forest landscape boundaries.MSWA is more reliable than PCA,while PCA can also be used to determine the landscape boundary when transects are properly located. 相似文献
3.
针对我国煤中硫分赋存状况,抓源头治理,分别对高硫煤,中硫煤和低硫煤采取不同对策,切实有效地实现“两控区”2000年的初期目标。 相似文献
4.
农用土地价格评估——以新疆库尔勒市为例 总被引:13,自引:0,他引:13
根据农用土地的具体特征选择适当的方法和评估中具体的操作是本文探讨的重点。解决不同利用方式下农用土地收益差异的综合平衡计算是关键。结合库尔勒市农用土地分等定级的具体实践,建立一套较为完整的农用土地价格评估体系,为今后开展的工作提供范例。 相似文献
5.
Cheng Zhu Aganovic Amar Cao Guangyu Bu Zhongming 《Environmental science and pollution research international》2021,28(24):30642-30663
Environmental Science and Pollution Research - The traditional mixing ventilation is not an energy effective approach to remove indoor air pollutants, maintain breath zone air quality, and control... 相似文献
6.
Zihong Xia Jian Li Tingting Wu Caixia Chen Xiaoke Zhang 《Waste management (New York, N.Y.)》2014,34(9):1609-1618
A CFD scheme was presented for modeling municipal solid waste (MSW) combustion in a moving-grate incinerator, including the in-bed burning of solid wastes, the out-of-bed burnout of gaseous volatiles, and the selective non-catalytic reduction (SNCR) process between urea (CO(NH2)2) and NOx. The in-bed calculations provided 2-D profiles of the gas–solid temperatures and the gas species concentrations along the bed length, which were then used as inlet conditions for the out-of-bed computations. The over-bed simulations provided the profiles of incident radiation heat flux on the top of bed. A 3-dimensional benchmark simulation was conducted with a 750 t/day commercial incinerator using the present coupling scheme incorporating with a reduced SNCR reduction mechanism. Numerical tests were performed to investigate the effects of operating parameters such as injection position, injection speed and the normalized stoichiometric ratio (NSR) on the SNCR performance. The simulation results showed that the distributions of gas velocity, temperature and NOx concentration were highly non-uniform, which made the injection position one of the most sensitive operating parameters influencing the SNCR performance of moving grate incinerators. The simulation results also showed that multi-layer injections were needed to meet the EU2000 standard, and a NSR 1.5 was suggested as a compromise of a satisfactory NOx reduction and reasonable NH3 slip rates. This work provided useful guides to the design and operation of SNCR process in moving-grate incinerators. 相似文献
7.
Zhou Daqing Zhang Haonan Zhang Xingshuo Zhang Wenwen Zhang Tingting Lu Changhu 《Environmental science and pollution research international》2021,28(39):54719-54727
Environmental Science and Pollution Research - The red-crowned crane (Grus japonensis) is an endangered bird species that has been listed as one of the Class I National Key Protected Wild Animals... 相似文献
8.
9.
10.
生态环境保护目标指标是环境保护和生态建设规划中的核心内容,制定科学合理的规划指标体系,能够确保规划各项重点任务顺利实施.通过回顾分析"十一五"、"十二五"环境保护和生态建设规划指标体系,结合广西环境现状和发展趋势,在与国家和广西同期规划、计划、方案等衔接基础上,研究提出广西"十三五"环境保护和生态建设规划指标体系,设置了环境质量改善、总量控制、污染治理、风险防范、生态保护和生态公共服务等6个方面共29个指标,以期更好地指导"十三五"环境保护和生态建设工作. 相似文献