全文获取类型
收费全文 | 3096篇 |
免费 | 357篇 |
国内免费 | 1027篇 |
专业分类
安全科学 | 404篇 |
废物处理 | 111篇 |
环保管理 | 253篇 |
综合类 | 2226篇 |
基础理论 | 486篇 |
污染及防治 | 470篇 |
评价与监测 | 211篇 |
社会与环境 | 200篇 |
灾害及防治 | 119篇 |
出版年
2024年 | 19篇 |
2023年 | 73篇 |
2022年 | 183篇 |
2021年 | 188篇 |
2020年 | 232篇 |
2019年 | 166篇 |
2018年 | 179篇 |
2017年 | 188篇 |
2016年 | 149篇 |
2015年 | 203篇 |
2014年 | 196篇 |
2013年 | 296篇 |
2012年 | 325篇 |
2011年 | 298篇 |
2010年 | 253篇 |
2009年 | 232篇 |
2008年 | 208篇 |
2007年 | 213篇 |
2006年 | 199篇 |
2005年 | 139篇 |
2004年 | 90篇 |
2003年 | 87篇 |
2002年 | 98篇 |
2001年 | 69篇 |
2000年 | 54篇 |
1999年 | 44篇 |
1998年 | 25篇 |
1997年 | 20篇 |
1996年 | 18篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有4480条查询结果,搜索用时 31 毫秒
991.
火电厂较一般的工业项目源强较多,以某35万千瓦超临界间接空冷火电厂为例,采用Cadna/A噪声预测软件预测了投产后产生的噪声影响,预测结果表明火电厂企业采取相应的降噪措施后,厂界噪声能够满足《工业企业厂界环境噪声排放标准》(GB12348-2008)中的3类标准要求,对环境敏感点昼夜噪声预测值能满足《声环境质量标准》(GB3096-2008)的2类标准要求,说明该项目的降噪设计可行。 相似文献
992.
Jinheng Zhang Lusheng Zeng Yonghong Sun Chaoyu Song Hui Wang Jianmei Chen 《毒物与环境化学》2015,97(3-4):454-463
The aim of this study was to investigate canopy spectral reflectance responses to different levels of heavy metals copper (Cu), zinc (Zn), and cadmium (Cd) induced stress. Random blocks design experiment was conducted to simulate Cu, Zn, and Cd at five concentration levels. Chlorophyll and visible and near infrared canopy reflectance were measured for each treatment 56 days after seeding using chlorophyll meter SPAD-502 and spectroradiometer, respectively. New vegetative indices termed ratio of inclination angles (RIA), MERIS (the medium resolution imaging spectrometer) terrestrial chlorophyll index (MTCI), and normalized difference vegetation index (NDVI) were used to assess the response of canopy spectral reflectance to different heavy metal levels. Significant spectral variability especially in blue, red, and near infrared reflectance was observed for different heavy metal treatments. One-sample test showed significant difference for NDVI, MTCI, and RIA among five-level treatments at the 0.01 level. Correlation analysis demonstrated that the two vegetative indices (RIA and MTCI) were significantly correlated with chlorophyll meter values for Cd, Cu, and Zn treatments. However, NDVI was only significantly correlated with chlorophyll meter values for Cu and Zn treatments. Linear regression analysis also illustrated that RIA and MTCI were potential indices for predicting chlorophyll concentration with significant F test under Cu-, Zn-, and Cd-mediated stress. 相似文献
993.
浅析辽河流域水环境管理现状及改善措施 总被引:1,自引:0,他引:1
辽河流域是我国北方重要的河流型流域,水环境污染问题突出。文章从水环境管理体制、水污染控制方式、水生态安全管理、预警监控4个方面剖析了辽河流域水环境管理现状,并提出针对性的改善措施,对促进辽河流域水环境管理能力提高具有积极的实际意义。 相似文献
994.
995.
996.
Human settlement and regional development in the context of climate change: a spatial analysis of low elevation coastal zones in China 总被引:1,自引:0,他引:1
997.
998.
Development of EMC-based empirical model for estimating spatial distribution of pollutant loads and its application in rural areas of Korea 总被引:1,自引:0,他引:1
An integrated approach to easily calculate pollutant loads from agricultural watersheds is suggested and verified in this research. The basic concepts of this empirical tool were based on the assumption that variations in event mean concentrations (EMCs) of pollutants from a given agricultural watershed during rainstorms were only attributable to the rainfall pattern. Fifty one sets of EMC values were obtained from nine different watersheds located in the rural areas of Korea, and these data were used to develop predictive tools for the EMCs in rainfall runoff. The results of statistical tests of these formulas show that they are fairly good in predicting actual EMC values of some parameters, and useful in terms of calculating pollutant loads for any rainfall event time span such as daily, weekly, monthly, and yearly. This model was further checked in for its field applicability in a reservoir receiving stormwater after a cleanup of the sediments, covering 17 consecutive rainfall events from 1 July to 15 August in 2007. Overall the predicted values matched the observed values, indicating the feasibility of this empirical tool as a simple and useful solution in evaluating timely distribution of nonpoint source pollution loads from small rural watersheds of Korea. 相似文献
999.
Perfluorononanoic acid (PFNA) is a nine-carbon perfluoroalkyl acid widely used in industrial and domestic products. It is a persistent organic pollutant found in the environment as well as in the tissues of humans and wildlife. There is a concern that this chemical might be a developmental toxicant and teratogen in various ecosystems. In the present study, the toxic effects of PFNA were evaluated in zebrafish (Danio rerio) embryos. One hour post-fertilization embryos were treated with 0, 25, 50, 100, 200, 300, 350, and 400 μmol/L PFNA for 96 hr in 6-well plates. Developmental phenotypes and hatching rates were observed and recorded. Nineteen genes related to oxidative stress and lipid metabolism were examined using Quantitative RT-PCR and confirmed by whole mount in situ hybridization (WISH). Results showed that PFNA delayed the development of zebrafish embryos, reduced the hatching rate, and caused ventricular edema and malformation of the spine. In addition, the amount of reactive oxygen species in the embryo bodies increased significantly after exposure to PFNA compared with that of the control group. The Quantitative RT-PCR and WISH experiments demonstrated that mRNA expression of the lfabp and ucp2 genes increased significantly while that of sod1 and mt-nd1 decreased significantly after PFNA exposure. The mRNA expression levels of gpx1 and mt-atp6 decreased significantly in the high concentration group. However, the mRNA expression levels of both ppara and pparg did not show any significant variation after exposure. These findings suggest that PFNA affected the development of zebrafish embryos at relatively low concentrations. 相似文献
1000.