全文获取类型
| 收费全文 | 744篇 |
| 免费 | 205篇 |
| 国内免费 | 64篇 |
专业分类
| 安全科学 | 54篇 |
| 废物处理 | 55篇 |
| 环保管理 | 52篇 |
| 综合类 | 363篇 |
| 基础理论 | 156篇 |
| 污染及防治 | 249篇 |
| 评价与监测 | 29篇 |
| 社会与环境 | 26篇 |
| 灾害及防治 | 29篇 |
出版年
| 2024年 | 14篇 |
| 2023年 | 25篇 |
| 2022年 | 41篇 |
| 2021年 | 37篇 |
| 2020年 | 25篇 |
| 2019年 | 28篇 |
| 2018年 | 25篇 |
| 2017年 | 37篇 |
| 2016年 | 34篇 |
| 2015年 | 59篇 |
| 2014年 | 54篇 |
| 2013年 | 74篇 |
| 2012年 | 47篇 |
| 2011年 | 59篇 |
| 2010年 | 43篇 |
| 2009年 | 29篇 |
| 2008年 | 35篇 |
| 2007年 | 50篇 |
| 2006年 | 33篇 |
| 2005年 | 24篇 |
| 2004年 | 18篇 |
| 2003年 | 23篇 |
| 2002年 | 19篇 |
| 2001年 | 17篇 |
| 2000年 | 22篇 |
| 1999年 | 31篇 |
| 1998年 | 17篇 |
| 1997年 | 16篇 |
| 1996年 | 15篇 |
| 1995年 | 9篇 |
| 1994年 | 9篇 |
| 1993年 | 9篇 |
| 1992年 | 10篇 |
| 1991年 | 7篇 |
| 1990年 | 7篇 |
| 1989年 | 3篇 |
| 1988年 | 2篇 |
| 1987年 | 1篇 |
| 1986年 | 2篇 |
| 1982年 | 2篇 |
| 1981年 | 1篇 |
排序方式： 共有1013条查询结果，搜索用时 15 毫秒
601.
为了进一步提高电除尘器的收尘效率,满足国家新的烟尘排放标准,依据研究建立的非稳态静电收集理论,提出了电除尘器供电电压及振打周期的优化措施.非稳态静电收尘理论研究与实验研究表明,收尘效率对供电电压存在一最大值,且此最佳供电电压是随极板沉积粉尘层比电阻、粉尘层厚度等动态变化的;振打周期的长短与粉尘层比电阻有关.据此提出的运行参数优化结果表明,对于比电阻不同的粉尘,电除尘器收尘效率最高时对应的供电电压随粉尘层比电阻的增大而降低,对于同一粉尘,最佳供电电压随粉尘层厚度的增长而提高;粉尘层比电阻低于1011Ω·cm时,一般保持极板粉尘层厚度在3～5 mm以内为佳,对于高比电阻粉尘应寻求适宜的清灰方式保障极板处于清洁状态. 相似文献
602.
Organochlorine pesticides in surface sediments and suspended particulate matters from the Yangtze estuary, China 总被引：9，自引：0，他引：9
Liu M Cheng S Ou D Yang Y Liu H Hou L Gao L Xu S 《Environmental pollution (Barking, Essex : 1987)》2008,156(1):168-173
Total HCHs' and total DDTs' levels in surface sediments (SS) ranged from 0.5 to 17.5 ng g−1 and from 0.9 to 33.1 ng g−1, averaged 6.0 and 8.2 ng g−1, respectively. Total HCHs' and total DDTs' levels in suspended particulate matters (SPM) varied from 6.2 to 14.8 ng g−1 with a mean value of 12.3 ng g−1 and were from 3.4 to 25.7 ng g−1 with an average of 16.4 ng g−1, respectively. Lindane is the main HCHs' source and continuing use in the Yangtze Delta areas of ‘pure’ γ-HCH (lindane) rather than technical HCH (a mix of largely α- and some γ-HCH). DDTs in SS are mainly accumulated in history. However, high DDT fractions in SPM are indicators of new input of typical dicofol type DDT from 2002 to 2004. It can be seen that most samples from the Yangtze estuary were in ranges where adverse biological effects are expected, either occasionally or frequently. 相似文献
603.
不同面积小流域山洪泥石流预报模型研究——以北京市密云县为例 总被引：1，自引：0，他引：1
针对北京市密云县境内密云水库上游山洪泥石流发生特点,以系统科学为基本思想,将Bayes判别分析法引入山区小流域山洪泥石流预报模型建立之中。通过对北京市密云县境内密云水库上游影响山洪泥石流发生的系统内部要素和其外部环境条件进行综合分析,选择影响山洪泥石流发生的前15d实效降雨量和当日降雨量作为预报模型因子,分别建立了三种不同流域面积范围的山洪泥石流预报模型,所建立的山洪泥石流预报模型适用的流域面积范围分别为0.30～2.00 km2、2.00～5.00 km2和5.00～15.42 km2。经检验,三组预报模型的正确率分别为86.4%、92.9%和83.3%,均满足了Bayes判别分析法所规定的其验证正确率的要求,表明模型可以应用于研究区域不同流域面积范围的山洪泥石流预报。预报模型的建立为北京市密云县境内密云水库上游山洪泥石流的即时预报提供了一种简捷易行方法。 相似文献
604.
605.
对华北、西北和南方等地的30余所变电站产生的生活污水的处理及排放情况进行了调研,汇总分析了我国目前变电站主要的污水处理方法、排放方式及其存在的主要问题,并针对各地区的特点提出了相应的解决方案。 相似文献
606.
Zhongbin Lu Zhiguang Hou Xiumei Wang Siwei Wang Yanyan Shang Xing Yuan 《环境科学学报(英文版)》2010,22(11):1774-1778
HW-02 is a new organophosphates herbicide which is discovered and developed in China. The kinetics and mechanism of HW- 02 photodegradation in the organic solvents were studied at 25°C under the irradiation of ultraviolet light. The results showed that photochemical reaction of HW-02 in organic solvents such as n-hexane, methanol, dimethyl benzene and acetone under UV light could be well described by the first kinetic equation, and the photodegradation efficiency decreased with a order of n-hexane methanol xylene acetone. The photodegradation efficiency constant of HW-02 in n-hexane, methanol, xylene and acetone were 4.951 × 10 2 , 3.253 × 10 2 , 2.377 × 10 2 and 1.628 × 10 2 min 1 , and the corresponding half-lives were 13.99, 21.20, 29.15 and 42.56 min, respectively. By separation and identification of photoproducts using GC-MS, it could be concluded that HW-02 was photolyzed through ester cleavage, photo-dechlorination and photoisomerization of the molecule itself. 相似文献
607.
2008年5·12汶川地震灾难造成了重大的人员伤亡,本文将以<人民日报>作为研究样本,选取5月12日到6月12日共32天的报道,通过对抗震救灾报道进行归类、分析、思考,笔者认为<人民日报>在抗震救灾报道中呈现出议程设置进程化,议题选择多样化、报道公开透明有力等新的特点,充分体现了媒体的社会责任和社会功能,因此本次报道是中国媒体在突发事件报道中新的里程碑. 相似文献
608.
Cheng Liu Lijun Hou Min Liu Yanling Zheng Guoyu Yin Hongpo Dong Xia Liang Xiaofei Li Dengzhou Gao Zongxiao Zhang 《环境科学学报(英文版)》2020,32(7):91-97
Estuarine and intertidal wetlands are important sites for nitrogen transformation and elimination. However, the factors controlling nitrogen removal processes remain largely uncertain in the highly dynamic environments. In this study, continuous-flow experiment combined with 15N isotope pairing technique was used to investigate in situ rates of denitrification and anaerobic ammonium oxidation (anammox) and their coupling with nitrification in intertidal wetlands of the Yangtze Estuary. The measured rates varied from below the detection limit to 152.39 µmol N/(m2·hr) for denitrification and from below the detection limit to 43.06 µmol N/(m2·hr) for anammox. The coupling links of nitrogen removal processes with nitrification were mainly dependent on nitrate, organic carbon, sulfide, dissolved oxygen and ferric iron in the estuarine and intertidal wetlands. Additionally, it was estimated that the actual nitrogen removal processes annually removed approximately 5% of the terrigenous inorganic nitrogen discharged into the Yangtze Estuary. This study gives new insights into nitrogen transformation and fate in the estuarine and intertidal wetlands. 相似文献
609.
Meirong Zhao Chenyang Ji Yunkai Luo Jiawen Yang Yaoyao Dai Jiahui Miao Siqing Yue 《环境科学学报(英文版)》2023,35(5):603-614
Polyhalogenated carbazoles (PHCZs) have been widely accepted as emerging pollutants, whereas their ecological and health risks remain uncertain. Herein, female and male Sprague-Dawley (SD) mice were treated with four typical PHCZs to investigate their negative consequences, along with alternations in gut microbiota to indicate underlying mechanisms. In female mice, the relative liver weight ratio increased after four PHCZs exposure; 2-bromocarbazole (2-BCZ) increased urine glucose level; 3-bromocarbazole (3-BCZ) decreased the glucose and total cholesterol levels; 3,6-dichlorocarbazole (3,6-DCCZ) decreased glucose level. The only disturbed biochemical index in male mice was the promoted alkaline phosphatase (ALP) level by 3,6-DCCZ. We also found that the differential blood biochemical indices were correlated with gut microbiota. 3-BCZ and 3,6-DCCZ altered Bacteroidetes and Proteobacteria phyla in female and male mice, which were correlated with metabolic disorders. Our findings demonstrated the correlation between PHCZs induced potential hepatotoxicity and metabolic disorders may be due to their dioxin-like potentials and endocrine disrupting activities, and the gender differences might result from their estrogenic activities. Overall, data presented here can help to evaluate the ecological and health risks of PHCZs and reveal the underlying mechanisms. 相似文献
610.
中国危险废物集中处置设施建设现状、问题和对策 总被引：1，自引：0，他引：1
综合性危险废物集中处置设施的建设是实现危险废物安全处置和环境安全目标最根本的保障。本文对《全国危险废物和医疗废物处置设施建设规划》确定的建设项目目前的建设进展进行了全面分析,指出项目建设和运营中存在着布局、工艺技术、废物收集难、运营企业自身能力有待提高以及研发和产业化支撑能力差等五个方面的问题,反思中国过去五年时间里在危险废物和医疗废物处置和管理上取得的经验和教训,提出进一步推进项目建设和“十二五”期间加强危险废物和医疗废物管理的若干建议。 相似文献