全文获取类型
收费全文 | 613篇 |
免费 | 42篇 |
国内免费 | 172篇 |
专业分类
安全科学 | 31篇 |
废物处理 | 15篇 |
环保管理 | 116篇 |
综合类 | 483篇 |
基础理论 | 47篇 |
污染及防治 | 96篇 |
评价与监测 | 16篇 |
社会与环境 | 19篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 16篇 |
2021年 | 23篇 |
2020年 | 17篇 |
2019年 | 13篇 |
2018年 | 16篇 |
2017年 | 14篇 |
2016年 | 33篇 |
2015年 | 27篇 |
2014年 | 29篇 |
2013年 | 48篇 |
2012年 | 63篇 |
2011年 | 83篇 |
2010年 | 51篇 |
2009年 | 64篇 |
2008年 | 32篇 |
2007年 | 55篇 |
2006年 | 62篇 |
2005年 | 31篇 |
2004年 | 37篇 |
2003年 | 28篇 |
2002年 | 17篇 |
2001年 | 14篇 |
2000年 | 17篇 |
1999年 | 12篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有827条查询结果,搜索用时 109 毫秒
821.
ABR+复合人工湿地处理农村生活污水中试 总被引:2,自引:0,他引:2
采用ABR+复合人工湿地组合工艺对农村分散型生活污水进行中试研究。试验期间进水pH和温度的范围分别为:6.5~8.5,14.0~23.5℃。结果表明:ABR在HRT为10 h,COD容积负荷为0.52 kg/(m3.d)(复合人工湿地面积负荷为0.018 kg/(m2.d))的条件下,系统对COD、NH3-N、TN、TP和浊度的平均去除率分别为:78%、64%、60%、63%和80%;出水平均质量浓度分别为:47,7.13,13.31,0.67 mg/L,浊度为10 NTU;系统运行24 d后,ABR反应器中观察到厌氧颗粒污泥。 相似文献
822.
以生活污水培养驯化污泥的小试规模氧化沟工艺为研究对象,进行了混合液回流比为100%、200%和300%时对反硝化除磷的影响研究。结果表明:在试验条件下,混合液回流比对TP去除效果影响不大,但去除途径不同,当混合液回流比为200%和300%时,TP主要是在缺氧区通过反硝化除磷去除的,而混合液回流比为100%时,TP主要是在好氧区去除的;随着混合液回流比增加,NH+4-N和TN去除率也有所增加。在混合液回流比为200%时,系统脱氮除磷效果最好,出水TP和TN去除率分别达到93.9%和82.6%,且NO-3-N可以在缺氧区作为电子受体提供给反硝化除磷。从控制运行能耗和反硝化除磷的角度综合考虑,混合液回流比控制在200%是较适宜的。 相似文献
823.
无土栽培植物对农村生活污水的净化特性研究 总被引:4,自引:0,他引:4
选取水烛、石菖蒲和黄菖蒲三种挺水植物作为无土栽培系统的培养物,通过动态试验进行农村生活污水处理对比研究。结果表明:相对对照系统,三种植物对农村生活污水均具有较好的适应性,生长量石菖蒲>黄菖蒲>水烛;处理系统对COD、NH+4-N和TN的去除效果依次为石菖蒲>黄菖蒲>水烛>对照;对TP的去除率依次为水烛>黄菖蒲>石菖蒲>对照。同时,通过对处理系统去除氮磷途径的分析,发现植物吸收作用是主要去除方式,沉淀吸附也起着重要的作用。综合三种植物的净化能力,认为石菖蒲更适合无土栽培处理系统。 相似文献
824.
William J. Smith Claudio S. Quilodrán Michał T. Jezierski Ashley T. Sendell-Price Sonya M. Clegg 《Conservation biology》2022,36(3):e13867
Domestic animals have immense economic, cultural, and practical value and have played pivotal roles in the development of human civilization. Many domesticates have, among their wild relatives, undomesticated forms representative of their ancestors. Resurgent interest in these ancestral forms has highlighted the unclear genetic status of many, and some are threatened with extinction by hybridization with domestic conspecifics. We considered the contemporary status of these ancestral forms relative to their scientific, practical, and ecological importance; the varied impacts of wild–domestic hybridization; and the challenges and potential resolutions involved in conservation efforts. Identifying and conserving ancestral forms, particularly with respect to disentangling patterns of gene flow from domesticates, is complex because of the lack of available genomic and phenotypic baselines. Comparative behavioral, ecological, and genetic studies of ancestral-type, feral, and domestic animals should be prioritized to establish the contemporary status of the former. Such baseline information will be fundamental in ensuring successful conservation efforts. 相似文献
825.
826.
In this study, we suggested a criterion of Korean resource productivity calculation method including its range which is not generalized yet and analyzed its level by reviewing the resource productivity management policies and study trends of the major advanced countries. The material flow indexes that are widely used in major advanced countries, such as the domestic material consumption (DMC), were used to establish the resource productivity calculation method with estimation the domestic resource productivity during 2000–2010. As of 2010, the DMC was 590 million ton, GDP was 1 trillion dollars and DMC-based resource productivity was 1.75 thousand US dollars/ton, which was continuously increased during last ten years with 8.0%, 50.0%, and 38.9%, respectively. This increase tendency was not because of DMC reduction through resource management but because of just large GDP increase. The results of the comparison with other countries indicated that Korea had the lower resource productivity level and also the lower increasing rate than major advanced countries such as the UK and Japan, and required an efficient resource management plan for improvement. Therefore, we finally suggested a Korean resource productivity policy direction to construct its sustainable system for its improvement. 相似文献
827.