全文获取类型
收费全文 | 1449篇 |
免费 | 170篇 |
国内免费 | 778篇 |
专业分类
安全科学 | 136篇 |
废物处理 | 92篇 |
环保管理 | 184篇 |
综合类 | 1314篇 |
基础理论 | 147篇 |
污染及防治 | 375篇 |
评价与监测 | 48篇 |
社会与环境 | 62篇 |
灾害及防治 | 39篇 |
出版年
2024年 | 5篇 |
2023年 | 12篇 |
2022年 | 36篇 |
2021年 | 34篇 |
2020年 | 42篇 |
2019年 | 56篇 |
2018年 | 46篇 |
2017年 | 51篇 |
2016年 | 89篇 |
2015年 | 89篇 |
2014年 | 117篇 |
2013年 | 125篇 |
2012年 | 163篇 |
2011年 | 134篇 |
2010年 | 115篇 |
2009年 | 125篇 |
2008年 | 112篇 |
2007年 | 179篇 |
2006年 | 161篇 |
2005年 | 126篇 |
2004年 | 107篇 |
2003年 | 84篇 |
2002年 | 77篇 |
2001年 | 72篇 |
2000年 | 64篇 |
1999年 | 44篇 |
1998年 | 28篇 |
1997年 | 29篇 |
1996年 | 20篇 |
1995年 | 14篇 |
1994年 | 18篇 |
1993年 | 12篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
排序方式: 共有2397条查询结果,搜索用时 15 毫秒
951.
952.
953.
Sludge reduction with Tubificidae and the impact on the performance
of the wastewater treatment process 总被引:4,自引:0,他引:4
To reduce excess sludge, a Tubificidae reactor was combined with an integrated oxidation ditch with vertical circle (IODVC), and a new integrated system was developed for wastewater treatment. A pilot-scale of this integrated system was tested to investigate the sludge reduction with Tubificidae and the impact on effluent quality and sludge production. The dominant worm was Branchnria Sowerbyi in the Tubificidae reactor after inoculation of Branchnria Sowerbyi and Limnodrilns sp., and the maximal volume density of wet Tubificidae in vessels of the Tubificidae reactor was 17600 g/m3. Two operational modes, treating the excess sludge (first mode) and the returned sludge (second mode) of IODVC by the Tubificidae reactor, were used in this experiment. The results showed that the excess sludge reduction rate was 46.4% in the first mode, and the average sludge yield of the integrated system was 6.19×10-5 kg SS/kg COD in the second mode. Though the sludge returned to IODVC via the Tubificidae reactor, it had little impact on the effluent quality and the sludge characteristics of the IODVC. No new type of recalcitrant substance in the supernatant was discharged into the environment when the sludge was treated by Tubificidae. The experimental results also indicated that no significant changes occurred on the viscosity, specific resistance, and the floc size distribution of the sludge. 相似文献
954.
Evaluation of oasis ecosystem risk by reliability theory in an arid area: A case study in the Shiyang River Basin, China 总被引:2,自引:0,他引:2
Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows: the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis's ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis's area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area. 相似文献
955.
浅论循环经济与环境污染综合治理 总被引:4,自引:0,他引:4
介绍循环经济的主要特征及其对环境、资源的有利影响,指出化工企业的发展应走新型工业化道路。 相似文献
956.
紫外光催化氧化技术处理有机污染物的研究动态 总被引:5,自引:1,他引:5
主要介绍了北美先进的紫外光催化氧化技术对有机废水、废气的处理研究与应用,简要介绍三种类型光催化反应器的结构。该技术在国外处于研究阶段,预期应用前景很好,尤其适用于电力充沛地区有机废水、废气的处理,具有应用方便、处理效果好,投资费用低等特点。 相似文献
957.
冲突分析在环境领域中的应用 总被引:2,自引:0,他引:2
冲突分析是用来分析冲突局势、预测冲突发展、研究、设计冲突处理方案的一门科学。本文根据国内外研究资料,分析了冲突分析在环境领域中的应用,其中对公共设施选址、污染集中治理投资的分摊、允许排污量在各排污口问的公平分配、水资源集中管理、协调度模型处理环境与经济的冲突、跨行政区河流边界水质标准的确定、资源的开发与保护等进行了重点评述,并指出了冲突分析理论中存在的问题、解决的办法和发展方向。 相似文献
958.
IntroductionBecauseofthehighoxidationpotentialofozone(O3) ,ozonationhasbeenregardedasapromisingmethodfordrinkingandwastewatertreatment.AwiderangeoforganicpollutantsinwatercanbedegradedbyO3,O3combinedwithH2 O2 orUVlight,whichareknownasAdvancedChemicalOxidati… 相似文献
959.
SBR法处理高浓度有机废水试验研究 总被引:2,自引:0,他引:2
采用序批式活性污泥法(SBR),对处理高浓度化工废水进行了实验研究,结果表明,温度是影响SBR法处理效果的一处重要因素,其次是pH值、曝气量和周期,并在一定条件下,可得到75%的CODcr去除率。 相似文献
960.