首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   240篇
  免费   3篇
  国内免费   5篇
安全科学   12篇
废物处理   28篇
环保管理   19篇
综合类   27篇
基础理论   25篇
污染及防治   93篇
评价与监测   29篇
社会与环境   13篇
灾害及防治   2篇
  2023年   3篇
  2022年   32篇
  2021年   17篇
  2020年   14篇
  2019年   6篇
  2018年   7篇
  2017年   10篇
  2016年   8篇
  2015年   7篇
  2014年   15篇
  2013年   33篇
  2012年   7篇
  2011年   13篇
  2010年   8篇
  2009年   4篇
  2008年   10篇
  2007年   12篇
  2006年   9篇
  2005年   1篇
  2004年   4篇
  2003年   7篇
  2002年   6篇
  2000年   1篇
  1999年   2篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1991年   1篇
  1990年   1篇
  1988年   2篇
  1984年   1篇
  1982年   1篇
  1978年   1篇
  1963年   1篇
排序方式: 共有248条查询结果,搜索用时 30 毫秒
211.
This article considers the evidence for threshold effects in the relationship between electricity and emission-permit prices in France and Germany during the second phase of the EU ETS. Specifically, we compare linear and non-linear threshold models of electricity prices using the sample-splitting and threshold estimation approach in Hansen (Econometrica, 64 575–603 2000). We find evidence of non-linear threshold effects in both countries. The estimated carbon-price thresholds are 14.94€ and 12.57€ in France and Germany respectively. The carbon-price threshold in France perfectly matches the well-known carbon spot-price structural break of October 2008. This is not the case for the carbon-price threshold in Germany. Further analysis reveals that carbon prices before October 2008 were not reflected in electricity prices in either country. This is mainly due to uncertainty about the future of the EU ETS that led electricity producers to adopt a wait-and-see attitude. After October 2008, French electricity producers passed the price of emission permits through to electricity prices in a linear way, while their German counterparts did so non-linearly. Finally, we suggest improvements to the design of the EU ETS. Our recommendations are to strengthen the price signal to make it more clear and reliable and provide sufficient incentives for energy transition.  相似文献   
212.
Environmental Science and Pollution Research - Enteric viruses, generally found in sewage, are recognized as the main cause of waterborne and foodborne public health outbreaks. Among leading...  相似文献   
213.
Environmental Science and Pollution Research - Multiple drug resistance and increased side effects due to allopathic drugs has warned scientific community with a global alarm to identify molecules...  相似文献   
214.
Environmental Science and Pollution Research - Tramadol abuse is an increasingly alarming phenomenon among Egyptian Community especially among workers and drivers. Study profile and factors...  相似文献   
215.
Enormous amounts of seawater are desalted everyday worldwide. The total world production of fresh water from the sea is about 2621 mgd (9.92 million m3 day-1 1985 figures). Desalting processes are normally associated with the rejection of high concentration waste brine from the plant itself or from the pretreatment units as well as during the cleaning period. In thermal processes, mainly multistage flash (MSF) thermal pollution occurs. These pollutants increase the seawater temperature, salinity, water current and turbidity. They also harm the marine environment, causing fish to migrate while enhancing the presence of algae, nematods and tiny molluscus. Sometimes micro-elements and toxic materials appear in the discharged brine.This paper will discuss the impact of the effluents from the desalination plants on the seawater environment with particular reference to the Saudi desalination plants, since they account for about 50% of the world desalination capacity.  相似文献   
216.
In this study, colemanite was recovered from tailings produced by the Kestelek (Turkey) Processing Plant by magnetic separation. Magnetic susceptibility measurements revealed that colemanite is diamagnetic in character whereas gangue minerals are weakly paramagnetic, apparently due to the presence of the iron-bearing silicates such as smectite and, to a less extent, illite. Three-stage magnetic separation tests were performed on the size fractions coarser than 75 microm produced from the tailings (31.52% B(2)O(3)) using a high-intensity permanent magnetic separator. Under the test conditions a colemanite concentrate with a B(2)O(3) content of 43.74% at 95.06% recovery was shown to be produced from the tailings. The mineralogical composition of the tailings appears to allow the removal of gangue minerals by magnetic separation and hence the production of a concentrate of commercial grade.  相似文献   
217.
218.
219.
A field experiment was conducted to investigate the effect of chicken manure compost on the fractionation of cadmium (Cd), soil biological properties and Cd uptake by wheat in a soil affected by mining activities in Hubei province, China. Compost was applied at five levels (0, 27, 54, 108, 216 t ha?1), and winter wheat (Triticum aestivum L.) was chosen as an indicator plant. Results showed that the application of compost increased soil pH and the content of total phosphorus and organic matter. Soil biological properties such as microbial biomass carbon, invertase, protease, urease and catalase activities were significantly enhanced by 0.24–3.47 times after compost application. Sequential extraction indicated that compost amendments decreased the acid-extractable Cd by 8.2–37.6 %, while increased the reducible and oxidisable Cd by 9.2–39.5 and 8.2–60.4 %, respectively. The addition of 27–54 t ha?1 compost reduced Cd content in wheat stems and seeds by 69.6–75.0 % and 10.3–18.4 %, respectively. However, only 25.5–26.5 % reductions in Cd content in wheat stems were observed in 108–216 t ha?1 compost amendments, and no significant decrease was detected for seeds. This study suggests that although compost is a suitable organic amendment to improve soil fertility and biological activities, the addition of compost should be moderated by an appropriate rate to optimize the use of compost for the reclamation of metal-contaminated soils at field scale.  相似文献   
220.
Dose and treatment-duration neurotoxic effects are reported for artemisinin drugs of mostly the liposoluble derivatives; and yet artemether, the only parenteral formulation of the artemisinin series available in Nigeria is fat-soluble and also has a treatment-duration of 5–7 days (in an attempt to delay recrudescence). Since parenteral drugs are usually resorted to in severe/complicated or multidrug-resistant malaria against the oral artemisinin co-formulated therapies (ACT), this study is aimed to investigate the pathological changes on selected tissues (if any), in rats, of the normal 7-days artemether-injections when used both in the normal and higher doses. Artemether was administered i.p., at three dose levels, equivalent to therapeutic dose (1.5 mg kg?1) as well as 5 and 10 times higher (7.5 and 15 mg kg?1). A three percentage v/v Tween 80 vehicle was used for the control experiment. The pathological changes in the kidney, heart, liver, and lungs evaluated using percentage mean organ:body-weight ratio showed no changes in the organs. No histopathological effect was observed in the organs of rats treated with 1.5 mg kg?1. However, rats treated with 7.5 and 15 mg kg?1 revealed necrositic lesions with mononuclear cellular-infiltration in the liver and brain. The liver had focal area necrosis, while the brain had liquefactive necrosis, neuronal degeneration, congested blood vessels, hemorrhage, and vacuolations. The interstitial spaces of the glomerulus and renal tubules of one kidney from rats that received 15 mg kg?1 had focal area fibrositic-necrosis.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号