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   315篇
  免费   0篇
  国内免费   11篇
安全科学   9篇
废物处理   27篇
环保管理   17篇
综合类   28篇
基础理论   35篇
环境理论   1篇
污染及防治   156篇
评价与监测   36篇
社会与环境   17篇
  2023年   10篇
  2022年   58篇
  2021年   41篇
  2020年   12篇
  2019年   15篇
  2018年   14篇
  2017年   22篇
  2016年   14篇
  2015年   12篇
  2014年   18篇
  2013年   27篇
  2012年   9篇
  2011年   15篇
  2010年   12篇
  2009年   8篇
  2008年   7篇
  2007年   9篇
  2006年   2篇
  2005年   1篇
  2004年   2篇
  2003年   1篇
  2002年   2篇
  2000年   2篇
  1999年   1篇
  1997年   1篇
  1992年   1篇
  1990年   1篇
  1985年   2篇
  1984年   1篇
  1980年   1篇
  1979年   2篇
  1972年   1篇
  1964年   1篇
  1963年   1篇
排序方式: 共有326条查询结果,搜索用时 312 毫秒
61.
Environmental Science and Pollution Research - Coronavirus refers to a group of widespread viruses. The name refers to the specific morphology of these viruses because their spikes look like a...  相似文献   
62.
‘Metal ash’ presents a waste disposal problem in most of the developing countries as the industries employ obsolete technologies. In this paper we describe analysis of tin ash, zinc ash and aluminium ash by means of optical methods, such as X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS), electron probe micro analysis (EPMA), scanning electron microscopy (SEM) and chemical methods. The results of tin ash obtained by XRD method matched well with the cassiterite, a naturally occurring mineral of tin. ICP-MS studies reveal the presence of a large number of tracer metals, which may cause pollution by tertiary dispersion and this aspect is discussed. Conversely, the data generated by chemical methods are limited. However, the methods are simple and cost-effective. Then, they can easily be adopted by low-budget industries. Simple and cost-effective process to recover tin from tin ash is described. It is based on heating tin ash with sodium cyanide to about 900°C to separate tin component from the metal ash. The process recovers good quality tin and offers a very high yield. The process can be scaled up to small pilot plant.  相似文献   
63.
64.
Environmental Economics and Policy Studies - We capitalize on access to plant-level data in examining the changes in emissions of biochemical oxygen demand (BOD), total suspended solids (TSS), and...  相似文献   
65.
The present study examines whether patient-perpetrated violence triggers anger, hatred and other negative emotions that, under certain circumstances, might motivate nurses to behave violently with patients. In doing so, this study considers burnout as a mediator in the patient violence–nurse violence relationship. To test the causal paths, data were collected from 182 nurses working in two government-sector teaching hospitals of Pakistan's Punjab province. Results confirm that patient violence toward nurses leads to nurse violence toward patients through the mediating effect of burnout. The study advises hospitals to provide wellness and stress management programs to nurses who regularly experience events involving patient violence. Hospitals may consider allowing nurses to take short breaks after an encounter with violently behaving patients. In addition, hospitals should conduct empathy-promoting training, emotional intelligence training and ‘lens of the patient’ training programs to sensitize their nursing staff.  相似文献   
66.
Environmental Science and Pollution Research - This study was designed to investigate the impact of meteorological indicators (temperature, rainfall, and humidity) on total COVID-19 cases in...  相似文献   
67.
The toxicity of acephate to four species of aquatic insects, as well as the metabolism and cholinesterase-inhibiting properties of the chemical in the rat were studied. The results indicated that mayfly larvae were very sensitive to the toxic effects of acephate, whereas larvae of the stonefly, damselfly and mosquito were much less sensitive. In the rat, orally-administered acephate was rapidly absorbed from the intestines and severely inhibited the cholinesterases in the blood and brain. The enzymes began to recover after 24 hours, while the chemical was completely eliminated within three days. The amount of methamidophos observed in the liver was extremely low. The cholinesterase-inhibiting properties of acephate and methamidophos were compared in vitro to that of paraoxon, a known strong anticholinesterase. Enzymes from four vertebrates were used. In all cases, except one, acephate was found to be six orders of magnitude weaker than paraoxon, whereas methamidophos was three orders weaker. Trout brain cholinesterase was the exception; it was as sensitive to paraoxon as it was to methamidophos. Finally, four cholinesterases were inhibited with methamidophos, and their ability to reactivate spontaneously or to recover by induction with pyridine aldoxime methiodide (PAM) in vitro were determined. The results suggested that methamidophos-inhibited cholinesterases did not reactivate spontaneously; instead the enzymes remained inhibited either in a phosphorylated or an aged state. The significance of these results are discussed in relation to the use of acephate for forest insect pests.  相似文献   
68.
Lime mud is a kind of solid waste in the papermaking industry, which has been a source of serious environmental pollution. Ceramsites containing anorthite and gehlenite were prepared from lime mud and fly ash through the solid state reaction method at 1050°C. The objective of this study was to explore the efficiency of Ca2 + and OH release and assess the phosphorus and copper ion removal performance of the ceramsites via batch experiments, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that Ca2 + and OH were released from the ceramsites due to the dissolution of anorthite, gehlenite and available lime. It is also concluded that gehlenite had stronger capacity for Ca2 + and OH release compared with anorthite. The Ca2 + release could be fit well by the Avrami kinetic model. Increases of porosity, dosage and temperature were associated with increases in the concentrations of Ca2 + and OH released. Under different conditions, the ceramsites could maintain aqueous solutions in alkaline conditions (pH = 9.3–10.9) and the release of Ca2 + was not affected. The removal rates of phosphorus and copper ions were as high as 96.88% and 96.81%, respectively. The final pH values of both phosphorus and copper ions solutions changed slightly. The reuse of lime mud in the form of ceramsites is an effective strategy.  相似文献   
69.
Abstract

Paper electrophoretic movements of a number of pesticides belonging to organophosphorus, organochlorine and pyethroid groups in various acid background electrolytes have been studied. The effect of pH and pKa of the acids on the movement of these pesticides have also been studied. It has been observed that the movement of most of the pesticides is enhanced with increase in the degree of ionisation of the acids (pKa) studied as background electrolytes. The movement also increases with increase in the pH of acids. On the basis of differential movement of pesticides towards cathode and anode, a number of separations have been achieved from binary mixtures. Monocrotophos, rogor and malathion have been determined quantitatively (28.6 ‐ 29.2 μg) in alcoholic extracts of soil samples.  相似文献   
70.
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