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   251406篇
  免费   15947篇
  国内免费   39672篇
安全科学   23318篇
废物处理   11552篇
环保管理   28804篇
综合类   103343篇
基础理论   47347篇
环境理论   211篇
污染及防治   54357篇
评价与监测   16419篇
社会与环境   14771篇
灾害及防治   6903篇
  2024年   848篇
  2023年   3949篇
  2022年   9421篇
  2021年   9460篇
  2020年   8903篇
  2019年   7111篇
  2018年   8305篇
  2017年   10071篇
  2016年   10140篇
  2015年   9426篇
  2014年   11307篇
  2013年   20863篇
  2012年   16075篇
  2011年   17920篇
  2010年   15690篇
  2009年   15459篇
  2008年   15857篇
  2007年   15543篇
  2006年   14470篇
  2005年   11174篇
  2004年   8539篇
  2003年   7549篇
  2002年   6663篇
  2001年   6115篇
  2000年   5196篇
  1999年   3548篇
  1998年   2386篇
  1997年   2180篇
  1996年   2207篇
  1995年   2289篇
  1994年   2023篇
  1993年   1489篇
  1992年   1502篇
  1991年   1363篇
  1990年   1251篇
  1989年   1145篇
  1988年   1013篇
  1987年   906篇
  1986年   859篇
  1985年   870篇
  1984年   895篇
  1983年   824篇
  1982年   918篇
  1981年   817篇
  1980年   627篇
  1979年   686篇
  1978年   585篇
  1977年   513篇
  1975年   467篇
  1974年   461篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Fifty percent of the dry zone areas in Sri Lanka have fluoride levels above 1 ppm. This paper discusses the ground conditions and recommends an appropriate range of fluoride in drinking water which can support preventive practices for improving the oral health of children 8-years old and younger. In efforts to address the Chronic Kidney Disease of Unknown etiology (CKDU), water treatment to reduce contaminant level in potable water has been implemented. Such treatment would also remove fluoride and has resulted in potable water with various fluoride levels, depending on concentrations in the raw water. While it is important to reduce fluoride levels, it is important to have appropriate residual levels for prevention of dental caries. It needs, however, to be noted fluoride in excess can cause dental fluorosis. In Sri Lanka's dry zone areas increasing prevalence of dental fluorosis with decreasing prevalence of dental caries has been noted. Consumption of tea and powdered milk could increase total intake of fluoride. Fluoridated toothpaste, when used properly, may, however, result in negligible intake of fluoride. Sri Lanka's hot tropical climate which results in substantial intake of fluids reinforces the need to consider reduction in water fluoride. Consideration of local studies and international standards indicate fluoride levels should be in the range of 0.225–0.500 ppm. In the range of 0.225–0.500 ppm, the prevalence of dental fluorosis and caries was only 14% and 8%, respectively, in an endemic district. When fluoride levels are above 0.500 ppm, the issue of dental fluorosis shall need to be addressed. When levels are below 0.225 ppm, oral health care services shall need to be directed at preventing dental caries.  相似文献   
82.
Tang  Zhi  Li  Yilian  Yang  Zhe  Liu  Danqing  Tang  Min  Yang  Sen  Tang  Ye 《Environmental science and pollution research international》2019,26(20):20277-20285
Environmental Science and Pollution Research - The sorption/desorption behaviors of benzene, toluene, ethylbenzene, and xylene (BTEX) on soil organic matter (SOM) have a significant influence on...  相似文献   
83.
Environmental Science and Pollution Research - Toxic cyanobacterial blooms (TCBs) have become a growing concern worldwide. The present study investigated the dynamic of toxic cyanobacteria and...  相似文献   
84.
Environmental Science and Pollution Research - Behavior responses of organisms can be used as a non-invasive method for neurotoxicology studies since it directly links the nervous system’s...  相似文献   
85.
Environmental Science and Pollution Research - Zinc is an essential nutritional trace mineral required for growth and health. The aim of the current work is to compare the effects of bulk zinc...  相似文献   
86.
Environmental Science and Pollution Research - Nylon powders are a type of microplastic (MP) used in personal care products such as cosmetics and sunscreens. To determine the effects of nylon...  相似文献   
87.
Waste accumulation is a grave concern and becoming a transboundary challenge for environment. During Covid-19 pandemic, diverse type of waste were collected due to different practices employed in order to fight back the transmission rate of the virus. Covid-19 was proved to be capricious catastrophe of this 20th century and even not completely eradicated from the world. The havoc created by this imperceptible quick witted, pleomorphic deadly virus can't be ignored. Though a number of vaccines have been developed by the scientists but there is a fear of getting this virus again in our life. Medical studies prove that immunity drinks will help to reduce its reoccurrences. Coconut water is widely used among all drinks available globally. Its massive consumption created an incalculable pile of green coconut shells around the different corners of the world. This practice generating enormous problem of space acquisition for the environment. Both the environment and public health will benefit from an evaluation of quantity of coconut waste that is being thrown and its potential to generate value added products. With this context, present article has been planned to study different aspects like, coconut waste generation, its biological properties and environmental hazards associated with its accumulation. Additionally, this review illustrates, green technologies for production of different value added products from coconut waste.  相似文献   
88.

Community-based approaches are pursued in recognition of the need for place-based responses to environmental change that integrate local understandings of risk and vulnerability. Yet the potential for fair adaptation is intimately linked to how variations in perceptions of environmental change and risk are treated. There is, however, little empirical evidence of the extent and nature of variations in risk perception in and between multiple community settings. Here, we rely on data from 231 semi-structured interviews conducted in nine communities in Western Province, Solomon Islands, to statistically model different perceptions of risk and change within and between communities. Overall, people were found to be less likely to perceive environmental changes in the marine environment than they were for terrestrial systems. The distance to the nearest market town (which may be a proxy for exposure to commercial logging and degree of involvement with the market economy), and gender had the greatest overall statistical effects on perceptions of risk. Yet, we also find that significant environmental change is underreported in communities, while variations in perception are not always easily related to commonly assumed fault lines of vulnerability. The findings suggest that there is an urgent need for methods that engage with the drivers of perceptions as part of community-based approaches. In particular, it is important to explicitly account for place, complexity and diversity of environmental risk perceptions, and we reinforce calls to engage seriously with underlying questions of power, culture, identity and practice that influence adaptive capacity and risk perception.

  相似文献   
89.
90.
The purpose of the research is to identify the critical challenges that are impeding the adoption of e-mobility in India. It also aims to give a roadmap how to address these challenges while taking into considerations concerns of all the relevant stakeholders. Based on an in-depth literature review, an exploratory research design is employed to delve deep into various aspects of e-mobility. This is followed by a three-phase Delphi technique to identify and rate the e-mobility challenges in the Indian context. The study successfully identifies four different categories of challenges and proposes integrative framework for e-mobility. Further, the research goes on to lay out the future roadmap for mass adoption of electric vehicles (EVs) in India. The research is novel in terms of presenting a holistic viewpoint on e-mobility in India. Its originality lies in identifying the major inhibitors obstructing EVs adoption in India and then suggesting the roadmap how to overcome these impediments for mass adoption of e-mobility.  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