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   6608篇
  免费   39篇
  国内免费   43篇
安全科学   144篇
废物处理   393篇
环保管理   601篇
综合类   800篇
基础理论   1836篇
环境理论   7篇
污染及防治   1931篇
评价与监测   543篇
社会与环境   424篇
灾害及防治   11篇
  2023年   46篇
  2022年   107篇
  2021年   159篇
  2020年   63篇
  2019年   65篇
  2018年   255篇
  2017年   257篇
  2016年   383篇
  2015年   160篇
  2014年   240篇
  2013年   390篇
  2012年   649篇
  2011年   483篇
  2010年   235篇
  2009年   161篇
  2008年   263篇
  2007年   303篇
  2006年   246篇
  2005年   534篇
  2004年   624篇
  2003年   490篇
  2002年   128篇
  2001年   87篇
  2000年   58篇
  1999年   58篇
  1998年   18篇
  1997年   22篇
  1996年   14篇
  1995年   30篇
  1994年   16篇
  1993年   10篇
  1992年   12篇
  1991年   14篇
  1990年   9篇
  1989年   5篇
  1988年   3篇
  1985年   6篇
  1984年   4篇
  1982年   4篇
  1978年   3篇
  1967年   5篇
  1966年   6篇
  1965年   2篇
  1964年   5篇
  1962年   3篇
  1961年   2篇
  1959年   4篇
  1958年   15篇
  1957年   6篇
  1955年   2篇
排序方式: 共有6690条查询结果,搜索用时 31 毫秒
81.
82.
In her recent article, “Does autonomy count in favor of labeling genetically modified food?,” Kirsten Hansen argues that in Europe, voluntary negative labeling of non-GM foods respects consumer autonomy just as well as mandatory positive labeling of foods with GM content. She also argues that because negative labeling places labeling costs upon those consumers that want to know whether food is GM, negative labeling is better policy than positive labeling. In this paper, we argue that Hansen’s arguments are mistaken in several respects. Most importantly, she underestimates the demands of respecting autonomy and overestimates the cost of positive labeling. Moreover, she mistakenly implies that only a small minority of people desire information about GM content. We also explore the extent to which her arguments would apply to the US context, and argue that any discussion of the relationship between autonomy and labeling should include not just considerations of consumer autonomy but also considerations of what we call citizen autonomy.  相似文献   
83.
Few moral arguments have been made against vegetarian diets. One exception is the “Logic of the Larder:” We do animals a favor by purchasing their meat, eggs, and milk, for if we did not purchase these products, fewer animals would exist. This argument fails because many farm animals have lives that are probably not worth living, while others prevent a significant number of wild animals from existing. Even if this were not so, the purchase of animal products uses resources that could otherwise be used to bring a much greater number of animals into existence.  相似文献   
84.
How do youth learn through participation in efforts to study and change the school food system? Through our participatory youth action research (YPAR) project, we move beyond the “youth as consumer” frame to a food justice youth development (FJYD) approach. We track how a group of youth learned about food and the public policy process through their efforts to transform their own school food systems by conducting a participatory evaluation of farm-to-school efforts in collaboration with university and community partners. We used the Photovoice research method, placing cameras in the hands of young people so that they themselves could document and discuss their concerns and perspectives. The research was designed to gain insight about youths’ knowledge of food, health, and community food systems. Drawing upon the youth group’s insights, we build a framework for building critical consciousness through FJYD.  相似文献   
85.
Environmental Science and Pollution Research - The assessment of productivity change over time and its drivers is of great significance for water companies and regulators when setting urban water...  相似文献   
86.
87.
88.
In general, tourism plays a significant role in the economy of archipelagos and islands. The Autonomous Region of the Azores has a great potential for tourism, offering multiple attractions, both natural and cultural, creating a big challenge for a sustainable tourism policy since little attention has been paid to the archipelagos and their special needs. This work aims to understand the profile and type of ecotourist that visits the Azores. This knowledge is of great importance for a better management and development of nature-based tourism, and products tailored to the needs and expectations of visitors. The data were collected by means of exit surveys conducted at the Airport of São Miguel Island, the larger and most populated island of the archipelago, during the high tourist season—July–September 2009. The analysis of the visitor’s profile and preferences is crucial to draw adequate strategies of management for tourism, while it helps to adequate the offer to the demand. Results showed that 41.1 % of the tourists claimed to be attracted to the islands due to their “natural values” (e.g., landscape, biodiversity, and geodiversity). The most practiced activities were whale-watching (32.4 %) and mountaineering/hiking (31.6 %), followed by diving (7 %) and other sports (5.1 %). The tourists’ profile points to a mainstream, soft, and incidental type of ecotourist. This information helps to develop and support a strategic planning and management, both at local and regional levels, for sustainable tourism policies.  相似文献   
89.
The use of recurrence plots have been extensively used in various fields. In this work, recurrence plots investigate the changes in the non-linear behaviour of urban air pollution using large datasets of raw data (hourly). This analysis has not been used before to extract information from large datasets for this type of non-linear problem. Two different approaches have been used to tackle this problem. The first approach is to show results according to monitoring network. The second approach is to show the results by particle type. This analysis shows the feasibility of using recurrence analysis for pollution monitoring and control.  相似文献   
90.

Can Gio district is located in the coastal area of Ho Chi Minh City, southern Vietnam. Discharge of wastewater from Ho Chi Minh City and neighboring provinces to the rivers of Can Gio has led to concerns about the accumulation of trace metals (As, Cu, Cr, Ni, Pb, and Zn) in the coastal sediments. The main objective of this study was to assess the distribution of As, Cu, Cr, Ni, Pb, and Zn in surface and core sediments and to evaluate the contamination status in relation to local background values, as well as the potential release of these selected trace metals from sediments to the water environment. Sediment characteristization, including determination of fine fraction, pH, organic matter, and major elements (Al, Fe, Ca, K, Mg, and S), was carried out to investigate which parameters affect the trace metal enrichment. Fine fraction and Al contents were found to be the controlling proxies affecting the distribution of trace metals while other sediment characteristics did not show any clear influence on trace metals’ distribution. Although As concentrations in the sediments were much higher compared to its reference value in other areas, the enrichment factor based on local background values suggests minor contamination of this element as well as for Cr, Cu, and Pb. Risk assessment suggested a medium to very high risk of Mn, Zn, and Ni under acidification. Of importance is also that trace metals in sediments were not easily mobilized by organic complexation based on their low extractabilities by ammonium-EDTA extraction.

  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