全文获取类型
收费全文 | 44420篇 |
免费 | 497篇 |
国内免费 | 345篇 |
专业分类
安全科学 | 1386篇 |
废物处理 | 2066篇 |
环保管理 | 5963篇 |
综合类 | 7028篇 |
基础理论 | 11969篇 |
环境理论 | 18篇 |
污染及防治 | 10989篇 |
评价与监测 | 2973篇 |
社会与环境 | 2582篇 |
灾害及防治 | 288篇 |
出版年
2022年 | 347篇 |
2021年 | 416篇 |
2020年 | 276篇 |
2019年 | 330篇 |
2018年 | 595篇 |
2017年 | 654篇 |
2016年 | 1002篇 |
2015年 | 728篇 |
2014年 | 1150篇 |
2013年 | 3601篇 |
2012年 | 1395篇 |
2011年 | 1892篇 |
2010年 | 1553篇 |
2009年 | 1603篇 |
2008年 | 1945篇 |
2007年 | 1925篇 |
2006年 | 1720篇 |
2005年 | 1526篇 |
2004年 | 1468篇 |
2003年 | 1418篇 |
2002年 | 1338篇 |
2001年 | 1616篇 |
2000年 | 1160篇 |
1999年 | 690篇 |
1998年 | 548篇 |
1997年 | 585篇 |
1996年 | 603篇 |
1995年 | 707篇 |
1994年 | 617篇 |
1993年 | 555篇 |
1992年 | 564篇 |
1991年 | 553篇 |
1990年 | 544篇 |
1989年 | 524篇 |
1988年 | 482篇 |
1987年 | 427篇 |
1986年 | 397篇 |
1985年 | 401篇 |
1984年 | 461篇 |
1983年 | 416篇 |
1982年 | 474篇 |
1981年 | 395篇 |
1980年 | 311篇 |
1979年 | 348篇 |
1978年 | 309篇 |
1977年 | 267篇 |
1975年 | 251篇 |
1974年 | 251篇 |
1973年 | 288篇 |
1972年 | 261篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
141.
Epidemiological procedures can be organised under disaster conditions by means of a simple surveillance system and with few personnel.
In the aftermath of the 4 February 1976 earthquake in Guatemala, an information system was organized by which the requisite information for decision-making was obtained with adequate speed and promptness.
The initial epidemiologic informution was based on reports collected during the early days on symptoms observed at hospitals and health centers and in localities and villages in the stricken area.
At a second, post-emergency stage a more elaborate surveillance system was instituted to provide guidance in the investigntwn of outbreaks, evaluate the health activities and establish basic criteria for preventive and control measures. 相似文献
In the aftermath of the 4 February 1976 earthquake in Guatemala, an information system was organized by which the requisite information for decision-making was obtained with adequate speed and promptness.
The initial epidemiologic informution was based on reports collected during the early days on symptoms observed at hospitals and health centers and in localities and villages in the stricken area.
At a second, post-emergency stage a more elaborate surveillance system was instituted to provide guidance in the investigntwn of outbreaks, evaluate the health activities and establish basic criteria for preventive and control measures. 相似文献
142.
The results of recent IAEA intercomparison programs are reviewed. 相似文献
143.
J.M.R. Hutchinson 《Environment international》1980,3(5):363-364
The development of traceability in low-level radioactivity measurements is discussed. The role that the development of large quantities of natural matrix standards can play is also discussed. 相似文献
144.
Although oil spill cleanup requirements have existed in the United States for years, recent increases in oil imports and marine transportation of petroleum products as well as growing environmental concern have exposed a new industry, the Oil Spill Cleanup Industry. This paper explores some of the microeconomic aspects of this industry which has come under increased scrutiny by the general public, big business, and the federal government.In addition to a brief history and definition, several basic questions about the economic viability of the oil spill cleanup industry are raised and explored, and the impact on the industry of cleanup from government sources is examined, both from the perspective of present operations and from apparent future increases in federal participation. The primary dilemma facing the industry, that of providing continued and immediate supply while confronted with stochastic demand, is discussed. The effects of the large spill on the industry both in terms of revenue and ability to meet cleanup requirements is also considered.Information for the paper is drawn from past and continuing involvement in the U.S. Coast Guard's Marine Environmental Protection Program by both authors. The statistical evidence presented here was compiled through personal interviews and from two computerized Coast Guard information systems; PIRS (the Pollution Incident Reporting System), and SKIM (the Spill Cleanup Equipment Inventory System). 相似文献
145.
146.
V. A. OVCHARENKO 《Natural resources forum》1980,4(3):277-290
Natural gas may provide a major contribution to the world energy supply during the next few decades. The developing countries command about 50 per cent of the world proved natural gas reserves, with gas accounting for only 6 per cent of commercial primary energy production. The challenging task of expanding gas production and utilization in the developing countries, especially through effective use of gas associated with petroleum deposits and transportation of gas in liquefied form (LNG), will require long-term technical co-operation policy commitments with regard to investment, manpower and the transfer of technology. The article is intended to analyse the basic factors involved in these problems. Au cours des prochaines décennies, le gaz naturel peut constituer un apport considérable à l'approvisionnement énergétique mondial. Les pays en développement détiennent approximativement 50 pour cent des réserves mondiales prouvées de gaz naturel, le gaz représentant seulement 6 pour cent de la production d'énergie primaire commerciale. Le défi lancé par la production et l'utilisation croissantes de gaz dans les pays en développement, particulièrement par l'utilisation efficace du gaz lié aux gisements de pétrole et le transport du gaz liquéfié (GNL), requiert des engagements à long terme en matière de politique de coopération technique dans le domaine des investissements, de la main-d'oeuvre et du transfert de technologie. Cet article a pour but d'analyser les facteurs fondamentaux à prendre en considération lorsqu'on traite de ces problèmes. El gas natural podría representar una gran contribucíon a la oferta mundial de energía dentro de las próximas décadas. Los países en desarrollo poseen cerca del 50 porciento de la reserva provada mundial de gas y solamente el 6 porciento de la producción primaria de energía comercial proviene del gas. La tarea de expandir la producción y utilización de gas en los países en desarrollo, especialmente ia utilización efectiva en forma líquida (LNG) de gas asociado al petróleo, requiere de compromisos de cooperación técnica a largo plazo en lo referente a inversiones, recursos humanos y transferencia de tecnología. Este artículo intenta analizar los factores básicos pertinentes a dicha tarea. 相似文献
147.
This paper describes the help given by the social services department of a shipping company to bereaved families following a shipping disaster. In the absence of clear, factual and prompt information from an authoritative source, there is a tendency for bereaved individuals to deny their loss and thereby delay the process of mourning and eventual recovery. Appropriate intervention and support can help to overcome this tendency as was seen in the Madasa case. 相似文献
148.
Results of a recent intercomparison on the determination of trace elements in simulated air filter samples are reported. A large scatter of results is obtained for some elements and systematic differences between laboratories are observed. The performance of different methods, in particular neutron activation analysis and atomic absorption spectrophotometry, used by the various laboratories is discussed (air filter analysis; intercomparison; trace elements; control charts). 相似文献
149.
150.
J A Heidman 《Journal - Water Pollution Control Federation》1975,47(6):1493-1498