全文获取类型
收费全文 | 1074篇 |
免费 | 39篇 |
国内免费 | 82篇 |
专业分类
安全科学 | 158篇 |
废物处理 | 12篇 |
环保管理 | 407篇 |
综合类 | 200篇 |
基础理论 | 184篇 |
环境理论 | 3篇 |
污染及防治 | 74篇 |
评价与监测 | 45篇 |
社会与环境 | 57篇 |
灾害及防治 | 55篇 |
出版年
2023年 | 7篇 |
2022年 | 22篇 |
2021年 | 28篇 |
2020年 | 34篇 |
2019年 | 29篇 |
2018年 | 24篇 |
2017年 | 30篇 |
2016年 | 49篇 |
2015年 | 40篇 |
2014年 | 40篇 |
2013年 | 90篇 |
2012年 | 37篇 |
2011年 | 64篇 |
2010年 | 30篇 |
2009年 | 56篇 |
2008年 | 45篇 |
2007年 | 59篇 |
2006年 | 48篇 |
2005年 | 40篇 |
2004年 | 39篇 |
2003年 | 46篇 |
2002年 | 26篇 |
2001年 | 26篇 |
2000年 | 31篇 |
1999年 | 26篇 |
1998年 | 19篇 |
1997年 | 11篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 15篇 |
1993年 | 17篇 |
1992年 | 10篇 |
1991年 | 14篇 |
1990年 | 4篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1984年 | 4篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 10篇 |
1971年 | 8篇 |
1970年 | 4篇 |
排序方式: 共有1195条查询结果,搜索用时 15 毫秒
601.
Douglas V. Smith 《Journal of the American Water Resources Association》1972,8(6):1225-1234
Recent progress in operations research has refined stochastic programming with recourse sufficiently to significantly increase its potential for use in water resource planning. To demonstrate its strengths and weaknesses this paper considers an irrigation planning problem and illustrates how more and more refined variants of this problem are successively cast into stochastic programming with recourse forms. The result is an outline of the state of the art with method limitations and demands on model formulation clearly indicated. 相似文献
602.
Stan Openshaw 《Journal of Environmental Planning and Management》1986,29(2):66-70
The paper outlines the emerging effects of the Information Technological revolution and examines the likely consequences for planning in Britain. A number of possible scenarios are described as a basis for thinking about the design of a new planning system for the future. 相似文献
603.
Comparison of two fatal occupational injury surveillance systems in the United States 总被引:2,自引:0,他引:2
INTRODUCTION: Using different methods, two national systems compile fatal occupational injury data in the United States: the National Institute for Occupational Safety and Health (NIOSH) National Traumatic Occupational Fatalities (NTOF) surveillance system, and the Bureau of Labor Statistics (BLS) Census of Fatal Occupational Injuries (CFOI). The NTOF uses only death certificates, while CFOI uses multiple sources for case ascertainment. METHODS: Through overall and case-by-case comparisons, this study compares these systems and evaluates counts for the nation and by state for worker and case characteristics. RESULTS: From 1992 through 1994, NTOF reported an average of 84% of the number of traumatic occupational fatalities reported in CFOI. This percentage changed somewhat when a case-by-case comparison was conducted--88% of the NTOF cases were matched directly to the CFOI cases. Although CFOI captured a larger number of fatalities annually, the additional fatalities did not follow a discernable pattern. IMPACT ON INDUSTRY: By understanding the distribution of fatalities, targeted efforts to reduce them will benefit all industries. 相似文献
604.
For over a century, western economic development has depended upon the use of combustible hydrocarbons for its energy needs. The 20th century saw the prolific exploitation of fossil hydrocarbon sources (coal and oil) which are finite and exhaustible. There is a clear need for society to conserve such non-renewable resources. In addition to conservation, a wholesale switch to renewable energy sources should be seen as the first research and development priority. In the interim, moving towards a crop-based fuel economy appears to be a good alternative to provide the necessarily dramatic changes in lifestyle and mindset that would be required of consumers, for a wholesale shift away from hydrocarbon combustion. Before programs and policies designed to address the need for an interim or alternative energy and materials economy are put into place however, it is important to understand the barriers and opportunities put forth by society itself. Conventional frameworks designed to understand this type of change are of limited assistance. This paper argues that institutional thinking is a very useful tool in addressing these types of environmental problems. 相似文献
605.
I. F. Salkin 《Journal of Material Cycles and Waste Management》2003,5(1):0009-0012
The limited scientific information about infectious waste, and the heightened public awareness of this special component
of the waste stream, have contributed to the implementation or strengthening of the regulations in this area. This paper proposes
a general working definition of infectious waste, and describes the systems used to limit its potential occupational and public
health impacts. Although incineration and autoclaving are the most widely used methods of treating infectious waste, the introduction
of more stringent air-quality standards for incinerators, and the inherent limitations to the application of autoclaves, have
created a demand for other methods of processing this segment of the solid and liquid waste streams. These alternative technologies
use one or more of the following methods: (1) heating the waste to a minimum of 90–95°C; (2) exposing the waste to suitable
chemicals; (3) subjecting the waste to heated chemicals; (4) irradiating the infectious waste with ionizing sources. The advantages
and disadvantages of each of these alternative forms of treatment are discussed in this paper.
Received: April 22, 2002 / Accepted: October 14, 2002 相似文献
606.
分析了我国加入WTO后职业安全管理存在的新情况,认真回顾总结了计划经济体制下的职业安全管理经验,探讨了市场经济体制下的职业安全管理方法,以最大限度地防止或减少各类事故的发生。 相似文献
607.
J. Bosch F. Strozzi T. J. Snee J. A. Hare J. M. Zaldívar 《Journal of Loss Prevention in the Process Industries》2004,17(6):389-395
In this work, we have analysed the use of pressure instead of temperature measurements for the early warning detection of runaway initiation. This is possible due to the fact that our runaway criterion, i.e. div>0, does not depend specifically on which state space variable we are using for divergence calculation. A series of runaway experiments, carried out in a 250 l pilot-scale reactor, has been used to compare the results. In accordance with previous analysis, we show that by using temperature, early detection of runaway initiation is achieved. Analogously to temperature, pressure may be also used for runaway detection. By comparing the different types of reactive systems analysed (vapour and gassy), it can be observed that temperature works better, in terms of earlier detection, than pressure but the differences are more pronounced for vapour than for gassy systems. 相似文献
608.
C. J. C. Phillips J. Tind Sorensen 《Journal of Agricultural and Environmental Ethics》1993,6(1):61-73
Cattle production has the potential of being an important component of sustainable agriculture globally. The ability to transform feed not suitable for humans into high-quality food will be of great importance in the long-term for feeding a growing population. Other aspects such as preservation of landscape values and maintenance of rural communities are highly appreciated values, especially in the industrialized part of the world.To exploit the sustainable potential of cattle production systems, problems of pollution (such as ozone destruction, acid rain, and nitrate leaching) and of health and welfare, which are associated with cattle production, are critically reviewed. The possibilities of integrating cattle production with other types of production are evaluated. Cattle can be used for single purposes such as dairy, beef, and draught, but dairy cows can also be used for restricted suckling combining dairy and beef production. In addition a mixture of species makes grazing more efficient, and a combination of cattle and mixed cropping can increase resource efficiency.The possibilities of using organic cattle production systems as prototypes of sustainable cattle production systems are explored. The effects of production constraints which are applied in organic farming systems are studied. The redirection of values and activities in agriculture is a challenge to cattle production research and to traditional research methodologies. 相似文献
609.
Jefferson Fox Rebekah Kanter Sanay Yarnasarn Methi Ekasingh Royce Jones 《Environmental management》1994,18(3):391-399
This research has two interrelated objectives. The first is to determine the extent to which a relationship exists between
farmer characteristics and farming practices in three villages in northern Thailand. The second is to use standard statistical
methods for incorporating spatial variables into the analysis and to assess the effects of these variables on farmer decision
making. The data base includes information on the location and size of villages, roads, streams, and fields; a digital elevation
model with information on elevation, slope, and aspect; and information keyed to individual fields on crops and cropping methods
and the ethnicity, income, and religion of farmers. The map data (517 plots) were entered into a computerized geographic information
systems (GIS). Results suggest several hypotheses about the relationships between land use and owner characteristics. More
significantly, the study concludes that spatial analysis appears to be most useful when the dependent variable is either continuous
or ordinal. The outlook is not quite as optimistic when the dependent variable is a nonordinal categorical variable. Before
spatial analysis can be applied regularly to social science data, better computational tools need to be developed. 相似文献
610.
John L. Hammen Philip J. Gerla 《Journal of the American Water Resources Association》1994,30(5):833-840
ABSTRACT: The 1986 Amendments to the Safe Drinking Water Act mandate a multifaceted approach to wellhead protection. This approach includes: (1) delineating wellhead protection areas; (2) identifying and managing potential contaminants; (3) developing contingency plans in the event of weilfield contamination; (4) siting new wells; and (5) encouraging public participation. These elements encompass technical, administrative, and educational considerations. In functioning both as a research tool and as a decision support system, a geographic information system (GIS) is shown to have proven utility in addressing these issues. This article describes the application of common GIS functionality in facilitating a comprehensive wellhead protection scheme for an agricultural municipality in North Dakota. 相似文献