全文获取类型
收费全文 | 7528篇 |
免费 | 364篇 |
国内免费 | 171篇 |
专业分类
安全科学 | 600篇 |
废物处理 | 100篇 |
环保管理 | 1958篇 |
综合类 | 3394篇 |
基础理论 | 460篇 |
环境理论 | 21篇 |
污染及防治 | 378篇 |
评价与监测 | 699篇 |
社会与环境 | 366篇 |
灾害及防治 | 87篇 |
出版年
2024年 | 9篇 |
2023年 | 47篇 |
2022年 | 74篇 |
2021年 | 135篇 |
2020年 | 245篇 |
2019年 | 120篇 |
2018年 | 105篇 |
2017年 | 189篇 |
2016年 | 212篇 |
2015年 | 202篇 |
2014年 | 326篇 |
2013年 | 370篇 |
2012年 | 341篇 |
2011年 | 546篇 |
2010年 | 323篇 |
2009年 | 436篇 |
2008年 | 334篇 |
2007年 | 431篇 |
2006年 | 438篇 |
2005年 | 284篇 |
2004年 | 294篇 |
2003年 | 335篇 |
2002年 | 306篇 |
2001年 | 298篇 |
2000年 | 327篇 |
1999年 | 261篇 |
1998年 | 197篇 |
1997年 | 195篇 |
1996年 | 125篇 |
1995年 | 101篇 |
1994年 | 95篇 |
1993年 | 108篇 |
1992年 | 59篇 |
1991年 | 34篇 |
1990年 | 23篇 |
1989年 | 20篇 |
1988年 | 12篇 |
1987年 | 13篇 |
1986年 | 18篇 |
1985年 | 14篇 |
1984年 | 14篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1978年 | 12篇 |
1977年 | 8篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有8063条查询结果,搜索用时 865 毫秒
751.
ABSTRACT: Local governments often face environmental problems that cross political boundaries. The onus for solution usually falls on the moat severely affected jurisdiction, others do nothing until impacted. Resolution of these problems requires cooperation across political boundaries which means that local governments must be persuaded first that there is a problem, and second that action is required to solve it. This paper presents a method to supply low cost, credible information that can be used to achieve consensus on problem solution. A case study of a lake water quality management problem is described. Formative evaluation techniques was adapted to provide a minimum of evidence which was then used to persuade less impacted local jurisdictions to cooperate in the problem solution. 相似文献
752.
This article addresses the development of an agricultural productivity equation for predicting new soil (neo-sol) plant growth potential in Clay County, Minnesota, USA. Soil factors examined in the study include percent organic matter, percent slope, percent rock fragments, hydraulic conductivity, electrical conductivity, pH, topographic position, available water-holding capacity, bulk density, and percent clay. Squared terms and two-factor interaction terms were also examined as possible regressors. A best equation was selected that had a multiple coefficient of determination of 0.7399 and has five significant regressors and intercept withP.0001. The regressors are hydraulic conductivity, percent slope squared, bulk density times percent rock fragments, electrical conductivity times percent rock fragments, and electrical conductivity times percent organic matter. The regressors predict soil suitability for a general crop model. The crops included in the model are wheat, oats, barley, soybeans, sugar beets, sunflowers, and grasses/legumes. 相似文献
753.
Joseph M. Petulla 《Environmental management》1989,13(3):273-278
Since the term environmental ethics began to be used a generation ago, it has covered many different kinds of environmental notions, problems, ethical systems, and forms of behavior. A variety of cases are presented and examined under two terms,environmental ethics andecological morality, in an effort to illustrate different kinds of ethical objectives. In order to understand the connections between various strands of environmental ethics, personal and social values and subcultural norms of environmental ethics are examined under Christopher Stone's concept of moral pluralism. G. J. Warnock's notion of the general object of morality is proposed to integrate the variegated purposes of environmental ethics. 相似文献
754.
755.
江西省是我国南方山地森林资源丰富的省份之一。本文详细分析了江西山地森林资源的现状和存在的问题,并就山地森林的保护和合理开发利用提出了6项综合治理措施。 相似文献
756.
Environmental degradation, competition for resources, increasing food demands, and the integration of agriculture into the
international economy threaten the sustainability of many food production systems. Despite these concerns, the concept of
sustainable food production systems remains unclear, and recent attempts to appraise sustainability have been hampered by
conceptual inconsistencies and the absence of workable definitions. Six perspectives are shown to underpin the concept. Environmental
accounting identifies biophysical limits for agriculture. Sustained yield refers to output levels that can be maintained continuously.
Carrying capacity defines maximum population levels that can be supported in perpetuity. Production unit viability refers
to the capacity of primary producers to remain in agriculture. Product supply and security focuses on the adequacy of food
supplies. Equity is concerned with the spatial and temporal distribution of products dervied from resource use. Many studies
into sustainable agriculture cover more than one of these perspectives, indicating the concept is complex and embraces issues
relating to the biophysical, social, and economic environments. Clarification of the concept would facilitate the development
of frameworks and analytical systems for appraising the sustainability of food production systems.
LRRC Contribution No. 90–46. 相似文献
757.
One of the objectives of US environmental regulations was to reduce industrial air pollution emissions, especially from the
electric utility industry, the major industrial air polluter. In this study, a comparative analysis of air pollution emissions
from fossil-fuel-burning electric utility plants is conducted. The analysis focuses on a 12-yr period from 1975 to 1987 for
three air pollutants: particulates, surfur dioxide, and nitrogen oxides.
The results indicate that particulate emissions have been significantly reduced but that sulfur dioxide and nitrogen oxides
are still major problems for a number of plants. Furthermore, the disparity in the performance by plants indicates that by
using current technology, the industry as a whole could greatly reduce these emissions. These results have policy implication
for future environmental legislation. 相似文献
758.
作者在对中国我人民解放军第47医院病建项目所产生的大气环境影响进行了医学秤价和影响,并在预测的基础上,建立了完整的环境医学影响廉政价方法,由于该评价方法完全尊循了国内现行大气环境影响评价的基本要求和程序,因此,它在今后的环境影响医学评价中净有广泛的应用。 相似文献
759.
我国部分油田原油生产出砂严重,经常造成集输处理系统的严重磨损和堵塞,储油罐严重积砂,不能实现密闭。储油罐清砂完全靠人工完成,劳动强度大,而且造成环境污染。在海上平台,若采出砂含油量不达标排入海洋,则会给海洋带来严重的污染,因此,采出砂处理是急待解决的问题。文章根据国内外采出砂处理技术调研,介绍了水力旋流器除砂技术原理及工艺和在国外应用实例以及该技术在我国油田的开发应用情况。 相似文献
760.
含油污泥的处理与利用 总被引:12,自引:1,他引:12
石油开采和加工过程中产生的含油污泥,带有有害物质和较高的热值,既需处理又可综合利用,这是一个复杂而又重要的课题。当前,我国含油污泥处理与利用和国外先进水平有较大差距,处理装置技术落后,不配套,多数污泥未进行无害化处理,造成了环境污染和能源资源的浪费。在收集了大量资料的基础上,列举了含油污泥的性质及危害。“九五”期间应积极开展先进工艺设备的引进推广工作,特别在含油污泥的脱水干燥、污油回收和绿化利用上,可推广江汉、中原油田的先进工艺设备,使含油污泥达到无害化乃至变废为宝。 相似文献