全文获取类型
收费全文 | 2740篇 |
免费 | 183篇 |
国内免费 | 64篇 |
专业分类
安全科学 | 166篇 |
废物处理 | 21篇 |
环保管理 | 1165篇 |
综合类 | 820篇 |
基础理论 | 393篇 |
环境理论 | 2篇 |
污染及防治 | 60篇 |
评价与监测 | 82篇 |
社会与环境 | 179篇 |
灾害及防治 | 99篇 |
出版年
2023年 | 19篇 |
2022年 | 39篇 |
2021年 | 54篇 |
2020年 | 67篇 |
2019年 | 55篇 |
2018年 | 61篇 |
2017年 | 91篇 |
2016年 | 111篇 |
2015年 | 100篇 |
2014年 | 95篇 |
2013年 | 142篇 |
2012年 | 97篇 |
2011年 | 159篇 |
2010年 | 104篇 |
2009年 | 134篇 |
2008年 | 128篇 |
2007年 | 139篇 |
2006年 | 130篇 |
2005年 | 114篇 |
2004年 | 94篇 |
2003年 | 105篇 |
2002年 | 72篇 |
2001年 | 75篇 |
2000年 | 82篇 |
1999年 | 91篇 |
1998年 | 54篇 |
1997年 | 53篇 |
1996年 | 46篇 |
1995年 | 45篇 |
1994年 | 31篇 |
1993年 | 23篇 |
1992年 | 30篇 |
1991年 | 22篇 |
1990年 | 14篇 |
1989年 | 14篇 |
1988年 | 16篇 |
1987年 | 22篇 |
1986年 | 24篇 |
1985年 | 27篇 |
1984年 | 24篇 |
1983年 | 15篇 |
1982年 | 18篇 |
1980年 | 15篇 |
1979年 | 17篇 |
1978年 | 20篇 |
1977年 | 14篇 |
1975年 | 10篇 |
1973年 | 16篇 |
1972年 | 14篇 |
1971年 | 16篇 |
排序方式: 共有2987条查询结果,搜索用时 15 毫秒
71.
Hodler TW 《Disasters》1982,6(1):44-49
A survey was conducted of individuals residing directly in the path of the tornado that hit Kalamazoo, Michigan, on 13th May 1980. The residents' tornado preparedness and response were examined in an effort to evaluate the city's emergency warning system. The system was adequate for people on the east side of the city and lacking for west side residents. Other factors pertaining to the storm event and human response were also evaluated. 相似文献
72.
MATLAB在环境评价和规划中的应用 总被引:5,自引:1,他引:5
本文简述了MATLAB软件的由来和发展,介绍了其主要功能及优点。主要通过在环境评价与规划中的应用实例,展示其在环境科学研究中的应用潜力。文中的第一个实例是MATLAB在多项水质参数的综合评价中的应用,文中对不同的多项水质参数评价方法进行了比较;另一个实例是MATLAB应用于城市固体废物管理规划,极大地提高了规划的水平和准确性,提高了工作效率。最后文中对于该软件在环境学科研究中的应用潜力和优势展开了讨论。 相似文献
73.
上海地区湿地生态旅游资源研究 总被引:6,自引:0,他引:6
从国内外湿地研究进展中发现,湿地景观资源及其管理对策研究得到人们越来越广泛的重视。上海市湿地面积广阔,占全市海拔-5m以上总面积9123km^2的65.67%,同时具有景观多样性和生物物种多样性。丰富的湿地资源为上海市提供了广阔的绿地空间,成为宝贵的旅游资源。本文对上海市的湿地景观资源进行了细致的分析,并介绍了其开发和利用现状,在此基础上提出了规划设想和几点建议。 相似文献
74.
Major mining companies have recently embraced the sustainable development paradigm, in seeking to improve their competitiveness and increase shareholder returns. Successful mine closure is one important element of this process. Improved performance in this area is essential if surrounding communities are to see mining companies as responsible corporate and social partners.
In Indonesia, the new approach has coincided with the development of specific mine closure legislation. To facilitate the legislation, a consortium of mining companies joined to form the Industry Mine Closure Steering Committee. This Committee has lobbied the Government, actively negotiating to incorporate sustainable development ideals and practices into the new legislation. The Committee's aim has been to foster continued development of the mining industry, while taking account of variation in environmental, social and community conditions. In describing the process, this article seeks to provide guidance for the development of mine closure legislation in other nations. 相似文献
In Indonesia, the new approach has coincided with the development of specific mine closure legislation. To facilitate the legislation, a consortium of mining companies joined to form the Industry Mine Closure Steering Committee. This Committee has lobbied the Government, actively negotiating to incorporate sustainable development ideals and practices into the new legislation. The Committee's aim has been to foster continued development of the mining industry, while taking account of variation in environmental, social and community conditions. In describing the process, this article seeks to provide guidance for the development of mine closure legislation in other nations. 相似文献
75.
Baxter E. Vieux Fekadu G. Moreda 《Journal of the American Water Resources Association》2003,39(4):757-769
ABSTRACT: A synthetic relationship is developed between nutrient concentrations and discharge rates at two river gauging sites in the Illinois River Basin. Analysis is performed on data collected by the U.S. Geological Survey (USGS) on nutrients in 1990 through 1997 and 1999 and on discharge rates in 1988 through 1997 and 1999. The Illinois River Basin is in western Arkansas and northeastern Oklahoma and is designated as an Oklahoma Scenic River. Consistently high nutrient concentrations in the river and receiving water bodies conflict with recreational water use, leading to intense stakeholder debate on how best to manage water quality. Results show that the majority of annual phosphorus (P) loading is transported by direct runoff, with high concentrations transported by high discharge rates and low concentrations by low discharge rates. A synthetic relationship is derived and used to generate daily phosphorus concentrations, laying the foundation for analysis of annual loading and evaluation of alternative management practices. Total nitrogen (N) concentration does not have as clear a relationship with discharge. Using a simple regression relationship, annual P loadings are estimated as having a root mean squared error (RMSE) of 39.8 t/yr and 31.9 t/yr and mean absolute percentage errors of 19 percent and 28 percent at Watts and Tahlequah, respectively. P is the limiting nutrient over the full range of discharges. Given that the majority of P is derived from Arkansas, management practices that control P would have the most benefit if applied on the Arkansas side of the border. 相似文献
76.
王起全 《中国安全科学学报》2003,13(6):76-79
职业安全健康管理体系 (OSHMS)与ISO90 0 0和ISO14 0 0 0等标准化管理体系一起被称为是后工业化时代的管理方法 ,构成了现代企业管理制度的核心内容之一。笔者首先概述了职业安全健康产生的国际、国内背景以及历史沿革及当今发展概况 ;其次 ,提出了职业安全健康管理体系在市场准入机制、认证结果的客观性和公正性、“三标”一体化等方面应引起关注的一些问题 ;在此基础上预测了其将来的发展方向 相似文献
77.
Sheng‐Feng Kuo Chen‐Wuing Liu Shih‐Kai Chen 《Journal of the American Water Resources Association》2003,39(1):59-73
ABSTRACT: This study presents three optimization techniques for on‐farm irrigation scheduling in irrigation project planning: namely the genetic algorithm, simulated annealing and iterative improvement methods. The three techniques are applied to planning a 394.6 ha irrigation project in the town of Delta, Utah, for optimizing economic profits, simulating water demand, and estimating the crop area percentages with specific water supply and planted area constraints. The comparative optimization results for the 394.6 ha irrigated project from the genetic algorithm, simulated annealing, and iterative improvement methods are as follows: (1) the seasonal maximum net benefits are $113,826, $111,494, and $105,444 per season, respectively; and (2) the seasonal water demands are 3.03*103 m3, 3.0*103 m3, and 2.92*103 m3 per season, respectively. This study also determined the most suitable four parameters of the genetic algorithm method for the Delta irrigated project to be: (1) the number of generations equals 800, (2) population size equals 50, (3) probability of crossover equals 0.6, and (4) probability of mutation equals 0.02. Meanwhile, the most suitable three parameters of simulated annealing method for the Delta irrigated project are: (1) initial temperature equals 1,000, (2) number of moves equal 90, and (3) cooling rate equals 0.95. 相似文献
78.
79.
孙保和 《中国环境管理干部学院学报》2003,13(2):27-29
秦皇岛市区内生态类型多样,各类生态系统功能突出,自然资源丰富,尤其是海、旅游资源优势突出,为区域经济发展提供了良好的基础条件。该文对秦皇岛市生态系统平衡及资源开发利用水平进行了定量分析。 相似文献
80.
Lee H. Macdonald Donald M. Anderson William E. Dietrich 《Environmental management》1997,21(6):851-863
2 /yr, respectively. Geomorphic evidence indicates that plantation agriculture during the 18th and 19th centuries did not cause
severe erosion. Since about 1950 there has been rapid growth in roads and development due to increasing tourism and second-home
development. Our field investigations identified the approximately 50 km of unpaved roads as the primary source of anthropogenic
sediment. Field measurements of the road network in two catchments led to the development of a vector-based GIS model to predict
road surface erosion and sediment delivery. We estimate that road erosion has caused at least a fourfold increase in island-wide
sediment yields and that current sedimentation rates are unprecedented. Paving the dirt roads and implementing standard sediment
control practices can greatly reduce current sediment yields and possible adverse effects on the marine ecosystems surrounding
St. John. 相似文献