全文获取类型
收费全文 | 42920篇 |
免费 | 436篇 |
国内免费 | 301篇 |
专业分类
安全科学 | 1199篇 |
废物处理 | 2333篇 |
环保管理 | 6067篇 |
综合类 | 5781篇 |
基础理论 | 11741篇 |
环境理论 | 15篇 |
污染及防治 | 9685篇 |
评价与监测 | 3295篇 |
社会与环境 | 3312篇 |
灾害及防治 | 229篇 |
出版年
2023年 | 174篇 |
2022年 | 302篇 |
2021年 | 363篇 |
2020年 | 240篇 |
2019年 | 293篇 |
2018年 | 1923篇 |
2017年 | 1874篇 |
2016年 | 1972篇 |
2015年 | 732篇 |
2014年 | 991篇 |
2013年 | 2785篇 |
2012年 | 1620篇 |
2011年 | 2804篇 |
2010年 | 1969篇 |
2009年 | 1887篇 |
2008年 | 2450篇 |
2007年 | 2700篇 |
2006年 | 1384篇 |
2005年 | 1281篇 |
2004年 | 1203篇 |
2003年 | 1221篇 |
2002年 | 1209篇 |
2001年 | 1180篇 |
2000年 | 858篇 |
1999年 | 544篇 |
1998年 | 441篇 |
1997年 | 428篇 |
1996年 | 452篇 |
1995年 | 524篇 |
1994年 | 456篇 |
1993年 | 395篇 |
1992年 | 423篇 |
1991年 | 387篇 |
1990年 | 358篇 |
1989年 | 353篇 |
1988年 | 320篇 |
1987年 | 277篇 |
1986年 | 281篇 |
1985年 | 281篇 |
1984年 | 322篇 |
1983年 | 302篇 |
1982年 | 315篇 |
1981年 | 259篇 |
1980年 | 195篇 |
1979年 | 194篇 |
1978年 | 188篇 |
1977年 | 147篇 |
1975年 | 143篇 |
1973年 | 168篇 |
1972年 | 148篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
E. A. Kleshcheva 《Russian Journal of Ecology》2007,38(2):94-100
A method for estimating the current state of plant communities based on the ecological amplitudes of constituent species is proposed. An original program, Fitoindikatsiya, has been developed to compute the indices of disturbance and homogeneity of plant communities from species ecological scale values. The current state of pine forests in the part of Novosibirsk oblast east of the Ob River has been analyzed; slightly, moderately, and severely disturbed zones have been distinguished. 相似文献
112.
113.
Ricardo Braun 《Environment, Development and Sustainability》2007,9(4):387-411
The implementation of sustainable development may seem a simple concept when written on paper. However to carry-out long term
actions put forward by the Agenda 21 (AG21) at the local level represents one of the main challenges as municipal governments
in general do not have the capacity to effectively implement the process.
Regional environmental assessment (REA) has shown to be effective in supporting decision-making not only to correct environmental
problems due to past unsustainable social-economic developments but also help local governments to implement sustainable actions.
However this requires long-term investments of AG21 plans and projects. The allocation of regular and consistent financial
resources is one of the main ingredients for the sustainable development process. But traditional plans and projects financed
by national and/or international funds may not be sustainable in the long-term because they become dependent on external funding.
Research demonstrate that innovative economic instruments such as ecotaxes represent a feasible alternative to sponsor local
sustainability because taxes are collected permanently by the government and could be invested in continuous actions. Ecotaxes
experiences have provided important reference to structure a municipal incentive model (MIM) to sponsor AG21’s environmental
plans and projects on a long-term (permanent) basis.
However sustainable development cannot be solely through economic investments. A comprehensive municipal environmental management
scheme (MEMS) has been established to support the incentive model. The scheme seeks not only to improve local institutional
framework but also incentive continuous participation of local stakeholders at all levels of society. Participatory events
and the provision of incentives (educational and financial) are key to motivate society to protect the environment and support
actively the sustainable development process as emphasised in the RIO-92 Conference. 相似文献
114.
115.
116.
117.
118.
David W. Mehlman 《Conservation biology》1994,8(4):1141-1145
119.
In this article the authors assert that successful long-term pollution prevention will require changes in the culture and business practices of an organization such that the term “pollution prevention” eventually becomes obsolete. They envision firms evolving to a point where actions that today are referred to as pollution prevention will simply be part of standard business practices and thoroughly embedded in the firms' culture. Although pollution prevention projects and programs need to be highly visible at the outset to communicate throughout the organization and to demonstrate the benefits that can be gained, companies should adopt a long-term strategy aimed at making fundamental changes in the way they do business, rather than relying solely on piecemeal projects and special plans or programs. Such evolution of the firm will maximize the chances of meeting the dual challenges of business competitiveness and environmental stewardship. This article presents a vision for integrating environmental performance with business objectives and suggests practical steps to begin moving toward that vision. 相似文献
120.
B. A. Kerrigan 《Marine Biology》1997,127(3):395-402
The effects of food availability, female size, and social interactions on the quality of Pomacentrus amboinensis larvae at hatching were examined using two field-based experiments. In Experiment 1, food availability and female size significantly
influenced size, eye diameter and levels of yolk reserves of larvae at hatching. Small females (47 to 52 mm standard length,
SL) whose diets were not supplemented, produced the longest larvae (3.0 ± 0.01 mm total length, TL) with the least yolk reserves
(50.1 ± 1.04 μm2). Irrespective of female size, those that received additional food produced larvae with the largest yolk-sacs (large females:
87.60 ± 1.53 μm2; small females: 80.14 ± 1.24 μm2). In Experiment 2, interactions with conspecifics had a greater affect on the somatic development of larvae at hatching than
food availability. Increased social interactions resulted in larvae that were ⋍3% longer, with 2% greater head depth, than
larvae from females that spawned in isolation on the experimental reefs. Fed females produced larvae with ⋍20% more yolk than
larvae from females whose diets were not supplemented. All three factors (food availability, female size, and intensity of
social interactions) tested within these experiments vary spatially and temporally among reefs. There is the potential, therefore,
for larvae at the onset of the planktonic stage to vary in quality, level of development, and probability of survival.
Received: 12 August 1996 / Accepted: 26 August 1996 相似文献