全文获取类型
收费全文 | 32023篇 |
免费 | 312篇 |
国内免费 | 265篇 |
专业分类
安全科学 | 821篇 |
废物处理 | 1359篇 |
环保管理 | 3989篇 |
综合类 | 6079篇 |
基础理论 | 8452篇 |
环境理论 | 13篇 |
污染及防治 | 8080篇 |
评价与监测 | 2124篇 |
社会与环境 | 1488篇 |
灾害及防治 | 195篇 |
出版年
2022年 | 230篇 |
2021年 | 220篇 |
2018年 | 408篇 |
2017年 | 419篇 |
2016年 | 652篇 |
2015年 | 493篇 |
2014年 | 784篇 |
2013年 | 2404篇 |
2012年 | 951篇 |
2011年 | 1293篇 |
2010年 | 1054篇 |
2009年 | 1087篇 |
2008年 | 1277篇 |
2007年 | 1319篇 |
2006年 | 1198篇 |
2005年 | 1041篇 |
2004年 | 1015篇 |
2003年 | 996篇 |
2002年 | 933篇 |
2001年 | 1218篇 |
2000年 | 859篇 |
1999年 | 532篇 |
1998年 | 379篇 |
1997年 | 412篇 |
1996年 | 411篇 |
1995年 | 473篇 |
1994年 | 433篇 |
1993年 | 380篇 |
1992年 | 397篇 |
1991年 | 404篇 |
1990年 | 426篇 |
1989年 | 385篇 |
1988年 | 368篇 |
1987年 | 315篇 |
1986年 | 318篇 |
1985年 | 299篇 |
1984年 | 344篇 |
1983年 | 307篇 |
1982年 | 354篇 |
1981年 | 311篇 |
1980年 | 247篇 |
1979年 | 279篇 |
1978年 | 257篇 |
1977年 | 219篇 |
1976年 | 207篇 |
1975年 | 210篇 |
1974年 | 235篇 |
1973年 | 220篇 |
1972年 | 220篇 |
1971年 | 213篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
231.
232.
REED F. NOSS ERICA FLEISHMAN† DOMINICK A. DELLASALA‡ JOHN M. FITZGERALD§ MART R. GROSS MARTIN B. MAIN†† FIONA NAGLE‡‡ STACEY L. O'MALLEY JON ROSALES§§ 《Conservation biology》2009,23(4):825-833
Abstract: The Society for Conservation Biology (SCB) can enhance conservation of biodiversity in North America by increasing its engagement in public policy. Toward this end, the North America Section of SCB is establishing partnerships with other professional organizations in order to speak more powerfully to decision makers and taking other actions—such as increasing interaction with chapters—geared to engage members more substantively in science-policy issues. Additionally, the section is developing a North American Biodiversity Blueprint, which spans the continental United States and Canada and is informed by natural and social science. This blueprint is intended to clarify the policy challenges for protecting continental biodiversity, to foster bilateral collaboration to resolve common problems, and to suggest rational alternative policies and practices that are more likely than current practices to sustain North America's natural heritage. Conservation scientists and practitioners can play a key role by drawing policy makers' attention to ultimate, as well as proximate, causes of biodiversity decline and to the ecological and economic consequences of not addressing these threats. 相似文献
233.
234.
Ronald R. Swaisgood 《Conservation biology》2009,23(5):1338-1340
235.
THOMAS K. RUDEL RUTH DEFRIES GREGORY P. ASNER WILLIAM F. LAURANCE 《Conservation biology》2009,23(6):1396-1405
Abstract: Over the past 50 years, human agents of deforestation have changed in ways that have potentially important implications for conservation efforts. We characterized these changes through a meta‐analysis of case studies of land‐cover change in the tropics. From the 1960s to the 1980s, small‐scale farmers, with state assistance, deforested large areas of tropical forest in Southeast Asia and Latin America. As globalization and urbanization increased during the 1980s, the agents of deforestation changed in two important parts of the tropical biome, the lowland rainforests in Brazil and Indonesia. Well‐capitalized ranchers, farmers, and loggers producing for consumers in distant markets became more prominent in these places and this globalization weakened the historically strong relationship between local population growth and forest cover. At the same time, forests have begun to regrow in some tropical uplands. These changing circumstances, we believe, suggest two new and differing strategies for biodiversity conservation in the tropics, one focused on conserving uplands and the other on promoting environmental stewardship in lowlands and other areas conducive to industrial agriculture. 相似文献
236.
237.
238.
239.
240.