全文获取类型
收费全文 | 29543篇 |
免费 | 325篇 |
国内免费 | 222篇 |
专业分类
安全科学 | 838篇 |
废物处理 | 1070篇 |
环保管理 | 4037篇 |
综合类 | 4669篇 |
基础理论 | 8553篇 |
环境理论 | 21篇 |
污染及防治 | 7718篇 |
评价与监测 | 1749篇 |
社会与环境 | 1244篇 |
灾害及防治 | 191篇 |
出版年
2022年 | 180篇 |
2021年 | 179篇 |
2019年 | 215篇 |
2018年 | 389篇 |
2017年 | 381篇 |
2016年 | 555篇 |
2015年 | 494篇 |
2014年 | 682篇 |
2013年 | 2139篇 |
2012年 | 846篇 |
2011年 | 1256篇 |
2010年 | 1031篇 |
2009年 | 1034篇 |
2008年 | 1253篇 |
2007年 | 1333篇 |
2006年 | 1187篇 |
2005年 | 1004篇 |
2004年 | 1004篇 |
2003年 | 941篇 |
2002年 | 938篇 |
2001年 | 1240篇 |
2000年 | 862篇 |
1999年 | 550篇 |
1998年 | 427篇 |
1997年 | 435篇 |
1996年 | 443篇 |
1995年 | 483篇 |
1994年 | 440篇 |
1993年 | 397篇 |
1992年 | 414篇 |
1991年 | 373篇 |
1990年 | 376篇 |
1989年 | 411篇 |
1988年 | 347篇 |
1987年 | 300篇 |
1986年 | 276篇 |
1985年 | 305篇 |
1984年 | 286篇 |
1983年 | 322篇 |
1982年 | 322篇 |
1981年 | 271篇 |
1980年 | 243篇 |
1979年 | 269篇 |
1978年 | 229篇 |
1977年 | 195篇 |
1976年 | 200篇 |
1975年 | 192篇 |
1974年 | 172篇 |
1973年 | 171篇 |
1972年 | 198篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
J. Morgan Grove Dexter H. Locke Jarlath P. M. O’Neil-Dunne 《Environmental management》2014,54(3):402-419
Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use diverse data sources including the City’s property database, time-series demographic and socio-economic data from the US Census, and land cover data from the University of Vermont’s Spatial Analysis Lab (SAL). These data are analyzed using a multi-model inferential, spatial econometrics approach. We also examine the distribution of vegetation within distinct market categories using Claritas’ Potential Rating Index for Zipcode Markets (PRIZM?) database. These categories can be disaggregated, corresponding to the four social theories. We compare the econometric and categorical results for validation. Models associated with ecology of prestige theory are more effective for predicting the distribution of vegetation. This suggests that private, residential patterns of vegetation, reflecting the consumption of environmentally relevant goods and services, are associated with different lifestyles and lifestages. Further, our spatial and temporal analyses suggest that there are significant spatial and temporal dependencies that have theoretical and methodological implications for understanding urban ecological systems. These findings may have policy implications. Decision makers may need to consider how to most effectively reach different social groups in terms of messages and messengers in order to advance land management practices and achieve urban sustainability. 相似文献
992.
993.
Nathan J. Waltham Michael Barry Tony McAlister Tony Weber Dominic Groth 《Environmental management》2014,54(4):840-851
The Gold Coast City is the tourist center of Australia and has undergone rapid and massive urban expansion over the past few decades. The Broadwater estuary, in the heart of the City, not only offers an array of ecosystems services for many important aquatic wildlife species, but also supports the livelihood and lifestyles of residents. Not surprisingly, there have been signs of imbalance between these two major services. This study combined a waterway hydraulic and pollutant transport model to simulate diffuse nutrient and sediment loads under past and future proposed land-use changes. A series of catchment restoration initiatives were modeled in an attempt to define optimal catchment scale restoration efforts necessary to protect and enhance the City’s waterways. The modeling revealed that for future proposed development, a business as usual approach to catchment management will not reduce nutrient and sediment loading sufficiently to protect the community values. Considerable restoration of upper catchment tributaries is imperative, combined with treatment of stormwater flow from intensively developed sub-catchment areas. Collectively, initiatives undertaken by regulatory authorities to date have successfully reduced nutrient and sediment loading reaching adjoining waterways, although these programs have been ad hoc without strategic systematic planning and vision. Future conservation requires integration of multidisciplinary science and proactive management driven by the high ecological, economical, and community values placed on the City’s waterways. Long-term catchment restoration and conservation planning requires an extensive budget (including political and societal support) to handle ongoing maintenance issues associated with scale of restoration determined here. 相似文献
994.
995.
996.
997.
998.
999.
1000.