全文获取类型
收费全文 | 71篇 |
免费 | 0篇 |
专业分类
废物处理 | 10篇 |
环保管理 | 7篇 |
综合类 | 33篇 |
基础理论 | 3篇 |
污染及防治 | 17篇 |
社会与环境 | 1篇 |
出版年
2018年 | 2篇 |
2017年 | 4篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2003年 | 2篇 |
2001年 | 3篇 |
1970年 | 1篇 |
1965年 | 4篇 |
1964年 | 4篇 |
1963年 | 4篇 |
1962年 | 5篇 |
1961年 | 2篇 |
1960年 | 3篇 |
1959年 | 1篇 |
1950年 | 1篇 |
1939年 | 1篇 |
1938年 | 1篇 |
1934年 | 1篇 |
排序方式: 共有71条查询结果,搜索用时 0 毫秒
41.
42.
43.
44.
45.
46.
The effect of heating technologies on CO(2) and energy efficiency of Dutch greenhouse firms 总被引:1,自引:0,他引:1
This paper uses Data Envelopment Analysis to compute measures of the efficiency (relative to a frontier) in terms of the use of all inputs as well as for single inputs like CO(2) and energy for a sample of greenhouse firms in the Netherlands over the period 1991-1995. These efficiency measures are generated for different firms specialised in production of vegetables, flowers, and potplants and with different heating technologies. The empirical results indicate that firms use energy quite efficiently and are less efficient in terms of CO(2) emissions. Firms using conventional heating are overall less efficiently using energy and CO(2) than firms using more advanced heating technologies. Most differences in efficiency between firm types and firms using different heating technologies are statistically significant. Scale adjustments can provide an important contribution to further efficiency improvements. 相似文献
47.
48.
49.
50.
Pytrik Reidsma Alfons Oude Lansink Frank Ewert 《Mitigation and Adaptation Strategies for Global Change》2009,14(1):35-59
In order to assess agricultural adaptation to climate impacts, new methodologies are needed. The translog distance function
allows assessing interactions between different factors, and hence the influence of management on climate impacts. The Farm
Accountancy Data Network provides extensive data on farm characteristics of farms throughout the EU15 (i.e. the 15 member
states of the European Union before the extension in 2004). These data on farm inputs and outputs from 1990−2003 are coupled
with climate data. As climate change is not the only change affecting European agriculture, we also include effects of subsidies
and other changes on inputs and outputs of farms throughout Europe. We distinguish several regions and empirically assess
(1) climate impacts on farm inputs and outputs in different regions and (2) interactions between inputs and other factors
that contribute to the adaptation to these impacts. Changes in production can partly be related to climatic variability and
change, but also subsidies and other developments (e.g. technology, markets) are important. Results show that impacts differ
per region, and that ‘actual impacts’ cannot be explicitly separated into ‘potential impacts’ and ‘adaptive capacity’ as often
proposed for vulnerability assessment. Farmers adapt their practices to prevailing conditions and continuously adapt to changing
conditions. Therefore, ‘potential impacts’ will not be observed in practice, leaving it as a mainly theoretical concept. Factors
that contribute to the adaptation also differ per region. In some regions more fertilizers or more irrigation can mitigate
impacts, while in other regions this amplifies impacts. To project impacts of future climate change on agriculture, current
farm management strategies and their influence on current production should be considered. This clearly asks for improved
integration of biophysical and economic models. 相似文献