全文获取类型
收费全文 | 2100篇 |
免费 | 92篇 |
专业分类
2192篇 |
出版年
2023年 | 12篇 |
2021年 | 8篇 |
2020年 | 34篇 |
2019年 | 56篇 |
2018年 | 87篇 |
2017年 | 102篇 |
2016年 | 87篇 |
2015年 | 73篇 |
2014年 | 60篇 |
2013年 | 554篇 |
2012年 | 63篇 |
2011年 | 74篇 |
2010年 | 60篇 |
2009年 | 57篇 |
2008年 | 58篇 |
2007年 | 52篇 |
2006年 | 49篇 |
2005年 | 39篇 |
2004年 | 38篇 |
2003年 | 35篇 |
2002年 | 43篇 |
2001年 | 41篇 |
2000年 | 36篇 |
1999年 | 26篇 |
1998年 | 29篇 |
1997年 | 29篇 |
1996年 | 22篇 |
1995年 | 20篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 15篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 21篇 |
1983年 | 21篇 |
1982年 | 21篇 |
1981年 | 13篇 |
1980年 | 18篇 |
1979年 | 17篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1976年 | 14篇 |
1975年 | 15篇 |
1974年 | 8篇 |
1971年 | 8篇 |
排序方式: 共有2192条查询结果,搜索用时 0 毫秒
11.
12.
13.
14.
15.
16.
This article draws on examples of inventive plastic reuse from India and personal anecdotes of elders as an anthropological reflection on possible plastic futures. It sketches the large-scale governmental reforms in the domain of municipal solid waste management, or MSWM (which, by legal definition in India, includes plastic waste). In this regard, it draws out some of the problematic socio-political and environmental implications of Prime Minister Narendra Modi's ‘Clean India’ campaign, whose technocratic policy orientations towards standardized centralized MSWM echo his cultural nationalist agenda. These reforms contrast with home-based re-engineering methods and the redeploying of plastic discards (thereby making them notuner moton (‘like new again’), and their localized circulation through relatively local but uneven reputational and economic networks. Clean India sequesters and processes vast quantities of plastics through the wide-ranging adoption of a waste-to-energy techno-fix (in which plastics are incinerated). In contrast, the authors illustrate routine practices and relations whereby people reuse, repurpose and recycle plastics. While Clean India can detract from and disrupt these mundane practices and everyday relations, these are suggestive of alternative plastic futures – both socio-material and environmental. 相似文献
17.
OPTIMALITY OF RECYCLING AND THE LOCATION OF A RECYCLING CENTER 总被引:1,自引:0,他引:1
ABSTRACT. Consider a community investigating the integration of recycling into its waste management program. Even if (1) the county's citizens do not gain utility from recycling, (2) landfill space is plentiful, and (3) the market price for recyclables is zero, recycling can still be optimal for a local government. By determining the relationship between the amount of recycling and the location of a recycling center, conditions are identified under which recycling will reduce total waste management costs enough that municipal recycling will be optimal. In addition, it is shown that the likelihood of municipal recycling increases with the size of the city. 相似文献
18.
The measurement and interpretation of spatial economic structure have presented many problems for analysts. The notion of a spatial multiplier has received even less formal attention; part of the motivation for this paper is the examination of the degree to which sectoral decomposition analysis might prove useful in illuminating the paths of interaction across space that are associated with changes in exogenous activity levels. In this paper, we present three perspectives that examine spatial structure in the context of an aggregated interregional social accounting matrix for Bangladesh. These perspectives examine structure at the micro-, meso-, and macrolevels and are interpreted with the assistance of several alternative methods, including structural path analysis, the field of influence, the superposition principle, multiregional feedback loop analysis, and the Matrioshka Principle; the results are interpreted analytically and cartographically. Some attention is also devoted to the formulation of a general approach to spatial multipliers. It is shown that the structure of flows and the structure of influence reveal patterns that, taken together, provide important insights into an understanding of structure and may prove to form the basis for the eventual formal presentation of the spatial multiplier. 相似文献
19.
This paper examines interprovincial migration in the People's Republic of China (PRC) during 1982–87 when China was going through economic restructuring. Chinese migration patterns bear some resemblances as well as dissimilarities with those generally observed in Western societies. In China, the age-specific migration rate does not vary much until the preretirement stage. Return to places of origin is obviously the most plausible explanation of Chinese migration patterns. In addition, a clear-cut gender gap exists, higher than that imagined in Western societies. Chinese women appear far behind Chinese men in their propensity to migrate, and the determinants of migration are quite different for Chinese women and Chinese men. 相似文献
20.