全文获取类型
收费全文 | 610篇 |
免费 | 20篇 |
出版年
2019年 | 11篇 |
2018年 | 18篇 |
2017年 | 15篇 |
2016年 | 19篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 214篇 |
2012年 | 8篇 |
2011年 | 10篇 |
2010年 | 15篇 |
2009年 | 13篇 |
2008年 | 13篇 |
2007年 | 12篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1973年 | 3篇 |
1972年 | 6篇 |
1970年 | 6篇 |
1968年 | 3篇 |
排序方式: 共有630条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
95.
96.
97.
Francesco Vidoli Fabio Quintiliani Giorgio Ivaldi Giorgia Marinuzzi Francesco Porcelli Walter Tortorella 《Journal of regional science》2024,64(2):308-332
Homogeneous national policies can generate heterogeneous effects on the territory. This paper aims to verify the impact of the entry of single Italian municipalities into an inter-municipal association on the unitary costs of the social services supplied to the local communities. Panel cost stochastic frontier model in the presence of endogeneity has been introduced based on two pillars: a counterfactual setting to verify the aggregation effects concerning a set of similar municipalities and the use of a cost efficiency estimation methodology which considers the endogeneity of output with respect to cost. The results of our analysis show that the effects of adopting associated forms of service delivery can be very multifaceted and diversified according to the typology and the degree of implementation of the Municipal Union itself. The analysis sheds light on the effects of municipalities' organisational choices, addressing the consolidation of small municipalities not in binary terms but also—and above all—suggesting that it is the type of union that impacts the possibility of convergence towards greater cost efficiency. 相似文献
98.
99.
Charlotte L. Oskam Chris Jacomb Morten E. Allentoft Richard Walter R. Paul Scofield James Haile Richard N. Holdaway Michael Bunce 《Journal of archaeological science》2011
Using ancient DNA (aDNA) extracted from eggshell of the extinct moa (Aves: Dinornithiformes) we determined the species composition and number of eggs found in a late thirteenth century earth oven feature at Wairau Bar (South Island, New Zealand) – one of New Zealand’s most significant archaeological sites. Mitochondrial and nuclear DNA signatures confirmed this oven feature contained fragments of at least 31 moa eggs, representing three moa genera: Emeus; Euryapteryx; Dinornis. We demonstrate through the genetic identification of 127 moa eggshell fragments that thickness is an unreliable character for species assignment. We also present a protocol for assessing the preservation likelihood of DNA in burnt eggshell. This is useful because eggshell fragments found in archaeological contexts have often been thermally modified, and heat significantly increases DNA fragmentation. Eggshell is widely used in radiocarbon dating and stable isotope research, this study showcases how aDNA can also add to our knowledge of eggshell in both archaeological and palaeoecological contexts. 相似文献
100.
Chuang-Sheng Walter Yang Reginald DesRoches Glenn J. Rix 《Journal of Earthquake Engineering》2013,17(4):579-594
This study develops seismic fragility curves for vertical-pile-supported wharves commonly found in the western United States. Nonlinear time-history analyses of a two-dimensional numerical model under two ground motion suites are performed. The results show that the jumbo container cranes increase by 10.8% in the wharf deck drift. By using the experiment-based limit states, the proposed fragility curves demonstrate that, at a PGA of 0.50 g, the probabilities of exceeding slight, moderate, extensive, and complete limit states are approximately 23.0%, 7.0%, 4.0%, and 3.0%, respectively, while at a PGA of 1.00 g, the exceeding probabilities increase to 44.0%, 19.0%, 14.0%, and 11.0%, respectively. 相似文献