全文获取类型
收费全文 | 4340篇 |
免费 | 224篇 |
出版年
2023年 | 28篇 |
2020年 | 79篇 |
2019年 | 88篇 |
2018年 | 144篇 |
2017年 | 172篇 |
2016年 | 183篇 |
2015年 | 133篇 |
2014年 | 126篇 |
2013年 | 1121篇 |
2012年 | 120篇 |
2011年 | 157篇 |
2010年 | 133篇 |
2009年 | 129篇 |
2008年 | 113篇 |
2007年 | 107篇 |
2006年 | 97篇 |
2005年 | 57篇 |
2004年 | 65篇 |
2003年 | 52篇 |
2002年 | 56篇 |
2001年 | 62篇 |
2000年 | 66篇 |
1999年 | 53篇 |
1998年 | 48篇 |
1997年 | 48篇 |
1996年 | 33篇 |
1995年 | 41篇 |
1994年 | 36篇 |
1993年 | 42篇 |
1992年 | 33篇 |
1991年 | 41篇 |
1990年 | 31篇 |
1989年 | 38篇 |
1988年 | 23篇 |
1987年 | 39篇 |
1986年 | 30篇 |
1985年 | 47篇 |
1984年 | 48篇 |
1983年 | 39篇 |
1982年 | 35篇 |
1981年 | 35篇 |
1980年 | 42篇 |
1979年 | 37篇 |
1978年 | 39篇 |
1977年 | 41篇 |
1976年 | 50篇 |
1975年 | 32篇 |
1974年 | 30篇 |
1973年 | 26篇 |
1972年 | 21篇 |
排序方式: 共有4564条查询结果,搜索用时 15 毫秒
991.
Zihni L 《Journal of the history of the neurosciences》1996,5(2):136-142
Albert Wilmarth was an influential physician in nineteenth century America. His works in asylum management, eugenics and neuropathology were intimately interrelated, and his conception of people with Down's syndrome and how they should be treated were largely a product of these relationships. While many of his activities may be perceived in a negative way today, he should be credited with having discovered vasculitis in the brains of people with Down's syndrome during his pathological studies, a condition which is now perceived as autoimmune. 相似文献
992.
We present results of particle size and radioactivity analyses of sediment samples collected from five sites with different burial environments. The uranium, thorium and potassium concentrations in the five sample sets are shown to vary with particle size. The potential effects of the observed size-dependent variations on electron spin resonance (ESR) dating of tooth enamel are assessed using two hypothetical models. Our results show that any bias to relatively fine fractions could result in a significant overestimation of the total environmental dose rate, leading to an underestimation of the calculated ESR age. 相似文献
993.
Eighty-six Roman amphora sherds from the Plemmirio B shipwreck, off Sicily, have been analysed by neutron activation analysis. A large group representative of the amphora cargo, mainly of forms Africana 1 and Africana 2A (from the area of modern Tunisia), was subsequently defined. No differences between Africana 1 and Africana 2A samples were observed, thus implying a similar origin for both forms. The provenance of this cargo group was then investigated by comparison with a Roman amphora kiln data base. After elimination of the more mobile elements it was shown that the cargo amphorae were more likely to have been manufactured at kilns around Sullecthum rather than Leptis Minor. The analytical conclusions are thoroughly consistent with the known archaeological information. 相似文献
994.
The importance of travel-time constraints in spatial choice is widely recognized in the literature of geography and related disciplines, but little work has been done toward developing operational models of spatial choice wherein these constraints and their effects are made explicit. The purpose of the paper is to test the accuracy of predictions produced by a destination choice model that does not take explicit account of travel constraints under the assumption that observed choices are made from choice sets delineated by a constraint of maximum travel time. Observed choices are generated by simulation from a new random utility model consistent with the constrained nature of individual choice sets. Results show that the characteristics of constraints are a decisive factor in the accuracy of the unconstrained choice model. Choice probabilities of the constrained reality are predicted with a reasonably good accuracy in some instances, but predictions are less impressive, and even poor, in many others. 相似文献
995.
996.
Rachel L. Stocking 《Early Medieval Europe》1997,6(2):169-188
In Spain around 624, Bishop Martianus was deposed by a church council led by Bishop Isidore of Seville. The fact that Martianus had been framed came to light at another council in 633, which then issued canons meant to prevent future abuses, and to institutionalize provincial councils as centrally-controlled tribunals for local dispute settlements. These events illuminate the problems involved in the Visigothic church's programme for kingdom-wide religious uniformity. 相似文献
997.
998.
999.
1000.
Douglas L. Oliver Adrian C. Mayer H. D. Black 《Australian Journal of International Affairs》1954,8(1):57-64
“THE SOUTH SEAS IN TRANSITION” by W. E. H. Stanner. Issued under the auspices of the Australian Institute of International Affairs and the International Secretariat, Institute of Pacific Affairs and published by the Australasian Publishing Company. 1953. Pp. viii and 448. Three maps. Australian Published price, 50/‐ net.
SOCIAL ANTHROPOLOGY EN MELANESIA: A REVIEW OF RESEARCH, by A. P. Elkin. Published under the auspices of the South Pacific Commission. Oxford University Press, London, Melbourne, New York, 1953. Pp. xiii, 166 Maps. Price 27/6.
“THE AUSTRALIAN WAY OF LIFE.” Edited by George Caiger, under the auspices of the Australian Institute of International Affairs. Pp. xvi and 158. Published by William Heinemann Ltd., 1953. Australian price, 15/6. 相似文献