全文获取类型
收费全文 | 1818篇 |
免费 | 68篇 |
专业分类
1886篇 |
出版年
2021年 | 9篇 |
2020年 | 16篇 |
2019年 | 27篇 |
2018年 | 44篇 |
2017年 | 41篇 |
2016年 | 61篇 |
2015年 | 38篇 |
2014年 | 38篇 |
2013年 | 546篇 |
2012年 | 67篇 |
2011年 | 71篇 |
2010年 | 58篇 |
2009年 | 62篇 |
2008年 | 47篇 |
2007年 | 57篇 |
2006年 | 52篇 |
2005年 | 25篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 16篇 |
2001年 | 18篇 |
2000年 | 16篇 |
1999年 | 26篇 |
1998年 | 12篇 |
1997年 | 14篇 |
1996年 | 17篇 |
1995年 | 15篇 |
1994年 | 11篇 |
1993年 | 19篇 |
1992年 | 15篇 |
1991年 | 23篇 |
1989年 | 9篇 |
1988年 | 14篇 |
1987年 | 18篇 |
1986年 | 23篇 |
1985年 | 18篇 |
1984年 | 16篇 |
1983年 | 19篇 |
1982年 | 23篇 |
1981年 | 20篇 |
1980年 | 14篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 13篇 |
1976年 | 16篇 |
1975年 | 15篇 |
1973年 | 11篇 |
1970年 | 9篇 |
1969年 | 11篇 |
1967年 | 15篇 |
排序方式: 共有1886条查询结果,搜索用时 15 毫秒
71.
THE NATIVE RACES OF SOUTH AFRICA : A History of the Intrusion of the Hottentots and Bantu into the Hunting Grounds of the Bushmen. By G. W. STOW, F.G.S. Edited by G. M. THEAL. London: Swan Sonnenschein, 1905. Pp. xvi + 618, with as Plates and a Map. Price 21s. Reviewed by N. W. Thomas. ORIGINES ISLANDICAE, edited and translated by GUDBRAND VIGFUSSON and F. YORE POWELL. Oxford (Clarendon Press), 1905. Reviewed by L. Winifred Faraday. ENGLISH MEDICINE IN THE ANGLO-SAXON TIMES. By JOSEPH FRANK PAYNE. Oxford, at the Clarendon Press, 1904. Reviewed by Bertram C. A. Windle. JUL : ALLESÆLESTIDEN ; HEDENSK, KRISTEN JULEFEST. Vol. I. By H. F. Feilberg. Copenhagen : 1904. Reviewed by W. A. Craigie. JOURNAL OF AMERICAN FOLKLORE, Vol. XVII., Oct.–Dec, 1904. Reviewed by N. W. Thomas. 相似文献
72.
73.
Sarah K. Brown Christyann M. Darwent Benjamin N. Sacks 《Journal of archaeological science》2013,40(2):1279-1288
The domestic dog fulfills many functions for their human companions, such as hauling, guarding, and protection. Consequently, humans have taken dogs to nearly every corner of the globe. Recent translocations of Western dogs stemming from the Victorian era dog fancy have erased some of the ancient genetic signatures of these earlier migrations. Here we used DNA of ancient and modern dogs from the North American Arctic of Alaska and Greenland to assess their genetic continuity in time and space. We successfully sequenced 23 archaeological (ca. AD 1250–1910) and recent (ca. AD 1930–1990) surface-collected Canis bone and tooth samples and compared them to 51 modern Inuit Sled Dogs and to published sequences of modern Alaskan Malamutes (and additional Inuit Sled Dogs) to test for evidence of lineage replacement or genetic continuity through time. Ancient samples from Alaska and Greenland and modern sequences from Greenland all contained a high frequency of haplotype A31, which was previously described only in modern North American Arctic dogs. Thus, A31 was a common thread tying the entire North American Arctic together prior to European colonization and, in the Eastern Arctic, indicates genetic continuity between past and present dogs as well. However, A31 is rare in modern Alaskan dogs, consistent with post-colonization replacement by Eurasian matrilines. 相似文献
74.
Ma Amparo Núñez Felipe Buill Joaquin Regot Andrés de Mesa 《Journal of archaeological science》2013,40(2):1289-1294
3D surveys of archaeological elements and the construction of virtual models enable us to reconstruct historical sites. They provide useful data to select specific building processes.Photogrammetry and Terrestrial Laser Scanning (TLS) are the most common techniques to obtain synthetically heritage models. These techniques provide massive data which can only be managed by replacing them by primitive shapes, thereby obtaining more simple models and the explicit geometry of the element. Statistical and robust methods are used for this substitution, thereby avoiding the common errors due to measuring. Of these methods, the most widely used are the least-median-of-squares (LMedS) and the RANSAC method.Another computation method consists in recursive processes based on evolutive-type algorithms to adjust the model to the data captured.This paper describes two surface computation methodologies to determine the modelling of a column shaft located in temple G of the archaeological park of Selinunte (Sicily). 相似文献
75.
Gilbert J. Price Michael J. Tyler Bernard N. Cooke 《Alcheringa: An Australasian Journal of Paleontology》2013,37(1):171-182
Systematic collecting from fluvial late Pleistocene deposits from the Darling Downs, southeast Queensland, Australia, has led to the recovery of the first fossil frogs from the region, ail from the Myobatrachidae, a family of ground dwelling and burrowing frogs. The most common species recovered, Limnodynastes tasmaniensis, is extant on the Darling Downs. The fossil taxa include species whose extant populations inhabit arid zones(Limnodynastes sp. cf. L. spenceri), montane forests (Kyarranus spp.), and open woodlands (Neobatrachus sudelli), and indicate the existence of a mosaic of habitats during the Pleistocene. The absence of the Hylidae (tree frogs), a family common throughout the Darling Downs today, may be explained by a taphonomic bias that favours non-arboreal forms. Alternatively, hylids may have been rare or absent on the Darling Downs during the Pleistocene. 相似文献
76.
The fossil lycopod Pleuromeia longicaulis (Burges) comb. nov. and its supposed cone Cyclostrobus sydneyensis (Walkom) Helby &; Martin 1965 are common in the Scythian to Anisian Garie and Newport Formations north of Sydney, N.S.W. P. longicaulis probably lived in extensive monodominant stands in the interdistributary bays of the ‘Gosford delta’ system, bordering a large coastal lagoon or lake. C. sydneyensis was borne as a single erect terminal cone. It was shed intact and may have floated some distance before breaking up and releasing its heterospores. Austrostrobus ornatum Morbelli and Petriella 1973 from southern Patagonia is now included as a further species of Cyclostrobus. The Pleuromeiaceae appear to have been facultative coastal halophytes. They probably originated in Eurasia and migrated along early Triassic shorelines, reaching eastern Australia by the mid-Scythian. The coastal habitat of the Pleuromeiaceae and other Triassic lycopods explains the biostratigraphic usefulness of the spores Aratrisporites spp., Nathorstisporites hopliticus Jung 1958, and Banksisporites pinguis (Harris) Dettmann 1961 compared with coexisting fully terrestrial fossil floras. These opportunistic lycopods appear to have expanded in times of recovery from global life crises. 相似文献
77.
78.
80.