首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1199篇
  免费   136篇
  2021年   15篇
  2019年   15篇
  2018年   16篇
  2017年   12篇
  2016年   21篇
  2015年   38篇
  2014年   32篇
  2013年   49篇
  2012年   58篇
  2011年   42篇
  2010年   41篇
  2009年   27篇
  2008年   42篇
  2007年   39篇
  2006年   31篇
  2005年   32篇
  2004年   41篇
  2003年   30篇
  2002年   43篇
  2001年   28篇
  2000年   40篇
  1999年   27篇
  1998年   19篇
  1997年   14篇
  1994年   13篇
  1993年   10篇
  1992年   35篇
  1991年   32篇
  1990年   30篇
  1989年   29篇
  1988年   32篇
  1987年   25篇
  1986年   21篇
  1985年   18篇
  1984年   18篇
  1983年   27篇
  1982年   24篇
  1981年   22篇
  1980年   15篇
  1979年   20篇
  1978年   17篇
  1977年   14篇
  1976年   18篇
  1975年   14篇
  1974年   15篇
  1973年   14篇
  1972年   14篇
  1971年   12篇
  1970年   8篇
  1967年   8篇
排序方式: 共有1335条查询结果,搜索用时 625 毫秒
81.
82.
83.
Cartilage material properties are important for understanding joint function and diseases, but can be challenging to obtain. Three biphasic material properties (aggregate modulus, Poisson's ratio and permeability) can be determined using an analytical or finite element model combined with optimisation to find the material properties values that best reproduce an experimental creep curve. The purpose of this study was to develop an easy-to-use resource to determine biphasic cartilage material properties. A Cartilage Interpolant Response Surface was generated from interpolation of finite element simulations of creep indentation tests. Creep indentation tests were performed on five sites across a tibial plateau. A least-squares residual search of the Cartilage Interpolant Response Surface resulted in a best-fit curve for each experimental condition with corresponding material properties. These sites provided a representative range of aggregate moduli (0.48–1.58 MPa), Poisson's ratio (0.00–0.05) and permeability (1.7 × 10? 15–5.4 × 10? 15 m4/N s) values found in human cartilage. The resource is freely available from https://simtk.org/home/va-squish.  相似文献   
84.
Abstract

A convenient, high-yield synthesis of 1,3,5-tri-O-acetyl-2-deoxy-α. β-D-erythro-pentofuranose from 2-deoxy-D-erythro-pentose is described.  相似文献   
85.
86.
87.
Gerald L. Gold 《Ethnos》2013,78(1-2):60-81
The Zhi Mä Funeral Ceremony of the Na‐Khi of Southwest China. Joseph F. Rock. Studia Instituti Anthropos, Vol. 9. St. Gabriel's Mission Press, Vienna‐Mödling, 1955. 228 pp., 10 pls.

Mythen und Mysterien. Magie und Religian der Tibeter. M. Hermanns. Verlag Balduin Pick, Köln, 1956. 400 pp., 49 figs., 1 map.

Oracles and Demons of Tibet. René de Nebesky‐Wojkowitz. Mouton &; Co., ‘s‐Gravenhage, 1956. 666 pp., 10 pls., 25 figs.

Die Lamaistische Kunst in der Umwelt von Tibet. Siegbert Hummel. Otto Harrassowitz, Leipzig, 1955. 149 pp., 134 figs., 1 map.

El Monte. Igbo Finda, Ewe Orisha, Vititinfinda. Notas sobre la religión, la magía, las supersticiones y el folklore de los negros criollos y del pueblo de Cuba. Lydia Cabrera. Ediciones C. R., Habana 1954. 564 pp., 25 pls.

Die Hieroglyphen der Maya‐Handschriften. Günter Zimmermann. Universität Hamburg, Abhandlungen aus dem Gebiet der Auslandskunde, Band 62, Reihe B: Völkerkunde, Kulturgeschichte und Sprachen, Band 34. Verlag Cram, de Gruyter &; Co., Hamburg, 1956. 174 pp., 8 pls., ca. 2000 text ill.

Das Indianerbuch. Geb. F. A. Brockhaus Verlag. Leipzig 1956. Eva Lips. 443 PP., 32 pls., 11 text ill., 6 maps. Cloth bound DM 10.80.

Das doppelte Geschlecht. Ethnologische Studien zur Bisexualität in Ritus und Mythos. Hermann Baumann. Berlin 1955. 420 pp., 5 maps.

Von Fremden Völkern und Kulturen. Beiträge zur Völkerkunde. Hans Plischke zum 65. Geburtstage gewidmet von seinen Kollegen und Freunden, Schülern und Mitarbeitern. Herausgegeben von W. Lang, W. Nippold und G. Spannaus. Droste‐Verlag, Düsseldorf, 1955. 284 pp., 30 figs., 2 maps.

Die Wiener Schule der VölkerkundeThe Vienna School of Ethnology. Festschrift anlässlich des 25‐jährigen Bestandes des Institutes für Völkerkunde der Universität Wien (1929–1954). Herausgeber J. Haekel, A. Hohenwart‐Gerlachstein und A. Slawik, Wien 1956. VIII+ 568 S., 11 Taf., 21 Textill, und 2 Karten. $ 8.60.

Das Problem des Völkertodes. Eine Studie zur historischen Bevölkerungsbiologie. Ilse Schwidetzky. Ferdinand Enke Verlag, Stuttgart 1954. 165 pp. This and the following review have been held over from former times, when these contributions were apt to prove rather exhaustive. Reviews are now heavily cut down irrespective of the significance of the work presented.  相似文献   
88.
Several antiepileptic drugs exert their activities by inhibiting Na+ currents. Recent studies demonstrated that compounds containing a biaryl-linked motif (Ar-X-Ar′) modulate Na+ currents. We, and others, have reported that compounds with an embedded benzyloxyphenyl unit (ArOCH2Ar′, OCH2 = X) exhibit potent anticonvulsant activities. Here, we show that benzyloxybenzylammonium chlorides (+H3NCH2C6H4OCH2Ar′ Cl?) displayed notable activities in animal seizure models. Electrophysiological studies of 4-(2′-trifluoromethoxybenzyloxy)benzylammonium chloride (9) using embryonic cortical neurons demonstrated that 9 promoted both fast and slow inactivation of Na+ channels. These findings suggest that the potent anticonvulsant activities of the earlier compounds were due, in part, to the benzyloxyphenyl motif and provide support for the use of the biaryl-linked pharmacophore in future drug design efforts.  相似文献   
89.
90.
The study of stem cells in cnidarians has a history spanning hundreds of years, but it has primarily focused on the hydrozoan genus Hydra. While Hydra has a number of self-renewing cell types that act much like stem cells—in particular the interstitial cell line—finding cellular homologues outside of the Hydrozoa has been complicated by the morphological simplicity of stem cells and inconclusive gene expression data. In non-hydrozoan cnidarians, an enigmatic cell type known as the amoebocyte might play a similar role to interstitial cells, but there is little evidence that I-cells and amoebocytes are homologous. Instead, self-renewal and transdifferentiation of epithelial cells was probably more important to ancestral cnidarian development than any undifferentiated cell lineage, and only later in evolution did one or more cell types come under the regulation of a “stem” cell line. Ultimately, this hypothesis and competing ones will need to be tested by expanding genetic and developmental studies on a variety of cnidarian model systems.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号