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   12179篇
  免费   1504篇
  国内免费   4篇
  13687篇
  2022年   126篇
  2021年   248篇
  2020年   150篇
  2019年   184篇
  2018年   212篇
  2017年   180篇
  2016年   336篇
  2015年   483篇
  2014年   520篇
  2013年   566篇
  2012年   781篇
  2011年   678篇
  2010年   438篇
  2009年   398篇
  2008年   523篇
  2007年   475篇
  2006年   446篇
  2005年   452篇
  2004年   492篇
  2003年   413篇
  2002年   424篇
  2001年   229篇
  2000年   252篇
  1999年   255篇
  1998年   145篇
  1997年   144篇
  1996年   127篇
  1994年   112篇
  1993年   101篇
  1992年   210篇
  1991年   197篇
  1990年   194篇
  1989年   185篇
  1988年   171篇
  1987年   171篇
  1986年   171篇
  1985年   172篇
  1984年   155篇
  1983年   138篇
  1982年   115篇
  1981年   108篇
  1980年   108篇
  1979年   145篇
  1978年   125篇
  1977年   100篇
  1976年   103篇
  1975年   102篇
  1973年   118篇
  1972年   99篇
  1971年   95篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
UAT, also designated galectin 9, is a multifunctional protein that can function as a urate channel/transporter, a regulator of thymocyte-epithelial cell interactions, a tumor antigen, an eosinophil chemotactic factor, and a mediator of apoptosis. We review the evidence that UAT is a transmembrane protein that transports urate, describe our molecular model for this protein, and discuss the evidence from epitope tag and lipid bilayer studies that support this model of the transporter. The properties of recombinant UAT are compared with those of urate transport into membrane vesicles derived from proximal tubule cells in rat kidney cortex. In addition, we review channel functions predicted by our molecular model that resulted in the novel finding that the urate channel activity is regulated by sugars and adenosine. Finally, the presence and possible functions of at least 4 isoforms of UAT and a closely related gene hUAT2 are discussed. Published in 2004.  相似文献   
12.
13.
14.
Hersh Cohen 《CMAJ》1982,127(10):955-956
  相似文献   
15.
Reconstruction of normal shoulder contour is possible utilizing a latissimus dorsi musculocutaneous flap at the end of a long neurovascular pedicle. The thoracodorsal vessels and their lateral divisions form the basis of the pedicle. The nerve in the pedicle is left intact if maintenance of muscle bulk is desired and sectioned if atrophy is preferred. The amount of muscle taken in conjunction with the skin island is determined by the nature of the defect to be corrected. The twin goals of a single-stage reconstruction and a satisfactory aesthetic result are achieved with this method.  相似文献   
16.
17.
18.
Contradictory models of dependency and development have dominated the discussion of migration between Mexico and the United States. Transnational models of migration resolve these contradictions by defining a series of interdependencies (economy and society, for example). Using data collected in a rural Zapotec community in Oaxaca, Mexico, this article focuses on three areas: the stage-specific development of transnational movement; the domestic cycle, household decision making, and migration/remittance outcomes; and the changing nature of community participation. Rooting the discussion in household decision making captures the important role local social variability and economic dynamism play in understanding transnational processes and advancing migration studies. [ households, migration, transnationalism, dependency and development, Oaxaca, Mexico ]  相似文献   
19.
The experiment was performed using two young male camels which weighed 24 and 36 kg respectively at birth. Each young camel was weighed and abruptly separated from its mother after 30 days of nursing (or at 1 month of age). The weaned calves were fed milk substitutes prepared commercially for lambs by Mabarot Chemical and Veterinary Products (Israel). The weanling camels averaged daily weight gains of 0.400 and 1.0 kg per day respectively during the 30 day initial period when the milk substitutes were used. Following the period when milk substitutes were used, the camels achieved normal growth to arrive at 135 and 145 kg respectively at 6 months of age.  相似文献   
20.
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