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   18730篇
  免费   1766篇
  国内免费   20篇
  2022年   106篇
  2021年   253篇
  2020年   138篇
  2019年   183篇
  2018年   246篇
  2017年   198篇
  2016年   369篇
  2015年   585篇
  2014年   673篇
  2013年   906篇
  2012年   1105篇
  2011年   1150篇
  2010年   736篇
  2009年   725篇
  2008年   999篇
  2007年   1004篇
  2006年   976篇
  2005年   963篇
  2004年   992篇
  2003年   981篇
  2002年   1011篇
  2001年   315篇
  2000年   222篇
  1999年   263篇
  1998年   273篇
  1997年   221篇
  1996年   180篇
  1995年   171篇
  1994年   167篇
  1993年   207篇
  1992年   187篇
  1991年   198篇
  1990年   194篇
  1989年   147篇
  1988年   153篇
  1987年   182篇
  1986年   141篇
  1985年   193篇
  1984年   172篇
  1983年   180篇
  1982年   185篇
  1981年   186篇
  1980年   148篇
  1979年   128篇
  1978年   141篇
  1977年   135篇
  1976年   121篇
  1975年   89篇
  1974年   144篇
  1973年   106篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Variation is a ubiquitous feature of speech. Listeners must take into account context-induced variation to recover the interlocutor''s intended message. When listeners fail to normalize for context-induced variation properly, deviant percepts become seeds for new perceptual and production norms. In question is how deviant percepts accumulate in a systematic fashion to give rise to sound change (i.e., new pronunciation norms) within a given speech community. The present study investigated subjects'' classification of /s/ and // before /a/ or /u/ spoken by a male or a female voice. Building on modern cognitive theories of autism-spectrum condition, which see variation in autism-spectrum condition in terms of individual differences in cognitive processing style, we established a significant correlation between individuals'' normalization for phonetic context (i.e., whether the following vowel is /a/ or /u/) and talker voice variation (i.e., whether the talker is male or female) in speech and their “autistic” traits, as measured by the Autism Spectrum Quotient (AQ). In particular, our mixed-effect logistic regression models show that women with low AQ (i.e., the least “autistic”) do not normalize for phonetic coarticulation as much as men and high AQ women. This study provides first direct evidence that variability in human''s ability to compensate for context-induced variations in speech perceptually is governed by the individual''s sex and cognitive processing style. These findings lend support to the hypothesis that the systematic infusion of new linguistic variants (i.e., the deviant percepts) originate from a sub-segment of the speech community that consistently under-compensates for contextual variation in speech.  相似文献   
43.
The particulate enzyme fraction from pig aorta was treated with Triton X-100 or Nonidet P-40 to yield a soluble enzyme preparation. This solubilized enzyme catalyzed the transfer of mannose from GDP-[14C]mannose, but not from [14C]mannosyl-phosphoryl-polyprenol, to G1cNAc-G1cNAc-pyrophosphoryl-polyprenol to form the trisaccharide-lipid, Man-β-GlcNAc-GlcNAc-pyrophosphoryl-polyprenol. The trisaccharide-lipid formed in these reactions was isolated by solvent fractionation and was subjected to mild acid hydrolysis to release the [14C]trisaccharide. Essentially all of the radioactivity was released from this trisaccharide as mannose upon treatment with β-mannosidase while α-mannosidase had no effect.  相似文献   
44.
A light-weight nonmagnetic, nonconductive instrument has been devised for use with magnetic resonance imaging, computerized tomography, and digital subtraction imaging for work in the field of epilepsy, brain tumors and vascular lesions. The apparatus' main characteristic is its ability to use optionally either the lateral orthogonal or the spherical-radial approach.  相似文献   
45.
46.
47.
48.
49.
50.
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