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   79942篇
  免费   2496篇
  国内免费   36篇
  82474篇
  2020年   759篇
  2019年   946篇
  2018年   4389篇
  2017年   3724篇
  2016年   3375篇
  2015年   1116篇
  2014年   1252篇
  2013年   5703篇
  2012年   2588篇
  2011年   4347篇
  2010年   3644篇
  2009年   2706篇
  2008年   3586篇
  2007年   3901篇
  2006年   1842篇
  2005年   1826篇
  2004年   1797篇
  2003年   1586篇
  2002年   1563篇
  2001年   1934篇
  2000年   1862篇
  1999年   1430篇
  1998年   838篇
  1997年   720篇
  1996年   608篇
  1995年   637篇
  1994年   621篇
  1993年   626篇
  1992年   1111篇
  1991年   1043篇
  1990年   1032篇
  1989年   937篇
  1988年   911篇
  1987年   892篇
  1986年   877篇
  1985年   934篇
  1984年   769篇
  1983年   657篇
  1982年   562篇
  1981年   533篇
  1980年   523篇
  1979年   748篇
  1978年   581篇
  1976年   529篇
  1975年   646篇
  1974年   690篇
  1973年   644篇
  1972年   568篇
  1968年   554篇
  1967年   551篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
The present study based on the indirect Clausen-test using NTA and PHA as antigens contributed to therapy control and possibly prognosis assessment rather than to immunological differential diagnosis.  相似文献   
993.
The somatic and psychosocial development of 80 subjects with manifest affective-phasic psychoses is studied retrospectively and compared with that of an identically sized control group consisting of neuropsychiatrically healthy subjects. Statistically significant differences were found particularly in the answers to questions dealing with social situation and social adaptability. Achievement at school and vocational qualifications were lower among the parents of the patients than among those of the healthy subjects. Characteristic features of the patients' childhood and adolescence were transient depression, often for no apparent cause, and maladaption, and vocational wishes were fulfilled less often than among the controls. The patients experienced greater difficulty in settling in to a new group due to their contact difficulties.  相似文献   
994.
By 48 patients with Wilson's disease the brainstem acoustic evoked potentials were stated. There were 35 pathological findings (73%), 13 were normal (27%). The waves, determined by the middle and upper brainstem (Pons and Mesencephalon) showed most of all pathological changes. Those patients with forms of Wilson's disease called Pseudoskelerose and Pseudoparkinson showed the most pathological findings. But one could watch these findings by about 30% of patients in preclinical stage. This method can possibly be used for early detection of disorders of brainstem functions and in the same way it can be used for control of treatment by patients in preclinical stage.  相似文献   
995.
996.
Mechanographic examinations have hitherto played only a minor role in general clinical neuromuscular functional diagnostics. The purpose of this contribution is, therefore, to present an appropriate recording apparatus (W. Zett , 1969), to report on the values that can be considered normal and to outline the diagnostic value of the method using clinical applications as examples. Special value is attached to simultaneous recording of the EMG and the mechanograph because this method permits differentiated conclusions to be drawn regarding disturbances in muscular activity, the electromechanical coupling and the actual process of contraction. The method is also important for pharmacological investigations and should be used principally in connection with musclepathology for objectifying the effects of medication.  相似文献   
997.
Asymmetric neural control systems in human self-regulation   总被引:15,自引:0,他引:15  
  相似文献   
998.
Prolonged deprivation and future orientation (FO) were studied in 200 Indian and Nepalese students of 14–16 and 18–20 years with verbal measures. In both cultures low deprived subjects were significantly more future-oriented. In the development of FO both age and deprivation were significant with experiential aspect of socialization exerting greater influence than physico-economic deprivation.  相似文献   
999.
Finke and Pinker (1982, 1983) showed subjects an array of dots followed by an arrow in a blank field, and asked them to determine whether the arrow pointed to any of the previously seen dots. Response times were linearly related to the distance between the arrow and the nearest dot, suggesting that subjects spontaneously used an internal scanning or extrapolation process to perform the task. We replicate and extend this finding by varying the retention interval, and by employing a paradigm in which subjects’ eyes are closed and the arrows are described to them using a coordinate scheme. We also show that subjects are unable to predict the form of the data when the task simply is described to them. Results suggest that mental scanning along a straight path can be performed on images reconstructed from memory, and that it does not depend on the ongoing perception of a continuous surface, on physical eye movements, or on demand characteristics.  相似文献   
1000.
Christians are notably underrepresented in science in part due to long-standing public perceptions of science-religion incompatibility and antireligious bias in science. This research explores whether undergraduates at a Christian university perceive and impose anti-Christian cultural stigma in science. Survey results from 126 biology students revealed that though students generally perceived the culture of science to be anti-Christian, they perceived Christians to have equal opportunities for scientific achievement. Results from a quasi-experimental audit study, in which students evaluated one of two profiles for mock prospective Ph.D. applicants (Christian or undisclosed faith) showed that students did not project anti-Christian stereotypes in terms of competence, hireability, or likeability, but showed some evidence of pro-Christian favorability. Together, this study suggests that the affirmational community of a Christian University may alleviate some negative impacts of anti-Christian stereotypes in academic biology, even as students perceive discrimination against Christians in science and atheists as more scientifically competent.  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