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   24940篇
  免费   1106篇
  国内免费   16篇
  26062篇
  2020年   323篇
  2019年   375篇
  2018年   508篇
  2017年   537篇
  2016年   574篇
  2015年   433篇
  2014年   503篇
  2013年   2198篇
  2012年   882篇
  2011年   942篇
  2010年   592篇
  2009年   552篇
  2008年   760篇
  2007年   729篇
  2006年   661篇
  2005年   580篇
  2004年   593篇
  2003年   553篇
  2002年   597篇
  2001年   799篇
  2000年   794篇
  1999年   585篇
  1998年   313篇
  1997年   294篇
  1996年   248篇
  1995年   263篇
  1994年   224篇
  1993年   235篇
  1992年   462篇
  1991年   417篇
  1990年   431篇
  1989年   415篇
  1988年   381篇
  1987年   352篇
  1986年   377篇
  1985年   382篇
  1984年   340篇
  1983年   319篇
  1982年   230篇
  1981年   269篇
  1979年   305篇
  1978年   280篇
  1977年   243篇
  1976年   226篇
  1975年   289篇
  1974年   344篇
  1973年   263篇
  1972年   266篇
  1969年   252篇
  1968年   247篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
The authors cite clinical literature attesting to the importance of recognizing the family, rather than the individual, as the proper locus of conceptualizing, diagnosing, and treating mental illnesses. Specifically with regard to severe psychiatric illnesses, in particular schizophrenia, family dysfunction contributes to the emergence of the illness, significantly affects its course, and strongly influences the achievement and maintenance of treatment gains. Currently, a movement is afoot to limit sharply the amount and kind of treatment offered to schizophrenic patients and their families. Rooted in a “medical model” or “biogenic” view of the etiology of schizophrenia, this school of thought prescribes psychoeducation as the family treatment of choice. The present article looks at some misconceptions regarding treatment that prompted a widespread turning away from psychoanalytically oriented family psychotherapy for schizophrenic patients and their families, examines the reductionism (biological and behavioral) inhering in the exclusive use of psychoeducation, and looks at the clinical dangers of such reductionism. Finally, it proposes that family psycho-therapists should not abandon a concern with the inner lives of severely ill patients and their families in the face of spuriously generalized claims made by reductionist researchers.  相似文献   
54.
55.
56.
57.
Force variability in isometric responses   总被引:2,自引:0,他引:2  
In the present study we examined the contribution of different impulse parameters to peak force variability in an isometric task. Five experiments are reported that each held constant a different impulse parameter while allowing the other impulse parameters to vary. The results indicate that change in force level is the parameter that has the greatest effect on peak force variability, although time to peak force and preload also systematically influence response variability. A formula that accommodates the relation between impulse parameters and force variability is proposed. The data suggest that even in isometric tasks, it is the force-time properties of the impulse, rather than discrete parameters such as peak force, that determine the outcome variability.  相似文献   
58.
Short-term memory for Chinese characters and radicals   总被引:1,自引:0,他引:1  
Short-term memory for Chinese radicals and characters, varying in orthographic complexity, frequency, and—for radicals—intercharacter frequency (the number of compound characters that contain the radical), was studied using an immediate free-recall task. When radicals or characters are relatively frequent, so that their pronunciations are well known by literate Chinese, they seem to be maintained in verbal form in short-term memory. For these stimuli, intercharacter frequency and complexity have relatively small influences on memory span. Stimuli low in frequency, with pronunciations that are not apt to be known, seem to be maintained in visual form in short-term memory. Memory span is much smaller for these stimuli and is influenced by both intercharacter frequency and complexity. Furthermore, short-term memory for relatively high-frequency characters is interfered with more by a verbal than by a visual intervening task, whereas the opposite is true for low-frequency characters.  相似文献   
59.
Wistar rats of three age groups were tested in an automated tunnel-maze system of variable geometry to investigate whether changes in spontaneous locomotor activity and in learning and memory develop differentially or in a correlated fashion as a function of age. Senescent (30 months) as well as mature-adult (17 months) rats showed an age-correlated decline of locomotor activity as compared to the mature-young (5 months) group. Both working-memory (measured as within-trial arm discrimination performance) and reference-memory (measured as avoidance of "blind alley" visits) were severely affected in the senescent group, whereas the middle-aged animals suffered only from a working-memory deficit. The findings provide evidence that locomotor deficits do not necessarily interfere in the assessment of age-related changes in cognitive performance. Furthermore the results support the hypothesis that working and reference memory have different underlying physiological correlates and that these neuronal systems are differentially affected by the aging process.  相似文献   
60.
Serotonergic and opiate interactions in the modulation of drug- and environmental-induced analgesia were assessed in 6-day-old Sprague-Dawley-derived rat pups using tail-flick testing procedures. In these experiments the serotonergic antagonist metergoline was observed to attenuate both the analgesia induced by the opiate agonist morphine and the analgesia induced by isolation from siblings and the dam, an environmental manipulation which has previously been shown to be associated with increases in opiate activity. In contrast, the opiate antagonist naloxone was observed to be ineffective in blocking not only analgesia induced by the serotonergic agonist quipazine, but also analgesia induced by long-term deprivation from the dam and food, a manipulation that has been previously reported to induce increases in serotonergic utilization. These results suggest that in the neonate, as in the adult, the serotonergic modulation of nociception appears to occur "downstream" from the opiate systems serving to regulate nociception following both drug- and environmental-induced alterations in pain sensitivity. Analgesia induced by long-term deprivation from food and the dam appears to be strongly related to increases in serotonergic activity and relatively unaffected by opiate antagonism, whereas analgesia induced by isolation from siblings and the dam may be related to increases in opiate activity, but modulated by serotonergic systems serving to regulate pain responsivity. Thus alterations in the environment, mediated at least in part by alterations in opiate and serotonergic activity, appear to play an important role in influencing the sensitivity of the neonate to pain stimuli.  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