全文获取类型
收费全文 | 19148篇 |
免费 | 805篇 |
国内免费 | 7篇 |
专业分类
19960篇 |
出版年
2020年 | 230篇 |
2019年 | 226篇 |
2018年 | 380篇 |
2017年 | 331篇 |
2016年 | 367篇 |
2015年 | 270篇 |
2014年 | 323篇 |
2013年 | 1393篇 |
2012年 | 603篇 |
2011年 | 545篇 |
2010年 | 372篇 |
2009年 | 362篇 |
2008年 | 494篇 |
2007年 | 523篇 |
2006年 | 448篇 |
2005年 | 439篇 |
2004年 | 383篇 |
2003年 | 328篇 |
2002年 | 357篇 |
2001年 | 787篇 |
2000年 | 745篇 |
1999年 | 524篇 |
1998年 | 200篇 |
1997年 | 195篇 |
1996年 | 198篇 |
1992年 | 414篇 |
1991年 | 403篇 |
1990年 | 399篇 |
1989年 | 345篇 |
1988年 | 346篇 |
1987年 | 336篇 |
1986年 | 299篇 |
1985年 | 312篇 |
1984年 | 294篇 |
1983年 | 244篇 |
1982年 | 206篇 |
1979年 | 272篇 |
1978年 | 225篇 |
1977年 | 197篇 |
1976年 | 172篇 |
1975年 | 249篇 |
1974年 | 284篇 |
1973年 | 282篇 |
1972年 | 227篇 |
1971年 | 231篇 |
1970年 | 180篇 |
1969年 | 211篇 |
1968年 | 257篇 |
1967年 | 246篇 |
1966年 | 196篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
54.
T D Crespi 《Adolescence》1988,23(92):805-811
The effectiveness of a time-out intervention for adolescent psychiatric patients, adjudicated (delinquent) youth, and behaviorally disordered youngsters was explored in this study. The research was conducted in three psychiatric hospitals for children and adolescents, a facility for adjudicated youth, and in a day-treatment program. Utilizing a comparative outcome model, 813 occurrences of time-out with 274 youth were investigated in order to assess levels of effectiveness. The results indicated that time-out had a significant impact, and the use of a child-care specialist as time-out monitor improves overall effectiveness. Important implications for practicing professionals and clinical researchers are noted. 相似文献
55.
H. O. F. Veiel G. Brill H. Hafner R. Welz 《American journal of community psychology》1988,16(6):839-861
The social support patterns of a sample of 101 suicide attempters were compared with the patterns of a control sample on the basis of structured interview data. Network characteristics and the extent of support in different functional categories were examined as to their absolute and relative power to discriminate between the suicide attempters and the controls. A clear separation of the functions of kin and of friends/acquaintances emerged. The crucial difference between the attempters and the controls lay in the number of friends with whom the subjects had agreeable everyday interactions and in the number of kin that provided crisis support, both psychological and instrumental. Other support differences between the two groups were of secondary importance. While there was no overall difference in the frequency of social interactions between the two groups, the size of the social network differed greatly. Consequences for the conceptualization and measurement of social support as well as for the prevention of suicidal behavior are discussed. 相似文献
56.
57.
The possibility that rats can navigate in the Morris water maze by reducing the difference between the memorized platform scene and the current sensory input was tested in nine blind rats. A computerized videosystem monitored the rats' movements in the pool and converted the rat-target distance into tones the frequency of which increased in 64 equal steps from 120 Hz at 128 cm to 7680 Hz at 0 cm. During 15 days of training to find a fixed platform position from different starting points (12 trials per day) average escape latencies decreased from 39.0 to 25.4 s. The performance significantly deteriorated when the acoustic distance signalization was omitted and/or when the target position was changed form trial to trial. It is concluded that blind rats solved the task by simultaneously employing search strategy based on position responses, mapping using acoustic background beacons, and distance reduction navigation. It is argued that the various strategies are additive and that their relative significance depends of the conditions of the experiment. 相似文献
58.
M J Nissen J L Ross D B Willingham T B Mackenzie D L Schacter 《Brain and cognition》1988,8(1):117-134
We studied an individual with multiple personality disorder in whom each of several personalities claimed to have no direct awareness of the others and to be unable to consciously remember the experiences of other personalities. A broad selection of implicit and explicit memory tests was used to determine the extent to which one personality had access to knowledge acquired by another and the circumstances in which that knowledge would be expressed. The implicit assessment of memory was a necessary but not sufficient condition for demonstrating interpersonality access. The degree of compartmentalization of knowledge in this patient depended largely on whether the interpretation of presented information was likely to differ across personalities. 相似文献
59.
Studies of psychosocial influences on coronary artery atherogenesis in cynomolgus monkeys 总被引:1,自引:0,他引:1
The cynomolgus macaque provides a suitable primate model for studying how psychosocial factors contribute to coronary artery atherogenesis. Important interactions with diet, sex, and behaviorally elicited cardiovascular reactivity are described. 相似文献
60.
Despite widespread popular belief in the activation of recurrent lesions in genital herpes simplex virus (HSV) by psychosocial stress, little empirical evidence supports that contention. This study retrospectively examined the role of stress in activation of HSV lesions as mediated by social support. Participants were 59 volunteers who had self-reported culture-positive genital HSV for at least 10 months. Measures of stress proneness (State-Trait Anxiety Inventory; STAI-Trait), recent stressful events (Schedule of Recent Events; SRE), and subjective appraisal of stress (global self-rating) were administered along with measures of general social support and herpes-specific social support. When retrospective reports of HSV symptoms were examined using a multiple-regression approach, duration of disease and amount of herpes-specific social support were found to be significant moderators of the relation between stress and number of HSV recurrences in the preceding 12 months. When duration of disease was short (less than 4 years), stress (SRE) and number of recurrences were positively associated; when disease duration was longer, there was no relationship. Similarly, at low levels of herpes-specific social support, a positive relation between stress (SRE) and number of recurrences was found. However, at higher levels of herpes-specific social support, no association was found. No relation was found between stress proneness (STAI-Trait) and HSV symptoms. However, subjective appraisal (global rating) of stress in the preceding 12 months was positively and significantly correlated with reported number of recurrences. Results are discussed in terms of their clinical implications. 相似文献