全文获取类型
收费全文 | 80325篇 |
免费 | 1306篇 |
国内免费 | 4篇 |
专业分类
81635篇 |
出版年
2020年 | 587篇 |
2019年 | 791篇 |
2018年 | 4186篇 |
2017年 | 3554篇 |
2016年 | 3173篇 |
2015年 | 1008篇 |
2014年 | 1040篇 |
2013年 | 4527篇 |
2012年 | 2313篇 |
2011年 | 4090篇 |
2010年 | 3517篇 |
2009年 | 2549篇 |
2008年 | 3238篇 |
2007年 | 3674篇 |
2006年 | 1612篇 |
2005年 | 1586篇 |
2004年 | 1449篇 |
2003年 | 1328篇 |
2002年 | 1376篇 |
2001年 | 2012篇 |
2000年 | 2018篇 |
1999年 | 1502篇 |
1998年 | 730篇 |
1997年 | 640篇 |
1996年 | 632篇 |
1993年 | 559篇 |
1992年 | 1252篇 |
1991年 | 1152篇 |
1990年 | 1137篇 |
1989年 | 1033篇 |
1988年 | 1020篇 |
1987年 | 975篇 |
1986年 | 1045篇 |
1985年 | 1056篇 |
1984年 | 886篇 |
1983年 | 810篇 |
1982年 | 569篇 |
1981年 | 568篇 |
1979年 | 946篇 |
1978年 | 675篇 |
1975年 | 774篇 |
1974年 | 820篇 |
1973年 | 920篇 |
1972年 | 773篇 |
1971年 | 730篇 |
1970年 | 652篇 |
1969年 | 670篇 |
1968年 | 859篇 |
1967年 | 782篇 |
1966年 | 656篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
251.
Flicker fusion frequencies of 48 healthy controls and of 35 alcoholics were measured to detect possible associations between flicker fusion and signs of nonspecific brain damage, the aim of the study. FFF was statistically significantly lower in patients addicted to alcohol than in healthy subjects. Lower flicker fusion frequencies were associated with the severeness of organic psychosis as rated psychopathologically. The hypothesis that addiction to alcohol is a sign of diffuse, nonspecific, organic brain damage was discussed. 相似文献
252.
The Safety Locus of Control Scale was designed to predict employees' accidents and injuries. Internal scorers think they should assume personal responsibility for their safety, and they believe they can take preventive steps to avoid accidents. External scorers assume little personal responsibility for prevention of accidents. Instead, they place more blame on factors outside their control, such as luck or chance. This study showed that the safety scale was effective in differentiating between groups with varying accident histories, which supports the criterion-related validity of the scale. 相似文献
253.
Subjects in a prior study of complex learning often experienced difficulty in mastering the task because of an apparent reluctance to release one perceptual field and reconstrue the task on a higher cognitive level. It was hypothesized that were this the correct explanation, the faster learners would be more field independent on a measure of field dependence, since independence has been defined in terms of ease in releasing one's attention from the immediate perceptual field. This hypothesis was tested with 22 undergraduate subjects for whom Group Embedded Figures Test scores were correlated with the number of trials to completion on the complex learning task. A moderate but significant correlation supported the hypothesis. 相似文献
254.
A property of attitudes, namely, the fact that attitudes select facts, is used to comment upon a paper on handedness and career choice. 相似文献
255.
Cross-language evidence for three factors in speech perception 总被引:4,自引:0,他引:4
256.
The authors present a short review of the pertinent literature and report on their own neuropsychiatric findings following internal craniocerebral injuries, at the same time drawing attention to the necessity of psychological examination. Statistical comparisons with the international literature are complicated owing to the different classifications used for craniocerebral injuries. 相似文献
257.
Hyperlexia and a variant of hypergraphia 总被引:1,自引:0,他引:1
A patient with hyperlexia and hypergraphia is described. The unusual co-occurrence of these two abilities is discussed. Hyperlexia may provide a useful marker to guide educational programming. 相似文献
258.
This project studied the effects of weather variables and size of the population on minor and major violence rates within six prisons in the Kingston, Ontario, Canada area from January, 1980 through December, 1983. While weather variables have been studied in relation to mood changes within the general population, this study was the first to analyze the impact of weather variables on rates of violence within the prison setting using forward inclusion multiple regression. Analysis showed that population size consistently appeared positively correlated with assaults on other inmates among the male medium-security prisoners during the summer months. In the summer months, temperature tended to be positively related to some minor kinds of offenses, but in the winter months the relationship was negative. Humidity, rain, sunshine hours, snow, and snow on the ground were not consistently related to incidences of minor and major violence. Indices of geomagnetic disturbances had statistically significant inverse relationships with attempted suicide/self-inflicted injury rates among the male prisoners during the summer months. Over 12 months, wind was generally negatively correlated with incidences of major and minor violence among the male inmates. For 6-mo. periods, wind was generally positively correlated with violence rates during the winter months and negatively correlated during the summer months among the male inmates. The findings relating weather variables to violence rates in the women's prison were consistently in opposition to those found for male prisoners during the 4-yr. period. 相似文献
259.
S J Dollinger 《Perceptual and motor skills》1985,61(1):83-86
A paradoxical instruction was used to treat a 10-yr.-old boy's complaint of crying when unable to sleep and the daytime equivalent of fearing the public display of crying when failing at sports performances. The instruction resolved both the sleep disturbance and the public crying. The results suggest that, like adults, children may experience anxiety about sleep difficulties and that paradoxical intention may have promise for the treatment of some children's insomnia. 相似文献
260.
The relationship between cognitive style and illusion magnitude was examined using the assimilation and contrast Delboeuf distortions. As in previous research, field dependence correlated positively with assimilation; however, a significant negative correlation with contrast was also found, suggesting that, while field dependence may involve the illusory integration of the stimulus field, field independence may involve its equally illusory differentiation. 相似文献