全文获取类型
收费全文 | 55309篇 |
免费 | 668篇 |
国内免费 | 2篇 |
专业分类
55979篇 |
出版年
2020年 | 391篇 |
2019年 | 551篇 |
2018年 | 3972篇 |
2017年 | 3373篇 |
2016年 | 2840篇 |
2015年 | 717篇 |
2014年 | 688篇 |
2013年 | 2984篇 |
2012年 | 1564篇 |
2011年 | 3406篇 |
2010年 | 3104篇 |
2009年 | 2152篇 |
2008年 | 2619篇 |
2007年 | 2985篇 |
2006年 | 910篇 |
2005年 | 961篇 |
2004年 | 881篇 |
2003年 | 856篇 |
2002年 | 735篇 |
2001年 | 1268篇 |
2000年 | 1264篇 |
1999年 | 883篇 |
1998年 | 432篇 |
1997年 | 355篇 |
1996年 | 330篇 |
1995年 | 318篇 |
1994年 | 327篇 |
1992年 | 748篇 |
1991年 | 719篇 |
1990年 | 687篇 |
1989年 | 628篇 |
1988年 | 606篇 |
1987年 | 603篇 |
1986年 | 571篇 |
1985年 | 633篇 |
1984年 | 502篇 |
1983年 | 400篇 |
1979年 | 482篇 |
1978年 | 359篇 |
1977年 | 345篇 |
1976年 | 320篇 |
1975年 | 426篇 |
1974年 | 433篇 |
1973年 | 484篇 |
1972年 | 390篇 |
1971年 | 323篇 |
1969年 | 335篇 |
1968年 | 387篇 |
1967年 | 336篇 |
1966年 | 387篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
To test the generality, across modality and across species, of a bidirectional effect of photic stimulation in infant rats found in previous experiments, two experiments examined the effects on heart rate (HR) of onset and offset of auditory stimulation in rats and of photic stimulation in guinea pigs. Experiment 1 demonstrated a unidirectional, decelerative response in rats 17 and 21 days of age to the onset and offset of a 1-kHz tone, at both low (80 dB) and high (100 dB) intensity levels and at 14 days to the onset of the high-intensity tone. Experiment 2 demonstrated that infant guinea pigs, which unlike infant rats are precocial and not nocturnal, responded to the offset but not to the onset of light, and that this response was decelerative. These results indicated a lack of generality of the bidirectional HR effect, and were discussed in terms of the orienting/defensive reflex distinction. 相似文献
142.
143.
S C Wilhite 《The American journal of psychology》1985,98(1):41-58
This experiment compared the effects of high-level and low-level postpassage questions, when presented immediately after the passage segment containing the answer to the question, on college students' free recall of expository prose passages. Low-vocabulary subjects' recall of high-level information not specifically quizzed by the postpassage questions was significantly greater in the condition in which the questions quizzed a high-level unit than in the low-question and no-question conditions, p less than .05. These results are interpreted as being consistent with a direct-access explanation which assumes that questions presented in close temporal contiguity to the quizzed information directly access that information in memory and that fewer associative links have to be traversed in the spread of activation from high-level units to other related information in the hierarchy. The effect of type of question in this experiment was compared with that found in an earlier experiment (Wilhite, 1982) involving delayed question presentation. 相似文献
144.
This study concerns the manner in which the traumatic events suffered by the parent in the Nazi holocaust are communicated to the second generation born after the Second World War. Additionally we investigated the effects of differences in wartime experiences on subsequent communication behaviors. Communication behaviors in families whose parents had been prisoners in concentration camps were compared with those of families who had displayed active resistance (i.e., were partisans) during the Second World War. The data indicate greater legitimacy and openness in discussing holocaust-related issues in the homes of ex-partisans than in the homes of ex-prisoners in concentration camps. Also, sons and daughters of the former group have better knowledge of the holocaust and hold more favorable attitudes than do sons and daughters in the second group. The implications of these findings are discussed. 相似文献
145.
146.
Administered the Indian adaptation of the Rosenzweig P-F Study to 144 Scheduled Caste (SC) adolescent and 158 young adult male Indians. The results show that SC adolescents scored significantly higher on ego-defensive (ED) and extragressive (EA) and lower on need-persistive (NP), introgressive (IA) and imgressive (MA) reactions as compared to the Non-Scheduled caste (Non-SC) adolescents while there was no significant difference on any reaction among SC and Non-SC young adults. SC adolescents scored higher on NP and lower on obstacle-dominance (OD) reaction as compared to the SC young adults. Non-SC young adults were higher on EA, ED, and OD and lower on IA and NP as compared to those of adolescents. The pattern of reactions was ED-EA-NP-IA-MA-OD among adolescents and ED-EA-IA-NP-MA-OD among young adults of both the castes. 相似文献
147.
Memory deficits and memory surfeits: differential cognitive consequences of tokenism for tokens and observers 总被引:1,自引:0,他引:1
Historically, women and minority group members have been underrepresented in the professions and in better paying, high-status jobs. Even when they have been admitted to such positions, these underrepresented persons often have been the only member of their social category: a token. Previous field and laboratory research has shown that "tokens" attract disproportionate attention and are either evaluated unfairly or evaluated on the basis of their normal reactions to differential treatment by majority group members. We tested the possibilities of whether tokens might suffer more cognitive deficits than would nontokens, and whether they do so even when they are treated no differently. College students were led to believe that they were sharing their views on everyday topics with three other students (actually videotaped confederates), who were either all of the student's own sex or all of the opposite sex. In a later memory test, token participants remembered fewer of the opinions that they and the three other students had expressed than did nontokens. Observers, in contrast, remembered more of what token subjects said than what the three other students said. Theoretical and public policy implications are discussed. 相似文献
148.
R T Brown K A Borden R Schleser S Clingerman S Orenczuk 《The Journal of genetic psychology》1985,146(4):535-540
The present study was designed to investigate whether a specific subgroup of learning-disabled children (attention-deficit-disordered, ADD) differed from their normal counterparts on Piagetian tasks of conservation. The subjects were 34 third-and fourth-grade children. Seventeen children had been diagnosed as ADD; the remaining half were designated as normal. The two groups were equivalent in chronological age, mental age, and intelligence. The results indicated significant differences between the two groups on tasks tapping conservation of substance and number. These results may support the theory of a lag in the development of conservation in children with specific learning disabilities (ADD). Implications of the present research for therapeutic and remedial programs that serve ADD children are also discussed. 相似文献
149.
The study examined the contribution of various aspects of pattern complexity to children's difficulty on reconstruction of patterns. Specifically, diagonal pattern components and spatial orientation of patterns were considered. Twenty-four children between 16 months and 31 months were presented eight 5-square patterns on a 3 X 3 matrix of squares. The squares lighted, went dark, and then could be relighted by the child if touched. Accuracy of reconstruction was determined by the number of squares correctly chosen by the child during reconstruction. The eight patterns were rated according to Leeuwenberg's code length method, Garner's rotation-and-reflection method, Halford and Macdonald's rating scale, and a simple count of the number of diagonal lines. Analysis of children's responding indicated that number of diagonal lines was more predictive of memory performance than the other three rating systems, implying that diagonality is an important feature of pattern complexity that should be included in ratings of patterns used in research with children. 相似文献
150.
A R Davidson S Yantis M Norwood D E Montano 《Journal of personality and social psychology》1985,49(5):1184-1198
The synthesis of two separate lines of inquiry--research on information integration and longitudinal studies of attitudes--prompted the hypothesis that the degree of consistency between attitudes and behavior will increase as a function of the amount of information available about the attitude object. The hypothesis was tested in three separate longitudinal studies, ranging in length from 4 days to 4 months, that investigated the following behaviors: voting for candidates for political office, voting for two social policy election initiatives, and having an influenza vaccination. In support of the hypothesis, in each study, amount of information moderated the consistency between attitudes and behavior; and the significance of this relation remained even after controlling for the effects of a number of other potential moderators, including prior direct behavioral experience with the attitude object and attitude certainty. Consistent with previous research, direct behavioral experience was also a determinant of attitude-behavior consistency, and for the behavior of having an influenza vaccination, this relation was independent of the effect of amount of information. The discussion focuses on the interrelation among moderators of attitude-behavior consistency and on the theoretical implications of the findings. 相似文献