全文获取类型
收费全文 | 73831篇 |
免费 | 1387篇 |
国内免费 | 7篇 |
专业分类
75225篇 |
出版年
2020年 | 775篇 |
2019年 | 935篇 |
2018年 | 1254篇 |
2017年 | 1320篇 |
2016年 | 1407篇 |
2015年 | 1004篇 |
2014年 | 1222篇 |
2013年 | 5407篇 |
2012年 | 2223篇 |
2011年 | 2217篇 |
2010年 | 1456篇 |
2009年 | 1341篇 |
2008年 | 2008篇 |
2007年 | 2005篇 |
2006年 | 1769篇 |
2005年 | 1626篇 |
2004年 | 1506篇 |
2003年 | 1414篇 |
2002年 | 1448篇 |
2001年 | 2215篇 |
2000年 | 2104篇 |
1999年 | 1624篇 |
1998年 | 743篇 |
1997年 | 677篇 |
1996年 | 665篇 |
1992年 | 1467篇 |
1991年 | 1321篇 |
1990年 | 1360篇 |
1989年 | 1199篇 |
1988年 | 1239篇 |
1987年 | 1165篇 |
1986年 | 1216篇 |
1985年 | 1238篇 |
1984年 | 1009篇 |
1983年 | 968篇 |
1982年 | 694篇 |
1979年 | 1161篇 |
1978年 | 784篇 |
1977年 | 738篇 |
1976年 | 700篇 |
1975年 | 958篇 |
1974年 | 1091篇 |
1973年 | 1153篇 |
1972年 | 928篇 |
1971年 | 892篇 |
1970年 | 849篇 |
1969年 | 887篇 |
1968年 | 1126篇 |
1967年 | 1007篇 |
1966年 | 874篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
Sources of difficulty in deductive reasoning: The THOG task 总被引:2,自引:0,他引:2
David P. O'Brien Ira A. Noveck George M. Davidson Shalom M. Fisch R. Brooke Lea Jason Freitag 《The Quarterly Journal of Experimental Psychology Section A: Human Experimental Psychology》1990,42(2):329-351
The THOG task presents four designs constructed from two shapes and two colours. Subjects are told that the experimenter has written down one of the shapes and one of the colours and are provided the rule that if, and only if, any design has either the shape or the colour, but not both, written down, then it is a THOG. Finally, they are given an exemplar and are asked to classify the remaining designs. Successful solution requires construction of hypotheses, reasoning under each hypothesis, and comparison of the results under each to reach a final conclusion. Few subjects are able to provide adequate responses on the standard version of the task. We present the results of four experiments, with 160 undergraduates each presented with one of eight versions of the task. Experiments 1 and 2 indicate that (1) some subjects think that the properties that are written down are identical to those of the exemplar, although these are not the same subjects who exhibit the modal error pattern, (2) many subjects correctly understand the disjunction of the rule but fail to consider the hypotheses, and (3) poor initial encoding of the problem is not easily corrected. Experiment 3 investigates the sufficiency of the claim of Griggs and Newstead (1982) that appropriate problem solution follows from explicit presentation of all problem information (including use of positive labels for properties that are not written down), and Experiment 4 investigates the necessity of the claim. The results of Experiments 3 and 4 show that presenting positive category labels does increase the frequency of correct solution; however, positive category labels are not necessary for such improvement. Separation of the labels of the THOG rule from those of the exemplar, or informing subjects that only one other design is a THOG, also increases the frequency of successful solution. The results suggest that many people have some fairly sophisticated reasoning skills. but application of these skills is easily discouraged when the features of the task lead to poor initial encoding. 相似文献
902.
Marked differences in detectability as a function of spatial location, a "detectability gradient," are observed when subjects are required to detect a briefly exposed target pattern of uncertain location in the presence of a number of nontarget patterns. Target detectability also is inversely related to the number of nontarget patterns which are present in this search paradigm. These previous findings provide strong evidence for a serial process in which increasing probability of error occurs during a scan of a rapidly degrading neural representation of the visual image following a brief exposure to the stimuli. It is not yet established whether this scan is attentional or perceptual in nature. The present experiments test the hypothesis of an attentional scan by presenting the target and nontarget patterns in spatially segregated groups. If the scan is attentional, then target detectability under these circumstances would be expected to exhibit the characteristic phenomenon of "group processing"--a close clustering of detection performance for targets located within a group and large differences in detectability across groups. As no evidence for group processing was observed, the results fail to support the view that the scan is attentional in nature but are fully consistent with a nonattentional scan. 相似文献
903.
Permanent disruption of aspects of a highly learned skill such as walking force adaptations to occur to the movement. Firstly the body must determine what factors will guide the formation of the new walking pattern, and secondly that new movement pattern must be learned. Frequently the questionable assumption is made that the performance objectives of the new skill are the same as the original. This work used non-linear optimal control and multiple segment simulation to evaluate the ability of several possible objective functions to predict pathological walking patterns. These predictions were then also compared to the results from normal walking. Preliminary results indicate the performance objectives of pathological gaits may be quite different from those of normals. Some support was also provided for the existence of simultaneous multiple performance objectives in complex movements. 相似文献
904.
Compared individuals at high versus average risk for colorectal cancer (CRC) with respect to factors they cited as affecting their risk of developing CRC. We also examined the relationship of these risk-factor perceptions to perceived susceptibility and participation in a CRC screening test. All individuals in the high-risk group were informed that, as a sibling of someone with CRC, they were more likely to get this cancer themselves. We found minimal differences among siblings with respect to perceived susceptibility. Further, although high-risk siblings were more likely to participate in screening, only 20.2% cited heredity as a risk-increasing factor, and, among these siblings, there was no relationship between screening participation and the citation of any specific risk factors, including heredity. These findings demonstrate the need for more research examining how high-risk individuals process risk-relevant information and the effect of this information on health behavior. 相似文献
905.
The present study used a multitrait-multimethod technique [D.T. Campbell and D. W. Fiske (1959) “Convergent and Discriminant Validation by the Multitrait-Multimethod Matrix,” Psychological Bulletin, 56, 81–105] to examine Bem's [(1974) “The Measurement of Psychological Androgyny,” Journal of Consulting and Clinical Psychology, 42, 152–162] use of an instrumental-expressive dichotomy to conceptualize the Masculinity and Femininity scales of the Bem Sex Role Inventory as statistically orthogonal constructs. Results indicate that while perhaps reliable, masculinity and femininity lack clear convergent and discriminant validity. Therefore, Bem's contention that masculinity and femininity are orthogonal constructs is questioned. Results are discussed in light of trait- vs. method-driven research. 相似文献
906.
R J Leonesio T O Nelson 《Journal of experimental psychology. Learning, memory, and cognition》1990,16(3):464-467
We compared the predictions from several kinds of metamemory judgments (on the same set of items), both in terms of their predictive accuracy and in terms of the commonality of predictions. Undergraduates made judgments about the ease with which they could learn each item in a list (ease-of-learning judgments); then they learned every item, either to a minimal criterion of learning or with overlearning, and made judgments about how well they knew each item (judgments of knowing); finally, they returned 4 weeks later for a retention session and made feeling-of-knowing judgments on every time they could not recall, after which a recognition test assessed predictive accuracy. Ease-of-learning judgments had the least predictive accuracy. Surprisingly, however, the recognition of nonrecalled items was predicted equally well by judgments of knowing (made 4 weeks earlier) as by feeling-of-knowing judgments (made immediately prior to recognition). Moreover, those two kinds of judgments were only weakly correlated with each other, which implies that they do not tap memory in the same way. 相似文献
907.
Recent research on the Ms. stereotype suggests a potentially important exception to the strong link between gender and managerial stereotypes observed in the 1970s. Specifically, we hypothesized that a woman who prefers “Ms.” as her title of address would be seen by perceivers of both sexes as more similar in the “requisite” traits of a successful, middle manager than would a woman who prefers a traditional title of address for herself. These hypotheses were tested by having respondents rate a “successful, middle manager” or other stimulus persons varying in titles of address, sex, and marital status. Correlational analyses of respondents' ratings of stimulus persons yielded strong support for the hypotheses. That is, a woman preferring Ms. as her title of address was seen by adult perceivers of both sexes as possessing the “requisite” personality characteristics of a successful, middle manager; whereas a traditionally titled woman was not. Implications of these findings are discussed. 相似文献
908.
It was hypothesized that older widows (N=309) who had been care givers to their husbands would have undertaken a greater number of household responsibilities than had women who had not been care givers. Findings indicated that, prior to the husband's death, more traditionally male and more traditionally female tasks were performed by the care-giving wives (n=158). This was particularly true in the case of Alzheimer's care givers (n=21). More importantly, widows' present feelings of competence were related to undertaking household responsibilities, with those who had been care givers expressing significantly higher levels of competence. 相似文献
909.
Marnie E. Rice Vernon L. Quinsey Randerson Houghton 《Behavioral sciences & the law》1990,8(3):313-326
The relationship between program performance and outcome for patients in maximum security token economy programs has not been previously studied. We examined variables related to success in a token economy program and to postrelease failure for 92 men in a maximum security psychiatric hospital. Point earnings later in the program were best predicted by earlier point earnings. Variables that best predicted postrelease failure, defined in various ways, were similar to those found in other studies; youthfulness, having spent more time in institutions, a diagnosis of personality disorder or retardation rather than psychosis, not having been found not guilty by reason of insanity or unfit to stand trial, and having been referred from another psychiatric hospital. That program variables were generally unrelated to later outcome suggests that treatment programs for patients in maximum security settings must emphasize skills that are relevant to postrelease success. 相似文献
910.
This experiment compared the extent to which students learned facts included in computer-based-training frames that required
an overt response to those that did not. Frames included two types of facts: Some facts had one word missing which had to
be supplied by the student (active facts). Other facts had no missing words and required no overt response (passive facts).
Each student completed four 14-fact modules in random order. Two of the modules contained frames with all active facts. Each
frame in the other two modules contained one active and six passive facts. Paper pretests and posttests showed that students
learned twice as many facts when all facts in the module were active than when only one in seven were active. The modules
that included passive facts required one-fifth the time to complete than those with only active facts. Students learned more
facts per minute of training in one of the two modules that included passive facts than in the two modules with only active
facts. 相似文献