全文获取类型
收费全文 | 37251篇 |
免费 | 1614篇 |
国内免费 | 26篇 |
出版年
2020年 | 408篇 |
2019年 | 484篇 |
2018年 | 706篇 |
2017年 | 734篇 |
2016年 | 755篇 |
2015年 | 578篇 |
2014年 | 632篇 |
2013年 | 2971篇 |
2012年 | 1152篇 |
2011年 | 1251篇 |
2010年 | 735篇 |
2009年 | 690篇 |
2008年 | 933篇 |
2007年 | 968篇 |
2006年 | 829篇 |
2005年 | 756篇 |
2004年 | 730篇 |
2003年 | 704篇 |
2002年 | 733篇 |
2001年 | 1360篇 |
2000年 | 1325篇 |
1999年 | 950篇 |
1998年 | 381篇 |
1997年 | 354篇 |
1996年 | 345篇 |
1992年 | 774篇 |
1991年 | 717篇 |
1990年 | 738篇 |
1989年 | 699篇 |
1988年 | 684篇 |
1987年 | 623篇 |
1986年 | 668篇 |
1985年 | 650篇 |
1984年 | 515篇 |
1983年 | 457篇 |
1981年 | 328篇 |
1979年 | 526篇 |
1978年 | 401篇 |
1977年 | 334篇 |
1976年 | 320篇 |
1975年 | 451篇 |
1974年 | 572篇 |
1973年 | 548篇 |
1972年 | 477篇 |
1971年 | 428篇 |
1970年 | 418篇 |
1969年 | 430篇 |
1968年 | 535篇 |
1967年 | 454篇 |
1966年 | 454篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
911.
912.
A general approach to confirmatory maximum likelihood factor analysis 总被引:17,自引:0,他引:17
K. G. Jöreskog 《Psychometrika》1969,34(2):183-202
We describe a general procedure by which any number of parameters of the factor analytic model can be held fixed at any values and the remaining free parameters estimated by the maximum likelihood method. The generality of the approach makes it possible to deal with all kinds of solutions: orthogonal, oblique and various mixtures of these. By choosing the fixed parameters appropriately, factors can be defined to have desired properties and make subsequent rotation unnecessary. The goodness of fit of the maximum likelihood solution under the hypothesis represented by the fixed parameters is tested by a large samplex
2 test based on the likelihood ratio technique. A by-product of the procedure is an estimate of the variance-covariance matrix of the estimated parameters. From this, approximate confidence intervals for the parameters can be obtained. Several examples illustrating the usefulness of the procedure are given.This work was supported by a grant (NSF-GB 1985) from the National Science Foundation to Educational Testing Service. 相似文献
913.
This study asked the question: What are the role expectancies of treatment personnel in the treatment community and are they consistent across patients' emotional condition? An 83-item inventory was developed and administered under three different sets of instructions, each characterizing a different patient condition. Treatment staff and administrators were asked to rate items on the basis of the level of expectancy they held for their team vocational rehabilitation counselor. The analyses suggest that treatment staff and counselors do not agree on role expectations and that patient condition is a significant mediating variable. 相似文献
914.
Mukul K. Dey 《Psychological research》1969,33(1):79-84
Summary Retroactive inhibition in free-recall learning was measured under six degrees of meaningful similarity: zero, low, low-medium, medium, medium-high, and high. For each degree of similarity, an experimental and a control group of 20 Ss each learned a list of 20 unrelated adjectives through three cycles of alternate study and unpaced free recall. Immediately thereafter, the experimental group learned a second list of 20 adjectives, while the control group rested. Finally, a single recall trial was administered to both groups to measure first-list retention. The results have revealed a relationship which is at variance with the relationships observed in both serial and paired-associate learning but conforms to the curvilinear function earlier formulated by Skaggs and Robinson. Fresh arguments are offered in defence of the Skaggs-Robinson hypothesis. 相似文献
915.
916.
Gerald B. Biederman 《Quarterly journal of experimental psychology (2006)》1969,21(4):322-329
In an experiment investigating the effect of CS duration on discriminated bar-press conditioning, subjects were assigned to one warning period duration (1.5, 5.0 or 15.0 sec.) on the first day of avoidance training, and to one of the three durations on the second day of training. On each day avoidance behaviour was greatly influenced by the duration of the CS (warning) period, but the duration on day I had no effect on the second day's avoidance performance. Groups receiving no CS during training, although provided an avoidance contingency, showed little conditioning, but produced highly significant amounts of intertrial responding. In a second experiment, subjects receiving CS on day I were shifted to no CS on day II. Avoidance performance on day II was not significantly different from the day II performance of subjects in Experiment I having two training sessions with the CS present or absent on both days. 相似文献
917.
Locomotor avoidance conditioning and locomotor food conditioning in male albino rats demonstrated that locking of temporary connections is accomplished by coupling of phases of different synchronized periodic neural processes. Phase coupling was verified by the formation of parallel periodic courses of reaction times and motor reaction times in the process of elaboration of conditional avoidance reflexes, and by the curve of the corresponding correlation coefficients, which were calculated from the reaction times and motor reaction times in food conditioning measured every day during the period of stabilization. The authors hold the view that a locking mechanism based on the synchronization of periodic processes in conditioning is most compatible with efficient formation of conditional reflexes and can promote adaptation. Furthermore, it is assumed that information storage, too, occurs periodically, according to the principle of rotary storage. 相似文献
918.
K. Lissák 《Integrative psychological & behavioral science》1969,4(3):145-154
Recent observations on the plasticity of brain and behavior relationships indicate that the temporary connections between environmental and neuroanatomical substrates have tremendous specificity but at the same time are very plastic. Establishment of a conditional reflex by stimulation of the hippocampal pyramidal layer and/or the mesencephalic reticular formation did not interfere with the differential stimulation of very near points in the same structures. These correlations between brain and behavior confirmed the earlier belief that the development of temporary connections between environment and brain is an elementary process of the central nervous system. Complex behavioral functions are organized through both neuronal and humoral afferentation. Data accumulated recently indicate that the descending forebrain influence is inhibitory in the brain stem and diencephalon and controls the sensory input in a somatomotor-specific and situation-specific manner. Humoral factors affecting thresholds can change the dynamic equilibrium existing between ascending excitatory and descending inhibitory systems; these alterations always follow the rule of situation and somatomotor specificity. 相似文献
919.
A professional school counselor key was developed on the Strong Vocational Interest Blank using Campbell's revised procedures. Of the 403 counselors initially contacted, 340 responded. Of this number, 203 were identified as professional counselors and were included in the professional school counselor scale. Each of these individuals was fully certified, possessed three or more years' experience as a counselor, was a member of a professional guidance association, and was thoroughly satisfied with his job as a counselor. Differences between professional counselors and non-professional counselors seemed to indicate a greater people-orientation in the professional counselor group. This was further supported by relationships of the professional counselor key with other scales on the SVIB. 相似文献
920.
The effects of incidental stimuli, defined as visual stimuli not under verbal control, upon a selection task were observed as a function of feedback contingency. Ss judged letter pairs to be valid or invalid completions of preceding letter parts. During the presentation of the letter parts, the response pair or an alternative pair of letters was intermittently presented at a threshold value individually determined for each S. One group of Ss received a light feedback of performance contingent upon responding to the incidental stimuli; whereas a second group received a random noncontingent feedback. The results indicated: (a) both groups responded to the incidental stimuli; (b) feedback contingency had no effect on frequency of responding to the incidental stimuli; (c) frequency of responding to the incidental stimuli remained constant over 32 trials. 相似文献