全文获取类型
收费全文 | 8242篇 |
免费 | 440篇 |
国内免费 | 127篇 |
专业分类
8809篇 |
出版年
2023年 | 59篇 |
2022年 | 53篇 |
2021年 | 78篇 |
2020年 | 137篇 |
2019年 | 141篇 |
2018年 | 154篇 |
2017年 | 154篇 |
2016年 | 134篇 |
2015年 | 94篇 |
2014年 | 106篇 |
2013年 | 341篇 |
2012年 | 111篇 |
2011年 | 78篇 |
2010年 | 71篇 |
2009年 | 111篇 |
2008年 | 111篇 |
2007年 | 120篇 |
2006年 | 116篇 |
2005年 | 96篇 |
2004年 | 69篇 |
2003年 | 69篇 |
2002年 | 48篇 |
2001年 | 48篇 |
2000年 | 38篇 |
1999年 | 47篇 |
1998年 | 29篇 |
1997年 | 16篇 |
1996年 | 32篇 |
1995年 | 22篇 |
1994年 | 11篇 |
1993年 | 15篇 |
1992年 | 23篇 |
1991年 | 11篇 |
1990年 | 15篇 |
1989年 | 18篇 |
1988年 | 10篇 |
1987年 | 11篇 |
1985年 | 460篇 |
1984年 | 590篇 |
1983年 | 506篇 |
1982年 | 568篇 |
1981年 | 546篇 |
1980年 | 537篇 |
1979年 | 477篇 |
1978年 | 528篇 |
1977年 | 419篇 |
1976年 | 405篇 |
1975年 | 332篇 |
1974年 | 341篇 |
1973年 | 288篇 |
排序方式: 共有8809条查询结果,搜索用时 15 毫秒
51.
Ronald L. Numbers 《Zygon》1987,22(2):133-164
Abstract. As the crusade to outlaw the teaching of evolution changed to a battle for equal time for creationism, the ideological defenses of that doctrine also shifted from primarily biblical to more scientific grounds. This essay describes the historical development of "scientific creationism" from a variety of late–nineteenth– and early–twentieth–century creationist reactions to Charles Darwin's theory of evolution, through the Scopes trial and the 1960s revival of creationism, to the current spread of strict creationism around the world. 相似文献
52.
W V Dube W J McIlvane H A Mackay L T Stoddard 《Journal of the experimental analysis of behavior》1987,47(2):159-175
In an arbitrary matching-to-sample procedure, two mentally retarded subjects learned conditional discriminations with two sets of stimuli. Each set included a spoken name (N1 or N2), an object (O1 or O2), and a printed symbol (S1 or S2). One subject selected conditionally (a) O1 upon N1, and O2 upon N2, and (b) S1 upon O1, and S2 upon O2. The other subject selected conditionally (a) S1 upon N1, and S2 upon N2, and (b) O1 upon S1, and O2 upon S2. For both subjects, selections of O1 and S1 produced one type of food, F1; selections of O2 and S2 produced a different type of food, F2. Both subjects also learned identity-matching performances, selecting O1, O2, S1, S2, F1, and F2 conditionally upon those stimuli as samples; F1 followed selections of O1, S1, and F1; F2 followed selections of O2, S2, and F2. Matching performances consistent with stimulus class formation involving the names, objects, symbols, and foods were demonstrated on probe trials, even though these performances had not been taught explicitly. Next, new objects, X1 and X2, were presented on identity-matching trials, producing F1 and F2, respectively. Without further training, X1 was selected conditionally upon N1, S1, and O1, and X2 was selected upon N2, S2, and O2. When the contingencies were changed so that selections of X1 and X2 were now followed by F2 and F1, respectively, X2 was selected conditionally upon N1, S1, and O1, and X1 was selected upon N2, S2, and O2. Class membership of X1 and X2 had apparently changed. This study provides evidence that reinforcers may become members of stimulus classes, and that new stimuli may become class members through relations with reinforcers. 相似文献
53.
The interaction of stimulus and reinforcer control in complex temporal discrimination. 总被引:2,自引:2,他引:0
Six pigeons were trained in a discrete-trials signal-detection procedure to discriminate between a fixed-duration stimulus (5 s or 20 s) and a set of variable durations ranging from 2.5 s to 57.5 s in steps of 5 s. For each fixed-duration stimulus, the ratio of reinforcer frequencies contingent upon reporting the fixed versus the variable stimulus was systematically manipulated. Detection performance was well controlled by both the stimulus value and the reinforcer ratio. Both the discriminability between the fixed duration and the set of variable durations, and the discriminability between the fixed duration and each of the variable durations, were independent of the reinforcer-frequency ratio when discriminability was measured as log d. The sensitivity of response bias to reinforcement-ratio changes was independent of the value of the fixed duration, but was not independent of the discriminability of the variable durations from the fixed durations. Under current models, discriminability measures in complex temporal discrimination may be independent of biasing manipulations, but bias measures are not independent of stimulus values. 相似文献
54.
DOES EFFORT PLAY A ROLE IN THE EFFECT OF RESPONSE REQUIREMENTS ON DELAYED MATCHING TO SAMPLE? 总被引:2,自引:2,他引:0 下载免费PDF全文
The possible role of "effort" in the accuracy of pigeons' performance on a delayed matching-to-sample procedure was investigated by examining the effects of response requirements that accompanied a trial-initiating stimulus and that accompanied a sample stimulus. In the first experiment, the effect of varying the size of a fixed-ratio requirement for responses during an initiating stimulus was compared to that of varying a similar requirement for responses during the sample stimulus. Accuracy increased reliably with increases in the ratio scheduled during the sample stimulus, but was not significantly affected by increases in the ratio scheduled on the key during the initiating stimulus. In another phase of Experiment 1, sample duration was held constant while the ratio requirement was varied during the initiating stimulus. Again, accuracy of matching to sample was not significantly affected by the size of the ratio scheduled during the initiating stimulus. Experiment 2 provided a systematic replication of these results in another group of pigeons and included a more detailed analysis of responding. These results support the view that increases in sample-response requirement facilitate accuracy of delayed matching by increasing the durations of exposure to the sample stimuli, and do not support a role of effort in the sample-response effect. In Experiment 3, the facilitative effect of responses on the sample but not of those on the initiating stimulus was replicated using a simultaneous matching-to-sample procedure. This finding provides further evidence against an interpretation of response-requirement effects that appeals to effort; the finding also suggests that sample exposure might affect initial discrimination of the sample rather than remembering the sample. 相似文献
55.
Ronaldo Iachan 《Journal of Vocational Behavior》1984,24(2):133-141
A measure of agreement for partially ordered data is suggested that makes use of the k categories with the highest ranks, the ranks of the remaining categories being disregarded. The proposed measure is applied to the Self-Directed Search in order to evaluate its agreement with occupational preference. Other forms of agreement in the Holland classification system can also be assessed by the proposed measure. Examples are congruence and husband-wife and counselor-client agreement. 相似文献
56.
André Vandierendonck 《Acta psychologica》1984,55(1):71-83
In the first experiment, subjects rated the similarity of a sample of pairs of random dot patterns generated from 3 prototypes consisting of either 4, 6, or 9 dots. The results of the experiment tended to confirm the structure imposed on the patterns by the construction method. In the second experiment, subjects learned to classify random patterns generated from 2 prototypes with either short or long interprototype distance and consisting of either 4, 6, or 9 dots in a traditional concept identification task. After acquisition, memory for old and new distortions and the prototype, which was not presented during learning, was assessed. The tendency to call a pattern “new” increased with the distance between the pattern and its prototype. In a subsequent transfer test, all subjects saw patterns of either 4, 6, or 9 dots. Performance was above chance and the transfer from larger to smaller patterns tended to be greater than the transfer from smaller to larger patterns. This is consistent with a process of schema formation based on features common to most exemplars of the category. The results are discussed in relation to several theories of concept learning and schema abstraction. 相似文献
57.
This study examined changes in cognitive-dissonance-related variables during the professional training period. Differences in levels and change in satisfaction with career choice, importance of career, certainty of career decision, self-occupational perceptions, general attitude toward career, time since career decision, and past experience were observed when students who left a collegiate professional training program before program completion were compared with those who remained in the program. Data supports the validity of D. Hershenson and R. Roth's (1966, Journal of Counseling Psychology, 13, 368–370) and V. Harren's (1979, Journal of Vocational Behavior, 14, 119–133) theoretical models of vocational decision and the Assessment of Career Decision Making scale. 相似文献
58.
Joan Daniels Pedro 《Journal of Vocational Behavior》1984,25(1):80-95
Some form of work experience or internship ranks high on the list of criteria used by recruiters of college graduates for positions as management trainees. While internships are discussed positively by students, faculty, and recruiters, their evaluation has been faulted as being highly subjective and lacking in the use of controls and psychometric sophistication. This study used an Institutional Cycle design to investigate changes occurring after participation in internships with three cohorts of college age students. Changes were noted in both terminal and instrumental values and in work-specific needs. In the former, changes moved the profiles of the students closer to those of campus recruiters. In the latter, changes moved the students' needs in the direction of characteristics of the job, away from environmental characteristics. 相似文献
59.
Susan D Phillips Nicholas J Pazienza Donna J Walsh 《Journal of Vocational Behavior》1984,25(1):96-105
This study provides a reexamination of the role of different decisional strategies in facilitating progress in occupational decision making. Although the assumptions that a rational decision making style is the preferred mode of vocational functioning has been endorsed in a variety of career theories and interventions, there has been conflicting evidence about the validity of this assumption. To examine the role of different decisional approaches in the progress of making an occupational decision, the rational, intuitive, and dependent decision making style scores of 71 undergraduate students were used to predict progress in occupational decision making. The results of the regression analyses failed to provide support for the assumption that a rational style is the most effective in accomplishing this careerrelated task, but indicated strong support for the conclusion that the use of dependent decisional strategies is damaging, particularly in early stages of the decisional process. 相似文献
60.
Three measures of chronic self-esteem, plus four measures developed to assess situational components of self-esteem (task-specific self-esteem and social self-esteem), were administered to 238 undergraduates at a large, urban university and a community college in the southeastern United States. Evidence for a composite construct of self-esteem was found. Results also indicate task-specific self-esteem correlates as high as .42 (p < .01) with chronic self-esteem and as high as .76 (p < .01) with social self-esteem. Task-specific self-esteem was found to be a better predictor of grade point average than chronic or social self-esteem. Suggestions are made for further research on the situational components of self-esteem to extend current findings. 相似文献