全文获取类型
收费全文 | 19157篇 |
免费 | 1587篇 |
国内免费 | 1271篇 |
出版年
2024年 | 47篇 |
2023年 | 305篇 |
2022年 | 313篇 |
2021年 | 343篇 |
2020年 | 668篇 |
2019年 | 703篇 |
2018年 | 657篇 |
2017年 | 768篇 |
2016年 | 760篇 |
2015年 | 505篇 |
2014年 | 688篇 |
2013年 | 2089篇 |
2012年 | 438篇 |
2011年 | 563篇 |
2010年 | 478篇 |
2009年 | 668篇 |
2008年 | 857篇 |
2007年 | 941篇 |
2006年 | 885篇 |
2005年 | 756篇 |
2004年 | 659篇 |
2003年 | 540篇 |
2002年 | 486篇 |
2001年 | 310篇 |
2000年 | 292篇 |
1999年 | 241篇 |
1998年 | 190篇 |
1997年 | 163篇 |
1996年 | 138篇 |
1995年 | 117篇 |
1994年 | 107篇 |
1993年 | 95篇 |
1992年 | 67篇 |
1991年 | 50篇 |
1990年 | 51篇 |
1989年 | 31篇 |
1988年 | 41篇 |
1985年 | 391篇 |
1984年 | 446篇 |
1983年 | 355篇 |
1982年 | 455篇 |
1981年 | 448篇 |
1980年 | 450篇 |
1979年 | 397篇 |
1978年 | 461篇 |
1977年 | 366篇 |
1976年 | 373篇 |
1975年 | 286篇 |
1974年 | 282篇 |
1973年 | 244篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
291.
William A. Rottschaefer 《Zygon》1995,30(3):407-433
Abstract. B.F. Skinner allures us with the possibilities of turning the stones of materialistic rewards into the bread of human values. He tempts us by assuring success in achieving our goals through behavioral science, if only we give up our autonomy. He offers the power of complete control over our behaviors, on condition that we relinquish responsibility for our lives to a technological elite. Is B. F. Skinner a flesh-and-blood Grand Inquisitor? This essay tries to persuade the reader that Skinner's offers are worth considering. 相似文献
292.
Following the publication of an unknown letter of Jung's on the theme of the possibility of liberal dictatorship, the authors have presented the actual letter that prompted Jung's reply and a further letter from the 16–year-old boy in Kansas. An interview with Jung in Hearst's International Cosmopolitan Magazine conducted by H.R. Knickerbocker in 1938 initially prompted the boy to write to Jung and the interview, which has been published, is summarized. Economic and financial themes were prominent in the boy's mind and links are made to earlier discussions in this Journal about these matters. 相似文献
293.
Effects of a variable-ratio conditioning history on sensitivity to fixed-interval contingencies in rats. 总被引:7,自引:7,他引:0
下载免费PDF全文
![点击此处可从《Journal of the experimental analysis of behavior》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We investigated the possibility that human-like fixed-interval performances would appear in rats given a variable-ratio history (Wanchisen, Tatham, & Mooney, 1989). Nine rats were trained under single or compound variable-ratio schedules and then under a fixed-interval 30-s schedule. The histories produced high fixed-interval rates that declined slowly over 90 sessions; differences as a function of the particular history were absent. Nine control animals given only fixed-interval training responded at lower levels initially, but rates increased with training. Despite differences in absolute rates, rates within the intervals and postreinforcement pauses indicated equivalent development of the accelerated response patterns suggestive of sensitivity to fixed-interval contingencies. The finding that the histories elevated rates without retarding development of differentiated patterns suggests that the effective response unit was a burst of several lever presses and that the fixed-interval contingencies acted on these units in the same way as for single responses. Regardless of history, the rats did not manifest the persistent, undifferentiated responding reported for humans under comparable schedules. We concluded that the shortcomings of animal models of human fixed-interval performances cannot be easily remedied by including a variable-ratio conditioning history within the model. 相似文献
294.
A transformation of self-discrimination response functions in accordance with the arbitrarily applicable relations of sameness, more than, and less than 总被引:10,自引:9,他引:1
下载免费PDF全文
![点击此处可从《Journal of the experimental analysis of behavior》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In Experiment 1, 2 experimental subjects were given pretraining of nonarbitrary relations that brought their responses under the control of four contextual stimuli; same, opposite, more than, and less than. One control subject was not exposed to this pretraining. The 2 pretrained subjects and the 3rd nonpretrained subject then received training in six arbitrary relations, the following four relations being the most critical: same/A1-B1, same/A1-C1, less than/A1-B2, more than/A1-C2. All 3 subjects were then tested for seven derived relations, the following three relations being the most important: same/B1-C1, more than/B1-C2, less than/B1-B2. The 2 pretrained subjects, but not the nonpretrained subject, showed the derived relations. One of the stimuli (B1) from the relational network and two novel stimuli (X1 and X2) were then used to train three different self-discrimination responses on three complex schedules of reinforcement. That is, all 3 subjects were trained to pick X1 if they had not emitted a response, to pick B1 if they had emitted one response only, and to pick X2 if they had emitted two responses only. The 2 pretrained subjects, but not the nonpretrained subject, showed the predicted transformation of self-discrimination response functions in accordance with the relations of sameness, more than, and less than (i.e., no response, pick B2; one response only, pick C1; and two responses only, pick C2). In Experiment 2, 2 new subjects were employed, and the arbitrary relational training and testing phases were modified to control for a procedural artifact that may have contributed to the results of the first experiment. Experiment 2 replicated the findings of Experiment 1. The pattern of results support the utility of a relational frames approach to understanding derived stimulus relations. 相似文献
295.
In the behavioral theory of timing, pacemaker rate is determined by overall rate of reinforcement. A two-alternative free-operant psychophysical procedure was employed to investigate whether pacemaker period was also sensitive to the differential rate of reinforcement. Responding on a left key during the first 25 s and on a right key during the second 25 s of a 50-s trial was reinforced at variable intervals, and variable-interval schedule values during the two halves of the trials were varied systematically. Responding on the right key during the first 25 s and on the left key during the second 25 s was not reinforced. Estimates of pacemaker period were derived from fits of a function predicted by the behavioral theory of timing to right-key response proportions in consecutive 5-s bins of the 50-s trial. Estimates of pacemaker period were shortest when the differential reinforcer rate most strongly favored right-key responses, and were longest when the differential reinforcer rate most strongly favored left-key responses. The results were consistent with the conclusion that pacemaker rate is influenced by relative reinforcer rate. 相似文献
296.
Gerhard H. Fischer 《Psychometrika》1995,60(4):459-487
The paper addresses three neglected questions from IRT. In section 1, the properties of the “measurement” of ability or trait parameters and item difficulty parameters in the Rasch model are discussed. It is shown that the solution to this problem is rather complex and depends both on general assumptions about properties of the item response functions and on assumptions about the available item universe. Section 2 deals with the measurement of individual change or “modifiability” based on a Rasch test. A conditional likelihood approach is presented that yields (a) an ML estimator of modifiability for given item parameters, (b) allows one to test hypotheses about change by means of a Clopper-Pearson confidence interval for the modifiability parameter, or (c) to estimate modifiability jointly with the item parameters. Uniqueness results for all three methods are also presented. In section 3, the Mantel-Haenszel method for detecting DIF is discussed under a novel perspective: What is the most general framework within which the Mantel-Haenszel method correctly detects DIF of a studied item? The answer is that this is a 2PL model where, however, all discrimination parameters are known and the studied item has the same discrimination in both populations. Since these requirements would hardly be satisfied in practical applications, the case of constant discrimination parameters, that is, the Rasch model, is the only realistic framework. A simple Pearsonx 2 test for DIF of one studied item is proposed as an alternative to the Mantel-Haenszel test; moreover, this test is generalized to the case of two items simultaneously studied for DIF. 相似文献
297.
The literature is reviewed to define a sense of community in the workplace and to identify factors that may foster it. A model
is developed and estimated with survey data from a culturally diverse sample of men and women performing lower-level jobs
at a medium-sized manufacturing firm. Results of regression analyses are reported that correct for sample selection bias resulting
from the lower response rates of minority workers. Findings suggest that well-designed jobs and supportive workplace relationships
and policies are important in explaining workers' sense of community, defined as workers' perceptions of mutual commitment
between employee and employer. Informal sources of support play a larger role in explaining men's sense of community, while
formal sources of support are more important in explaining women's sense of community. Findings further suggest that African
American workers, especially women, have a difficult time experiencing a sense of community at work.
The authors thank the employees of Fel-Pro for their participation in this study and Melissa Roderick, Michael Sosin, and
anonymous reviewers for their thoughtful comments. This research was funded by the Fel-Pro/Mecklenberger Foundation and the
Lois and Samuel Silberman Fund. 相似文献
298.
Bruce A. Ryan Blaine Powel George F. Kawash Marshall Fine 《Journal of psychopathology and behavioral assessment》1995,17(3):283-291
Two parallel short forms of the Family of Origin Scale were developed from data provided by 69 women and 63 men who completed the full Family of Origin Scale along with a variety of measures of family-of-origin characteristics. Data on the reliability and validity of the short forms are provided and discussed. The results indicate that both short forms are strongly and significantly correlated with each other and with the full-scale version of the FOS and that they share its reliability and validity characteristics to a very high degree. 相似文献
299.
Thomas G. Haring Ph.D. 《Journal of Behavioral Education》1995,5(2):123-149
This paper presents a behavioral model which proposes that operants are organized and regulated into systems of responding. Multi-operant theory proposes that operants are organized into response systems that interact to adapt behavior to the complexities of the environment. The operant is the interaction between behavior and the environment which includes the conditions under which responses may occur, the class of behavior that is likely to be effective in producing outcomes, and the antecedent conditions that define the context of behavior. A central feature of this theory is that operants within a repertoire are organized into regulated systems of responding. The mechanisms of regulation are themselves operants that are learned and controlled by processes that are the same as those that govern more overt behavior. Operants stand in relationship to each other in coordinated response systems with some operants directly affecting and organizing the performance of other operants. An important implication of the systemic nature of behavioral repertoires is that bringing some aspect of a behavior class under control of new variables may demonstrate a spread throughout the entire operant system depending on past histories linking the classes.deceased 相似文献
300.
Caroline Whitbeck 《Science and engineering ethics》1995,1(4):322-328
She is guest editor for this special issue ofScience and Engineering Ethics on “Trustworthy Research”. 相似文献