全文获取类型
收费全文 | 17724篇 |
免费 | 1765篇 |
国内免费 | 1114篇 |
出版年
2023年 | 234篇 |
2022年 | 200篇 |
2021年 | 316篇 |
2020年 | 571篇 |
2019年 | 660篇 |
2018年 | 604篇 |
2017年 | 729篇 |
2016年 | 725篇 |
2015年 | 456篇 |
2014年 | 581篇 |
2013年 | 1921篇 |
2012年 | 390篇 |
2011年 | 489篇 |
2010年 | 412篇 |
2009年 | 612篇 |
2008年 | 769篇 |
2007年 | 827篇 |
2006年 | 782篇 |
2005年 | 665篇 |
2004年 | 585篇 |
2003年 | 478篇 |
2002年 | 460篇 |
2001年 | 296篇 |
2000年 | 278篇 |
1999年 | 242篇 |
1998年 | 205篇 |
1997年 | 163篇 |
1996年 | 152篇 |
1995年 | 136篇 |
1994年 | 125篇 |
1993年 | 109篇 |
1992年 | 86篇 |
1991年 | 66篇 |
1990年 | 66篇 |
1989年 | 49篇 |
1988年 | 56篇 |
1987年 | 51篇 |
1985年 | 389篇 |
1984年 | 433篇 |
1983年 | 363篇 |
1982年 | 470篇 |
1981年 | 458篇 |
1980年 | 464篇 |
1979年 | 417篇 |
1978年 | 458篇 |
1977年 | 372篇 |
1976年 | 378篇 |
1975年 | 279篇 |
1974年 | 278篇 |
1973年 | 236篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Rolf Loeber Ph.D. Stephanie M. Green M.A. Benjamin B. Lahey Ph.D. Mary Anne G. Christ M.A. Paul J. Frick Ph.D. 《Journal of child and family studies》1992,1(1):21-41
Retrospective and prospective reports of the onset of disruptive child behaviors were analyzed in a sample of clinic-referred boys. The younger boys (ages 7–9 years), compared with the older boys (ages 10–12 years), showed the highest level of disruptive behavior and, judging from mothers' reports, had the fastest progression of onsets from less serious to more serious problem behaviors. Despite some overlap, developmental sequences in problem behavior within the domains of hyperactivity/inattention, oppositional behavior, and conduct problems were similar across the two age groups. This was also the case for developmental sequences of overt or confrontive problem behaviors and covert or concealing conduct problems. Sequences of the onset of oppositional behavior and conduct problems were validated through prospective data, based on the information from mothers, teachers, and boys themselves. The implications of the findings are discussed for the formulation of developmental pathways of behavior and the analysis of causal factors. 相似文献
42.
A new method for determining the minimum number of observations per subject needed to achieve a specific generalizability coefficient is presented. This method, which consists of a branch-and-bound algorithm, allows for the employment of constraints specified by the investigator. 相似文献
43.
Paul R. Rosenbaum 《Psychometrika》1989,54(4):625-633
Established results on latent variable models are applied to the study of the validity of a psychological test. When the test predicts a criterion by measuring a unidimensional latent construct, not only must the total score predict the criterion, but the joint distribution of criterion scores and item responses must exhibit a certain pattern. The presence of this population pattern may be tested with sample data using the stratified Wilcoxon rank sum test. Often, criterion information is available only for selected examinees, for instance, those who are admitted or hired. Three cases are discussed: (i) selection at random, (ii) selection based on the current test, and (iii) selection based on other measures of the latent construct. Discriminant validity is also discussed.This work was supported in part by Grant SES-87-01890 from the Measurement Methods and Data Improvement Program of the U.S. National Science Foundation. 相似文献
44.
We propose a method for detecting influential observations in iterative principal factor analysis. For this purpose we derive the influence functionsI(x; LL
T
) andI(x; ) for the common variance matrixT =LL
T
and the unique variance matrix , respectively, in the common factor decomposition =LL
T
+ . A numerical example is given for illustration.The authors are grateful to Tomoyuki Tarumi and Atsuhiro Hayashi for their kind permission to use their software Seto/B for drawing Figures 1 and 2 and to anonymous reviewers for comments on the paper. 相似文献
45.
Bengt O. Muthén 《Psychometrika》1989,54(3):385-396
The problem of detecting instructional sensitivity (item basis) in test items is considered. An illustration is given which shows that for tests with many biased items, traditional item bias detection schemes give a very poor assessment of bias. A new method is proposed instead. This method extends item response theory (IRT) by including item-specific auxiliary measurement information related to opportunity-to-learn. Item-specific variation in measurement relations across students with varying opportunity-to-learn is allowed for.This paper was presented at the 1987 AERA meeting in Washington, DC. This research was supported by grant OERI-G-86-003 from the Office of Educational Research and Improvement, Department of Education. The author thanks Michael Hollis and Chih-fen Kao for valuable research assistance, and appreciates valuable comments made by an anonymous reviewer. 相似文献
46.
Social anxiety and fear of bodily sensations in panic disorder and agoraphobia: A matched comparison
Corine de Ruiter Bert Garssen 《Journal of psychopathology and behavioral assessment》1989,11(2):175-184
This study tests the hypothesis that social anxiety and fear of bodily sensations are associated with the development of agoraphobic avoidance behavior in panic disorder patients. Twenty patients with panic disorder were compared to 20 patients with panic disorder with agoraphobia, matched by sex and duration of disorder. The two groups did not differ on measures of fear and frequency of assertive social responses. However, the agoraphobics scored higher on measures of interpersonal sensitivity, depression, feelings of inadequacy, and hostility. They also reported higher fear of bodily sensations. Although definitive conclusions need to be postponed until prospective studies have been conducted, there is evidence suggesting that the development of agoraphobia in panic patients is associated with hypersensitivity to bodily sensations and interpersonal situations.This research was supported by Grant 560-268-009 of the Dutch Organization for Scientific Research. 相似文献
47.
Hwe Ik Zhang 《Zygon》1989,24(4):447-456
Abstract. The position and role of humanity in the world of life is examined in the light of the ontological structure of life itself. This problem is approached by considering the possible units of life representing various modes of life phenomena. I argue that the only meaningful unit of life without interposing some special external conditions is "global life" framed in a star-planet system. Any other possible unit of life exhibited by various kinds of individuals is conditional in the sense that it would leave out an essential part as "co-life." The relationship between human being and the global life should be understood in this general scheme of individual and global life. It is emphasized, however, that human being occupies a unique position in global life in the sense that humanity can promote either a cancerous situation or a healthy higher-order enhancement of the global life. 相似文献
48.
Philip Clayton 《Zygon》1989,24(3):315-334
Abstract. Imre Lakatos's philosophy of science can provide helpful leads for theological methodology, but only when mediated by the disciplines that lie between the natural sciences and theology. The questions of relativism and truth are used as indices for comparing disciplines, and Lakatos's theory of natural science is taken as the starting point. Major modifications of Lakatos's work are demanded as one moves from the natural sciences, through economics, the interpretive social sciences, literary theory, and into theology. Although theology may consist of Lakatosian research programs, it also includes programs of interpretation and programs for living. This conclusion must influence our definition of theological truth and our assessment of theological relativism. 相似文献
49.
Six pigeons were trained with a chain variable-interval variable-interval schedule on the left key and with reinforcers available on the right key on a single variable-interval schedule arranged concurrently with both links of the chain. All three schedules were separately and systematically varied over a wide range of mean intervals. During these manipulations, the obtained reinforcer rates on constant arranged schedules also frequently changed systematically. Increasing reinforcer rates in Link 2 of the chain increased response rates in both links and decreased response rates in the variable-interval schedule concurrently available with Link 2. Increasing Link-1 reinforcer rates increased Link-1 response rates and decreased Link-2 response rates. Increasing reinforcer rates on the right-key schedule decreased response rates in Link 1 of the chain but did not affect the rate in Link 2. The results extend and amplify previous analyses of chain-schedule performance and help define the effects that a quantitative model must describe. However, the complexity of the results, and the fact that constant arranged reinforcer schedules did not necessarily lead to constant obtained reinforcer rates, precluded a quantitative analysis. 相似文献
50.
Visually guided catching and tracking skills in pigeons: A preliminary analysis 总被引:2,自引:1,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)
Research on reaching, tracking, and catching in the pigeon has been hampered by limitations of technology. A new system was developed in which the target was a small rectangle presented on a video display terminal and the pecking response was detected with touch technology. The target moved up and down vertically with sinusoidal velocity. A coincidence between the location of the pigeon's beak and the cursor produced reinforcement. The pigeon pecked ahead and behind the target, but most pecks occurred behind the target so the dominant tracking strategy was lagging. The pigeon was adept at “catching” the target at many locations throughout the trajectory. Transfer of motor learning was tested on probe trials during which the trajectory changed from vertical to horizontal. On transfer trials the pigeons' dominant pattern of pecking immediately shifted from vertical to horizontal. The motor skill displayed by the pigeons was flexible and adaptive, suggesting that the pigeons had learned to track the cursor. 相似文献