全文获取类型
收费全文 | 38512篇 |
免费 | 1625篇 |
国内免费 | 26篇 |
出版年
2020年 | 428篇 |
2019年 | 549篇 |
2018年 | 741篇 |
2017年 | 745篇 |
2016年 | 847篇 |
2015年 | 571篇 |
2014年 | 708篇 |
2013年 | 3236篇 |
2012年 | 1269篇 |
2011年 | 1276篇 |
2010年 | 788篇 |
2009年 | 853篇 |
2008年 | 1116篇 |
2007年 | 1112篇 |
2006年 | 998篇 |
2005年 | 886篇 |
2004年 | 882篇 |
2003年 | 798篇 |
2002年 | 876篇 |
2001年 | 1144篇 |
2000年 | 1136篇 |
1999年 | 886篇 |
1998年 | 443篇 |
1997年 | 410篇 |
1995年 | 421篇 |
1993年 | 384篇 |
1992年 | 721篇 |
1991年 | 672篇 |
1990年 | 639篇 |
1989年 | 616篇 |
1988年 | 597篇 |
1987年 | 537篇 |
1986年 | 543篇 |
1985年 | 608篇 |
1984年 | 523篇 |
1983年 | 507篇 |
1982年 | 410篇 |
1981年 | 385篇 |
1979年 | 581篇 |
1978年 | 437篇 |
1977年 | 411篇 |
1976年 | 406篇 |
1975年 | 454篇 |
1974年 | 531篇 |
1973年 | 521篇 |
1972年 | 455篇 |
1971年 | 383篇 |
1968年 | 455篇 |
1967年 | 404篇 |
1966年 | 388篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
John Y. H. Bai Sarah Cowie Anne C. Macaskill Douglas Elliffe Christopher A. Podlesnik 《Journal of the experimental analysis of behavior》2020,113(2):363-389
It is widely assumed that reinforcers are biologically relevant stimuli, or stimuli that have been associated with biologically relevant stimuli. However, brief, arbitrary stimuli have also been reported to have reinforcement-like effects, despite being unrelated to biologically relevant stimuli like food. The present study explored the potential reinforcement-like effects of brief stimuli across 5 experiments. In Experiments 1 through 4, pigeon subjects responded for food reinforcement and brief stimulus presentations in a 2-component multiple schedule. Neither baseline response rates nor resistance to change during disruption tests were systematically greater in a component with versus without brief stimulus presentations. Increasing the rate and duration of brief stimulus presentations in Experiment 4 did not reveal reinforcement-like effects when compared directly with food. In Experiment 5, pigeons chose between independent terminal links in a concurrent-chains procedure. Across conditions, varying the location, duration, and rate of brief stimulus presentations in the terminal links had no systematic effects on preference. In contrast, varying rates of food reinforcers resulted in large and reliable shifts in preference. Therefore, the present study found no systematic evidence that brief stimuli unrelated to food reliably increase response rates, resistance to change, or preference. These data demonstrate the value of systematic replication, and a behavioral momentum approach to assessing potential reinforcement-like effects. 相似文献
22.
23.
24.
Intention is theorized as the proximal determinant of behavior in some theories of motivation, but the need to understand predictors of action control (i.e., translating an intention into behavior) is warranted to tailor physical activity intervention efforts. The purpose of this study was to examine constructs of the transtheoretical model of behavior change (TTM) as predictors of physical activity intention-behavior profiles across 6 months in a large Canadian sample (N = 1,192). Results showed that 5 of the 8 possible intention-behavior profiles had a substantial number of participants: nonintenders, unsuccessful adopters, successful adopters, unsuccessful maintainers, and successful maintainers. Constructs of the TTM distinguished (p < .01) intention-behavior profiles. Self-efficacy and the behavioral processes of change were particularly good predictors of action control (p < .01), but disaggregated beliefs and processes identified specific intervention targets for successful physical activity adoption and maintenance. The results validate that both action planning and action control are important when understanding physical activity behavior. 相似文献
25.
Abby C King Bess Marcus David Ahn Andrea L Dunn W Jack Rejeski James F Sallis Mace Coday 《Health psychology》2006,25(3):336-347
The authors used recursive partitioning methods to identify combinations of baseline characteristics that predict 2-year physical activity success in each of 3 physical activity interventions delivered in the multisite Activity Counseling Trial. The sample consisted of 874 initially sedentary primary care patients, ages 35-75 years, who were at risk for cardiovascular disease. Predictors of 2-year success were specific to each intervention and represented a range of domains, including physiological, demographic, psychosocial, health-related, and environmental variables. The results indicate how specific patient subgroups (e.g., obese, unfit individuals; high-income individuals in stable health) may respond differently to varying levels and amounts of professional assistance and support. The methods used provide a practical first step toward identifying clinically meaningful patient subgroups for further systematic investigation. 相似文献
26.
One possible explanation for the association between Cook-Medley Hostility Scale (Ho Scale; W. W. Cook & D. M. Medley, 1954) scores and premature coronary artery disease (CAD) morbidity and mortality is that hostile persons also have elevations on CAD risk factors. Meta-analyses with fixed and random-effects models were used to evaluate the relationship between Ho Scale scores and CAD risk factors in the empirical literature. Ho Scale scores were significantly related to body mass index, waist-to-hip ratio, insulin resistance, lipid ratio, triglycerides, glucose, socioeconomic status (SES), alcohol consumption, and smoking. Although there was also heterogeneity among study outcomes, the results of conservative random effects models provide confidence in the obtained relationships. On the basis of available evidence, researchers might give attention to obesity, insulin resistance, damaging health behaviors, and SES as potential contributing factors in understanding the association between Ho Scale scores and CAD. 相似文献
27.
This study examined the role of illness uncertainty in pain coping among women with fibromyalgia (FM), a chronic pain condition of unknown origin. Fifty-one FM participants completed initial demographic and illness uncertainty questionnaires and underwent 10-12 weekly interviews regarding pain, coping difficulty, and coping efficacy. Main outcome measures included weekly levels of difficulty coping with FM symptoms and coping efficacy. Multilevel analyses indicated that pain elevations for those high in illness uncertainty predicted increases in coping difficulty. Furthermore, when participants had more difficulty coping, they reported lower levels of coping efficacy. Results were consistent with hypothesized effects. Illness uncertainty accompanied by episodic pain negatively influenced coping efficacy, an important resource in adaptation to FM. 相似文献
28.
Human communication is thoroughly context bound. We present two experiments investigating the importance of the shared context, that is, the amount of knowledge two interlocutors have in common, for the successful emergence and use of novel conventions. Using a referential communication task where black‐and‐white pictorial symbols are used to convey colors, pairs of participants build shared conventions peculiar to their dyad without experimenter feedback, relying purely on ostensive‐inferential communication. Both experiments demonstrate that access to the visual context promotes more successful communication. Importantly, success improves cumulatively, supporting the view that pairs establish conventional ways of using the symbols to communicate. Furthermore, Experiment 2 suggests that dyads with access to the visual context successfully adapt the conventions built for one color space to another color space, unlike dyads lacking it. In linking experimental pragmatics with language evolution, the study illustrates the benefits of exploring the emergence of linguistic conventions using an ostensive‐inferential model of communication. 相似文献
29.
30.
In this paper, we organize past and present theories and models of creativity by using a new conceptual framework—the creativity matrix—with the aim of highlighting the dimensions of creativity we know a lot about and those we tend to either ignore or find difficult to study. This matrix is formed by bringing together a developmental model of creativity (the 4 C's) and a structural one (the 5 A's). We start by briefly describing these two conceptual frameworks, and then, we proceed to exploring the matrix itself by describing how the 5 A's are dynamically organized at each “level” of the 4 C's. Importantly, our overview of the matrix is informed by existing models and concepts that address one of more of the C's and the A's. This gives us a unique opportunity to take stock of what has been studied so far and, toward the end, consider new avenues for the development of theory and research agendas within creativity studies. 相似文献