全文获取类型
收费全文 | 719篇 |
免费 | 57篇 |
专业分类
776篇 |
出版年
2024年 | 4篇 |
2023年 | 12篇 |
2022年 | 9篇 |
2021年 | 28篇 |
2020年 | 29篇 |
2019年 | 37篇 |
2018年 | 48篇 |
2017年 | 48篇 |
2016年 | 40篇 |
2015年 | 32篇 |
2014年 | 26篇 |
2013年 | 88篇 |
2012年 | 57篇 |
2011年 | 71篇 |
2010年 | 34篇 |
2009年 | 21篇 |
2008年 | 36篇 |
2007年 | 36篇 |
2006年 | 17篇 |
2005年 | 25篇 |
2004年 | 12篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1963年 | 2篇 |
1960年 | 1篇 |
1958年 | 2篇 |
1955年 | 2篇 |
排序方式: 共有776条查询结果,搜索用时 9 毫秒
141.
142.
143.
Paul E. Johnson Alica S. Durán Frank Hassebrock James Moller Michael Prietula Paul J. Feltovich David B. Swanson 《Cognitive Science》1981,5(3):235-283
An investigation is presented in which a computer simulation model (DIAGNOSER) is used to develop and test predictions for behavior of subjects in a task of medical diagnosis. The first experiment employed a process-tracing methodology in order to compare hypothesis generation and evaluation behavior of DIAGNOSER with individuals at different levels of expertise (students, trainees, experts). A second experiment performed with only DIAGNOSER identified conditions under which errors in reasoning in the first experiment could be related to interpretation of specific data items. Predictions derived from DIAGNOSER's performance were tested in a third experiment with a new sample of subjects. Data from the three experiments indicated that (1) form of diagnostic reasoning was similar for all subjects trained in medicine and for the simulation model, (2) substance of diagnostic reasoning employed by the simulation model was parable with that of the more expert subjects, and (3) errors in subjects' reasoning were attributable to deficiencies in disease knowledge and the interpretation of specific patient data cues predicted by the simulation model. 相似文献
144.
Punishment of an alternative behavior generates resurgence of a previously extinguished target behavior 下载免费PDF全文
Rafaela M. Fontes João C. Todorov Timothy A. Shahan 《Journal of the experimental analysis of behavior》2018,110(2):171-184
Resurgence is often defined as the recurrence of an extinguished behavior when a more recently reinforced alternative behavior is also extinguished. Resurgence has also been observed when the alternative behavior is devalued by other means (e.g., reinforcement rate or magnitude reductions). The present study investigated whether punishment of an alternative behavior would generate resurgence. A target response was reinforced during Phase 1 and then extinguished in Phase 2 while an alternative response was reinforced. During Phase 3, response‐dependent foot shocks were superimposed on the schedule of reinforcement for the alternative response and shock intensity was escalated gradually across sessions. Resurgence of the target response was reliably observed, mostly at higher intensities. The effect was replicated in two subsequent exposures to the sequence of conditions, with resurgence tending to occur at the lowest foot shock intensity. These results suggest that devaluation of an alternative behavior via punishment can generate resurgence. Although it is difficult to reconcile the overall pattern of results with Bouton's context account, these findings are consistent with the suggestion that resurgence results from a “worsening of conditions” for the alternative behavior and with the formalization of that suggestion in terms of a choice‐based matching‐law account (i.e., Resurgence as Choice). 相似文献
145.
José-de-Jesús Lavalle-Martínez Manuel Montes-y-Gómez Luis Villaseñor-Pineda Héctor Jiménez-Salazar Ismael-Everardo Bárcenas-Patiño 《Studia Logica》2018,106(2):371-395
The concept of polarity is pervasive in natural language. It relates syntax, semantics and pragmatics narrowly (Giannakidou, in: Maienborn, von Heusinger, Portner (eds.), Semantics: an international handbook of natural language meaning, De Gruyter Mouton, Berlin, 2011; Israel in The grammar of polarity: pragmatics, sensitivity, and the logic of scales, Cambridge studies in linguistics, Cambridge University Press, Cambridge, 2014), it refers to items of many syntactic categories such as nouns, verbs and adverbs. Neutral polarity items appear in affirmative and negative sentences, negative polarity items cannot appear in affirmative sentences, and positive polarity items cannot appear in negative sentences. A way of reasoning in Natural Language is through Natural Logic (van Benthem in Essays in logical semantics, vol. 29 of Studies in linguistics and philosophy, Reidel, Dordrecht, 1986; Language in action: categories, lambdas, and dynamic logic, vol. 130 of Studies in logic, Elsevier, Amsterdam, 1991). This logic is based on the concept of polarity in order to make the meaning of a sentence weaker o stronger without changing its truth value. There exist many proposals to compute polarity in the Natural Logic context, the most widely known are the ones by: van Benthem (1986, 1991), Sánchez-Valencia (Studies on natural logic and categorial grammar, Ph.D. thesis, Universiteit van Amsterdam, 1991), Dowty (Proceedings of the 4th conference on semantics and theoretical linguistics, Cornel University, CLC Publications, Rochester, 1994), and van Eijck (in: ten Cate, Zeevat (eds.), 6th international Tbilisi symposium on logic, language, and computation, Batumi, Georgia, Springer, 2007). If Natural Logic is going to be used, as an inferential mechanism between text fragments, in Natural Language Processing applications such as text summarization, question answering, and information extraction, it is a priority to know what the existing relationship among the aforementioned algorithms is; for example, to implement the most general. We show in this paper the equivalence among the analyzed algorithms, filling a gap in Natural Logic research, particularly in computing polarity, and the soundness of their algorithms. 相似文献
146.
147.
Ana Maseda Laura Lorenzo-López Trinidad Lorenzo Clara Diego-Diez Begoña Alonso-Búa Rocío López-López José C. Millán-Calenti 《Applied research in quality of life》2018,13(1):119-136
Frailty is a dynamic clinical syndrome considered as part of an age-associated continuum of severity, including pre-frailty as an intermediate frailty status with potential reversibility to robustness. The main purpose of this study was to analyse the relationship between the different domains of quality of life, functional dependence and depressive symptomatology in older adults diagnosed as pre-frail, before progression to frailty occurs. Logistic regression analyses were conducted to examine whether sex, age, level of education and scores in the Geriatric Depression Scale 15-item Short Form (GDS-SF) and the Instrumental Activities of Daily Living Lawton scale determine the worst score in the WHOQOL-BREF (World Health Organization Quality of Life) in older adults meeting one or two frailty phenotypic criteria. Depressive symptomatology (GDS-SF score) was the main determinant of poor quality of life in both groups, and in all areas of WHOQOL-BREF. Age was only associated with poor satisfaction with own health. Female sex and low educational level were linked to low physical QOL and poor self-rated health, respectively, but only in older adults meeting one frailty criterion. Association between functional status and WHOQOL-BREF scores was only found in the univariate analysis. These results underline the importance of identifying multiple aspects, but mainly the presence of depressive symptomatology, as risk factors for all dimensions of quality of life in the pre-frailty process, where interventions might be targeted to reduce the progression of pre-frailty and frailty in older adults. 相似文献
148.
Tânia Ferraro Leonor Pais João Manuel Moreira Nuno Rebelo Dos Santos 《Applied research in quality of life》2018,13(2):501-523
This article aimed to investigate the role of Decent Work as a predictor of different types of Work Motivation and to explore the possible role of Psychological Capital in mediating this relationship. The Decent Work Questionnaire, the Multidimensional Work Motivation Scale, and the Psychological Capital Questionnaire were administered to 3004 knowledge workers, in Portugal and Brazil. Results from Structural Equation Modeling analyses support the hypothesized model, showing the predictor role of Decent Work and complete and partial mediation effects of PsyCap in different relationships between DW and Work motivation variables. The results also support the idea that a decent work context predicts more autonomous work motivations again with the mediation of PsyCap. In sum, the results suggest that decent work plays an important role in promoting a positive approach to work, and that Psychological Capital is an important mediating variable in the promotion of autonomous Work motivation. Limitations and practical implications conclude the article. 相似文献
149.
Guerra GP Mello CF Bochi GV Pazini AM Fachinetto R Dutra RC Calixto JB Ferreira J Rubin MA 《Neurobiology of learning and memory》2011,96(2):324-332
Spermidine (SPD) is an endogenous polyamine that modulates N-methyl-D-aspartate (NMDA) receptor function, and has been reported to facilitate memory formation. In the current study we determined whether or not the PKA/CREB signaling pathway is involved in SPD-induced facilitation of memory of inhibitory avoidance task in adult rats. The post-training administration of the cAMP-dependent protein kinase (PKA) inhibitor, N-[2-bromocinnamylamino)ethyl]-5-isoquinoline sulfonamide [H-89, 0.5 ρmol intrahippocampal (ih)] or the antagonist of the NMDA receptor polyamine-binding site (arcaine, 0.02 nmol ih) with SPD (0.2 nmol ih) prevented memory improvement induced by SPD. Intrahippocampal administration of SPD (0.2 nmol) facilitated PKA and cAMP response element-binding protein (CREB) phosphorylation in the hippocampus 180 min, but not 30 min, after administration, and increased translocation of the catalytic subunit of PKA into the nucleus. Arcaine (0.02 nmol) and H-89 (0.5 ρmol) prevented the stimulatory effect of SPD on PKA and CREB phosphorylation. These results suggest that memory enhancement induced by the ih administration of SPD involves the PKA/CREB pathways in rats. 相似文献
150.
Spain is one of the EU countries that receive most immigrants, especially from Latin America. The process of migration implies a high level of stress what may have repercussions for the mental health of immigrants. The purposes of this study were: (a) to determine whether the degree of mental health of immigrant women differs according to their rural or urban origin, (b) to compare the mental health of immigrant women with that of the female normative sample of host population (Spain). A sample of 186 Latin American immigrant women (142 from urban areas and 44 from rural areas) was recruited in Barcelona by means of a consecutive case method. A structured interview and the SCL-90-R were administered. The results indicated that the immigrant women from rural origin reported higher levels of psychological symptomatology than those from urban areas. Immigrants reported higher levels of psychological symptomatology than the native female population and in most of the psychological symptoms exceeded 90% of the native Spanish population. Migration is a powerful stressor which may lead to psychological distress. Being female of rural origin and being in an illegal situation is related with an increase in symptomatology. 相似文献