全文获取类型
收费全文 | 2697篇 |
免费 | 123篇 |
国内免费 | 1篇 |
专业分类
2821篇 |
出版年
2023年 | 17篇 |
2022年 | 15篇 |
2021年 | 29篇 |
2020年 | 43篇 |
2019年 | 52篇 |
2018年 | 73篇 |
2017年 | 79篇 |
2016年 | 111篇 |
2015年 | 56篇 |
2014年 | 86篇 |
2013年 | 318篇 |
2012年 | 140篇 |
2011年 | 143篇 |
2010年 | 88篇 |
2009年 | 78篇 |
2008年 | 130篇 |
2007年 | 112篇 |
2006年 | 107篇 |
2005年 | 85篇 |
2004年 | 97篇 |
2003年 | 90篇 |
2002年 | 62篇 |
2001年 | 60篇 |
2000年 | 53篇 |
1999年 | 38篇 |
1998年 | 34篇 |
1997年 | 36篇 |
1996年 | 33篇 |
1995年 | 39篇 |
1994年 | 26篇 |
1993年 | 31篇 |
1992年 | 32篇 |
1991年 | 27篇 |
1990年 | 32篇 |
1989年 | 18篇 |
1988年 | 30篇 |
1987年 | 17篇 |
1986年 | 14篇 |
1985年 | 21篇 |
1984年 | 21篇 |
1983年 | 16篇 |
1982年 | 23篇 |
1979年 | 20篇 |
1978年 | 12篇 |
1977年 | 16篇 |
1974年 | 18篇 |
1972年 | 13篇 |
1971年 | 11篇 |
1970年 | 11篇 |
1968年 | 12篇 |
排序方式: 共有2821条查询结果,搜索用时 15 毫秒
931.
The aim of the study is to examine whether the playing of driving games and the viewing of music videos during adolescence predict crash involvement in emerging adulthood. A prospective cohort study (N = 471) with a five-year interval was used to measure adolescents' gender, media use, personality characteristics (baseline measurement), and crash involvement (follow-up). At baseline measurement (2006), respondents were 17 or 18 years old and did not yet have their driver's license. Data were analyzed by means of logistic regression analyses and the calculation of attributable risks. Respondents who watched music videos at least several times a week (OR = 4.319) or respondents who played drive'em up games at least a few times a month (OR = 3.125) had a heightened chance of being involved in a car crash five years later, even after controlling for their total media exposure, gender, and personality characteristics. Implications for prevention are discussed. 相似文献
932.
Marieke E. Timmerman Eva Ceulemans Kim De Roover Karla Van Leeuwen 《Behavior research methods》2013,45(4):1011-1023
To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the existing related clustering methods, including deterministic, stochastic, and unsupervised learning approaches. To evaluate subspace K-means, we performed a comparative simulation study, in which we manipulated the overlap of subspaces, the between-cluster variance, and the error variance. The study shows that the subspace K-means algorithm is sensitive to local minima but that the problem can be reasonably dealt with by using partitions of various cluster procedures as a starting point for the algorithm. Subspace K-means performs very well in recovering the true clustering across all conditions considered and appears to be superior to its competitor methods: K-means, reduced K-means, factorial K-means, mixtures of factor analyzers (MFA), and MCLUST. The best competitor method, MFA, showed a performance similar to that of subspace K-means in easy conditions but deteriorated in more difficult ones. Using data from a study on parental behavior, we show that subspace K-means analysis provides a rich insight into the cluster characteristics, in terms of both the relative positions of the clusters (via the centroids) and the shape of the clusters (via the within-cluster residuals). 相似文献
933.
Giulio E. Lancioni Mark F. O'reilly Jan Van Dijk Mieke Klaase 《Cognitive behaviour therapy》2013,42(3):130-134
Abstract An environmental enrichment programme was used for two passive children who had visual and hearing impairments and profound intellectual disabilities. The enrichment items, selected through stimulus preference assessments, were accessible contingent on simple adaptive responses. Data showed that both children increased their adaptive responding (thus reducing their passivity) during the programme. Implications of the findings are discussed. 相似文献
934.
Low‐price guarantees as advertisement strategy and compensation policy: The more,the better? 下载免费PDF全文
Tessa Haesevoets Alain Van Hiel Emma Onraet Anne Joosten David De Cremer 《Journal of Consumer Behaviour》2017,16(5):389-402
Companies sometimes employ a “lowest price or more than the difference back” policy (i.e., a price‐beating guarantee). We investigated whether such a policy is more effective to attract and retain customers than when the exact price difference is promised (i.e., a price‐matching guarantee). The first study revealed that about 60% of the marketers and shop owners in our sample thought that beating price differences is a more effective strategy than matching price differences. However, the four subsequent studies challenged this assumption. Specifically, the advertisement as well as the provision of price‐beating refunds did not have an incremental positive effect on customers' general attitudes in terms of trust, brand perception, loyalty, and shopping intentions beyond the level that was already reached by price‐matching refunds. Moreover, our mediation analyses revealed that the null effect of price‐matching versus price‐beating was mediated by fairness perceptions. From a theoretical perspective, these results are in line with a fairness account, which holds that people do not only evaluate the economic value of an outcome, but also take equality considerations into account. Because price‐beating is literally more expensive than price‐matching, from a practical point of view, companies should be informed that the employment of a price‐beating guarantee is a cost‐ineffective advertisement strategy and compensation policy. 相似文献
935.
Hieu Van Ngo Avery Calhoun Catherine Worthington Tim Pyrch David Este 《Journal of International Migration and Integration》2017,18(1):63-84
Grounded in the experiences of 30 gang-involved respondents in Calgary, this Canadian study examined criminal gang involvement of youth from immigrant families. Our analysis showed that gang-involved youth had experienced multiple, severe and prolonged personal and interpersonal challenges in all facets of their lives and that gradual disintegration of their relationships with family, school and community had resulted in the unravelling of self-concept, ethnic identity, sense of belonging and sense of citizenship and progressively propelled them towards membership in high-risk social cliques and criminal gangs. Our findings brought attention to the need for coordinated, comprehensive support for youth from immigrant families through family-based, school-based and community-based programs. 相似文献
936.
Lonneke Van Leeuwen Bas Van Den Putte Reint Jan Renes Cees Leeuwis 《Media Psychology》2017,20(2):194-220
Previous research suggests that narrative engagement (NE) in entertainment-education (E-E) narratives reduces counterarguing, thereby leading to E-E impact on behavior. It is, however, unclear how different NE processes (narrative understanding, attentional focus, emotional engagement, narrative presence) relate to different thought types (negative or positive; about the narrative form or about the target behavior) and to E-E impact. This study explores these relations in the context of alcohol binge drinking (BD). Participants (N = 172) watched an E-E narrative showing negative BD consequences, thereby aiming to discourage BD. The main findings were that the E-E narrative had a positive impact on discouraging BD on almost all assessed BD determinants such as beliefs and attitude. It was shown that attentional focus, emotional engagement, and narrative presence were associated with BD-discouraging impact, albeit on different BD-related determinants. No evidence was found that negative thoughts about BD mediated these associations. From this, we conclude that attentional focus, emotional engagement, and narrative presence were important for E-E impact but that negative thoughts about BD did not play a role therein. The study’s empirical and practical implications are discussed. 相似文献
937.
This study assesses the identity management strategies employed by gays, lesbians, and bisexuals in the U.S. military prior to and after the repeal of “Don’t Ask, Don’t Tell.” In-depth interviews were conducted with gay, lesbian, and bisexual service members and veterans. Data were analyzed using constant comparative analysis. Findings revealed that these service members made thoughtful and deliberate decisions about whether or not, and to whom, they would reveal their sexual identities. Identity concealment was practiced most often, even after the repeal, which was found to incite feelings of self-reproach, isolation, and stress. However, several new identity management strategies emerged after the repeal of “Don’t Ask, Don’t Tell” (i.e., strategies of openness) that stimulated positive self-feelings. By engaging in some level of openness, participants in this study were able to overcome some of the adverse effects of their minority stress. 相似文献
938.
Devon A. Grant Kimberly A. Honn Matthew E. Layton Samantha M. Riedy Hans P. A. Van Dongen 《Behavior research methods》2017,49(3):1020-1029
The psychomotor vigilance test (PVT) is widely used to measure reduced alertness due to sleep loss. Here, two newly developed, 3-min versions of the psychomotor vigilance test, one smartphone-based and the other tablet-based, were validated against a conventional 10-min laptop-based PVT. Sixteen healthy participants (ages 22–40; seven males, nine females) completed a laboratory study, which included a practice and a baseline day, a 38-h total sleep deprivation (TSD) period, and a recovery day, during which they performed the three different versions of the PVT every 3 h. For each version of the PVT, the number of lapses, mean response time (RT), and number of false starts showed statistically significant changes across the sleep deprivation and recovery days. The number of lapses on the laptop was significantly correlated with the numbers of lapses on the smartphone and tablet. The mean RTs were generally faster on the smartphone and tablet than on the laptop. All three versions of the PVT exhibited a time-on-task effect in RTs, modulated by time awake and time of day. False starts were relatively rare on all three PVTs. For the number of lapses, the effect sizes across 38 h of TSD were large for the laptop PVT and medium for the smartphone and tablet PVTs. These results indicate that the 3-min smartphone and tablet PVTs are valid instruments for measuring reduced alertness due to sleep deprivation and restored alertness following recovery sleep. The results also indicate that the loss of sensitivity on the 3-min PVTs may be mitigated by modifying the threshold defining lapses. 相似文献
939.
940.
Brett Van Leer-Greenberg 《The Journal of medical humanities》2017,38(2):147-149
The Five Senses of Haiti discusses a series of medical mission trips by physicians and medical students to the Central Plateau of Haiti delivering care in the outpatient setting. Practitioners describe their experiences through the use of their five senses to draw contrast between modern health care and medical practice in the developing world. Physicians in a resource poor setting are left without the usual diagnostic armamentarium and the safeguards and distractions of the modern hospital setting. This deficit creates an opportunity to devote time and focus to individual patients. Practicing medicine in this context clinicians use a heightened sense of awareness and increase their reliance on physical exam findings. Global medicine creates an opportunity for medical students to learn and physicians out of training to practice overlooked physical exam skills in the modern era. Physical exam findings and patient care yield diagnoses and fosters the bonds of the doctor-patient relationship. 相似文献