全文获取类型
收费全文 | 16417篇 |
免费 | 716篇 |
国内免费 | 7篇 |
出版年
2020年 | 182篇 |
2019年 | 186篇 |
2018年 | 290篇 |
2017年 | 269篇 |
2016年 | 300篇 |
2015年 | 219篇 |
2014年 | 274篇 |
2013年 | 1197篇 |
2012年 | 503篇 |
2011年 | 472篇 |
2010年 | 323篇 |
2009年 | 306篇 |
2008年 | 431篇 |
2007年 | 450篇 |
2006年 | 390篇 |
2005年 | 384篇 |
2004年 | 350篇 |
2003年 | 293篇 |
2002年 | 327篇 |
2001年 | 700篇 |
2000年 | 693篇 |
1999年 | 489篇 |
1998年 | 193篇 |
1997年 | 181篇 |
1996年 | 177篇 |
1995年 | 157篇 |
1994年 | 155篇 |
1992年 | 378篇 |
1991年 | 358篇 |
1990年 | 366篇 |
1989年 | 310篇 |
1988年 | 296篇 |
1987年 | 291篇 |
1986年 | 264篇 |
1985年 | 268篇 |
1984年 | 250篇 |
1983年 | 209篇 |
1982年 | 163篇 |
1979年 | 223篇 |
1978年 | 181篇 |
1975年 | 199篇 |
1974年 | 244篇 |
1973年 | 237篇 |
1972年 | 191篇 |
1971年 | 183篇 |
1970年 | 155篇 |
1969年 | 181篇 |
1968年 | 220篇 |
1967年 | 198篇 |
1966年 | 164篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Across the lifespan and across populations, humans ‘overimitate’ causally unnecessary behaviors. Such irrelevant‐action imitation facilitates faithful cultural transmission, but its immediate benefits to the imitator are controversial. Over short time scales, irrelevant‐action imitation may bootstrap artifact exploration or interpersonal affiliation, and over longer time scales it may facilitate acquisition of either causal models or social conventions. To investigate these putative functions, we recruited community samples from two under‐studied populations: Yasawa, Fiji, and Huatasani, Peru. We use a two‐action puzzle box: first after a video demonstration, and again one month later. Treating age as a continuous variable, we reveal divergent developmental trajectories across sites. Yasawans (44 adults, M = 39.9 years, 23 women; 42 children, M = 9.8 years, 26 girls) resemble documented patterns, with irrelevant‐action imitation increasing across childhood and plateauing in adulthood. In contrast, Huatasaneños (48 adults, M = 37.6 years, 33 women; 47 children, M = 9.3 years, 13 girls) evince a parabolic trajectory: adults at the site show the lowest irrelevant‐action imitation of any demographic set in our sample. In addition, all age sets in both populations reduce their irrelevant actions at Time 2, but do not reduce their relevant‐action imitation or goal attainment. Taken together, and considering the local cultural contexts, our results suggest that irrelevant‐action imitation serves a short‐term function and is sensitive to the social context of the demonstration. 相似文献
992.
Playfulness is an individual differences variable at the trait-level. It describes the ability to experience or (re)frame everyday situations as stimulating, interesting, and/or entertaining. Playfulness in adolescents is understudied. We collected self-report data on four facets of playfulness (other-directed, lighthearted, intellectual, and whimsical) in two German-speaking samples of adolescents (N1 = 210, N2 = 270; age range 13–18 years). The facets correlated positively, but to varying degrees with life satisfaction (social life, self, friends) and intrinsic goals. There was no relationship with self-reported school grades and achievement goals (Sample 1). Playfulness in girls was associated with peer-nominated (classmates) bullying behaviors and victimization status (Sample 2). Overall, the findings show that playfulness has an impact on various domains of the life of adolescents. We discuss directions for further research in the field. 相似文献
993.
James Brielle T. Webster Mackenzie F. Menzel Charles R. Whitham Will Beran Michael J. 《Animal cognition》2020,23(5):861-869
Animal Cognition - Errors of source monitoring are widespread human memory challenges, and our memories are subject to distortion upon the presentation of subsequent misinformation. Less is known... 相似文献
994.
995.
Thirty-three twelve-month-old infants were divided into three groups based on the frequency and length of naturally-occurring nontraumatic separations from mother during the first year. One group had experienced only brief separations when left with a babysitter for an evening. A second group had been left once or twice for an average of five days while parents vacationed. A third group had been left regularly and frequently during the daytime, usually because mother was working. These groups were compared on measures of reaction to separation and reunion, in the home and in the laboratory, at one year of age. No group differences were found on any of the dependent variables. It is suggested that the quality of substitute care is probably more important than separation per se in mediating the impact of employment or daycare on infant development. 相似文献
996.
A model was presented describing the reciprocal influence of disruptions in parent discipline practices on irritable exchanges between the target child and other family members. Disrupted parent discipline and irritable microsocial exchanges within the family were hypothesized to provide a basic training for aggression that generalizes to other settings such that the child is identified by peers, teachers, and parents as physically aggressive. Physical fighting was thought to lead to rejection by the normal peer group, which was hypothesized to feed back to further exacerbate fighting. Multilevel assessment including interview, questionnaires, laboratory studies, and home observations were carried out with the families of 91 preadolescent and adolescent boys. Nine indicators from the assessment battery were used to define the constructs Inept Parental Discipline, Negative Microsocial Exchanges, Physical Fighting, and Poor Peer Relations. Structural equations (LISREL VI) were used to describe the relations among the constructs. The t values for the path coefficients were significant. A chi-square analysis showed an acceptable fit between the model and the empirical findings. The findings were interpreted as being consistent with the hypothesis that under certain circumstances, family interaction may serve as basic training for aggression. In the present study, interactions with siblings in the home seemed to serve a pivotal role. 相似文献
997.
998.
999.
1000.