首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   712篇
  免费   29篇
  2022年   5篇
  2021年   19篇
  2020年   10篇
  2019年   21篇
  2018年   20篇
  2017年   24篇
  2016年   16篇
  2015年   11篇
  2014年   13篇
  2013年   79篇
  2012年   24篇
  2011年   37篇
  2010年   18篇
  2009年   24篇
  2008年   27篇
  2007年   29篇
  2006年   24篇
  2005年   36篇
  2004年   19篇
  2003年   37篇
  2002年   31篇
  2001年   13篇
  2000年   15篇
  1999年   13篇
  1998年   13篇
  1997年   12篇
  1996年   11篇
  1995年   4篇
  1994年   9篇
  1993年   6篇
  1992年   10篇
  1991年   4篇
  1990年   8篇
  1989年   8篇
  1988年   4篇
  1987年   3篇
  1986年   5篇
  1985年   6篇
  1984年   8篇
  1983年   7篇
  1982年   6篇
  1981年   4篇
  1979年   4篇
  1978年   4篇
  1977年   3篇
  1975年   5篇
  1973年   3篇
  1970年   3篇
  1968年   7篇
  1967年   3篇
排序方式: 共有741条查询结果,搜索用时 203 毫秒
51.
In this paper, I introduce and examine the notion of “mathematical engineering” and its impact on mathematical change. Mathematical engineering is an important part of contemporary mathematics and it roughly consists of the “construction” and development of various machines, probes and instruments used in numerous mathematical fields. As an example of such constructions, I briefly present the basic steps and properties of homology theory. I then try to show that this aspect of contemporary mathematics has important consequences on our conception of mathematical knowledge, in particular mathematical growth.  相似文献   
52.
53.
54.
The author describes "higher" and "uniquely human" sociocognitive skills that he argues as being necessary for tool use. We propose that those skills could be based on simpler detection systems humans could share with other animal tool users. More specifically, we discuss the impact of object affordances on the understanding and the social learning of tool use.  相似文献   
55.
We describe an ontology of philosophy that is designed to aid navigation through philosophical literature, including literature in the form of encyclopedia articles and textbooks and in both printed and digital forms. The ontology is designed also to serve integration and structuring of data pertaining to the philosophical literature, and in the long term also to support reasoning about the provenance and contents of such literature, by providing a representation of the philosophical domain that is oriented around what philosophical literature is about.  相似文献   
56.
The present study examined age differences in the disposition to forgive others and the role of interpersonal transgression frequency and intensity. Data from a representative cross-sectional sample of Swiss adults (N = 451, age: 20–83 years) were used. Participants completed a self-report measure of forgivingness and indicated whether and how intense they have experienced different types of interpersonal transgressions during the past 12 months. Results indicate that older adults were, on average, more willing to forgive others than younger adults. Frequency and intensity of transgressions were negatively related with age. Moreover, the results show that transgression frequency and intensity explained, in part, age differences in forgivingness. Future directions concerning the meaning of age differences in forgivingness are discussed.  相似文献   
57.
This study assessed the validity of the Patient–Doctor Relationship Questionnaire-9 (PDRQ-9) in a primary care sample (N = 180). Convergent validity was assessed through a correlation between the patient-rated PDRQ-9 and the physician-rated Difficult Doctor Patient Relationship Questionnaire-10 (DDPRQ-10). Discriminant validity was assessed through correlations between the PDRQ-9 and patient age, patient- and physician-reported health and psychological distress. To determine if the PDRQ-9 could discriminate between groups, patient PDRQ-9 ratings were compared between patients who were treated by faculty physicians versus those who were treated by residents. An exploratory factor analysis confirmed that the PDRQ-9 was made up of a single factor. The PDRQ-9 scale was internally consistent (α = .96) and significantly and negatively correlated with the DDPRQ-10 (r = ?.22, p = .003) and was not significantly correlated with patient age, health, or psychological distress. PDRQ-9 ratings were statistically greater in patients who were treated by faculty physicians than those who were treated by residents (p = .01). This study provides additional support for the reliability and validity of the PDRQ-9 as a measure of the doctor–patient relationship in a primary care sample.  相似文献   
58.
Motivation and Emotion - Mourning constitutes an important human emotion, which might cause—among other things—major depressive symptoms when lasting for too long. To date, no study...  相似文献   
59.

Objective

To describe an immobility reaction (IR) that was not previously reported at or immediately after birth in human newborns.

Method

We analyzed 31 videos of normal term vaginal deliveries recorded from Time 0 of birth defined as the as the moment that lies between the birth of the thorax and the pelvis of the infant. We searched for perinatal factors associated with newborn's IR.

Results

IR at birth was observed in 8 of the 31 newborns. The main features of their behavior were immobilization, frozen face, shallow breathing and bradycardia. One of the 8 newborns had sudden collapse 2 h after birth. We found significant relationships between maternal prenatal stress (PS) and IR (p = .037), and a close to significant one between infants’ lividness at Time 0 and IR (p = .053). The first breath of the 31 newborns occurred before and was not associated with the first cry (p < .001).

Discussion

The main features of IR at birth are similar to those of the universal most severe response to severe stress or danger. The relationship with PS suggests that children who had IR at birth might be at risk for similar disorders as those associated with PS. Sudden neonatal collapse of one of the IR newborns needs further research to determine if they are at risk for sudden infant death syndrome.

Conclusion

This first report of an IR reaction at birth in human infants could open up new paths for improving early neonatal care. Further research is needed for maternal PS, stress hormones, umbilical cord blood pH measurements in IR newborns. The challenge of education and support for parents of IR newborns is outlined.  相似文献   
60.
To harness the complexity of their high‐dimensional bodies during sensorimotor development, infants are guided by patterns of freezing and freeing of degrees of freedom. For instance, when learning to reach, infants free the degrees of freedom in their arm proximodistally, that is, from joints that are closer to the body to those that are more distant. Here, we formulate and study computationally the hypothesis that such patterns can emerge spontaneously as the result of a family of stochastic optimization processes, without an innate encoding of a maturational schedule. In particular, we present simulated experiments with an arm where a computational learner progressively acquires reaching skills through adaptive exploration, and we show that a proximodistal organization appears spontaneously, which we denote PDFF (Proximo Distal Freezing and Freeing of degrees of freedom). We also compare this emergent organization between different arm morphologies—from human‐like to quite unnatural ones—to study the effect of different kinematic structures on the emergence of PDFF.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号