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   1430篇
  免费   50篇
  2022年   5篇
  2020年   27篇
  2019年   24篇
  2018年   27篇
  2017年   32篇
  2016年   39篇
  2015年   36篇
  2014年   23篇
  2013年   177篇
  2012年   51篇
  2011年   62篇
  2010年   28篇
  2009年   35篇
  2008年   47篇
  2007年   47篇
  2006年   52篇
  2005年   44篇
  2004年   50篇
  2003年   43篇
  2002年   61篇
  2001年   24篇
  2000年   14篇
  1999年   22篇
  1998年   20篇
  1997年   20篇
  1996年   25篇
  1995年   23篇
  1994年   20篇
  1993年   28篇
  1992年   14篇
  1991年   27篇
  1990年   19篇
  1989年   21篇
  1988年   25篇
  1987年   18篇
  1986年   17篇
  1985年   23篇
  1984年   13篇
  1983年   22篇
  1982年   21篇
  1981年   25篇
  1980年   15篇
  1979年   12篇
  1978年   18篇
  1977年   19篇
  1976年   14篇
  1975年   7篇
  1974年   7篇
  1973年   7篇
  1972年   5篇
排序方式: 共有1480条查询结果,搜索用时 15 毫秒
221.
The objective measurement of physical activity using accelerometers is becoming increasingly popular. There is little consensus, however, about how to analyze acceleration data. One promising approach is the use of reference measurements in which the subjects conduct specific activities. This makes it possible to identify data patterns that indicate these activities for each subject. The drawback of this approach is its rather high cost, in terms of both time and money. We propose a new approach in which a group of children conduct the reference measurements at the same time. We trained support vector machine models on the accelerometer data of 70 children (ages 8–11 years) to predict their activities during those reference measurements. We correctly classified activities with an accuracy of 96.9 % when fitting the individual models for each subject, and 87.5 % when fitting general models for all subjects. The obtained accuracies were comparable to results reported in previous reference measurement studies, in which each subject was measured individually. They were higher than the accuracies obtained by the traditional approach, which transfers accelerometer data to counts and classifies those on the basis of predefined cut points. We concluded that our approach can yield a valuable contribution, particularly to studies with larger samples.  相似文献   
222.
223.
We explored the dynamics of choice behavior while the values of the options changed, unannounced, several times. In particular, choice dynamics were compared when the outcome values of all available options were known (full feedback) and when the outcome value of only the chosen option was known (partial feedback). The frequency of change, the values of the options, and the difference between them were also manipulated. In an experiment with N = 427, we found that the patterns of choices were different for the two levels of feedback. Whereas behavior in the full-feedback condition showed a tendency to switch choices following a missed opportunity—replicating previous findings—the behavior in the partial-feedback condition was different. It was sensitive to the outcome value of the chosen option in comparison to some memory of the last-experienced outcome value of the unchosen option. However, the comparison of these two values influenced choice behavior only when the outcome of the currently chosen option was satisfactory and the last outcome of the unchosen one was not. As expected, the other manipulated variables (change frequency, the options’ values, and the difference between them) had no effect on the dynamics of behavior.  相似文献   
224.
As genetics and genomics become part of mainstream Medicine, these advances have the potential to reduce or exacerbate health disparities. Gaps in effective communication (where all parties share the same meaning) are widely recognized as a major contributor to health disparities. The purpose of this study was to examine GC-patient communication in real time, to assess its effectiveness from the patient perspective, and then to pilot intervention strategies to improve the communication. We observed 64 English-, 35 Spanish- and 25 Chinese-speaking (n = 124) public hospital patients and 10 GCs in 170 GC appointments, and interviewed 49 patients who were offered testing using the audio recordings to stimulate recall and probe specific aspects of the communication. Data analyses were conducted using grounded theory methods and revealed a fundamental mismatch between the information provided by GCs and the information desired and meaningful to patients. Several components of the communication that contributed to this mismatch and often resulted in ineffective communication included: (1) too much information; (2) complex terminology and conceptually difficult presentation of information; (3) information perceived as not relevant by the patient; (4) unintentional inhibition of patient engagement and question-asking; (5) vague discussions of screening and prevention recommendations. Our findings indicate a need to transform the standard model of genetic counseling communication using evidence-based principles and strategies from other fields of Medicine. The high rates of limited health literacy in the US, increasing access of diverse populations to genetic services, and growing complexity of genetic information have created a perfect storm. If not directly addressed, this convergence is likely to exacerbate health disparities in the genomic age.  相似文献   
225.
226.
We argue that the level of consensus about a set of social identity principles, and their perceived fundamentality, can influence the degree to which members perceive their group as an entity. This idea was explored through an experiment in which participants judged the entitativity of specific (in)groups on the basis of the distribution of the opinions held by their members about three identity-related principles that participants had previously rated for fundamentality. The results demonstrated that the more fundamental a principle was judged to be in comparison to other principles, the more important consensus about that principle was for producing group entitativity, relative to consensus about other principles.  相似文献   
227.
Empathy, group norms and children's ethnic attitudes   总被引:3,自引:0,他引:3  
Two minimal group studies (Ns = 150, 123) examined the impact of emotional empathy on the ethnic attitudes of 5 to 12-year old white Anglo-Australian children. Study 1 evaluated the relationship between empathy and attitudes towards a same (Anglo-Australian) versus different ethnicity (Pacific Islander) outgroup. A significant empathy × outgroup ethnicity interaction revealed that empathy was unrelated to the children's liking for the same ethnicity outgroup, but that liking for the different ethnicity outgroup increased as empathy increased. Study 2 examined the influence of empathy on attitudes towards the different ethnicity outgroup when the ingroup had a norm of inclusion versus exclusion. A significant empathy × group norm interaction revealed that empathy was unrelated to liking when the ingroup had a norm of exclusion, but that liking for the different ethnicity outgroup increased when the ingroup had a norm of inclusion. Implications of the findings for promoting children's positive attitudes to ethnic minority groups are discussed.  相似文献   
228.
229.
Memory impairment following closed-head injury (CHI) in children is well documented. Characterization of the memory deficits of children with CHI could contribute to the prediction of academic performance and rehabilitation of these children. Twenty-five children who sustained closed-head injury and 25 matched controls were administered the Rey Auditory Verbal Learning Test (AVLT). The advantage of this memory test is that a number of memory components are measured simultaneously, thus enabling us to study the relations between different aspects of memory within the same patient sample. The findings indicate that the Rey AVLT is a good test for characterization of impaired verbal memory in children following CHI. Transformation of scores derived from the Rey AVLT to Z-scores enables us to determine the relative effect of CHI in children on different memory scores. Raw scores were more vulnerable than relational ones, derived as the difference between two raw scores (e.g., learning, Trial 5 - 1), to closed-head injury in children, and scores reflecting word span were the least vulnerable. The results are discussed in terms of the possible contribution of the frontal lobes, which are frequently affected in closed-head injuries, to memory performance.  相似文献   
230.
Data from the Children in the Community Study, a community-based longitudinal study were used to investigate associations between paternal psychiatric disorders and child-rearing behaviors. Paternal psychiatric symptoms and behavior in the home were assessed among 782 families during the childhood and adolescence of the offspring. Paternal anxiety, disruptive, mood, personality, and substance use disorders were independently associated with specific types of maladaptive paternal behavior in the home during the child-rearing years after paternal age, education, income, co-occurring paternal psychiatric symptoms, offspring age, sex, intelligence, temperament, and psychiatric symptoms were controlled statistically. Paternal psychiatric disorders that were present by mean offspring age 14 were associated with elevated risk for maladaptive paternal behavior in the home at mean age offspring 16, after prior maladaptive paternal behavior was controlled statistically. These findings suggest that paternal psychiatric disorder may be an important determinant of maladaptive paternal behavior in the home during the child-rearing years. Improved recognition and treatment of paternal psychiatric disorders may help to reduce the amount of maladaptive parenting behavior that many children and adolescents might otherwise be likely to experience.  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