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   324篇
  免费   14篇
  2023年   3篇
  2022年   7篇
  2021年   3篇
  2020年   4篇
  2019年   9篇
  2018年   12篇
  2017年   11篇
  2016年   17篇
  2015年   16篇
  2014年   13篇
  2013年   40篇
  2012年   18篇
  2011年   14篇
  2010年   7篇
  2009年   12篇
  2008年   10篇
  2007年   17篇
  2006年   9篇
  2005年   15篇
  2004年   4篇
  2003年   7篇
  2002年   7篇
  2001年   5篇
  2000年   8篇
  1999年   2篇
  1997年   3篇
  1996年   3篇
  1995年   6篇
  1993年   2篇
  1992年   2篇
  1989年   2篇
  1988年   3篇
  1986年   2篇
  1985年   4篇
  1984年   2篇
  1983年   5篇
  1982年   1篇
  1981年   1篇
  1980年   4篇
  1979年   4篇
  1978年   1篇
  1977年   3篇
  1976年   3篇
  1974年   1篇
  1973年   3篇
  1970年   2篇
  1969年   1篇
  1967年   4篇
  1966年   1篇
  1944年   1篇
排序方式: 共有338条查询结果,搜索用时 31 毫秒
301.
Adult chimpanzees produce a unique vocal signal, the pant-grunt, when encountering higher-ranking group members. The behaviour is typically directed to a specific receiver and has thus been interpreted as a 'greeting' signal. The alpha male obtains a large share of these calls, followed by the other adult males of the group. In this study, we describe the development of pant-grunting behaviour from the first grunt-like calls of newborn babies to the fully developed pant-grunts in adults. Although babies produce grunts from very early on, they are not directed to others until about 2 months of age. Subsequently, socially directed grunting steadily increases in frequency to peak around 7 months of age, but then decreases again to reach a nadir in older infants and juveniles, while the specificity in use increases. During adolescence, grunt production increases again with grunts given most frequently to socially relevant individuals. As young chimpanzees are closely affiliated to their mothers for the first decade of their lives, we also compared the grunting patterns of mothers and their offspring, which revealed some influences in pant-grunt production. In conclusion, the acquisition of pant-grunting behaviour in chimpanzees is a long-lasting process with distinct developmental phases in which social influences by the mother and other group members are likely to play a role.  相似文献   
302.
Using a sample of 263 mother–child dyads, we examined the extent to which maternal emotional and cognitive support during a joint problem‐solving task when children were 3‐years‐old predicted children's academic skills 1 year later independent of each other, the quality of the home learning environment, and maternal emotional responsiveness. When all parenting measures were examined simultaneously, only maternal emotional support during problem solving and the quality of the home learning environment predicted unique variation in gains in pre‐academic skills from 3 to 4 years of age. The positive effect of emotional support during problem solving was especially apparent for children whose pre‐academic skills were low at the age of 3 years. These findings are discussed in light of the changing demands placed on young children and their parents as they prepare for entry to the formal school system. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
303.
Cystic fibrosis (CF) is the most common recessive condition affecting the White British population. Facilitating reproductive decision making for couples at genetic risk for CF is an important aspect of genetic counseling practice in the UK. The purpose of this study was to explore the reproductive decision making process for 31 members of CF carrier couples (15 men and 16 women) with or without an affected child. The design involved a qualitative approach consisting of semi-structured interviews and data analysis informed by grounded theory methodology. Sex and personal experience of CF were identified as factors that may influence reproductive decision making. Findings suggest these hypotheses: (1) CF carrier couples who have an affected child/pregnancy, are more likely to embark on another pregnancy than couples who have a healthy child from an at-risk pregnancy, and (2) men and women play different roles in the reproductive decision making process. Data analysis resulted in development of a structured framework modeling the reproductive decision making process, which may be helpful in guiding genetic counseling with CF carrier couples and other at risk couples making reproductive decisions.  相似文献   
304.
In this investigation, we examined the validity of Levenson's Self-Report Psychopathy Scale (LSRP; Levenson, Kiehl, & Fitzpatrick, 1995) in a sample of undergraduate students (n = 403). Utilizing a step-down hierarchical multiple regression procedure (e.g., Arbisi, Ben-Porath, & McNulty, 2002), we used LSRP scores to predict psychopathic personality traits to determine the presence of gender-moderated test bias. Results indicate similar correlational magnitudes for men and women. However, systematic over- and underprediction of scores (i.e., differential intercepts) was found for external criteria measuring key affective (i.e., low empathy) and behavioral (i.e., aggression, antisocial behavior) components of the psychopathic personality, although these effects were generally small.  相似文献   
305.
306.

Background

The aim of the present study was to compare psychological distress and substance use between migrant and non-migrant populations in a socially deprived area of Berlin.

Methods

A population-based random sample stratified for age (18?C57?years) and gender (50% female) was retrieved from the registration office. A total of 143 persons were included in the study. The participation rate was 48.5% when contact was established. Psychological distress was assessed using the General Health Questionnaire (GHQ-28) with its four subscales, somatic symptoms, anxiety/insomnia, social dysfunction and severe depression. Substance use was quantified using the Alcohol Use Identification Disorder Test (AUDIT) and the Fagerstr?m Test for Nicotine Dependence (FTND).

Results

Of the study population 51.3% were first or second generation migrants and lived more often in single households. Migrants had lower educational levels and lower employment rates. The mean scores of migrants and non-migrants did not differ on any of the subscales somatic symptoms, anxiety/depression, social dysfunction or severe depression of the GHQ-28. Non-migrants showed significantly higher risks regarding alcohol use.

Discussion

The present study did not reveal any differences regarding symptom profiles in the spectrum of anxiety and depression between non-migrants and migrants who lived in a socially deprived area. Migrants may compensate higher social risk profiles with lower risks regarding alcohol use. Larger samples have to inform on possible differences regarding smoking and other substances.  相似文献   
307.
The positive impact of sleep on memory consolidation has been shown for human subjects in numerous studies, but there is still sparse knowledge on this topic in rats, one of the most prominent model species in neuroscience research. Here, we examined the role of sleep in the object-place recognition task, a task closely comparable to tasks typically applied for testing human declarative memory: It is a one-trial task, hippocampus-dependent, not stressful and can be repeated within the same animal. A test session consisted of the Sample trial, followed by a 2-h retention interval and a Test trial, the latter examining the memory the rat had for the places of two objects presented at the Sample trial. In Experiment 1, each rat was tested twice, with the retention interval taking place either in the morning or evening, i.e., in the inactive or active phase, respectively. Rats showed significantly (p<0.01) better memory for object place after the Morning session. To control for confounding circadian factors, in Experiment 2 rats were tested four times, i.e., in the morning or in the evening while sleep was or was not deprived. Sleep during the retention interval was recorded polysomnographically. Rats only showed significant memory for the target object place in the Test trial after the Morning retention interval in the absence of sleep deprivation, and recognition performance in this condition was significantly superior to that in the three other conditions (p<0.05). EEG recordings during spontaneous morning sleep revealed increased slow oscillation (0.85-2.0 Hz) and upper delta (2.0-4.0 Hz), but reduced spindle band (10.5-13.5 Hz) activity, as compared to evening sleep. However, spindle band power was increased in the Morning retention interval in comparison to a Morning Baseline period (p<0.05). We conclude that consolidation of object-place memory depends on sleep, and presumably requires NonREM sleep rich in both slow wave and spindle activity.  相似文献   
308.
Internalists about reasons generally insist that if a putative reason, R, is to count as a genuine normative reason for a particular agent to do something, then R must make a rational connection to some desire or interest of the agent in question. If internalism is true, but moral reasons purport to apply to agents independently of the particular desires, interests, and commitments they have, then we may be forced to conclude that moral reasons are incoherent. Richard Joyce (2001) develops an argument along these lines. Against this view, I argue that we can make sense of moral reasons as reasons that apply to, and are capable of motivating, agents independently of their prior interests and desires. More specifically, I argue that moral agents, in virtue of their capacities for empathy and shared intentionality, are sensitive to reasons that do not directly link up with their pre-existing ends. In particular, they are sensitive to, and hence can be motivated by, reasons grounded in the desires, projects, commitments, concerns, and interests of others. Moral reasons are a subset of this class of reasons to which moral agents are sensitive. Thus, moral agents can be motivated by moral reasons, even where such reasons fail to link up to their own pre-existing ends.  相似文献   
309.
310.
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