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   81篇
  免费   2篇
教育   57篇
科学研究   13篇
体育   4篇
信息传播   9篇
  2023年   1篇
  2021年   1篇
  2018年   2篇
  2017年   2篇
  2016年   2篇
  2013年   17篇
  2012年   1篇
  2011年   5篇
  2010年   2篇
  2009年   2篇
  2008年   9篇
  2007年   3篇
  2006年   2篇
  2005年   5篇
  2004年   2篇
  2003年   3篇
  2002年   1篇
  1997年   2篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1984年   1篇
  1982年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1920年   5篇
  1919年   1篇
  1918年   1篇
  1910年   2篇
  1889年   1篇
  1859年   2篇
  1840年   1篇
排序方式: 共有83条查询结果,搜索用时 15 毫秒
1.
We present an overview of previous research results on the molecular phylogenetic analyses in Agaricales and its higher ranks (Agaricomycetes/Agaricomycotina/Basidiomycota) along with the most recent treatments of taxonomic systems in these taxa. Establishing phylogenetic hypotheses using DNA sequences, from which an understanding of the natural evolutionary relationships amongst clades may be derived, requires a robust dataset. It has been recognized that single-gene phylogenies may not truly represent organismal phylogenies, but the concordant phylogenetic genealogies from multiple-gene datasets can resolve this problem. The genes commonly used in mushroom phylogenetic research are summarized.  相似文献   
2.
The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.  相似文献   
3.
4.
5.
6.
Two experiments were performed to explore the mechanisms responsible for the increase in activity that occurs in response to stimuli which have been paired with reinforcement (SR. The first experiment showed a sharp increase in activity to SR-paired stimuli under conditions in which subjects were not required to perform any instrumental response to obtain the SR. This result seemed to rule out reinforcement of instrumental “food getting” behavior as the mechanism responsible for the learned activity increases. A second experiment used an “omission training” procedure to further explore the mechanisms underlying the activity increase. In this experiment, SR was omitted on those trials on which activity increases were present during the stimulus. In this condition, no increases in activity were observed during the stimulus. There was, however, the characteristic increase in activity in a yoked-control group which received the same number and distribution of stimulus-paired SRs. The results of the second experiment open the possibility that increases in activity to SR -paired stimuli could be due to the adventitious reinforcement of motor behavior rather than the Pavlovian conditioning of a motivational state.  相似文献   
7.
Numerous studies have been conducted on the impact of dual-earner parents' employment on their children, yet the reverse process-the impact of children and their behavior on the work functioning of their parents-has been ignored. This study investigated spillover from the mother role to the work role in a sample of more than 300 families. At 4 months, 12 months, 3.5 years, and 4.5 years of age, child's difficult temperament was significantly associated with mother's work outcomes, including work role quality and rewards from combining work and family. The evidence was consistent with a structural model in which maternal sense of parenting competence and maternal depressed affect mediated these effects.  相似文献   
8.
This article reports on the experiences of deaf and hard of hearing students at a Queensland university, which offers an extensive deaf student support program. Seventy‐two current students and graduates since the program’s inception twenty years ago completed a survey about their experiences, highlights, challenges and use of communication tools and support services at university. Findings indicate, both quantitatively and qualitatively, that students valued the specialised support services they received, although challenges in accessing the academic curriculum remained for many students. In the important area of social factors, many students reported enjoying satisfying friendships and a sense of belonging with other deaf people, often for the first time, while others experienced feelings of social isolation in a largely hearing peer group. Overall, deaf and hard of hearing students who had attended Griffith over the 20 years had a high rate of graduation, comparing favourably with other university students.  相似文献   
9.
Findings of a study that investigated parents' expectations and experiences of their children's outcomes with cochlear implants are presented. A survey completed by 247 parents whose children had received implants in eastern Australia compared parents' reports of their preimplant expectations with their experiences of postimplant outcomes on several items related to communication, academic, and psychosocial domains. Quantitative findings derived from the survey data were extended and elaborated on by qualitative findings from interviews with 27 of the parents. The findings indicated that parents' relatively high expectations of their children's outcomes largely had been met, although a tenth of survey respondents reported that their expectations had not been met. It appeared that professionals generally provided parents with realistic expectations. The qualitative findings revealed a complex interaction among parents' expectations, hopes, and determination that their children would do well with the implant. Implications for professionals are discussed.  相似文献   
10.
Given the impact of austerity on higher education systems, an intellectual concern with the impact of austerity on faculty seems appropriate. In this article, austerity is explored through the everyday lived experience of faculty and its impact on both their personal and professional contexts. This aspect has been under-researched in the higher education literature and addresses the complexities and contradictions that the austerity can create for faculty. The study located in the Republic of Ireland provides an interesting context as the global financial crisis in 2008 resulted in 9 years of austerity measures that impacted on all aspects of the economy and particularly on the higher education sector. A social realist approach using Archer’s morphogenetic framework was employed. The framework facilitated an in-depth understanding of the relationship between structure, culture and agency and how austerity was experienced by faculty within their institutions.  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