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   2287篇
  免费   82篇
  国内免费   1篇
教育   1616篇
科学研究   120篇
各国文化   69篇
体育   302篇
综合类   1篇
文化理论   29篇
信息传播   233篇
  2023年   14篇
  2022年   25篇
  2021年   33篇
  2020年   78篇
  2019年   116篇
  2018年   129篇
  2017年   120篇
  2016年   150篇
  2015年   99篇
  2014年   103篇
  2013年   500篇
  2012年   74篇
  2011年   78篇
  2010年   56篇
  2009年   61篇
  2008年   72篇
  2007年   54篇
  2006年   48篇
  2005年   33篇
  2004年   32篇
  2003年   47篇
  2002年   22篇
  2001年   28篇
  2000年   18篇
  1999年   23篇
  1998年   20篇
  1997年   17篇
  1996年   15篇
  1995年   18篇
  1994年   20篇
  1993年   15篇
  1992年   17篇
  1991年   23篇
  1990年   15篇
  1989年   12篇
  1988年   16篇
  1987年   9篇
  1986年   8篇
  1985年   11篇
  1984年   14篇
  1983年   7篇
  1982年   8篇
  1981年   17篇
  1979年   11篇
  1978年   14篇
  1977年   8篇
  1974年   8篇
  1969年   5篇
  1967年   4篇
  1966年   5篇
排序方式: 共有2370条查询结果,搜索用时 15 毫秒
51.
The dominant role of English as the global language of science entails a requirement for science teachers to equip their non-native English-speaking students with receptive and productive language skills for communication in scientific contexts. Although science courses with English elements are part of some schools’ bilingual programmes, they are usually not available to a wider student audience, but are restricted to high achieving or highly motivated students. The present study was to test whether a newly developed biology content and language integrated learning (CLIL) unit could also benefit standard ninth grade classes. The learning gains and motivation of bilingually inexperienced students were compared to those of a preselected group and a comparison group that had been taught solely in their native language. All participating classes achieved similar gains in content knowledge, and the standard students rated their motivation for bilingual science lessons as positive, albeit not as high as the preselected group. We thus provide evidence against concerns that teaching non-selected students bilingually might lead to deficits in content knowledge acquisition. Following this, we conclude that scientific English should be a part of standard science lessons regardless of specific school programmes.  相似文献   
52.

Introduction

Vaspin (visceral adipose tissue-derived serpin) was first described as an insulin-sensitizing adipose tissue hormone. Recently its anti-inflammatory function has been demonstrated. Since no appropriate data is available yet, we sought to investigate the plasma concentrations of vaspin in sepsis.

Materials and methods

57 patients in intensive care, fulfilling the ACCP/SCCM criteria for sepsis, were prospectively included in our exploratory study. The control group consisted of 48 critically ill patients, receiving intensive care after trauma or major surgery. Patients were matched by age, sex, weight and existence of diabetes before statistical analysis. Blood samples were collected on the day of diagnosis. Vaspin plasma concentrations were measured using a commercially available enzyme-linked immunosorbent assay.

Results

Vaspin concentrations were significantly higher in septic patients compared to the control group (0.3 (0.1-0.4) ng/mL vs. 0.1 (0.0-0.3) ng/mL, respectively; P < 0.001). Vaspin concentration showed weak positive correlation with concentration of C-reactive protein (CRP) (r = 0.31, P = 0.002) as well as with SAPS II (r = 0.34, P = 0.002) and maximum of SOFA (r = 0.39, P < 0.001) scoring systems, as tested for the overall study population.

Conclusion

In the sepsis group, vaspin plasma concentration was about three-fold as high as in the median surgical control group. We demonstrated a weak positive correlation between vaspin and CRP concentration, as well as with two scoring systems commonly used in intensive care settings. Although there seems to be some connection between vaspin and inflammation, its role in human sepsis needs to be evaluated further.Key words: adipocytokine, inflammation, vaspin, CRP, intensive care  相似文献   
53.
54.
Whether high quantities of center-based care cause behavior problems is a controversial question. Studies using covariate adjustment for selection factors have detected relations between center care and behavior problems, but studies with stronger internal validity less often find such evidence. We examined whether within-child changes in hours in center-based care predicted changes in externalizing problems in toddlers and preschoolers (N = 10,105; 49% female; data collection 1993–2012) in seven studies, including from Germany, Netherlands, Norway, two from Canada and two from the U.S. Race/ethnicity data were only collected in the United States (57% and 80% White; 42% and 13% African-American; 1.2% and 5% Latinx). Meta-analyses showed no association (r = .00, p = .88) between hours in center-based care and externalizing problems.  相似文献   
55.
Stereotypes, which are based on the categorization process, are learned. Children first acquire a category of a social group and subsequently attribute characteristics to the group (i.e., form a stereotype). This paper illuminates the development of stereotypes among young children on the basis of cognitive theories of conceptual development. Specifically, several studies investigating the concept formation of “the Arab” among Jewish children in Israel are reported. These studies concern the five following research questions: When do children acquire the concept “an Arab”? On what basis do children form the concept “an Arab”? How do children understand the concept “an Arab”? What is the affective meaning of the concept “an Arab”? What is the visual image of “an Arab” in the minds of children? The results of the reported studies show that children acquire the word and the concept “an Arab” very early. From the beginning, even though little knowledge is associated with the concept, it has negative connotations. Young children described Arabs mostly by referring to violent and aggressive behaviors, and the characterization was unidimensional. These results demonstrate the strength of the Israeli cultural stereotype of Arabs and its influence on young children on the one hand, and show the general principles of category and stereotype development, on the other.  相似文献   
56.
Unidimensionality and local independence are two common assumptions of item response theory. The former implies that all items measure a common latent trait, while the latter implies that responses are independent, conditional on respondents’ location on the latent trait. Yet, few tests are truly unidimensional. Unmodeled dimensions may result in test items displaying dependencies, which can lead to misestimated parameters and inflated reliability estimates. In this article, we investigate the dimensionality of interim mathematics tests and evaluate the extent to which modeling minor dimensions in the data change model parameter estimates. We found evidence of minor dimensions, but parameter estimates across models were similar. Our results indicate that minor dimensions outside the primary trait have negligible consequences on parameter estimates. This finding was observed despite the ratio of multidimensional to unidimensional items being above previously recommended thresholds.  相似文献   
57.
Widening participation programmes aim to increase the progression of students from low socio‐economic status (SES) groups to higher education. This research proposes that the human capabilities approach is a good justice‐based framework within which to consider the social and cultural capital processes that impact upon the educational capabilities of young people from low SES groups. It presents a case study which examines the developing capability set of Irish students from a representative sample of schools participating in a university‐based widening participation outreach programme aimed at increasing social and cultural capital constructs. Qualitative analysis is presented from four schools; four student focus groups with 22 student participants, and 15 individual student interviews. Findings focus on the developing capabilities of autonomy, hope, voice and identity, as well as on the relationship between specific widening participation activities and the developing capability set. The findings highlight the development of college‐focused knowledge and how this impacts upon students’ aspiration to participate in higher education. The idea of ‘widening capability’ is discussed in relation to the potential of the capability approach to contribute an additional dimension to a mainly neoliberal policy rhetoric, which emphasises the market value of higher‐education participation. In doing so, it explores how widening participation activities can influence the widening capability set of low SES students, and its relationship with what the students deem to be ‘a life of value’.  相似文献   
58.
Abstract

In spite of the increased acceptance of artificial turf in football, few studies have investigated if matches are altered by the type of surface used and no research has compared physiological responses to football activity on artificial and natural surfaces. In the present study, participants performed a football match simulation on high-quality artificial and natural surfaces. Neither mean heart rate (171 ± 9 beats · min?1 vs. 171 ± 9 beats · min?1; P > 0.05) nor blood lactate (4.8 ± 1.6 mM vs. 5.3 ± 1.8 mM; P > 0.05) differed between the artificial and natural surface, respectively. Measures of sprint, jumping and agility performance declined through the match simulation but surface type did not affect the decrease in performance. For example, the fatigue index of repeated sprints did not differ (P > 0.05) between the artificial, (6.9 ± 2.1%) and natural surface (7.4 ± 2.4%). The ability to turn after sprinting was affected by surface type but this difference was dependent on the type of turn. Although there were small differences in the ability to perform certain movements between artificial and natural surfaces, the results suggest that fatigue and physiological responses to football activity do not differ markedly between surface-type using the high-quality pitches of the present study.  相似文献   
59.
We hypothesised that resiliency may protect adolescents against risky behaviours, and that both the practicing of sports, and gender are moderating variables in relationships between resiliency and risky behaviours. The study included 18-year-old pupils from a selection of secondary schools (n = 556). A total of 188 individuals practiced competitive sports and the remaining 368 participants were non-athletes. The participants were examined with the Resiliency Assessment Scale for Children and Adolescents (SPP-18) and with a survey containing questions and statements related to high-risk “experiments with adulthood”. Adolescent athletes showed higher levels of resiliency than their peers. The power of the “Determination and Persistence in Action” effect on “Alcohol” scale differed significantly between male athletes and male non-athletes. Only in the athletes groups were higher scores on this scale reflected by lower values on the “Drugs” scale. Moreover, it is possible to observe differences in undertaking risky behaviour between male and female athletes. The analysis of risky sexual behaviour suggests that sport is a risk factor for men, and a protective factor for women. These data suggest that consistent prophylactic and psycho-educative activities, with a special attention to differences between genders, should be provided to all the adolescents, irrespective of their sport performance levels.  相似文献   
60.
We used data from the 2014–2015 easyCBM assessment system to explore the applied reading intervention characteristics in a sample of 3,074 Grade 1 students (and 5,145 interventions) in school districts applying a multitiered systems of support (MTSS) framework. We describe the number of interventions, number of assessments, the intervention start dates, curricula, instructional strategies, tier, group size, frequency, dosage, total time, and quantitative intensity. We found variance across all instructional variables, with 156 curricula and 59 instructional strategies applied. Based on our data, a “typical” intervention was a Tier 2 intervention that began before October, was delivered for 30 minutes/day for 5 days/week in a group with three to five students, was changed once if at all, and student progress was most likely monitored with word reading fluency measures.  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