全文获取类型
收费全文 | 5041篇 |
免费 | 34篇 |
国内免费 | 3篇 |
专业分类
教育 | 3424篇 |
科学研究 | 532篇 |
各国文化 | 45篇 |
体育 | 334篇 |
综合类 | 9篇 |
文化理论 | 47篇 |
信息传播 | 687篇 |
出版年
2023年 | 23篇 |
2022年 | 35篇 |
2021年 | 39篇 |
2020年 | 83篇 |
2019年 | 135篇 |
2018年 | 194篇 |
2017年 | 224篇 |
2016年 | 206篇 |
2015年 | 126篇 |
2014年 | 172篇 |
2013年 | 843篇 |
2012年 | 162篇 |
2011年 | 195篇 |
2010年 | 157篇 |
2009年 | 138篇 |
2008年 | 125篇 |
2007年 | 156篇 |
2006年 | 98篇 |
2005年 | 115篇 |
2004年 | 95篇 |
2003年 | 95篇 |
2002年 | 80篇 |
2001年 | 106篇 |
2000年 | 91篇 |
1999年 | 77篇 |
1998年 | 66篇 |
1997年 | 59篇 |
1996年 | 55篇 |
1995年 | 37篇 |
1994年 | 51篇 |
1993年 | 27篇 |
1992年 | 57篇 |
1991年 | 52篇 |
1990年 | 45篇 |
1989年 | 46篇 |
1988年 | 42篇 |
1987年 | 38篇 |
1986年 | 40篇 |
1985年 | 45篇 |
1984年 | 40篇 |
1983年 | 26篇 |
1982年 | 40篇 |
1981年 | 29篇 |
1979年 | 38篇 |
1978年 | 36篇 |
1977年 | 23篇 |
1976年 | 24篇 |
1974年 | 22篇 |
1972年 | 26篇 |
1971年 | 21篇 |
排序方式: 共有5078条查询结果,搜索用时 15 毫秒
981.
Carol McDonald Connor Ralph Radach Christian Vorstius Stephanie L. Day Leigh McLean Frederick J. Morrison 《Scientific Studies of Reading》2015,19(2):114-134
In this study, we investigated fifth graders’ (n = 52) fall literacy, academic language, and motivation and how these skills predicted fall and spring comprehension monitoring on an eye movement task. Comprehension monitoring was defined as the identification and repair of misunderstandings when reading text. In the eye movement task, children read two sentences; the second included either a plausible or implausible word in the context of the first sentence. Stronger readers had shorter reading times overall suggesting faster processing of text. Generally fifth graders reacted to the implausible word (i.e., longer gaze duration on the implausible vs. the plausible word, which reflects lexical access). Students with stronger academic language, compared to those with weaker academic language, generally spent more time rereading the implausible target compared to the plausible target. This difference increased from fall to spring. Results support the centrality of academic language for meaning integration, setting standards of coherence, and utilizing comprehension repair strategies. 相似文献
982.
Eric R. Muoz Jaclyn B. Caccese Brittany E. Wilson Kyle T. Shuler Fernando V. Santos Carolina T. Cabn John J. Jeka Dianne Langford Matthew B. Hudson 《运动与健康科学(英文)》2021,10(2):122-130
BackgroundConsidering the potential cumulative effects of repetitive head impact (HI) exposure, we need sensitive biomarkers to track short- and long-term effects. Circulating small extracellular vesicles (sEVs) (<200 nm) traffic biological molecules throughout the body and may have diagnostic value as biomarkers for disease. The purpose of this study was to identify the microRNA (miRNA) profile in circulating sEVs derived from human plasma following repetitive HI exposure.MethodsHealthy adult (aged 18–35 years) soccer players were randomly assigned to one of 3 groups: the HI group performed 10 standing headers, the leg impact group performed 10 soccer ball trapping maneuvers over 10 min, and the control group did not participate in any soccer drills. Plasma was collected before testing and 24 h afterward, and sEVs were isolated and characterized via nanoparticle tracking analysis. Next-generation sequencing was utilized to identify candidate miRNAs isolated from sEVs, and candidate microRNAs were analyzed via quantitative polymerase chain reaction. In silico target prediction was performed using TargetScan (Version 7.0; targetscan.org) and miRWalk (http://mirwalk.umm.uni-heidelberg.de/) programs, and target validation was performed using luciferase reporter vectors with a miR-7844-5p mimic in human embryonic kidney (HEK) 293T/17 cells.ResultsPlasma sEV concentration and size were not affected across time and group following repetitive HI exposure. After 24 h, the HI read count from next-generation sequencing showed a 4-fold or greater increase in miR-92b-5p, miR-423-5p, and miR-24-3p and a 3-fold or greater decrease in miR-7844-5p, miR-144-5p, miR-221-5p, and miR-22-3p. Analysis of quantitative polymerase chain reaction revealed that leg impact did not alter the candidate miRNA levels. To our knowledge, miR-7844-5p is a previously unknown miRNA. We identified 8 miR-7844-5p mRNA targets: protein phosphatase 1 regulatory inhibitor subunit 1B (PPP1R1B), LIM and senescent cell antigen-like domains 1 (LIMS1), autophagy-related 12 (ATG12), microtubule-associated protein 1 light chain 3 beta (MAP1LC3B), integrin subunit alpha-1 (ITGA1), mitogen-activated protein kinase 1 (MAPK1), glycogen synthase kinase 3β (GSK3β), and mitogen-activated protein kinase 8 (MAPK8).ConclusionCollectively, these data indicate repetitive HI exposure alters plasma sEV miRNA content, but not sEV size or number. Furthermore, for the first time we demonstrate that previously unknown miR-7844-5p targets mRNAs known to be involved in mitochondrial apoptosis, autophagy regulation, mood disorders, and neurodegenerative disease. 相似文献
983.
The aim of this study was to examine the effects of muscle-tendon length on joint moment and power during maximal sprint starts. Nine male sprinters performed maximal sprint starts from the blocks that were adjusted either to 40 degrees or 65 degrees to the horizontal. Ground reaction forces were recorded at 833 Hz using a force platform and kinematic data were recorded at 200 Hz with a film camera. Joint moments and powers were analysed using kinematic and kinetic data. Muscle - tendon lengths of the medial gastrocnemius, soleus, vastus medialis, rectus femoris and biceps femoris were calculated from the set position to the end of the first single leg contact. The results indicated that block velocity (the horizontal velocity of centre of mass at the end of the block phase) was greater (P < 0.01) in the 40 degrees than in the 65 degrees block angle condition (3.39 +/- 0.23 vs. 3.30 +/- 0.21 m . s(-1)). Similarly, the initial lengths of the gastrocnemius and soleus of the front leg in the block at the beginning of force production until half way through the block phase were longer (P < 0.001) in the 40 degrees than in the 65 degrees block angle condition. The initial length and the length in the middle of the block phase were also longer in the 40 degrees than in the 65 degrees block angle condition both for both the gastrocnemius (P < 0.01) and soleus (P < 0.01-0.05) of the rear leg. In contrast, the initial lengths of the rectus femoris and vastus medialis of the front leg were longer (P < 0.05) in the 65 degrees than in the 40 degrees block angle condition. All differences gradually disappeared during the later block phase. The peak ankle joint moment (P < 0.01) and power (P < 0.05) during the block phase were greater in the 40 degrees than in the 65 degrees block angle condition for the rear leg. The peak ankle joint moment during the block phase was greater (P < 0.05) in the 40 degrees block angle for the front leg, whereas the peak knee joint moment of the rear leg was greater (P < 0.01) in the 65 degrees block angle condition. The results suggest that the longer initial muscle-tendon lengths of the gastrocnemius and soleus in the block phase at the beginning of force production contribute to the greater peak ankle joint moment and power and consequently the greater block velocity during the sprint start. 相似文献
984.
This article examines the work of the ethics initiative in the City of Denver to see how talk about ethics contributes to an ethical culture. By paying particular attention to the communication in the city's Code of Ethics, ethics training discussion, employee interviews, and formal documents relaying the Board of Ethics’ views, we show how ethics emerges within communication. We argue that the emergent quality of ethics is dialogically refined in communication. For practitioners and officials interested in advancing organization-wide ethics training, we urge pursuing dialogical means so that people can negotiate among competing interests to shape future policy and action reflective of their ethical concerns. 相似文献
985.
对足球运动员在长期训练过程中身体准备的综合体系进行了分析。长期的研究结果表明,足球运动训练可以被划分为4个方面:1)单纯性身体活动的使用,2)不同目标训练过程的交替使用,3)较小训练周期固定结构的保留并作为训练过程的基础,4)专门性推动能力的有序发展。这4个方面可以有效地解决足球运动员全面身体准备的问题。 相似文献
986.
Christine Harold 《Critical Studies in Media Communication》2013,30(3):189-211
This essay explores the practice of “culture jamming” as a strategy of rhetorical protest. Specifically, “pranksters” deploy the tools of the mass media and marketing in order to take advantage of the resources and venues they afford. Through the concept of “pranking,” this essay suggests that the most promising forms of media activism may resist less through negation and opposition than by playfully appropriating commercial rhetoric both by folding it over on itself and exaggerating its tropes. 相似文献
987.
Optimal pricing and grant policies for museums 总被引:1,自引:0,他引:1
The “free access” policy designed by the British Government has encouraged interest in museum financial issues. We define a principal-agent model for museum administration where there are two income sources: public grants and ticket revenues. This model allows us to define the optimal contract determining public grants, ticket prices, budget and managerial effort. We find a theoretical explanation for the inelastic pricing strategy commonly adopted in cultural economics. We further find that museum manager should never have any control over the price of tickets. The model can also be applied to other institutions, such as schools or NGOs, which are able to raise funds directly from private (e.g., ticket revenues or membership fees) or public sources.
JEL Classification number H20, H42, C70, D80, Z10 相似文献
988.
Objective: To evaluate the surgical clinical results of hypertrophic obstructive cardiomyopathy. Methods: We retrospectively collected data on 24 patients who underwent surgical management in the past ten years in two hospitals in China and Madras Medical Mission in India. Myomectomy was carried out on all patients. Among them 3 patients underwent mitral valve replacement; 2 patients underwent mitral valve repair (anterior mitral leaflet plication); 2 patients underwent aortic valve replacement; 1 patient underwent aortic valve repair; 2 patients underwent aortic root replacement; 1 patient underwent Bentall's procedure and 1 patient underwent coronary artery bypass grafting because of a breached muscle bridge, Results: One patient died of post-operative heart failure. The mean follow-up time was 4.3 years, There was significant improvement in the symptomatic status. Sixteen patients were asymptomatic with good effort tolerance and only four patients had New York heart association (NYHA) Classes Ⅰ-Ⅱ due to associated valvular lesions, Conclusion: Our experience proved that symptomatic hypertrophic obstructive cardiomyopathy or non-symptomatic hypertrophic obstructive cardiomyopathy with combined heart disease is indication for surgery as surgical intervention could get better clinical results in this kind of patients compared with other non-surgical method because it beneficially reduces the systolic anterior motion (SAM) of the mitral valve leaflet, which could not be avoided by other non-surgical treatment. 相似文献
989.
Christine Van Peer 《Compare》2006,36(1):105-123
In 1996–1997, within the framework of the European Observatory for Population Education and Information, a comparative survey was conducted among students in final classes of secondary education in several European countries. On the one hand, the survey attempted to assess the effects of education on population in terms of knowledge acquired; the issues addressed in the questionnaire pertained to knowledge of demographic facts and trends (such as the ageing of Western societies and immigration). On the other hand it tried to ascertain students' opinions on demographic trends. What are young people's views on intergenerational solidarity, how tolerant are they towards immigrants, what are their views on recent changes in family structures? This knowledge is important since it is young people's attitudes and future behaviour that will help to shape both the social tissue and the economic prosperity of the European and world population. In this article we present a comparative analysis of survey results obtained in five European countries. We examined the question whether knowledge acquired in the course of scolarisation influences opinions. The results evidence a significant relationship between knowledge of the migrants' issue and attitudes of tolerance towards migrants. By means of multivariate analyses, the impact of factors such as social origin, study orientation and gender on both students' knowledge and attitudes, are investigated. We conclude that adequate educational training on population issues can have a significant positive impact on attitudes of tolerance. 相似文献
990.
Christine Bieri Buschor Christa Kappler Andrea Keck Frei Simone Berweger 《Gender and education》2014,26(7):743-758
The study examines the career decision-making of Swiss academic high school students opting for a career in a non-traditional, gender-typed area of work during the transition to higher education. Based on a longitudinal study, a qualitative study with 11 female students in Science, Technology, Engineering and Mathematics (STEM) and 13 male student teachers was conducted in order to analyse their perceptions of the career decision-making process. They felt supported by their parents and teachers. Women showed a strong sense of identity as future scientists without mentioning specific career goals. Men, by contrast, referred to job security-related considerations and emphasised the importance of role models for their choice. Female students emphasised their status of being ‘unique in a men's world' whereas male student teachers highlighted the role of ‘masculinity in the classroom'. 相似文献