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   22753篇
  免费   409篇
  国内免费   30篇
教育   16457篇
科学研究   1987篇
各国文化   207篇
体育   1733篇
综合类   34篇
文化理论   189篇
信息传播   2585篇
  2022年   133篇
  2021年   232篇
  2020年   367篇
  2019年   500篇
  2018年   722篇
  2017年   792篇
  2016年   733篇
  2015年   439篇
  2014年   584篇
  2013年   4306篇
  2012年   574篇
  2011年   641篇
  2010年   491篇
  2009年   472篇
  2008年   530篇
  2007年   513篇
  2006年   454篇
  2005年   395篇
  2004年   372篇
  2003年   338篇
  2002年   382篇
  2001年   428篇
  2000年   400篇
  1999年   407篇
  1998年   210篇
  1997年   234篇
  1996年   258篇
  1995年   215篇
  1994年   211篇
  1993年   194篇
  1992年   304篇
  1991年   301篇
  1990年   329篇
  1989年   311篇
  1988年   295篇
  1987年   248篇
  1986年   257篇
  1985年   322篇
  1984年   266篇
  1983年   255篇
  1982年   196篇
  1981年   206篇
  1980年   176篇
  1979年   240篇
  1978年   214篇
  1977年   194篇
  1976年   160篇
  1975年   128篇
  1974年   120篇
  1973年   147篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
In America, the problem has persisted for at least a century: Are teaching and research mutually supportive, or do they tend to detract from one another? The empirical literature (due largely to measurement problems) provides an ambiguous answer, although the more recent studies have produced fairly consistently negative results. Role complementarity may depend on a range of social structural conditions, such as time allocation, whether or not roles are highly specialized, and the values around which roles are organized. In addition, the process of “compensatory selection” may reduce role complementarity as teacher/researchers move through their careers. Data for this study suggest that teaching and research tend to be mutually supportive, especially at schools where research is not emphasized.  相似文献   
212.
The main purpose of this article is to advance an alternative perspective on the relationship between intrinsic and extrinsic motivation, and in particular to examine critically the assertion that these processes are antagonistic such that the will to learn for its own sake is inhibited by the presence of extrinsic, tangible rewards and incentives such as school grades. The presumption of an antagonistic relationship largely depends on the theoretical perspective adopted. An alternative interpretation based on need achievement theory leads to distinctly different conclusions. Exploring this new perspective allows one to identify both the conditions under which intrinsic motives may coexist with extrinsic motives as well as to consider some of the means by which intrinsic motives and caring about learning can be stimulated in their own right in school settings.  相似文献   
213.
The purpose of this article was to examine the validity of self-reported pedometer steps/day. Forty-seven participants were provided a New Lifestyles NL-2000 (NL-2000; Lees Summit, MO, USA) pedometer and a physical activity (PA) diary for 3 weeks, but not informed of the data-storing capabilities. For weeks 2 and 3, each participant was given a step goal of 3,000 steps/day above week 1 average. A 2 × 3 repeated measures analysis of variance (ANOVA) was used to examine differences between reported steps/day. Bland–Altman plots assessed the mean bias and limits of agreement between reporting methods. Mean self-reported and NL-2000 steps/day were 9,264 ± 3,555 and 8,971 ± 3,590 steps/day (n = 26, p > .05). Mean biases were 216 ± 1,753 (week 1), –506 ± 1,355 (week 2), and –590 ± 1,360 (week 3) steps/day. Negative mean bias values indicate higher self-reported steps/day. Mean steps/day were similar between recording methods, but large differences were observed among individuals, suggesting self-reported steps/day may be valid for PA research at the population level, but not the individual level.  相似文献   
214.
This study examined the accuracy of self-attachment of the activPAL activity monitor. A convenience sample of 50 participants self-attached the monitor after being presented with written material only (WMO) and then written and video (WV) instructions; and completed a questionnaire regarding the acceptability of the instructional methods. Participants positioned the monitor lower than the instructed position on the thigh (WMO ?5.15 ± 2.75 cm, WV ?4.16 ± 2.15 cm; p = .008 difference) and approximately 2 cm laterally from the thigh midline (WMO 1.90 ± 0.92 cm; WV 2.08 ± 1.24 cm). The orientation of the device was positioned correctly along the midline (within < 1° of vertical). Acceptability was high for both instructional methods although preference was shown for the WV instruction. In conclusion, participants consistently self-attached the activPAL close to the intended placement with either instructional method. The addition of video instruction produced a slightly more accurate attachment and was preferred by the participants.  相似文献   
215.
Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost.  相似文献   
216.
The aim of the this study was to establish age- and gender-specific physical fitness normative values and to compare percentiles and Z scores values in a large, nationwide sample of Greek children aged 6–18 years. From March 2014 to May 2014, a total of 424,328 boys and girls aged 6–18 years who attended school in Greece were enrolled. The studied sample was representative, in terms of age–sex distribution and geographical region. Physical fitness tests (i.e. 20?m shuttle run test (SRT), standing long jump, sit and reach, sit-ups, and 10?×?5?m SRT) were performed and used to calculate normative values, using the percentiles of the empirical distributions and the lambda, mu, and sigma statistical method. Normative values were presented as tabulated percentiles for five health-related fitness tests based on a large data set comprising 424,328 test performances. Boys typically scored higher than girls on cardiovascular endurance, muscular strength, muscular endurance, and speed/agility, but lower on flexibility (all p values <0.001). Older boys and girls had better performances than younger ones (p?相似文献   
217.
We identified the perceptual–cognitive skills and player history variables that differentiate players selected or not selected into an elite youth football (i.e. soccer) programme in Australia. A sample of elite youth male football players (n?=?127) completed an adapted participation history questionnaire and video-based assessments of perceptual–cognitive skills. Following data collection, 22 of these players were offered a full-time scholarship for enrolment at an elite player residential programme. Participants selected for the scholarship programme recorded superior performance on the combined perceptual–cognitive skills tests compared to the non-selected group. There were no significant between group differences on the player history variables. Stepwise discriminant function analysis identified four predictor variables that resulted in the best categorization of selected and non-selected players (i.e. recent match-play performance, region, number of other sports participated, combined perceptual–cognitive performance). The effectiveness of the discriminant function is reflected by 93.7% of players being correctly classified, with the four variables accounting for 57.6% of the variance. Our discriminating model for selection may provide a greater understanding of the factors that influence elite youth talent selection and identification.  相似文献   
218.
The present paper focuses on the application of a structured template, maximum impact flow (MIF), in order to encourage young students in the area of optics and optical engineering. MIF introduces a template in terms of individual steps and linked functionality and is shown to fuse separate learning tools together into a cohesive unit. Prioritization and teaching structures are also discussed with the promotion of technology identified as a key factor.  相似文献   
219.

Objective

“One Health” is an interdisciplinary approach to evaluating and managing the health and well-being of humans, animals, and the environments they share that relies on knowledge from the domains of human health, animal health, and the environmental sciences. The authors'' objective was to evaluate the extent of open access (OA) to journal articles in a sample of literature from these domains. We hypothesized that OA to articles in human health or environmental journals was greater than access to animal health literature.

Methods

A One Health seminar series provided fifteen topics. One librarian translated each topic into a search strategy and searched four databases for articles from 2011 to 2012. Two independent investigators assigned each article to human health, the environment, animal health, all, other, or combined categories. Article and journal-level OA were determined. Each journal was also assigned a subject category and its indexing evaluated.

Results

Searches retrieved 2,651 unique articles from 1,138 journals; 1,919 (72%) articles came from 406 journals that contributed more than 1 article. Seventy-seven (7%) journals dealt with all 3 One Health domains; the remaining journals represented human health 487 (43%), environment 172 (15%), animal health 141 (12%), and other/combined categories 261 (23%). The proportion of OA journals in animal health (40%) differed significantly from journals categorized as human (28%), environment (28%), and more than 1 category (29%). The proportion of OA for articles by subject categories ranged from 25%–34%; only the difference between human (34%) and environment (25%) was significant.

Conclusions

OA to human health literature is more comparable to animal health than hypothesized. Environmental journals had less OA than anticipated.Keywords (Medical Subject Headings) Publishing, Periodicals as Topic, Access to Information, Veterinary Medicine, Environment, Environmental Health, Medicine“One Health” is an integrated, transdisciplinary approach to solve complex problems at the diverse interfaces shared by humans, animals, and the environment [1]. The One Health approach to evaluating and managing the health and well-being of humans, animals, and the environments that they share relies on knowledge from the domains of human health, animal health, and the environmental sciences. Although there is a growing body of literature about the development of the One Health concept as documented by Pepper, Carrigan, Shurtz, and Foster [2], this literature is not the same as the combination of literature from the three domains that is applied in service of One Health. Every discipline related to One Health has its unique mindset and language, with corresponding lists of acronyms that are frequently an impediment to effective communication across the participating professions. Relevant papers guiding a One Health approach may never specifically use “One Health” as a term or concept.To promote better communication and collaboration among health professionals and environmental scientists, a public monthly One Health Intellectual Exchange Group (IEG) hosted by the North Carolina Biotechnology Center was launched in 2009. In 2011, faculty from the North Carolina State University College of Veterinary Medicine, University of North Carolina''s Gillings School for Global Public Health, Duke Global Health Institute, and Nicholas School of the Environment at Duke University expanded the IEG series into a weekly seminar course with eight One Health focus areas [3]. The eight focus area modules were the following: an introduction to One Health; environmental health and ecology; the human and animal bond; zoonoses and emerging infectious diseases; food and water safety; disease surveillance, informatics, and disaster preparedness; benefits of comparative medicine; and policy and education (Appendix A, online only). Each seminar speaker recommended papers to read prior to the session to provide a foundation for the topic because student backgrounds and majors were quite diverse. Represented student majors included master''s of public health, master''s of animal science, doctor of veterinary medicine, graduate-level environmental sciences, and undergraduate-level biochemistry, engineering, and biology.Open access (OA) to relevant literature is very important to scholars and practitioners working on interdisciplinary problems. The One Health Proof of Concept Workgroup found that few studies assess outcomes in human, animal, and environmental spheres simultaneously [4], making it important to be able to access articles from each of the three domains to get a more complete picture.The objective of this study was to evaluate the extent of OA to journal articles in a sample of literature relevant to One Health from the human, animal, and environmental domains. Working in a college of veterinary medicine and supporting faculty, staff, and students addressing interdisciplinary problems under the One Health umbrella [5], the authors were familiar with the extent of OA in human biomedical and public health literature and the literature of veterinary medicine but were less familiar with environmental journals. In light of general availability of environmental information and OA to publications such as Environmental Health Perspectives, we thought it likely that environmental literature would be relatively open compared to the other subject areas. Therefore, we hypothesized OA to articles from human health or environmental journals was greater than access to animal health literature. We chose to look at article-level subject categorization and access, as well as journal-level categorization and access, because they might differ. Article-level access relates more to authors'' decisions about OA for a content domain, while journal-level access and subject categorization are driven by publishers and associations. Understanding the distinction and having data would inform our efforts to promote increased OA to this literature.  相似文献   
220.
Data on 1, 146 families with a child age 3 through 17 at home are presented. Child abuse information was obtained for a randomly selected child in each family. Child abuse was defined as an attack by a parent involving punching, kicking, biting, hitting with an object, “beating up,” or using a knife or gun. Over 14 out of every 100 American children 3–17 are subjected to abusive violence each year. These figures are at least 26 times greater than those of the National Center For Child Abuse and Neglect. Even so, for reasons outlined in the paper, they are underestimates. Families in which child abuse occurred are compared with other families. The results suggest that child abuse is brought about by the very nature of the society and its family system. This has profound implications for the prevention and treatment of child abuse. Although psychotherapy may be appropriate in some cases, a more fundamental approach lies in such things as a more equal sharing of the burdens of child care, replacement of physical punishment with non-violent methods of child care and training, eliminating the stresses and insecurity which now characterize our economic system, and strengthening the ties of individual families to the extended family and the community.  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