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   22720篇
  免费   351篇
  国内免费   31篇
教育   16312篇
科学研究   2023篇
各国文化   204篇
体育   1737篇
综合类   34篇
文化理论   216篇
信息传播   2576篇
  2022年   136篇
  2021年   232篇
  2020年   375篇
  2019年   515篇
  2018年   709篇
  2017年   790篇
  2016年   737篇
  2015年   434篇
  2014年   593篇
  2013年   4262篇
  2012年   580篇
  2011年   639篇
  2010年   493篇
  2009年   460篇
  2008年   524篇
  2007年   504篇
  2006年   442篇
  2005年   387篇
  2004年   365篇
  2003年   329篇
  2002年   383篇
  2001年   425篇
  2000年   400篇
  1999年   402篇
  1998年   211篇
  1997年   230篇
  1996年   257篇
  1995年   215篇
  1994年   214篇
  1993年   195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   256篇
  1985年   323篇
  1984年   266篇
  1983年   256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 0 毫秒
231.
This study presents a worked example of a stepped process to reliably estimate the habitual physical activity and sedentary time of a sample of young children. A total of 299 children (2.9 ± 0.6 years) were recruited. Outcome variables were daily minutes of total physical activity, sedentary time, moderate to vigorous physical activity and proportional values of each variable. In total, 282 (94%) provided 3 h of accelerometer data on ≥1 day and were included in a 6-step process: Step-1: determine minimum wear-time; Step-2: process 7-day-data; Step-3: determine the inclusion of a weekend day; Step-4: examine day-to-day variability; Step-5: calculate single day intraclass correlation (ICC) (2,1); Step-6: calculate number of days required to reach reliability. Following the process the results were, Step-1: 6 h was estimated as minimum wear-time of a standard day. Step-2: 98 (32%) children had ≥6 h wear on 7 days. Step-3: no differences were found between weekdays and weekend days (P ≥ 0.05). Step-4: no differences were found between day-to-day variability (P ≥ 0.05). Step-5: single day ICC’s (2,1) ranged from 0.48 (total physical activity and sedentary time) to 0.53 (proportion of moderate to vigorous physical activity). Step-6: to reach reliability (ICC = 0.7), 3 days were required for all outcomes. In conclusion following a 7 day wear protocol, ≥6 h on any 3 days was found to have acceptable reliability. The stepped-process offers researchers a method to derive sample-specific wear-time criterion.  相似文献   
232.
1.Introduction The reproduction systems of 3D images without using eyeglasses and other special accessories has always attracted attention and aroused great interest of developers and consumers of such equipment because of totally accurate image and method of its presentation.Such systems can be used and are already partially used in advertising,television,different devices (i.e.smartphones,tablet computers),at the exhibitions,etc.,as well as in various technical applications,training systems,simulators,etc.  相似文献   
233.
234.
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   
235.
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   
236.

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   
237.
The purpose of this study was to investigate whether a linear factor analytic method commonly used to investigate violation of the item response theory (IRT) unidimensionality assumption is sensitive to measurable curricular differences within a school district and to examine the possibility of differential item performance for groups of students receiving different instruction. For grades 3 and 6 in reading and mathematics, personnel from two midwestern school systems that regularly administer standardized achievement tests identified the formal textbook series used and provided ratings of test-instructional match for each school building (classroom). For both districts, the factor analysis results suggested no differences in percentages of variance for large first factors and relatively small second factors across ratings or series groups. The IRT analyses indicated little, if any, differential item performance for curricular subgroups. Thus, the impact of factors that might be related to curricular differences was judged to be minor.  相似文献   
238.
The early stages of empathy in counseling—emotional reaction, role-taking, and cognitive suspension—have all been largely ignored in the counselor education/psychological literature. This article describes these stages from the perspective of the aesthetic/film literatures. Emotional reaction is an internal, unobservable state of being. Role-taking involves cognitive understanding and entering the perceptual world of another. Cognitive suspension means letting go of personal beliefs and values. The film literature describes how audience emotional states are created by directors, writers, actors, and editors. This article explains how counselor educators and supervisors can use this information to help counselors increase their empathic experiences.  相似文献   
239.
We are not free to choose whether anyone will learn about death, though we have some choice about how they will learn. The author discusses the basic questions that need to be answered in planning death education at any level, and the possible goals, in terms of cognitive gain, skills, and attitudinal objectives. Some principles in regard to teaching methods and evaluation are described, with illustrations from the experiences of medical students and others. It is important that the teacher should be able to deal with the problems that such programs may arouse. Cheap emotional arousal is easy to produce, but trivial, unless creatively used for a valued purpose and adequately resolved. Death is infinitely exploitable, and the growth of death voyeurism via "education" is alarming. The capacity to recognize and avoid being exploited or exploiting others must be one of our principle educational objectives.  相似文献   
240.
FLOSSWorld调查的主体由5部分构成,包括:个人(Private sector)、政府(Government sector)、开源社区参与者(Open Source participants community)、高校管理者(Heigher Education Institutes——Administrators)、高校信息部门主管(Heigher Education Institute——ITManagers)  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