全文获取类型
收费全文 | 12349篇 |
免费 | 173篇 |
国内免费 | 122篇 |
专业分类
教育 | 8204篇 |
科学研究 | 1350篇 |
各国文化 | 119篇 |
体育 | 1762篇 |
综合类 | 20篇 |
文化理论 | 111篇 |
信息传播 | 1078篇 |
出版年
2022年 | 96篇 |
2021年 | 123篇 |
2020年 | 241篇 |
2019年 | 334篇 |
2018年 | 442篇 |
2017年 | 440篇 |
2016年 | 393篇 |
2015年 | 284篇 |
2014年 | 359篇 |
2013年 | 2019篇 |
2012年 | 316篇 |
2011年 | 301篇 |
2010年 | 282篇 |
2009年 | 257篇 |
2008年 | 252篇 |
2007年 | 233篇 |
2006年 | 228篇 |
2005年 | 205篇 |
2004年 | 419篇 |
2003年 | 380篇 |
2002年 | 375篇 |
2001年 | 417篇 |
2000年 | 268篇 |
1999年 | 176篇 |
1998年 | 126篇 |
1997年 | 106篇 |
1996年 | 114篇 |
1995年 | 116篇 |
1994年 | 112篇 |
1993年 | 89篇 |
1992年 | 162篇 |
1991年 | 134篇 |
1990年 | 147篇 |
1989年 | 159篇 |
1988年 | 120篇 |
1987年 | 133篇 |
1986年 | 127篇 |
1985年 | 138篇 |
1984年 | 121篇 |
1983年 | 123篇 |
1982年 | 101篇 |
1981年 | 82篇 |
1980年 | 95篇 |
1979年 | 136篇 |
1978年 | 88篇 |
1977年 | 73篇 |
1976年 | 93篇 |
1974年 | 73篇 |
1973年 | 70篇 |
1971年 | 67篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
ABSTRACTLighting a cultural heritage artifact requires balancing visual perception with preventive conservation, by providing the best lighting (in terms of spectral distribution and quantity) to enable the viewer to appreciate details and color, while limiting photo-induced degradation. The paper outlines the methodology applied by a multi-disciplinary team while lighting the Shroud of Turin at its last public exhibition in 2015. The methodology considered the special requirements of the Shroud, including exposure to ultraviolet light, while providing appropriate display conditions that would meet audience expectations. The desired appearance (readability of the body image and color) was defined with the help of Shroud researchers and confirmed by subjective tests, while appropriate light levels for preservation were set in agreement with standard requirements and using knowledge of the degradation of linen in visible and UV light. The installation provided a controlled environment and a managed visitor route to the Shroud, assuring excellent perception of both details and color, with the lowest illuminance level about 15?lx. 相似文献
112.
Rosa Maria Galvão 《Cataloging & classification quarterly》2018,56(1):62-82
This article presents an empirical study focused on a qualitative analysis of the UNIMARC format. An analysis of the structural quality of the data provided by the format is evaluated to determine its current suitability for meeting the requirements and trends in data architecture for the information network and the Semantic Web. Driven by a set of quality characteristics that identify weaknesses in the data schema that cannot be bridged by simply converting data to MARC XML or RDF/XML, we conclude that the UNIMARC format is not compliant with the current metadata schema desiderata and must be replaced. 相似文献
113.
P. A. Kalachikhin 《Scientific and Technical Information Processing》2018,45(1):28-34
The issues related to funding of public research organizations are explored. The history of scientometric information systems is outlined. The advantages and disadvantages of a bibliometric approach to financing of research organizations are analyzed. The link between the assessment of the scientific and technological potential of an institution and the optimal allocation of funds is investigated. Recommendations on how to improve the efficiency of public resources allocated for scientific research are presented. 相似文献
114.
A comparison of 1,096 professional journalists in China and the United States on attitudes toward attribution and plagiarism reveals Chinese journalists were more likely to see attribution as a practice to be embraced regardless of career longevity and culture, suggesting journalistic norms are more important than a collectivist orientation. Attribution was more likely to be embraced by those who see principles as more important than expediency, affirming research that plagiarism is hardly a monolithic concept. Overall, journalists in the two nations did not vary significantly in their attitudes toward plagiarism, despite vast differences in culture and politics as well as evidence that in some other fields China is more accepting of reusing material without attribution. The data show that among journalists, attitudes toward plagiarism are shared across national boundaries, reinforcing related research showing that a journalism culture exists and is shared at least in part across national boundaries. 相似文献
115.
A rich literature exists reinforcing the notion that both perceived and received social support has stress ameliorating and protective benefits both psychologically and physiologically. However, recent literature suggests that excessive dyadic negative problem talk about an issue, a phenomenon labeled co-rumination, may reverse much of the beneficial effects of social support. Healthy young adults participated in a laboratory research study exploring the associations between co-rumination and immune system inflammatory response. Partial correlations indicated a positive association between co-rumination and C-reactive protein and a negative association between co-rumination and interleukin-6 after controlling for stress, anxiety, and temperature. Discussion focuses on the means by which co-rumination may lead to negative health outcomes. 相似文献
116.
Increased genetic testing in personalized medicine presents unique challenges for couples, including managing disease risk and potential discrimination as a couple. This study investigated couples’ conflicts and support gaps as they coped with perceived genetic discrimination. We also explored the degree to which communal coping was beneficial in reducing support gaps and ultimately stress. Dyadic analysis of married adults (N?=?266, 133 couples), in which one person had the genetic risk for serious illness, showed that perceived discrimination predicted more frequent conflicts about alpha-1 antitrypsin deficiency-related treatment, privacy boundaries, and finances, which, in turn, predicted wider gaps in emotion and esteem support, and greater stress for both spouses. Communal coping predicted lower support gaps for both partners and marginally lower stress. 相似文献
117.
Erica England Leo S. Lo Arleene P. Breaux 《Journal of Library & Information Services in Distance Learning》2018,12(1-2):3-12
This case study presents the development and implementation of a personal librarian program for a cohort-based, executive-style higher education administration doctoral program. Librarians and the program director collaborated to create a student-centered program based on individual research needs. The personal librarian program was designed to build a close relationship between the librarian and individual students; to help identify their research knowledge gaps; and to identify resources to meet each individual students' research needs. 相似文献
118.
Daniel Maier A. Waldherr P. Miltner G. Wiedemann A. Niekler A. Keinert 《Communication methods and measures》2018,12(2-3):93-118
ABSTRACTLatent Dirichlet allocation (LDA) topic models are increasingly being used in communication research. Yet, questions regarding reliability and validity of the approach have received little attention thus far. In applying LDA to textual data, researchers need to tackle at least four major challenges that affect these criteria: (a) appropriate pre-processing of the text collection; (b) adequate selection of model parameters, including the number of topics to be generated; (c) evaluation of the model’s reliability; and (d) the process of validly interpreting the resulting topics. We review the research literature dealing with these questions and propose a methodology that approaches these challenges. Our overall goal is to make LDA topic modeling more accessible to communication researchers and to ensure compliance with disciplinary standards. Consequently, we develop a brief hands-on user guide for applying LDA topic modeling. We demonstrate the value of our approach with empirical data from an ongoing research project. 相似文献
119.
This study explores science communication on Twitter by investigating a sample of tweets referring to academic papers in five different scientific fields. The specifications of science communicators on Twitter, the characteristics of those who initiate actions (by tweeting), the extent and quality of reactions (retweeting), individual and group interactions, and the distribution of tweets across types of engagement in the process of science communication (i.e., dissemination, consultation, and evaluation) were explored. A broad array of actors is involved in the communication of science on Twitter, with individual citizens and individual researchers playing an important role. In principle, this is promising for creating direct interaction, which can be difficult through more traditional mass media. The vast majority of communication activities regarding academic papers is undigested dissemination with almost no sign of debate, contestation, or collective reflection. Another general finding of this study is that bot accounts play a major role in the science communication landscape on Twitter. 相似文献
120.