全文获取类型
收费全文 | 1271篇 |
免费 | 53篇 |
专业分类
教育 | 1018篇 |
科学研究 | 33篇 |
各国文化 | 22篇 |
体育 | 49篇 |
文化理论 | 5篇 |
信息传播 | 197篇 |
出版年
2023年 | 7篇 |
2022年 | 22篇 |
2021年 | 19篇 |
2020年 | 43篇 |
2019年 | 58篇 |
2018年 | 77篇 |
2017年 | 90篇 |
2016年 | 82篇 |
2015年 | 51篇 |
2014年 | 50篇 |
2013年 | 263篇 |
2012年 | 57篇 |
2011年 | 46篇 |
2010年 | 36篇 |
2009年 | 39篇 |
2008年 | 37篇 |
2007年 | 30篇 |
2006年 | 20篇 |
2005年 | 29篇 |
2004年 | 28篇 |
2003年 | 28篇 |
2002年 | 17篇 |
2001年 | 11篇 |
2000年 | 10篇 |
1999年 | 21篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 7篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 14篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1907年 | 2篇 |
1903年 | 2篇 |
排序方式: 共有1324条查询结果,搜索用时 15 毫秒
1.
C A Perry 《Bulletin of the Medical Library Association》1990,78(3):271-282
Efforts to represent knowledge effectively have been central to progress in various aspects of medical informatics. These efforts range from relatively simple "electronic textbooks" to fairly sophisticated knowledge-based systems, which function as well as, or even better than, human experts faced with similar problems. Knowledge bases have been developed in many fields, but the relatively limited domains and structured language of medicine, as well as the importance of information in the provision of good medical care, have made research in medical knowledge representation an area of intense activity. This paper reviews representative knowledge bases and knowledge-based systems in medicine: electronic textbooks such as PDQ and the Hepatitis Knowledge Base (HKB), rule-based systems such as MYCIN, causal models (e.g., CASNET), and hypothesis- or frame-based systems, exemplified by PIP and INTERNIST-1. The paper describes the relationships among divergent approaches and provides a sense of current and future trends. It examines problems in knowledge-based systems, particularly in knowledge representation and acquisition, and the responses to these challenges. The latter include the use of domain-independent software shells for constructing knowledge bases, the adaptation and use of previously existing knowledge bases, and multiple uses of the same knowledge base for different purposes. 相似文献
2.
Black-dyed artefacts are found in museums worldwide, many produced using an iron-tannate compound. Deterioration of iron-tannate dyed artefacts is an international preservation issue: in New Zealand the deterioration of paru (iron-tannate) dyed Māori textiles is widespread. This article reports experimental work testing the efficacy of sodium alginate, a consolidant developed for deteriorated paru-dyed muka (fibre from harakeke; Phormium tenax). The colour stability, strength retention, and acidity of paru-dyed muka consolidated with sodium alginate (0.25, 0.5, and 1% w/v in water) was tested pre- and post-artificial light ageing. This study found that sodium alginate had no negative effect on paru-dyed muka and in some cases provided benefit. Interestingly, the colour of paru-dyed muka is substantially more stable in UV-filtered light than previously recognised. Also microfading results were in agreement with visual assessments of colour change at 1 Mlux hour exposure, providing confidence in this relatively new technique to assess colour change. 相似文献
3.
Cyberbullying is an increasingly common experience that produces psychosocial consequences for targets. Interventions encouraging bystanders to support targets of cyberbullying are limited by a lack of focus on what to communicate. This study considers supportive messages that emphasize emotional comfort, attributions of responsibility, and beliefs that people can change as relevant to this context, and it examines how perceptions of messages differ based on whether support providers have or lack experience with cyberbullying. We extend research on the indirect effects model of supportive communication by randomly assigning participants (N?=?304), who self-identify as targets of cyberbullying, to message and source conditions and assessing their perceptions of messages, providers, and outcomes. Impressions of messages mediate their influence on outcomes, and the experiential similarity of support providers moderates these effects. Certain messages, notably those contending that bullies can change, are less effective when delivered by sources who lack experience with bullying. 相似文献
4.
Rachel Ivy Clarke 《Library & information science research》2018,40(3-4):255-261
“How we done it good” publications—a genre concerning project-based approaches that describe how (and sometimes why) something was done—are often rebuked in the library research community for lacking traditional scientific validity, reliability, and generalizability. While scientific methodologies may be a common approach to research and inquiry, they are not the only methodological paradigms. This research posits that the how we done it good paradigm in librarianship reflects a valid and legitimate approach to research. By drawing on the concept of research through design, this study shows how these how we done it good projects reflect design methodologies which draw rigor from process, invention, relevance, and extensibility rather than replicability, generalizability, and predictability. Although these projects implicitly reflect research through design, the methodology is not yet explicitly harnessed in librarianship. More support for these types of projects can be achieved by making the legitimate design framework more explicit and increasing support from publication venues. 相似文献
5.
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
6.
Mallory Bolenbaugh Megan Foley-Nicpon Rachel Young Melissa Tully Nikki Grunewald Marizen Ramirez 《Psychology in the schools》2020,57(11):1657-1679
Cyberbullying is a major health concern for today's youth and a pervasive stressor for adolescents and their families. This study offers qualitative insights into how parents perceive their children's technology use and engagement in cyberbullying based on gender. Eight focus groups were conducted with 48 parents of adolescents ages 10–17. Findings indicated parents perceived their children overuse technology and lack awareness of what cyberbullying is. Specific to gender, parents suggested their daughters use technology for social connection, and parents were more concerned about their daughter's technology use than their son's, which they believed was related to specific interests. In response to cyberbullying scenarios, parents encouraged females but not males to socialize with peers. This is the first qualitative study to obtain an in-depth understanding of the ways in which parents perceive and socialize their children in regard to technology use and cyberbullying scenarios. These results may help school systems, school psychologists, researchers, and parents gain awareness of the gender-stereotypical socialization process that unfolds in parental monitoring of technology use and cyberbullying situations. We conclude by offering suggestions for how school systems and personnel might intervene. 相似文献
7.
8.
Engagement in problem‐solving and mathematical discussion is critical for learning mathematics. This research review describes a gap in the literature surrounding engagement of students with Learning Disabilities in standards‐based mathematical classrooms. Taking a sociocultural view of engagement as participation in mathematical practices, this review found that students with LD were supported towards equal engagement in standards‐based mathematics through multi‐modal curriculum, consistent routines for problem‐solving, and teachers trained in Mathematical Knowledge for Teaching. Using this small set of studies (7), we identify the need to deepen the engagement of students with LD in mathematical problem‐solving and discussion. This review concludes with implications for teaching and learning. 相似文献
9.
Rachel Cook 《Environmental Education Research》2017,23(1):145-148
10.