全文获取类型
收费全文 | 8677篇 |
免费 | 135篇 |
国内免费 | 22篇 |
专业分类
教育 | 6130篇 |
科学研究 | 821篇 |
各国文化 | 61篇 |
体育 | 905篇 |
综合类 | 6篇 |
文化理论 | 112篇 |
信息传播 | 799篇 |
出版年
2023年 | 61篇 |
2022年 | 98篇 |
2021年 | 132篇 |
2020年 | 238篇 |
2019年 | 354篇 |
2018年 | 469篇 |
2017年 | 484篇 |
2016年 | 401篇 |
2015年 | 276篇 |
2014年 | 303篇 |
2013年 | 1601篇 |
2012年 | 277篇 |
2011年 | 236篇 |
2010年 | 208篇 |
2009年 | 191篇 |
2008年 | 186篇 |
2007年 | 199篇 |
2006年 | 173篇 |
2005年 | 121篇 |
2004年 | 125篇 |
2003年 | 132篇 |
2002年 | 97篇 |
2001年 | 140篇 |
2000年 | 154篇 |
1999年 | 114篇 |
1998年 | 98篇 |
1997年 | 79篇 |
1996年 | 95篇 |
1995年 | 67篇 |
1994年 | 69篇 |
1993年 | 50篇 |
1992年 | 85篇 |
1991年 | 83篇 |
1990年 | 75篇 |
1989年 | 85篇 |
1988年 | 92篇 |
1987年 | 72篇 |
1986年 | 86篇 |
1985年 | 77篇 |
1984年 | 63篇 |
1983年 | 75篇 |
1982年 | 63篇 |
1981年 | 47篇 |
1979年 | 60篇 |
1978年 | 56篇 |
1977年 | 42篇 |
1976年 | 51篇 |
1975年 | 39篇 |
1974年 | 40篇 |
1973年 | 36篇 |
排序方式: 共有8834条查询结果,搜索用时 625 毫秒
41.
Yu. N. Schuko 《Scientific and Technical Information Processing》2018,45(3):163-167
Although the USSR and the United States had a comparable number of employees in the field of scientific information, there was a substantial difference in funding, which resulted in a lack of information support for Soviet scientists. While 90% of the publications in the United States were available almost immediately after their release, in the USSR they were delayed by 1.5 to 2 years. Since the publication of the Abstracts Journal by VINITI (AJ), its content was consistently expanding and reached its peak in 1990 (1.5 million documents per year). The next quarter of a century was characterized by a decline in both the composition of the AJ and the time required for its document coverage. The steps for restructuring VINITI activities are discussed. The focus is made on improving the limited coverage of the Russian-language part of the global flow of scientific information by Western information systems. 相似文献
42.
Jorge Peña Subuhi Khan Christopher N. Burrows Hart Blanton 《Communication Research Reports》2018,35(4):293-302
This study examined whether persuasive health messages embedded in shooter games have broad or targeted effects on players’ willingness to engage in risk behaviors (N = 145). Participants presented with in-game health messages discouraging alcohol-impaired driving of motor vehicles showed reduced willingness to drink alcohol and to operate both motor and nonmotor vehicles, compared to those in a no-message gaming control condition. There were no spillover effects on willingness to smoke cigarettes or marijuana, thus implying targeted persuasive effects. In addition, players experiencing high instead of low cognitive load showed decreased postexperiment willingness to drink and operate nonmotor vehicles, thus suggesting that playing a game under high cognitive load can influence players’ attitudes. The findings replicate previous research and further expand on knowledge-activation and thought-disruption mechanisms underlying the persuasiveness of health messages. 相似文献
43.
Debasis?GangulyEmail authorView authors OrcID profile Gareth?J.?F.?Jones Aarón?Ramírez-de-la-Cruz Gabriela?Ramírez-de-la-Rosa Esaú?Villatoro-Tello 《Information Retrieval》2018,21(1):1-23
Automatic detection of source code plagiarism is an important research field for both the commercial software industry and within the research community. Existing methods of plagiarism detection primarily involve exhaustive pairwise document comparison, which does not scale well for large software collections. To achieve scalability, we approach the problem from an information retrieval (IR) perspective. We retrieve a ranked list of candidate documents in response to a pseudo-query representation constructed from each source code document in the collection. The challenge in source code document retrieval is that the standard bag-of-words (BoW) representation model for such documents is likely to result in many false positives being retrieved, because of the use of identical programming language specific constructs and keywords. To address this problem, we make use of an abstract syntax tree (AST) representation of the source code documents. While the IR approach is efficient, it is essentially unsupervised in nature. To further improve its effectiveness, we apply a supervised classifier (pre-trained with features extracted from sample plagiarized source code pairs) on the top ranked retrieved documents. We report experiments on the SOCO-2014 dataset comprising 12K Java source files with almost 1M lines of code. Our experiments confirm that the AST based approach produces significantly better retrieval effectiveness than a standard BoW representation, i.e., the AST based approach is able to identify a higher number of plagiarized source code documents at top ranks in response to a query source code document. The supervised classifier, trained on features extracted from sample plagiarized source code pairs, is shown to effectively filter and thus further improve the ranked list of retrieved candidate plagiarized documents. 相似文献
44.
Against the backdrop of Spain’s Transparency Act, this article discusses the presence or otherwise of a series of document types, proposed as management-related transparency indicators, on 61 (8 national and 53 provincial) historic archive websites. Although examples of good practice were identified, the information provided was found to be scant, in particular as regards lines of action, organisational objectives and yearly reports. The information most commonly provided on the websites included the collection classification chart, service use regulations and citizen charters. The inference drawn was that archives, so intently focused on their role in the application of the Act by the organisations they serve, neglect their own administrative obligations in respect of its provisions. The recommendation is that as government-funded and subsidised public service institutions, historic archives should exercise transparency by furnishing the information stipulated in the Act on their websites. 相似文献
45.
46.
47.
48.
The current study examined the link between academic enablers and different types of reading achievement measures. Academic enablers are skills and behaviors that support, or enable, students to perform well academically, such as engagement, interpersonal skills, motivation, and study skills. The sample in this study consisted of 61 third‐, fourth‐, and fifth‐grade students (54% male). Academic enablers were rated by classroom teachers via the Academic Competence Evaluation Scales (ACES; DiPerna & Elliott, 2000 ). Four different measures of reading achievement were included: classroom grades, global ratings of reading skills, standardized test scores, and Reading CBM scores. Results indicated that academic enablers were significantly related to each type of reading outcome. Academic enablers accounted for the greatest amount of variance for classroom grades (45%) and the least amount of variance in standardized test scores (11%). Results suggest that academic enablers are an important part of academic success in reading, particularly classroom grades, but when considering the variance accounted for by academic enablers, they alone are not likely to improve Reading CBM scores or standardized test scores. 相似文献
49.
Families immigrating to Australia face many challenges integrating into the educational system, including language barriers and interrupted schooling. We have qualitatively evaluated the educational concerns of Arabic migrants from Sudan and Iraq to Melbourne, Victoria, Australia, a city that receives a high percentage of Australia's immigrants. Using an interactive paradigm incorporating focus group discussions for thematic analysis, we concluded that the parents’ frame of reference for education was a more didactic style of learning. Parents viewed education as an essential part of the way forward for their children in Australia. However, it was stressful for them to try to cope with a new host nation's expectation of their involvement in their children's education while at the same time dealing with a language barrier. Professionals should look to empower parents with structural information about the key elements of the educational curriculum with minimal reliance on written technical language and match their expectations of parental involvement to the situation of the parents. 相似文献
50.