全文获取类型
收费全文 | 17335篇 |
免费 | 247篇 |
国内免费 | 25篇 |
专业分类
教育 | 12211篇 |
科学研究 | 1522篇 |
各国文化 | 248篇 |
体育 | 1612篇 |
综合类 | 9篇 |
文化理论 | 222篇 |
信息传播 | 1783篇 |
出版年
2022年 | 96篇 |
2021年 | 140篇 |
2020年 | 264篇 |
2019年 | 378篇 |
2018年 | 516篇 |
2017年 | 554篇 |
2016年 | 500篇 |
2015年 | 367篇 |
2014年 | 447篇 |
2013年 | 3428篇 |
2012年 | 419篇 |
2011年 | 412篇 |
2010年 | 373篇 |
2009年 | 333篇 |
2008年 | 442篇 |
2007年 | 394篇 |
2006年 | 362篇 |
2005年 | 335篇 |
2004年 | 288篇 |
2003年 | 343篇 |
2002年 | 299篇 |
2001年 | 283篇 |
2000年 | 272篇 |
1999年 | 261篇 |
1998年 | 172篇 |
1997年 | 180篇 |
1996年 | 219篇 |
1995年 | 196篇 |
1994年 | 209篇 |
1993年 | 178篇 |
1992年 | 259篇 |
1991年 | 247篇 |
1990年 | 236篇 |
1989年 | 224篇 |
1988年 | 191篇 |
1987年 | 184篇 |
1986年 | 202篇 |
1985年 | 205篇 |
1984年 | 166篇 |
1983年 | 201篇 |
1982年 | 176篇 |
1981年 | 180篇 |
1980年 | 170篇 |
1979年 | 237篇 |
1978年 | 162篇 |
1977年 | 152篇 |
1976年 | 153篇 |
1975年 | 119篇 |
1974年 | 126篇 |
1971年 | 97篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
David Paulo 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》2002,48(3-4):259-263
International Review of Education - 相似文献
52.
53.
An investigation has been undertaken at St Andrew’s church, Walpole St Andrew, Norfolk, to establish the underlying causes of the observed stone decay to the upper parts of the six stone piers. The stone decay was first recorded in the early 1930s. The salt-contaminated masonry within the church has been shown to undergo severe salt decay during the summer, with little damage occurring over the winter months. The south aisle piers have been shown to decay 2.5 times faster than the north aisle piers. Although crystallization–hydration cycles have been identified, the rate of decay is at its greatest when the cycling is relatively infrequent. This was not the expected trend. Furthermore, it has been shown that during extended periods where the ambient relative humidity is less than 75%, the rate of decay reaches a maximum. It is the length of this ‘drying’ period that apparently has the greatest influence on the rate of decay and could explain the significant difference in the rate of decay between the south and north aisle piers. The results have serious implications for passive conservation, where it is often recommended to lower the ambient relative humidity to well below the equilibrium relative humidity of the salt contaminant, to avoid crystallization–hydration cycles. Since, at the time of building, the church was situated on the coast, it is possible that the sodium chloride contamination occurred during the building process (1440–1520), particularly since the area was prone to sea-flooding at this time. Alternatively, the salt could have been applied as a treatment during the general restoration of 1897. Whatever the source of the salt, it seems likely that the ambient environment was changed by the insertion of a sealed floor in 1897, which could account for the onset of the salt decay. 相似文献
54.
55.
Characteristics of early adopters of end-user online searching in the health professions 总被引:1,自引:0,他引:1
J G Marshall 《Bulletin of the Medical Library Association》1989,77(1):48-55
This paper examines end-user, online searching using data from a questionnaire mailed to 150 Canadian health professionals in practice settings. The response rate was 83% (n = 124). The data provide a demographic profile of early adopters of end-user searching in the health care community. Positive correlations with the user's level of implementation of end-user searching were found for the following variables: amount of time spent in research activities, amount of system training received, and use of Medical Subject Headings (MeSH). There was a negative association between the amount of time spent in patient care and implementation level. General practitioners and family physicians had lower implementation levels than physicians in other specialties. Successful implementers were more likely to be computer literate and to place a high value on formal information sources such as books, journals, and libraries. Health professionals using so-called "user-friendly" or menu-based software had lower levels of personal commitment to using online databases, as measured by a combination of continuance of use, willingness to pay personally, type of recommendations made to colleagues, and hardware ownership. 相似文献
56.
57.
This study was designed to examine children's attitudes toward the role of sports in determining social status, as well as the activities in which children prefer to participate. A total of 227 boys and 251 girls in Grades 4, 5, and 6 completed a questionnaire to determine which criteria were most important in determining personal, female, and male popularity. Personal popularity was answered by the girls and boys according to "what would make you well liked by your classmates." Female and male popularity was determined by asking both girls and boys to decide "what would make (girls, for female subjects, and boys, for male subjects) well liked by your classmates." A comparison of results from the Buchanan, Blankenbaker, and Cotten (1976) investigation and the present study indicated that, in the last 15 years, appearance has become more important and academic achievement less important in determining personal popularity for girls. For boys, the comparison revealed that sports have become more important and academic achievement less important in determining personal popularity. Boys reported sports to be the most important determinant of personal and male popularity and appearance as the most important determinant of female popularity. Sports and appearance became more important for boys with each higher grade level. Girls reported appearance to be the most important determinant of personal, male, and female popularity. For girls, appearance became more important with each higher grade level. A comparison of results from the Buchanan et al. (1976) and the present study indicated that the activities in which girls and boys preferred to participate have changed.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
58.
The Alfred Taubman Medical Library at the University of Michigan has offered instruction in online literature searching to third-year pharmacy students as a component of the course "Drug Information and Scientific Literature Evaluation" since 1983. In the spring of 1989, a follow-up study was conducted to assess the impact of instruction on four classes of graduates. Of a pool of 151 graduates, 90 (60%) responded to a mailed questionnaire on their use of information and computerized literature searching. The respondents were divided into four subgroups: end-user searchers, users of intermediaries, end users who used intermediaries, and those who did not use computerized literature search systems. Seventy-two percent of the respondents used some type of computerized literature searching, and 42% performed their own searches. The four subgroups differed in general computer use, familiarity with MEDLINE search terminology, information use, reasons for using or not using literature searching, and characteristics of searches (i.e., type, time frame, amount, and frequency). Training in end-user search systems appears to have had an impact on the continued use of computerized literature searching several years after the formal educational program. 相似文献
59.
60.
Since a sizeable hospital must have a library, it must have a library committee. Like all hospital committees, this one is to help maintain standards of medical care and to mediate between staff and administration. Unlike others, it clusters around one elected member (the chairman) and one employee (the librarian). A dynamic librarian can, and should, influence and inspire the committee's deliberations; and must be able to depend upon the support of the physician members of the committee. 相似文献