全文获取类型
收费全文 | 22448篇 |
免费 | 396篇 |
国内免费 | 30篇 |
专业分类
教育 | 16192篇 |
科学研究 | 1986篇 |
各国文化 | 203篇 |
体育 | 1713篇 |
综合类 | 34篇 |
文化理论 | 189篇 |
信息传播 | 2557篇 |
出版年
2022年 | 132篇 |
2021年 | 229篇 |
2020年 | 363篇 |
2019年 | 491篇 |
2018年 | 700篇 |
2017年 | 772篇 |
2016年 | 716篇 |
2015年 | 430篇 |
2014年 | 576篇 |
2013年 | 4230篇 |
2012年 | 563篇 |
2011年 | 630篇 |
2010年 | 481篇 |
2009年 | 457篇 |
2008年 | 519篇 |
2007年 | 500篇 |
2006年 | 441篇 |
2005年 | 385篇 |
2004年 | 364篇 |
2003年 | 327篇 |
2002年 | 378篇 |
2001年 | 424篇 |
2000年 | 396篇 |
1999年 | 402篇 |
1998年 | 210篇 |
1997年 | 230篇 |
1996年 | 254篇 |
1995年 | 213篇 |
1994年 | 210篇 |
1993年 | 193篇 |
1992年 | 302篇 |
1991年 | 300篇 |
1990年 | 329篇 |
1989年 | 311篇 |
1988年 | 295篇 |
1987年 | 248篇 |
1986年 | 256篇 |
1985年 | 322篇 |
1984年 | 266篇 |
1983年 | 255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 15 毫秒
51.
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
52.
53.
"Change" is a critical dimension of contemporary experience. Library associations are not exempt, and they change in ways similar to other organizations. According to some authorities, four phases typify the process: diagnosis, design, implementation, and incorporation. Focusing on changes in the Medical Library Association's longstanding program of continuing education, the authors utilize the "phase framework" to chart that association's movement from a management system depending primarily upon volunteers to one in which professional staff figure prominently. The historical review serves a heuristic purpose for individuals and institutions in identifying characteristic features of the change process. 相似文献
54.
A M Pathan 《Bulletin of the Medical Library Association》1972,60(3):492-493
55.
56.
Time series analysis was used to investigate the hypothesis that during acquisition of a motor skill, knowledge of results (KR) information is used to generate a stable internal referent about which response errors are randomly distributed. Sixteen subjects completed 50 acquisition trials of each of three movements whose spatial-temporal characteristics differed. Acquisition trials were either blocked, with each movement being presented in series, or randomized, with the presentation of movements occurring in random order. Analysis of movement time data indicated the contextual interference effect reported in previous studies was replicated in the present experiment. Time series analysis of the acquisition trial data revealed the majority of individual subject response patterns during blocked trials were best described by a model with a temporarily stationary, internal reference of the criterion and systematic, trial-to-trial variation of response errors. During random trial conditions, response patterns were usually best described by a "White-noise" model. This model predicts a permanently stationary, internal reference associated with randomly distributed response errors that are unaffected by KR information. These results are not consistent with previous work using time series analysis to describe motor behavior (Spray & Newell, 1986). 相似文献
57.
The American Hospital Association (AHA) Resource Center indexes journals for the Health Planning and Administration (HEALTH) database and Hospital Literature Index (HLI). These journals, designated special list health journals, are selected to provide access to a wide and balanced coverage of hospital and health care administration and health policy literature. This article provides background information on HEALTH and HLI and describes special list health journals in detail (including historical information, information sources, and broad subject divisions). It also discusses AHA policies relating to journal and article selection and current subject distribution of special list health journals. 相似文献
58.
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
59.
Tseng SC Arcand JL Brugger JM Finn M Olson AJ Somers S 《Library resources & technical services》1990,34(2):139-157
Serials, one of the more complicated areas of library technical endeavors, has lacked the benefit of standards for a long time. Even now, with standards beginning to be available, the majority of institutions are not working within standard serials formats. A survey to determine the use of serials standards in libraries was conducted in 1988 by the American Library Association, Resources and Technical Services Division, Serials Section, Committee to Study Serials Standards. In the spring of 1988 a survey was sent to a group encompassing the Association of Research Libraries members, CONSER participants, United States Newspaper Program participants, Microform Project libraries, and some vendors and librarians who attended the Committee meetings on a regular basis. The survey questionnaire assessed the current level of serials standards awareness of librarians and vendors. Topics included the type of serials systems used, standards relevant to serials control and union listing and whether or not they are implemented, types and levels of training staff received in the application of standards, benefits of the standards, and areas where standards are most needed. 相似文献
60.
Hafner AW 《Special libraries》1990,81(4):305-308
As a gatekeeper to medical literature and a critical link in the delivery of information to physicians, the librarian's role raises the issue of the librarian's professional liability. The paper suggests several ways in which liability may attach to the librarian or the librarian's employers. Although the librarian's personal risk is negligible, the physician's exposure due to ineffective library work is substantial since the courts have held that a physician must keep abreast of progress in his field. Librarians can also become associated with professional liability actions as part of a case against a physician or hospital through the legal doctrine of vicarious liability. The paper concludes by suggesting several proactive steps for health sciences librarians to pursue to insulate themselves from professional liability and to insulate physicians and institutions from vicarious liability. 相似文献