全文获取类型
收费全文 | 22970篇 |
免费 | 361篇 |
国内免费 | 15篇 |
专业分类
教育 | 16384篇 |
科学研究 | 2033篇 |
各国文化 | 219篇 |
体育 | 1914篇 |
综合类 | 13篇 |
文化理论 | 176篇 |
信息传播 | 2607篇 |
出版年
2022年 | 180篇 |
2021年 | 262篇 |
2020年 | 382篇 |
2019年 | 605篇 |
2018年 | 829篇 |
2017年 | 805篇 |
2016年 | 700篇 |
2015年 | 424篇 |
2014年 | 658篇 |
2013年 | 4440篇 |
2012年 | 639篇 |
2011年 | 648篇 |
2010年 | 470篇 |
2009年 | 484篇 |
2008年 | 541篇 |
2007年 | 483篇 |
2006年 | 426篇 |
2005年 | 409篇 |
2004年 | 371篇 |
2003年 | 357篇 |
2002年 | 341篇 |
2001年 | 476篇 |
2000年 | 393篇 |
1999年 | 359篇 |
1998年 | 203篇 |
1997年 | 211篇 |
1996年 | 241篇 |
1995年 | 236篇 |
1994年 | 182篇 |
1993年 | 200篇 |
1992年 | 322篇 |
1991年 | 298篇 |
1990年 | 300篇 |
1989年 | 299篇 |
1988年 | 255篇 |
1987年 | 301篇 |
1986年 | 266篇 |
1985年 | 304篇 |
1984年 | 246篇 |
1983年 | 211篇 |
1982年 | 190篇 |
1981年 | 163篇 |
1980年 | 153篇 |
1979年 | 258篇 |
1978年 | 182篇 |
1977年 | 168篇 |
1976年 | 153篇 |
1975年 | 141篇 |
1974年 | 147篇 |
1971年 | 140篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
941.
Twin births are increasing at a rapid rate, yet many educational personnel throughout the world are unaware of the needs of twins in school. Stereotypical views of twins as pathologically close or excessively dependent pervade educational policies and practices, despite the fact that twins do not differ from singletons on rates of psychological disturbance. Research shows that many schools implement strict policies for classroom placement of twins, yet the effects of such policies on twins' development and educational attainment are currently unknown. Recommendations for school personnel and future directions for this formative area are discussed. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 429–438, 2003. 相似文献
942.
943.
944.
945.
946.
N. M. Builova E. M. Epshtein V. G. Shamaev 《Scientific and Technical Information Processing》2008,35(1):28-29
The necessity for publishing a separate abstract journal on spintronics, which is a new, rapidly developing branch of physics, is substantiated. The interest in spintronics, which is the study of fundamental processes involving the simultaneous transport of both electron charge and electron spins in solids, as well as the interaction of electrons with a magnetic grating, is determined not only by its fascinating prospects but also the results that have already achieved. The spin and charge “degrees of freedom” open possibilities for the creation of semiconducting devices with parameters that are much superior to the existing ones and also the construction of devices that do not have analogues at present. First of all, this will permit problems of information transmission and processing to be solved in a new way. A detailed rubrication on spintronics is given in order to discuss the possibility of publishing a separate edition of an abstract journal devoted to spintronics. 相似文献
947.
U. Casellato F. Fenzi P. Guerriero S. Sitran P. A. Vigato U. Russo M. Galgani M. Mendera A. Manasse 《Journal of Cultural Heritage》2003,4(4):337-353
A significant number of archaeological finds of the 13th–16th century from the Tuscan sites of Germagnana and Gambassi in Valdelsa—FI, was studied by different physico-chemical investigations (SEM–EDS, ICP, Mössbauer spectroscopy, XRD, XRF, TG-DTA) in order to contribute to clarify the production methodology and the pre-industrial glass manufacture technology. The studied samples are mainly non-vitreous finds as production waste, refractory materials, crucibles and raw materials; also vitreous finds as frits, skims, glasses (glass masses, glass working waste and finished products) have been taken into consideration. The obtained petrographic and physico-chemical data strongly suggest that both Gambassi and Germagnana glass manufactures were strictly connected with the sources of vitrifiable materials, situated in Tuscan sand quarries. In particular a comparison between sands from the neighbouring quarries and appropriate finds of the two archaeological sites evidences that the employed vitrifiable materials possibly belong to La Casina La Cava resort. The archaeological classification, based on macroscopic observation and stratigraphic position, was compared and verified with the scientific classification of the examined finds of Germagnana and Gambassi sites based on their composition, morphology and physico-chemical properties. 相似文献
948.
949.
950.
The Infant Characteristics Questionnaire (ICQ) was developed as a short, factor-analytic screening device for difficultness. Responses of 322 mothers of 4-6-month-old infants suggested that they regard the fussy, hard-to-soothe, labile infant as difficult. Mother report on the ICQ, particularly on the main fussy-difficult factor was found to have adequate reliability over time and convergence with the Carey Survey of Temperamental Characteristics, with father report on the ICQ, and, to a lower degree, with home data collected by independent observers. It was also found that mother characteristics may affect perceptions of infant difficultness: multiparous, extraverted mothers tended to rate their infants as easy. 相似文献