全文获取类型
收费全文 | 5780篇 |
免费 | 57篇 |
国内免费 | 136篇 |
专业分类
教育 | 3234篇 |
科学研究 | 1307篇 |
各国文化 | 35篇 |
体育 | 798篇 |
综合类 | 94篇 |
文化理论 | 20篇 |
信息传播 | 485篇 |
出版年
2024年 | 31篇 |
2023年 | 57篇 |
2022年 | 76篇 |
2020年 | 25篇 |
2018年 | 30篇 |
2017年 | 41篇 |
2016年 | 40篇 |
2015年 | 83篇 |
2014年 | 364篇 |
2013年 | 121篇 |
2012年 | 220篇 |
2011年 | 294篇 |
2010年 | 159篇 |
2009年 | 146篇 |
2008年 | 270篇 |
2007年 | 486篇 |
2006年 | 305篇 |
2005年 | 322篇 |
2004年 | 277篇 |
2003年 | 302篇 |
2002年 | 285篇 |
2001年 | 155篇 |
2000年 | 150篇 |
1999年 | 90篇 |
1998年 | 38篇 |
1997年 | 48篇 |
1996年 | 52篇 |
1995年 | 68篇 |
1994年 | 43篇 |
1993年 | 54篇 |
1992年 | 67篇 |
1991年 | 62篇 |
1990年 | 80篇 |
1989年 | 65篇 |
1988年 | 71篇 |
1987年 | 77篇 |
1986年 | 80篇 |
1985年 | 77篇 |
1984年 | 66篇 |
1983年 | 70篇 |
1982年 | 53篇 |
1981年 | 49篇 |
1960年 | 26篇 |
1959年 | 44篇 |
1958年 | 43篇 |
1957年 | 33篇 |
1956年 | 60篇 |
1955年 | 64篇 |
1954年 | 23篇 |
1953年 | 38篇 |
排序方式: 共有5973条查询结果,搜索用时 15 毫秒
101.
OBJECTIVE: This study compared recidivism rates for alleged maltreatment perpetrators whose initial report was substantiated and those whose initial report was not substantiated, to determine whether they returned to the child welfare system at differing rates. METHOD: Statewide administrative child welfare services data over a period of 4 1/2 years was analyzed. The sample included 31,531 perpetrators of intrafamilial maltreatment. Separate analyses were conducted for each type of maltreatment (sexual abuse, physical abuse, and neglect). RESULTS: Bivariate relationships (substantiation status and recidivism) were analyzed using survival curves, and the study found that recidivism patterns differed by type of maltreatment and by substantiation status at the index event. Multivariate analyses using Cox Proportional Hazards models found that bivariate relationships held true even when controlling for neighborhood mean income, ethnicity, and gender. CONCLUSIONS: The study's finding that perpetrators whose index event was not substantiated return to the child welfare system at a high rate suggests the need to learn how to discriminate those unsubstantiated alleged perpetrators who are most at risk for recidivism. The finding of frequent cross-type recidivism indicates that intervention should focus on common themes across maltreatment types. 相似文献
102.
103.
104.
假设有人给了你一枝笔,一枝密封的、纯色的水笔,里面有多少墨水你看不到,很可能刚刚试写几字便用干耗尽;也可能足以完成一部或几部杰作,永存于世,使世事为之大变。而这一切你在动笔之前却是一无所知。根据游戏的规则,你确实水远也不会知道,只能冒一下险。而事实上,也没有 相似文献
105.
我向空中射出一枝箭,我不知它落在何方。因为它飞得如此神速,我的视力都追赶不上。我向高空唱出一支歌,我不知它落在何方。谁有如此犀利眼力,能追赶上歌声的飞扬? 相似文献
106.
The effects of identical context on pattern recognition by pigeons for outline drawings of faces were investigated by training
pigeons to identify (Experiment 1) and categorize (Experiment 2) these stimuli according to the orientation of the mouth—an
upright U shape representing a smiling mouth or an inverted U shape representing a sad mouth. These target stimuli were presented
alone (Pair 1), with three dots in a triangular orientation to represent a nose and eyes (Pair 2), and with the face pattern
surrounded by an oval (Pair 3). In Experiment 1, the pigeons trained with Pair 1 were most accurate, those trained with Pair
2 were less so, and those trained with Pair 3 failed to acquire the discrimination within eighty 100-trial sessions. The same
ordering was found in Experiment 2 for pigeons trained on the three pairs simultaneously. The authors suggest that a contrasting
finding in humans, the face superiority effect, might be due to a gain in discriminability resulting from recognition of the
pattern as a face. An exemplar model of information processing that excludes linguistic coding accounts for the present results. 相似文献
107.
大卫.A.博曼 《课堂内外(高中版)》2007,(5):1
假如有人给你一支笔,一支密封的、纯色的水笔,里面有多少墨水你无法看到,很可能刚刚试着写几个字就能用干,也可能足够写一部或几部皇皇巨著,流传千古,使世事为之而改变。而这一切你在动笔之前无法知晓。 相似文献
108.
109.
Kinetics study on biomass pyrolysis for fuel gas production 总被引:1,自引:0,他引:1
INTRODUCTIONSincebiomassisanabundant,inexpensiveandrenewableresource ,itsconversiontosyn theticfuelsandchemicalproductsappearsat tractive.Amongallkindsofbiomassconversionroutes,pyrolysisisbeinggivenincreasingatten tionsincetheprocessissimpleandmaybeopti m… 相似文献
110.
Cultureisoneofthemostdifficulttermstobewelldefined.NewWebstersDictionarysaysitisnotonly"theacquiredabilityofanindividualorapeopletorecognizeandappreciategenerallyacceptedestheticandintellectualachievementofcivilizationoraparticularstageorstagesofcivilizationasinthecaseofacertainnationorperiod"butalso"thetotalofhumanbehaviorpatternsandtechnologycommunicatedfromgene-rationtogeneration".Thelatterisananthropologicalandsociologicaldefinition,whichagreeswithLongmanModernEnglishDictionary'sthirddef… 相似文献