全文获取类型
收费全文 | 2021篇 |
免费 | 21篇 |
国内免费 | 4篇 |
专业分类
教育 | 1489篇 |
科学研究 | 181篇 |
各国文化 | 21篇 |
体育 | 165篇 |
综合类 | 12篇 |
文化理论 | 38篇 |
信息传播 | 140篇 |
出版年
2023年 | 5篇 |
2022年 | 20篇 |
2021年 | 45篇 |
2020年 | 53篇 |
2019年 | 93篇 |
2018年 | 121篇 |
2017年 | 119篇 |
2016年 | 86篇 |
2015年 | 61篇 |
2014年 | 72篇 |
2013年 | 320篇 |
2012年 | 69篇 |
2011年 | 58篇 |
2010年 | 68篇 |
2009年 | 44篇 |
2008年 | 49篇 |
2007年 | 49篇 |
2006年 | 43篇 |
2005年 | 72篇 |
2004年 | 74篇 |
2003年 | 96篇 |
2002年 | 72篇 |
2001年 | 65篇 |
2000年 | 37篇 |
1999年 | 22篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 16篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 12篇 |
1990年 | 7篇 |
1989年 | 13篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1975年 | 4篇 |
1974年 | 8篇 |
1973年 | 4篇 |
1967年 | 4篇 |
1966年 | 6篇 |
1963年 | 6篇 |
排序方式: 共有2046条查询结果,搜索用时 439 毫秒
111.
Efficient lysis is critical when analyzing single cells in microfluidic droplets, but existing methods utilize detergents that can interfere with the assays to be performed. We demonstrate robust cell lysis without the use of detergents or other chemicals. In our method, cells are exposed to electric field immediately before encapsulation in droplets, resulting in cell lysis. We characterize lysis efficiency as a function of control parameters and demonstrate compatibility with enzymatic assays by measuring the catalysis of β-glucosidase, an important cellulase used in the conversion of biomass to biofuel. Our method enables assays in microfluidic droplets that are incompatible with detergents. 相似文献
112.
113.
Trusting Virtual Trust 总被引:2,自引:0,他引:2
Can trust evolve on the Internet between virtual strangers? Recently, Pettit answered this question in the negative. Focusing on trust in the sense of ‘dynamic, interactive, and trusting’ reliance on other people, he distinguishes between two forms of trust: primary trust rests on the belief that the other is trustworthy, while the more subtle secondary kind of trust is premised on the belief that the other cherishes one’s esteem, and will, therefore, reply to an act of trust in kind (‘trust-responsiveness’). Based on this theory Pettit argues that trust between virtual strangers is impossible: they lack all evidence about one another, which prevents the imputation of trustworthiness and renders the reliance on trust-responsiveness ridiculous. I argue that this argument is flawed, both empirically and theoretically. In several virtual communities amazing acts of trust between pure virtuals have been observed. I propose that these can be explained as follows. On the one hand, social cues, reputation, reliance on third parties, and participation in (quasi-) institutions allow imputing trustworthiness to varying degrees. On the other, precisely trust-responsiveness is also relied upon, as a necessary supplement to primary trust. In virtual markets, esteem as a fair trader is coveted while it contributes to building up one’s reputation. In task groups, a hyperactive style of action may be adopted which amounts to assuming (not: inferring) trust. Trustors expect that their virtual co-workers will reply in kind while such an approach is to be considered the most appropriate in cyberspace. In non-task groups, finally, members often display intimacies while they are confident someone else ‘out there’ will return them. This is facilitated by the one-to-many, asynchronous mode of communication within mailing lists. 相似文献
114.
This essay is concerned with organisational learning and, in particular, policy learning. Sometimes, organisations learn; sometimes they do not. Sometimes they use their acquired knowledge, but this is, not always the case. 相似文献
115.
Not all young children benefit from book exposure in preschool age. It is claimed that the ability to hold information in
mind (short-term memory), to ignore distraction (inhibition), and to focus attention and stay focused (sustained attention) may have a moderating effect on children’s reactions to the home literacy environment. In a group of 228 junior kindergarten
children with a native Dutch background, with a mean age of 54.29 months (SD = 2.12 months), we explored therefore the relationship
between book exposure, cognitive control and early literacy skills. Parents filled in a HLE questionnaire (book sharing frequency
and an author recognition checklist as indicator of parental leisure reading habits), and children completed several tests
in individual sessions with the researcher (a book-cover recognition test, PPVT, letter knowledge test, the subtests categories
and patterns of the SON, and cognitive control measures namely digit span of the KABC, a peg tapping task and sustained attention
of the ANT). Main findings were: (1) Children’s storybook knowledge mediated the relationship between home literacy environment
and literacy skills. (2) Both vocabulary and letter knowledge were predicted by book exposure. (3) Short-term memory predicted
vocabulary over and above book exposure. (4) None of the cognitive control mechanisms moderated the beneficial effects of
book exposure. 相似文献
116.
The present study aimed at investigating the process of scaffolding in a naturalistic setting with focus on a key aspect of scaffolding, namely contingency. Three Social Studies teachers in innovative prevocational schools were observed and interviewed. A coding scheme for the measurement of scaffolding was developed which revealed different patterns of contingent and non-contingent teaching amongst the teachers. In general these teachers of innovative schools showed little contingent teaching. Not adapting the support to students' current understanding and barely diagnosing the students' understanding appeared to be characteristic of this scarcity of non-contingent teaching. 相似文献
117.
Understanding the association between future time perspective and self-regulated learning through the lens of self-determination theory 总被引:1,自引:0,他引:1
The present cross-sectional research examined a process underlying the positive association between holding an extended future time perspective (FTP) and learning outcomes through the lens of self-determination theory. High school students and university students (N = 275) participated in the study. It was found that students with an extended FTP regulated their study behaviour on the basis of several internal motives, including feelings of guilt and shame (introjected regulation), personal conviction (identified regulation) and interest (intrinsic motivation). The association with identified regulation was strongest and the association with intrinsic motivation fell below significance when controlling for identified regulation. Moreover, introjected and identified regulation emerged as mediators accounting for the association between FTP and cognitive processing. Further, to the extent that FTP engenders an internally pressuring mode of regulation it was found to be indirectly negatively associated with determination/metacognitive strategy use. In contrast to FTP, a present fatalistic and present hedonic time-orientation yielded more negative motivational and learning correlates. The link between FTP and self-determination theory is discussed. 相似文献
118.
Through comparative statistical data of public investment trends in higher education, the institution of higher education in the US is contemporarily contextualized within the growing milieu of disparity. Specifically, this study focuses on the period from 1992 to 2007 to see if a mitigation of the growing economic disparity projected per the Kuznets curve was reflected in the prioritization of higher education support needed to preserve the social mobility of the workforce. Through the analysis of higher educational expenditure within the budgetary priorities of the 50 states from 1992 to roughly the present, this paper reveals that, in absolute terms or by disproportional emphasis, the institutional repositioning of higher education necessary for a Kuznets curve readjustment of disparity has not occurred. 相似文献
119.
Cuijpers P Smit F Unger F Stikkelbroek Y Ten Have M de Graaf R 《Child abuse & neglect》2011,35(11):937-945
Objectives
There is much evidence showing that childhood adversities have considerable effects on the mental and physical health of adults. It could be assumed therefore, that the disease burden of childhood adversities is high. It has not yet been examined, however, whether this is true.Method
We used data of a large representative sample (N = 7,076) of the general population in the Netherlands. We calculated the disability weight (DW) for each respondent. The DW is a weight factor that reflects the severity of a disease or condition on a scale from 0 (perfect health) to 1 (equivalent to death). We used an algorithm based on the SF-6D to estimate DW. Because the DW indicates the proportion of a healthy life year that is reduced by the specific health state of the individual, it also possible to calculate the total number of years lost due to disability (YLD) in the population. We calculated the years lived with disability (YLD) for 9 different childhood adversities (in the areas of parental psychopathology; abuse and neglect; major life events), as well as for major categories of mental disorders and general medical disorders.Results
All 9 adversities resulted in a significantly increased DW, except death of a parent before the age of 16. Adversities in the category of abuse and neglect are associated with the highest DWs (0.057), followed by parental psychopathology (0.031) and life events during childhood (0.012). All adversities (46.4% of the population reports one or more adversity) are associated with 20.7 YLD/1,000, which is more than all mental disorders together (12.9 YLD/1,000). The category of abuse/neglect has the highest YLD/1,000 (15.8), which is also higher than all mental disorders together. Adjustment for the presence of mental and general medical disorders resulted in comparable outcomes.Conclusions
Childhood adversities are more important from a public health point of view than all common mental disorders together, and should be a priority for public health interventions. 相似文献120.