全文获取类型
收费全文 | 22298篇 |
免费 | 748篇 |
国内免费 | 11篇 |
专业分类
23057篇 |
出版年
2020年 | 203篇 |
2019年 | 207篇 |
2018年 | 316篇 |
2017年 | 359篇 |
2016年 | 356篇 |
2015年 | 229篇 |
2014年 | 300篇 |
2013年 | 1639篇 |
2012年 | 599篇 |
2011年 | 656篇 |
2010年 | 401篇 |
2009年 | 377篇 |
2008年 | 552篇 |
2007年 | 546篇 |
2006年 | 497篇 |
2005年 | 447篇 |
2004年 | 438篇 |
2003年 | 400篇 |
2002年 | 453篇 |
2001年 | 721篇 |
2000年 | 741篇 |
1999年 | 550篇 |
1998年 | 254篇 |
1997年 | 214篇 |
1992年 | 448篇 |
1991年 | 406篇 |
1990年 | 441篇 |
1989年 | 414篇 |
1988年 | 396篇 |
1987年 | 398篇 |
1986年 | 404篇 |
1985年 | 421篇 |
1984年 | 333篇 |
1983年 | 299篇 |
1982年 | 237篇 |
1981年 | 212篇 |
1979年 | 386篇 |
1978年 | 278篇 |
1977年 | 251篇 |
1976年 | 222篇 |
1975年 | 341篇 |
1974年 | 372篇 |
1973年 | 351篇 |
1972年 | 328篇 |
1971年 | 287篇 |
1970年 | 260篇 |
1969年 | 321篇 |
1968年 | 358篇 |
1967年 | 321篇 |
1966年 | 325篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
993.
OBJECTIVE: The premise that pessimistic health appraisals compromise well-being whereas optimistic appraisals are compensatory was examined in a longitudinal study of 232 community-dwelling older adults (ages 79-98 years). DESIGN: Subjective health (SH) appraisals were contrasted with objective health (OH) to identify realists, whose ratings were congruent (SH = OH), distinguishing them from health pessimists (SH < OH) and health optimists (SH > OH), whose ratings were incongruent. Analyses of covariance were used to examine group differences 2 years later on well-being and health care. MAIN OUTCOME MEASURES: Outcome measures were psychological well-being (life satisfaction, positive and negative emotions), functional well-being (objective and perceived physical activity, activity restriction), and health care (health care management, hospital admissions, length of hospital stays). RESULTS: Compared with realists, pessimists had significantly poorer outcomes and optimists had better outcomes. Because perceived control (PC) was weaker among pessimists and stronger among optimists, supplemental analysis determined whether PC differences explained these findings. When accounting for PC, many pessimism and optimism effects became nonsignificant, yet effects on functional well-being remained unchanged. CONCLUSION: Findings have implications for older adults at risk of functional decline. 相似文献
994.
995.
Sex-stereotyping: students' perceptions of college professors 总被引:1,自引:0,他引:1
G Babladelis 《Perceptual and motor skills》1973,37(1):47-50
996.
A cognitive model of the processes underlying the arousal of a state of communication apprehension is proposed. This model draws upon current work in cognitive science to specify the nature of the relevant structures and the nature of the processes that operate over those structures. An empirical test of the model indicates strong support in that the interaction of long-term memory contents and perceived evaluative ness of the situation was a significant predictor of anxiety. Additionally, the model allowed the prediction of changes in physiological arousal (heart rate) over time that closely paralleled observed heart rate. 相似文献
997.
998.
Moshe Naveh-Benjamin Fergus I. M. Craik James G. Perretta Simon T. Tonev 《The Quarterly Journal of Experimental Psychology Section A: Human Experimental Psychology》2000,53(3):609-625
We have recently cast doubt (Craik, Govoni, Naveh-Benjamin, & Anderson, 1996; Naveh-Benjamin, Craik, Guez, & Dori, 1998) on the view that encoding and retrieval processes in human memory are similar. Divided attention at encoding was shown to reduce memory performance significantly, whereas divided attention at retrieval affected memory performance only minimally. In this article we examined this asymmetry further by using more difficult retrieval tasks, which require substantial effort. In one experiment, subjects had to encode and retrieve lists of unfamiliar name-nouns combinations attached to people's photographs, and in the other, subjects had to encode words that were either strong or weak associates of the cues presented with them and then to retrieve those words with either intra- or extra-list cues. The results of both experiments showed that unlike division of attention at encoding, which reduces memory performance markedly, division of attention at retrieval has almost no effect on memory performance, but was accompanied by an increase in secondary-task cost. Such findings again illustrated the resiliency of retrieval processes to manipulations involving the withdrawal of attention. We contend that retrieval processes are obligatory or protected, but that they require attentional resources for their execution. 相似文献
999.
The availability of improved HIV treatments may prompt reduced concern about HIV and sexual risk. Gay and bisexual men (N = 554, 17% HIV-positive) completed measures of treatment attitudes, sexual risk, and assumptions regarding the infectiousness of sexual partners. A substantial minority reported reduced HIV concern related to treatment advances. Reduced HIV concern was an independent predictor of sexual risk, particularly among HIV-positive men. In response to hypothetical scenarios describing sex with an HIV-positive partner, participants rated the risk of unprotected sex to be lower if the partner was taking combination treatments and had an undetectable viral load, relative to scenarios with a seropositive partner not taking combination treatments. Prevention efforts must address attitudinal shifts prompted by recent treatment successes, stressing the continued importance of safer sex, and that an undetectable viral load does not eliminate infection risks. 相似文献
1000.