全文获取类型
收费全文 | 30859篇 |
免费 | 1080篇 |
国内免费 | 12篇 |
出版年
2020年 | 336篇 |
2019年 | 347篇 |
2018年 | 437篇 |
2017年 | 474篇 |
2016年 | 566篇 |
2015年 | 424篇 |
2014年 | 436篇 |
2013年 | 2400篇 |
2012年 | 866篇 |
2011年 | 941篇 |
2010年 | 579篇 |
2009年 | 620篇 |
2008年 | 820篇 |
2007年 | 807篇 |
2006年 | 684篇 |
2005年 | 676篇 |
2004年 | 653篇 |
2003年 | 659篇 |
2002年 | 653篇 |
2001年 | 787篇 |
2000年 | 767篇 |
1999年 | 562篇 |
1998年 | 343篇 |
1997年 | 309篇 |
1992年 | 532篇 |
1991年 | 490篇 |
1990年 | 503篇 |
1989年 | 484篇 |
1988年 | 431篇 |
1987年 | 452篇 |
1986年 | 480篇 |
1985年 | 512篇 |
1984年 | 441篇 |
1983年 | 421篇 |
1982年 | 304篇 |
1981年 | 342篇 |
1979年 | 473篇 |
1978年 | 355篇 |
1977年 | 308篇 |
1976年 | 298篇 |
1975年 | 417篇 |
1974年 | 469篇 |
1973年 | 497篇 |
1972年 | 420篇 |
1971年 | 409篇 |
1970年 | 378篇 |
1969年 | 404篇 |
1968年 | 499篇 |
1967年 | 479篇 |
1966年 | 455篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
951.
This paper evaluates three hypotheses about the structure of threat perceptions in the post-Cold War era: the replacement of a military conception of threat by an economic one; fluidity in threat perceptions because of an absence of a polestar nation; and Huntington's clash of civilizations theory. Using psychophysical magnitude measures of threat perception, these findings provide no support for the notion that threats are perceived economically. There is limited support for the theory that threat perceptions are unstable; most countries are clustered around a core of weakly hostile or friendly perceptions, which is suggestive of instability. At the same time, however, there does appear to be stability in perceptions of strong friends and enemies. The hypothesis best supported by these data is Huntington's theory that culture determines threat perceptions. In this study, not a single Western country is perceived as hostile, and all nations that do receive hostile scores are non-Western. 相似文献
952.
Linda C. Mayes Ruth Feldman Richard H. Granger O.Maurice Haynes Marc H. Bornstein Richard Schottenfeld 《Infant behavior & development》1997,20(4):578
The face-to-face interactions of 43 polydrug-with-cocaine-using mothers and their infants at 3 and 6 months were compared to 17 non-cocaine-but other-drug-using mothers and 21 mothers who used no drugs during their pregnancy. Coders blind to mothers' drug use status scored 3 min of face-to-face interactions for 16 measures of maternal and infant interactive behaviors. A principal component of 7 behaviors formed a measure of maternal attentiveness; a principal component of 5 behaviors formed a measure of mother-infant dyadic organization; and a principal component of 4 behaviors formed a measure of infant readiness to interact. A measure of maternal interruption was computed as the mean standard score of 3 additional interruptive behaviors. At 3 and 6 months, polydrug-with-cocaine-using mothers were less attentive to interactions, and polydrug-with-cocaine-using mothers and their infants engaged in fewer dyadic interactions than either non-cocaine or non-drug-using mothers. Compared to 3 months, polydrug-with-cocaine-using mothers at 6 months were less attentive to interactions and more frequently interrupted interactions by looking away, redirecting the infant, or withdrawing, whereas non-cocaine-using and non-drug- using mothers showed no change or an improvement in attentiveness to interactions and a decrease in interruptions. No differences emerged in the interactive behaviors of the infants of polydrug- with-cocaine-using, non-cocaine-using, or non-drug-using mothers. Cocaine use represents a significant risk for diminished parental attentiveness and responsiveness to infants and for diminished interactiveness in infants. 相似文献
953.
954.
When procedural artifacts are controlled, it has been difficult to demonstrate directed forgetting in pigeons. However, previous research with pigeons has not allowed for the reallocation of working memory (from forget items to remember items) on forget-cued trials as is possible in human directed forgetting experiments. In the present experiment, directed forgetting was found while controlling for procedural artifacts and allowing the pigeons to reallocate memory resources on forget trials. The results indicate that under these conditions, pigeons have active control over memory processing. 相似文献
955.
John E. Carr G. Andrew H. Benjamin 《Journal of clinical psychology in medical settings》1997,4(2):143-153
Health care reform has put increasing pressure on faculty of medical schools to become self-supporting. Opportunities for clinical revenue will decrease, but psychologists who are able to generate research funding will become increasingly competitive, albeit as mercenaries, i.e., capable of paying their own way plus generating a profit to support departmental operations and educational programs. Changes in the health care system signal an end to psychiatry's paternalistic relationship to psychology and present opportunities for psychology proactively to influence its future role in health care. Research, political action, and revised scientific mission, models, and roles represent important strategies in the redefining of psychology as a basic science and major profession in health care. 相似文献
956.
957.
958.
Mark Fox 《Journal of Beliefs & Values》1997,18(2):169-179
This article argues that currently many aspects of the Near Death Experience (NDE) remain a mystery, even after the more than two decades of discussion and analysis triggered by the publication of Raymond Moody's ground‐breaking study, Life After Life in 1975. It suggests that one reason for this continuing mystery is connected to the current under‐representation of studies of the phenomenon from within philosophy generally, and philosophy of religion in particular. It questions why this under‐representation should exist, suggesting that the very complexity of the NDE demands a thoroughgoing philosophical analysis, and arguing that philosophy and philosophy of religion have a crucial and rightful role alongside other disciplines within any attempt to gain a total understanding of what NDEs, in essence, are. 相似文献
959.
Neural structures involved in aggression were incorporated into a model on the basis of neuro-anatomical data. A software program written in Smalltalk, the Brain Structure Simulator (Seguin, 1994) was used to simulate the effects of activity levels of different brain structures. Relationships among brain structures were then tested by changing activity levels of key structures. Results were consistent with research reports on the brain basis of aggression (Albert, Walsh, & Jonik, 1993; Pontius, 1984). 相似文献
960.
Theoretical Medicine and Bioethics - 相似文献