全文获取类型
收费全文 | 12671篇 |
免费 | 447篇 |
国内免费 | 4篇 |
出版年
2020年 | 184篇 |
2019年 | 220篇 |
2018年 | 309篇 |
2017年 | 331篇 |
2016年 | 350篇 |
2015年 | 233篇 |
2014年 | 289篇 |
2013年 | 1260篇 |
2012年 | 470篇 |
2011年 | 437篇 |
2010年 | 315篇 |
2009年 | 319篇 |
2008年 | 418篇 |
2007年 | 408篇 |
2006年 | 373篇 |
2005年 | 338篇 |
2004年 | 338篇 |
2003年 | 304篇 |
2002年 | 344篇 |
2001年 | 234篇 |
2000年 | 196篇 |
1999年 | 206篇 |
1998年 | 170篇 |
1997年 | 160篇 |
1996年 | 149篇 |
1995年 | 164篇 |
1994年 | 139篇 |
1993年 | 150篇 |
1992年 | 164篇 |
1991年 | 168篇 |
1990年 | 149篇 |
1989年 | 138篇 |
1988年 | 129篇 |
1987年 | 122篇 |
1986年 | 119篇 |
1985年 | 143篇 |
1984年 | 162篇 |
1983年 | 164篇 |
1982年 | 165篇 |
1981年 | 179篇 |
1980年 | 137篇 |
1979年 | 177篇 |
1978年 | 180篇 |
1977年 | 168篇 |
1976年 | 145篇 |
1975年 | 167篇 |
1974年 | 164篇 |
1973年 | 121篇 |
1972年 | 112篇 |
1967年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
241.
Rick M. Gardner Russell Urrutia James Morrell Deborah Watson Susan Sandoval 《Cognitive development》1990,5(4)
Body size estimates of 69 children aged 5–13 years were obtained using a TV video methodology. Tasks included an adjustment procedure where children manipulated the width of their body image on a TV, and a discrete task, where they judged the accuracy of their TV image which was presented as either normal or distorted, that is, too wide or too thin. On the continuous task, judgments were more accurate on ascending trials where children had to increase the width of the image. On the discrete task, a signal detection analysis revealed older children were better in detecting size distortion in their images and that the differences were due to differences in the biological sensory system and not due to a bias to report that they were too fat or too thin. However, there were response bias differences between genders. Females were more likely to report size distortion with increasing age while males were less likely. 相似文献
242.
Sons of male alcoholics are at particularly heightened risk for the development of alcoholism. This heightened risk frequently appears in association with increased incidence of conduct disorder or hyperactivity, with deficits in abstract thinking and poor school performance, with abnormalities in cued psychophysiological response, and with increased sensitivity to the putatively stress-response-dampening effects of alcohol intoxication. This risk and its associated features are discussed within the context of a neuropsychological theory, predicated on the notions (1) that deficits in cognitive functions theoretically dependent upon the intact functioning of the prefrontal cortex could underlie manifestation of the idiosyncracies commonly attributed to sons of male alcoholics, and (2) that acute alcohol intoxication could relieve the subjective discomfort associated with the consequences of such deficits. 相似文献
243.
Edward O. Wilson 《Zygon》1990,25(3):245-262
Abstract. The sciences may be conceptualized as a hierarchy ranked by level of organization (e.g., many-body physics ranks above particle physics). Each science serves as an antidiscipline for the science above it; that is, between each pair, tense but creative interplay is inevitable. Biology has advanced through such tension between its subdisciplines and now can serve as an antidiscipline for the social sciences—for anthropology, for example, by examining the connection between cultural and biological evolution; for psychology, by addressing the nature of learning and the structure of the unconscious; for economics, by examining economically irrational behavior and by comparing economic activity in humans and other species. Sociology, concerned mainly with advanced literate societies, is relatively remote from the genetic basis of human social behavior. However, moving between biological and social levels of organization generates richness and points to new and unexpected principles. 相似文献
244.
Teaching the Use of Cost-Benefit Reasoning in Everyday Life 总被引:1,自引:0,他引:1
245.
246.
A survey of Human Resource practitioners' perceptions of pre-employment screening procedures was conducted. The results indicated differences between tests in terms of perceived accuracy and offensiveness, as well as other attributes. Regression analyses suggested that beliefs about validity, the number of other companies using these procedures, perceived offensiveness of the test, and ease in passing the test were important factors in the willingness to use a particular test. Conversely, perceptions regarding the discriminatory impact of the test and the cost of using the test generally were not related to willingness to use the test. Limitations of this study, which was primarily exploratory, are noted. 相似文献
247.
Michael D. Gliksman M.P.H. F.A.C.O.M. Allan Kellehear Ph.D. 《Journal of Near-Death Studies》1990,9(1):41-43
Although cerebral anoxia is not thought to be responsible for triggering near-death experiences (NDEs), the issue is not so clear in the case of hypercapnia. Detection of normal blood gases in Michael Sabom's (1982) case study seems to be the major reply to suggestions that hypercapnia may have a causal role in NDEs. We argue, however, that routine arterial measures of blood gases are not a reliable indicator of cerebral levels. 相似文献
248.
In this paper, we describe software that turns a Macintosh computer into an off-the-shelf tool for experiments on visual search. Our design goals included portability (between members of the Macintosh computer family and between various research settings), user-friendliness (equivalent to Macintosh programming standards), flexibility (to allow replication and extension of important experiments on visual search), and adaptability (very short design-to-data and data-to-analysis turnaround times). We describe how the software meets these goals in three major phases of an experiment: stimulus construction, experimental control, and statistical analysis. We then list several landmark studies of visual search that can be easily designed and extended with the software. Finally, we outline plans for expanding the experimental variations that will be supported in future versions of the software. 相似文献
249.
Thomas G. Fikes Roberta L. Klatzky James Pellegrino Chick Hebert Larry Murdoch 《Behavior research methods》1990,22(3):290-296
In this paper, we describe an apparatus for measuring reaction times and movement times involved in reaching for real objects. Subjects view an object through a liquid crystal window, which serves as a shutter that can be made clear or opaque quickly (10 msec from opaque to clear, 30 msec from clear to opaque). The subject’s hand rests on a microswitch-equipped home key, and the object sits on a force-sensitive platform so that initiation of reach and time of contact with the object can be marked accurately. The apparatus interfaces with an IBM PC/AT through a digital I/O parallel port, so that reaction times and movement times are recorded automatically. 相似文献
250.
Hardware is described that permits bidirectional transfer of data between the Commodore 64 and an IBM-compatible PC. Commercial terminal programs can be used to transmit data. The hardware, which can be constructed for less than $15, opens up several opportunities for making good use of the cost-effective C64 computer. 相似文献