全文获取类型
收费全文 | 33788篇 |
免费 | 1230篇 |
国内免费 | 16篇 |
专业分类
35034篇 |
出版年
2020年 | 413篇 |
2019年 | 453篇 |
2018年 | 633篇 |
2017年 | 653篇 |
2016年 | 713篇 |
2015年 | 457篇 |
2014年 | 612篇 |
2013年 | 2893篇 |
2012年 | 1129篇 |
2011年 | 1161篇 |
2010年 | 789篇 |
2009年 | 780篇 |
2008年 | 1102篇 |
2007年 | 1071篇 |
2006年 | 976篇 |
2005年 | 858篇 |
2004年 | 887篇 |
2003年 | 805篇 |
2002年 | 842篇 |
2001年 | 898篇 |
2000年 | 931篇 |
1999年 | 730篇 |
1998年 | 434篇 |
1997年 | 365篇 |
1994年 | 333篇 |
1993年 | 327篇 |
1992年 | 570篇 |
1991年 | 514篇 |
1990年 | 546篇 |
1989年 | 517篇 |
1988年 | 505篇 |
1987年 | 502篇 |
1986年 | 486篇 |
1985年 | 519篇 |
1984年 | 448篇 |
1983年 | 389篇 |
1982年 | 348篇 |
1981年 | 321篇 |
1979年 | 484篇 |
1978年 | 378篇 |
1977年 | 336篇 |
1975年 | 401篇 |
1974年 | 445篇 |
1973年 | 405篇 |
1972年 | 363篇 |
1971年 | 324篇 |
1969年 | 338篇 |
1968年 | 375篇 |
1967年 | 331篇 |
1966年 | 329篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Hindsight bias was studied in the context of the accident in the Chernobyl nuclear power plant, which took place on April 26th 1986. An individual difference factor which relates to the motivation to process information, need for cognition, was expected to moderate the occurrence of hindsight bias. Probability estimates of many casualties due to the use of nuclear power in The Netherlands were obtained from 212 individuals two months before the accident in Chernobyl. These estimates were compared with similar estimates made in hindsight by the same individuals five months after the accident. Loglinear Analyses reveal a systematic hindsight bias. However, the direction of the bias was contrary to expectations. In hindsight, individuals gave lower probabilities than they actually did two months before the Chernobyl accident. These results reveal a reverse hindsight bias. As hypothesized, need for cognition moderates hindsight bias: individuals low and medium in need for cognition express a systematic reverse hindsight bias, while individuals high in need for cognition do not. High need for cognition individuals also show higher literal consistency between the two measurements, which supports a memory explanation of the moderating effect of need for cognition. 相似文献
102.
103.
104.
105.
This paper describes an amplifier for an electroencephalograph with gain of 1×104 to 1×106 and made entirely of commercially available IC components. The two-stage amplifier has a preamplifier stage with fixed gain of 1000, and a second stage with variable gain from 1 to 100. The final stage, an anti-aliasing filter, adds a gain of 10 to the signal. The circuit has high common mode rejection, low input bias current, very low noise characteristics, low offset voltages, and offset nulling capability built into the circuit. 相似文献
106.
A unique relationship exists between physicians and philosophers — one that expands on the constructive potential of the liaison between physicians and, for example, theologians, on the one hand, or, social workers on the other. This liaison should focus in the scientific aspects of medicine, not just the ethical aspects. Philosophers can provide physicians with a perspective on both the philosophy and the history of medicine through the ages — a sense of how medicine has adapted to the social cultural and ethical needs of each period. This perspective, while emphasizing medicine asscience, should not be limited to matters of methodology, or to criteria for distinguishing science from other intellectual pursuits, but should be concerned also with the history, sociology and politics of science. Both physicians and philosophers stand to gain from a strengthening of their active liaison now as never before; but most of all, the public will be the beneficiary. 相似文献
107.
Fear of Success (FOS) was originally conceived as a unidimensional motive. However, there is both theoretical and empirical
support for the hypothesis that FOS is multidimensional. We factor analyzed the responses of 236 undergraduates to twenty-oneConcern Over the Negative Consequences of Success items and found four factors. Our four factors show considerable overlap with dimensions based on theoretical accounts of
FOS etiology as well as with the factor structures obtained from two other factor analytic studies. Thus, there is converging
evidence that FOS is multidimensional. The relationship between multidimensional FOS and a multidimensional approach to achievement
motivation is discussed. 相似文献
108.
G Chastain 《Acta psychologica》1992,79(2):101-114
The role of lateral masking in more rapid performance improvement with peripheral than with central precuing was investigated. A peripheral precue to the inside of the target location provided less masking at zero precue-target delay than a precue to the outside (experiment 1) or a precue involving a partial target at the target location (experiment 2). There was no significant interaction between precue-target delay and precue type in a comparison of inside precues and precues involving a briefly-brightened box around the target location, although overall performance was significantly poorer with the latter (experiment 3). Performance was better at short precue-target delays with inside precues than with central precues (experiment 4), yet it did not improve significantly more rapidly. Minimizing lateral masking with peripheral precues thus eliminates the dramatic performance improvement sometimes observed across short precue-target delays, causing performance to be consistently better than with central precues across these delays. 相似文献
109.
Our goal was to test whether current hemisphere predominance is a predictor of scores on standardized measures of personal optimism and preference for risk. In two between-subject experiments, current hemisphere predominance was measured by the direction and extent of line bisecting errors. Pearson correlations and median splits of the line bisecting errors showed significantly greater personal optimism and preference for risk with left hemisphere predominance. These results support previous research in which manipulation of hemisphere predominance produced similar effects on personal optimism in normal individuals and on risk taking in lesioned and normal samples. We conclude that the association of optimism and risk with left hemisphere predominance can be observed in resting as well as in manipulated situations. 相似文献
110.