全文获取类型
收费全文 | 38713篇 |
免费 | 1410篇 |
国内免费 | 25篇 |
专业分类
40148篇 |
出版年
2020年 | 439篇 |
2019年 | 494篇 |
2018年 | 638篇 |
2017年 | 671篇 |
2016年 | 742篇 |
2015年 | 556篇 |
2014年 | 661篇 |
2013年 | 3291篇 |
2012年 | 1200篇 |
2011年 | 1262篇 |
2010年 | 782篇 |
2009年 | 818篇 |
2008年 | 1130篇 |
2007年 | 1083篇 |
2006年 | 1026篇 |
2005年 | 959篇 |
2004年 | 902篇 |
2003年 | 923篇 |
2002年 | 937篇 |
2001年 | 922篇 |
2000年 | 881篇 |
1999年 | 676篇 |
1998年 | 427篇 |
1997年 | 428篇 |
1996年 | 393篇 |
1992年 | 598篇 |
1991年 | 603篇 |
1990年 | 587篇 |
1989年 | 567篇 |
1988年 | 489篇 |
1987年 | 529篇 |
1986年 | 565篇 |
1985年 | 628篇 |
1984年 | 551篇 |
1983年 | 503篇 |
1982年 | 394篇 |
1981年 | 444篇 |
1979年 | 538篇 |
1978年 | 426篇 |
1977年 | 389篇 |
1975年 | 492篇 |
1974年 | 557篇 |
1973年 | 559篇 |
1972年 | 458篇 |
1971年 | 447篇 |
1970年 | 409篇 |
1969年 | 433篇 |
1968年 | 516篇 |
1967年 | 501篇 |
1966年 | 481篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
Sources of difficulty in deductive reasoning: The THOG task 总被引:2,自引:0,他引:2
David P. O'Brien Ira A. Noveck George M. Davidson Shalom M. Fisch R. Brooke Lea Jason Freitag 《The Quarterly Journal of Experimental Psychology Section A: Human Experimental Psychology》1990,42(2):329-351
The THOG task presents four designs constructed from two shapes and two colours. Subjects are told that the experimenter has written down one of the shapes and one of the colours and are provided the rule that if, and only if, any design has either the shape or the colour, but not both, written down, then it is a THOG. Finally, they are given an exemplar and are asked to classify the remaining designs. Successful solution requires construction of hypotheses, reasoning under each hypothesis, and comparison of the results under each to reach a final conclusion. Few subjects are able to provide adequate responses on the standard version of the task. We present the results of four experiments, with 160 undergraduates each presented with one of eight versions of the task. Experiments 1 and 2 indicate that (1) some subjects think that the properties that are written down are identical to those of the exemplar, although these are not the same subjects who exhibit the modal error pattern, (2) many subjects correctly understand the disjunction of the rule but fail to consider the hypotheses, and (3) poor initial encoding of the problem is not easily corrected. Experiment 3 investigates the sufficiency of the claim of Griggs and Newstead (1982) that appropriate problem solution follows from explicit presentation of all problem information (including use of positive labels for properties that are not written down), and Experiment 4 investigates the necessity of the claim. The results of Experiments 3 and 4 show that presenting positive category labels does increase the frequency of correct solution; however, positive category labels are not necessary for such improvement. Separation of the labels of the THOG rule from those of the exemplar, or informing subjects that only one other design is a THOG, also increases the frequency of successful solution. The results suggest that many people have some fairly sophisticated reasoning skills. but application of these skills is easily discouraged when the features of the task lead to poor initial encoding. 相似文献
962.
D. H. Mellor 《国际科学哲学研究》1990,4(2):159-170
The paper develops a unified account of both deterministic and indeterministic laws of nature which inherits the merits but not the defects of the best existing accounts. As in Armstrong's account, laws are embodied in facts about universals; but not in higher‐order relations between them, and the necessity of laws is not primitive but results from their containing chances of 0 or 1. As in the Ramsey‐Lewis account, law statements would be the general axioms and theorems of the simplest deductive theory of everything; but because laws are not so defined, simplicity of statement is not a criterion of law‐hood. 相似文献
963.
Efficacy of behavioral management and patient education on vascular access cleansing compliance in hemodialysis patients 总被引:1,自引:0,他引:1
Compared four treatment conditions to test their ability to enhance compliance with vascular access cleansing (VAC) procedures in a group of 56 hemodialysis patients. The conditions were patient education, behavioral management with monetary incentive, patient education/behavioral management, and attention control. Behavioral observers rated VAC behavior at pretreatment, posttreatment 1-month follow-up, and 1-year follow-up. Knowledge of VAC procedures was also assessed via a questionnaire at pretreatment and posttreatment. Data were analyzed using repeated-measures multivariate analyses of variance. Results indicated that the patients in the education/behavioral, behavioral, and education groups gave significantly more correct answers on our VAC knowledge questionnaires at posttreatment than did patients in the attention control group. Further, patients in the education/behavioral and behavioral groups completed significantly more VAC steps at posttreatment and 1-month follow-up than did patients in the education group and in the attention control group. Differences were not maintained at 1-year follow-up, although more than 50% of the patients were lost to follow-up. Implications of the present findings for behavioral and educational interventions are discussed. 相似文献
964.
Summary When a line (the pointer) is collinear with a dot, the addition of a second line (the induction line) contiguous with the dot or near it may cause the pointer to appear to be collinear with a point further along or nearer to the induction line. The geometrical relations upon which this effect, which we call attraction-caused misalignment, depends have been studied with the Obonai and Wundt-Loeb (Hotopf, 1981; Hotopf & Brown, 1988) figures. Drawing upon the studies of misalignment in the Morinaga figure carried out by Restle (1976), Day, Bellamy, and Norman (1983), and Day and Kasperczyk (1985), as well as upon two new experiments, we show that misalignment in the Morinaga figure is also attraction-caused misalignment, as previously defined. We conclude with a discussion of a number of theories that aim at accounting for attraction misalignment. 相似文献
965.
Summary In the literature two different views with regard to the time course of activation of recognition units —hypothetical entities that represent identity information —are proposed. Both views are derived from a restricted set of phenomena in visual perception. The first view gets its intuitions from phenomena such as those summarized by Bloch's law; these phenomena show integration or summation of activation over time. This grow-and-grow view assumes that recognition units accumulate activation gradually over times The second view finds its inspiration in phenomena such as Mach-bands and simultaneous contrast; these phenomena show inhibition or steady-state suppression over time. This grow-and-shrink view assumes that the activation levels increase fast initially and then start to decrease.The perception literature strongly suggests that it may be light intensity that determines whether mainly integration (and phenomena such as Bloch's law) or inhibition (and phenomena such as Mach-bands) is obtained. So it is also likely that both information-processing views apply only to a limited range of intensity conditions; the grow-and-grow view to conditions of low-flight intensities, and the grow-and-shrink view to conditions of intermediate-and high-light intensities.It is argued that, to arrive at a complete view, a visual phenomenon that applies to the complete range of light intensities should be taken as a background for generating hypotheses about time courses in visual-information processing. The Broca-Sulzer effect is such a phenomenon. Starting from this phenomenon a simple, synthesizing, information-processing model is derived that is compatible with both the grow-and-grow view and the grow-andshrink view. It is shown that, besides the relevant temporal properties, this model also produces the appropriate spatial properties. 相似文献
966.
The study was part of an official project of the Women in Management Division of the Academy of Management to examine the status of research in gender issues in organizations. It specifically looked at 22 major scholarly and trade journals plus the Proceedings of the Academy of Management for the six-year period of 1983–1988 to determine quantity, patterns, and trends in publication of research on issues of interest to the domain of the division. Results show a downward trend in gender-issue publication at a time when working women are becoming an ever-increasing percentage of the work force. This is particularly true of the so-called prestige journals. Psychology journals accounted for 64% of the total, management 13.4%, personnel 19%, and Proceedings 3.5%. Implications for research and careers are discussed.A shorter, less-complete version of this paper was presented in summary form at the annual meeting of The Academy of Management in Washington, DC, August 1989 as part of a symposium for the Women in Management Division. 相似文献
967.
Visual perception and the guidance of locomotion without vision to previously seen targets 总被引:6,自引:0,他引:6
Two experiments were performed to assess the accuracy and precision with which adults perceive absolute egocentric distances to visible targets and coordinate their actions with them when walking without vision. In experiment 1 subjects stood in a large open field and attempted to judge the midpoint of self-to-target distances of between 4 and 24 m. In experiment 2 both highly practiced and unpracticed subjects stood in the same open field, viewed the same targets, and attempted to walk to them without vision or other environmental feedback under three conditions designed to assess the effects on accuracy of time-based memory decay and of walking at an unusually rapid pace. In experiment 1 the visual judgments were quite accurate and showed no systematic constant error. The small variable errors were linearly related to target distance. In experiment 2 the briskly paced walks were accurate, showing no systematic constant error, and the small, variable errors were a linear function of target distance and averaged about 8% of the target distance. Unlike Thomson's (1983) findings, there was not an abrupt increase in variable error at around 9 m, and no significant time-based effects were observed. The results demonstrate the accuracy of people's visual perception of absolute egocentric distances out to 24 m under open field conditions. The accuracy of people's walking without vision to previously seen targets shows that efferent and proprioceptive information about locomotion is closely calibrated to visually perceived distance. Sensitivity to the correlation of optical flow with efferent/proprioceptive information while walking with vision may provide the basis for this calibration when walking without vision. 相似文献
968.
Saccadic reaction times (SRT) were measured in a simple task: subjects had to make saccades from a central fixation point to peripheral targets, which appeared randomly 4 deg to the left or to the right. In the first test the fixation point went off before the target appeared (gap trials); in the second test it remained on the screen (overlap trials). The distribution of SRTs for trained normal adults (N = 4), untrained normal adults (N = 11), untrained normal children (aged 9-11 years, N = 9), untrained normal teenagers (aged 15-17 years, N = 8), dyslexic children (aged 9-11 years, N = 15), and dyslexic teenagers (aged 15-17 years, N = 5) were compared, with special emphasis on the number of express saccades, ie saccades with extremely short reaction times (100-120 ms, under the present conditions). In normal adults with the gap paradigm, the distribution of reaction times typically exhibits two or three modes (express saccades, fast regular saccades, and very few slow regular saccades), whereas in the overlap paradigm only one or two modes (few fast regular saccades and many slow regular saccades) are obtained. On average, normal children produce more express saccades than naive normal adults. Dyslexic children produce more express saccades than the normal age-matched controls. Among the dyslexic children, four different types of abnormalities in their reaction times were encountered. The group of dyslexic teenagers was characterized by a larger number of express saccades at the expense of fast regular saccades in gap trials and by fewer express saccades and fewer fast regular saccades in overlap trials when compared to the age-matched control group. It is concluded that the abnormal patterns of saccadic reaction times reflect defects in the system of visual attention and/or in its control over the oculomotor system, rather than indicating a defect in the oculomotor system itself. In this context, symptoms of dyslexia appear as a combination of attentional deficits and irregular timing of saccadic eye movements. 相似文献
969.
970.
Donald H. Wallace 《Behavioral sciences & the law》1990,8(3):249-262
Interdisciplinary training in behavioral sciences and the law should be appropriate for a criminal justice education program. However, adopting such an interdisciplinary goal is problematic because the divisions in the types of educational curricula need to be confronted. The relationships of the criminal justice academic community with the profession, and of the behavioral sciences with present criminal justice policies, must also be addressed in the attempt to develop familiarity with behavioral sciences and their legal relevance in shaping the criminal justice system. These factors may hinder extensive implementation of such training. Suggestions are made for incorporating this raining in a criminal justice curriculum. 相似文献