全文获取类型
收费全文 | 27268篇 |
免费 | 1026篇 |
国内免费 | 14篇 |
专业分类
28308篇 |
出版年
2019年 | 305篇 |
2018年 | 468篇 |
2017年 | 469篇 |
2016年 | 489篇 |
2015年 | 377篇 |
2014年 | 420篇 |
2013年 | 2179篇 |
2012年 | 782篇 |
2011年 | 789篇 |
2010年 | 467篇 |
2009年 | 454篇 |
2008年 | 616篇 |
2007年 | 687篇 |
2006年 | 591篇 |
2005年 | 554篇 |
2004年 | 535篇 |
2003年 | 504篇 |
2002年 | 544篇 |
2001年 | 931篇 |
2000年 | 883篇 |
1999年 | 668篇 |
1998年 | 265篇 |
1996年 | 275篇 |
1995年 | 241篇 |
1992年 | 549篇 |
1991年 | 546篇 |
1990年 | 528篇 |
1989年 | 483篇 |
1988年 | 496篇 |
1987年 | 458篇 |
1986年 | 487篇 |
1985年 | 483篇 |
1984年 | 395篇 |
1983年 | 349篇 |
1982年 | 242篇 |
1981年 | 256篇 |
1979年 | 440篇 |
1978年 | 320篇 |
1977年 | 273篇 |
1976年 | 252篇 |
1975年 | 345篇 |
1974年 | 443篇 |
1973年 | 463篇 |
1972年 | 351篇 |
1971年 | 353篇 |
1970年 | 355篇 |
1969年 | 323篇 |
1968年 | 450篇 |
1967年 | 385篇 |
1966年 | 367篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
L. B. Cebik 《Theoretical medicine and bioethics》1980,1(1):67-83
Heidegger's conception of death as an attitude toward life, overlooked in current literature on death and dying, offers potential for deepening our understanding of the care of non-critically ill patients. By breaking away from the notion of death as an event distinct from life and viewing it as an anticipated possibility at every moment of life, Heidegger provides insight into our attempts to evade death through our fundamental attitudes and value commitments, which in turn determine our behavior and actions. When combined with a method of application — the Nietzschean principle of reversal — these insights permit the understanding of diverse types of human mentality confronted with significant situations. Among the most important applications of these conceptions is to persons in need of medical care, and the resultant types, which are sampled as hypothetical cases, carry important implications for the sensitive care and psychosocial management of non-terminally ill patients. 相似文献
993.
Richard B. Millward 《Behavior research methods》1980,12(2):178-192
BANDAID is an intelligent computer-assisted instruction (ICAI) system designed for students learning to program in BASIC. The major thesis is that beginning students need a friendly environment, that is, one in which information about the language and the system are immediately available. The system accepts most commands without switching levels: BASIC lines are parsed on input with very specific error messages. An editor allows corrections of BASIC lines. The program can be traced while running, and an indefinite number of HELP comments can be written for the system. Without leaving the BASIC environment, the user can interact with the CMS monitor of the main machine running the program. Although no English language comments or questions are allowed, the system is modular so that additions of restrictive dialogue interaction and guided tutoring are possible. Illustrations are presented showing the capabilities of the system. The paper also presents some of the implementation details of BANDAID. A flexible system requires implementation in LISP, so examples of how the system programmer interacts with LISP during debugging are given. Although still incomplete, the system runs satisfactorily and can be used easily by beginning students and by psychologists interested in how people learn complex subjects. 相似文献
994.
Ryan D. Tweney Michael E. Doherty Winifred J. Worner Daniel B. Pliske Clifford R. Mynatt Kimberly A. Gross Daniel L. Arkkelin 《Quarterly journal of experimental psychology (2006)》1980,32(1):109-123
It has long been known that subjects in certain inference tasks will seek evidence which can confirm their present hypotheses, even in situations where disconfirmatory evidence could be more informative. We sought to alter this tendency in a series of experiments which employed a rule discovery task, the 2-4-6 problem first described by Wason. The first experiment instructionally modified subjects confirmatory tendencies. While a disconfirmatory strategy was easily induced, it did not lead to greater efficiency in discovering the rule. The second experiment introduced subjects to the possibility of disconfirmation only after they had developed a strongly held hypothesis through the use of confirmatory evidence. This manipulation also failed to alter the efficiency of rule discovery. In the third experiment, subjects were taught to use multiple hypotheses at each step, in the manner of Platt's “Strong Inference”. This operation actually worsened performance. Finally, in the fourth experiment, the structure of the problem was altered slightly by asking subjects to seek two interrelated rules. A dramatic increase in performance resulted, perhaps because information which in previous tasks was seen as merely erroneous could now be related to an alternative rule. The four studies have broad implications for the psychological study of inference processes in general, and for the study of scientific inference in particular. 相似文献
995.
S. A. Corson E. O’L. Corson R. E. Becker B. E. Ginsburg A. Trattner R. L. Connor L. A. Lucas J. Panksepp J. P. Scott 《Integrative psychological & behavioral science》1980,15(1):5-11
A model of childhood hyperkinesis, using the Telomian-beagle hybrid dog, is described, demonstrating the interactions of genetics and separation in the development of this syndrome and in the favorable responses of some of these dogs to amphetamine. This work represents the collaboration of three laboratories, utilizing chiefly methods of inhibitory training. Inducing separation distress enhanced the resistance to inhibitory training and the favorable responses to amphetamine. 相似文献
996.
Robert Barcus Andrew I. Schwebel Samuel A. Corson 《Integrative psychological & behavioral science》1980,15(4):183-187
This report describes the use of an animal model for testing the relationship between the effects of ingesting food additives and hyperactivity. Telomian × beagle hybrid dogs were chosen as subjects because this breed has been observed to exhibit behavior seen as analogous to the hyperactivity of children. Two studies were conducted by adding or deleting butylated hydroxyanisole and Food, Drug, and Cosmetic red dye number 40 to the diet of each dog. A test of sitting was performed to measure the level of activity. While a relationship was not observed between the ingestion of the additive and the level of activity, several issues pertaining to the use of the animal model became apparent. These issues and the use of animals for future research in this area are discussed. 相似文献
997.
Jones MB 《Journal of motor behavior》1980,12(1):69-73
As students progress to higher and higher levels in the acquisition of a skill their number gets smaller and smaller. This article concerns the average length of time it takes the members of these successively smaller groups to complete earlier stages of skill acquisition. In the data presented, which concern Red Cross swimming, the more advanced a group is the less time its members take on the average to complete a preceding stage (sequential precession). The discussion section brings out a second relation in the same data: Namely, the further the same students advance in skill acquisition the smaller the advantage they enjoy over other students at the same level (diminishing returns). 相似文献
998.
Hand differences in the rate and variability of rapid tapping were evaluated for the intertap interval and its constituents-the key depression and key release phases of each tap. To accentuate potential hand differences, only subjects with a clear manual superiority in one hand were included. Relative manual proficiency on Fitts' reciprocal tapping task was used to exclude individuals with less-defined hand superiority or dominance, and to categorize subjects as having a dominant left (n=13) or right (n=11) hand. Analysis of variance indicated the dominant hand to have a shorter average intertap interval and thus a faster tapping rate. This hand difference in rate was found to be significant for the key-depression phase, but not the key-release.phase, of the tap. In each handedness group the dominant hand exhibited less variability in the intertap interval and both constituents. Potential associations of these findings with hemispheric asymmetries in sequential ability are discussed. 相似文献
999.
Statistical significance tests are derived and evaluated for measuring apparent differences between an obtained and an expected binormal ROC curve, between two independent binormal ROC curves, and among groups of independent binormal ROC curves. A binormal ROC curve is described by two parameters which represent the spread of the means and the ratio of the standard deviations of the two underlying Gaussian decision variable distributions. To test the significance of apparent differences between or among ROC curves, approximate χ2 statistics for each of the three tests were constructed from maximum likelihood estimates of the two parameters defining the binormal ROC curve. The performance of each test statistic was evaluated by simulating five-category rating scale data with equal numbers of noise and signal-plus-noise trials (set at 50, 250, and 500) for each of three typical ROC curves. For the significance test involving only one ROC curve, rating scale data were generated from the chance diagonal of the ROC space also. Although test performance was found to be somewhat dependent on the number of trials and on the location of the ROC curve in the ROC space, comparisons of the obtained and expected fractions of (falsely) significant results at various α levels showed the proposed statistical significance tests to be reliable under practical experimental conditions. 相似文献
1000.
Lawrence I. Goldberger Lynne M. Ausman R.Charles Boelkins 《Learning and motivation》1980,11(2):185-207
The long-term effects of infantile malnutrition on information processing were studied in squirrel monkeys. From 2 through 8 weeks of age, four low-calorie infants were fed reduced amounts of a high protein diet, limiting their mean body weight gain to 23% of that of four well-fed controls, with all of this gain occurring during the first 2 weeks on the low-calorie diet. Thereafter, both groups received the standard diet ad libitum. At 68 weeks of age, incidental learning was tested by introducing shape cues that were redundant to the solution of a previously learned, two-choice, color discrimination. Removal of the color cues showed that the low-calorie monkeys had learned significantly less about the shape cues than had the controls. The basis for this incidental learning failure was then examined with an embedded-figures dicrimination, to measure attentional ability, and a novel stimulus substitution task, to measure curiosity. The groups did not differ in detecting embedded figures, but the low-calorie monkeys were significantly less likely than controls to select or handle novel stimuli that had been substituted for previously learned discriminative cues. It was concluded that undernutrition in infancy may induce a long-term strategy of only learning information which leads to an immediate reward, while suppressing the acquisition of information due to intrinsic curiosity. 相似文献