全文获取类型
收费全文 | 19684篇 |
免费 | 1742篇 |
国内免费 | 1402篇 |
专业分类
22828篇 |
出版年
2024年 | 46篇 |
2023年 | 349篇 |
2022年 | 306篇 |
2021年 | 351篇 |
2020年 | 718篇 |
2019年 | 751篇 |
2018年 | 737篇 |
2017年 | 836篇 |
2016年 | 811篇 |
2015年 | 533篇 |
2014年 | 708篇 |
2013年 | 2231篇 |
2012年 | 449篇 |
2011年 | 534篇 |
2010年 | 469篇 |
2009年 | 681篇 |
2008年 | 851篇 |
2007年 | 953篇 |
2006年 | 927篇 |
2005年 | 802篇 |
2004年 | 677篇 |
2003年 | 566篇 |
2002年 | 505篇 |
2001年 | 327篇 |
2000年 | 304篇 |
1999年 | 258篇 |
1998年 | 206篇 |
1997年 | 182篇 |
1996年 | 146篇 |
1995年 | 123篇 |
1994年 | 121篇 |
1993年 | 95篇 |
1992年 | 79篇 |
1991年 | 52篇 |
1990年 | 51篇 |
1989年 | 34篇 |
1988年 | 41篇 |
1985年 | 394篇 |
1984年 | 447篇 |
1983年 | 355篇 |
1982年 | 458篇 |
1981年 | 448篇 |
1980年 | 450篇 |
1979年 | 401篇 |
1978年 | 463篇 |
1977年 | 365篇 |
1976年 | 373篇 |
1975年 | 287篇 |
1974年 | 282篇 |
1973年 | 244篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
231.
驾驶员心理品质检测中的杆型人形图法 总被引:1,自引:0,他引:1
在汽车驾驶员心理品质检测研究中,我们根据数学中的多变量图分析方法,并汲取简笔画的优点,用19个人形图变量代表检测所得的17种心理品质数据,来具体、形象地再现每个驾驶员心理品质变量的整体关系。这对于检测结果的分类或进行系统化分析具有重要的实用意义。 相似文献
232.
Lindsay St. Claire 《Journal of community & applied social psychology》1993,3(3):183-195
Briefs about mentally retarded people are more negative than briefs about other social categories; professionals, such as medical doctors evaluate them most negatively of all. It was hypothesized (a) that medics' beliefs about mentally retarded people are mediated by psychological salience of their clinical social identification, rather than by personal characteristics that medics happen to share and (b) that such beliefs will bias decisions, rather than enhance accuracy. Forty-five doctors and medical students were randomly assigned to conditions designed to enhance salience of their shared clinical social identification or individual self-perceptions. Subjects completed semantic differentials about mentally retarded people and distinguished between slides of ‘mentally retarded’ and ‘normal’ children. Beliefs of subjects in the medical condition were significantly more negative than those in the personal condition. A signal detection analysis revealed no difference between conditions in subjects' ability to distinguish between children but showed that subjects in the medical condition were significantly more likely to judge a child ‘mentally retarded’ when in doubt. Results were discussed within an information processing framework and supported the idea that a salient clinical social identity can mediate beliefs that are likely to handicap patients. 相似文献
233.
Ronald C. Martella Ph.D. Ian J. Leonard B.S. Nancy E. Marchand-Martella Ph.D. Martin Agran Ph.D. 《Journal of Behavioral Education》1993,3(1):77-86
We examined the effects of a self-monitoring program on reducing the frequency of negative statements of a student with mild mental retardation who was enrolled in a self-contained classroom at a middle school. A changing criterion design was used within a multiple baseline design across two classroom periods. Additionally, the frequency of positive statements was reported. The results showed a decrease in the number of negative statements, and an increase in the number of positive statements. Maintenance data collected up to 8 weeks after the program ended indicated that the student continued to emit positive rather than negative statements. The use of this procedure to decelerate undesirable behavior is discussed. 相似文献
234.
The crane's foot: The rise of the pedigree in human genetics 总被引:1,自引:1,他引:0
Robert G. Resta 《Journal of genetic counseling》1993,2(4):235-260
The standard pedigree used by geneticists is intimately connected to the history of genetics. Pedigrees drawn today are based on standards established in the early decades of the twentieth century. Those standards were established by geneticists who pursued an active interest in eugenics. The slightly different standards followed in America vs. England to some extent followed the stronger support of Mendelism by the Americans, as well as the individual preferences of the leading human geneticists in those countries. 相似文献
235.
Kimberly Hoagwood Ph.D. Ann A. Hohmann Ph.D. M.S.P.H. 《Journal of child and family studies》1993,2(3):259-268
This article describes an important new area of research on services for children and adolescents with mental disorders at the National Institute of Mental Health, the parameters of mental health services research for youth, and the opportunities that are available for grant-funded investigations in this area. 相似文献
236.
K. W. M. Fulford 《Theoretical medicine and bioethics》1993,14(4):305-320
Analyses of biological concepts of disease and social conceptions of health indicate that they are structurally interdependent. This in turn suggests the need for a bridge theory of illness. The main features of such a theory are an emphasis on the logical properties of value terms, close attention to the features of the experience of illness, and an analysis of this experience as action failure, drawing directly on the internal structure of action. The practical applications of this theory are outlined for a number of problems in each of the three main practical areas, clinical work, teaching and research. In each case the resources of the theory suggest new models and generate new results. The full practical significance of the theory, however, is shown to consist in the way in which it ties together biological and social theories into an integrated picture of the conceptual structure of medicine as a whole. It is argued, finally, that practical efficiency of this kind is a test of theory not only in the philosophy of medicine but also in general philosophy. 相似文献
237.
Substitutability is a construct borrowed from microeconomics that describes a continuum of possible interactions among the reinforcers in a given situation. Highly substitutable reinforcers, which occupy one end of the continuum, are readily traded for each other due to their functional similarity. Complementary reinforcers, at the other end of the continuum, tend to be consumed jointly in fairly rigid proportion, and therefore cannot be traded for one another except to achieve that proportion. At the center of the continuum are reinforcers that are independent with respect to each other; consumption of one has no influence on consumption of another. Psychological research and analyses in terms of substitutability employ standard operant conditioning paradigms in which humans and nonhumans choose between alternative reinforcers. The range of reinforcer interactions found in these studies is more readily accommodated and predicted when behavior-analytic models of choice consider issues of substitutability. New insights are gained into such areas as eating and drinking, electrical brain stimulation, temporal separation of choice alternatives, behavior therapy, drug use, and addictions. Moreover, the generalized matching law (Baum, 1974) gains greater explanatory power and comprehensiveness when measures of substitutability are included. 相似文献
238.
Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond the effect exerted by frequency of primary reinforcement. 相似文献
239.
Violations of transitivity: Implications for a theory of contextual choice 总被引:1,自引:1,他引:0 下载免费PDF全文
Grace RC 《Journal of the experimental analysis of behavior》1993,60(1):185-201
Violations of strong stochastic transitivity in concurrent-chains choice were first reported by Navarick and Fantino. In a series of articles, Navarick and Fantino concluded that neither a unidimensional model capable of predicting exact choice probabilities nor a fixed-variable equivalence rule was possible for the concurrent-chains procedure. I show that when choice is modeled contextually (i.e., when preference for a schedule is affected by factors other than the schedule itself, e.g., aspects of the alternative schedule), a unidimensional, exact-choice probability model is possible that both predicts the intransitivities reported by Navarick and Fantino and provides a fixed-variable equivalence rule for the concurrent-chains procedure. The contextual model is an extension of the generalized matching law and violates a key assumption underlying traditional choice models—simple scalability—because of (a) schedule interdependence and (b) bias from procedural contingencies. Therefore, strong stochastic transitivity cannot be expected to hold. Contextual scalability is analyzed to reveal a hierarchy of context effects in choice. Navarick and Fantino's intransitivities can be satisfactorily explained by bias. If attribute sensitivity is context dependent, however, and if there are similarity structures among choice alternatives, the contextual model is shown to be able to predict violations of ordinal preference. Therefore, it may be possible to formulate a deterministic, general psychophysical model of choice as a behavioral alternative to probabilistic, multidimensional choice theories. 相似文献
240.
Unit price as a useful metric in analyzing effects of reinforcer magnitude. 总被引:7,自引:6,他引:1 下载免费PDF全文
R J DeGrandpre W K Bickel J R Hughes M P Layng G Badger 《Journal of the experimental analysis of behavior》1993,60(3):641-666
In this paper, we applied the behavioral-economic concept of unit price to the study of reinforcer magnitude in an attempt to provide a consistent account of the effects of reinforcer magnitude on behavior. Recent research in the experimental analysis of behavior and in behavioral pharmacology suggests that reinforcer magnitude interacts with the schedule of reinforcement to determine response rate and total consumption. The utility of the unit-price concept thus stems from its ability to quantify this interaction as a cost-benefit ratio (i.e., unit price = characteristics of the schedule of reinforcement divided by magnitude of reinforcement). Research employing the unit-price concept has shown that as unit price increases, a positively decelerating function exists for consumption (i.e., a function with an increasingly negative slope, when plotted on log coordinates) and a bitonic function exists for response rate. Based on these findings, the present analysis applied the unit-price concept to those studies of reinforcer magnitude and drug self-administration that examined the effects of reinforcer magnitude on response rate using simple schedules of reinforcement (e.g., fixed-ratio schedule). This resulted in three findings: (a) Reinforcer-magnitude manipulations and schedule manipulations interact in a manner that can be quantified in terms of unit price as benefit and cost factors, respectively; (b) different reinforcer-magnitude manipulations are functionally interchangeable as benefit factors in the unit-price ratio; and (c) these conclusions appear warranted despite the differences in reinforcers (food or drug), species (dogs, monkeys, or rats), and schedules (interval or ratio), and despite the fact that these studies were not designed for a unit-price analysis. In methodological terms, these results provide further evidence that employing the unit-price concept is a parsimonious method for examining the effects of reinforcer magnitude. In theoretical terms, these results suggest that a single process may underlie the effect of combined reinforcer-magnitude and schedule manipulations. 相似文献