全文获取类型
收费全文 | 31013篇 |
免费 | 1051篇 |
国内免费 | 17篇 |
专业分类
32081篇 |
出版年
2020年 | 291篇 |
2019年 | 330篇 |
2018年 | 1839篇 |
2017年 | 1702篇 |
2016年 | 1357篇 |
2015年 | 411篇 |
2014年 | 413篇 |
2013年 | 1831篇 |
2012年 | 1008篇 |
2011年 | 1846篇 |
2010年 | 1542篇 |
2009年 | 1040篇 |
2008年 | 1370篇 |
2007年 | 1611篇 |
2006年 | 533篇 |
2005年 | 526篇 |
2004年 | 507篇 |
2003年 | 463篇 |
2002年 | 458篇 |
2001年 | 899篇 |
2000年 | 893篇 |
1999年 | 600篇 |
1998年 | 233篇 |
1997年 | 217篇 |
1996年 | 185篇 |
1993年 | 188篇 |
1992年 | 466篇 |
1991年 | 421篇 |
1990年 | 443篇 |
1989年 | 416篇 |
1988年 | 399篇 |
1987年 | 373篇 |
1986年 | 396篇 |
1985年 | 392篇 |
1984年 | 318篇 |
1983年 | 265篇 |
1981年 | 184篇 |
1979年 | 297篇 |
1978年 | 215篇 |
1976年 | 187篇 |
1975年 | 261篇 |
1974年 | 337篇 |
1973年 | 286篇 |
1972年 | 277篇 |
1971年 | 242篇 |
1970年 | 219篇 |
1969年 | 277篇 |
1968年 | 269篇 |
1967年 | 246篇 |
1966年 | 232篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
931.
Subjects (N = 32) were asked to synchronize a motor response with tones in auditory patterns. These patterns were created from six tones and six intertone intervals of equal duration. The pitch of the first tone differed from the others. It was found that subjects used three types of timing in their motor response: (1) the first intertone interval was prolonged and the second interval was shortened, (2) the second intertone interval was prolonged and the first interval was shortened, and/or (3) the first interval and the second interval were of approximately the same length. The prolongation of the fifth interval was observed during all three types of timing. The results are explained using the concept of suprasegmental control of timing, which explains a prolongation of intervals at critical control point of the patterns. The occurrence of three different strategies of timing is discussed in connection with similar principles in musical performance. 相似文献
932.
The experiments in which the strengths of pattern and of fusion differing in kind from brightness were used as measures indicated that the visual system could distinguish between illuminance and reflectance. From this result and an observation of gray papers by a microscope, it is assumed that luminance has two aspects, one refers to the macroscopic density of photons and another to the proportion of the reflected microscopic areas to the absorbed microscopic areas so that brightness constancy occurs in relation to each of the patterns of the various sizes from a macroscopic pattern visible to the naked eye to a microscopic pattern not visible. It is also mentioned that the strength of fusion is rare but promising as a measure for analyzing brightness. 相似文献
933.
934.
Competent and incompetent criminal defendants: a quantitative review of comparative research 总被引:2,自引:0,他引:2
Thirty studies comparing competent and incompetent criminal defendants (N = 8,170) were quantitatively reviewed to identify variables associated with judgments about defendants' competency to stand trial. Effect sizes reflecting the magnitude of the relationship between competency status and defendant characteristics were derived and averaged across studies. The characteristics most strongly related to incompetency were (a) poor performance on psychological tests or interviews specifically designed to assess defendants' legally relevant functional abilities, (b) a psychotic diagnosis, and (c) psychiatric symptoms reflective of severe psychopathology. To a lesser degree, traditional psychological tests, previous psychiatric hospitalization, previous legal involvement, marital resources, and demographic characteristics were also related to competency status. Although these results are generally consistent with the legal standard for competency to stand trial, some of the correlates of competency may reflect potential biases in the decision-making process. Limitations of existing research and directions for future inquiry are discussed. 相似文献
935.
A dating questionnaire was completed by 248 undergraduate college students who were either dating someone in an exclusive relationship or were not going steady. Responses to this questionnaire by students not going steady with someone indicated that 54 college-age men were more active at initiating and more successful at getting dates than the 70 women. However, between one-half and three-fourths of the college women reported having initiated dates with men. Both sexes experienced considerable anxiety while initiating a date which suggests a self-help system might be designed to ameliorate this problem. 相似文献
936.
The Reasons for Living Inventory: psychometric properties 总被引:1,自引:0,他引:1
The test-retest reliability, internal consistency reliability, normative, and item analysis data of the Reasons for Living Inventory were investigated in a sample of 116 college students. The inventory has six subscales, each of which assesses a category of adaptive beliefs and expectations considered reasons for not committing suicide. The inventory was administered twice, with a 3-week interval between testings. Test-retest coefficients for the men, women, and total sample were moderate to high. The alpha coefficients and item-total correlations for the subscales and the total inventory provided strong support for internal consistency. 26 items were consistently endorsed by 30% or more of our total sample as "extremely important," while only four were suggested as "not at all important" reasons for not committing suicide. 相似文献
937.
A model of category effects on reports from memory is presented. The model holds that stimuli are represented at 2 levels of detail: a fine-grain value and a category. When memory is inexact but people must report an exact value, they use estimation processes that combine the remembered stimulus value with category information. The proposed estimation processes include truncation at category boundaries and weighting with a central (prototypic) category value. These processes introduce bias in reporting even when memory is unbiased, but nevertheless may improve overall accuracy (by decreasing the variability of reports). Four experiments are presented in which people report the location of a dot in a circle. Subjects spontaneously impose horizontal and vertical boundaries that divide the circle into quadrants. They misplace dots toward a central (prototypic) location in each quadrant, as predicted by the model. The proposed model has broad implications; notably, it has the potential to explain biases of the sort described in psychophysics (contraction bias and the bias captured by Weber's law) as well as symmetries in similarity judgments, without positing distorted representations of physical scales. 相似文献
938.
939.
This study compared the developmental expectations and parenting behaviors of 52 mothers and fathers with children between the ages of 1 and 4 years, using the Parenting Inventory: Young Children. While both mothers and fathers were nurturing parents, mothers obtained significantly higher nurturing scores. Possible reasons for this difference were discussed. Developmental expectations and discipline strategies did not differ between mothers and fathers. 相似文献
940.
This study examined three factors affecting college students' attributions of blame for an AIDS patient's disease: sexual orientation of the patient, mode of HIV transmission, and the sex of the subject. 148 subjects read one of six vignettes describing an hypothetical AIDS patient who was described as either an heterosexual or an homosexual man who contracted HIV through one of three avenues: blood transfusion, sexual contact, or IV drug use. The homosexual AIDS patient was considered more to blame for his illness than the heterosexual AIDS patient, but only when mode of transmission was sexual contact. In addition, mode of HIV transmission was a significant factor in attributions of responsibility, as the patient who contracted HIV through a blood transfusion was rated as less responsible than the patient who contracted HIV through sexual behavior or IV drug use. Women consistently rated the AIDS patient as less responsible than did men. 相似文献