全文获取类型
收费全文 | 60396篇 |
免费 | 2509篇 |
国内免费 | 31篇 |
出版年
2020年 | 614篇 |
2019年 | 815篇 |
2018年 | 1107篇 |
2017年 | 1110篇 |
2016年 | 1152篇 |
2015年 | 798篇 |
2014年 | 994篇 |
2013年 | 4614篇 |
2012年 | 1856篇 |
2011年 | 1940篇 |
2010年 | 1143篇 |
2009年 | 1205篇 |
2008年 | 1656篇 |
2007年 | 1645篇 |
2006年 | 1516篇 |
2005年 | 1351篇 |
2004年 | 1299篇 |
2003年 | 1196篇 |
2002年 | 1244篇 |
2001年 | 1886篇 |
2000年 | 1834篇 |
1999年 | 1370篇 |
1998年 | 679篇 |
1997年 | 588篇 |
1995年 | 577篇 |
1992年 | 1088篇 |
1991年 | 1053篇 |
1990年 | 1021篇 |
1989年 | 1012篇 |
1988年 | 986篇 |
1987年 | 908篇 |
1986年 | 954篇 |
1985年 | 1031篇 |
1984年 | 837篇 |
1983年 | 790篇 |
1982年 | 632篇 |
1979年 | 938篇 |
1978年 | 674篇 |
1977年 | 594篇 |
1976年 | 634篇 |
1975年 | 763篇 |
1974年 | 875篇 |
1973年 | 910篇 |
1972年 | 766篇 |
1971年 | 693篇 |
1970年 | 656篇 |
1969年 | 690篇 |
1968年 | 851篇 |
1967年 | 754篇 |
1966年 | 736篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
We compare over a two-octave range the tonal, interval, and scale relationships of an ancient Chinese bell ensemble of the Zhou Dynasty and a modern bamboo flute. By using subjective pitches, a tonal system with simple harmonic partials (the flute) could be compared with a tonal system with complex inharmonic partials (the bell). We argue that the underlying musical scales of the bell ensemble and the flute are closely related and lie between an unequal-interval pure-system scale and the just-intonation scale. There is some evidence that a least interval of 60 or 66 cents figures in the flute scale, that both flute and bell scales include a 90-cent interval and a true (1,200-cent) octave, and that neither scale includes a 100-cent interval. Since there is a true octave, the scales cannot be cycles of fifths, and since there is no equal-temperament half-tone (100 cents), the scales cannot be equal in temperament. We conclude that the flute and Zhou bell scales are very similar if not the same. Apparently, strong cultural traditions and human perceptual constancies united to sustain a common flexible musical scale during 2,400 years. 相似文献
982.
983.
984.
Thomas P. Pallmeyer Edward B. Blanchard Lawrence C. Kolb 《Behaviour research and therapy》1986,24(6):645-652
The psychophysiological responses of heart rate (HR), systolic and diastolic blood pressure, skin conductance level and forehead electromyogram were compared during: rest, mental arithmetic and combat sounds of gradually increasing intensity for five groups of Ss: Vietnam veterans with post-traumatic stress disorder (PTSD); Vietnam veterans without PTSD but with comparable levels of combat experience; Vietnam veterans with other psychiatric disorders; Vietnam-era veterans; and nonveteran phobics. HR response to low-intensity combat sounds provided good discrimination between veterans with PTSD and the other groups and seems to resemble a conditioned emotional response. 相似文献
985.
The primary purpose of this investigation was to learn whether fears summate. Thirty Ss who reported and displayed fear in response to a snake and to a spider were shown each stimulus separately and then both stimuli simultaneously, in order to see if their fear responses would summate. They did, overall; however, if Stimulus 1 provoked greater fear than Stimulus 2, the simultaneous presentation of both stimuli was followed by a subtraction. Summation occurred when the second stimulus produced a larger fear response than the first stimulus, and the two were then presented simultaneously. 相似文献
986.
A rationale for a simple method for determining the inter-relatedness of two discrete fears was developed and subjected to experimental test. A system for making such distinctions proved to be satisfactory, but we found no relationship between the person's own estimation of the similarity of the two fears and the index of independence that was derived experimentally. Possible uses of the method are suggested. 相似文献
987.
G. M. van der Molen M. A. van den Hout J. Vroemen H. Lousberg E. Griez 《Behaviour research and therapy》1986,24(6):677-680
The effects of lactate infusion on subjective mood change were studied in two differently instructed groups, in a double-blind, placebo-controlled, cross-over study. Ss who were told that infusions would produce anxiety reported a significant change in the expected direction after lactate but not after glucose. Ss who were told that infusions would produce a state of pleasant excitement showed no change after either infusion. The possible role of cognitive parameters in experimentally-induced anxiety is discussed. 相似文献
988.
989.
All seven variables of containment theory were operationalized for questionnaires. Data were collected from 677 adolescents in a variety of high schools and correctional institutions, and divided into categories by race and sex. Factor analysis indicated that the structure of the relationships among the seven containment variables and delinquency was substantially different among black females. 相似文献
990.
The purpose of this study was to ascertain which sex education topics parents of preadolescents regarded as appropriate for their children. The sample was comprised of 146 respondents randomly selected from a class list of sixth graders in a suburban school district. A mailed, self-administered questionnaire listing 48 possible topics was used to elicit parental response. Pretesting found the questionnaire to be highly reliable (Cronbach's alpha = .95). Overall, parents strongly supported the inclusion of a broad range of sex education topics regardless of parental age, sex, marital status, income, education, or child's sex. Moreover, parents were largely in agreement with the inclusion of sensitive topics in addition to those which were more physiological or behavioral. Catholics more often than Protestants agreed with the inclusion of birth control, abortion, and sterilization even after controlling for income and education. Thus, the findings suggest that parents of sixth graders find a broad sex education program in the school appropriate. To this end, school officials and sex educators should not overlook the needs of preadolescents for sex education solely on the basis of perceived parental opposition. 相似文献