全文获取类型
收费全文 | 52543篇 |
免费 | 2100篇 |
国内免费 | 30篇 |
出版年
2020年 | 588篇 |
2019年 | 741篇 |
2018年 | 1065篇 |
2017年 | 1062篇 |
2016年 | 1120篇 |
2015年 | 744篇 |
2014年 | 919篇 |
2013年 | 4560篇 |
2012年 | 1660篇 |
2011年 | 1808篇 |
2010年 | 1054篇 |
2009年 | 1071篇 |
2008年 | 1640篇 |
2007年 | 1618篇 |
2006年 | 1432篇 |
2005年 | 1296篇 |
2004年 | 1275篇 |
2003年 | 1148篇 |
2002年 | 1199篇 |
2001年 | 1754篇 |
2000年 | 1663篇 |
1999年 | 1275篇 |
1998年 | 670篇 |
1997年 | 576篇 |
1996年 | 521篇 |
1995年 | 525篇 |
1994年 | 500篇 |
1993年 | 523篇 |
1992年 | 1015篇 |
1991年 | 955篇 |
1990年 | 940篇 |
1989年 | 854篇 |
1988年 | 816篇 |
1987年 | 804篇 |
1986年 | 811篇 |
1985年 | 865篇 |
1984年 | 673篇 |
1983年 | 585篇 |
1982年 | 480篇 |
1979年 | 663篇 |
1978年 | 496篇 |
1976年 | 461篇 |
1975年 | 601篇 |
1974年 | 631篇 |
1973年 | 598篇 |
1972年 | 549篇 |
1971年 | 484篇 |
1968年 | 545篇 |
1967年 | 549篇 |
1966年 | 478篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
861.
For 40 males who smoked 20 cigarettes a day titratable acidity of the urine was significantly correlated with nicotine/cotinine excretion at several sample intervals, as was urinary pH, but not urinary acidity and daily cigarette consumption or serum COHB. 相似文献
862.
6 adult subjects (3 men, 3 women) produced highly similar spontaneous speech utterances in quiet and with 90-dB SPL white noise. The frequency of occurrence of perceptual judgments of primary stressing in an utterance was not affected by the masking noise. This finding supplements our previous report that variability for stress production of fundamental frequency (fo) during spontaneous speech was preserved under short-term auditory disruption. Also, it adds further support to the contention that fo is under open-loop regulation. 相似文献
863.
The purpose of the study was to document children's perception of parental exercise, relating these perceptions to (1) the self-reported parents' habits of exercise, and (2) the children's own activity patterns. The subjects were 198 students of both sexes, aged 12 to 14 yr. and enrolled in school Grades 7 to 9. A standard questionnaire assessed their perceptions of parental and personal physical activity. Both parents of each subject also reported their respective levels of habitual physical activity. Congruence between the children's perceptions and the self-reported exercise habits of the opposite-sex parent differed for boys and girls, increasing for boys and decreasing for girls between Grades 7 and 9. No significant associations were observed between the children's perception of parental exercise patterns and their own like habits. This suggests that during adolescence parental influences are minimized by other factors, personal or environmental. 相似文献
864.
Locus of inhibition effects in the priming of lexical decisions: pre- or postlexical access? 总被引:1,自引:0,他引:1
The lexical decision task has been employed to investigate the effects of semantic context on word recognition. A frequent finding from the task is that “word” responses are slower when the target is preceded by an unrelated word than when it is preceded by a neutral stimulus. This inhibition effect has been interpreted as indicating that the unrelated prime interferes with word-recognition processes operating on the target. In three experiments, the effects of unrelated primes were compared for a lexical decision and word naming task. Although large inhibition effects were found for the lexical decision task in all experiments, no inhibition effects were observed for the naming task. The results are interpreted as demonstrating that inhibition effects in the lexical decision task are not on recognition processes; rather they are located at processes operating after recognition of the target has occurred. 相似文献
865.
Punctuation in 20 radio homilies by four speakers accounted for 76% of pause time and 64% of pause number. Pause duration varied systematically according to punctuation type. Commas accounted for 82% of punctuated positionsnot used for pausing.RRelevance for theories of text unitization is discussed. Both typographical and temporal measures are compared with a similar corpus of German homilies. 相似文献
866.
867.
Thomas A. Hulbert Charles L. Gdowski David Lachar 《Journal of abnormal child psychology》1986,14(1):115-122
Mothers' and fathers' responses on the Personality Inventory for Children (PIC) were compared for 360 clinic-referred children and adolescents. Interparent agreement was measured by several different indices. Correlations between parental pairs of scale T-scores derived from each parent averaged .66 for 13 of the profile scales; 9 of the scales exceeded this value. In contrast, mothers and fathers agreed in the classification of the presence of clinical significance an average of 77% of the time across these 13 scales, and pairs of parental PIC profiles contained an average of 3 scales in disagreement. The type of index used to measure interparent agreement was found to affect the results. The discussion examines the nature of interparent disagreement and addresses the implications regarding the use of fathers as informants on this instrument.This article is based on Thomas A. Hulbert's master's thesis. The authors extend their appreciation to James Orisell and Dena Mussaff for their assistance in data preparation and analysis. 相似文献
868.
Decision processes in visual discrimination of line orientation 总被引:4,自引:0,他引:4
R Vogels G A Orban 《Journal of experimental psychology. Human perception and performance》1986,12(2):115-132
The contribution of decision factors to the meridional variations in line orientation discrimination was determined for two-alternative forced-choice experimental designs. Using Johnson's (1980) formalization of decision processes in discrimination tasks, we identified three decision factors: the decision rule, memory variance, and criterial noise. In a first experiment, we showed the effect of experimental design on orientation discrimination to be similar at horizontal and oblique standard orientations, indicating that the meridional variations in orientation discrimination were not due to a decision rule anisotropy. In a second experiment, the effect of the interstimulus interval was also found to be similar at both standard orientations, suggesting that the memory variance is isotropic in the orientation domain. The results of two other experiments supported the hypothesis that the meridional variations in orientation discrimination are not due to a criterial noise anisotropy. These different results strongly suggested that the oblique effect in line orientation discrimination is due to sensorial factors rather than to decision factors. Therefore, they further support the hypothesis linking the anisotropy of the preferred orientation distribution of Area 17-S cells (a single physiologically defined class of cells in the primary visual cortex) and the meridional variations in line orientation discrimination. 相似文献
869.
J A Thomson 《Journal of experimental psychology. Human perception and performance》1986,12(3):392-393
Recently, Elliott (1986) has reported data that he claims are inconsistent with my hypothesis that a short-term motor memory system exists for guiding locomotion and other actions in space (Thomson, 1983). In fact, methodological flaws in Elliott's design make such conclusions unjustified and inappropriate. Moreover, insofar as comparisons can be made at all, the results are completely consistent with my own data. 相似文献
870.
Much research on emotional facial expression employs posed expressions and expressive subjects. To test the generalizability of this research to more spontaneous expressions of both expressive and nonexpressive posers, subjects engaged in happy, sad, angry, and neutral imagery, and voluntarily posed happy, sad, and angry facial expressions while facial muscle activity (brow, cheek, and mouth regions) and autonomic activity (skin resistance and heart period) were recorded. Subjects were classified as expressive or nonexpressive on the basis of the intensity of their posed expressions. The posed and imagery-induced expressions were similar, but not identical. Brow activity present in the imagery-induced sad expressions was weak or absent in the posed ones. Both nonexpressive and expressive subjects demonstrated similar heart rate acceleration during emotional imagery and demonstrated similar posed and imagery-induced happy expressions, but nonexpressive subjects showed little facial activity during both their posed and imagery-induced sad and angry expressions. The implications of these findings are discussed. 相似文献