全文获取类型
收费全文 | 16159篇 |
免费 | 619篇 |
国内免费 | 4篇 |
专业分类
16782篇 |
出版年
2019年 | 213篇 |
2018年 | 258篇 |
2017年 | 219篇 |
2016年 | 257篇 |
2015年 | 169篇 |
2014年 | 262篇 |
2013年 | 1273篇 |
2012年 | 435篇 |
2011年 | 487篇 |
2010年 | 292篇 |
2009年 | 314篇 |
2008年 | 416篇 |
2007年 | 442篇 |
2006年 | 422篇 |
2005年 | 344篇 |
2004年 | 373篇 |
2003年 | 335篇 |
2002年 | 331篇 |
2001年 | 451篇 |
2000年 | 510篇 |
1999年 | 343篇 |
1998年 | 208篇 |
1997年 | 158篇 |
1996年 | 167篇 |
1995年 | 168篇 |
1992年 | 277篇 |
1991年 | 285篇 |
1990年 | 297篇 |
1989年 | 280篇 |
1988年 | 268篇 |
1987年 | 234篇 |
1986年 | 247篇 |
1985年 | 260篇 |
1984年 | 192篇 |
1983年 | 208篇 |
1982年 | 158篇 |
1980年 | 160篇 |
1979年 | 250篇 |
1978年 | 217篇 |
1977年 | 152篇 |
1975年 | 215篇 |
1974年 | 243篇 |
1973年 | 268篇 |
1972年 | 225篇 |
1971年 | 210篇 |
1970年 | 163篇 |
1969年 | 195篇 |
1968年 | 249篇 |
1967年 | 239篇 |
1966年 | 209篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Adult age differences were explored on 3 short tests of the ability to generate and manipulate mental images. Age-related decrements were found in all 3 tests and were especially marked on the Clock Test. The tests are all reliable, as shown by test-retest reliability coefficients. Correlations also revealed that the Brooks Letter Test and the East-West Test appear to tap one common underlying ability, whereas the Clock Test measured a somewhat different ability. The East-West and Clock tests, in particular, may provide rapid and easily administered assessments of age-related changes in aspects of mental imagery. 相似文献
82.
The development of a campus-based Substance Abuse Prevention Program (SAPP) is discussed. The program has been designed in accordance with recommendations made by prominent authorities in this field, keeping in mind the needs of the campus at which the program is located. Suggestions for developing such programs are provided. 相似文献
83.
84.
Joyce F. Lakey 《Journal of Addictions & Offender Counseling》1992,13(1):2-10
The author describes mythical beliefs, thinking errors, and faulty attitudes collected from a group of male juvenile sex offenders. Therapists need this information to develop effective treatment strategies for replacing distortions and misperceptions with correct and moral information as a foundation for change. 相似文献
85.
A running-wheel movement-detection method is described for use with a modified 1350 Commodore mouse and a Commodore 64, is described. The movement-detection method allows for the detection of partial revolutions and direction of movement, but requires no interface equipment. The modified running wheel is discussed as a new technique that may be useful for bridging empirical and theoretical differences between free-operant and discrete-trial runway procedures. 相似文献
86.
Neonatal imitation of tongue protrusion and mouth opening: Methodological aspects and evidence of early individual differences 总被引:3,自引:0,他引:3
MIKAEL HEIMANN KEITH E. NELSON JOSEPH SCHALLER 《Scandinavian journal of psychology》1989,30(2):90-101
The present work examines imitation of mouth opening and tongue protrusion in 32 full-term infants at three different occasions: When the infants are two to three days, three weeks, and three months old. The analysis focuses (1) on individual differences in imitative behaviour and (2) on how to operationalize the infants' responses. The overall group analysis revealed that imitation of tongue protrusion was statistically significant for both two- to three-day-old and three-week-old infants but not when the children had become three months old. No statistically significant effect was observed for imitation of mouth opening. Two different imitation indexes were constructed in order to assess individual differences in early imitative behaviour. Results show that short-term stability in imitative tendencies exists between the first and second observation. The results further reveal that methodological factors must be seriously considered when studying neonatal imitation: the overall imitation found for tongue protrusion is demonstrated to be dependent on how the infants' responses are coded. 相似文献
87.
Millsap and Meredith (1988) have developed a generalization of principal components analysis for the simultaneous analysis of a number of variables observed in several populations or on several occasions. The algorithm they provide has some disadvantages. The present paper offers two alternating least squares algorithms for their method, suitable for small and large data sets, respectively. Lower and upper bounds are given for the loss function to be minimized in the Millsap and Meredith method. These can serve to indicate whether or not a global optimum for the simultaneous components analysis problem has been attained.Financial support by the Netherlands organization for scientific research (NWO) is gratefully acknowledged. 相似文献
88.
THE RELATIONSHIP BETWEEN RECRUITING SOURCE, APPLICANT QUALITY, AND HIRE PERFORMANCE: AN ANALYSIS BY SEX, ETHNICITY, AND AGE 总被引:2,自引:0,他引:2
This study investigated both an applicant pool and its resulting class of new hires in an attempt to clarify a number of empirical questions concerning recruiting source effectiveness. A pre-established database of applicants and hires for the job of life insurance agent in a large insurance company was analyzed for recruiting activity. Differences in applicant quality and new hire survival were found in favor of the informal recruiting sources. A second measure of hire success, new business commission credits, failed to show differences across recruiting sources. The informal recruiting sources yielded significantly higher selection ratios than did formal sources for all groups. Examination of recruiting source use showed significant group differences, with females and blacks using the formal recruiting sources more frequently than males, non-minorities, and Hispanics. While the informal recruiting sources yielded higher quality applicants and more successful hires for all groups, this research cautions that the implementation of revised recruiting policies must be carefully monitored for adverse effects on protected groups. 相似文献
89.
Trace mineral analysis of human hair was utilized to determine whether violent and nonviolent criminals could be differentiated on the basis of concentrations of levels of major and trace minerals. 40 violent and 40 nonviolent inmates from a prison population were selected for study. 27 mineral levels were analyzed and a discriminant function analysis correctly classified 86% of the violent and 78% of the nonviolent inmates. The results lent support to the hypothesis that significantly different levels of trace minerals could be found between the two groups. 相似文献
90.
F Postrach 《Psychiatrie, Neurologie, und medizinische Psychologie》1989,41(9):539-544
A case of episodic manifestation of semiparalysis agitans is described, accompanied by severe demential personality change and precursory hallucinatory symptoms, which is made the basis for the discussion of aspects of mental disorders, notably dementia and symptoms resembling schizophrenia, in Parkinsonian patients. By way of allusion to Glass, a diagnosis including a very extensive, complex, symptomatology is made of a Parkinsonian syndrome. 相似文献