全文获取类型
收费全文 | 32079篇 |
免费 | 1361篇 |
国内免费 | 18篇 |
专业分类
33458篇 |
出版年
2020年 | 332篇 |
2019年 | 442篇 |
2018年 | 596篇 |
2017年 | 564篇 |
2016年 | 604篇 |
2015年 | 440篇 |
2014年 | 556篇 |
2013年 | 2542篇 |
2012年 | 971篇 |
2011年 | 1095篇 |
2010年 | 644篇 |
2009年 | 649篇 |
2008年 | 858篇 |
2007年 | 866篇 |
2006年 | 792篇 |
2005年 | 662篇 |
2004年 | 680篇 |
2003年 | 639篇 |
2002年 | 633篇 |
2001年 | 1101篇 |
2000年 | 1153篇 |
1999年 | 779篇 |
1998年 | 374篇 |
1997年 | 320篇 |
1996年 | 299篇 |
1995年 | 288篇 |
1992年 | 612篇 |
1991年 | 588篇 |
1990年 | 615篇 |
1989年 | 588篇 |
1988年 | 567篇 |
1987年 | 504篇 |
1986年 | 532篇 |
1985年 | 543篇 |
1984年 | 421篇 |
1983年 | 401篇 |
1982年 | 279篇 |
1979年 | 429篇 |
1978年 | 368篇 |
1977年 | 274篇 |
1975年 | 390篇 |
1974年 | 470篇 |
1973年 | 451篇 |
1972年 | 420篇 |
1971年 | 374篇 |
1970年 | 304篇 |
1969年 | 379篇 |
1968年 | 440篇 |
1967年 | 389篇 |
1966年 | 377篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
241.
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
242.
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
243.
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
244.
A new method for determining the minimum number of observations per subject needed to achieve a specific generalizability coefficient is presented. This method, which consists of a branch-and-bound algorithm, allows for the employment of constraints specified by the investigator. 相似文献
245.
Varieties of size-specific visual selection 总被引:1,自引:0,他引:1
Compared time to evaluate stimuli of varying sizes. When Ss expect an upcoming stimulus to be a certain size, response time increases with the disparity between expected and actual size. There are, however, 2 size adjustment processes, and they reflect 2 types of visual selection. In the first, a shape-specific image representation is used to separate a visual object from a superimposed distractor. These representations require the type of slow size scaling demonstrated in imagery experiments. The second size scaling process is faster and not shape-specific. At any given time the visual system is set to process information at a particular scale, and that scale can be adjusted to match an object's size. Because both selection mechanisms depend on size, they probably occur at a relatively low, spatially organized processing level. These findings lead to a new explanation for results that had been taken as evidence for attentional selection at the level of object representations. 相似文献
246.
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
247.
248.
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
249.
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
250.
K H Pollak 《Psychiatrie, Neurologie, und medizinische Psychologie》1989,41(11):664-679
154 autopsy cases of alcoholics (120 men and 34 women) were investigated from a neuropathological viewpoint. In only 19 cases could typical diseases of the nervous system caused by alcoholism be found (Wernicke's encephalopathy, central pontine myelinolysis, Marchiafava-Bignami's disease and disorders of the peripheral nerves and muscles). In comparison liver diseases occurred almost five times more frequently in our own material. Diseases caused by alcoholism of the nervous system, the question of brain shrinkage and its partial reversibility, the up to now not completely known effects on the neurophil and cortical cytoarchitectonic are discussed according to the literature. 相似文献