全文获取类型
收费全文 | 61773篇 |
免费 | 1690篇 |
国内免费 | 17篇 |
专业分类
63480篇 |
出版年
2020年 | 438篇 |
2019年 | 498篇 |
2018年 | 3977篇 |
2017年 | 3322篇 |
2016年 | 2878篇 |
2015年 | 741篇 |
2014年 | 701篇 |
2013年 | 2987篇 |
2012年 | 1738篇 |
2011年 | 3406篇 |
2010年 | 3126篇 |
2009年 | 2116篇 |
2008年 | 2632篇 |
2007年 | 3078篇 |
2006年 | 923篇 |
2005年 | 1066篇 |
2004年 | 968篇 |
2003年 | 831篇 |
2002年 | 797篇 |
2001年 | 1405篇 |
2000年 | 1351篇 |
1999年 | 961篇 |
1998年 | 444篇 |
1997年 | 393篇 |
1992年 | 915篇 |
1991年 | 858篇 |
1990年 | 879篇 |
1989年 | 757篇 |
1988年 | 766篇 |
1987年 | 728篇 |
1986年 | 747篇 |
1985年 | 837篇 |
1984年 | 640篇 |
1983年 | 585篇 |
1982年 | 412篇 |
1981年 | 392篇 |
1979年 | 736篇 |
1978年 | 475篇 |
1977年 | 462篇 |
1976年 | 453篇 |
1975年 | 641篇 |
1974年 | 722篇 |
1973年 | 759篇 |
1972年 | 662篇 |
1971年 | 618篇 |
1970年 | 599篇 |
1969年 | 595篇 |
1968年 | 786篇 |
1967年 | 713篇 |
1966年 | 631篇 |
排序方式: 共有10000条查询结果,搜索用时 6 毫秒
981.
982.
Role of contextual discrimination in fear conditioning 总被引:1,自引:0,他引:1
983.
984.
985.
986.
987.
988.
989.
Past studies have shown that stuttering is eliminated when speech is synchronized with a metronomic beat, but the speech sounds artificial. The present study investigated the effect of increasing the duration of these individual stimulus beats with the stimulus-off period constant at 1 sec. When subjects were instructed to speak during the stimulus-on period, stuttering was an inverse function of stimulus duration, indicating that the known metronome effect on stuttering is one point on a continuum of effective rhythm procedures. The "naturalness" of speech increased as the stimulus duration increased up to durations of about 2 sec, and then decreased. At optimal values, stuttering was greatly reduced and naturalness and rapidity of speech were retained. These optimal values effectively controlled stuttering in a field test that used two types of specially designed portable instruments, one of which produced a tactual stimulus and the other an auditory stimulus. 相似文献
990.
The study attempted to isolate some of the environmental conditions that controlled the self-destructive behavior of three severely retarded and psychotic children. In the extinction study subjects were placed in a room where they were allowed to hurt themselves, isolated from interpersonal contact. They eventually ceased to hurt themselves in that situation, the rate of self-destruction falling gradually over successive days. In the punishment study, subjects were administered painful electric shock contingent on the self-destructive behavior. (1) The self-destructive behavior was immediately suppressed. (2) The behavior recurred when shock was removed. (3) The suppression was selective, both across physical locales and interpersonal situations, as a function of the presence of shock. (4) Generalized effects on other, non-shock behaviors, appeared in a clinically desirable direction. Finally, a study was reported where self-destructive behavior increased when certain social attentions were given contingent upon that behavior. 相似文献