全文获取类型
收费全文 | 51271篇 |
免费 | 1989篇 |
国内免费 | 20篇 |
专业分类
53280篇 |
出版年
2020年 | 528篇 |
2019年 | 725篇 |
2018年 | 931篇 |
2017年 | 979篇 |
2016年 | 1016篇 |
2015年 | 696篇 |
2014年 | 914篇 |
2013年 | 4041篇 |
2012年 | 1602篇 |
2011年 | 1669篇 |
2010年 | 1061篇 |
2009年 | 1027篇 |
2008年 | 1469篇 |
2007年 | 1517篇 |
2006年 | 1376篇 |
2005年 | 1193篇 |
2004年 | 1171篇 |
2003年 | 1085篇 |
2002年 | 1090篇 |
2001年 | 1536篇 |
2000年 | 1529篇 |
1999年 | 1146篇 |
1998年 | 557篇 |
1997年 | 507篇 |
1996年 | 486篇 |
1995年 | 495篇 |
1994年 | 475篇 |
1992年 | 964篇 |
1991年 | 882篇 |
1990年 | 950篇 |
1989年 | 834篇 |
1988年 | 855篇 |
1987年 | 793篇 |
1986年 | 801篇 |
1985年 | 774篇 |
1984年 | 667篇 |
1983年 | 653篇 |
1982年 | 483篇 |
1979年 | 779篇 |
1978年 | 589篇 |
1975年 | 644篇 |
1974年 | 711篇 |
1973年 | 753篇 |
1972年 | 578篇 |
1971年 | 576篇 |
1970年 | 492篇 |
1969年 | 571篇 |
1968年 | 699篇 |
1967年 | 644篇 |
1966年 | 539篇 |
排序方式: 共有10000条查询结果,搜索用时 6 毫秒
971.
972.
973.
974.
975.
976.
Nature of love--simplified 总被引:1,自引:0,他引:1
977.
Peter F. Galvani 《Behavior research methods》1970,2(5):232-233
In the first of two experiments, it was demonstrated that an air puff elicited a reliable startle reflex in rats which showed no habituation over 50 trials. In the second study an attempt was made to measure an emotional response by recording startle reactions to the air puff during presentation of a presumed fear-eliciting CS. It was concluded that the air-puff-elicited startle reflex can be employed as an indirect measure of a hypothetical emotional response. 相似文献
978.
Lawrence L. Feth 《Behavior research methods》1970,2(4):169-171
A noise generator that is capable of delivering long-duration samples of reproducible noise is described. The noise is generated as a pseudorandom telegraph waveform but may be filtered so that its amplitude distribution is approximately Gaussian. The design and construction of the generator are detailed and a few possible applications are given. 相似文献
979.
A semiautomatic version of the Wisconsin General Test Apparatus is described along with circuitry. Comparison data are provided for the semiautomatic and manual WGTA obtained under comparable procedures and conditions. Response latencies are given for go/no-go object discrimination problems and subsequent retention tests. 相似文献
980.
The electromyogram (EMG) recorded with surface electrodes was examined using a triggered oscilloscope technique. When all but the high-amplitude waveforms in a given segment of activity were excluded from analysis, it was found that the duration of the remaining waveforms was specific to the muscle that produced them. That is, waveforms of a given duration were recorded whenever conventional indices-observable contraction, joint movement. needle recordings-showed activity in a specific muscle. This led to the suggestion that waveform duration might be used to validate the surface EMG. The suggestion. which is limited by the need to control posture and electrode placement, both of which may influence waveform duration, was illustrated in application to psychological research. 相似文献