全文获取类型
收费全文 | 42227篇 |
免费 | 1683篇 |
国内免费 | 14篇 |
专业分类
43924篇 |
出版年
2020年 | 414篇 |
2019年 | 470篇 |
2018年 | 681篇 |
2017年 | 673篇 |
2016年 | 740篇 |
2015年 | 545篇 |
2014年 | 615篇 |
2013年 | 2879篇 |
2012年 | 1200篇 |
2011年 | 1161篇 |
2010年 | 728篇 |
2009年 | 716篇 |
2008年 | 1036篇 |
2007年 | 1037篇 |
2006年 | 888篇 |
2005年 | 852篇 |
2004年 | 804篇 |
2003年 | 719篇 |
2002年 | 745篇 |
2001年 | 1377篇 |
2000年 | 1298篇 |
1999年 | 949篇 |
1998年 | 424篇 |
1992年 | 912篇 |
1991年 | 855篇 |
1990年 | 871篇 |
1989年 | 757篇 |
1988年 | 764篇 |
1987年 | 726篇 |
1986年 | 745篇 |
1985年 | 835篇 |
1984年 | 639篇 |
1983年 | 584篇 |
1982年 | 413篇 |
1981年 | 391篇 |
1980年 | 374篇 |
1979年 | 735篇 |
1978年 | 475篇 |
1977年 | 460篇 |
1976年 | 449篇 |
1975年 | 641篇 |
1974年 | 720篇 |
1973年 | 756篇 |
1972年 | 660篇 |
1971年 | 618篇 |
1970年 | 599篇 |
1969年 | 594篇 |
1968年 | 788篇 |
1967年 | 714篇 |
1966年 | 632篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
A simple histological technique for localizing electrode tracks and lesions within the brain. 总被引:1,自引:0,他引:1 下载免费PDF全文
Histological procedures are necessary in brain stimulation or lesion work to determine the neural area which has been stimulated or damaged. Preparation of brain tissue often involves embedding and staining techniques that require specialized training, and the expense of a technician and a large assortment of special apparatus and supplies. In addition, the results of such techniques are unavailable for at least several days. A photographic method, which requires little special skill and a minimal amount of apparatus, is described here. Results can be available within minutes after the subject is sacrificed. This method has been shown to be adequate for the gross determination of lesion boundaries and electrode or cannula tip loci in brains of rats, cats, and squirrel monkeys. 相似文献
912.
913.
914.
915.
916.
R B Anderson 《Sociometry》1967,30(2):124-136
917.
Pavlovian conditioning and its proper control procedures 总被引:14,自引:0,他引:14
R A Rescorla 《Psychological review》1967,74(1):71-80
918.
919.
In this paper we concern ourselves with the problem of whether or not conditioning stimuli of other modalities or stimuli applied to a distant locus of the body interact with a sensitive test of somesthetic temporal acuity we have called the gap test. The results of the experiment indicate that visual stimuli do not exert an observable influence on this temporal judgment, but that auditory stimuli and contralateral stimulation in the same modality do show a significant but relatively small effect. This is compared and contrasted with the very large and persistent effect reported when the conditioning stimulus is applied to the same electrodes as the gap test. By comparing our results with experiments of similar design carried out on lower animals by other investigators, some insights into the neural localization of the reported effects is obtained. 相似文献
920.
The Pulfrich pendulum was evaluated as a potential screening device for the detection of anomalies of binocular vision. For this purpose, a booth was set up at the Kentucky State Fair (1964) and the general public invited to observe the pendulum and record their responses with the equipment provided. The obtained results indicate that a dichotomy can be achieved between those who have binocular vision and those who do not. However, gradations of binocular vision from poor to good cannot be achieved with the pendulum as presently understood. Contrary to explanatory theory the characteristic shape of the seen pendulum path was asymmetrical following the rule that the path was displaced away from the observer on the side of the filtered eye. 相似文献