全文获取类型
收费全文 | 16095篇 |
免费 | 619篇 |
国内免费 | 4篇 |
专业分类
16718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 | 261篇 |
2013年 | 1272篇 |
2012年 | 432篇 |
2011年 | 486篇 |
2010年 | 289篇 |
2009年 | 312篇 |
2008年 | 413篇 |
2007年 | 441篇 |
2006年 | 421篇 |
2005年 | 343篇 |
2004年 | 372篇 |
2003年 | 334篇 |
2002年 | 329篇 |
2001年 | 451篇 |
2000年 | 510篇 |
1999年 | 342篇 |
1998年 | 205篇 |
1997年 | 154篇 |
1996年 | 166篇 |
1995年 | 164篇 |
1992年 | 276篇 |
1991年 | 285篇 |
1990年 | 296篇 |
1989年 | 276篇 |
1988年 | 267篇 |
1987年 | 234篇 |
1986年 | 246篇 |
1985年 | 259篇 |
1984年 | 191篇 |
1983年 | 207篇 |
1982年 | 158篇 |
1980年 | 156篇 |
1979年 | 248篇 |
1978年 | 216篇 |
1977年 | 150篇 |
1975年 | 215篇 |
1974年 | 242篇 |
1973年 | 268篇 |
1972年 | 225篇 |
1971年 | 210篇 |
1970年 | 162篇 |
1969年 | 195篇 |
1968年 | 248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 15 毫秒
261.
M. B. Sterman J. J. Lynch M. T. Orne D. Paskewitz J. Costello N. Nicolov O. Diankov M. Popova E. Tsvetanska Robert G. Grenell J. J. Izquierdo V. H. Mark Joseph Germana N. Zill William P. Paré Joseph E. O. Newton George C. Offutt Walter Ehrlich Joseph E. D. Newton Julij Tosef J. Perez-Cruet Chester R. Wilpizeski John F. Lontz Andrew Livingston Joseph W. Cullen Samuel A. Corson Herman R. Weed Elizabeth O. Corson O. D. Murphree Paul N. Morgan Ruth Jarman J. Antal T. A. Ban J. V. Ananth H. E. Lehmann A. Ulric Moore Richard H. Barnes Wilson G. Pond 《Integrative psychological & behavioral science》1970,5(3):185-193
262.
Nine subjects, 14 to 18 yr old, pulled a knob on a schedule of monetary reinforcement. Concurrently, they escaped or avoided periodic presentations of a tone by pressing a button that required 1.5 lb (6.67 N) of force or by punching a padded cushion that required 20 lb (88.96 N) of force. The punching response was designated as an aggressive response because the force of this response together with its topography was comparable to responses of humans that deface objects and produce escape or counter aggression from other humans. It was found that button pressing was the preferred concurrent avoidance response and there were few punches. However, when the monetary reinforcer was discontinued (extinction) punching increased for seven of the nine subjects, but there was no consistent change in the rate of button pressing. When the punching response was replaced by another non-preferred but non-aggressive response, neither this response nor button pressing increased during extinction. Hence, the increase in punching during extinction cannot be attributed solely to the fact that it was a concurrent response or a non-preferred response. 相似文献
263.
The effect of a fading procedure upon the acquisition of control by an overshadowed auditory feature 下载免费PDF全文
Pigeons' key-pecking responses were reinforced in the presence of a compound stimulus that consisted of an auditory feature (a tone) and a visual feature (a light) and non-reinforced in the presence of a compound stimulus that was either a noise and a dark key, or noise and a light. In the condition where reinforcement trials differed from non-reinforcement trials on the basis of both auditory and visual features, the tone exerted very little control over responding on test. In the condition where reinforcement differed from non-reinforcement trials solely on the basis of the auditory features, an abrupt and a gradual introduction of the visual feature of the negative stimulus, a light, were compared for their effect upon control in the compounds. The tone acquired strong control in both cases. Evidence indicated that the tone had acquired control in the gradual condition without the occurrence of responses to the negative stimulus. An incidental finding was that when the negative stimulus consisted of a noise and a light, which was introduced abruptly, responding over the light dimension with tone, on test, was peaked at a point other than that light value used as positive and negative during training. 相似文献
264.
A free-operant avoidance schedule was used to establish and maintain foot-treadle responding by two Homing, one White King, and two Carneaux pigeons. In the absence of responding, the interval between shocks equaled 10 sec. Each time a treadle response occurred the shock was postponed for 32 sec. Pigeons appear to learn the treadle response more quickly and use it to avoid shock more successfully than do rats bar pressing on similar schedules. The treadle response becomes highly stereotyped and interresponse time distributions obtained from terminal behavior appear very similar to data obtained from rats. It is concluded that the difficulty in training pigeons to avoid electric shock is not in establishing avoidance behavior but in attempting to evaluate such behavior with the key-peck response. 相似文献
265.
The impact of professional negotiations on the current educational scene is examined and related to clarification of the school counselor role. Role confusion continues in the school situation, and negotiations may well be the way to bring about a change in the status quo. Negotiations for counselors are explored from the standpoints of dimensions of negotiations, implementation of negotiations, and attitude of professional associations. Conclusions are that negotiations have significant implications for counselor role delineation. 相似文献
266.
WILLIAM F. BRAZZIEL 《Journal of counseling and development : JCD》1970,48(9):747-751
The gap between black and white in college enrollment is widening. The guidance counselor plays a key role in the drive to eliminate the differences between the races in preparation for college and to secure the scholarships and grants necessary for enrollment. Comparability in enrollment means about 850,000 black students on college campuses; about 400,000 are there now. Comparability in 1976 will mean about a million black students enrolled. Master Counselors are required for this job, both to work with the children and to press for more federal aid in this area. 相似文献
267.
Effect of repetitive infant-infant separation of young monkeys 总被引:1,自引:0,他引:1
268.
269.
270.