全文获取类型
收费全文 | 15427篇 |
免费 | 317篇 |
国内免费 | 193篇 |
出版年
2012年 | 1529篇 |
2011年 | 1691篇 |
2010年 | 381篇 |
2009年 | 193篇 |
2008年 | 1323篇 |
2007年 | 1251篇 |
2006年 | 1181篇 |
2005年 | 960篇 |
2004年 | 866篇 |
2003年 | 783篇 |
2002年 | 742篇 |
2001年 | 454篇 |
2000年 | 548篇 |
1999年 | 240篇 |
1998年 | 85篇 |
1997年 | 43篇 |
1996年 | 63篇 |
1995年 | 37篇 |
1994年 | 86篇 |
1993年 | 100篇 |
1992年 | 106篇 |
1991年 | 112篇 |
1990年 | 104篇 |
1989年 | 106篇 |
1988年 | 127篇 |
1987年 | 133篇 |
1986年 | 102篇 |
1985年 | 130篇 |
1984年 | 118篇 |
1983年 | 141篇 |
1982年 | 102篇 |
1981年 | 98篇 |
1980年 | 83篇 |
1979年 | 89篇 |
1978年 | 84篇 |
1966年 | 48篇 |
1965年 | 133篇 |
1964年 | 104篇 |
1963年 | 126篇 |
1962年 | 55篇 |
1958年 | 151篇 |
1957年 | 130篇 |
1956年 | 143篇 |
1955年 | 84篇 |
1954年 | 81篇 |
1953年 | 75篇 |
1952年 | 71篇 |
1951年 | 72篇 |
1950年 | 44篇 |
1949年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
261.
Resistance To Change As A Function Of Stimulus-reinforcer And Location-reinforcer Contingencies
下载免费PDF全文
![点击此处可从《Journal of the experimental analysis of behavior》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Pigeons responded on two keys in each component of a multiple concurrent schedule. In one series of conditions the distribution of reinforcers between keys within one component was varied so as to produce changes in ratios of reinforcer totals for key locations when summed across components. In a second series, reinforcer allocation between components was varied so as to produce changes in ratios of reinforcer totals for components, summed across key locations. In each condition, resistance to change was assessed by presenting response-independent reinforcers during intercomponent blackouts and (for the first series) by extinction of responding on both keys in both components. Resistance to change for response totals within a component was always greater for the component with the larger total reinforcer rate. However, resistance to change for response totals at a key location was not a positive function of total reinforcement for pecking that key; indeed, relative resistance to extinction for the two locations showed a weak negative relation to ratios of reinforcer totals for key location. These results confirm the determination of resistance to change by stimulus—reinforcer contingencies. 相似文献
262.
A review of the literature was conducted to better understand the (potential) role of mental health professionals in physician-assisted suicide. Numerous studies indicate that depression is one of the most commonly encountered psychiatric illnesses in primary care settings. Yet, depression consistently goes undetected and undiagnosed by nonpsychiatrically trained primary care physicians. Noting the well-studied link between depression and suicide, it is necessary to question giving sole responsibility of assisting patients in making end-of-life treatment decisions to these physicians. Unfortunately, the use of mental health consultation by these physicians is not a common occurrence. Greater involvement of mental health professionals in this emerging and debated area is advocated. Beyond describing mental health professionals' role in the assessment of patient competency or decision making capacity, other areas of potential involvement are described. A discussion of ethical principles relevant to this area follows, along with comments on the training necessary to adequately serve patient needs. 相似文献
263.
对人的尊严的挑战——试论P.辛格的优先权——实利主义 总被引:2,自引:0,他引:2
一个社会对其成员重视和承认的程度,首先表现为这个社会如何对待其成员中的弱者和受歧视的人。而在每个社会遭受歧视的人中,无疑也包括那些由于先天或后天的缘故患有精神上或肉体上的疾病而需要特别照顾的人。1989年以来,首先是这一社会群体的代言人,对他们的遭遇提出了强烈的抗议。而他们的抗议,又引发了德国舆论界对澳大利亚哲学家彼得·辛格的关注。特别是辛格关于可以对残疾人(既包括先天不足的婴儿,也包括老年人)施行强制性安乐死的论述,点燃了论战的烽火,更激起了一部分人的强烈抗议。残疾人的代盲人指出,辛格的“实用伦理学”不仅是对“残疾人”,而且从根本上讲是对人的错误认识。 相似文献
264.
265.
A theoretical analysis of the structure and dynamics of human motor functioning is presented from the perspective of a general theory of individuality. Within multifactor-systems theory, the structural units of the six systems of integrative personality (i.e., sensory, motor, cognitive, affect, style, and value) are hierarchical factor structures. Integrative functioning, both within and among systems, is described via the principles of general systems and information-processing theory. Our theoretical synthesis of the structure and dynamics of human motor functioning involves conceptualizing the hierarchy of motor factors as: (a) the basic dimensions of individual differences in the motor domain, (b) classes of decomposable motor programs that specify the spatio-temporal organization of behavior, and (c) decomposable classes of processing components entailed by motor programs. Some of the implications for understanding the role of affect in motor functioning and some research suggestions were presented. 相似文献
266.
267.
The relative law of effect: effects of shock intensity on response strength in multiple schedules 总被引:3,自引:3,他引:0
下载免费PDF全文
![点击此处可从《Journal of the experimental analysis of behavior》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Bouzas A 《Journal of the experimental analysis of behavior》1978,30(3):307-314
Key pecking of four birds was reinforced with food according to a two-component multiple variable-interval 1-minute variable-interval 4-minute schedule. In addition, key pecking was punished by a brief shock according to a variable-interval 30-second schedule during both components of the multiple schedule. The intensity of the shock was varied. For all birds, punishment had a stronger suppressive effect on the responding maintained by the leaner food schedule, and the ratio of responding during the two components of the multiple schedule became closer to the ratio of reinforcement as shock intensity was increased, as the relative law of effect predicts. At the higher shock intensity, there was some evidence that the ratio of responses overmatched the ratio of reinforcements. 相似文献
268.
The effects of different component response requirements in multiple and concurrent schedules 总被引:10,自引:10,他引:0
下载免费PDF全文
![点击此处可从《Journal of the experimental analysis of behavior》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Six pigeons were trained on multiple and concurrent schedules. The reinforcement rates were varied systematically (a) when lever pressing was required in one component and key pecking in the successive component; (b) when lever pressing was required in both multiple components; (c) when key pecking was required in both multiple components; and (d) when key pecking was required on one schedule and lever pressing was required on the concurrently-available schedule. Only the absolute level of responding was changed by different response requirements. Analyzed by the generalized matching law, performance under different response requirements resulted in a bias toward key pecking, and the measured response bias was the same in multiple and concurrent schedule arrangements. The bias in time measures obtained from concurrent schedule performance was reliably smaller than the obtained response biases. The sensitivity to reinforcement-rate changes was ordered: concurrent key-lever; multiple key-key; multiple lever-key; and, the least sensitive, multiple lever-lever. The results confirm that requirements of different topographical responses can be handled by the generalized matching law mainly in the bias parameter, but problems for this type of analysis may be caused by the changing sensitivity to reinforcement in multiple schedule performance as response requirements are changed. 相似文献
269.
270.