全文获取类型
收费全文 | 1260篇 |
免费 | 172篇 |
国内免费 | 22篇 |
出版年
2024年 | 1篇 |
2023年 | 42篇 |
2022年 | 6篇 |
2021年 | 29篇 |
2020年 | 55篇 |
2019年 | 73篇 |
2018年 | 69篇 |
2017年 | 57篇 |
2016年 | 69篇 |
2015年 | 37篇 |
2014年 | 44篇 |
2013年 | 146篇 |
2012年 | 21篇 |
2011年 | 23篇 |
2010年 | 34篇 |
2009年 | 44篇 |
2008年 | 64篇 |
2007年 | 78篇 |
2006年 | 78篇 |
2005年 | 71篇 |
2004年 | 53篇 |
2003年 | 30篇 |
2002年 | 45篇 |
2001年 | 24篇 |
2000年 | 38篇 |
1999年 | 37篇 |
1998年 | 21篇 |
1997年 | 27篇 |
1996年 | 9篇 |
1995年 | 20篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 10篇 |
1991年 | 14篇 |
1990年 | 16篇 |
1989年 | 7篇 |
1988年 | 12篇 |
1987年 | 7篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 3篇 |
排序方式: 共有1454条查询结果,搜索用时 15 毫秒
991.
Abstract. Fritjof Capra's The Tao of Physics , one of several popularizations paralleling Eastern mysticism and modern physics, is critiqued, demonstrating that Capra gives little attention to the differing philosophies of physics he employs, utilizing whatever interpretation suits his purposes, without prior justification. The same critique is applied and similar conclusions drawn, about some recent attempts at relating theology and physics. In contrast, we propose the possibility of maintaining a cogent relationship between these disciplines by employing theological hypotheses to account for aspects of physics that are free from interpretive difficulties, such as the ability to create mathematical structures with extraordinary predictive success. 相似文献
992.
Pigeons, trained to discriminate phencyclidine from saline under a procedure requiring the bird to track the location of a color, received cumulative doses of phencyclidine, pentobarbital, or d-amphetamine with a variety of schedules of reinforcement in effect (across phases). When the same second-order schedules were used to reinforce responding after either saline or phencyclidine administration, stimulus control by phencyclidine did not depend on the schedule parameter. When different second-order schedules were used that biased responding toward the phencyclidine-correlated key color, pigeons responded on the phencyclidine-correlated key at lower doses of phencyclidine and pentobarbital than when the second-order schedule biased responding toward the saline key color. A similar but less marked effect was obtained with d-amphetamine. Attempts to produce bias by changing reinforcement magnitude (duration of food availability) were less successful. A signal-detection analysis of dose-effect curves for phencyclidine under two of the second-order schedules employed suggested that at low doses of phencyclidine, response bias is a major determinant of responding. As doses were increased, position preferences occurred and response bias decreased; at higher doses both response bias and position preference decreased and discriminability increased. With low doses of pentobarbital, responding again was biased but increasing doses produced position preference with only small increases in discriminability. At low doses of d-amphetamine responding also was biased, but bias did not decrease consistently with dose nor did discriminability increase. These experiments suggest that the schedule of reinforcement can be used to bias responding toward or away from making the drug-correlated response in drug discrimination experiments, and that signal-detection analysis and analysis of responding at a position can be used to separate the discriminability of the drug state from other effects of the drug on responding. 相似文献
993.
P K Corfield-Sumner D E Blackman G Stainer 《Journal of the experimental analysis of behavior》1977,27(2):265-273
Three rats were exposed to a second-order schedule in which fixed-interval components ended either with food or with a brief stimulus that was never paired with food. Food and the brief stimulus occurred in a random sequence (variable-ratio 2 overall schedule). Another three rats were exposed to a similar second-order schedule, the only difference being that the food or the stimulus was presented independently of operant behavior (fixed-time components). The three rats exposed to the fixed-interval components licked at a water spout after each food presentation. These rats also licked in the intervals after the brief stimulus. Although the discriminative properties of food and of the brief stimulus were identical in relation to subsequent reinforcement, licking after the stimulus was less than after food. The three rats exposed to the second-order schedules with fixed-time components also licked at the water spout after food, but these rats did not lick consistently after brief stimulus presentations. 相似文献
994.
Richard Busse 《Zygon》1998,33(1):131-145
Historian James Gilbert argues that the dialogue between science and religion is an important dynamic in the creation of contemporary American culture. He traces the dialogue not only in the confines of the academic world but also in popular culture. The science-religion dialogue reveals a basic tension between the material and the spiritual that helps define the core of the American psyche: fascination with material progress yet commitment to traditional religious beliefs. Gilbert's cultural narrative traces the dialogue in a unique way because of the attention given to popular renditions of science and religion in evangelical films used by the military, in televised science programs, in science-fiction literature, and at the Seattle World's Fair in 1962. Gilbert suggests that the discussion between science and religion is significant because it is part of the process of creating new cultural structures necessitated by social, scientific, and technological developments. The tensions between religiously informed commonsense science and professional science work to create new cultural forms in a democratic society. Religion and science in dialogue are part of the process of cultural creation. Dogmatism on the part of either scientists or religionists is countered by the democratic process itself. 相似文献
995.
996.
现代医学的时代特征与医学的应当 总被引:5,自引:1,他引:4
王国领 《医学与哲学(人文社会医学版)》1998,19(10):516-518
21世纪的医学将真正从生物医学发展为人的医学,医学文化将是科学文化与人文文化的统一,医学将更加社会化,国际化,信息化,市场化,生态伦理化和多元化,医学目的也必将多元化。医学是时代的医学,但医学在走向人学。 相似文献
997.
The ideal of scientific openness — i.e. the idea that scientific information should be freely accessible to interested parties — is strongly supported throughout the scientific community. At the same time, however, this ideal does not appear to be absolute in the everyday practice of science. In order to get the credit for new scientific advances, scientists often keep information to themselves. Also, it is common practice to withhold information obtained in commissioned research when the scientist has agreed with his or her employer to do so. The secrecy may be intended for ever, as in the military area, but also temporarily until a patent application has been made. The paper explores to what extent such secrecy is undesirable, as seems to be suggested by the ideal of scientific openness. Should this ideal be interpreted as having certain exceptions which make the above-mentioned practices acceptable? Are there, on closer inspection, good arguments for the ideal of scientific openness, and for officially upholding it? Possible versions of the ideal of scientific openness are explored and the issue is found to be rather complex, allowing for wide variations depending on the acting parties, beneficiaries, types of information and moral requirements involved. We conclude that the arguments usually given in favour of this ideal are weaker than what seems to be generally believed, and that, on closer inspection, they leave plenty of room for exceptions to it. These exceptions only partly cover the actual practice of withholding scientific information, and there may still be good reason to advocate, teach and enforce the ideal of scientific openness within the scientific community. 相似文献
998.
Second-order schedules of token reinforcement: comparisons of performance under fixed-ratio and variable-ratio exchange schedules 总被引:4,自引:4,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)
Rats' lever pressing produced tokens according to a 20-response fixed-ratio schedule. Sequences of token schedules were reinforced under a second-order schedule by presentation of periods when tokens could be exchanged for food pellets. When the exchange period schedule was a six-response fixed ratio, patterns of completing the component token schedules were bivalued, with relatively long and frequent pauses marking the initiation of each new sequence. Altering the exchange period schedule to a six-response variable ratio resulted in sharp reductions in the frequency and duration of these initial pauses, and increases in overall rates of lever pressing. These results are comparable to those ordinarily obtained under simple fixed-ratio and variable-ratio schedules. 相似文献
999.
The article gives a short account of V.A. Smirnovs scientific biography, including his work in Tomsk University in Siberia and in the Department of Logic of the Institute of Philosophy in Moscow. 相似文献
1000.
Spanier B 《Science and engineering ethics》2000,6(4):467-480
Feminist contributions to the science curricula in higher education constitute invaluable but often overlooked resources for
truly effective communication about science. Here I share a sampling of feminist science studies and discuss the origins of
this effort to create inclusive and less biased science curricula that serve all students and citizens. Challenges from scientists
center on assumptions and values about the appropriate relationship between science and politics, while challenges from educators
extend to assumptions about how science has been taught. Currently, national and local curriculum transformation efforts are
producing useful insights and materials.
I want to thank Jinnie Garrett for inviting me to participate in the very exciting conference (Communicating Science held
at Hamilton College, Clinton, NY, USA, 3–5 October 1998) and for her encouragement in preparing this paper. I also want to
thank Joan Schulz and Patricia Brown for the important discussions and assistance contributing to this work. 相似文献