全文获取类型
收费全文 | 4568篇 |
免费 | 119篇 |
国内免费 | 23篇 |
出版年
2017年 | 7篇 |
2012年 | 448篇 |
2011年 | 525篇 |
2010年 | 125篇 |
2009年 | 52篇 |
2008年 | 434篇 |
2007年 | 471篇 |
2006年 | 390篇 |
2005年 | 341篇 |
2004年 | 284篇 |
2003年 | 297篇 |
2002年 | 260篇 |
2001年 | 166篇 |
2000年 | 234篇 |
1999年 | 83篇 |
1998年 | 39篇 |
1997年 | 23篇 |
1996年 | 13篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 9篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 10篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 14篇 |
1983年 | 16篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 13篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1976年 | 13篇 |
1975年 | 9篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1959年 | 9篇 |
1958年 | 31篇 |
1957年 | 20篇 |
1956年 | 19篇 |
1955年 | 26篇 |
1954年 | 13篇 |
1953年 | 20篇 |
1952年 | 22篇 |
1951年 | 18篇 |
1950年 | 17篇 |
1948年 | 8篇 |
排序方式: 共有4710条查询结果,搜索用时 15 毫秒
11.
Harzem P 《Journal of the experimental analysis of behavior》1984,42(3):385-395
In psychological studies individual differences that result in variability in data and thus mask the effects under investigation have been reduced or eliminated in two ways: (1) through the use of large numbers of subjects and statistical manipulations, or (2) through extensive and controlled studies of individual subjects. The latter, behavior-analytic, method is scientifically better because it permits identification of the variables that result in individual differences. This paper advocates the direct study of individual differences and personality rather than indirect study through experimental control procedures. Some data are presented showing that individual differences in response patterns have orderly characteristics. Extension of the experimental analysis of behavior to the study of individual differences and personality is likely to be important both scientifically and for the future growth of behavior analysis. 相似文献
12.
Killeen P 《Journal of the experimental analysis of behavior》1972,18(1):13-22
Pigeons were exposed to alternative pairs of variable-interval schedules correlated with red and green lights on one key (the food key). In one experimental chamber, responses on a white key (the changeover key) changed the color of the food key and initiated a 2-sec changeover delay. Pigeons in a second chamber obtained food by pecking on a colored key whenever the pigeons in the first (concurrent) chamber had obtained food for a peck on that key color. There was no changeover key in the second (multiple) chamber: changeover responses in the first chamber alternated the schedules and colors in both chambers. The pigeons in both chambers emitted the same proportion of responses on each of the variable-interval schedules, and mastered discrimination reversals at the same rate. The pigeons differed only in their absolute response rates, which were greater under the concurrent schedules. In a second experiment, changes in key color occurred automatically, with different proportions of time allocated to the two variable-interval schedules. Matching of relative response frequency to relative reinforcement frequency was affected by the relative amounts of time in each component, by rate of changeovers, and by manipulations of the variable-interval scheduling. 相似文献
13.
14.
15.
16.
17.
A literature search was conducted on studies of new drugs used with patients with schizophrenia reported by U.S. and non-U.S. researchers from 1966–1993, yielding 41 U.S., and a total of 24 other non-U.S. studies, among them 11 British studies. Results of the U.S. and non-U.S. studies were pooled separately and compared. Among several comparable conditions discussed, the lack of any data on suicides in the U.S. studies was observed. For a second statistical analysis of suicide rates ‘person-years’ were calculated to adjust for differing washout durations. The results obtained include findings that the percentage of patients relapsing in U.S. studies was slightly lower (37.9%) than in non-U.S. studies (46%); the percentage of patients dropping out in U.S. studies (10.5%) was higher than in non-U.S. studies (7.6%); known location of dropout patients in U.S. studies was 1.7%, compared to 2.6% in non-U.S. studies. The most interesting finding was that no suicides were reported in U.S. studies, compared to 0.6% of patients reported in British studies. Some U.S. studies used ‘challenge doses’, such as amphetamines or L-dopa; no non-U.S. studies reported their use. Compared to U.S. studies, those by non-U.S., and particularly British, researchers appeared to report adverse events in their studies. ‘Challenge’ drugs were not used; suicides were reported. It is estimated that the probability that no patients suicided who participated in the U.S. is small—one in 500. 相似文献
18.
19.
20.