全文获取类型
收费全文 | 16346篇 |
免费 | 506篇 |
国内免费 | 7篇 |
专业分类
16859篇 |
出版年
2023年 | 67篇 |
2021年 | 122篇 |
2020年 | 217篇 |
2019年 | 252篇 |
2018年 | 441篇 |
2017年 | 400篇 |
2016年 | 544篇 |
2015年 | 328篇 |
2014年 | 361篇 |
2013年 | 1358篇 |
2012年 | 803篇 |
2011年 | 795篇 |
2010年 | 423篇 |
2009年 | 439篇 |
2008年 | 613篇 |
2007年 | 589篇 |
2006年 | 539篇 |
2005年 | 1693篇 |
2004年 | 1093篇 |
2003年 | 849篇 |
2002年 | 540篇 |
2001年 | 205篇 |
2000年 | 204篇 |
1999年 | 209篇 |
1998年 | 192篇 |
1997年 | 160篇 |
1996年 | 110篇 |
1995年 | 149篇 |
1994年 | 154篇 |
1993年 | 133篇 |
1992年 | 148篇 |
1991年 | 152篇 |
1990年 | 167篇 |
1989年 | 150篇 |
1988年 | 136篇 |
1987年 | 148篇 |
1986年 | 122篇 |
1985年 | 130篇 |
1984年 | 141篇 |
1983年 | 116篇 |
1982年 | 113篇 |
1981年 | 116篇 |
1980年 | 104篇 |
1979年 | 134篇 |
1978年 | 119篇 |
1977年 | 96篇 |
1976年 | 103篇 |
1975年 | 92篇 |
1974年 | 108篇 |
1973年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Michael E. Mills 《Behavior research methods》1992,24(2):321-325
GRADER, a computer program that makes student test and/or course letter grade recommendations to instructors, is described. The program uses an algorithm to combine the content mastery (percentage correct) and peer comparison (“curve”) approaches to set grade cutoffs. In addition to standardizing the procedures with which letter grade cutoffs are made, GRADER may help to reduce instructor grading subjectivity and obviate tendencies toward grade inflation or deflation. 相似文献
72.
Clint Bowers Eduardo Salas Carolyn Prince Michael Brannick 《Behavior research methods》1992,24(4):503-506
Teams are playing an increasingly important role in the workplace. However, reviews of the team performance literature have suggested that there are serious deficiencies in our understanding of team processes and performance (e.g., Dyer, 1984). These difficulties may be attributable, in part, to the lack of laboratory methodologies to investigate team performance. This paper describes the use of low-fidelity simulations as a potentially useful paradigm for researching team coordination and performance. This paradigm is advantageous in that it offers relatively high levels of experimental control and task representation at a low cost. 相似文献
73.
74.
H H?fner 《Psychiatrie, Neurologie, und medizinische Psychologie》1989,41(8):449-475
Since more than one century suicides have been registered in national statistics of death causes. They thus furnish one of the few parameters of psychiatrically relevant behaviour by means of which trends, cohort, age-group and period effects can be studied over longer periods. Since the second half of last century, the suicide rates for Swiss males--similar to those found in England and Wales--show a decrease in consecutive birth cohorts up to males born in the decade 1930-1940, and a continued decline in the total trend until about World War II. From then on the suicide rates of males in consecutive birth cohorts have been slowly increasing in the majority of European and North American countries--but not so in Sweden. Opposite to this, the predominantly low rates for females display little change. Further to the considerable differences between nations and the predominance of suicides committed by females in some Asian countries and Cuba, the changes indicate the significance of cultural and economic environmental factors. Typical period effects are mainly the result of changes in conception and conditions of life. In attempted suicide they proceed in a more sensitive and more rapid way and are about ten times higher. Such a period effect showing increases by about 300% in younger age-groups followed by a decline, attaining its peak about 1976, was ascertained in large cities of the Federal Republic of Germany. By the example of the effects of a television serial, the study of causal processes turning collective environmental factors into individual suicidal behaviour, proved that regularities are effective in learning by a process of modelling. Besides, the epidemiological data give essential hints how to treat suicidal behaviour. 相似文献
75.
The initial results of a German-Swedish research project demonstrate the at times active-resistant and at times passive-resigned approaches of AIDS patients toward their illness. 相似文献
76.
To assess temporal variations in the perception of "phasic" heat pain stimuli a psychophysical tracking procedure was developed that enables repeated assessment of the pain threshold at short intervals. This "double-tracking" procedure produces two tracking curves simultaneously, one that approaches the pain threshold gradually from above, the other from below. The threshold for phasic heat pain was measured in 80 tracking trials with stimuli at temperatures near the pain threshold. Concurrently, the threshold for "tonic" heat pain was determined after every 20 tracking trials with a stimulus adjustment procedure. Eleven healthy subjects (age: 26.4 yr. +/- 6.0) participated in 2 sessions each. Phasic stimulation near the pain threshold did not produce any trends in either of the two threshold measures. Hence there was no long-term adaptation or sensitization. However, there were random variations (random walks) in the tracking curves, which we interpret as resulting from a stochastic relationship between stimulus and sensation. In agreement with other reports, discrimination seemed to be better at painful than at nonpainful temperatures. 相似文献
77.
Choice reaction time involves, at least two components of response latency, decision time and movement time. Studies of choice reaction time usually provide values of these two components averaged over a given number of trials. The aim of the present study of depressed subjects was to investigate changes across practice on Decision Time (DT) and Movement Time (MT) before and after clinical improvement. 19 depressed subjects were given two sessions of 50 trials each, one before treatment (Di) and one after recovery (Df). Decision time and movement time exhibited quite different patterns. Decision time significantly decreased with clinical improvement. No significant variation across trials was found, in either session. Movement time values varied across trials but the variations observed on Di and Df were significantly different, whereas before treatment latencies recorded at the end of the session were greater than those scored at the start, the contrary was observed after clinical recovery. No significant difference was found between values of movement time scored at the start of the two sessions. 相似文献
78.
79.
Three experiments were designed to investigate the influence of initial recall on memory by assessing delayed recall after different immediate cued-recall tests. In all experiments, subjects performed semantic and phonemic encoding tasks on a word list. The subjects then received a cued-recall test that cued the target using the same word as the context word in the encoding task, a test that cued the target with a word from the same level at which the target was encoded, a test that cued the target with a cue from a different level at which the target was encoded, or no immediate-recall test. One day later, the subjects performed a final cued-recall test in which the type of cue (semantic or phonemic) was varied. Consistently, delayed recall was facilitated primarily when the cue on the immediate test was from the same level as the cue on the delayed test. This pattern of facilitation suggests that immediate cued-recall produces an elaboration of an existing memory representation that is closely tied to the type of cue used on the immediate test. 相似文献
80.
Susan M. Garnsey Michael K. Tanenhaus Robert M. Chapman 《Journal of psycholinguistic research》1989,18(1):51-60
Evoked brain potentials were used to monitor moment-by-moment decisions during language comprehension. Subjects read sentences containing temporary syntactic ambiguities for which one of the possible interpretations was semantically implausible. The N400 component of the evoked potential, which is sensitive to implausibility, was used to discover when during a sentence subjects made a decision about the ambiguity. The results demonstrate that readers try to interpret a syntactic ambiguity early in a sentence rather than waiting for disambiguating information. This introduces a new way to use brain activity to study sentence comprehension processes. 相似文献