全文获取类型
收费全文 | 14681篇 |
免费 | 614篇 |
国内免费 | 13篇 |
出版年
2023年 | 74篇 |
2021年 | 131篇 |
2020年 | 229篇 |
2019年 | 275篇 |
2018年 | 382篇 |
2017年 | 385篇 |
2016年 | 398篇 |
2015年 | 277篇 |
2014年 | 357篇 |
2013年 | 1627篇 |
2012年 | 634篇 |
2011年 | 689篇 |
2010年 | 409篇 |
2009年 | 447篇 |
2008年 | 597篇 |
2007年 | 592篇 |
2006年 | 593篇 |
2005年 | 543篇 |
2004年 | 516篇 |
2003年 | 523篇 |
2002年 | 511篇 |
2001年 | 269篇 |
2000年 | 245篇 |
1999年 | 254篇 |
1998年 | 223篇 |
1997年 | 230篇 |
1996年 | 206篇 |
1995年 | 188篇 |
1994年 | 177篇 |
1993年 | 174篇 |
1992年 | 158篇 |
1991年 | 170篇 |
1990年 | 148篇 |
1989年 | 129篇 |
1988年 | 94篇 |
1987年 | 125篇 |
1986年 | 135篇 |
1985年 | 170篇 |
1984年 | 169篇 |
1983年 | 143篇 |
1982年 | 134篇 |
1981年 | 148篇 |
1980年 | 131篇 |
1979年 | 110篇 |
1978年 | 127篇 |
1977年 | 114篇 |
1976年 | 112篇 |
1975年 | 102篇 |
1974年 | 114篇 |
1973年 | 93篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
211.
212.
David R. Thomas William Klipec Joseph Lyons 《Journal of the experimental analysis of behavior》1966,9(5):567-571
In two separate experiments, pigeons trained binocularly to peck a key on which an oblique line (e.g., 60 degrees counter-clockwise rotation from horizontal) was projected yielded bi-modal angularity generalization gradients in extinction, with peaks of responding at both the training stimulus and its mirror image (in this case 120 degrees ). This mirror-image transfer effect may be analogous to an "octave effect" in auditory generalization, but Mello's finding of a mirror-image reversal transfer effect following monocular training in pigeons suggests an alternative interpretation. 相似文献
213.
214.
David D. Clark 《Journal of counseling and development : JCD》1966,44(8):817-823
Factual and subjective data gathered from counseling centers in 36 major universities is presented to show present conditions, emphasis, and needs of the future. Data are presented showing ratios of counselors to students, budget allotments, strengths, specific weaknesses, etc. Counseling facilities, services provided, emphasis, communications and plans for expansion are dealt with individually. Less than half the centers were meeting student needs and a majority indicated a shortage of professional staff, particularly those competent to do personal adjustment counseling. 相似文献
215.
Some previous publications have indicated that the creative skills of chemists tend to decline once they are past their thirties or early forties. These conclusions have been based on such criteria of creativity as merit ratings, citations in the literature, etc. In the present study, patent records for all 89 professional men (mostly chemists and chemical engineers) in one division of a large industrial scientific organization were analyzed to determine whether creativity as measured by the production of patentable ideas tended to decrease with age, to increase, or to remain about the same. In the statistical treatment of data both longitudinal and cross-sectional methods were used. All the results were consistent in revealing no decline in creative productivity with increase in age, and indicated instead a tendency for productivity to increase as chemists mature. 相似文献
216.
David V. Budescu Thomas S. Wallsten 《Organizational behavior and human decision processes》1990,46(2)
The goal of the research was to compare decisions under risk in a situation in which forecasters (F) communicate to decision makers (DM) either numerically (e.g., .70) or verbally (e.g., likely) about the chances that a binary event will occur. Following each forecast, the DM bid for a winning or losing lottery based on the event. In Experiment 1 Fs and DMs also provided numerical translations of each verbal forecast after the DMs' bid. In Experiment 2 the DMs provided membership functions over the [0, 1] interval for each phrase used by the Fs. The primary results were: (a) extreme similarity in the DM's bids and rates of bidding under the two modes of communication; (b) greater variability in bids to specific verbal than numerical forecasts; (c) a pattern of bids, in which DMs demonstrated risk seeking for gains and risk neutrality for losses; (d) DMs' numerical translations in Experiment 1 were closer to .50 than were those of Fs; and (e) phrases selected by Fs had high membership values to DMs for the probabilities the Fs were attempting to describe. Points (a), (b), (d), and (e) are consistent with the ν-μ model which assumes that the vague meaning of a probability phrase can be represented by a membership function over the [0, 1] interval, and that in reaching a decision the DM focuses on a range of probabilities with sufficiently high membership. Point (c) is speculatively attributed to social aspects of the dyadic situation, and requires further investigation. 相似文献
217.
218.
219.
What we usually think of as higher order skills in argumentation can be profitably viewed as systematic structures for organizing and representing information. Standard terms like line of argument, synthesis, analysis and draft can be viewed as ways of constructing, storing, and accessing data in a social context — data structures for social communication. What makes argument difficult are the multiple structures that arguers have to construct and negotiate when reading and composing. In this paper, we describe the WARRANT project, a project designed to identify data structures of written argument and to design and implement computer tools to aid in the reading and design of argument. 相似文献
220.
The statistical simulation program DATASIM is designed to conduct large-scale sampling experiments on microcomputers. Monte Carlo procedures are used to investigate the Type I and Type II error rates for statistical tests when one or more assumptions are systematically violated-assumptions, for example, regarding normality, homogeneity of variance or covariance, mini-mum expected cell frequencies, and the like. In the present paper, we report several initial tests of the data-generating algorithms employed by DATASIM. The results indicate that the uniform and standard normal deviate generators perform satisfactorily. Furthermore, Kolmogorov-Smirnov tests show that the sampling distributions ofz, t, F, χ2, andr generated by DATASIM simulations follow the appropriate theoretical distributions. Finally, estimates of Type I error rates obtained by DATASIM under various patterns of violations of assumptions are in close agreement with the results of previous analytical and empirical studies; These converging lines of evidence suggest that DATASIM may well prove to be a reliable and productive tool for conducting statistical simulation research. 相似文献