全文获取类型
收费全文 | 4574篇 |
免费 | 57篇 |
国内免费 | 10篇 |
专业分类
教育 | 3428篇 |
科学研究 | 241篇 |
各国文化 | 43篇 |
体育 | 406篇 |
综合类 | 3篇 |
文化理论 | 62篇 |
信息传播 | 458篇 |
出版年
2022年 | 27篇 |
2021年 | 44篇 |
2020年 | 59篇 |
2019年 | 112篇 |
2018年 | 141篇 |
2017年 | 151篇 |
2016年 | 147篇 |
2015年 | 99篇 |
2014年 | 120篇 |
2013年 | 937篇 |
2012年 | 131篇 |
2011年 | 130篇 |
2010年 | 151篇 |
2009年 | 135篇 |
2008年 | 148篇 |
2007年 | 144篇 |
2006年 | 109篇 |
2005年 | 95篇 |
2004年 | 99篇 |
2003年 | 81篇 |
2002年 | 96篇 |
2001年 | 66篇 |
2000年 | 107篇 |
1999年 | 74篇 |
1998年 | 74篇 |
1997年 | 63篇 |
1996年 | 74篇 |
1995年 | 57篇 |
1994年 | 67篇 |
1993年 | 64篇 |
1992年 | 49篇 |
1991年 | 71篇 |
1990年 | 51篇 |
1989年 | 47篇 |
1988年 | 37篇 |
1987年 | 45篇 |
1986年 | 45篇 |
1985年 | 43篇 |
1984年 | 47篇 |
1983年 | 39篇 |
1982年 | 31篇 |
1981年 | 35篇 |
1980年 | 30篇 |
1979年 | 24篇 |
1978年 | 32篇 |
1977年 | 38篇 |
1976年 | 27篇 |
1975年 | 22篇 |
1974年 | 23篇 |
1972年 | 14篇 |
排序方式: 共有4641条查询结果,搜索用时 15 毫秒
951.
Stephen J. Gaioni Howard S. Hoffman Peter DePaulo Valerie Newby Stratton 《Learning & behavior》1978,6(1):19-26
Ducklings (Anas Platyrhynchos domesticus) older than the so-called critical period (Days 1 and 2 posthatch) were exposed to an imprinting stimulus after various experimental histories. The first study found that in previously isolated 10-day-old subjects the stimulus exhibited the same capacity to reinforce an operant response and to generate a burst-like pattern of responding as in ducklings imprinted to it on Day 1. In Experiment 2, an imprinting stimulas exhibited reinforcing capacities in 5 to 10-day-old ducklings that had previously been imprinted to a different stimulus. Most of these ducklings came to prefer the second imprinting stimulus over the first. Experiment 3 revealed that in 5-day-old ducklings with a prior history of imprinting to a different stimulus, the otherwise neutral features of a new imprinting stimulus acquired the same kind of persistent control over distress vocalization that they acquire in younger, naive subjects. In all these studies, the only difference between imprinting in older vs. younger subjects was that in older subjects a novel imprinting stimulus initially evoked fear reactions rather than filial behavior. These findings contradict the traditional view of imprinting as an irreversible process that occurs only during a brief critical period, but are entirely consistent with a reinforcement model of imprinting. 相似文献
952.
953.
Talea Anderson Annie Gaines Chelsea Leachman Evan Peter Williamson 《The Reference Librarian》2017,58(4):257-277
As open education initiatives aiming to lower the cost of course materials appeared at two universities, librarians became involved in identifying open educational resources (OERs) for university courses. However, when considering a number of subject areas—particularly in colleges focused on upper-division instruction—librarians encountered problems related to the availability of resources and materials selection processes. For this project, librarians selected one prominent subject area at their respective institutions—engineering—and worked to identify best practices for introducing OERs into courses. They surveyed engineering faculty and instructors to better understand their perceptions and needs related to OERs and, based on this work, they suggest best practices for liaison librarians in specialized fields who wish to incorporate OERs into their outreach work with a focus on upper-division courses. 相似文献
954.
955.
An examination is reported of the effect of differences in reading strategies on the construction of meaning from novel length text. Following a brief review of psychological theory relevant to the question of how particular strategies could constrain meaning construction, specific differences are hypothesised in relation to Orwell's classic tale, Animal Farm. The results of an experimental examination using post‐graduate Diploma in Education students as subjects, and multidimensional scaling as the analytic technique, support the contention that reading strategies are important in the construction of differential meanings. The educational implications of the results are discussed in relation to the change in school practice from teacher‐directed reading to students reading more books but on their own or in small groups, without direct teacher intervention. 相似文献
956.
The medical ultrasonic phased array technology was modified for the non-destructive testing of marble sculptures and the feasibility of the approach was evaluated. For this purpose, 1?MHz, 64-channel phased array electronic and phased array transducers were developed. The specifications of the electronics and the transducers are presented and discussed. Ultrasound images of inner structures of a marble sculpture are presented. The problem of the acoustic matching layers for different states of deterioration is discussed and the developments in view of a suitable matching layer solution are presented. This matching layer is combined with a new coupling technique that protects the marble surface. The results of experiments on ultrasound phantoms and on a marble sculpture are presented. 相似文献
957.
Galileo changed the very concepts or categoriesby which natural philosophy could deal withmatter and motion. Central to these changeswas his introduction of time as a fundamentalconcept. He worked with the pendulum and withthe inclined plane to discover his new conceptof motion. Both of these showed him thatacceleration and time were important for makingmotion intelligible. 相似文献
958.
959.
960.