全文获取类型
收费全文 | 4845篇 |
免费 | 33篇 |
国内免费 | 2篇 |
专业分类
教育 | 3406篇 |
科学研究 | 721篇 |
各国文化 | 34篇 |
体育 | 195篇 |
综合类 | 8篇 |
文化理论 | 86篇 |
信息传播 | 430篇 |
出版年
2023年 | 15篇 |
2022年 | 14篇 |
2021年 | 41篇 |
2020年 | 40篇 |
2019年 | 58篇 |
2018年 | 103篇 |
2017年 | 175篇 |
2016年 | 233篇 |
2015年 | 153篇 |
2014年 | 92篇 |
2013年 | 490篇 |
2012年 | 181篇 |
2011年 | 201篇 |
2010年 | 120篇 |
2009年 | 75篇 |
2008年 | 122篇 |
2007年 | 81篇 |
2006年 | 83篇 |
2005年 | 715篇 |
2004年 | 501篇 |
2003年 | 327篇 |
2002年 | 159篇 |
2001年 | 97篇 |
2000年 | 56篇 |
1999年 | 45篇 |
1998年 | 23篇 |
1997年 | 17篇 |
1996年 | 24篇 |
1995年 | 25篇 |
1994年 | 25篇 |
1993年 | 14篇 |
1992年 | 22篇 |
1991年 | 19篇 |
1990年 | 32篇 |
1989年 | 20篇 |
1988年 | 16篇 |
1987年 | 20篇 |
1986年 | 22篇 |
1985年 | 31篇 |
1984年 | 14篇 |
1983年 | 14篇 |
1981年 | 25篇 |
1980年 | 13篇 |
1979年 | 14篇 |
1977年 | 19篇 |
1976年 | 16篇 |
1975年 | 13篇 |
1974年 | 15篇 |
1972年 | 13篇 |
1968年 | 13篇 |
排序方式: 共有4880条查询结果,搜索用时 15 毫秒
991.
During Phase 1, 24 rats received CS1 (light)-shock trials while the remaining 24 rats received CS1 and shock on a random control schedule. During Phase 2, all subjects were presented trials of CS2 (tone)-shock. When CS2 was subsequently presented immediately after CS, while subjects licked for water, it was found that subjects that had received CS1-shock pairings during Phase 1 exhibited less suppression of licking to CS2, indicating less distress, than control subjects. The results are compatible with the opponent-process theory and suggest the presence of a positive hedonic afterreaction to an aversive event which reduced distress to a following aversive event. 相似文献
992.
As medical programs place increasing importance on competency-based training and surgical simulations for residents, anatomy laboratories, and body donation programs find themselves in a position of adapting to changing demands. To better assess the demand for “life-like” cadaveric specimens and evaluate the possible impacts that competency-based medical education could have upon the body donation program of McGill University, Canada, the authors tracked, over the course of the last 10 years, the number of soft-embalmed specimens, along with the number of teaching sessions and the residents enrolled in competency-based programs that are using cadaveric material. The results reveal that the number of soft-embalmed specimens used within residency training increased from 5 in 2009 to 35 in 2019, representing an increase from 6% of bodies to 36.5% of the total number of body donors embalmed in this institution. Correspondingly, the number of annual teaching sessions for residents increased from 19 in 2012 to 116 in 2019. These increases in teaching are correlated with increasing number of residents enrolled in competency-based programs over the last 3 years (Pearson r ranging from 0.9705 to 0.9903, and R2 ranging from 0.9418 to 0.9808). Those results suggest that the new skill-centered curricula which require residents to perform specific tasks within realistic settings, exhibit a growing demand for “life-like” cadaveric specimens. Institutions’ body donation programs must, therefore, adapt to those greater need for cadaveric specimens, which presents many challenges, ranging from the logistical to the ethical. 相似文献
993.
This paper problematises confidence as a frequently used explanation for performance in the mathematics classroom. I report on an interview-based study of how some English Advanced level (16+) students who have chosen to study mathematics, and their teachers, speak about confidence with respect to the learning of mathematics. I outline what constitutes confident learners for these teachers and, differently, for their students and what the students feel teachers could do to improve the students confident state. I discuss the implications of this for the education of prospective teachers of mathematics. 相似文献
994.
Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion. 相似文献
995.
Deaf children of Deaf parents perform better academically (Ritter-Brinton & Stewart, 1992), linguistically (Courtin, 2000; M. Harris, 2001; Vaccari & Marschark, 1997), and socially (Hadadian & Rose, 1991; M. Harris, 2001) than Deaf children of hearing parents. Twenty-nine Deaf children in residential schools were assessed to determine if a significant difference also exists in motor development between Deaf children with Deaf parents and Deaf children with hearing parents. In the locomotor area, 78.6% of Deaf children of Deaf parents and 73.3% of Deaf children of hearing parents reached or surpassed average performance levels. In regard to object control, 92.9% of Deaf children of Deaf parents and 93.3% of Deaf children of hearing parents reached or surpassed average performance levels. The study results show no significant difference between the motor development of Deaf children of Deaf parents and Deaf children of hearing parents. 相似文献
996.
997.
Pigeons were trained using a symbolic delayed matching-to-sample procedure involving bright versus dim houselight samples.
We hypothesized that when sample stimuli differ in salience, increasing the size of the retention interval will affect performance
on trials initiated by the more salient sample only. In agreement with this prediction, accuracy following the dim sample
did not decline as the retention interval increased, whereas accuracy following the bright sample declined to well below 50%
correct. In a second experiment, the less salient (dim) sample from Experiment 1 was arranged as the more salient sample in
a sample/no-sample procedure. Accuracy on dim sample trials then declined to well below 50% correct as the retention interval
increased, whereas accuracy on no-sample trials remained constant. The results suggest that when sample stimuli differ in
salience, pigeons may transform the nominal discrimination task into a detection task in which they respond on the basis of
the presence or absence of the more salient sample. 相似文献
998.
在近代诗坛上 ,黄遵宪的“新派诗”逐渐突破诗言志、比兴、温柔敦厚的传统诗教 ,在诗歌的主题内容、审美意蕴、表现方法、语言形式等方面出现了新的特点。这些新变虽然不够彻底 ,带有过渡性质 ,但已是解构旧诗的有效尝试。 相似文献
999.
In November 2005, the International Olympic Committee's Medical Commission issued a statement on Training the elite child athlete recommending that “more scientific research be done to better identify the parameters of training the elite child athlete”. This paper focuses on a specific issue related to training the child athlete: early specialization. While associations between early specialization and expertise development are highlighted, much research also suggests early specialization is associated with a range of negative consequences affecting physical, psychological, and social development. Alternately, some researchers have proposed that an early diversification approach does not disadvantage athletes in acquiring expertise, and is important for the development of intrinsic motivation and skill transferability. However, this review suggests that inadequate evidence exists to resolve the issue in favor of either approach. 相似文献
1000.
Assessing college students’ perceptions of a case teacher’s pedagogical content knowledge using a newly developed instrument 总被引:1,自引:0,他引:1
Ongoing professional development for college teachers has been much emphasized. However, previous research on learning environments
has seldom addressed college students’ perceptions of teachers’ PCK. This study aimed to evaluate college students’ perceptions
of a physics teacher’s PCK development using a newly developed instrument and workshop intervention. A mixed method design
was employed incorporating both quantitative and qualitative techniques. The survey “Assessing Students’ Perceptions of College
Teachers’ PCK” was adopted as the instrument of research. This survey was conducted twice in this study; with the pre-test
carried out during the mid-term exam and the post-test given in the last week of the semester. The results indicate that only
SMK and IRS showed significant difference in the four categories of the survey, while IOC and KSU did not. Furthermore, the
organized workshops helped the case teacher to better understand students’ prior conceptions of the subject matter and learning
difficulties, and further facilitated her adjustment of instructional strategies. The limitations of this study are discussed
and suggestions for improvement are also provided. 相似文献