全文获取类型
收费全文 | 33877篇 |
免费 | 348篇 |
国内免费 | 30篇 |
专业分类
教育 | 24886篇 |
科学研究 | 3198篇 |
各国文化 | 203篇 |
体育 | 2042篇 |
综合类 | 34篇 |
文化理论 | 571篇 |
信息传播 | 3321篇 |
出版年
2022年 | 134篇 |
2021年 | 232篇 |
2020年 | 363篇 |
2019年 | 498篇 |
2018年 | 2791篇 |
2017年 | 2784篇 |
2016年 | 2242篇 |
2015年 | 547篇 |
2014年 | 685篇 |
2013年 | 4296篇 |
2012年 | 783篇 |
2011年 | 1364篇 |
2010年 | 1326篇 |
2009年 | 883篇 |
2008年 | 1161篇 |
2007年 | 1643篇 |
2006年 | 506篇 |
2005年 | 762篇 |
2004年 | 818篇 |
2003年 | 689篇 |
2002年 | 509篇 |
2001年 | 428篇 |
2000年 | 417篇 |
1999年 | 402篇 |
1998年 | 210篇 |
1997年 | 248篇 |
1996年 | 254篇 |
1995年 | 213篇 |
1994年 | 210篇 |
1993年 | 193篇 |
1992年 | 302篇 |
1991年 | 305篇 |
1990年 | 329篇 |
1989年 | 311篇 |
1988年 | 295篇 |
1987年 | 248篇 |
1986年 | 256篇 |
1985年 | 322篇 |
1984年 | 266篇 |
1983年 | 255篇 |
1982年 | 196篇 |
1981年 | 206篇 |
1980年 | 176篇 |
1979年 | 240篇 |
1978年 | 214篇 |
1977年 | 194篇 |
1976年 | 161篇 |
1975年 | 128篇 |
1974年 | 120篇 |
1973年 | 147篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The purpose of this study was to describe and understand the range of outcomes of class visits to natural history museums.
The theoretical framework is based on the multifaceted process of learning in free choice learning environments, and emphasizes
the unique and individual learning experience in museum settings. The study’s significance is in highlighting several possible
cognitive as well as non-cognitive learning effects in museums class visits, by providing the student’s point of view. Data
was collected by semi-structured interviews with 50 students in grades 6–8 on the day following the visit. We present evidence
that students expressed several learning outcomes, connected directly and indirectly to the scientific content of the visit.
Content oriented outcomes included acquiring scientific knowledge and making connections to prior knowledge; social oriented
outcomes were identified in students’ statements regarding communicating knowledge and social aspects of learning; and interest
oriented outcomes were evidenced by students’ expressions about emotions, interest and curiosity. The aggregate data addressed
the common outcomes and the impact of class visits to natural history museums in the short term. Comparisons between two types
of museums show significant differences in several aspects, regarding the exhibit and/or the activity type. Practical ideas
for structuring the ultimate experience are included. 相似文献
992.
J. Roschelle D. Tatar N. Shechtman J. Knudsen 《Educational Studies in Mathematics》2008,68(2):149-170
One of the great strengths of Jim Kaput’s research program was his relentless drive towards scaling up his innovative approach to teaching the mathematics of change and variation. The SimCalc mission, “democratizing access to the mathematics of change,” was enacted by deliberate efforts to reach an increasing number of teachers and students each year. Further, Kaput asked: What can we learn from research at the next level of scale (e.g., beyond a few classrooms at a time) that we cannot learn from other sources? In this article, we develop an argument that scaling up research can contribute important new knowledge by focusing researchers’ attention on the robustness of an innovation when used by varied students, teachers, classrooms, schools, and regions. The concept of robustness requires additional discipline both in the design process and in the conduct of valid research. By examining a progression of three studies in the Scaling Up SimCalc program, we articulate how scaling up research can contribute to designing for and evaluating robustness. 相似文献
993.
A. Mark Langan David M. Shuker W. Rod Cullen David Penney Richard F. Preziosi C. Philip Wheater 《Assessment & Evaluation in Higher Education》2008,33(2):179-190
There are many influences on how assessors grade themselves and others. Oral presentations are useful for exploring such factors in peer, self‐ and tutor marked assessments, being rapidly completed and assessed, commonly used in HE and very difficult to anonymize. This opportunistic study examined the effects of gender and level of attainment on the triangulation of marks awarded to student presenters. Grades generated by peer assessment were associated more strongly with tutor‐awarded marks than those from self‐assessment. For self‐assessment there was a strong effect of gender (female students undervalued their performance compared with tutor grades). Peer assessment produced higher marks than from tutors, perhaps because of the close‐knit community developed during residential courses. For tutor marks, the greatest variability was at the lower end of the scale, whereas peer assessors were most variable when marking students who self‐evaluated or peer assessed highly. Students awarded a narrower range of marks to peers compared with tutors, but when self‐assessing used a larger range. Presentations by students who admitted to little sleep the night before received lower grades from both peers and tutors, but this was not reflected by self‐assessments, suggesting they were unaware of their poorer performances. Sessions with fewer talks (four rather than seven) reduced the ‘dip’ in marks previously observed in the middle of sessions. Findings are discussed in the context of bias in this mode of assessment. 相似文献
994.
PhD students’ work conditions and study environment in university- and industry-based PhD programmes
During the last 10 years, new models of funding and training PhD students have been established in Denmark in order to integrate industry into the entire PhD education. Several programmes have been conducted where it is possible to co-finance PhD scholarships or to become an employee as an industrial PhD in a company. An important question is what impact these new conditions will have on the PhD students’ training, work conditions and study environment. In this article, the new type of programmes will be presented together with data analysis of PhD students’ work conditions and study environment in various programmes mainly based on a research project from 2006. The results of this study show no significant difference between PhD students in a traditional university PhD programme and PhD students in an industrial programme concerning working environment. However, the study shows significant differences in the intercultural dimension, where foreign PhD students are significantly more satisfied with their study environment compared with Danish PhD students. In general the workload is very high and the environment is stressful for all PhD students. 相似文献
995.
This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications. 相似文献
996.
This study applies Kalleberg’s framework to better understand the effects of diverse demographic faculty characteristics on
dimensions of job satisfaction. We also extend his work and the work of others to explore the contextual effects of academic
disciplines on faculty job satisfaction. We find that women are consistently less satisfied than their male colleagues and
that the effect of being female varies by discipline on levels of job satisfaction. We also find race/ethnicity has mixed
effects on dimensions of job satisfaction but the effects of race/ethnicity tend to be constant across discipline. Our findings
hold important implications for those seeking to understand the experiences of college faculty from diverse demographic backgrounds. 相似文献
997.
This study examined the effects of students' characteristics (gender, age, and first-language spoken at home) on their perceptions about problem-based learning (PBL). The study revealed that students from the fifth, sixth and seventh grades perceived PBL in a positive way but there were significant differences between the grades. The resources identified by students as the most useful to their self-directed learning in the PBL unit varied between these grades. However, other parameters such as gender and first-language spoken at home did not have effects on students' perceptions. 相似文献
998.
Fei-Ching Chen Thomas C. Wang 《Educational technology research and development : ETR & D》2009,57(5):587-612
This paper studies the social talk of high school students in online discussion forums. On-task talk has generally been assessed as valuable discussion because it contributes directly to productive learning. Off-task conversation, on the other hand, is often regarded as useless and a waste of time. Should this social talk indeed be regarded as an off-task activity? Is social talk such as greeting, excusing, comforting and sharing personal feelings irrelevant to learning? This study analyzes threads and argues that social talk is interwoven with on-task talk. It is interesting to note that a substantial quantity of off-task messages served the latent function of guiding group discussion toward making progress in solving collaborative problems in a subtle and indirect manner. The power of “soft talk” embedded in off-task social conversation is explored and fully discussed. 相似文献
999.
Kirby Deater-Deckard Paula Y. Mullineaux Stephen A. Petrill Lee A. Thompson 《Reading and writing》2009,22(1):107-116
We examined the associations between components of temperament and children’s word and pseudo-word reading skills, in a school-age
sample using a within-family internal-replication design. We estimated the statistical prediction of word and pseudo-word
reading in separate regression equations that included the main effects of, and two-way interaction between, Surgency and
Effortful Control. Children with better Effortful Control scores showed better reading skills. Surgency was unrelated to reading
skills, but moderated the effect of Effortful Control. The positive association between reading skills and Effortful Control
was present only for children who were low in Surgency. Thus, reading achievement in school-age children is optimized by strong
Effortful Control, but these processes may be disrupted for those children who are high in Surgency. 相似文献
1000.
Ali Bikmoradi Mats Brommels Alireza Shoghli Davoud Khorasani Zavareh Italo Masiello 《Higher Education》2009,57(4):417-427
In Iran, restructuring of medical education and the health care delivery system in 1985 resulted in a rapid shift from elite
to mass education, ultimately leading to an increase in the number of medical schools, faculties, and programs and as well
as some complications. This study aimed to investigate views on academic culture, values, and routines held by faculty members.
A nation-wide survey conducted in six public medical schools in Iran. The research findings show weak organizational culture
and values, together with routine behaviors sensed as a negative and low satisfaction with academic leadership. The research
evidence suggests bureaucracy, politicization, conservativeness, and centralization as common features of medical schools
in Iran and also suggests suitable supervisory skills to tackle the tension between governmental management and academic leadership
with cultural changes, the creation of new values, and adoption more efficient routines. 相似文献