全文获取类型
收费全文 | 14256篇 |
免费 | 103篇 |
国内免费 | 5篇 |
专业分类
教育 | 10388篇 |
科学研究 | 1225篇 |
各国文化 | 80篇 |
体育 | 1114篇 |
综合类 | 7篇 |
文化理论 | 86篇 |
信息传播 | 1464篇 |
出版年
2023年 | 108篇 |
2021年 | 116篇 |
2020年 | 175篇 |
2019年 | 263篇 |
2018年 | 350篇 |
2017年 | 359篇 |
2016年 | 329篇 |
2015年 | 205篇 |
2014年 | 279篇 |
2013年 | 2580篇 |
2012年 | 297篇 |
2011年 | 361篇 |
2010年 | 223篇 |
2009年 | 216篇 |
2008年 | 322篇 |
2007年 | 231篇 |
2006年 | 301篇 |
2005年 | 198篇 |
2004年 | 183篇 |
2003年 | 174篇 |
2002年 | 213篇 |
2001年 | 319篇 |
2000年 | 287篇 |
1999年 | 260篇 |
1998年 | 128篇 |
1997年 | 156篇 |
1996年 | 171篇 |
1995年 | 175篇 |
1994年 | 139篇 |
1993年 | 161篇 |
1992年 | 234篇 |
1991年 | 209篇 |
1990年 | 207篇 |
1989年 | 242篇 |
1988年 | 244篇 |
1987年 | 205篇 |
1986年 | 204篇 |
1985年 | 216篇 |
1984年 | 189篇 |
1983年 | 229篇 |
1982年 | 170篇 |
1981年 | 159篇 |
1980年 | 156篇 |
1979年 | 229篇 |
1978年 | 181篇 |
1977年 | 164篇 |
1976年 | 149篇 |
1975年 | 128篇 |
1974年 | 119篇 |
1973年 | 125篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Infants as young as 12 months readily modulate their behavior toward novel, ambiguous objects based on emotional responses that others display. Such social-referencing skill offers powerful benefits to infants' knowledge acquisition, but the magnitude of these benefits depends on whether they appreciate the referential quality of others' emotional messages, and are skilled at using cues to reference (e.g., gaze direction, body posture) to guide their interpretation of such messages. Two studies demonstrated referential understanding in 12- and 18-month-olds' responses to another's emotional outburst. Infants relied on the presence versus absence of referential cues to determine whether an emotional message should be linked with a salient, novel object in the first study (N = 48), and they actively consulted referential cues to disambiguate the intended target of an affective display in the second study (N = 32). These findings provide the first experimental evidence of such sophisticated referential abilities in 12-month-olds, as well as the first evidence that infant social referencing at any age actually trades on referential understanding. 相似文献
102.
Research has shown that video games can be good for learning, particularly for STEM topics. However, in order for games to be scalable and sustainable, associated research must move beyond considerations of efficacy towards theories that account for classroom ecologies of students and teachers. This study asks how a digital game called Citizen Science, built using tropes and conventions from modern games, might help learners develop identities as citizen scientists within the domain of lake ecology. We conducted an expert-novice study, revealing that games literacy was a mediating variable for content understanding. In a follow-up classroom implementation, games literacy also operated as a variable, although students drove the activity, which mediated this concern. The teacher devised a number of novel pedagogies, such as a field trip, in response to the unit. We found evidence for the most powerful learning occurring through these activities that were reinforced via the curriculum. Students were most engaged by Citizen Science??s most ??gamelike?? features, and learners took up the core ideas of the game. Users also reported the experience was short of commercial gaming experiences, suggesting a tension between game cultures for learning and schools. 相似文献
103.
In human infancy, 2 criteria for intentional communication are (a) persistence in and (b) elaboration of communication when initial attempts to communicate fail. Twenty-nine chimpanzees (Pan troglodytes) were presented with both desirable (a banana) and undesirable food (commercial primate chow). Three conditions were administered: (a) the banana was delivered (successful communication), (b) half of the banana was delivered (partially successful communication), and (c) the chow was delivered (failed communication). The chimpanzees exhibited persistence in and elaboration of their communication in every condition except when the banana was delivered. Thus, their communication was about a specific item, demonstrating that both intentionality and nonverbal reference are capacities shared by humans with our nearest living relatives, the great apes. 相似文献
104.
D. Royce Sadler 《Instructional Science》1982,11(3):265-271
Many of the concepts and principles used in cybernetics are helpful in examining and designing instructional systems. However, the operational utility of cybernetic models is dependent on the match between the phenomenon being modelled and the model itself. In this paper, the position is taken that except in those forms of learning where the criteria for success are independent, fixed, and few in number, the cybernetic paradigm cannot be applied to curriculum development without a modified interpretation of how evaluation criteria can act as system control variables. 相似文献
105.
106.
107.
ABSTRACT: This study tracked and compared the performance of traditional classroom and on-line students in 2 introductory level food science classes. Student evaluations were also compared for the 2 groups. All of the Face-to-face (FTF) students were full-time college students. Seventynine percent of on-line students lived over 50 miles from campus. About 21% of the on-line enrollments were of skilled workers from the food industry. Performance on standardized exams was significantly higher for on-line students. Student evaluations were very positive for both forms of instruction. Differences in maturity, academic load, motivation, class standing, and experience/knowledge of the food industry may have all played a role in the observed results. Although our study cannot differentiate between these effects, it is apparent that on-line food science instruction can be an effective alternative for individuals who are unable to attend traditional courses. 相似文献
108.
J. H. Keffer M.D. 《Indian journal of clinical biochemistry : IJCB》1999,14(1):34-39
In this paper, I have attempted to place the evolving insights of the pathophysiology of coronary atherosclerosis in the context of the conventional perspective of clinical medicine. We strive to prevent death and to relieve suffering. Our clinical tools are critical but limited. Troponin, a biomarker of unprecedented organ specificity, in the context of the appropriate setting of new chest pain (or its equivalent syndrome), is an extraordinary aid to clinical diagnosis. Highly effective therapy is evolving which reduces loss of myocardium, undoubtedly reducing not only acute death but progression to congestive heart failure. Even if the newer therapies of the GpIIb/IIIa platelet antagonists and antithrombins are not yet widely employed, or may not be available to some physicians, the convincing demonstration of myocardial injury by troponin presents objective evidence to both the patient and the attending physician that serious compliance with a program of risk reduction must be urgently considered. Hoeg has described the mosaic of risk factors beyond the conventional and often ignored basic ones (JAMA, 1997, 277, 1387–1390). He provides thoughtful hope and encouragement for both patient and physician to do more in prevention of the subsequent predictable progression. We should look on a troponin positive vague unstable angina event as similar to a tremor which preceeds a subsequent earthquake. Although the mass of myocardium lost in such an episode may be small, it is a warning of the major acute myocardial infarction which can be predicted to follow at a later time if the course of the individual patient is not altered. Troponin is the objective evidence. 相似文献
109.
Preschool children's reasoning about ability 总被引:3,自引:0,他引:3
Young children's reasoning about ability was investigated among 155 preschoolers (M = 4 years, 10 months) across 3 studies. Results suggest that preschoolers are sensitive to mental state information when making judgments about another child's ability: They judged a child who finds a task easy to be smarter than one who finds the same task hard. Systematic patterns of errors on recall tasks suggest that preschoolers perceive positive correlations between (a) exerting effort and experiencing academic success, and (b) being nice and having high academic ability. Results from a comparison group of forty 9- to 10-year-olds (M = 9 years, 10 months) suggest that the preschool findings generally reflect emerging patterns of reasoning about ability that persist into later childhood, but that the perceived correlations between high effort and academic outcomes and between social and academic traits diminish with age. 相似文献
110.