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Yamuna Krishnan 《Resonance》2008,13(2):195-197
DNA is fast taking on a new aspect utilizing it’s physical property of persistence length and chemical property of base pairing
to build architectures in 1D, 2D and 3D. This field is called structural DNA nano-technology and is poised to revolutionize
several areas ranging from materials science to cell biology. 相似文献
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Asmalina Saleh Chen Yuxin Cindy E. Hmelo-Silver Krista D. Glazewski Bradford W. Mott James C. Lester 《科学教学研究杂志》2020,57(9):1490-1518
Collaborative inquiry learning affords educators a context within which to support understanding of scientific practices, disciplinary core ideas, and crosscutting concepts. One approach to supporting collaborative science inquiry is through problem-based learning (PBL). However, there are two key challenges in scaffolding collaborative inquiry learning in technology rich environments. First, it is unclear how we might understand the impact of scaffolds that address multiple functions (e.g., to support inquiry and argumentation). Second, scaffolds take different forms, further complicating how to coordinate the forms and functions of scaffolds to support effective collaborative inquiry. To address these issues, we identify two functions that needed to be scaffolded, the PBL inquiry cycle and accountable talk. We then designed predefined hard scaffolds and just-in-time soft scaffolds that target the regulation of collaborative inquiry processes and accountable talk. Drawing on a mixed method approach, we examine how middle school students from a rural school engaged with Crystal Island: EcoJourneys for two weeks (N=45). Findings indicate that hard scaffolds targeting the PBL inquiry process and soft scaffolds that targeted accountable talk fostered engagement in these processes. Although the one-to-one mapping between form and function generated positive results, additional soft scaffolds were also needed for effective engagement in collaborative inquiry and that these soft scaffolds were often contingent on hard scaffolds. Our findings have implications for how we might design the form of scaffolds across multiple functions in game-based learning environments. 相似文献
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This paper introduces a technical method by which bone tissue bionic scaffolds are fabricated on a selective laser sintering machine. It also analyses determinative factors in fabricating porous structure using this method, and proposes a new technique to fabricate porous structure by rapid prototyping method. 相似文献
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Learning to become a teacher is a developmental process, part of which is learning to become a reflective practitioner. The authors have implemented a structured approach to developing the habits of critical reflection, the purpose of which is to guide their university students (who are pre-service teachers) to progress through the stages of teacher development and to facilitate self-motivated professional growth. Their attempts to incorporate into these pre-service teachers' learning the ‘practice’ part of reflective practice have included the development of different kinds of practical and applied tasks. In turn, their attempts to incorporate the ‘reflective’ part of reflective practice have involved the embedding in assessment activities of different scaffolds for metacognitive reflection. Their innovative processes of embedding reflection in assessment have been guided by Dewey's and Schön's views of reflection, their own views of the teacher education process, and Brookfield's conception of ‘critical lenses’ which can be used as a scaffold to structure professional growth and development. 相似文献
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Koen Veermans Ton de Jong Wouter R. van Joolingen 《Interactive Learning Environments》2013,21(3):229-255
Providing learners with computer-generated feedback on their learning process in simulation-based discovery environments cannot be based on a detailed model of the learning process due to the “open” character of discovery learning. This paper describes a method for generating adaptive feedback for discovery learning based on an “opportunistic” learning model that takes the current hypothesis of the learner and the experiments performed to test this hypothesis as input. The method was applied in a simulation–based learning environment in the physics domain of collisions. Additionally, the method was compared to an environment in which subjects received predefined feedback on their hypotheses, not taking the experimentation behavior into account. Results showed that overall both groups did not differ on knowledge acquired. A further analysis indicated that, in their learning processes, the learners in the experimental condition built upon their intuitive knowledge base, whereas the learners in the control condition built upon their conceptual knowledge base. In addition, measures of the learning process showed that the subjects in the experimental condition adopted a more inquiry-based learning strategy compared to the subjects in the control condition. We concluded, therefore, that providing learners with adaptive feedback had a different and beneficial effect on the learning process compared to more traditional predefined feedback. 相似文献
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Martina S. J. van Uum Roald P. Verhoeff Marieke Peeters 《International Journal of Science Education》2013,35(18):2461-2481
ABSTRACTThis paper describes a multiple case study on open inquiry-based learning in primary schools. During open inquiry, teachers often experience difficulties in balancing support and transferring responsibility to pupils’ own learning. To facilitate teachers in guiding open inquiry, we developed hard and soft scaffolds. The hard scaffolds consisted of documents with explanations and/or exercises regarding difficult parts of the inquiry process. The soft scaffolds included explicit references to and additional explanations of the hard scaffolds. We investigated how teacher implementation of these scaffolds contributed to pupils’ self-directed learning during open inquiry. Four classes of pupils, aged 10–11, were observed while they conducted an inquiry lesson module of about 10 lessons in their classrooms. Data were acquired via classroom observations, audio recordings, and interviews with teachers and pupils. The results show that after the introduction of the hard scaffolds by the teacher, pupils were able and willing to apply them to their investigations. Combining hard scaffolds with additional soft scaffolding promoted pupils’ scientific understanding and contributed to a shared guidance of the inquiry process by the teacher and her pupils. Our results imply that the effective use of scaffolds is an important element to be included in teacher professionalisation. 相似文献
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Cognitive skills acquisition involves developing the ability to solve problems in knowledge-rich task domains, and is particularly important for any individual attempting to meet the challenges of our modern, knowledge-driven economy. This type of economy argues for reconceptualizing cognitive skills acquisition as a lifelong process. Research has shown that worked-out examples are the key to initial cognitive skill acquisition and, therefore, critical to lifelong learning. The extent to which learners' profit from the study of examples, however, depends on how well they explain the solutions of the examples to themselves. This paper discusses our own research on different types of computer-based learning environments that indirectly foster self-explanations by (a) fostering anticipative reasoning, (b) supporting self-explanations during the transition from example study to problem solving, and (c) supporting self-explanation activities with instructional explanations. It also discusses ways of leveraging new computer and video technologies to enhance these environments by representing problem situations and their concepts dynamically. The paper concludes by suggesting that these learning environments, if employed successfully, can encourage systematic, lifelong learning. 相似文献
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杨春蓉 《福建工程学院学报》2018,(3):215-218
以透明质酸、胶原和生物玻璃为原料制备复合支架材料,并对其矿化性能进行研究。实验将透明质酸、胶原和生物玻璃按比例混合,再进行交联处理,冷冻干燥得到支架材料,最后将其浸入模拟体液进行矿化,分析生物分子在矿化过程中的作用机制。研究发现,该复合支架材料具有三维多孔的微观结构; 在模拟体液中的矿化产物为羟基磷灰石。胶原蛋白和透明质酸对溶液中钙、磷离子的亲和力构成了矿化机制的基础。且两种生物分子可相互键合,促进钙化。该支架具有良好的矿化性能,可用于骨缺损的修复。 相似文献