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1.
The links uncovered by research connecting teacher beliefs to classroom practice and student inquiry-based learning are tenuous. This study aims at examining (a) how teacher beliefs influenced practices; and (b) how the influence on practices, in turn, impacted student inquiry learning in a CSCL environment. Through a fine-grained comparative analysis of two cases, this study explores how two teachers with different collections of beliefs enacted the same mathematics lesson on division and fractions in a CSCL environment premised on inquiry principles, and what the connections between different enactments and students’ progressive inquiry process and outcomes were. The findings suggest that the two teachers’ adherence to different beliefs led to different practices, which in turn contributed to different student learning processes and outcomes. We interpret these differences that shaped the students’ opportunities for progressive inquiry in the CSCL environment. We conclude that the teacher holding “innovation-oriented” beliefs tended to enact the lesson in patterns of inquiry-principle-based practices and technology-enhanced orchestration; these patterns interacted with each other to contribute to student inquiry learning and effective use of technology affordances.  相似文献   
2.
In situ imaging techniques in conjunction with electrochemical measurements were used to study the behavior of steel surfaces in simple chloride solutions. The imaging method detected the presence of significantly thicker uniform layers than the original passive oxide. The layers were found to form in chloride after the steel was anodically polarized following reduction of the passive oxide film. The growth of the layer depended on the degree of prior passive oxide reduction. Formation of the layer was also sensitive to underlying structure and enabled rapid location of regions of higher corrosion rate across laser welds in steels.  相似文献   
3.
With the realization that more research is needed to explore external factors (e.g., pedagogy, parental involvement in the context of K-12 learning) and internal factors (e.g., prior knowledge, motivation) underlying student-centered mobile learning, the present study conceptually and empirically explores how the theories and methodologies of self-regulated learning (SRL) can help us analyze and understand the processes of mobile learning. The empirical data collected from two elementary science classes in Singapore indicates that the analytical SRL model of mobile learning proposed in this study can illuminate the relationships between three aspects of mobile learning: students’ self-reports of psychological processes, patterns of online learning behavior in the mobile learning environment (MLE), and learning achievement. Statistical analyses produce three main findings. First, student motivation in this case can account for whether and to what degree the students can actively engage in mobile learning activities metacognitively, motivationally, and behaviorally. Second, the effect of students’ self-reported motivation on their learning achievement is mediated by their behavioral engagement in a pre-designed activity in the MLE. Third, students’ perception of parental autonomy support is not only associated with their motivation in school learning, but also associated with their actual behaviors in self-regulating their learning.  相似文献   
4.
This exploratory study analyzes how students use different communication modes to share information, negotiate meaning and construct knowledge in the process of doing a group learning activity in a Primary Grade 5 blended learning environment in Singapore. Small groups of students interacted face-to-face over a computer-mediated communication (CMC) technology called Group Scribbles (GS) to jointly complete a learning task. The lesson designers attempted to optimize the use of CMC technology and face-to-face (F2F) discussion in students’ collaborative learning, with the aim of harnessing the specific features of each medium. Building on notions from communication studies and from interaction analysis, we observed the construction and evolution of the interactions through analyzing the artifacts that were produced by a group of students – in verbal talk, gestures, and sketches drawn and text inscribed in GS. F2F and GS interactions intertwined to support collaborative learning. The findings from this study could inform design aspects concerning integrating and reinforcing the strengths of both communication modes when introducing computer-assisted collaborative learning (CSCL) in a F2F classroom.  相似文献   
5.
Enhancing learning ecology on the Internet   总被引:6,自引:0,他引:6  
Abstract Recent notions view learning as participation in a learning environment or community where learners work together and support each other as they use information resources and tools to pursue their learning goals and solve problems. A broader meaning is to extend the idea of the learning environment to the overall setting in which learning communities come into existence, evolve, fade away, regenerate or transform. The advent of the Internet has brought about a powerful medium for creating and supporting such a notion of the learning ecology. Through the image of biological ecologies with their diversity, complex dynamics, and opportunistic niches for growth, learning problems and solutions on the Internet are explored and ways to enhance the ecology are suggested.  相似文献   
6.
A cone-shaped MS inlet and on-line electrochemistry (EC) were used to enhance the ionization efficiency in electrospray ionization mass spectrometry (ESI MS) of purine bases. A pathway of positive ion mode ESI may involve oxidation of purine bases, guanine, adenine, xanthine and hypoxanthine, by 1e, 1H+ processes. The electrospray process generates dimers of purine bases that are detected in ESI MS as protonated ions, except for xanthine, for which a protonated radical dimer is detected. Thus electrochemical oxidation of purine bases during ESI may generate reactive radicals that can subsequently dimerize. Dimer formation is facilitated in ESI MS when the carrier solution pH is high. The positive ion mode ESI MS ionization is consistent with the reactivity of the bases toward oxidation. Furthermore, the formation of the protonated ions, and Na+ and K+ adducts of the bases, expected in positive ion ESI MS, are observed. In addition, unusual H-bonding of purine bases guanine and xanthine is confirmed by ESI MS. Application of low EC voltage to the on-line EC cell in EC/ESI MS improves the sensitivity and correlates with the decrease of the intensity of the dimers, possibly as a result of their further oxidation.  相似文献   
7.
This paper reports a case study in a Singapore school where a group of 'at risk' secondary students were given a series of linked computer-based business and consumer projects involving word processing, survey design and analysis, and presentation of results with computer graphics. There were clear benefits in terms of the group's motivation, behaviour and performance on tests, particularly in English. Both quantitative and qualitative data to support the findings are provided. The theoretical underpinnings of constructivism, collaborative inquiry and situated learning provide the conceptual framework for this case study.  相似文献   
8.
Architects based the Intel 870 system architecture on the scalability port, a coherent system interconnect. The system's building-block approach lets a single chip set support a wide range of server segments.  相似文献   
9.
The plant pathogenic fungus Verticillium dahliae produced extracellular alkaline protease activity when grown in liquid medium supplemented with a protein source. A serine protease was purified 80-fold in a single step, using cation-exchange chromatography, from the filtrate of cultures grown with skim milk as a protein source. N-terminal amino acid sequence analysis of the 30-kDa protein (VDP30) that copurified with the serine protease activity suggested that VDP30 is a trypsin-like protein. The purified enzyme hydrolyzed the synthetic substrate N alpha-benzoyl-DL-arginine p-nitroanilide hydrochloride (BAPNA), and the activity on BAPNA was inhibited by leupeptin, further verifying the trypsin-like nature of the enzyme.  相似文献   
10.
Nonseismically detailed reinforced concrete (RC) shear walls adjacent to transfer structure in tall buildings are found to have short shear spans and designed to hold considerable axial load. In a previous paper, a Modified Mohr's Axial Capacity Model was developed by the authors to estimate the axial collapse of these RC walls in seismic events, which is expressed as an axial load ratio devised based on classical Mohr's circle framework. It was noted that the previous model can be complicated and appears not suitable for direct adoption in engineering design check. Hence, in this paper, a new simplified seismic axial collapse capacity prediction model is formulated to improvise the previous model. This simplified model typifies the practical range of shear wall geometry, concrete strength, steel reinforcement stress and strain and reinforcement ratio. Simplified charts to estimate maximum shear stress are presented for quicker design check. The complex inelastic buckling stress calculation is simplified into graphs and design equations. A knife‐edge feasible solutions zone is defined, expressed as an inequality function of axial‐to‐shear capacity ratio and additional axial stress induced by lateral shear. Recommendations are made based on results obtained from Genetic Algorithm search and further justified by parametric studies.  相似文献   
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