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为解决校本课程评价体系缺失的共性问题,在实践教学研究的基础上,课题组以多元化评价、PTA量表评价、物理学科核心素养等理论为指导,构建了适用于初中物理校本课程新教学模式的学生学习评价体系. 相似文献
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文章从基于问题学习(PBL)的视角,以教师在中学物理教学中的实际经验为背景,分别阐述基于传统课堂和网络环境的教育评价途径,并结合广州市新版八年级物理教材与学生实际情况,对基于PBL教学模式的物理课堂实施教育评价的效果进行了分析与探讨。 相似文献
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新课程评价强调学生的参与和师生的互动,自评和他评相结合,实现评价主体的多元化.即被评价者从被动接受评价转化为主动参与评价,一改以往以管理者为主的单一评价主体的现象. 相似文献
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去耦覆盖层是降低水下结构声辐射的一个重要措施。为了给工程上去耦覆盖层降噪性能评价指标的选择提供理论参考,建立了点激励力作用下敷设去耦覆盖层的四端简支撑矩形板水下振动和声辐射理论模型,定义了可能表征去耦覆盖层降噪性能的五项评价指标。研究结果表明:只有振动传递损失相对独立于基板的长度、宽度和点激励力位置,而且能较好地描述去耦覆盖层隔离基板振动向水层传递的性能;而湿面均方振速插入损失较振动传递损失则能更好地反映辐射声功率插入损失,尤其在低频。作为评价指标,振动传递损失和湿面均方振速插入损失分别有各自的优点和缺点。 相似文献
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德育与物理学科教学互相依存、相互促进,德育评价与物理学科教学应同步展开.试图从课前诊断评价、课堂活动评价、课后作业评价3方面阐述将德育评价有效融合于物理教学评价的措施,以期在物理教学中贯彻落实"课程思政"的理念,为立德树人探索新的途径与经验. 相似文献
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文章基于对教学评价助学、助教优势价值的认识把握,以推动初中物理实验教学改革创新、培养提升学生物理核心素养为目标导向,探讨了在新课程背景下运用实验教学评价优化完善初中物理实验教学的路径方法。主要包含,构建科学评价目标、确定明确评价内容、实施多元评价手段三个方面。旨在通过将实验教学评价与初中物理实验教学深度融合的方式,进一步增大、增强初中物理实验教学效益,稳步推进学生全面发展、终身发展的实现。 相似文献
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In order to clarify and articulate the long-standing problems associated with the role of various compounds in grain refinement of as-cast steels, a comprehensive crystallographic study on grain refiners in a number of low carbon steels has been conducted using the edge-to-edge matching (E2EM) model, which has been successfully applied to explain and predict effective grain refiners in light metals. Five commonly investigated compounds, namely NbO, CeS, TiN, Ce2O3 and TiC, in steels were examined. According to the extent of crystallographic matching, the predicted grain refining potency of these five grain refiners is ranked in the order of NbO > CeS > TiN > Ce2O3 > TiC, which is consistent with previously reported experimental results. Four different orientation relationships between δ-ferrite and these grain refiners were predicted. One of them has been verified by previously published experimental data. The similarity and the advantages of the E2EM model over conventional Bramfitt’s model were also discussed. 相似文献
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In the present study, an integrated layer of iron aluminides of FeAl and Fe3Al was formed on the surface of a low carbon steel sheet by a two-step process. The first step was hot dipping of the steel in a molten aluminum pool and secondly laser surface processing using a pulsed Nd:YAG laser. The corrosion resistance of the coated specimens was evaluated by activation polarization and Tafel methods. The results show that laser processing of the aluminized steel leads to a considerable increase in its corrosion resistance compared to both uncoated and merely aluminized materials. 相似文献
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B.A. Butler E.E. van Dyk F.J. Vorster W. Okullo M.K. Munji P. Booysen 《Physica B: Condensed Matter》2012,407(10):1501-1504
Low concentration photovoltaic (LCPV) systems have the potential to reduce the cost per kWh of electricity compared to conventional flat-plate photovoltaics (PV) by up to 50%. The cost-savings are realised by replacing expensive PV cells with relatively cheaper optical components to concentrate incident solar irradiance onto a receiver and by tracking the sun along either 1 axis or 2 axes. A LCPV module consists of three interrelated subsystems, viz., the optical, electrical and the thermal subsystems, which must be considered for optimal module design and performance. Successful integration of these subsystems requires the balancing of cost, performance and reliability. In this study LCPV experimental prototype modules were designed, built and evaluated with respect to optimisation of the three subsystems and overall performance. This paper reports on the optical and electrical evaluation of a prototype LCPV module. 相似文献
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系统地计算了各种手性碳纳米管最低导带的电子速度和有效质量的变化规律,在此基础上推断手性碳纳米管低偏压下的输运特征,计算表明:在低偏压电子输运时,同一系列(手性角相同)的各种手性金属碳纳米管的输运性质相同,与管径无关,但不同系列的手性金属碳纳米管的输运性质有明显区别;而同一系列的各种手性半导体型碳纳米管的输运性质有一定差异,但不同系列的手性半导体型碳纳米管的输运性质有着显著差异.这一结果说明:碳纳米管在低偏压下的输运特征与系列有着密切的关系,手性角是决定各种碳纳米管在低偏压下具有不同输运性质的最关键的几何参
关键词:
碳纳米管
手性角
电子速度
有效质量 相似文献
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J.P. Popi?B.V. Jegdi? J.B. Bajat?. Veljovi? S.I. Stevanovi?V.B. Miškovi?-Stankovi? 《Applied Surface Science》2011,257(24):10855-10862
The influence of deposition temperature and concentration of NaNO2 in the phosphating bath on the surface morphology and coverage of iron-phosphate coatings on low carbon steel was investigated. The phosphate coatings were chemically deposited on steel from phosphate bath at different temperatures (30-70 °C) and with the addition of different amounts of accelerator, NaNO2 (0.1, 0.5 and 1.0 g dm−3). The morphology of phosphate coatings was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The composition of iron-phosphate coatings was determined using energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Surface coverage was evaluated by the voltammetric anodic dissolution (VAD) technique.It was shown that the increase in temperature of the NaNO2-free phosphating bath up to 70 °C caused an increase in surface coverage. The addition of NaNO2 in the phosphating bath significantly increased the surface coverage of phosphate coatings deposited at temperatures lower than 50 °C. The phosphate crystals were of laminated and needle-like structures for deposits obtained at temperatures lower than 50 °C, while at higher temperatures needle-like structure was transformed to laminated structure. The increase in NaNO2 concentration in the phosphating bath from 0.1 to 1.0 g dm−3 did not significantly increase the surface coverage, but decreased the crystals size, consequently favouring the phosphate nucleation and better packing of the crystals. 相似文献
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Super-aligned carbon nanotube (SACNT) arrays are grown on the surface of micro perforated panel (MPP) in the hope of improving the acoustic performance of MPP absorbers by virtue of their unique properties. Scanning electron microscopy reveals that SACNT arrays did not block the perforations of MPPs or changed the perforation diameter due to their “super-aligned” nature, although MPPs are thickened. The absorption effect of SACNT arrays which are of the same and different lengths with different incident side on MPP absorbers are investigated, and standing wave tube method is used to determine the normal sound absorption coefficient. Results show that both of the lengths of SACNT arrays and the incident side have effects on the sound absorption performance of MPP absorbers. And generally SACNT arrays help to improve the sound absorption capacity of MPP absorbers in low-frequency regions only when the SACNT arrays surface is the incident side. SACNT arrays decrease absorption performance of MPP absorbers when the MPP surface is used as the incident side. Moreover, SACNT arrays are found to increase the acoustic ability of MPP absorbers with the same structure parameters monotonically at lengths up to 600 μm in the condition that the SACNT arrays surface is used as the incident side. 相似文献
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We investigate the effects of low cut-off frequency of optical receiver on the performance of lightwave systems. The results show that we can reduce the tone-induced power penalty by ∼0.8 dB (tone frequency = 1 MHz) using a high-pass filter in the optical receiver. In addition, our calculation shows that the power penalty can be negligible (<0.1 dB) even when the low cut-off frequency of the 10 Gb/s optical receiver is increased up to ∼10 MHz. 相似文献
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