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Mobile and wireless communication technologies not only enable anytime and anywhere learning, but also provide the opportunity to develop learning environments that combine real-world and digital-world resources. Nevertheless, researchers have indicated that, without effective tools for helping students organize their observations in the field, the mobile learning performance could be disappointing. To cope with this problem, this study proposes an interactive concept map-oriented approach for supporting mobile learning activities. An experiment has been conducted on an elementary school natural science course to evaluate the effectiveness of the proposed method. The experimental results show that the proposed approach not only enhances learning attitudes, but also improves the learning achievements of the students.  相似文献   
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应用超声波技术在温和条件下制几种硅胶固载化的咪唑类离子液体(1-丙基(三甲氧基硅基)-3-甲基咪唑类离子液体)材料。应用29Si NMR、元素分析、低温N2吸脱附实验和热重分析(TG)对所制备的样品进行了表征,并考察了其催化二氧化碳和环氧丙烷(PO)合成碳酸丙烯酯(PC)的性能。结果表明离子液体基团是以共价键固载到了二氧化硅上,固载化前后载体孔结构变化不大。几种材料在碳酸丙烯酯合成反应中都表现出良好的催化性能,PO转化率均大于96%,PC选择性都在98%以上,并表现出较好的重复使用性能。  相似文献   
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Sequential pattern mining is essential in many applications, including computational biology, consumer behavior analysis, web log analysis, etc. Although sequential patterns can tell us what items are frequently to be purchased together and in what order, they cannot provide information about the time span between items for decision support. Previous studies dealing with this problem either set time constraints to restrict the patterns discovered or define time-intervals between two successive items to provide time information. Accordingly, the first approach falls short in providing clear time-interval information while the second cannot discover time-interval information between two non-successive items in a sequential pattern. To provide more time-related knowledge, we define a new variant of time-interval sequential patterns, called multi-time-interval sequential patterns, which can reveal the time-intervals between all pairs of items in a pattern. Accordingly, we develop two efficient algorithms, called the MI-Apriori and MI-PrefixSpan algorithms, to solve this problem. The experimental results show that the MI-PrefixSpan algorithm is faster than the MI-Apriori algorithm, but the MI-Apriori algorithm has better scalability in long sequence data.  相似文献   
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Current civil engineering education should address the need to provide a broad vision, develop the higher-order skills of future civil engineers, enable them to adopt emerging technologies, and formulate innovative solutions to complex problems. This paper introduces relevant nanotechnology developments to convey the new vision and inspire creativity in civil engineering. It also presents a pedagogical framework for integrating nanotechnology education into a civil engineering curriculum and cultivating self-regulated learning and creativity skills for civil engineering students. The pedagogical framework includes the introduction of nanotechnology innovations and other relevant innovative technologies, and explicit instructions on cognitive strategies for facilitating and inspiring self-regulated learning and creativity. It is implemented with problem/project-based learning for a cocurricular project that requires self-regulated learning and creativity. This pedagogical framework provides a model for integrating emerging technology education and higher-order skill development into existing engineering curriculum. The outcomes from the implementation of the pedagogical framework are presented, and their further improvements are discussed.  相似文献   
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针对室内医疗系统信息化程度低、远程监控不足、药品投递研究偏少和当前系统设备无法满足实际需求等不足,提出了基于云技术与物联网药品投递智能系统框架;采用多核嵌入式系统、RFID、IEEE 802.11通信协议、开放云平台等构建了新型室内医疗系统与药品投送机器人系统;设计了远程移动端和PC端管理系统;构建相关试验环境,对系统与设备的相关性能进行测试,验证系统的合理性与可行性.实验结果表明:网络节点最快的控制周期为48 s/次,平均周期48.3 s/次,系统配送一颗药物平均花费时间4.19 s.系统上传云端数据最快上传储存时间为2.1 s,平均花费5.21 s,通信成功率大于90%.  相似文献   
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两足步行机器人并联腿机构的步态规划及仿真   总被引:1,自引:0,他引:1  
应用虚拟样机技术,建立了两足步行机器人并联腿机构的仿真模型,并在仿真环境下对步行机器人的行走姿态进行了规划和仿真试验,为确定步行机器人腿机构的结构参数和参数优化提供了实验平台,为研究和开发新型两足步行机器人及其控制奠定了理论基础。  相似文献   
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采用硫酸溶液浸渍TiO2干凝胶的方法制备了硫酸改性的TiO2粒子, 并组成了具有显著电流变性能的电流变材料. 用FT-IR、XRD、比表面积分析仪等表征了样品结构, 并测试了其电流变性能. 结果表明:由于硫酸根对晶粒生长的阻碍作用, 与纯TiO2粒子相比, 硫酸改性的TiO2粒子的晶粒尺寸降低, 比表面积提高, 并含有大量的强极性键SO. 当电场强度为3kV/mm时, 纯TiO2粒子电流变液的场致剪切应力与零场剪切应力之比(τE0)仅为80, 而硫酸改性TiO2电流变液的τE0高达500. 产生这些现象可归因于硫酸改性TiO2粒子带来的结构改变赋予其明显的界面极化能力.  相似文献   
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化学法催陈白酒的研究   总被引:8,自引:0,他引:8  
孙景庄  薛蕙茹 《食品科学》1994,15(12):39-41
化学法催陈白酒的研究孙景庄河南农业大学基础部450002薛蕙茹郑州轻工业学院新酒辛辣、暴冲、刺激性强、口感不佳。需经一定时间存贮,才能使杂味消失、香气增加、酒体醇和绵软。名优酒一般存贮l~3年。这种必不可少的存贮过程称自然老熟或陈酿[1]。老熟所用时...  相似文献   
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金银花是忍冬藤的花蕾,具有清热解毒和保健功能。金银花含绿原酸、芳樟醇,肌醇等有益人体的有机物。本文介绍了金银花晶、金银花露联合生产工艺,该工艺既降低了成本,又简化了工艺,还提高了产品的质量和经济效益。  相似文献   
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