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本文对不同梯度区高度的VGF法温场生长碲锌镉(CdZnTe)晶体过程进行了稳态和非稳态仿真模拟分析。研究发现,晶体生长等径初期界面凸度随着梯度区高度的增加而减小;等径末期界面凸度受梯度区高度的影响不大;界面的凸度与固液界面温度梯度变化率正相关。非稳态模拟结果显示,现有变温条件下,晶体生长过程中固液界面凸度存在先增大后减小的趋势,趋势转变点接近梯度区高度中点;界面形状的变化趋势受固液界面上生长速度分布直接影响;对比而言,10 cm高的梯度区更容易实现前中期固液界面凸界面的获得,利于形成高单晶率CdZnTe晶体。 相似文献
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自主创新学习模式是以“学生为主、教师为辅”的学习模式.本文根据自主创新学习的优点以及对网络教学的分析,利用计算机网络和各种媒体构建自主创新学习,结合技工院校课程教学实践,积极探索自主创新学习在FLASH课程教学中的运用. 相似文献
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Despite the rapid advances in mobile tech-nology, many constraints still prevent mobile de-vices from running resource-demanding applica-tions in mobile environments. Cloud computing with flexibility, stability and scalability enables ac-cess to unlimited resources for mobile devices, so more studies have focused on cloud computing- based mobile services. Due to the stability of wire-less networks, changes of Quality of Service (QoS) level and user' real-time preferences, it is becoming challenging to determine how to adaptively choose the “appropriate”service in mobile cloud compu-ting environments. In this paper, we present an a-daptive service selection method. This method first extracts user preferences from a service's evaluation and calculates the similarity of the service with the weighted Euclidean distance. Then, they are com-bined with user context data and the most suitable service is recommended to the user. In addition, we apply the fuzzy cognitive maps-based model to the adaptive policy, which improves the efficiency and performance of the algorithm. Finally, the experi-ment and simulation demonstrate that our approach is effective. 相似文献
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