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关键词： 初中物理   试卷讲评课   教学设计  

摘要： 基于目前初中物理试卷讲评课的现状分析,遵循试卷讲评课的时效性、针对性和主导性原则,从课前根据测验结果分析设计教学环节、课中的分步设计优化与应变、课后教学反馈的试题改进三个方面完善试卷讲评课的教学设计,发挥试卷讲评课的激励、协作、提升作用。

关键词： 高超声速飞行器   姿态控制   扩张状态观测器   神经网络   鲁棒控制  

摘要： 针对高超声速飞行器快时变、强耦合、非线性的特点,为提高其抗干扰性能和姿态角快速跟踪性能,提出了一种基于扩张状态观测器的三通道姿态角鲁棒控制方法。首先,根据高超声速飞行器动力学模型,给出面向姿态角的控制模型;其次,利用扩张状态观测器对总扰动包括通道间耦合作用、参数不确定性及外部扰动进行估计补偿,并结合神经网络最小参数学习法设计姿态控制律,采用Lyapunov理论完成闭环稳定性分析;最后,仿真结果表明所提控制策略具有更好的控制性能和抗扰能力。

关键词： 智能机器人  

ISBN: (纸本)9787122437037

摘要： 本书分为三篇内容。第1篇是多智能体机器人系统的基础 (第1-3章)，介绍多智能体系统的概念、必要的控制原理和数理知识。第2篇是多智能体机器人系统的控制 (第4-5章)，分别针对一阶和二阶多智能体系统进行了各种情况下的一致性和编队控制与验证。第3篇是多智能体机器人系统的应用 (第6-8章)，分别针对多无人车系统、多无人机系统以及由它们组成的异构多智能体系统，讲述了在各种情况下的一致性控制、编队控制和最优控制等的实验与应用。

关键词： dispersion behavior   water model   silicone oil   viscosity  

摘要： Molten oxides are widely used as refining slag and mold flux in the steelmaking process. In the stationary state, the molten oxide and the molten iron form a layer due to their density difference. However, in the actual operation, they are partially mixed and dispersed as droplets, which can increase the slag-metal reaction area or cause the formation of nonmetallic inclusions. In this study, the dispersion behavior in density stratified flow was investigated by water model experiments. It was suggested that the dispersion behavior of silicone oil was affected by viscosity. As the kinematic viscosity was higher than 100 mm(2)/s, droplet generation tended to be less likely to occur. The conventional equations for interface instability and energy balance underestimated the critical velocity of droplet generation when the kinematic viscosity of oil was higher than 100 mm(2)/s. On the other hand, we were able to reproduce the influence of viscosity in this experiment by applying the empirical formula using the Ohnesorge number. Furthermore, an energy balance formula including the influence of viscosity was newly constructed. We confirmed that the new formula agreed with the experimental results.

关键词： 高超音速飞行器  

ISBN: (纸本)9787561286678

摘要： 本书重点围绕高超声速空气动力学计算方法，结合相关典型空气动力学问题及应用开展研究。本书共分为9章，内容包括绪论，计算空气动力学基础，宽速域数值计算方法与高阶湍流模型，网格生成技术，高超声速边界层转捩数值模拟，高超声速热化学非平衡数值模拟，高超声速动导数数值计算，高超声速主动降热技术方案与数值模拟，宽速域高超声速飞行器气动布局设计等。

关键词： 中学数学课  

ISBN: (纸本)9787121463143

摘要： 本书是为中等职业学校毕业生参加职业教育单独招生统一考试而编写的冲刺阶段复习使用的模拟试卷。共收录了15套职业教育单独招生统一考试冲刺卷，较为全面地涵盖了职业教育单独招生统一考试涉及的知识点及题型。

摘要： While most synthetic polymers are best described by their statistical nature, many biological polymers derive their highly tailored functions from precisely defined monomeric sequences. Sequence-controlled polymers, such as polypeptoids, present a unique tool for controlling material properties by harnessing both the robustness of synthetic polymers and the ability to tailor the inter- and intra-molecular interactions so crucial to many biological materials. Significant progress has been made towards predicting how protein folding is controlled by monomer sequence and interactions with water, but a thorough understanding of how to use polymer sequence to similarly control chain conformation and resulting functionality in synthetic polymer assemblies is lacking. Similarly, advances in understanding the effect of polymer surface chemistry and topology on hydration water dynamics and resulting polymer-solute interactions lags behind analogous protein hydration studies. Together, the ability to control polymer structure and hydration water behavior via sequence-control offers an avenue to pursue polymeric materials with protein-like functionality. This work focuses on how polypeptoid sequence can be utilized to control polymer conformation and nearby water behavior. First, monomer sequence effects on polymer conformation are probed, primarily making use double electron-electron resonance (DEER) spectroscopy. Second, the sequence specificity of polypeptoids enables observation of multiple hydration environments within multi-chain assemblies via Overhauser dynamic nuclear polarization (ODNP) spectroscopy. Finally, these differences in water behavior are utilized to tune catalytic activity within micelles, much like proteins.

摘要： 一、借助大数据精准把握学情,提高讲评针对性 借助大数据, 可以清晰了解学生在考试中的答题情况. 笔者所在学校运用希沃评卷系统, 通过系统平台上的数据可以清晰地看到每个班的平均分, 各小题的平均分及得分率,每个学生每个小题的得分等,个体与整体的对比情况一目了然.借助大数据, 教师在课前能有效地备学情、备教法,把握好课堂讲解的重点和需要突破的难点, 在试卷讲评课中做到精准教学.

关键词： 壁湍流减阻   超疏水壁面   本征正交分解   尺度分解   相位平均  

摘要： 对超疏水微沟槽和微凸柱面湍流边界层的减阻机理进行了实验研究。使用高时间分辨率粒子图像测速仪(TRPIV),测量了亲水壁面、超疏水微沟槽壁面和超疏水微凸柱壁面湍流边界层内的瞬时速度场,对比分析了3种壁面的壁面摩擦切应力,发现超疏水壁面都产生了减阻效果,但超疏水微沟槽壁面的减阻率(13.8%)要大于超疏水微凸柱壁面(10.2%)。通过对比分析湍流边界层内3种壁面对应的平均速度剖面、湍流脉动强度和雷诺切应力剖面,证实流体在超疏水壁面具有滑移速度,且在15