如何在C语言教学中帮助学生树立信心

该文对C语言教学中两种不同的教学思路做了举例、分析和比较,偏重算法的教学有助于培养学生研究算法编制程序的能力,但对初学者培养兴趣、树立信心方面没有益处,在这方面偏重语法的教学更有效率,建议在教学实践中注重两者的结合。     

Epsilon-near-zero or mu-near-zero materials composed of dielectric photonic crystals

We theoretically demonstrate that at certain frequencies two-dimensional dielectric photonic crystals （PCs） may be regarded as either epsilon-near-zero or mu-near-zero materials. We show that the transmission through a slab of such materials upon normal incidence is normally non-unity and decays with slab thickness. However, when the incident angle increases slightly, the transmittance experiences a dramatic increase due to the Brewster effect. The combination of the tunneling and resonance effects makes such materials good candidates for almost perfect bending waveguides and cloaking in waveguides. The zero index also enables applications of focusing and directive emission. At last, the distinction between the single-zero and double-zero media is discussed. In all of the above results, the numerical simulations perfectly match with theoretical predictions from the effective medium analysis.     

运用多媒体改革经济数学教学存在的问题与对策

如何将多媒体技术有效地应用于经济数学课堂教学中,是目前经济数学教学改革值得注意的问题。结合教学实践,分析当前经济数学多媒体教学存在的问题,提出经济数学课程使用多媒体教学必须结合课程的特点,教学的需要以及学生的实际情况,将传统黑板教学与多媒体教学优势互补,以实现最佳教学效果。     

基于混合式结构的无线Mesh网的改进AODV路由协议

对AODV协议做了一些改进,通过优先使用Mesh路由器来传送报文．以充分利用混合结构的异构性。为了实现多射频Mesh网络的通道多样性和减少干扰．设计了一个简单的通道选择机制。     

非线性切换系统的集合稳定性分析

将输出对状态稳定和状态模可观测等概念进行推广.提出了输出对V(x)稳定、小时间y(z)可观测、大时间V(x)可观测的定义.利用上述定义,给出了非线性切换系统的V(x)零值集稳定的充分条件.分别利用统一Lyapunov函数和多Lyapunov函数证明了所提出的结论,并详细讨论了输出对V(x)稳定与输出对状态稳定及其他相关定义之间的关系.数值例子验证了所提出结论的正确性.     

基于PLC的电梯控制系统的设计与实现

采用FX2N-48MR三菱PLC作为电梯的控制系统,应用于透明仿真教学中,从电梯控制系统的结构组成及其设计思路和具体的硬件设计软件设计,说明如何实现一个电梯控制系统。     

文科大学生计算机课程设计性实验的研究与实践

将现代项目管理理念引入教学,并将这一理念应用于Visual Foxpro程序设计课程的教学实践。通过在文科类大学生计算机课程教学中设计性实验的实施,阐述了实施设计性实验的意义,总结了教学实践中遇到的问题,探究了问题存在的原因,并提出了解决问题的一些设想。     

一种气象卫星数据脉冲噪声滤除方法

气象卫星数据在采集或者传输的过程中,往往会引入不同程度的脉冲噪声。为提高图像质量,滤除噪音,进行可信度分析,提出了一种三阶段气象卫星数据脉冲噪声检测和滤除方法。在算法第一阶段,利用均值与均方差比值差值序列建立排序检测器(ROD),检测出图像中所有可能的脉冲噪声点;第二阶段,采用逐点滑动N×N窗口,按照每个可能的脉冲噪声点在不同的滑动窗口被重复检测到的次数,建立噪声可信度。第三阶段,对高噪声点进行滤波;对低噪声点迭代排序检测,如果可识别有噪声点,再进行滤波。结果表明,算法可以准确检测和滤除脉冲噪声,并保持数据中非噪声点信息。     

Critical Review of Fluorinated Electrolytes for High-Performance Lithium Metal Batteries

Lithium metal batteries (LMBs), due to their ultra-high energy density, are attracting tremendous attentions. However, their commercial application is severely impeded by poor safety and unsatisfactory cycling stability, which are induced by lithium dendrites, side reactions, and inferior anodic stability. Electrolytes, as the indispensable and necessary components in lithium metal batteries, play a crucial role in regulating the electrochemical performance of LMBs. Recently, the fluorinated electrolytes are widely investigated in high-performance LMBs. Thus, the design strategies of fluorinated electrolytes are thoroughly summarized, including fluorinated salts, fluorinated solvents, and fluorinated additives in LMBs, and insights of the fluorinated components in suppressing lithium dendrites, improving anodic stability and cycling stability. Finally, an outlook with several design strategies and challenges will be proposed for novel fluorinated electrolytes.     

Designing Metallic and Insulating Nanocrystal Heterostructures to Fabricate Highly Sensitive and Solution Processed Strain Gauges for Wearable Sensors

All‐solution processed, high‐performance wearable strain sensors are demonstrated using heterostructure nanocrystal (NC) solids. By incorporating insulating artificial atoms of CdSe quantum dot NCs into metallic artificial atoms of Au NC thin film matrix, metal–insulator heterostructures are designed. This hybrid structure results in a shift close to the percolation threshold, modifying the charge transport mechanism and enhancing sensitivity in accordance with the site percolation theory. The number of electrical pathways is also manipulated by creating nanocracks to further increase its sensitivity, inspired from the bond percolation theory. The combination of the two strategies achieves gauge factor up to 5045, the highest sensitivity recorded among NC‐based strain gauges. These strain sensors show high reliability, durability, frequency stability, and negligible hysteresis. The fundamental charge transport behavior of these NC solids is investigated and the combined site and bond percolation theory is developed to illuminate the origin of their enhanced sensitivity. Finally, all NC‐based and solution‐processed strain gauge sensor arrays are fabricated, which effectively measure the motion of each finger joint, the pulse of heart rate, and the movement of vocal cords of human. This work provides a pathway for designing low‐cost and high‐performance electronic skin or wearable devices.