复合材料航空机载雷达天线罩电性能设计技术研究

本文主要讨论了复合材料雷达天线罩设计的基本理论、计算方法,介绍了一种单层罩壁天线罩的电性能——结构强度综合设计方法,通过对天线罩的电磁特性分析,应用射线跟踪法,按照最大传输准则和准对称相位方法确定单层罩壁的最佳壁厚。     

重庆菜园坝大桥缆索吊机电气控制设计

介绍了PLC在重庆菜园坝大桥缆索吊机电气控制设计中的应用，提出了在设计中应引起注意的几个问题。     

Testing results analysis of contact materials’electrical contact performance

Because of the different ways in which contact materials work, the basic requirements for silver metal oxide contact materials are different. They are anti-welded and anti-erosion when closed, anti-erosion when broken, and arc easily moved and have smaller contact resistance. In this paper, La2O3 is used as a stable oxide in contact material to replace CdO. A new type of Ag/SnO2-La2O3-Bi2O3 contact material is first obtained through using powder metallurgical method. Then electrical contact material parameter tester is used to test the electrical contact performance of the contact material. Through experiments, the arcing voltage and current curves, arcing energy curves, fusion power curves while broken and contact resistance while closed were obtained. Analysis of the results showed that the addition of La2O3 makes the contact material have the following advantages: smaller electrical wear, smaller arc energy, smaller contact resistance and arc is more easily extinguished.     

中国古代的合朔推步算法分析

朔是中国古代天文学中一个十分重要的概念.给出定朔算法的现代模型和重建模型,并依此分析中国古代历法中的合朔推步算法,梳理了从《乾象历》到《大统历》中国传统历法中合朔算法的变化和演进过程,指出中国古代大多数历法的合朔算法都是不完整的,仅有《大业历》、《皇极历》和《大统历》等少数几部历法的算法与重建模型一致.     

高职高专《电工电子操作技能项目化实训教程》教材建设研究

教材是教师传授知识的载体,是学生学习知识的依据。高质量教材是培养高素质技能型人才的基本保证。《电工电子操作技能项目化实训教程》采用工作过程导向的项目化教材编写思路,在企业调研、工作任务分析、典型工作任务归纳的基础上,选择企业真实工作任务作为教材编写项目,同时融入＂电工操作证考试＂和＂初级电子仪器仪表装配工技能考核＂职业技能鉴定标准,使教材内容与职业资格证书制度有效衔接。     

“汽车电器与电子设备”课程教学改革尝试

高职"汽车电器与电子设备"课程采用传统的教学内容和方法已跟不上汽车电器技术的发展需要。因此,应选择符合时代要求的教学内容,改革教学方法,注重对学生能力的培养,加强实践教学,改革考核方式,以培养符合时代要求的高技能高职汽车电器人才。     

Quantitative mean square exponential stability and stabilization of stochastic systems with Markovian switching

This paper is concerned with the quantitative mean square exponential stability and stabilization for stochastic systems with Markovian switching. First, the concept of quantitative mean square exponential stability(QMSES) is introduced, and two stability criteria are derived. Then, based on an auxiliary definition of general finite-time mean square stability(GFTMSS), the relations among QMSES, GFTMSS and finite time stochastic stability (FTSS) are obtained. Subsequently, QMSE-stabilization is investigated and several new sufficient conditions for the existence of the state and observer-based controllers are provided by means of linear matrix inequalities. An algorithm is given to achieve the relation between the minimum states’ upper bound and the states’ decay velocity. Finally, a numerical example is utilized to show the merit of the proposed results.     

A new distributed Kalman filtering based on means-quare estimation upper bounds

In this paper, a novel distributed Kalman filter consisting of a bank of interlaced filters is proposed for a signal model whose dynamic equation and measurement equation are coupled. Each of the interlaced filters estimates a part of state rather than the global state using its and its neighbor information, which is different from other distributed filters already existed (e.g., distributed Kalman filter based on diffusion strategy or consensus strategy, distributed fuzzy filter and distributed particle filter with Gaussian mixer approximation, etc). This relieves the calculation and communication burden in networks. In addition, the proposed distributed Kalman filtering contains no consensus strategies, which is useful in some cases since consensus usually requires an infinite number of iterations.     

Stability analysis of continuous-time systems with time-varying delay using new Lyapunov–Krasovskii functionals

This paper studies the stability of linear continuous-time systems with time-varying delay by employing new Lyapunov–Krasovskii functionals. Based on the new Lyapunov–Krasovskii functionals, more relaxed stability criteria are obtained. Firstly, in order to coordinate with the use of the third-order Bessel-Legendre inequality, a proper quadratic functional is constructed. Secondly, two couples of integral terms $\{{\int }_{t?h_t}^{s}x\left(s\right)ds,{\int }_s^{t}x\left(s\right)ds\}$ and $\{{\int }_{t?h_M}^{s}x\left(s\right)ds,{\int }_s^{t?h_t}x\left(s\right)ds\}$ are involved in the integral functionals ${\int }_{t?h_t}^t(·)ds$ and ${\int }_{t?h_M}^{t?h_t}(·)ds,$ respectively, so that the coupling information between them can be fully utilized. Finally, two commonly-used numerical examples are given to demonstrate the effectiveness of the proposed method.     

Google Calendar在成人学习时间管理中的应用

作为社会工作者、家庭承担者、学习者等多重社会角色的成人,在其学习过程中,面临着渴望学习但学习时间受限且安排不合理的困境。学习时间不够、时间不合理安排,显然成为成人学习过程中一个亟待解决的问题。成人只有协调好各方面的时间分配问题,才能保证学习的顺利开展。本文从应用的角度阐述了成人如何利用Google Calendar为平台工具进行学习时间的管理。