工程陶瓷的加工技术

主要介绍了国内外工程陶瓷特种和常规加工技术的开发及应用近况。     

高精度算术运算

本文针对当前各种计算机高级语言运算精度的不足，用PASCAL语言实现了高精度的加、减、乘、除算术四则运算。以满足教学、科研的实际需要。     

历经十年寿命试验的消旋天线机构轴承的可靠性分析

解决了一个计算可靠性问题的特例。分析了消旋天线机构轴承历经10年寿命试验的可靠性问题。并给出了轴承在不同可靠寿命要求下的可靠度(对应不同置信度)。     

新建他激反激变换器方程及其解析解

引用文 [1 ]的思路 ,寻找他激反激变换器的运行状态特征参量 (磁通密度增量、剩余磁通密度和占空比 )与构成这一变换器的基本物理参量之间的函数关系。首先阐明由于频率给定 ,他激反激变换器稳态运行时会出现无剩磁工况和有剩磁工况两种。而后确定这两种工况下 ,磁路等效储能空间单位体积每个周期的传输能量 (命名为“磁能传输密度”)。在这基础上 ,分别建立和解出他激反激变换器在不同工况下稳定运行时应满足的方程。最后根据所得的解析解阐明这种变换器的特性。本文和文 [1 ],以磁路分析为基础建立了一种新的反激变换器理论。     

杨振宁的科学研究艺术

杨振宁教授是位著名的物理学家，诺贝尔物理学奖金获得者。他在物理学研究中取得的成就同科学研究的艺术是分不开的。本文分析了如下三个问题：第一“对称性支配相互作用”与杨米尔斯规范场理论；第二，科学研究中的风格和ｔａｓｔｅ；第三，科学研究方向的选择。该文无论是对年青的研究还是对成熟的学者从事科学研究都有指导意义。     

拓宽周转齿轮系的应用

本文为拓宽创新设计机构的思路,扼要地介绍了一种利用空间周转轮系,实观机械手臂的公转与自转动作要求的机构运动分析、设计方案及结构参考图。     

阻尼材料在飞机炮振减振上的应用

阻尼材料在飞机结构上的应用是一个新课题。在飞机炮舱区应用新型阻尼材料,组成一个全新的阻尼结构系统来吸收由航炮射击时产生的冲击能量,以实现减振的设计目的,进而改善其炮击的振动环境。通过理论计算和地面试验实测,证明了应用新型阻尼材料可使炮舱区的动应力下降近30％。     

J—7LP飞机1：6遥控模型失速尾旋试验

对无动力J—7LP动力学缩比模型进行了遥控试飞,以研究其失速尾旋特性,全偏平尾和方向舵可使模型进八尾旋,舵面全回中即可从各种尾旋中改出。偏转副翼对尾旋特性有明显的影响。     

英语课堂教学中学生的厌烦心理及其分析

分析英语课堂教学中学生厌烦心理，转变教学观念，培养学生学习兴趣，真正发挥课堂教学的作用。     

Reconstructed 3-d magnetic field structure and hard X-ray two ribbons for 2000 Bastille-day event

The Bastille-day event in 2000 produced energetic 3B/X5.6 flare with a halo CME, which had great geo-effects consequently. This event has been studied extensively and it is considered that it follows the two-ribbon flare model. The flare/CME event was triggered by an erupting filament and TRACE observations showed formation of giant arcade structures during the flare process. Hard X-ray (HXR) two ribbons revealed for the first time in this flare event (Masuda et al., 2001). The reconstruction of 3-D coronal magnetic fields revealed a magnetic flux rope structure, for the first time, from extrapolation of observed photospheric vector magnetogram data and the flux rope structure was co-spatial with portion of the filament and a UV bright lane (Yan et al., 2001a, 2001b). Here we review some recent work related to the flux rope structure and the HXR two ribbons by comparing their locations and the flux temporal profiles during the flare process so as to understand the energy release and particle accelerations. It is proposed that the rope instability may have triggered the flare event, and reconnection may occur during this process. The drifting pulsation structure in the decimetric frequency range is considered to manifest the rope ejection, or the initial phase of the coronal mass ejection. The HXR two ribbons were distributed along the flux rope and the rope foot points coincide with HXR sources. The energy dissipation from IPS observations occurred within about 100 R _⋅ is consistent with the estimate for the flux rope system. This revised version was published online in August 2006 with corrections to the Cover Date.