虚拟机械零件库的研制及应用

通过虚拟机械零件库的作用以及它在教学改革中的应用,阐述了虚拟机械零件库的特点及制作过程,说明了该零件库在培养学生设计能力、提高教学质量起到的积极促进作用.     

用微分法推导拉压静不定变形谐调方程

材料力学中，解决桥架拉压静不定问题时，推导变形谐调方程是其关键，以往都是用图解法近似导出变形谐调方程，本文作者提出用微分法导出普遍适用的变形谐调方程：△ｌ１＋△ｌ２＝２△３ｃｏｓα。     

双平衡环动力调谐陀螺的正交不平衡力矩

讨论了单平衡环动力调谐陀螺的正交不平衡力矩及其引起的漂移误差；完善了一些文献中给出的计算方法和公式；然后讨论了双平衡环动力调谐陀螺正交不平衡力矩的计算。     

四酚基乙烷环氧树脂的固化性能

研究了甲基四氢邻苯二甲酸酐(Me THPA)和4,4-二氨基二苯基砜(DDS)两种固化剂对1,1,2,2,-四(对羟基苯基)乙烷四缩水甘油醚环氧树脂(TGE)固化反应及固化性能的影响。通过DSC研究了树脂的固化行为,结果表明Me THPA体系与DDS体系的固化反应活化能分别为65.8和68.4 k J/mol;同时通过DMA、TGA以及万能材料试验机等方法对树脂的热力学和力学性能等进行研究。Me THPA体系的Tg为188℃,初始热分解温度为219.9℃,拉伸强度为33 MPa,弯曲强度为48 MPa。而DDS体系的Tg为203℃,初始分解温度为292.3℃,拉伸与弯曲强度分别为61和93 MPa。     

An aviation oxygen supply system based on a mechanical ventilation model

At high altitudes, an Aviation Oxygen Supply System(AOSS) protects pilots from low pressure and hypoxia by continuously providing oxygen corresponding to the pilots' dynamic respiratory properties.An AOSS mainly consists of oxygen supercharging machines which are used in a high-altitude flight cabin to supply pressurized oxygen to pilots.Therefore, it is of great significance to study the airflow dynamic characteristics of an AOSS for safe, continuous, and efficient oxygen supply.In this paper, an AOSS is firstly simplified and considered as a mechanical ventilation system.Then, its corresponding mathematical model is constructed.Next, to verify the mathematical model, a prototype AOSS with a lung simulator is proposed for an experimental study.Afterwards, to build a foundation for the optimization of the AOSS, the airflow dynamic characteristics of an aircraft are analyzed, and the effects of key parameters on the respiration system are researched.Through experimental and simulation studies, it can be concluded that the mathematical model is effective.Subsequently, for stability during the respiration process, we consider setting the equivalent throttling areas of the inspiration and expiration pipelines smaller within certain limits; additionally, an excessively high oxygen supply pressure will disturb smooth airflow, and in a low-pressure environment, the pressure can be 84 cm H_2O lower than the standard atmospheric pressure.This research can be referred to in the design of an oxygen supply system and the study on optimization of airflow dynamic characteristics.     

夸克磁共振及磁共振治癌

主要提出了以下学术观点：①粒子世界中并不存在强相互作用，夸克休系是自由旋着的夸克在电磁－弱相互作用下产生的进动维系稳定的；②物质的质量源于夸克的质量，夸克的质量又源于它的自旋。自旋转速不同，能量不同，质量就不同；③用高能粒子碰撞分离出自由夸克很难，但用夸克磁共振（ＱＭＲ）分离出自由夸克却很容易；④利用纵向驰豫时间的差别，使ＱＭＲ仅在肿瘤组织内分离出自由夸克，就可在治癌的同时，不伤及正常组织，从而为     

一类应力强度因子新公式的实用价值

通过与有限元等数值方法及实验结果的比较，说明了关于两共线半无限裂纹问题的新应力强度因子公式的重要工程实用价值，同时也说明国内外重要工程手栅中的相应旧公式不能解决实际工程问题。     

SPECIAL HIGH-ORDER BENDING CRACK TIP FINITE ELEMENT FOR THE REISSNER PLATE

ＳＰＥＣＩＡＬＨＩＧＨ┐ＯＲＤＥＲＢＥＮＤＩＮＧＣＲＡＣＫＴＩＰＦＩＮＩＴＥＥＬＥＭＥＮＴＦＯＲＴＨＥＲＥＩＳＳＮＥＲＰＬＡＴＥＪｉａｎｇＣｈｉｐｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＦｌｉｇｈｔＶｅｈｉｃｌｅＤｅｓｉｇｎａｎｄＡｐｐｌｉｅｄＭｅｃｈａｎｉ...     

三维波动板加速运动的推进性能研究

本文基于非惯性系中的线性非定常势流理论,利用非定常涡环面元法在时域内分步求解了三维波动板沿直线作加速运动时的绕流问题,讨论了波板的推进性能与波动的无量纲相速度、展弦比和运动加速度等因素的关系,以此模拟鱼类加速平游状况。     

测定应力强度因子的守恒积分┐光弹性法

提出了测定断裂力学中应力强度因子的守恒积分－光测弹性力学方法,推导了守恒积分中位移梯度的应力分量表达式,从而可由应力光图所提供的信息计算守恒积分,并确定应力强度因子．本方法克服了单参数法与双参数法固有缺点．由此所得结果与由边界配置法所得结果非常一致．