跨声速机翼抖振初始迎角N-S方程定常计算分析

 应用代数法和椭圆型方程优化相结合的方法生成翼身组合体块结构网格。采用有限体积空间离散法和五步Runge-Kutta显式时间推进法求解N-S方程。基于雷诺平均N-S（RANS）方程,选用Spalart-Allmaras（SA）一方程模型模拟紊流。根据N-S方程定常计算结果,采用升力曲线、俯仰力矩曲线、后缘压力发散、跨声速激波位置以及机翼表面极限流线等几种判据,对跨声速机翼的抖振初始迎角进行了合理的预测分析。     

Morphology and Frictional Characteristics Under Electrical Currents of Al203/Cu Composites Prepared by Internal Oxidation

Two AhO3/Cu composites containing 0.24 wt.% A1203 and 0.60 wt.% A1203 separately are prepared by internal oxidation.Effectsof sliding speed and pressure on the fi-ictional characteristics of the composites and copper against brass are investigated and compared.The changes in morphology of the sliding surface and subsurface are examined with scanning electron microscope (SEM) and energy dispersive X-ray spectrum (EDS).The results show that the wear resistance of the AI203/Cu composites is superior to that of copperunder the same conditions.Under a given electrical current,the wear rate of AI203/Cu composites decreases as the AleO3-content increases.However,the wear rates of the Al203/Cu composites and copper increase as the sliding speed and pressure increase under drysliding condition.The main wear mechanisms for AleO3/Cu composites are of abrasion and adhesion;for copper,it is adhesion,although wear by oxidation and electrical erosion can also be observed as the speed and pressure rise.     

基于电子展成与坐标结合原理自动测量圆柱齿轮的研究

介绍了利用电子展成与坐标结合的原理来自动测量渐开线圆柱齿轮的方法。采用CNC技术实现电子展成 ,利用被测齿形的测量值进行分析与评价。为了消除传动误差 。     

Assessing ecohydrological factors variations and their relationships at different spatio-temporal scales in semiarid area,northwestern China

As a typical semiarid farming-pastoral ecotone sensitive to the environmennt, the Plain of West Liaohe Basin (WLBP) is currently experiencing drastic environmental changes. To identify how environmental change affect vegetation in the WLBP, we analysed spatiotemporal variation characteristics of Ecological environment factors based on monthly and annual air temperature (T), precipitation (P) and Normalized Difference Vegetation Index (NDVI) from 1982 to 2015. And the correlations between them were investigated by correlation analysis (Simple correlation, partial correlation and complex correlation) at temporal and spatial scale. The results showed that: (1) the vegetation growth of the WLBP showed ameliorated trend, with a change rate of 0.004/yr.; (2) P was more sensitive to NDVI than T; (3) and the influence of hydrothermal changes on vegetation growth was more significant than that of the change of single climate factors at time scales; (4) the effects of anthropogenic factors on vegetation change were 75.07% (1982–1993) and 98.08% (1994–2015), respectively. At the temp-special scales, P&T and land use type change (LUCC) were the main climatic and anthropogenic factors that affect vegetation changes, respectively.     

从《四书章句集注》看构建和谐社会

《四书章句集注》比较典型地反映了宋明理学思想。对于理学思想对后世的毒害,论述者很多。较有影响的是戴震的“以理杀人”的论断。但理学思想是不是就是思想史上一堆毫无价值的破烂呢?在价值判断呼唤多元化的今天,倒澡盆里的脏水连同小孩一块倒出去的做法显然已变得可笑。朱熹写作《四书章句集注》花了四十余年,可谓穷毕生之力。在他的写作过程中,理学尚未成为被官方认可的意识形态,也还未成为士人读书应考的必读内容,他更多的仍是一种尚未被扭曲思想领域的纯粹思辩,是宋代知识分子企图通过“道统”来参与“政统”的一种努力。因此,在对《…     

人机标准陆空通话系统

陆空通话是航指挥的基本功，它为航管人员与飞行员信息勾通架起一座桥梁。本文介绍利用计算机多媒体技术开发的人机标准陆空通话自学习系统，它可以根据学员自身的学习效果，控制学习进度。该系统可以有效地促进、提高学员的听说能力。     

试论QC小组与质量改进的关系

介绍ＱＣ小组的产生和ＩＳＯ９００４－４《质量改进指南》标准的提出，阐述了ＱＣ小组与质量改进的关系。     

载波捕获防错锁技术新探

应我国微波统一测控系统设备中存在的载波捕获错锁问题展开讨论，并对目前防错锁方法的优劣进行了分析，在分析和研究前人工作的基础上，提出了载波能量中心防错锁算法。     

OPTIMIZATION DESIGN OF HELICOPTER FOR PRELIMINARY PARAMETERS

ＯＰＴＩＭＩＺＡＴＩＯＮＤＥＳＩＧＮＯＦＨＥＬＩＣＯＰＴＥＲＦＯＲＰＲＥＬＩＭＩＮＡＲＹＰＡＲＡＭＥＴＥＲＳＧｕｏＣａｉｇｅｎ（ＴｈｅＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＨｅｌｉｃｏｐｔｅｒＴｅｃｈｎｏｌｏｇｙ，ＮａｎｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏ...     

金属基高功率CO2激光沉积超硬Si3N4膜层性能研究

本文采用高功率ＣＯ２激光在金属基材汽相沉积出厚度－３０μｍ标准化学计量配比、平均硬度达２２００ＨＫ的ａ－Ｓｉ３Ｎ４膜层，与基材有良好的结合界面，实验分析表明所沉积膜具有超硬和良好的耐磨抗蚀等性能。