降低紧密纺色织物浆纱断头的几项措施

为了降低紧密纺色织品种的浆纱断头,提高产品质量,分析了该品种在浆纱过程中产生断头的原因,介绍了在操作方面应采取的措施及在工艺方面应注意的问题.通过适当加大干分绞区张力及前浆槽纱线的喂入张力、预烘张力,单独控制前浆槽的浆液粘度,确保回潮率满足工艺要求,有效解决了紧密纺色织品种浆纱断头问题,提高了织轴质量.     

化学结构式的拓扑描述

化学结构式的拓扑描述,是化学信息计算机化的手段之一。这里系统地建立了一整套的连接表(三类:紧缩连接表、冗余连接表、和连接方阵),用来进行结构式中原子之间连接关系的拓扑描述,对分子结构进行数值化。同时,阐述了连接表唯一化的方法,并介绍了不同类型连接表之间的转换关系和还原为平面结构式图形的绘图程序。     

加速国内电弧炉工艺技术的发展

提出以紧凑式电炉流程模式对国内电炉钢厂进行改造，以及加强大型电炉冶炼工艺技术研究的建议。     

紧凑 Tokamak(球形环)聚变堆第一壁及中心导体柱上中子负荷及核热计算与分析

采用通用蒙特卡罗粒子输运程序ＭＣＮＰ／３８计算低环径比Ｔｏｋａｍａｋ（紧凑环或球形环）聚变堆第一壁及中心导体上的中子壁负荷分布和核热沉积分布，并与常规Ｔｏｋａｍａｋ堆第一壁上中子壁负荷分布和核热沉积分布进行比较、分析。结果表明，在中子壁负荷归一化为１ＭＷ／ｍ２时，与常规Ｔｏｋａｍａｋ相比，在低环径比Ｔｏｋａｍａｋ堆第一壁及中心柱表面上中子壁负荷分布峰值并不比常规Ｔｏｋａｍａｋ堆第一壁上的峰值高，而且低于低环径比Ｔｏｋａｍａｋ堆整个第一壁上的平均值，而中心柱上的核热沉积峰值稍高于常规Ｔｏｋａｍａｋ堆第一壁上的核热沉积峰值，但对较高中子壁负荷情况，中心导体柱上的核热沉积和辐照损伤仍可能是比较严重和值得特别研究的问题。     

Design of noise and period-time robust high-order repetitive control, with application to optical storage

Repetitive control is useful if periodic disturbances or setpoints act on a control system. Perfect (asymptotic) disturbance rejection is achieved if the period time is exactly known. The improved disturbance rejection at the periodic frequency and its harmonics is achieved at the expense of a degraded system sensitivity at intermediate frequencies. A convex optimization problem is defined for the design of high-order repetitive controllers, where a trade-off can be made between robustness for changes in the period time and for reduction of the error spectrum in-between the harmonic frequencies. The high-order repetitive control algorithms are successfully applied in experiments with the tracking control of a CD-player system.     

Evaporative Heat Transfer of Annular Two-phase Flow of Air-water in a Small Vertical Tube

The evaporative heat transfer of the non-boiling annular two-phase flow of air-water in a small vertical tube with uniform wall heat flux was studied both theoretically and experimentally. A simplified two-phase flow boundary layer model was used to calculate the thickness of the water film attached to the wall, and from the liquid film thickness the evaporative heat transfer coefficients of the annular two-phase flow were obtained. Theoretical equations and semi-theoretical equations were proposed for predicting the evaporative heat transfer of the annular two-phase flow of air-water in a small vertical tube. The semi-theoretical prediction agrees well with the experimental data. The mechanism of the heat transfer enhancement is the evaporation of the thin liquid film attached on the wall.     

Effect of gas composition on cementite decomposition and coke formation on iron

Cementite decomposition and coke formation in the metal dusting process of iron were investigated at 700 °C in CO-H₂-H₂O gas mixtures. The presence of graphite deposited on the surface initiates the decomposition of cementite into iron and graphite. The morphology of the reaction products varies with gas composition. For CO concentrations less than 5 vol%, particles of iron or even closed iron layers have been observed at the cementite/graphite interface. With increasing CO content the amount of iron in the interface decreases. At CO concentrations higher than 30 vol%, iron could not be detected at the interface by optical microscopy. Thermo-gravimetric analysis shows that the rate of carbon take-up increases with increasing CO concentration reaching a maximum at about 60-75 vol%.The morphologies of graphite in the coke layer can be identified as three types: porous graphite clusters with embedded iron-containing particles, compact bulk graphite with a uniform thickness and a columnar layered structure, and filamentous carbon with iron-containing phases at the tip or along its length. For gas mixtures with low CO concentrations, e.g. 5 vol%, porous graphite clusters are the main form of carbon although filamentous carbon can be seen at the early stage of reaction. With increasing CO concentrations to, e.g. 30 vol%, a compact bulk graphite is formed on the top of the surface. Under this compact graphite, there is an inner layer of graphite which is the combination of porous graphite clusters and filaments. These two layers of graphite are clearly distinguishable when CO content reaches more than 75 vol%. In this case, the main form of graphite in the inner layer is filamentous carbon. The compact graphite layer suffers a serious deformation and forms many cracks because of the growth of catalytic filamentous carbon underneath. These filaments grow outside from compact graphite crevices and finally cover the whole surface. The higher the CO content in the gas, the more the tendency of filamentous carbon formation. The interplay between morphologies of carbon formation and metal dusting has been discussed.     

某车载导弹轮胎支撑发射仿真研究

在某车载导弹发射时轮胎支撑问题的研究中,为能够提高武器系统的应急性和实用性,并验证轮胎支撑发射的可能性,利用Brushing约束解决了适配器与导弹的约束问题,利用控制程序实现导弹连发和解锁,在ADAMS软件里进行了可视化动力学仿真,建立3种轮胎支撑模型,弹簧阻尼模型、碰撞模型和UA轮胎模型,通过轮胎与地面的相互作用力的比较,论证建立模型的可信性.对比不同支撑模型下发射车质心运动参数和发射架运动参数,及导弹出筒后下沉量和俯仰方向运动参数,得到轮胎支撑发射是可行的.