信盒输送螺旋滑道主要设计参数确定

从理论上对信盒在螺旋滑道中的运动进行了分析，提出了螺旋滑道各设计参数间的条件公式，并绘出了参数曲线。     

膜式水冷壁立式成排弯管机设计

膜式水冷壁成排弯管机是锅炉制造的重要设备，文中归纳总结了国内外现有成排弯管机的弯制原理、弯管方式、设备结构、技术参数、机型和各自优缺点，在此基础上提出了适用于螺旋管圈膜式水冷壁成排弯管机的设计措施和有关计算方法，并进行分析比较，图14。     

A laplace-based spiral contouring method for general pocket machining

In this paper, a method for generating boundary-conformed pocketing toolpaths is developed. Based on the 2D Laplace parameterization of pocket contours and the redistribution of the original Laplace isoparametrics, continuous toolpaths are generated. These generated toolpaths have neither thin walls nor leftover tool marks. Detailed algorithms are formulated in steps. The method can be applied to general pockets either with or without islands. Some examples are provided to demonstrate the applicability of this method. In most cases, the method can successfully generate satisfactory toolpaths for arbitrary shaped pockets. However, according to the shape of the pockets and the distribution of the islands, when using this method, over machining may occur in some narrow or bottlenecked areas. Further investigation on how to alleviate this problem is needed. We believe that this method provides an alternative choice for pocket machining.     

旋风除尘器二维速度间的关系

在旋风除尘器中，混合气流是作螺旋线运动的。本文确定了水平切向速度与竖直上升速度之间的数量关系并列出了公式，对确定设备适当的结构和尺寸提供了实用的计算方法。     

强化姑山选厂二段磨矿分级的试验研究

针对姑山选厂二段分级效率低的问题，介绍了采用螺旋分级机－高频细筛串联分级和用高频细筛代替螺旋分级机两种工艺的试验情况。     

64层螺旋CT冠状动脉成像图像质量控制研究

目的:总结64层螺旋CT冠状动脉成像图像质量控制经验。方法:收集我院2012年6月-2013年7月进行冠状动脉血管造影检查的患者120例,使用AquilionTSX-101A64排CT进行检查。结果:本组120例患者中,有动脉亚段全部显示清晰79例,占65.8%;四个动脉亚段单一显示不清晰29例,占24.2%;动脉亚段均显示不清12例,占10.0%。结论:64层螺旋CT冠状动脉成像检查前控制好患者心率,选择最佳的重建时相窗,可以提高冠脉的成像质量。     

64排CT对食管癌外侵的评判及手术评估

目的:探讨64排CT在评价食管癌外侵、判断临床分期以及手术方案制定中的临床价值。方法:选择我院住院治疗的22例食管癌患者作为研究对象,所有患者术前采用64排CT检查,数据利用工作站进行处理分析。参考图像特征分析食管癌外侵的信号特点,并将CT分期与术后病理分期对比,进而分析其在评估手术方案中的作用。结果:管壁0.4-1cm的外侵率为16.7%(1/6);管壁1-2cm的外侵率为28.6%(2/7);管壁2cm的外侵率为77.8%(7/9)。CT结果判断可以手术切除而术中未能切除的患者有2例,预测准确性为90.9%。64排CT术前分期准确率为90.9%,且与病理学分期结果具有高度一致性。结论:64排CT对预测食管癌临床分期、评估手术方案有着重要作用,值得临床推广应用。     

滚珠型弧面凸轮分度机构的运动分析和仿真

滚珠型弧面凸轮分度机构中滚珠的运动影响到机构的润滑、失效形式和传动效率。滚珠中心、滚珠与凸轮滚道接触点及滚珠与分度盘球窝接触点相对于凸轮旋转轴线运动轨迹为螺旋曲线,计算表明3条曲线的螺旋升角大小不同。利用螺旋传动理论,分析滚珠的运动形式,计算滚珠的侧滑速度。应用RecurDyn软件对机构进行运动学仿真,验证了滚珠侧滑和锲紧的存在及负载转动惯量对分度盘运动规律的影响。     

基于二阶滑移边界的螺旋槽干气密封气膜刚度计算与分析

应用二阶非线性滑移边界条件推导出修正的广义雷诺方程,并用PH线性化方法、迭代法对非线性雷诺方程近似求解,得到气膜推力的近似解析式,继而对其进行气膜厚度的求导,得到气膜刚度的近似解析式.并利用Maple程序计算不同转速和压力下的气膜刚度数值,并与一阶线性滑移边界条件下的气膜刚度和试验数值进行对比.结果表明:随着气膜厚度的增加,二阶非线性滑移边界条件下的气膜刚度随之减小,且呈非线性关系:随着介质压力、转速的增加,气膜刚度也随之增加,且呈线性关系;二阶非线性滑移边界条件下的气膜刚度数值比一阶线性滑移边界条件下的气膜刚度数值更接近试验数值,其计算精度较高,特别是在低速、低压工况下更加明显.因此在低速低压釜用轴端干气密封中将应用二阶速度滑移条件下的流体力学理论来进行优化设计,指导工程应用.     

Influence of tooth modifications on tooth contact in face-hobbed spiral bevel gears

In this study the influence of tooth modifications induced by machine tool setting and head-cutter profile variations on tooth contact characteristics in face-hobbed spiral bevel gears is investigated. The concept of face-hobbed spiral bevel gear generation by an imaginary generating crown gear is applied. The modifications of tooth surfaces are introduced into the teeth of both members. The lengthwise crowning of teeth is achieved by applying a slightly bigger radius of lengthwise tooth flank curvature of the crown gear generating the concave side of pinion/gear tooth-surfaces, and by the variation of machine tool settings in the generation of pinion/gear teeth. The ease-off in the tooth height direction of meshing tooth surfaces is achieved by applying a head-cutter whose profile consists of two circular arcs, instead of a straight-line. The method of tooth contact analysis applied determines the path of contact, the potential contact lines, the separations along these lines, and the transmission errors. A computer program implements the method. By using this program the influence of the variation of machine tool settings and of head-cutter geometry on tooth contact is investigated and discussed.