一种立体织机平行打纬机构的设计与优化

针对多层织物织造过程中,各层纬纱打纬力需保持一致以及需要减少钢筘与纱线之间摩擦的要求,提出八连杆平行打纬机构,并根据工艺要求对打纬机构进行优化。以打纬机构的主轴转动140°时,筘座在后心位置处的近似静止位移Δs最小为优化目标,通过Matlab软件分析确定设计变量,优化钢筘在后死心位置的近似停留时间。运动学仿真结果表明,优化后的打纬机构不仅保证了钢筘的打纬动程和其在后死心处的静止时间,而且增大了钢筘的惯性打纬力,有利于厚重织物的打纬。     

Weaving hadamard matrices with maximum excess and classes with small excess

Weaving is a matrix construction developed in 1990 for the purpose of obtaining new weighing matrices. Hadamard matrices obtained by weaving have the same orders as those obtained using the Kronecker product, but weaving affords greater control over the internal structure of matrices constructed, leading to many new Hadamard equivalence classes among these known orders. It is known that different classes of Hadamard matrices may have different maximum excess. We explain why those classes with smaller excess may be of interest, apply the method of weaving to explore this question, and obtain constructions for new Hadamard matrices with maximum excess in their respective classes. With this method, we are also able to construct Hadamard matrices of near‐maximal excess with ease, in orders too large for other by‐hand constructions to be of much value. We obtain new lower bounds for the maximum excess among Hadamard matrices in some orders by constructing candidates for the largest excess. For example, we construct a Hadamard matrix with excess 1408 in order 128, larger than all previously known values. We obtain classes of Hadamard matrices of order 96 with maximum excess 912 and 920, which demonstrates that the maximum excess for classes of that order may assume at least three different values. Since the excess of a woven Hadamard matrix is determined by the row sums of the matrices used to weave it, we also investigate the properties of row sums of Hadamard matrices and give lists of them in small orders. © 2004 Wiley Periodicals, Inc. J Combin Designs 12: 233–255, 2004.     

纺织锭杆超精机PLC控制系统的设计研究

简要介绍了纺织锭杆超精机的设计思想，给出了自动控制系统的软硬件结构的设计方法，对纺织企业具有一定的参考价值．     

毛巾织物“斜坡”织疵形成机理及其克服措施

本文对毛巾织物织口后移、毛圈间距进行了定量分析,阐明了毛巾织物“斜坡”织疵产生的主要原因是两条毛巾之间因不同打纬动程之差形成的剪口大小与织一个毛圈织口的后移量不能相等。最后提出了改第一块平布稍短打纬平布为长打纬平布、级完第一块平布开始织毛圈时使卷取机构停卷二到三纬的措施。实践证明,效果良好。     

织造和染整加工前后精梳毛纱拉伸性能的关系

为了根据织造前纱线的拉伸性能和织造、后整理工艺预测织物的拉伸性能,研究了织造和染整加工前后精梳毛纱拉伸性能的关系,获得了三方面的结论:(1)经常规后整理加工的各种精梳毛织物中经纱的伸长变形能力没有显著差异,但其纬纱的伸长变形能力与织造和染整工艺有关。(2)坯布染色情况下织造前纱线的伸长变形曲线在伸长率方向扩大一定倍数以后与织物中纱线的伸长变形曲线相当。纱线染色情况下织造前纱线的伸长变形曲线的某一部分与织物中纱线的伸长变形曲线相当。(3)后整理加工中的经向张力和拉幅张力对精梳毛织物中纱线的伸长变形能力的影响特别大。树脂整理有降低织物变形特别是变形回复能力的作用。     

近代中国纺织业利用外资简述

本文对近代中国纺织业利用外资情况,分阶段地、简要地加以叙述和讨论。文中重点讨论和分析了棉纺织业举借外债的情况,汇集了1890年～1932年间贷款资料。     

不对称梭口对打纬阻力的影响

打纬时梭口处上下层经纱的张力差异对打纬阻力存在明显的影响。打纬时张力的差异(在文中以张力比来表示)愈大,打纬阻力就愈小。本文首先利用一个简单的数学模型,定性地比较在不同张力差异的条件下打纬阻力的大小,然后通过实验数据加以证实。     

论新时期电力档案数字化编研的发展及重要性

21世纪全球进入一个新经济时代,以网络和电子信息为主要特征的新经济以不可争辩的事实席卷全国的各个行业。新时期下电力部门应加强电力档案的资源与信息化的建设,加快档案信息的开发与利用,促使电力档案管理数字化编研工作积极参与到企业生产经营的各个方面,不断提高对电力档案管理数字化编研工作重要性的认识。     

AN ANALYSIS OF DYNAMIC PERFORMANCE OF BACK REST OF WEAVING MACHINERG

Periodic variations of warp tension during a weaving cycle results in corresponding variationsof back rest position.However,the oscillation of back rest,in turn,shows effect on the variation ofdynamic warp tension.As a force transfer medium,warp yarn,with specific dynamic performances,is certainly one of the factors influencing the movement of back rest.In this paper,warp yarn istreated as a viscoelastic medium in studying the dynamic behaviours of back rest.A mathematicalmodel of a back rest system is developed based on the automatic control theory.Several factors arelisted,which show influences on the performances of the back rest system.Analytical work is car-ried out to identify the effects on the frequency response of the back rest systen resulting from vari-ations of such parameters as the modulus of elasticity,of both fast-elastic and slow-elasticdeformations,and viscosity coefficient.