棉纤维表面比电阻和含水率的关系

电阻定律是对粗细均匀的导体而言的,它是一个实验定律,其数学表达式为:R=ρ_v1/S (1)这就是说,一段粗细均匀导体的电阻与该段导体长度成正比,与其横截面积成反比,比例系数ρ_v称为电阻率。因为ρ_v与材料的长度及横截面有关,习惯上又称为体积比电阻。     

方块电阻

本期“非织造布磁控溅射镀银的导电和抗紫外性能”一文中,处理织物的导电性能是通过测量其方块电阻进行衡量的。那么,何为方块电阻呢？简单来说,方块电阻（Sheet Resistance）就是指导电材料单位厚度单位面积上的电阻值,     

6CLZ—600型往复理条机的维护与保养

１结构、用途与特点６ＣＬＺ６００型往复（电热）理条机结构如图所示，其主要技术参数列于表１。６ＣＬＺ６００型往复理条机结构示图表１６ＣＬＺ６００型电热理条机主要技术参数项目技术参数往复频率２００次／ｍｉｎ配用电机功率０５５ｋＷ电热远红外管功率５...     

保健白菜干加工工艺技术

白菜属十字花科草本植物白菜和青菜的幼株。其生势旺盛，适应性强；而且质嫩爽脆，营养丰富。据分析，每１００ｇ鲜料中含１５ｇ蛋白质、０３ｇ脂肪、２３ｇ糖类、９３ｍｇ钙、５０ｍｇ磷、１６ｍｇ铁、１４ｍｇ胡萝卜素、００３ｍｇＶＢ１、００８ｍｇＶＢ...     

电力系统中变电站地网设计探讨

多数变电站建于土壤状况复杂地区,如何根据实际的不均匀土壤,结合新的施工工艺,在面积有限、土壤电阻率较高地区设计出符合国家规程规定的接地系统是保障电力系统运行人员和设备安全的一项重要工作。本文分析了关于高土壤电阻率地区变电站接地系统的接地电阻很难满足规程要求的问题,结合工程实例讨论了变电站的接地网设计方案。     

凤凰山雷达站防雷接地系统设计及防雷效果分析

土壤电阻率高地区接地装置的接地电阻难以达到规范要求,运用等效半球体接地原理,在岩石缝隙内打接地极,埋设垂直接地体,并采用降阻剂压力灌浆工艺进行降低接地电阻,取得良好降阻效果。经多年实践使用,接地电阻值一直都很稳定,使用效果非常好,为高山雷达站接地系统降阻提供了宝贵经验。     

草莓带肉果汁的榨取及无菌贮存技术

草莓带肉果汁的榨取及无菌贮存技术林涛草莓是广大消费者喜爱的时令水果，其色泽鲜艳诱人、肉质细嫩、酸甜适度、味美可口，是水果中的佳品。草莓营养丰富，据分析其果实中含糖５～１０％、有机酸０５～１４％、果胶０７％、以及大量的矿物质和维生素，如每１００ｇ...     

电热膜制造中的丝网印刷

电热材料除传统的诸如镍铬合金(合金丝和由该丝织成的金属布)外,新的电热陶瓷和导电性高分子复合物体系已开始普及应用。这种电热材料的核心是一层薄薄的导电涂膜。将该膜做成一定的电阻,应用丝网印刷或涂布的方法将其印刷或喷涂附着在适宜的基材上,连接膜上的电极并通入低电压电流时,热量立刻从膜内释放出来。这种电热材料加工方便、无污染、安全性好、电热转换效率高、耗电少、节能显著,是一种比较理想的电热材料,已在众多领域中广泛应用。电热膜的主要特点电热膜是一种通电后能发热的半透明聚酯薄膜,可导电的特制油墨、金属截流条经印刷,…     

烟尘比电阻对碱炉和电除尘器的影响

１烟尘比电阻和烟尘成分含量的分析１１烟尘比电阻定义烟尘比电阻是烟尘在电场烟道中流动，每厘米长度烟尘表面积导电所具有的电阻，单位为Ω·ｃｍ。１２烟尘成分含量的分析《电除尘器专辑》介绍，烟气温度＜３００℃时，烟尘表面积导电成为主要机理，对水分及化学膜...     

老分度号数显仪表的改制

1配热电阻数显仪表测温原理 热电阻的电阻值随温度的变化而变化，配热电阻的数显测温仪表就是利用其电阻值与温度的这种对应关系，将热电阻作为一次感温元件，由数显测温仪表对电阻信号进行处理后，实现对温度的测量和控制。数显测温仪表必须与相应分度号的热电阻配套使用，否则是无法进行正常测量的。     

面料性能对平领重叠量及造型的影响

选用15种常见面料,采用文化式原型制作衣身样板,根据面料的不同特点,选用不同的重叠量,共绘制了11付领片纸样.通过分析研究平领重叠量与面料性能之间的关系,得出:在面料被测的参数中,厚度与重叠量的相关性最强,其次是经密、纬密、抗弯刚度、悬垂系数和面密度(其中,除经密、纬密与重叠量呈正相关外,其余均呈负相关关系);用于预测...     

Ni-Ti形状记忆合金纤维相变的电阻特性

相变温度是决定形状记忆合金纤维的加工与使用的重要性能参数。以Ni-Ti合金纤维为例,为研究其相变过程中温度与电阻之间的关系,基于纤维内部马氏体生长模型和电阻的混合定律,建立了Ni-Ti合金的电阻特性模型,研究了自由状态下Ni-Ti纤维电阻率与温度之间的关系。设计电阻法温度测量装置及信号采集系统,对自由状态下的Ni-Ti纤维进行测试,通过对纤维电阻率-温度曲线求导,测得Ni含量为55.5 a.t.%纤维试样的四个相变温度分别为Ms=34.4℃,Mf=25.6℃,As=39.4℃,Af=51.1℃,与纤维DSC法测试结果对比发现：通过电阻、温度的同步测量可以有效地探测纤维的相变,相变温度可通过电阻率-温度导函数准确标定。     

服装局部热阻与总热阻的动静态关系及其模型

为研究人体在静止站立和行走时服装局部热阻之间的比例关系,以及真人测试和假人测试服装总热阻之间的关系,利用热流计法对人体设定的10个部位测定热流密度,计算得到服装局部的热阻,通过面积系数计算得到站立和和行走状态的服装总热阻,然后对不同测试条件下各部位服装的动静态热阻进行线性拟合,得到拟合斜率,并探讨 了不同状态对服装热阻的影响。结果显示：动态热阻明显低于静态热阻,10个部位动静态模拟斜率依次为：0.72,0.75,0.87,0.74,0.75,0.83,0.82,0.95,0.61,0.64;斜率小于或等于0.76的部位受运动的影响显著。最后得到真人测试的静态热阻和动态热阻,真人和假人测试得到的静态热阻以及动态热阻之间的数字模型。     

多功能针织窗帘织物的制备及性能研究

采用特里科双面经编机技术,设计了三梳的复合组织,将三叶形截面涤纶长丝和全消光涤纶长丝分别覆盖于织物的两面,得到了双面异构织物。对织物密度、厚度、克质量进行测试,窗帘织物厚度仅为0.4 mm,克质量也仅有120 g/m2,该设计属于薄型织物。采用分光光度计法测试了织物的光学性能,结果显示,所设计织物具有透光、防窥、抗紫外线性能,改善了需多层窗帘搭配使用才能解决的问题。     

基于机器视觉的鸡蛋品质无损检测方法

目的以蛋品质量评价指标—哈夫单位值为检测标准,建立一种基于机器视觉的鸡蛋品质无损检测方法。方法通过摄像头捕捉到鸡蛋图像信息,利用MATLAB对鸡蛋图像的G分量以及I分量进行特征参数提取,并计算出与鸡蛋新鲜度相关的4个特征参数:蛋黄面积比、气室面积比、气室高度比与气室直径比,将其作为自变量,通过高精度游标卡尺实测每个鸡蛋样本哈夫值作为因变量,分别建立一元回归模型,寻找特征参数与哈夫值的关系,并根据哈夫值对鸡蛋新鲜度进行分级。结果实验表明,所测4个特征参数中,蛋黄面积比与哈夫值存在较强的相关性,相关系数为0.78,拟合优度为0.62,蛋黄面积比越小,鸡蛋哈夫值越大,说明鸡蛋越新鲜。结论基于机器视觉的鸡蛋品质无损检测方法不仅具有较强的应用价值,还可以为鸡蛋品质智能分级提供技术支撑。     

Electrical resistance of jute needle-punched non-woven fabric – effect of punch density,needle penetration and area density

The electrical resistance of jute needle-punched non-woven fabric has been studied. Statistical model using central composite rotatable experimental design is developed for electrical resistance depending on the three important parameters of needled non-woven fabric, i.e. punch density, depth of needle penetration and mass per unit area. From this model and its contour diagrams, the effects of different parameters can be understood on electrical resistance of those fabrics. Prediction of electrical resistance can be made knowing the values of independent parameters. The correlation coefficients between observed and predicted values are found to be significant in all the cases. As depth of needle penetration increases for a particular punch density, electrical resistance increases and after reaching to maximum, it decreases having optimum at about 140 punches/cm² and 12?mm depth of needle penetration. With the increase of area density, resistance decreases. As punch density increases for a particular area density, resistance increases for high needle penetration.     

Regression model for predicting the air resistance of fabric made from doubled yarns and with different weave structures

The purpose of the investigation is to model the effect of doubled yarns produced from conventional and compact yarns in three different combinations and weave structures on the air resistance of fabrics. A series of woven fabrics differing only in weave structures and having the common count and fabric sett was produced from three types of doubled yarns, namely compact/compact, conventional/conventional and compact/conventional. The hybrid combination was produced principally to reduce the cost of manufacturing doubled yarns. Essential data for the fabrics such as CFF (crossing over firmness factor), FYF (floating yarn factor), FFF (fabric firmness factor), mass per unit area, thickness and porosity were determined. Air resistance was determined by performing the standard test KES-F8 API. Analysis of the results in respect of fabrics produced from the compact/compact, conventional/conventional and conventional/compact yarns shows a strong correlation between the air resistance, porosity, CFF, FYF, FFF, mass per unit area and thickness (R = conventional/conventional 0.97, compact/compact 0.861, conventional/compact 0.974) and the generated statistical models have given the satisfactory prediction of air resistance. Among the parameters, thickness exerts a strong influence on the air resistance. It is concluded that in order to predict air resistance, a number of parameters are needed and any conclusion which has been drawn using only CFF and FYF should be treated with caution. Also the possibility of cost saving as a result of using hybrid doubled yarn has been pointed out.     

Comparison of the properties of Ring,Solo, and Siro core‐spun yarns

In this research, core‐spun yarns with an acrylic sheath fiber and a nylon flat core have been produced on the Ring, SIRO, and Solo spinning systems and the effects of some factors were investigated. The studied factors consist of filament pre‐tension (i.e. 1, 7/5, 10, 15, 50, and 100 g), spinning system (Ring, SIRO, and Solo), and feed position of the core filament in the strands of sheath fibers (six types of feed positions). Also, their physical and mechanical properties, including strength, elongation percentage, abrasion resistance, percentage of coefficient of variation (CV%), and hairiness, were all investigated. Finally, in each stage, the best case was determined. The results show that the quality of the core‐spun yarns produced by the SIRO spinning system is better than that of the Ring and Solo core‐spun yarns.     

可加热纬编针织物的电热性能

为开发可加热纬编针织服装,采用衬纬方式将导电丝织入针织物中,并对其电热性能进行测试和分析。分别将单根、2根、3根镀银长丝和单根不锈钢长丝衬入到针织物中,测试导电纱线的最大负载电流、织物的热稳定性、织物的电热升温特性和表面温度的均匀性。结果显示:不锈钢长丝的最大负载电流最大,其次是3根镀银长丝的;通电后,衬入镀银长丝织物的电阻变化率较小;衬入3根镀银长丝的织物通电后温度升高的速度较快,且达到稳定工作的温度较高;测试范围内,织物的稳定温升与输入电压成正比;织物表面温度均匀性较好。认为可选择衬入3根镀银长丝的纬编织物制作可加热针织服装。     

竹节纱织物竹节分布均匀性评价方法

针对二值化图像的重心、面积2个指标,利用图像技术对竹节纱织物表面竹节分布的均匀性进行评价。在计算机辅助生成竹节分布图像基础之上,随机生成10 cm×10 cm的竹节分布图,通过考核各图的重心分布位置及各图之间的面积分布变异系数,综合考量竹节纱织物的竹节分布情况。测试结果显示:当竹节密度较低时,减小竹节各个配比之间的长度差异能有效减少竹节不匀的产生。