倾斜板料总裁矩形孔的冲裁力研究

倾斜板料冲裁的冲裁力计算是一个尚待研究的问题，本文对倾斜板料矩形冲裁的冲裁过程中进行了探讨，将其分为板料包容冲头和板料不包容冲头两种类型和三个冲裁阶段，推导了每种类型各冲裁阶段冲裁力的理论计算公式，分析了冲裁力随行程的变化规律，研究了最大冲裁力和板料厚度，矩表孔尺寸板料倾斜角度等的关系，获得了一些对设计有参考价值的结论。     

基于直线电机驱动的四级正交增力装置

介绍了1种新型的基于直线电机驱动的四级正交增力装置,对系统的工作原理进行了分析,并给出了工作原理图。文章对系统的输出力和力放大系数给出了相应的计算公式。该装置以直线电机为动力源,结合偏心轮与铰杆机构进行输出力的放大。该装置技术功能较为完善,能对输入力进行高倍放大后输出,是对复合传动绿色化设计的1种尝试。     

基于直线电机驱动的新型二级增力夹具

介绍了一种新型的基于直线电机驱动的二级增力夹具,对系统的工作原理进行了分析.并给出了工作原理图.对系统的输出力及其力放大系数给出了相应的计算公式.该装置以直线电机为动力源,利用铰杆之间的角度效应进行输出力的放大.该装置技术功能较为完善,能对输入力进行高倍放大后输出,是对复合传动绿色化设计的一种尝试.     

导丝热辊的新进展

正过去两年中瑞士Retech公司致力于导丝热辊产品及其标准化业务。Retech公司的导丝热辊变体数量降低到3种主要型号。基于节能电机(ESM)和永磁同步磁技术概念,根据应用和加工,目前主要的3种电机型号分为不同能效等级。相对这些电机有不同的转辊尺寸(Φ100 mm+127 mm用小型电机,Φ160 mm用中型电机,     

基于三级增力机构的直线电机压紧装置

设计了一种新型的基于三级增力机构的直线电机压紧装置,分析了系统的工作原理。给出了工作原理图．并给出了系统的力学计算及其力的放大系数计算相应的计算公式。该装置以直线电机为动力源,利用铰杆间的角度效应进行输出力的放大。装置的技术功能较完善,能对输入力进行高倍放大后输出,是复合传动绿色化设计的一种尝试。     

直线电机驱动的二级增力压紧装置

介绍了1种新型的基于直线电机驱动的二级增力压紧装置,对系统的工作原理进行了分析,并给出了工作原理图.文章对系统的力学计算及其力放大系数给出了相应的计算公式.该装置以直线电机为动力源.利用铰杆与斜楔的角度效应进行输出力的放大.该装置技术功能较为完善,能对输入力进行高倍放大后输出,是对复合传动绿色化设计的尝试.     

高温超导同步发电机的励磁绕组优化

本文主要研究高温超导电机的磁密,分析了影响超导电机磁密因素,并获得最佳磁密。     

复卷机放纸辊直流电机额定功率的选择

通过对放纸辊电机运行特点的分析,说明在选择电机额定功率时,关键是计算电机的最大负载电流。文中分析了最大负载电流发生的所有可能情况,并给出了计算方法和步骤。     

高温超导同步发电机的励磁绕组优化

本文主要研究高温超导电机的磁密，分析了影响超导电机磁密因素，并获得最佳磁密。     

一种机车用电机悬挂座的结构质量改进

根据某机车用电机悬挂座的受力情况和运营工况条件,采用有限元仿真分析软件对其进行了受力、变形量、外型结构分析及计算,得出电机悬挂座外型结构与受力、变形之间的关系,进而对其结构提出了可行性改进方案。结果表明,经过改进后的电机悬挂座能有效降低最大应力及变形量,是一个合理的结构质量改进。     

纺织基伤口清创材料的纤维抽拔力研究

为研究纺织基伤口清创材料的结构参数与纤维抽拔力的关系,选择6种不同绒密和底布纱线股数的试样。采用拆解法测定每种试样的单位质量、含绒量和底布质量;采用图像处理技术测定每种试样底布的未充满系数和孔隙率;测试每种试样的纤维抽拔力。结果表明:纺织基伤口清创材料的纤维抽拔力与绒密、底布纱线股数都有一定的相关性。底布纱线股数相同时,绒密越高则纤维抽拔力越大;绒密相同时,底布纱线股数越多则纤维抽拔力越大。     

Charge density alterations in human hair fibers: an investigation using electrostatic force microscopy

A new method for high-resolution analyses of hair surface charge density under ambient conditions is presented in this paper. Electrostatic force microscopy (EFM) is used here to analyze changes in surface charge density in virgin hair, bleached hair, and hair treated with a cationic polymer. The atomic force microscopy technique is used concomitantly to analyze morphological changes in hair roughness and thickness. The EFM images depict exactly how the polymer is distributed on the surface of the hair fiber. The EFM's powerful analytical tools enabled us to evaluate the varying degrees of interaction between the hair fiber surface charge density and the cationic polymer. The surface charge density and the polymer's distribution in the hair fibers are presented in the light of EFM measurements.     

SPECIFIC GRAVITY DETERMINATION WITH A UNIVERSAL TESTING MACHINE

SUMMARY —A rapid, precise technique for determining specific gravity of fruits and vegetables was developed. The method utilized a universal testing machine. The effects of crosshead speed, choice of standard density fluid and weight measurements were studied and optimized. A standard sphere of known volume and weight was used to compare this method with other techniques now used. In addition to using the standard sphere, tomatoes were studied to evaluate the efficiency of this method. Calculation of specific gravity involved determining fruit volume and weight. Other volume measurement techniques investigated proved inaccurate or too time-consuming. An Instron universal testing machine was used in measuring the buoyancy force of a fruit submerged in a standard density fluid. The buoyancy force is directly related to the fruit volume. Error analysis showed relatively low sensitivity to errors in weight measurement, but was influenced mainly by errors in determining the fluid density. This error was minimized by use of high-density fluids; thus, saturated salt brines and high-density organic fluids were used for the experimental work.     

The use of gray scale images when evaluating disturbances in cutting force due to changes in wood structure and tool shape

A method is presented for studying the effect of momentary disturbances due to variations in wood structure on the cutting force near the cutting edge. Force and density measurements are converted to a gray scale image. This method is very effective as regards the evaluation of experimental tests.     

Moisture-dependent properties of barnyard millet grain and kernel

The geometric mean diameter, sphericity, grain surface area, 1000 grain mass, true density (toluene displacement method), terminal velocity, dynamic angle of repose, coefficient of internal friction, coefficient of static friction at different surfaces (sun mica, canvas and mild steel surfaces), specific deformation and rupture energy of the grain were found to increase 12.21%, 4.79%, 30.47%, 30.75%, 6.74%, 32.99%, 127.05%, 60%, 18.57%, 34–67%, 69.2% and 88.87% respectively at increase of moisture content from 0.065 to 0.265 kg kg⁻¹ dry matter. However, true density (proximate composition method), bulk density, interstices and rupture force of grain was found to be decrease 8.64%, 20.1%, 86.49% and 21.17% respectively at increase of moisture content. Similar trend was observed for barnyard kernel also. True density (toluene displacement method) was found lower as compared to true density (proximate composition method) at all experimental moisture range indicated that the presence of void space inside the grain and kernel.     

厚空间结构板热压过程中纤维流动状态的分析研究

厚空间结构板是一种应用前景非常广泛的模压制品，但因制造工艺复杂，目前尚处于研究阶段。在研究过程中发现，厚空间结构板在热压时板坯内部会产生应力流层，使纤维从栅壁部分自动流向面板部分，加大了栅壁部分与面板部分的密度差异。     

羽绒纤维各项性能测定方法的探讨

介绍了羽绒纤维 12个重要指标 ,即耗氧指数、弹性、残脂率、含水率、断裂弹力和断裂伸长、膨润性、摩擦系数、热收缩性、润湿收缩性、电性、导热性、比重的测试方法     

Quality grading of cork stoppers based on porosity,density and elasticity

An objective control method for grading cork stoppers is presented using a cork stopper quality index based on porosity, density and elasticity, these being the properties which have the greatest influence on the closure capacity of the stopper. The elasticity of the cork stopper is measured through the relaxation ratio, which is defined by the relationship between the relaxation force exerted by the cork in the bottleneck and the compressive force exerted by a caliper to fit the stopper in the bottle. The relaxation ratio, defined in this way, represents the part of the compression force which is applied to the stopper on insertion and which is recovered in the form of the relaxation force to achieve closure. The calculation of the relaxation ratio involves the measurement of the relaxation force of the fitted stopper. This force has been measured rigorously and precisely using a device developed in the Cork Laboratory at the INIA-CIFOR and which is presented for the first time in this paper.     

MICROSTRUCTURAL CHARACTERISTICS AND COMPRESSION RESISTANCE AS INDICES OF SENSORY TEXTURE IN A CRUNCHY SNACK PRODUCT

Identically formulated drum dried and cold formed half-products were puffed in hot air or by frying to determine microstructure-texture relationships. Structural attributes measured were cell size (CS), number of cells per unit area (CN), cell wall thickness (CW) and product specific volume (SV). Sensory attributes of crunchiness, hardness and density were also evaluated. Puffed product microstructure depended more on the half-product preparation process than the method of puffing. Similarly prepared half products had the same microstructural attributes whether fried or hot air puffed. Sensory scores for crunchiness were not significantly different among all samples but scores for hardness and density were significantly different between hot air puffed and fried products even when microstructural attributes were similar. Higher compression force values reflected lower sensory scores for crunchiness and hardness of puffed products. Compression force was significantly correlated with microstructural attributes of CS, CW and SV.     

基于纤维长度分布的浮游纤维变速仿真

采用非参数核密度估计的方法获得纤维长度分布的密度函数,随机生成牵伸区纤维分布样本。利用多项式回归拟合出JF型双短胶圈环锭细纱牵伸装置的纵向摩擦力界分布函数,结合纤维变速的数学模型,采用计算机方法模拟出JF型牵伸装置在纤维等长均匀分布和核密度估计分布下的变速点分布形态的直方图。结果表明：等长分布纤维的变速点高度集中于前钳口;核密度估计分布纤维变速点分度离散,近似于正态分布,表明纤维尾端离开后钳口即会有变速可能,可见核密度估计分布下纤维变速点分布的模拟结果更接近于真实情况。此方法可用于对实际牵伸工艺和牵伸机构的优化和预测。