粗纱假捻器的实践与分析

本文通过对假捻器的选型设计、测试等实践及理论分析,对引进设备上的几种假捻器进行了消化性研究.由测试结果可以看出,假捻器的假捻效果主要反映在纺纱段.假捻器使纺纱段捻度提高,有利于改善粗纱伸长率、粗纱前后排伸长率的差异以及一落纱中伸长率的差异.通过本文理论分析有如下结论:1.假捻器设计参数合理,可使纺纱段捻度明显提高;2.提高纺纱段的假捻效果,可以降低粗纱伸长率及伸长率差异;3.要提高假捻器的假捻效果,可以通过采用摩擦系数较大的材料,适当增加假捻器的内径和外径,以及选择合适的摩擦接触角与齿形.     

转杯纺加工兔棉纱混纺比、假捻盘、捻系数的优化研究

本文对转杯纺加工兔棉混纺针织纱,选取兔棉混纺比、捻盘直径、成纱捻系数等三因子,进行优化设计与纺纱试验.根据试验数据,通过运算,建立试验因子与确定成纱质量指标间的回归方程。再通过计算机对各回归方程绘制两维等高线图,从图可以看出,兔棉混纺比、假捻盘直径、捻系数对成纱质量均有显著影响、同时,对试验所得数据,进行优化处理,建立数学模型,并通过计算机运算求解,结果得出:在转杯低速(35200r/min)时,纺62.5tex混纺纱,最佳工艺参数为捻系数394～399;假捻盘直径25～27mm,兔/棉混比35/65～45/55.     

静电纺纱加捻效率的初步研究

本文对静电纺纱的加捻机理和加捻效率进行了分析。通过实验测得了加捻管的机械加捻撩效率,从而得出了影响纱线捻度和加捻效率的主要因素。并采用二次回归通用旋转组合设计方法建立成纱捻度与加捻效率的回归方程。通过理论分析和实验结果所得结论是:在自由端须条上的假捻是影响加捻效率的主要因素,而机械滑溜相对来说比较小。影响纱线捻度和加捻效率的主要工艺参数是加捻管的转速和引纱速度。这两速度越高,总的加捻效率越低。     

减羽喷嘴中纱线运动状态研究

分析了喷嘴内纱线运动状态、受力、旋转速度等,探讨减少纱线毛羽的机理及减羽的可行性,得出纱线旋转速度与纱线直径、纱线气圈速度、解捻过程、喷嘴结构参数的关系.同时分析了"假捻-解捻-包缠"减少毛羽的机理.纱线毛羽在气流的作用下被包缠在纱体周围.通过计算特定条件下纱线通过喷嘴的时间,及毛羽包缠纱体的时间,并比较得出毛羽可以包缠在纱体周围.     

麻赛尔/棉转杯纺纱工艺研究

以捻系数、分梳辊速度、转杯速度为试验因子,采用单因子实验和二次通用旋转组合设计法,研究麻赛尔/棉混纺纱线性能与工艺参数之间的关系,找出最佳工艺参数;并用最佳工艺参数纺制不同混纺比的麻赛尔/棉混纺纱,比较不同混纺比对纱线性能的影响.结果表明：随着捻系数、分梳辊速度、转杯速度的增加,成纱的断裂强力均呈现出先增加后下降的变化规律;随着麻赛尔纤维含量的增加,混纺纱线的断裂强力逐渐下降.     

棉/涤纶长丝Sirofil复合纱成纱工艺性能研究

以低弹涤纶长丝和精梳纯棉粗纱为原料,纺制不同捻度、不同喂入间距、不同长丝预张力的Sirofil复合纱,并测试了纱线的强力、条干和毛羽.通过正交试验分析方法,得到实验范围内棉/涤纶长丝Sirofil复合纱的优化纺纱工艺参数为捻系数321,长丝须条间距6mm,长丝张力片重量3g.     

转杯纺纱阻捻器阻捻系数理论分析

通过分析阻捻器阻捻机理，建立了可衡量转杯纺纱阻捻器阻捻效果大小的任意曲面阻捻器阻捻系数的理论模型，并对圆柱面阻捻器阻捻系数进行了数值计算，得出纺纱工艺参数以及安装参数对阻捻系数大小均有一定影响的结论。     

响应曲面法在柴油机配气相位优化中的应用

使用AVL-BOOST建立某186F柴油机的计算模型,通过计算模型产生响应曲面设计试验点的数据.采用中心复合设计将得到的响应数据建立响应曲面模型,并对响应模型进行方差分析及回归系数显著性检验,确保所建立的三元二次模型的可信度.由响应模型绘制等值线图、响应曲面图.使用Minitab响应优化器求解标定转速处最优的配气相位,并采用优化后的配气凸轮进行柴油机试验验证.结果表明:进气迟闭角对该柴油机标定点的比油耗影响最为明显,排气提前角次之,适当增大进气迟闭角、排气提前角和气门重叠角可以提高柴油机高转速区的充量系数和经济性;当转速超过2 800 r·min~(-1)时,充量系数和比油耗较原机均有不同程度的增大与减小,其中标定点处的比油耗降低了2.12%,充量系数增大了4.88%.     

毛涤粘混纺纱线微波定捻工艺的优化

用微波对4种不同细度的毛涤粘混纺纱线进行定捻,研究微波快速定捻毛涤粘混纺纱线的可行性及其定捻工艺．分析影响毛涤粘混纺纱线微波定捻效果的因素,并通过正交试验优化微波定捻工艺：微波功率1000W ,作用时间3min ,回潮率控制在9.2％左右．实验表明,经微波定捻后的纱线较传统蒸纱定捻后的纱线断裂强度有所提高,断裂伸长率有所增加,纱线的强力不匀率有所下降,纱线的定捻率有所提高,能满足生产要求．     

用EIB对变形纱线直径变化特征的测试

为了对变形纱外观形态特征进行更好的评价,利用EIB对线密度接近（16tex左右）的棉纱、毛纱、加捻长丝、空气变形纱和假捻变形纱分别进行测试,对获得的纱线直径、纱线片段不匀（CV）、直径粗细分布、纱线模拟形态图等参数和指标进行分析,并在此基础上对实验纱线直径变化情况进行比较和评价.通过实验定量地说明线密度为16tex左右的变形纱纱线直径粗细变化类似于短纤棉毛纱,并且得出利用EIB来比较和评价纱线直径粗细变化特征的方法是有效的.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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