干热处理对苎麻纤维结构和性能的影响

本文讨论了苎麻纤维分别在120℃、130℃、140℃和150℃干热处理下其结晶度与取向度的变化、强力与伸长的下降以及染色性能的改善。本文采用KES-FB-2纯弯曲试验仪测试了苎麻纤维的柔软性。用弯曲刚度及弯曲滞后矩表述试样的柔软性,对两者进行了比较。经干热处理后苎麻的柔软性亦有所提高。     

凉爽羊毛/苎麻复合纱的前处理工艺研究

介绍了羊毛与苎麻两种粗纱的前处理工艺。实验证明，高锰酸钾一蛋白酶改性处理后的羊毛纤维能够去除羊毛的鳞片以消除其对人体的刺痒感，并且保持羊毛的强伸性能不发生明显改变。而碱一纤维素酶改性处理后的苎麻纤维不仅对伸长率、结晶度、取向度与刚度等各方面性能都有较大改善，而且对其后道成纱工艺及服用性能也有一定作用，为夏季用羊毛，苎麻复合纱的开发奠定基础。     

不同脱墨方式对二次纤维孔隙结构和结晶性能的影响

采用X射线衍射和等温氮吸附法研究了废旧新闻纸(ONP)在不同脱墨方式下孔隙结构和结晶性能的变化,并运用分形理论对纤维的孔隙结构进行了分析.等温氮吸附实验发现,ONP浆经过中性、碱法和酶法脱墨后,其BET比表面积、BJH孔容及BJH平均孔径变化不大.分形分析发现,脱墨前后纤维的分形维数相近,说明三种脱墨方式对纤维的孔隙结构影响较小. X射线衍射实验发现ONP浆经过中性、碱法和酶法脱墨后,结晶度下降,碱法脱墨浆纤维结晶度下降最大,达12.24%,中性脱墨浆下降6.12%,酶法脱墨浆下降最少仅0.77%.研究中还发现,经过脱墨后,纤维的保水值有所增大,其中碱法脱墨浆纤维增加最大,中性脱墨浆次之,酶法脱墨浆最小.     

脱墨方式对二次纤维孔隙结构和结晶性能的影响

通过X射线衍射分析和低温氮吸附法等方法研究了废旧新闻纸(ONP)浆及经不同脱墨方式脱墨后的脱墨浆的纤维孔隙结构和结晶性能的变化,并运用分形理论对纤维的孔隙结构进行了分析.结果表明:ONP浆经过中性、碱法和酶法脱墨后,其BET比表面积、BJH孔容及BJH平均孔径变化不大;脱墨前后纤维的分形维数相近,脱墨方式对纤维的孔隙结构影响较小;ONP浆经过中性、碱法和酶法脱墨后,结晶度下降,碱法脱墨浆纤维结晶度下降12.24%,中性脱墨浆下降6.12%,酶法脱墨浆下降最少,仅0.77%;经过脱墨后,纤维的保水值有所增大,其中碱法脱墨浆纤维增加最大,中性脱墨浆次之,酶法脱墨浆最小;脱墨后纤维打浆度和平均长度下降较小,细小纤维含量增加.     

纺丝速度对Lyocell纤维结构的影响

研究了以N 甲基吗啉 N 氧化物(NMMO)为溶剂的Lyocell纤维纺丝工艺中纺丝速度对Lyocell纤维结构的影响.实验结果表明:随着纺丝速度的提高,Lyocell纤维的结晶度、晶区取向、双折射及无定形取向增大,但当纺丝速度达到50m/min时,纤维的双折射和无定形取向都达到最大值,纺丝速度继续提高,纤维的双折射维持恒定不变,无定形取向反而下降.     

热处理对Lyocell纤维结构和性能的影响

研究了热处理时不同的温度、时间及张力对Lyocell纤维结构和性能的影响。结果表明热处理能提高Lyocell纤维的强度和模量，但是断裂伸长率有所下降。热处理温度为160℃，时间为12～25s时效果较好。热处理中施加张力可以进一步提高Lyocell纤维的强度和模量，但纤维的断裂伸长率迅速下降。热处理后的Lyocell纤维结晶度略有提高，但随着张力的增加，结晶度基本不变。热处理后纤维的总取向增大，而晶区取向基本不变，故无定形区取向大幅度提高。研究结果还表明Lyocell纤维通过热处理而提高的力学性能并不能长久地维持，随着放置时间的延长，其力学性能会逐渐下降并回复到热处理以前的状态。     

N,N-二甲基乙酰胺对苎麻纤维处理的研究

为降低苎麻纤维结晶度,改善其柔软性能,采用N,N-二甲基乙酰胺(DMAc)对苎麻精干麻进行溶胀降晶处理,并研究了处理工艺对苎麻纤维的力学性能与柔软性能的影响.结果表明:随着DMAc质量分数的增加、处理时间的延长和处理温度的升高,苎麻纤维的断裂强度呈下降趋势,断裂伸长率和断裂回转数呈增大趋势,纤维变得柔软;DMAc质量分数为20%、处理时间为2h、温度为80℃为较佳工艺;较佳工艺下处理的苎麻纤维表面粗糙且有裂痕,纤维结晶度由80.73%降至70.36%;NaOH预处理可提高DMAc对苎麻纤维的处理效果,但NaOH质量分数宜控制在5%以内.     

碱处理对亚麻纤维性能的影响

通过改变碱液浓度、浸碱时间和浴比，采用L9（3^3）正交实验对亚麻纤维进行碱处理工艺优化，研究碱处理对亚麻纤维性能的影响．实验结果表明，经碱液处理后，亚麻纤维的主体纤维比例增大，伸长性提高，并产生大量卷曲，但平均长度减小、强度下降．其中碱液浓度是影响亚麻纤维性能的最显著因素．     

粘胶纤维在甘油中松弛热处理时微细结构的变化及其对性能影响的研究

将粘胶纤维于不同温度下在甘油中松驰热处理后,用计算机分峰法研究其微细结构的变化及其对性能的影响。已发现,在松驰状态下,在190℃以上温度热处理时,发生结晶度的增加和晶型的转变。结晶度的增加主要是纤维素Ⅳ的增加,而纤维素Ⅳ的形成包括由无定形区大分子结晶和由纤维素Ⅱ转化两个过程。由纤维素Ⅱ明显地向纤维素Ⅵ转化的温度在230℃左右,并且发现这个转化温度随热处理的时间及张力而变化。经低温稀碱处理后,发现部分纤维素Ⅳ又会转变成纤维素Ⅱ。在190℃以下(包括190℃)热处理纤维的结构参数变化不大,但它的大部分性能变好。热处理温度高于190℃以上时,由于聚合度下降引起纤维强度降低。同时,实验得出纤维素Ⅳ的含量增加,有使纤维湿模量增大,而膨润度、吸湿率下降的趋势。这对改善粘胶纤维的性能有重要的作用。     

改善苎麻及其混纺纱弹性研究

本文主要为了改善苎麻纱和麻棉纱的弹性,对苎麻纱、麻棉纱和棉纱进行了碱处理。并根据前人所做的工作,即有张力状态下碱处理和松弛状态下碱处理,其纱线性能存在较大差异,因而本文着重考虑在不同张力状态下进行碱处理,研究结果表明,采用低张力进行碱处理。其苎麻纱和麻棉纱的最大变形能力即断裂伸长显著增加,初始弹性模量显著下降,纱线变形恢复能力显著提高。     

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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