Isolation and Properties of Melanin in Fine Yak Hair

Melanin granules were isolated from fine yak hair by means of protein enzyme and hydrochloric acid.Resultsof SEM investigation and amino acid analysis were usedto study the physical and chemical properties of melaningranules.The solubility of melanin granules in differentchemical solutions was also studied.     

Global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback

This paper presents both analytical and numerical studies on the global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback. Based on a detailed analysis of the stability switches of the trivial equilibrium of the system, the stability charts are given in a parameter space consisting of the time delay and the feedback gains. The center manifold reduction and the normal form method are used to study Hopf bifurcations with respect to the time delay. To gain an insight into the pe...     

Structure Characterization of Silk Fibroin Crystalline Domain Polypeptides Expressed in Escherichia coli

The molecular conformations of four silk fibroin crystalline analogues [GAGAG-X] 16(G,Gly;A,Ala;X=Ala,Ser,Tyr or Val,designated eGA,eGS,eGY or eGV),carried out using molecular design and expressed by Escherichia coil(E.coli),were evaluated by Raman spectra analysis.The abilities of forming β-sheet structure were determined by thioflavin T(ThT) fluorescence spectra analysis.In terms of molecular conformation,except eGY that could not form significant typical molecular conformation,eGS and eGV were mainly com...     

In-plane elastic stability of fixed parabolic shallow arches

The nonlinear behavior of fixed parabolic shallow arches subjected to a vertical uniform load is investigated to evaluate the in-plane buckling load.The virtual work principle method is used to establish the non-linear equilibrium and buckling equations.Analytical solutions for the non-linear in-plane symmetric snap-through and antisymmetric bifurcation buckling loads are obtained.Based on the least square method,an approximation for the symmetric buckling load of fixed parabolic arch is proposed to simplif...     

一个时滞经济增长模型的动态分析

提出了一个基于Solow模型的考虑时滞作用的多种资本投入的经济增长模型，该模型的生产函数是满足“新古典”条件的一次齐次函数，在所的条件下，证明了系统有唯一的正平衡解；使用单调互动力系统的已有结果推得系统的正解是全局稳定的，关于参数的静态分析也与经典的增长模型完全一致，结果表明，在考虑时滞与多资本的因素下，经济系统仍能达到稳定状态，这在一定意义上揭示了Solow模型的深刻内涵。     

关于Hardy不等式在一个区间上的改进

用权系数的方法，对ｐ∈「７／６，２」，１／ｐ＋１／ｑ＝１，建立Ｈａｒｄｙ不等式的一个加强式：∑ｎ＝１＾∞（１／ｎ∑ｋ＝１＾ｎａｋ）＾ｐ〈ｑ＾ｐ∑＾ｎ＝１＾∞（１－１５／１９６．１／ｎ＾１／ｑ＋３４３６）ａｎ＾ｐ。     

增益钳制半导体光放大器的实验研究

为了提高半导体光放大器（SOA）的3dB饱和输出功率和稳定增益，用外腔反馈的方法在普通半导体光放大器的增益谱边缘引入一个钳制激光振荡，研制了增益钳制半导体光放大器（GC－SOA），对其阈值特性，增益特性及开关特性进行了实验研究，结果表明，通过在SOA的增益谱边缘引入钳制激光，稳定了SOA的增益，使SOA的饱和输出功率提高了4dB.     

速滑运动员腰肌劳损的预防措施

腰肌劳损是速滑运动员的多发病 ,本文在调查的基础上 ,提出了预防及医疗等措施 ,对速滑等项目的运动训练 ,提出了改进建议。     

感知机网络模型

文章提出了一种利用人工神经元网络方法-感知机网络实现设计并训练一个印刷字符分类器，程序采用MATLAB5.3实现。     

PON突发式光接收模块的指标及其测试系统

基于ＴＤＭＡ 的无源光纤接入网（ＰＯＮ），具体分析了其关键部件——突发模式光接收模块的性能特点，提出了描述该模块的几项重要指标，设计制作了一具体的指标测量系统并说明了测量步骤．