pH值对壳聚糖/羧甲基壳聚糖水凝胶溶胀行为的影响

利用壳聚糖与羧甲基壳聚糖制备了一系列新型的水凝胶，研究了pH值对水凝胶溶胀度、微观结构和基团结构的影响．结果表明，壳聚糖与羧甲基壳聚糖水凝胶的溶胀行为和微观结构均表现出pH值敏感性，但随着羧基的引入，水凝胶的最低溶胀度从pH7．O移向pH3．O．红外光谱证明，水凝胶的pH敏感行为是由基团结构的变化引起的．     

一类非线性发展方程整体解的存在性、渐近性与解的爆破

研究一类非线性发展方程初边值问题整体弱解的存在性，渐近性和解的爆破问题，证明在关于非线性项的不同条件下，上述初边值问题分别在大初值和小初始能量的情况下存在整体弱解，并且讨论了弱解的渐近性。还证明：在相反的条件下，上述弱解在有限时刻爆破，并且给出了一个实例。     

Synergistically toughening high‐density polyethylene with calcium carbonate and elastomer

The microstructure, impact strength, and rheological properties of blends consisting of high‐density polyethylene (HDPE) and maleated poly (ethylene‐octene) (POEg) and/or calcium carbonate (CaCO₃) were investigated. The improvement of impact strength of HDPE/POEg was limited due to the high miscibility between them. The introduction of CaCO₃ had a negative impact on the toughness of the matrix because of the poor interfacial adhesion. In ternary blends of HDPE/POEg/CaCO₃, an elastomer layer was formed around CaCO₃ particles due to the strong interaction between POEg and CaCO₃, which improves the HDPE‐CaCO₃ interfacial strength and the toughness of the blends. A significant enhancement of dynamic viscosity, storage modulus, and the low‐shear viscosity were observed as the results of the high miscibility of HDPE with POEg and strong interaction between POEg and CaCO₃. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3213–3221, 2005     

Solution of approximate gluon evolution equation for small-x at fixed ‘ρ’

A simple method has been applied to solve the approximate gluon evolution equation for small-x at fixedρ(≡√ln(x ₀/x)/ln[ln(Q ²/Λ²)/ln(Q ₀ ² /Λ²)]. Numerical comparison is made with the predictions from ‘double asymptotic scaling’ and fit. Better agreement is found between our solution and fit nearρ=1. The solution gives approximate double scaling in this region having ‘hard’ pomeron with small contamination.     

Algebra with polynomial commutation relations for the Zeeman effect in the Coulomb-Dirac field

We consider a model of particle motion in the field of an electromagnetic monopole (in the Coulomb-Dirac field) perturbed by homogeneous and inhomogeneous electric fields. After quantum averaging, we obtain an integrable system whose Hamiltonian can be expressed in terms of the generators of an algebra with polynomial commutation relations. We construct the irreducible representations of this algebra and its hypergeometric coherent states. We use these states to represent the eigenfunctions of the original problem in terms of the solutions of the model ordinary differential equation. We also present the asymptotic approximations of the eigenvalues in the leading term of the perturbation theory, where the degeneration of the spectrum is removed completely.Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 142, No. 1, pp. 127–147, January, 2005.     

A fourth-order parabolic equation modeling epitaxial thin film growth

We study the continuum model for epitaxial thin film growth from Phys. D 132 (1999) 520-542, which is known to simulate experimentally observed dynamics very well. We show existence, uniqueness and regularity of solutions in an appropriate function space, and we characterize the existence of nontrivial equilibria in terms of the size of the underlying domain. In an investigation of asymptotical behavior, we give a weak assumption under which the ω-limit set of the dynamical system consists only of steady states. In the one-dimensional setting we can characterize the set of steady states and determine its unique asymptotically stable element. The article closes with some illustrative numerical examples.     

高维空间中一类Ginzburg-Landau型泛函的极小元的渐近分析

在空间H1,pg(Ω,Rn)中讨论如下一类变系数Ginzburg-Landau型泛函Eε(Ω)=∫Ωa(x)p|Δu|p+14εpb(x)(|u|2-β2(x))2dx的极小元列的渐近性质.这里2≤p0,m≤a(x),b(x),β(x)≤M,且a(x),b(x),β(x)是光滑函数.研究了当ε→0时极小元的渐近性态,证明了极小元列在H1,pg(Ω,Rn)中强收敛于某个元素,且得到了该元素所满足的微分方程边值问题.     

Hydrogen‐bonded thermotropic liquid‐crystalline polyester–amides from bis(hydroxy alkamido)aranes: Synthesis and properties

Hydrogen‐bonded aromatic–aliphatic polyester–amides (PEAs) were prepared by solution/melt polycondensation of aromatic–aliphatic amidodiols 1,4‐bis(4‐hydroxybutyramide)benzene (BHBB), 1,4‐bis(5‐hydroxy pentamide)benzene, 1,4‐bis(6‐hydroxyhexamide)benzene, 1,4‐bis(4‐hydroxybutyramidexylene), 1,4‐bis(5‐hydroxypentamidexylene, 1,4‐bis(4‐hydroxybutyramide)benzene, and 1,4‐bis(6‐hydroxyhexamidexylene) with terephthaloyl chloride/dimethyl terephthalate. Aromatic–aliphatic amido diols were prepared by the aminolysis of γ‐butyrolactone, δ‐valerolactone, and ?‐caprolactone with aromatic diamines such as paraphenylene diamine and paraxylene diamine. The monomers and polymers were characterized by chemical analysis (hydroxyl value and elemental analysis), Fourier transform infrared spectroscopy, ¹H NMR, and ¹³C NMR. The thermal‐ and phase‐transition behaviors of the polymers were investigated by differential scanning calorimetry in combination with hot‐stage optical microscopy. Crystallinity of polymers was examined with wide‐angle X‐ray diffraction. The polymers exhibited liquid crystallinity with layered structures formed by self‐organization of the hetero intermolecular hydrogen‐bonded networks indicating smectic phases except for PEAs prepared from BHBB. The hydrogen atom of the phenyl‐substituent group forces the neighboring carbonyl groups out of plane of the rings preventing formation of layered structures in the case of BHBB. The PEAs retained intermolecular hydrogen bonding even in the mesomorphic state, and variations in the hydrogen‐bonded lamellae/micelles might be responsible for the variations from one smectic to another texture. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 335–346, 2003     

区间数的标准表示及其四则运算法则与泛灰数的内在联系

在回顾泛灰数四则运算法则基础上,给出了区间数的标准表示,论述了标准区间数的四则运算法则与泛灰数的内在联系及其应用前景.     

Effect of pyridazine structure on thin‐film polymerization and phase behavior of thermotropic liquid crystalline copolyesters

An intensive study has been conducted to compare the effects of malei hydrazine (MH) and hydroquinone (HQ) on the liquid crystallinity and phase transition behavior in the ABA/HQ/TFTA and ABA/MH/TFTA copolyesters (p‐acetoxybenzoic acid (ABA) and tetrafluoroterephthalic acid (TFTA)). These two copolyesters were prepared by thin‐film polymerization and characterized by differential scanning calorimetry (DSC), polarizing light microscope (PLM), wide‐angle X‐ray diffraction (WAXD), as well as Cerius² computational simulation. Characterization and comparison of the liquid crystalline (LC) evolution and morphology changes of HQ moiety with corresponding MH moiety suggest that ABA/MH/TFTA system is energetically favorable to mesophase formation than ABA/HQ/TFTA system. When the films are quenched, a surface microcrack decoration is observed in both systems. Both systems, which have the persistence ratio larger than 6.42, satisfy the minimum requirement for the LC formation by molecular science software. The ABA/MH/TFTA film exhibits only one single peak transition. However, two distinct transitions have been observed in the ABA/HQ/TFTA system. The average Avrami exponent, n, is ～1.2, and PLM and WAXD results suggest mesophase transition in ABA/MH/TFTA film. As reflected by the results obtained from PLM, WAXD, and DSC studies, the phase transition is confirmed as crystal → nematic → isotropic in ABA/HQ/TFTA copolyester. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2230–2242, 2005