在重力场和磁场影响下自旋刚性航天器的周期运动

考虑重力场和磁场对轴对称航天器本体的影响，研究其质心在圆形轨道上的运动,通过降低系统的运动方程数，并将它变成为一个带电粒子在电磁场作用下的平面运动．确认系统运动是稳定的，并通过Liapunov全纯积分定理，构建其近似的周期运动.     

Matrix Lax Polynomials, Geometry of Prym Varieties and Systems of Hess–Appel’rot Type

We consider a four-dimensional generalization of Hess–Appel’rot system and costruct its Lax pair. Both classical and algebro-geometric integration procedure are proceeded. The algebro-geometric integration is based on deep facts from geometry of Prym varieties such as the Mumford relation and Mumford-Dalalyan theory. The integration is similar to the integration of Lagrange bitop which has recetly been performed by the authors.     

Wellposedness for the Navier–Stokes flow in the exterior of a rotating obstacle

In this paper we study the Navier–Stokes boundary‐initial value problem in the exterior of a rotating obstacle, in two and three spatial dimensions. We prove the local in time existence and uniqueness of strong solutions. Moreover, we show that the solutions are global in time, in two spatial dimensions. Copyright © 2005 John Wiley & Sons, Ltd.     

Study of the Crystallization of an Aromatic Poly-ether-ketone (PK99) by Calorimetric and X-ray Analysis

An analysis of the crystallization behaviour of a new poly(aryl-ether-ether-ketone-ketone), PK99, by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) is presented. Isothermal crystallization TG were obtained in the whole range between the glass transition temperature (T _g) and the melting temperature (T _m) as a consequence of the slow crystallization kinetics stemming from the closeness of these transitions. The calorimetric results, compared with WAXD data, were applied to determine the theoretical melting temperature and crystallization enthalpy. The DSC and WAXD data were combined in order to calculate the total amount of the crystallizable fraction of the polymer, and a model was proposed to explain the difference between the fractions of crystallinity observed with these techniques. The thermal and X-ray data were also correlated with different lamellar morphologies arising from the crystallization conditions. Finally, DSC experiments on the crystallized sample were used to detect the presence of a rigid amorphous phase which does not relax at T _g. This revised version was published online in July 2006 with corrections to the Cover Date.     

含两种不同介晶基团的半刚性共聚酯液晶态的结构研究

用Ｘ－光衍射，偏光显微镜及ＤＳＣ对含两种不同长度介晶基团４，４’－联苯二酚（Ⅰ）和对苯二甲酸二（对羟苯基）酯（Ⅱ）的系列共聚酯的液晶态进行了表征，据其液晶态中两种介晶单元的堆砌方式提出了可能的模型，这种模型很好地解释了液晶态的Ｘ－光衍射分布．     

Trigonal-planare CuX3-Gruppen in Cu2Mo6X14, X = Cl,Br, I

Trigonal Planar CuX₃-Groups in Cu₂Mo₆X₁₄, X = Cl, Br, I Cu₂Mo₆Cl₁₄ (I), Cu₂Mo₆Br₁₄ (II) and Cu₂Mo₆I₁₄ (III) were synthesized by thermal treatment of corresponding mixtures of copper(I) and molybdenum(II) halides. The crystal structures were determined by single crystal X-ray analyses. I and II show isotypism, cubic, Pn3 (no. 201, sec. setting), Z = 4, I: a = 12.772(3) Å, II: a = 13.350(2) Å. III shows a new structural type, orthorhombic, Pbca (No. 61), Z = 4, a = 16.058(3) Å, b = 10.643(2) Å, c = 16.963(3) Å. Trigonal planar CuX₃ units were found in I? III. Structural behaviour relations are discussed, especially with regard to ionic conductivity.     

Pattern of separatrices and intrinsic reaction coordinates for degenerate thermal rearrangements

A structurally stable model of the standard adiabatic gradient field of the potential energy surface for certain pericyclic reactions is derived.These reactions are not subjected to the principles of orbital isomerism or to the Woodward-Hoffmann rules.Use is made of a principle established by Ariel Fernández and Oktay Sinanolu which precludes direct meta-IRC connections between transition states.It is shown that Jahn-Teller isomers of the singlet biradicals involved in the process are not interconvertible since the biradical configuration is not a transition state but a critical point with Hessian matrix with two negative eigenvalues.The topological features of the PES obtained by combinatorial methods are in full agreement with earlier results obtained from MINDO calculations.     

Planar potentiometric sensors based on Au and Ag microelectrodes and conducting polymers for flow-cell analysis

Back-side contact Au and Ag microelectrodes were used as transducers to construct planar all-solid-state electrodes suitable for flow-through analysis. The microsensors were based on plasticized PVC potassium-selective membranes containing ion-electron conducting polymer—polypyrrole doped with di(2-ethylhexyl) sulfosuccinate. The proposed technique allowed simple construction of microsensors in one step, by membrane solution casting directly on the surface of the planar metallic transducers. The performance of the microsensors based on Au and Ag transducers were determined and compared with planar sensors based on internal electrolyte immobilized in polyHEMA. The addition of the polypyrrole to the membrane composition did not influence on the selectivity, reproducibility and long-term stability of the microsensors but improved their standard potential stability in time in comparison with coated-wire type sensors. Moreover, all-solid-state microsensors based on Au transducers exhibited better signal stability than Ag based sensors.     

Rigid aromatic fractal polyamides

The preparation of rigid aromatic, highly branched polyamides is described. Owing to the method of preparation and the chosen ratio of difunctional to trifunctional monomers, these entities are highly porous and not dendrimeric in nature. They better conform with the fractal model and are therefore called fractal polyamides (FPs). The effects of variations in the polymerization procedure, in total monomer concentration, in the ratio of amine to carboxyl groups and in the duration of the polycondensation reaction are investigated. Some characterization was performed and the results are presented and briefly discussed.