(2+1)维mKdV方程dromions相互作用的研究

从两个线孤子解出发，可以得到双线性形式2 1维mKdV方程的某个势函数的dromion解。该dromion解在所有方向都是局域的。两个dromion之间的相互作用通过图形分析的方法进行了详细研究。依据参数的不同选择，该相互作用可以是弹性的也可以是非弹性的。     

具有(G,SV)型休假GI/G/1系统的弱极限

对（G,SV）型休假GI/G/1重话务排队系统进行了分析研究,得到了主要的几个排队论指标的弱收敛极限,使特殊排队系统的弱收敛理论得到了进一步完善。     

伪欧氏空间中类空子流形的第一特征值

利用浸入在伪欧氏空间中类空子流形的Ricci曲率的下界估计,以及Laplace算子第一特征值和浸入的第二基本形式的长度半方相关的性质,建立了紧致类空子流形等距同构于球面的一个特征。     

The Energy Gap in the (Hg1−x Sn x )Ba2Ca2Cu3O8+y Superconductor

The experimental data show that the increase of tin in the (Hg_1?x Sn _x )Ba₂Ca₂Cu₃O_8+y superconductor results in a visible increase in the pseudogap temperature (T ^?) with a slight decrease in the value of the critical temperature (T _C). Based on the above results, the dependence of the average amplitude of the energy gap on the temperature (G(T)) has been determined for x∈〈0,0.25〉. On this basis, it has been found that the dimensionless ratio R _G ≡G(0)/k _B T _C increases with the increasing tin content from the value of 3.48 to the value of 4.88. Next, for x=0.25 and T∈〈0,T ^?〉, the dependence of the energy gap on the wave vector has been calculated in the surrounding of the Fermi level. It has been shown that in the anti-nodal region the energy gap is very weakly dependent on the temperature. On the other hand, in the nodal region its values strongly decrease together with the increasing temperature.     

Photoelectron spectroscopy on metal-polymer interfaces: Ag/polybutene (Ag/PB-1) and epitaxial Sn/polybutene (Sn/PB-1)

The interaction of metals with polymer surfaces is studied by photoelectron spectroscopy for the case of Ag/polybutene (Ag/PB-1) and Sn/polybutene (Sn/PB-1). While Ag/PB-1 shows the normal behaviour as observed for small particles, e.g., Ag/graphite; Sn/polybutene (Sn/PB-1), which grows epitaxially, shows, in addition, a component at very low coverage, which can be attributed to a Sn-O-C bond at the Sn/PB-1 interface.     

The Local Jahn-Teller Effect in (La/Sr)n+1MnnO3n+1

Lattice polarons play an important role in the mechanism of colossal magnetoresistance in the (La/Sr) _n+1Mn _n O_3n+1 manganites. Local lattice distortions were characterized by the pulsed neutron pair density function (PDF) analysis. The result shows that the doped holes form polarons related to the Jahn–Teller (JT) effect, both in the two-dimensional layered crystals (n=2) and in the perovskites (n=∞). The temperature effects are also similar in both systems suggesting that lattice polarons are largely independent of the crystal symmetry.     

The de Haas-van Alphen effect in Sb(Sn) and Sb(Te) alloys

Measurements have been made of the de Haas-van Alphen effect in Sb(Sn) alloys containing up to 0.58 at % Sn and Sb(Te) alloys with up to 0.26 at % Te. The maximum electron period in the bisectrix-trigonal plane increased from 14.66 × 10^–7 G^–1 in pure Sb to 68.0 × 10^–7 G^–1 in the most concentrated Sn-doped sample, whereas the maximum hole period decreased from 16.33 × 10^–7 to 7.4 × 10^–7 G^–1 . The Te doping had the opposite effect—increasing the number of electrons and decreasing the number of holes. The results of measurements of effective mass and Fermi surface area are found to be consistent with a rigid-band model of these dilute alloys. Both electron and hole bands are strongly nonparabolic and a two-band model is used to estimate that the gap below the electron pocket at L is 110 ± 25 meV. The Fermi levels of electrons and holes in Sb are estimated to be 150 ± 10 and 180 ± 40 meV, respectively. It is predicted that the electron pockets will be completely emptied for an alloy with 0.78 ± 0.07 at % Sn. Pseudopotential calculations suggest that the rigid-band model is a reasonable approximation in these dilute alloys.     

K_(1c)测试试件的尺寸要求和理论依据

本文证明了在裂纹小于某一个跟材料性能有关的值时,K_(lc)=σ_fa~(1/2)·y 为常量这个断裂力学的基本假设不成立。传统的 K_(lc)试件尺寸要求的理论依据是不正确的。在此基础上,通过求出断裂强度的上限而导出了 K_(lc) 公式的有效范围和尺寸要求的表达式。从理论上澄清了以下三个问题:1.为什么 K_(lc)的测试须有尺寸要求?2.怎么要求不同材料的试样尺寸?3.不满足要求时 K_(lc)如何变化?     

Ionic transport studies in Sn(1−x)KxF(2−x) type solid electrolytes

The ionic conductivity of Sn_(1?x)K_xF_(2?x) systems has been investigated as a function of composition and temperature using complex impedance spectroscopy. These materials have been prepared by normal solid state reaction method and characterized through XRD and DSC. The highest conducting sample has been prepared through mechanochemical synthesis technique in addition to solid state reaction method. The universal scaling behavior of the real and imaginary part of the impedance including complex impedance plots indicating temperature independent relaxation behavior has been demonstrated. This result is further supported by the scaling behavior of the real part of the conductivity.     

(1+1)-Dimensional and (2+1)-dimensional waveguides induced by self-focused dark notches and crosses in LiNbO(3):Fe crystal

We demonstrate that (1+1)-dimensional and (2+1)-dimensional waveguides can be induced by self-focused dark notches and crosses and stored in LiNbO(3):Fe crystals. This is very valuable for information processing and integrated optics. The self-focused dark notches and crosses may be related to the formation of (1+1)-dimensional and (2+1)-dimensional photovoltaic dark spatial solitons in LiNbO(3):Fe crystals.