Invariance of selfinjective algebras of quasitilted type under stable equivalences

We prove that the class of finite dimensional selfinjective algebras over a field which admit Galois coverings by the repetitive algebras of the quasitilted algebras, with Galois groups generated by compositions of the Nakayama automorphisms with strictly positive automorphisms, is invariant under stable and derived equivalences. Dedicated to Claus Michael Ringel on the occasion of his sixtieth birthday     

Molecular dynamics studies of brittle fracture in vitreous silica: Review and recent progress

The dynamics of brittle fracture in vitreous silica has been a subject of many molecular dynamics (MD) simulations and experiments. A striking similarity between both simulations and experiments is the observation of nanoscale voids that eventually coalesce leading to failure. In this work, we review the above MD simulations and carry out further MD investigations using two variations of classical 2-body potentials. We study the effect of charge-transfer, an important aspect neglected by previous simulations. Further, we examine the growth of ‘critical’ voids and characterize regions surrounding the voids.     

同步相机测量任意频率光信号时的S/N理论分析

本文从理论上分析了同步扫描相机在测量由双波长激光器产生的差频信号时信噪比的问题.这一差频信号的频率和同步相机的扫描频率并非整数倍关系.我们从光电阴极的发射噪音(shotnoise)理论出发,得出了在这种特殊应用情况下相机的信嗓比比正常应用情况下(即入射光脉冲的频率和扫描频率为整数倍关系)至少要小23倍.     

右连续上鞅的提升及其应用

本文首先给出了一个右连续上鞅的ＳＤ提升，在引进Ｓ－上鞅和强Ｓ－上鞅概念之后，研究了一一致可积上鞅与Ｓ－上鞅，类上鞅与强Ｓ－上鞅之间的关系，并得到了Ｓ－上鞅与强Ｓ－上鞅的许多性质，作为其直接结果，给出了类上鞅的Ｄｏｏｂ－ＭＮｅｙｅｒ分解。     

Proton–neutron structure of the N=52 nucleus Zr

Following the successful identification of mixed-symmetric one- and two-phonon states in the N=52 nuclei ⁹⁴Mo and ⁹⁶Ru, we have performed a photon scattering experiment on the N=52 isotone ⁹²Zr. Experimental data and shell model calculations show that both, single particle and collective degrees of freedom are present in the low-lying levels of ⁹²Zr. The second excited quadrupole state shows the signatures of the one-phonon mixed-symmetric 2⁺ state, while calculations and data indicate an almost pure neutron configuration for the 2⁺₁ state, in contradiction with the F-spin symmetric limit. Furthermore, two strong dipole excitations, which are candidates for the two-phonon quadrupole–octupole coupled E1 excitation and for the mixed-symmetric 1⁺ two-phonon state, were observed.     

闪耀型彩虹全息术

彩虹全息术中的长狭缝演化为一个点，可极大提高再现像的亮度，文中阐述了这种闪耀型彩虹全息图制版光路，论证了在明视距离处形成出射瞳孔实像的条件，指出了这种多色显示的全息图有高信噪比。     

Bounded decomposition in the Brieskorn lattice and Pfaffian Picard-Fuchs systems for Abelian integrals

We suggest an algorithm for derivation of the Picard-Puchs system of Pfaffian equations for Abelian integrals corresponding to semiquasihomogeneous Hamiltonians. It is based on an effective decomposition of polynomial forms in the Brieskorn lattice. The construction allows for an explicit upper bound on the norms of the polynomial coefficients, an important ingredient in studying zeros of these integrals.     

H2S2分子的阻碍内旋转势能函数

应用无波函烽微扰理论导出了分子障碍内旋转能谱的解析式，基于扭转频率光谱数据，确定了Ｈ２Ｓ２分子的阻碍内旋转势能函数。     

Properties and examples of FCR-algebras

An algebra A over a field k is FCR if every finite dimensional representation of A is completely reducible and the intersection of the kernels of these representations is zero. We give a useful characterization of FCR-algebras and apply this to C ^*-algebras and to localizations. Moreover, we show that “small” products and sums of FCR-algebras are again FCR. Received: 25 October 2000