A relationship between the Berlekamp-Massey and the euclidean algorithms for linear feedback shift register synthesis

A relationship between the Berlekamp-Massey and the Euclidean algorithms for linear feedback shift register synthesis is established. In fact, by refining a sequence of polynomials appearing in the Euclidean algorithm, the sequence of characteristic polynomials computed by the Berlekamp-Massey algorithm will be achieved. A preliminary version of this paper was presented at the Oberwolfach Information Theory Meeting, May 12–16, 1986.     

Asymptotic behavior of solutions for a class of retarded difference equations

Consider the retarded difference equationx _n −x _n−1 =F(−f(x _n )+g(x _n−k )), wherek is a positive integer,F,f,g:R→R are continuous,F andf are increasing onR, anduF(u)>0 for allu≠0. We show that whenf(y)≥g(y) (resp. f(y)≤g(y)) fory∈R, every solution of (*) tends to either a constant or −∞ (resp. ∞) asn→∞. Furthermore, iff(y)≡g(y) fory∈R, then every solution of (*) tends to a constant asn→∞. Project supported by NNSF (19601016) of China and NSF (97-37-42) of Hunan     

Surface electronic structure of binary metal oxide catalyst ZrO2/SiO2

The surface electronic structure of the binary metal oxide ZrO₂/SiO₂ was studied by means of XPS and the decrete variational (DV) Xα cluster model calculation. The results show that when ZrO₂, was supported on SiO₂, the SiO bond of SiO₂, neighboring ZrO₄, became stronger and that the Brönsted acid site H which is located on the SiO₄ unit exhibits stronger acidity.     

N2O+离子A2Σ+电子态的光解动力学研究

用一束波长为360.55nm的激光，通过N2O分子的（3+1）共振多光子电离（REMPI）过程制备纯净且布居完全处于X2Π(000)态的母体离子N2O+，然后用另一束波长在275—328nm范围内的可调谐激光将制备的N2O+离子激发至预解离电子态A2Σ+.实验发现，由于解离碎片NO+所具有的一定的反冲速度，其TOF质谱峰明显比N2O+母体宽.通过分析NO+碎片TOF质谱峰形状，得到了解离产物的总平均平动能〈ET〉；通过考察〈ET〉随光解能量的变化，发现光解能量在32000cm-1附近约250cm-1的变化 关键词： N2O+离子A2Σ+态 TOF质谱峰 预解离机理     

Physical and chemical properties of tussah silk fibroin films

Physical and chemical structure, as well as thermal behavior of solution-cast regenerated films, prepared from tussah (Antheraea pernyi) silk fibroin, were compared with those of solution-cast native films, in order to ascertain whether treatment (degumming, dissolution) used for preparation affected their properties. Regenerated fibroin films exhibited a higher thermal stability than native ones, as shown by differential scanning calorimetry, thermomechanical analysis, and dynamic mechanical behavior. Glass transition temperature and other relevant thermal transitions of the regenerated silk specimen shifted to higher temperatures compared with those of native specimen. Molecular conformation and crystalline structure did not show significant differences between the two kinds of silk films. Amino acid composition and molecular weight, however, distribution changed markedly after dissolving tussah silk fibroin fiber in concentrated LiSCN in polypeptide size was the main features for the regenerated silk fibroin. © 1994 John Wiley & Sons, Inc.     

The orbit method and the Virasoro extension of Diff(S): I. Orbital integrals

Using the finite dimensional example of , the universal covering of PSU(1,1), as a guide, we revisit the orbit method as it applies to , the universal central extension of . We clarify some aspects of the classification of coadjoint orbits, determine boundedness properties of the natural height function on these orbits, and calculate orbital integrals.     

关于电磁学教学的三点建议

本文就电磁学教学中常遇到的问题谈一点教学体会。