In this paper, we consider a discrete version of Aleksandrov＇s projection theorem. We prove that an origin-symmetric convex lattice set, whose lattice＇s y-coordinates＇ absolute values are not bigger than 2, can be uniquely determined by its lattice projection counts if its cardinality is not 11. This partly answers a question on the discrete version of Aleksandrov＇s projection theorem which was proposed by Gardner, Gronchi and Zong in 2005.
Motivated by Problem 164 proposed by Y. Berkovich and E. Zhmud＇ in their book ＂Characters of Finite Groups＂, we give a characterization of finite groups whose irreducible character codegrees are prime powers. This is based on a new kind of character graphs of finite groups associated with codegrees. Such graphs have close and obvious connections with character codegree graphs. For example, they have the same number of connected components. By analogy with the work of finite groups whose character graphs （associated with degrees） have no triangles, we conduct a result of classifying finite groups whose character graphs associated with codegrees have no triangles in the latter part of this paper.
Let F be a saturated fusion system over a finite p-group S, and let Z ≤ Zn （F）, which is strongly closed in S with respect to F. In this paper, we prove that there is a natural bijection from the set of normal subsystems of 7 containing Z to the set of normal subsystems of the factor system F＋ =F/Z. This generalizes a result of Aschbacher.
基于Global Foundries 0.18μm CMOS工艺,设计了一种用于10bit 10MSPS SAR ADC的栅压自举采样开关电路.讨论了互补型CMOS采样开关和传统的栅压自举采样开关的不足,提出了一种新型的栅压自举采样开关电路结构,有效地提高了该电路的可靠性.仿真结果表明:当输入信号频率接近奈奎斯特频率时,该栅压自举采样开关电路的信噪比可以达到72dB,可以适用于10bit 10MSPS SAR ADC的应用需求.
