R matrices calculated by Burke and XIoores for electron impact excitation of the 3d 2 D and 4p 2P levels in Ca+ are used. Collision strengths for excitation of fine-structure levels are obtained at energies below and above the threshold for excitation of 4p 2P. These collision strengths are of interest in astrophysics. The polarization of radiation emitted from 2P is related to the cross sections for excitation of the 2P components. Calculated values for these cross sections and for the polarization of the 'P-'S multiplet are given for a range of excitation energies.
The voltage margin of a resistor-logic demultiplexer can be improved significantly by basing its connection pattern on a constant-weight code. Each distinct code determines a unique demultiplexer, and therefore a large family of circuits is defined. We consider using these demultiplexers for building nanoscale crossbar memories, and determine the voltage margin of the memory system based on a particular code. We determine a purely code-theoretic criterion for selecting codes that will yield memories with large voltage margins, which is to minimize the ratio of the maximum to the minimum Hamming distance between distinct codewords. For the specific example of a 64 × 64 crossbar, we discuss what codes provide optimal performance for a memory.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.