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According to the related theory about gas discharge, the
numerical model of a gas discharge tube is established. With the help of
particle simulation method, the curve of relationship between gas ignition
voltage, gas pressure and electrode distance product is studied through
computer simulation on physical process of producing plasma by DC neon
discharge, and a complete consistence between the simulation result and the
experimental curve is realized.
A self-adaptive parallel encryption algorithm based on discrete 2D-Logistic map is developed according to the position scrambling and diffusion of multi-direction in variable space of spatial chaos. The binary sequences b1b2b3···bn are obtained according to the user key, in which the binary sequence 0 and 1 denote distribution mode of processors and the number of binary sequence n denotes cycle number. Then the pseudorandom 2D matrix is generated by 2D-Logistic map, and adaptive segmentation is applied in image matrix and pseudorandom matrix according to the value and the number of binary sequence. The parallel operation is used among blocks to improve efficiency and meet real-time demand in transmission processes. However, the pixel permutation is applied in partitioned matrix through ergodic matrix generated by pseudo-random matrix-block to decrease the correlation of adjacent pixels. Then the pixel substitution is used for fully diffusing through cipher block chaining mode until n cycles. The proposed algorithm can meet the three requirements of parallel operation in image encryption and the real-time requirement in transmission processes. The security is proved by theoretical analysis and simulation results.
This paper studies the announcement effects of the convertible bonds of 50 listed companies in the A-share market of China. The result shows that there are significant negative effects when the convertible bonds are issued, in other words, issuing announcement of the convertible bonds can lead stock prices to decline. However, the significances of the negative effects are different in different markets, bond types, released years and time windows. The volatility of share prices in Shanghai Stock Exchange is less than in Shenzhen Stock Exchange, and the negative effects are more significant than in SZSE. The announcement effect of the ordinary convertible bonds is more significant than the convertible bonds with warrants.