Fourth‐order autonomous nonlinear differential equations can exhibit chaotic properties. In this study, we propose a family of fourth‐order chaotic systems with infinite equilibrium points whose equilibria form closed curves of different shapes. First, the phase diagrams and Lyapunov exponents (LEs) of the system family are simulated. The results show that the system family has complex phase diagrams and dynamic behaviors. Simulation analysis of the Poincarè mapping and bifurcation diagrams shows that the system has chaotic characteristics. The circuit simulation model is constructed and simulated in Multisim. The circuit simulation results coincide with the numerical simulation results, which verifies the circuit feasibility of the system. Then, based on Lyapunov stability theory and the adaptive control method, the synchronous control of the system with infinite equilibria is designed. Numerical simulation results verify that the system synchronization with the adaptive control method is well. Finally, the synchronous drive system is used for image encryption, the response system is used for decryption, and color image encryption is realized by combining deoxyribonucleic acid (DNA) coding and operating rules. Therefore, this study not only enriched the research on infinite equilibria chaotic systems but also further expanded secure communication technology by combining chaotic synchronization control and DNA coding in image encryption.
Two largest indium ore deposits of 5,000 tons In class in China, Dulong and Dachang mines, studied geochemically. The Dulong deposits have 1000In/Zn value of 4.1 in the average, which is milar to 2.6 of the Changpo-Tongkeng orebody and 3.1 of the Longtaoshan orebody of the Dachang Yet the Dulong ores are depleted in silver and antimony, and enriched in tungsten among the ore while the Dachang ores are rich in silver and antimony similarly to the Toyoha ores occurring in volcanogenic Green Tuff belt in Japan. Concentration of indium in sphalerites is homogeneous in the ores but is strongly banded in the Toyoha ores. It is suggested that the Dulong ore deposits were in a plutonic environment related to S-type ilmenite-series granite, while the Dachang deposits formed at shallower level, related to subvolcanic intrusions. A volcanogenic environment is neces
The Tibetan Plateau has the largest lake cluster in China and in the world. In order to clarify the differences of lake hydrochemistry of Tibetan Plateau, water samples were collected from 32 lakes, including 22 tectonic lakes and 11 glacial lakes, along the Tibetan Plateau road, from September to October 2016. We detected and analyzed the major ion concentrations and characteristics of samples, and discuss the hydrochemistry type, controlling factors, and major ion sources of lake water. The results showed that, firstly, tectonic lake samples on the Tibetan Plateau have much higher physicochemical parameters and ion contents than glacial lakes, and Total Dissolved Solids (TDS) contents fluctuate from high to low latitudes. The variations of ion concentrations in the northern part of the Qiagui Co were more fluctuating and have two obvious peaks, while the variations in the southern part were moderate. The TDS of glacial lakes were low and leveling off in the upper and middle reaches of the basin, while higher and more variable in the lower reaches. Secondly, the tectonic lakes were mainly chloride saline lakes, with Na+ as the major cation, and SO42−, Cl− as the major anions. Glacial lakes were mainly carbonate and sulfate type lakes, Ca2+ and Mg2+ were the major cations, HCO3− was the major anion, and SO42− was the second. Thirdly, the hydrochemistry processes of the tectonic lakes were mainly controlled by evaporation-crystallization, and the ions mainly came from the evaporites of basin. Glacial lake water samples were mainly influenced by the weathering of basin rocks, with ion sources strongly influenced by the weathering of basin carbonates than evaporites, with calcite and dolomite being important sources of Ca2+, Mg2+, and HCO3−.
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