Abstract. It is shown that the transverse plasmon field is modulationally unstable in the Lyapunov sense, leading to a self-similar collapse of the magnetic flux. Such a collapsing magnetic instability is analyzed in both cases of magnetohydrodynamics and kinetic plasma physics, with their applications to solar intermittent flux and anomalous viscosity in accretion disks, respectively. In the first case, we find that the equilibrium between the ponderomotive force and the Lorentz force in a current sheet gives rise to a more spatially intermittent collapsing magnetic flux, very similar to a turbulent pattern; as a result, the 0.1 kG flux cells with larger scales emerging at the surface from the solar interior become shredded and the flux is thereby contracted rather quickly to a small scale of the order of 100 km as well as concentrated into a 1-2 kG state. In the second case, based on Vlasov equations and Maxwell equations, the collapsing feature of the self-generated magnetic field from transverse plasmons is investigated on rather small scales of the motion or electric current in accretion disks; as the effects of the intermittent magnetic flux, an anomalous magnetic viscosity and an anomalous resistivity are indicated, with a different magnetic Prandtl number, which is not very sensitive to the temperature T .

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The approach coupled with computation fluid dynamics (CFD) and complex chemical kinetic computation to predict the oxidation of the elemental mercury in flue gas was discussed in this paper. According to the oxidation mechanism of the elemental mercury, the reactions which were in close relationship with mercury oxidation were determined by the sensitivity analysis method. The mercury oxidation process was simulated under the atmospheric pressure condition with different flue-gas compositions. The three-dimensional concentration distribution of mercury within the cylindrical flue duct and the impact of the temperature, concentration of Cl 2 , HCl, NO, and O 2 on the mercury oxidation were also obtained. The simulation results were compared with the experimental results of Mamani-Paco and Widmer. The results show that coupling computation solves the problem of the combination of the CFD with the complex kinetic mechanism. The promotion effect of Cl 2 on the oxidation of elemental mercury is much better than that of HCl. The temperature window ranged from 950 to 1,150 K for the higher oxidizing rate of the elemental mercury was determined. The slight enhancement of NO on mercury oxidization was observed which was controlled by the competition between two reaction pathways. O 2 weakly promotes homogeneous Hg oxidation, especially under the condition of high temperature. 1.1, 2.6 and 3.1 % of mercury was oxidized in the presence of 0, 4 and 16 % O 2 at 600 K, respectively. However, 12.5, 22.5 and 26.0 % of Hg oxidation has been obtained at 1,200 K.

Reconnective annihilation of magnetic field leads to the formation of magnetic flux cells with small scales, followed by enhanced transverse plasmons occurring in a thin current sheet with a very small vertical extent. The analysis here focuses on the nonlinear interaction between the flux and plasmons. The transverse plasmon field is modulationally unstable in the Lyapunov sense. When the initial pumping wave amplitude attains the threshold of instability, this instability occurs with a high growth rate. Nonlinear development of modulational instability eventually results in self-similar collapse, due to nonlinear equilibrium, giving rise to a spatially intermittent, collapsing magnetic flux, very similar to a turbulent pattern. The Maxwell stress tensor from the turbulence flux determines the anomalous magnetic viscosity, i.e. the parameter α. It is shown that the instability is responsible for the alternation of outburst or quiescent states in astrophysical accretion disks. When the instability occurs, the parameter α is large. In the quiescent state, the instability is suppressed, leading to a smaller, collapse-quenching value of α.