Monte Carlo study on abnormal growth of Goss grains in Fe-3%Si steel induced by second-phase particles

The selective abnormal growth of Goss grains in magnetic sheets of Fe-3%Si （grade Hi-B） induced by second-phase particles （AlN and MnS） was studied using a modified Monte Carlo Ports model. The starting microstructures for the simulations were generated from electron backscatter diffraction （EBSD） orientation imaging maps of recrystallized samples. In the simulation, second-phase particles were assumed to be randomly distributed in the initial microstructures and the Zener drag effect of particles on Goss grain boundaries was assumed to be selectively invalid because of the unique properties of Goss grain boundaries. The simulation results suggest that normal growth of the matrix grains stagnates because of the pinning effect of particles on their boundaries. During the onset of abnormal grain growth, some Goss grains with concave boundaries in the initial microstructure grow fast abnormally and other Goss grains with convex boundaries shrink and eventually disappear.

Discussion on the Factors Affecting the Stability of Microgrid Based on Distributed Power Supply

This paper summarizes the advantages of application of micro grid, analyzes the structure of microgrid, and discusses the factors, which are important to the stable operation of micro grid. The factors include the technology of power matching, harmonic suppression and the stability of electronic cascaded systems etc.

Mitigation effect of atorvastatin on cerebral vasospasm after subarachnoid hemorrhage in rats and its effect on expression of Mitofusin-2 and BDNF

Objective:To investigate the mitigation effect of atorvastatin on cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) in rats and its effect on mitochondrial fusion protein 2 (Mitofusin-2) and brain-derived neurotrophic factor (BDNF), which provides an experimental basis and a new method for the prevention and treatment of CVS after SAH.Methods:30 male SD rats were randomly divided into the sham operation group, the model group and the treatment group, with 10 rats in each group. In the model group and the treatment group, the subarachnoid hemorrhage model was made by the double injection of blood in the occipital cistern, and the sham operation group was injected with physiological saline in the same manner. The treatment group was given atorvastatin 20 mg/kg, which was dissolved in 2 mL of distilled water. The sham operation group and the model group were given 2 mL of distilled water. The body weight, mortality, neurological deficit, basilar artery inner diameter, wall thickness and smooth muscle cell apoptosis were observed in the rats 5 d after intervention. The expression levels of Mitofusin-2 and BDNF in each group were observed.Results:The body weight of the three groups was from low to high in the sham operation group, the treatment group and the model group, and the difference was statistically significant. One rat died in the sham operation group and the treatment group, respectively, 2 rats died in the model group and there was no significant difference in mortality between the three groups. The scores of the three groups of neurological function were from low to high among the model group, treatment group and sham operation group, and the difference was statistically significant. The diameter of the three groups of blood vessels was from small to large among the model group, treatment group and sham operation group, and the difference was statistically significant. The apoptotic rate of the three groups of vascular endothelial cells was from small to large among the model group, treatment group and sham operation group, and the difference was statistically significant. The expression levels of Mitofusin-2 were from low to high among the sham operation group, model group and treatment group, respectively.Conclusion:Atorvastatin can alleviate the occurrence of CVS after SAH and alleviate brain tissue damage, and its mechanism may be related to up-regulation of Mitofusin-2 expression.

Nitrogen-doped Zn–Ni oxide for electrochemical reduction of carbon dioxide in sea water

Nitrogen-doped Zn-Ni oxide nanoparticles prepared by ammonia treatment are efficient electrocatalysts for CO_(2) reduction to CO.The single-phase nanostructures of N-Zn-Ni oxide nanoparticles exhibited high electrocatalytic CO_(2) reduction activity with CO Faradaic efficiency of 91.5% and partial current density of 3.2 mA·cm^(-2) at-0.95 V(vs.reversible hydrogen electrode’RHE) in NaCl aqueous solution.Furthermore’ N-Zn-Ni oxides catalyst achieved CO Faradaic efficiency over 89%at—0.8 V(vs.RHE) in natural seawater’ much better than the CO_(2) reduction activity of benchmark Ag/C catalysts in seawater’ and demonstrated strong tolerance to several metal ion impurities with retained CO selectivity.The notable reactivity toward CO_(2) reduction and contamination-tolerance is attributed to peculiar synergistic effect from binary Zn-Ni oxide and nitrogen doping.