Influence of Mo on the microstructure and mechanical properties of TiC-based cermets

The microstructures and mechanics properties of TiC-based cermets composed of TiC, WC, Ni, Co, Mo, and Cr3C2 were investigated. The results show that Mo has a great effect on the sintering densification, microstructures, and mechanical properties. The microstructures and distribution of Mo and Ti in the TiC-based cermets were analyzed. It was indicated that a new phase with Ti, Mo, W, and C was formed on the rim of （Ti,W）C grains by means of an addition of Mo into the TiC-based cermets. The new phase with a surrounding structure was of great aid to improve the wettability of the liquid phase on the solid phase surface of TiC, decrease the porosity and refine the grains of the hard phase, which gave rise to the increase in strength and hardness. The properties of the TiC-based cermets could be further improved to some extent by adding WC, Cr2C3, and Co.

Effect of Quench Treatment on Fe/Mo Order and Magnetic Properties of Double Perovskite Sr_2FeMoO_6

A quench-treatment technique is used to prepare a high-quality polycrystalline sample of double perovskite Sr2FeMo06 （SFMO）. X-ray powder diffraction analysis reveals that the sample has a single phase and exhibits I4/m symmetry. The cation order η of the sample increases to 98.9（2）% from 94.2（3）%, which is prepared by the traditional sol-gel method. The initial magnetization isotherm of the sample is detected at 300 K. Unit-cell magnetization for the current sample is 1.332 #s at 300 K, and the one for the traditional sol-gel method sample is 0.946#9. Unit-cell magnetization is enhanced to 40.80% by the quench-treatment technique. Quench treatment is an effective method of enhancing the Fe/Mo order and magnetic properties of double perovskite SFMO.

Effect of secondary MO interaction on the regiospecificity in the reactions of α-ionones with singlet oxygen

The eme reactions of α-ionones with singlet oxygen were examined to ascertain the effect of secondary Me interaction between the reactants on the reaction regiospecificity. Exclusive formation of 3-hydroxy-γ-ionones found in the reactions reveals favorable interaction of singlet oxygen with the acyclic α-hydrogen atom,On the other hand,no formation of 3-hy- droxy-β-ionones implies that the steric requirement was not met for the bond formation between zwitterionic perepoxide with C_1-hydrogen in the process.The MMP21 and MNDO calculations indicate minus value of the secondary interaction energy for the aeyelie α-hydrogen abstrac- tion and a repulsion between the oxygen with C_1-hydrogen atom.Twisting tilting of the double bond may account for favorable attack of singlet oxygen on C_3.An explanation of the excellent regiospecificity was addressed and placed in proper mechanic prospective.

Magnetically controllable metasurface and its application

The dynamic control of the metasurface opens up a vital technological approach for the development of multifunctional integrated optical devices.The magnetic field manipulation has the advantages of sub-nanosecond ultra-fast response,non-contact,and continuous adjustment.Thus,the magnetically controllable metasurface has attracted significant attention in recent years.This study introduces the basic principles of the Faraday and Kerr effect of magneto-optical(MO)materials.It classifies the typical MO materials according to their properties.It also summarizes the physical mechanism of different MO metasurfaces that combine the MO effect with plasmonic or dielectric resonance.Besides,their applications in the nonreciprocal device and MO sensing are demonstrated.The future perspectives and challenges of the research on MO metasurfaces are discussed.