Lorentz transmission electron microscopy studies on topological magnetic domains

Lorentz transmission electron microscopy（TEM） is a powerful tool to study the crystal structures and magnetic domain structures in correlation with novel physical properties. Nanometric topological magnetic configurations such as vortices, bubbles, and skyrmions have received enormous attention from the viewpoint of both fundamental science and potential applications in magnetic logic and memory devices, in which understanding the physical properties of magnetic nanodomains is essential. In this review article, several magnetic imaging methods in Lorentz TEM including the Fresnel and Foucault modes, electron holography, and differential phase contrast（DPC） techniques are discussed, where the novel properties of topological magnetic domains are well addressed. In addition, in situ Lorentz TEM demonstrates that the topological domains can be efficiently manipulated by electric currents, magnetic fields, and temperatures, exhibiting novel phenomena under external fields, which advances the development of topological nanodomain-based spintronics.

Recent advances in catalytic enantioselective direct C–H bond functionalization of electrondeficient N-containing heteroarenes

Catalytic enantioselective direct C–H bond functionalization of electron-deficient N-containing heteroarenes represents one of the most straightforward and powerful protocols to construct diverse enantioenriched highly functionalized N-heteroarene products.Efficient catalytic systems and a variety of strategies for highly chemo-and stereoselective C–H functionalization of electron-deficient N-containing heteroarenes have been developed over the past few decades.This review summarized the rapid progress in the catalytic asymmetric C–H functionalization of N-containing heteroarenes and discussed the challenges and potential of the field in the current stage.