Abstract: Provided is a positive electrode active material capable of achieving a lithium secondary battery having excellent initial charge and discharge efficiency, life characteristics, and thermal stability and a preparation method thereof, wherein the positive electrode active material of the present invention includes a core portion including a lithium transition metal oxide wherein a mole ratio of nickel (Ni) in total transition metals is 80 mol % or more, and a layer-structured shell portion formed on the core portion and including a lithium transition metal oxide in which a molar ratio of manganese (Mn) in the total transition metals is 30 mol % or more, and satisfies Equation 1: 0.005 ? Thickness ? of ? the ? shell ? portion ( ?m ) Average ? particle ? diameter ( D 50 ) ? of ? the ? positive ? electrode ? ? active ? material ( ?m ) ? 0.15 .

Abstract: The present subject matter provides a high-speed nanopatterning method and apparatus of two-color super-resolution photolithography.

Abstract: Disclosed is an endo-microscopic probe based on a non-resonant scanning method using an optical fiber which includes a housing configured to have a specific size, an optical fiber placed within the housing and configured to transfer a light source, a tubular piezoelectric element configured to surround the optical fiber within the housing, include a guide unit for guiding a movement of the optical fiber at the end of the tubular piezoelectric element, and provide a deformation value according to a deformation amount to the optical fiber through the guide unit using an external power source, and a lens unit placed within the tubular piezoelectric element, fixed to an end of the housing, and configured to transfer light output from an end of the optical fiber to a sample.