Abstract: A control valve structure, a using method thereof, a microfluidic chip, and a nucleic acid extraction device. The control valve structure includes: a cover plate layer, a first channel layer, a first adhesive layer, a second channel layer, at least one valve core, and at least one elastic film. When the valve core is embedded in the first limiting hole, the elastic film seals the first limiting hole, and the second limiting hole, the first through hole and the liquid outlet channel form a sample liquid flow channel; and when the valve core is embedded in the second limiting hole, the elastic film seals the second limiting hole so as to block the sample liquid flow channel.

Abstract: The invention discloses a ternary positive electrode material coated with nitride/graphitized carbon nanosheets and preparation method thereof. The ternary positive electrode material coated with nitride/graphitized carbon nanosheets includes a ternary positive electrode material matrix and a coating layer; the coating layer is composed of nitride and graphitized carbon; and the graphitized carbon is formed in situ in the coating process of the nitride. Compared with a physical mixing method, the in-situ generated carbon layer is connected to the material matrix more tightly, and the formed conductive network is denser. So that the rate performance of the material is improved to the maximum extent. The preparation method is simple and easy to realize industrial production. And the obtained ternary positive electrode material coated with nitride/graphitized carbon nanosheets has excellent rate performance and cycling stability.