Abstract: A graphene reinforced aluminum matrix composite with high electrical conductivity and a preparation method thereof. The method includes: obtaining aluminum coated graphene powder by plating aluminum on a graphene surface, melting aluminum block into aluminum liquid, heating a mold to be lower than an aluminum melting point, alternately pouring the aluminum liquid and the aluminum coated graphene powder into the mold for layered casting to obtain a sandwich structure; extruding the sandwich structure into a rectangular test block and then heating to 500˜600° C., performing heat preservation for a preset time and performing forging treatment, and performing longitudinal cold deformation under inert gas to obtain the graphene reinforced aluminum matrix composite. The method can solve a problem that poor wettability of graphene and aluminum matrix, the graphene is evenly dispersed in the aluminum matrix, which can improve strength of the aluminum matrix and keep its high electrical conductivity.

Abstract: A graphene reinforced aluminum matrix composite with high electrical conductivity and a preparation method thereof. The method includes: obtaining aluminum coated graphene powder by plating aluminum on a graphene surface, melting aluminum block into aluminum liquid, heating a mold to be lower than an aluminum melting point, alternately pouring the aluminum liquid and the aluminum coated graphene powder into the mold for layered casting to obtain a sandwich structure; extruding the sandwich structure into a rectangular test block and then heating to 500˜600° C., performing heat preservation for a preset time and performing forging treatment, and performing longitudinal cold deformation under inert gas to obtain the graphene reinforced aluminum matrix composite. The method can solve a problem that poor wettability of graphene and aluminum matrix, the graphene is evenly dispersed in the aluminum matrix, which can improve strength of the aluminum matrix and keep its high electrical conductivity.

Abstract: The present invention provides a super-hydrophobic anti-pollution flashover coating with hydrophobicity transference, which is prepared from the following raw materials: a silicone resin, an organic solvent, silicon oxide, a flame retardant, a cross-linking agent, a coupling agent, a dispersing agent, a defoaming agent, a leveling agent, and a silicone resin curing agent. The present invention also provides a preparation method of the super-hydrophobic anti-pollution flashover coating with hydrophobicity transference.

Abstract: A method is disclosed of fabricating all-dielectric flat lens with low refractive index comprising: selecting dielectric substrate material and lens structure material; determining incident wavelength; calculating phase modulation corresponding to each pillar unit; periodically sampling circular area of dielectric substrate with radius to obtain plurality of sampling points; calculating phase modulation required at position of each sampling point; obtaining pillar corresponding to each sampling point; arranging different dielectric pillars with low refractive index and same thickness are arranged on dielectric substrate, thereby obtaining all dielectric flat lens with low refractive index.

Abstract: A screw drill bypass valve comprising a valve body, the valve body is internally provided with a first-level valve core and a second-level valve core, a first-level spring is arranged between the first-level valve core and the second-level valve core, a second-level spring is arranged between the second-level valve core and a valve seat, and a rigidity of the second-level spring is greater than that of the first-level spring; the first-level valve core is provided with an inner bypass hole, the valve body is provided with an outer bypass hole, and the inner bypass hole is conducted with the outer bypass hole when a flowing pressure within a fluid channel of drilling fluid disappears; the second-level valve core is provided with an inner diversion hole, the valve body is provided with an outer diversion hole.

Abstract: Disclosed are a screw drill bypass valve with a large displacement diversion function and a method of using same.

Abstract: A method is disclosed of fabricating all-dielectric flat lens with low refractive index comprising: selecting dielectric substrate material and lens structure material; determining incident wavelength; calculating phase modulation corresponding to each pillar unit; periodically sampling circular area of dielectric substrate with radius to obtain plurality of sampling points; calculating phase modulation required at position each sampling point; obtaining pillar corresponding to each sampling point; arranging different dielectric pillars with low refractive index and same thickness are arranged on dielectric substrate, thereby obtaining all dielectric flat lens with low refractive index.

Abstract: A method for providing a group chat service includes: creating a chat group including a first member and one or more second members; establishing a P2P connection to each of the second members; receiving audio data uploaded from the second members through the P2P connections; mixing the audio data received and audio data of the first member to generate mixed audio data and transmitting the mixed audio data to the second members through the P2P connections by the first member; receiving by the second members the mixed audio data. The present invention also discloses a system for providing a group chat service. According to the present invention, text chat and audio chat are handled differently, thus the network bandwidth requirement and computer hardware requirement of group chat for forwarding the audio data are lowered, and the data volume transmitted by the network is reduced.