Abstract: Disclosed is a preparation method for a single-crystal sodium-ion battery cathode material. The single-crystal sodium-ion battery cathode active material comprises: sodium, metal M, boron, and oxygen elements, and the preparation method comprises a step of adding an M-containing compound, a B-containing compound and a sodium source to water to form a slurry and sand grinding the slurry to obtain a mixed slurry and a step of spray drying the mixed slurry and sintering the dried mixed slurry to obtain the single-crystal sodium-ion battery cathode active material. The preparation method can be applied to a wide variety of raw materials, and can efficiently achieve uniform mixing of multiple raw materials at the nano level. After being sintered, the mixed slurry can form a perfect layered O3 phase structure. The prepared single-crystal sodium-ion battery cathode material has excellent electrochemical performance and cycle performance when used in a sodium-ion battery.

Abstract: Disclosed are a cathode active material for sodium-ion batteries and a preparation method therefor and an application thereof. The cathode active material has a chemical formula of NaxNiyFezMngMhAmO2, where M is selected from the group consisting of Ti, Al, Mg, Ca, Zr, Y, Zn, Nb, W and combinations thereof, A is selected from the group consisting of B, P, C and combinations thereof, 0.80?x?1.40, 0.05?y?0.95, 0.05?z?0.95, 0.05?g?0.95, 0.01?h?0.50, and 0.01?m?0.30. By adding M and A elements to the ternary iron-manganese-nickel cathode active material for sodium-ion batteries, and controlling the ratio of all elements, the present disclosure can achieve the formation of a perfect layered single-crystal structure of the cathode active material for sodium-ion batteries, with large particles, ultimately achieving the stability of the active material, and when used in sodium-ion batteries, it can significantly improve the cycling performance at high temperatures while ensuring high gram capacity.

Abstract: A fan device includes a hub and a plurality of fan blades. Each of the fan blades includes a driving surface, and the driving surface includes a first tooth column and a second tooth column. The first tooth column includes a plurality of first skin-tooth units. Each of the first skin-tooth units includes a first body. A first middle ridge and two first side ridges protrude from a surface of the first body, and a groove is formed between two adjacent first skin-tooth units. The second tooth column includes a plurality of second skin-tooth units. Each of the second skin-tooth units includes a second body and an extension element. A second middle ridge and two second side ridges protrude from a surface of the second body, and the extension element is located in the groove and includes an extension rib.

Abstract: Disclosed are a cathode active material for sodium-ion batteries and a preparation method therefor and an application thereof. The cathode active material has a chemical formula of NaxNiyFezMngMhAmO2, where M is selected from the group consisting of Ti, Al, Mg, Ca, Zr, Y, Zn, Nb, W and combinations thereof, A is selected from the group consisting of B, P, C and combinations thereof, 0.80?x?1.40, 0.05?y?0.95, 0.05?z?0.95, 0.05?g?0.95, 0.01?h?0.50, and 0.01?m?0.30. By adding M and A elements to the ternary iron-manganese-nickel cathode active material for sodium-ion batteries, and controlling the ratio of all elements, the present disclosure can achieve the formation of a perfect layered single-crystal structure of the cathode active material for sodium-ion batteries, with large particles, ultimately achieving the stability of the active material, and when used in sodium-ion batteries, it can significantly improve the cycling performance at high temperatures while ensuring high gram capacity.

Abstract: A wireless ultrasound sensor 404 for non-destructive testing of a test object 502, the sensor comprising: an ultrasound transducer 406; a first induction coil 408, electrically coupled to the ultrasound transducer; a second induction coil 414, electrically coupled in parallel with the first induction coil; wherein the first and second induction coils are arranged to enable the transducer to be inductively operated by a remote device 504; and wherein the diameter of the second induction coil is greater than the diameter of the first induction coil.

Abstract: A fan device includes a hub and a plurality of fan blades. Each of the fan blades includes a driving surface, and the driving surface includes a first tooth column and a second tooth column. The first tooth column includes a plurality of first skin-tooth units. Each of the first skin-tooth units includes a first body. A first middle ridge and two first side ridges protrude from a surface of the first body, and a groove is formed between two adjacent first skin-tooth units. The second tooth column includes a plurality of second skin-tooth units. Each of the second skin-tooth units includes a second body and an extension element. A second middle ridge and two second side ridges protrude from a surface of the second body, and the extension element is located in the groove and includes an extension rib.

Abstract: A wireless ultrasound sensor 404 for non-destructive testing of a test object 502, the sensor comprising: an ultrasound transducer 406; a first induction coil 408, electrically coupled to the ultrasound transducer; a second induction coil 414, electrically coupled in parallel with the first induction coil; wherein the first and second induction coils are arranged to enable the transducer to be inductively operated by a remote device 504; and wherein the diameter of the second induction coil is greater than the diameter of the first induction coil.

Abstract: A wireless ultrasound sensor 404 for non-destructive testing of a test object 502, the sensor comprising: an ultrasound transducer 406; a first induction coil 408, electrically coupled to the ultrasound transducer; a second induction coil 414, electrically coupled in parallel with the first induction coil; wherein the first and second induction coils are arranged to enable the transducer to be inductively operated by a remote device 504; and wherein the diameter of the second induction coil is greater than the diameter of the first induction coil.

Abstract: A method for generating a group key are provided in the field of network communications. The method includes the following steps: Group members select DH secret values and generate DH public values. An organizer generates an intermediate message and broadcasts a DH public value and the intermediate message. The group members generate a group key according to a DH secret value selected by the organizer and DH public values of the other group members except the organizer. A system for generating a group key and communication devices are also disclosed in the present invention.

Abstract: A method for generating a group key are provided in the field of network communications. The method includes the following steps: Group members select DH secret values and generate DH public values. An organizer generates an intermediate message and broadcasts a DH public value and the intermediate message. The group members generate a group key according to a DH secret value selected by the organizer and DH public values of the other group members except the organizer. A system for generating a group key and communication devices are also disclosed in the present invention.