Abstract: A rivet with improved structure for forming flat-bottom riveting of plates, which comprises a rivet cover, a rivet shoulder and a rivet body; specifically, the rivet cover is provided with a torque transmission structure and a positioning structure for driving the rivet to rotate; the rivet body comprises an inner cavity of the rivet body, an outer wall of the rivet body and an end of the rivet body; with the present invention, the bottom surface of the joint can be flush with the surface of the connected plates, which facilitates the subsequent processing of the coverage on the bottom surface, reduces the wind resistance coefficient of the joint, and broadens the application range of the process.

Abstract: The present invention provides a rare earth hard alloy and a preparation method and application thereof. The rare earth hard alloy includes 6 to 15 wt % of a binding phase and the balance of a hard phase, wherein the binding phase includes 30 to 50 wt % of Ni3Al, 0.1 to 0.5 wt % of a rare earth element and the balance of Ni. According to the rare earth hard alloy provided by the invention, the Ni—Ni3Al-rare earth element (e.g., Ni—Ni3Al—Y)-based binding phase is strengthened by Ni3Al, and an ordered strengthening phase is formed and is diffused and distributed in the binding phase, such that the rare earth hard alloy has a better high-temperature oxidation resistance, a better room-temperature fracture toughness and a better high-temperature bending strength than a conventional hard alloy.

Abstract: A rivet with improved structure for forming flat-bottom riveting of plates, which comprises a rivet cover, a rivet shoulder and a rivet body; specifically, the rivet cover is provided with a torque transmission structure and a positioning structure for driving the rivet to rotate; the rivet body comprises an inner cavity of the rivet body, an outer wall of the rivet body and an end of the rivet body; with the present invention, the bottom surface of the joint can be flush with the surface of the connected plates, which facilitates the subsequent processing of the coverage on the bottom surface, reduces the wind resistance coefficient of the joint, and broadens the application range of the process.

Abstract: A rivet rotational feeding method for friction self-piercing riveting (F-SPR) system, comprising: a semi-hollow rivet, a driving spindle and a die. The bottom surface of the rivet head is connected to the semi-hollow rivet shank. The semi-hollow rivet shank has a wedge-shaped end. The rivet head has rotation driving structures and positioning structure on the top end. The rotation driving structures are central symmetric concave or convex surfaces. The positioning structure is a central symmetric and mirror symmetric concave or convex surface. The matching between the driving spindle and the rivet can improve the rotation reliability and positioning accuracy of the riveting at a high rotational speed during F-SPR process, which is beneficial to solve the problems of poor stability and non-coincidence between the geometry axis and the rotation axis of the rivet.

Abstract: A rivet rotational feeding method for friction self-piercing riveting (F-SPR) system, comprising: a semi-hollow rivet, a driving spindle and a die. The bottom surface of the rivet head is connected to the semi-hollow rivet shank. The semi-hollow rivet shank has a wedge-shaped end. The rivet head has rotation driving structures and positioning structure on the top end. The rotation driving structures are central symmetric concave or convex surfaces. The positioning structure is a central symmetric and mirror symmetric concave or convex surface. The matching between the driving spindle and the rivet can improve the rotation reliability and positioning accuracy of the riveting at a high rotational speed during F-SPR process, which is beneficial to solve the problems of poor stability and non-coincidence between the geometry axis and the rotation axis of the rivet.

Abstract: A programming assistance technical solution for a framework-based application program. The application program contains program files and configuration files, including: processing configuration files of an application program history base into a configuration file classification base according to types of frameworks; constructing a Closed Frequent Subtree Set according to the configuration file classification base and determining a support of the Closed Frequent Subtree; and providing the Closed Frequent Subtree Set and the support for programming assistance. The technical solution of the present invention can be employed to assist in programming of a framework-based application program.

Abstract: A programming assistance technical solution for a framework-based application program. The application program contains program files and configuration files, including: processing configuration files of an application program history base into a configuration file classification base according to types of frameworks; constructing a Closed Frequent Subtree Set according to the configuration file classification base and determining a support of the Closed Frequent Subtree; and providing the Closed Frequent Subtree Set and the support for programming assistance. The technical solution of the present invention can be employed to assist in programming of a framework-based application program.

Abstract: The current invention relates to the design, synthesis, and biochemical evaluation of chromogenic substrate compounds for sialidases of bacterial, viral, protozoa, and vertebrate (including human) origin. In particular, this invention provides a novel class of effective compounds as chromogenic substrates of these sialidases which yield chromogenic products after reactions catalyzed by sialidase take place. Also provided are methods of making these substrate compounds, methods of diagnosis and prognosis of sialidase related diseases using these substrate compounds.