4results about How to "Large strain" patented technology

This invention discloses a multi-directional water-impact frequency-upgrading piezoelectric energy harvesting device and method, belonging to the field of piezoelectric material energy harvesting control. The device includes: an outer frame, a cantilever base plate, a piezoelectric sheet, a mass block, a cylindrical water tank, and an elastic film. One end of the cantilever base plate is fixed to the inner side wall of the outer frame, and the other end is fixed to the mass block. The piezoelectric sheet is attached to the cantilever base plate to form a low-frequency drive system. The bottom end of the cylindrical water tank is fixed to the lower surface of the outer frame, and the elastic film is attached to the cavity at the top of the cylindrical water tank to form a high-frequency piezoelectric system. Under external low-frequency vibration excitation, the low-frequency drive system, which has a lower natural frequency, resonates, greatly increasing the vibration amplitude of the water tank. This causes the water in the water tank to continuously and significantly impact the high-frequency piezoelectric system, achieving the purpose of frequency upgrading. This invention utilizes water impact to drive the high-frequency piezoelectric beam to upgrade its frequency, improving the energy harvesting efficiency and output power of the piezoelectric energy harvesting device. Simultaneously, it has advantages such as simple production and assembly, being environmentally friendly and pollution-free, and having a miniaturized structure.

An optical fiber acoustic wave sensitization structure disclosed by the present invention comprises a support, a flexible compliance member and a sheath optical fiber, the flexible compliance member is assembled on the support, the sheath optical fiber is wound on at least part of the surface of the flexible compliance member, the sheath optical fiber comprises a wire core and a sheath, the wire core is a standard single-mode optical fiber, the sheath wraps the wire core, and the flexible compliance member is assembled on the support. The Young modulus of the sheath is lower than the Young modulus of the wire core, the sheath is in contact fit with the flexible compliant component, under the action of external sound pressure, the sheath optical fiber can be directly coupled with sound waves to generate displacement and strain, and the flexible compliant component can deform along with the displacement and strain of the sheath optical fiber. The problems that in the prior art, sound wave energy coupling efficiency is not high, sensitivity is insufficient in a weak sound wave monitoring scene, and a standard single-mode optical fiber is prone to breakage and poor in stability in a complex stress environment are solved.

This application relates to a structural steel plate with a distinct yield plateau and its preparation method, belonging to the field of steel plate manufacturing technology. The chemical composition of the structural steel plate, by mass fraction, includes: C: 0.08%~0.18%, Si: 0.20%~0.40%, Mn: 1.00%~1.70%, P≤0.010%, S≤0.003%, Al: 0.020%~0.050%, Nb: 0.030%~0.110%, V: 0.050%~0.100%, Ti: 0.010%~0.030%, and the matrix element Fe. By optimizing the composition and process, without adding alloying elements such as Cu, Ni, Cr, and Mo, a large number of fine nanoscale Nb, V, and Ti precipitates are formed in the ferrite. These precipitates work synergistically through a dual mechanism: on the one hand, they strengthen the low dislocation density structure to improve the strength of the structural steel plate; on the other hand, they pin dislocations to induce a distinct yield plateau in the structural steel plate. By employing a specific high final cooling temperature process, the coiling or stacking cooling steps are eliminated, shortening the production process and expanding the production capacity of structural steel plate thickness specifications. Ultimately, this results in a significant reduction in alloy costs and an increase in production efficiency, forming a core technological advantage.

The application relates to a silver-coated copper particle, a preparation method thereof and application of the silver-coated copper particle in sintering paste, and belongs to the field of sintering materials. The application solves the problem of high sintering temperature of high-temperature solder in the prior art. The silver-coated copper particle is prepared by a multi-step chemical synthesis method, that is, silver-coated copper particle suspension is prepared first, and then a silver complex solution, a second chelating agent solution and a complexing agent solution are used to realize gradient structure evolution of the silver layer from compact to porous by controlling the release and reduction rate difference of silver ions, the surface of the silver-coated copper particle has a multi-stage pore structure, the contact resistance between particles can be effectively reduced, the sintering starting temperature can be effectively reduced, the poor oxidation performance of copper particles is solved, the silver consumption is reduced, the manufacturing cost is reduced, the ion migration path length and the electromigration life are increased, the silver-coated copper particle prepared by the application greatly meets the requirements of the electronic packaging field for new welding materials, and has remarkable social and economic benefits.