13results about How to "Improve the attenuation effect" patented technology

The application discloses a kind of high resilience self-repairing polyurethane elastomer and preparation method thereof.The preparation method includes the pre-polymerization of secondary amine end-capped polyether amine and diisocyanate in organic solvent, to obtain isocyanate end-capped prepolymer;Diamine and / or hydrazine chain extender are added to the prepolymer to carry out chain extension reaction, to obtain chain extension product containing urea bond and hydrazine bond;Trifunctional isocyanate crosslinking agent is added to the chain extension product to carry out crosslinking reaction, and after reaction to gelation critical point, it is formed by pouring into shape.The application constructs the interpenetrating double network structure of high-density multiple hydrogen bond physical network and dynamic covalent bond chemical network interpenetration, so that the resilience of elastomer reaches 92.7%~95% under 100%~300% strain, and the self-repairing efficiency reaches more than 72% after 12h repair at room temperature without external stimulation, realizes the synergistic improvement of high resilience, high tensile and high-efficiency self-repairing performance, and can be used in flexible electronic devices, wearable sensors and flexible substrates in biological medical detection equipment.

This utility model relates to the field of bridge technology and discloses a damping and vibration-damping multi-directional displacement comb-plate bridge expansion joint, including the main bridge side and the approach bridge side. This damping and vibration-damping multi-directional displacement comb-plate bridge expansion joint is equipped with a fixed frame, a fixed box, a disc spring assembly, a wear-resistant sleeve, a sphere, threaded holes, a mounting groove, a pad, and fixing bolts. Through the cooperative design of the wear-resistant sleeve and the sphere, the sphere can rotate freely within the wear-resistant sleeve. The threaded holes on its inner wall facilitate connection with the fixing bolts. When the fixed comb plate undergoes angular displacement, the rotation of the sphere and the elastic deformation of the disc spring assembly work together to effectively disperse stress and avoid localized stress concentration in the comb plate. Compared to existing technologies that rely solely on the elastic deformation of the disc spring assembly to achieve angular displacement, this device can better adapt to the longitudinal, lateral, and vertical composite deformations generated by bridges under complex working conditions, greatly reducing the risk of component damage.

The invention discloses a thermally-induced rigidity-variable high-performance mounting bracket and a control method thereof, relates to the technical field of vibration reduction equipment, and aims to solve the technical problem that an existing vehicle-mounted motor vibration reduction bracket cannot be adaptively adjusted along with temperature change. Through the TiNiNb shape memory alloy pull column, temperature self-adaption rigidity switching, low-temperature rigidity fixing impact resistance and normal-high-temperature flexible vibration reduction are achieved, and vibration characteristics of different temperature ranges of the motor are adapted; the vibration buffering gasket is matched with the air damping mechanism to form double vibration reduction, and the high-frequency broadband vibration attenuation effect is greatly improved through the triple damping effect; the ventilation air bag realizes forced air circulation by means of motor vibration, vibration reduction heat is quickly discharged, and high-temperature vibration reduction stability is guaranteed; the vibration wave mechanism is matched with the one-way shaft ring, vibration is converted into reverse rotation force of the radial vibration buffering ring, eccentric radial vibration force of the rotor is counteracted from the source, and accurate radial vibration reduction is achieved.

The application discloses a glass frit for a single-crystal silicon solar cell front paste, a paste, and a single-crystal silicon solar cell. The glass frit comprises 1-30 mol% of lithium oxide, 5-40 mol% of bismuth oxide, 5-40 mol% of lead oxide, 1-40 mol% of silicon oxide, and X, wherein X is any one or a mixture of several of copper oxide, cesium oxide, rubidium oxide, sodium oxide, potassium oxide, aluminum oxide, magnesium oxide, strontium oxide, tin oxide, zinc oxide, or tungsten oxide, and the molar content of any one of the oxides in X is 1-10 mol%, and the content of X is not more than 50 mol%. The conductive paste prepared by using the glass frit contains a lead-bismuth-silicon oxide glass system, the system has enhanced resistance to acetic acid attenuation, ensures a sintering window at a high-temperature fast-firing sintering temperature, and X has strong corrosiveness, so that a lower contact area can be obtained. The conductive paste has high resistance to acetic acid in a wide sintering window.

The application provides a bus driver structure and a control method, which comprise: a high-side drive circuit; the high-side drive circuit is connected between a power supply and a load. The high-side drive circuit comprises: a high-side first transistor, a high-side second transistor and a high-side reverse current blocking unit; the gate of the high-side first transistor and the gate of the high-side second transistor are respectively connected to a high-side gate control unit; the drain of the high-side first transistor is connected to the power supply, and the source of the high-side first transistor is connected to the positive electrode of the high-side reverse current blocking unit; the drain of the high-side second transistor is connected to the negative electrode of the high-side reverse current blocking unit, and the source of the high-side second transistor is a high-side signal end; and the high-side signal end is used for directly or indirectly connecting the load. The bus driver structure can solve the problems of complex control circuit, high cost and slow overcurrent protection reaction speed in the prior art.

The utility model discloses a filter for medical frequency converter, including connector J1 and connector J2, the one foot of connector J1 is connected respectively piezo -electric resistance MOV1, piezo -electric resistance MOV3, inductance L1 one foot, electric capacity C2 and electric capacity C3, piezo -electric resistance MOV1 other end connects inductance L1 three feet, piezo -electric resistance MOV3 other end connects gas discharge tube and piezo -electric resistance MOV2 respectively, gas discharge tube ground connection, piezo -electric resistance MOV2 other end connects inductance L1 three feet, electric capacity C2 other end connects electric capacity C1, electric capacity C1 ground connection, electric capacity C3 other end ground connection, inductance L1 two feet connects electric capacity C5, electric capacity C4, resistance R1 and inductance L2 one foot respectively, electric capacity C4 other end ground connection, resistance R1 other end connects electric capacity C10, electric capacity C10 ground connection, electric capacity C5 other end connects inductance L1 four feet.

The invention relates to the technical field of alloy coating materials, and particularly discloses an anti-oxidation coating for a high-pressure hot-pressing mold and a preparation method of the anti-oxidation coating. The high-pressure hot-pressing mold anti-oxidation coating comprises a transition layer and a functional layer which are sequentially arranged from a mold base body to the outside, the transition layer is a TiN-SiC gradient composite layer, the functional layer takes Al2O3-NiCrAlY as a base body, and nano ZrB2 and rare earth CeO2 which are subjected to double modification treatment are compositely doped; and the dual-modified nano ZrB2 is ZrB2 particles which are coated with a silane coupling agent KH-560 and a NiCr alloy. The anti-oxidation coating of the high-pressure hot-pressing mold has both oxidation resistance and wear resistance, and the high-temperature hardness stability and wear resistance of the anti-oxidation coating are effectively enhanced.

This application provides a headphone sound transmission device and a headphone. The headphone sound transmission device includes a sound transmitting element and a sound receiving element; the sound transmitting element has a first sound transmission channel and a second sound transmission channel that are interconnected, forming a sound transmission angle between the first and second sound transmission channels. The first sound transmission channel is connected to the inlet of the sound transmitting element, and the second sound transmission channel is connected to the outlet of the sound transmitting element. The sound receiving element is connected to the sound transmitting element and has a sound receiving port that is connected to the outlet of the sound transmitting element. When sound enters the sound transmitting element, it passes through the first and second sound transmission channels in sequence. The first and second sound transmission channels intersect each other, which attenuates and blocks high-frequency noise signals in the sound signal, thus reducing the high-frequency noise in the incoming sound and effectively improving the noise reduction capability against external noise.

The application provides a fresh air device and an air conditioner, wherein the fresh air device comprises: a volute, a first shell which forms a cavity together with the volute, the first shell being provided with an air inlet which is in communication with the cavity; and a second shell which is located on the side of the first shell away from the volute and forms a second sound absorption cavity together with the first shell; wherein the first shell is provided with a plurality of first through holes which are used for communicating the cavity and the second sound absorption cavity. By forming the second sound absorption cavity on the side of the first shell away from the volute and communicating the cavity and the second sound absorption cavity through the first through holes, the second sound absorption cavity can absorb low-frequency noise, the noise attenuation capability can be improved, and the mute performance can be improved.

The utility model discloses a multifunctional composite breathing film, a heat insulation assembly, a battery module and a battery pack, the multifunctional composite breathing film comprises a phase change layer and a heat insulation packaging film wrapping the phase change layer, and a temperature sensing viscous coating is arranged on the outer surface of the heat insulation packaging film; the phase change layer is in a liquid state within the working temperature range of the battery cell, and the viscosity of the temperature-sensitive viscous coating is gradually weakened along with the rise of the temperature. According to the multifunctional composite breathing film provided by the utility model, the outer temperature sensing viscous coating is bonded with the battery cell, the inner phase change layer can completely meet the ballooning caused by a large surface when the battery cell is charged and discharged, and the breathing film can be automatically adjusted according to the ballooning degrees of different areas on the large surface of the battery cell; therefore, the large surface of the whole battery cell is under the same pre-tightening pressure, the attenuation of the battery cell is improved, and the cycle life of a battery pack is greatly prolonged. Meanwhile, the heat insulation packaging film has excellent heat insulation blocking performance, and heat spreading of the thermal runaway battery cell can be effectively isolated.

The application relates to the technical field of alloy coating materials, and particularly discloses a high-pressure hot-pressing die oxidation-resistant coating and a preparation method thereof. The high-pressure hot-pressing die oxidation-resistant coating comprises a transition layer and a functional layer arranged outward from a die base body, the transition layer is a TiN-SiC gradient composite layer, the functional layer takes Al2O3-NiCrAlY as a base body, and is compounded and doped with double-modified nano ZrB2 and rare earth CeO2; the double-modified nano ZrB2 is ZrB2 particles coated with a silane coupling agent KH-560 and a NiCr alloy. The high-pressure hot-pressing die oxidation-resistant coating has oxidation resistance and wear resistance, and effectively enhances the high-temperature hardness stability and wear resistance of the oxidation-resistant coating.

This invention relates to the field of microwave absorbing materials technology, specifically to an iron-cobalt alloy carbon magnetoelectric composite microwave absorbing material, its preparation method, and its applications. The specific preparation method includes the following steps: using potassium ferricyanide as the carbon and nitrogen source, a co-precipitation reaction is carried out with a Co source and sodium citrate in a solvent system to prepare a Prussian blue analog; then, under a protective atmosphere, the Prussian blue analog is pyrolyzed at 400–600℃, causing Co nanoparticles to be loaded onto the surface of a carbon-nitrogen matrix, resulting in the iron-cobalt alloy carbon magnetoelectric composite microwave absorbing material. This invention mainly uses the C≡N groups in the metal coordination bonds as the carbon and nitrogen sources, and Co nanoparticles as magnetic particles. By controlling the pyrolysis temperature, the microstructure and internal structure of the product are altered, thereby controlling the electromagnetic parameters of the material and obtaining an absorbing material with good impedance matching and attenuation performance.

The utility model relates to a silent foaming device which comprises a rod body provided with a spray hole. The spraying holes are connected with a steam source; the first supporting part is connected with the rod body; around the axis of the rod body, the outer contour of the first supporting part exceeds the outer contour of the rod body; the barrel body is arranged on the rod body in a sleeving manner; the first supporting part is in contact with the inner wall of the barrel and supports the barrel; a cavity is formed between the barrel body and the rod body; a through hole is formed in the barrel and communicated with the cavity; the second supporting part is arranged in the cavity; wherein the first supporting part is connected with the cylinder body in a sealing manner; and the orifice of the spraying hole is formed in one side, far away from the first supporting part, of the second supporting part. Through the cooperation of the first supporting part and the second supporting part, the position relation between the rod body and the barrel body is fixed in a multi-point mode, the stability of the rod body is improved, noise generated by mechanical vibration of the rod body is reduced, and the use experience of a user is optimized.