30results about How to "Reduced stress state" patented technology

The invention discloses a preparation method of a low stress state composite substrate for GaN growth. The preparation method comprises that a GaN monocrystal epitaxial layer is prepared on a sapphire substrate; a stress compensation layer is deposited at the back side of a thermally and electrically conductive transfer substrate of high welding point; bonding dielectric layers of high welding point are prepared at the surfaces of a GaN epitaxial wafer and the transfer substrate respectively; the GaN epitaxial wafer is bonded to the thermally and electrically conductive substrate by the high-temperature diffusion bonding technology; and the composite substrate with high temperature stability and low stress state for GaN growth is obtained. According to the composite substrate of the invention, homoepitaxy can be realized and a vertical structural device can be directly prepared as a traditional composite substrate, the low stress state and high-temperature stability can be also realized, and the quality of subsequent GaN epitaxial growth and chip preparation can be effectively improved.

The present invention provides a reinforcing method for treating the concrete and masonry structural crack, according to the concrete condition of the crack, a self-pressure crack processor or air compressor is adopted for assorting the pressure generated by equipments of a slurry storing pot and the like, the corresponding grouting material is pressed into the existing crack, after the hardening of the grouting agent the concrete or masonry at the two sides of the crack can be adhered from the inner side namely inner adhering; the high-technique materials of FRP board, sheet material, rod material and the like or the ordinary materials of reinforcing steel bar, steel plate and the like is selected for adhering across the crack or a groove is cut for anchoring, the concrete at the two sides of the crack is connected from the outside namely exterior cramping. The adopting of the method can thoroughly settle the problem of the building structural crack.

The invention provides a preparation method of a fine grain copper alloy shaped charge liner. The preparation method of the fine grain copper alloy shaped charge liner comprises the following steps: carrying out compound cold extrusion plastic deformation, carrying out deep overcooling treatment, and carrying out recrystalization annealing, wherein the compound cold extrusion plastic deformation comprises the steps of putting a blank into a mould cavity of a preformed blank forming mould, carrying out forward extrusion forming to obtain a designed copper alloy preformed blank under the actions of three-dimensional compressive stress and deformation rate and then putting the preformed blank into a mould cavity of a shaped charge liner forming mould and gradually forming the shaped charge liner preformed blank by carrying out gradual-pass diameter-expanded extrusion plastic deformation, thus obtaining the shaped charge liner blank of a required shape structure; the deep overcooling treatment comprises the step of carrying out heat preservation on the shaped charged liner blank for 2-4 hours at the temperature ranging from -196 DEG C to 130 DEG C; and the recrystallization annealing comprises the step of carrying out heat preservation on the shaped charge liner (subjected to deep overcooling treatment) for 5-15 minutes at the temperature of 450-550 DEG C in a protective atmosphere, thus obtaining a shaped charge liner component. The preparation method of the fine grain copper alloy shaped charge liner has the advantages that strict requirements of the shaped charge liner on grain structure homogeneity, consistency of performance and stress state and distribution can be met, and quality of the shaped charge liner can be improved.

The invention is directed to a method and apparatus for relieving stress using biofeedback techniques. In embodiments, the method and system are used according to a specified regimen to enable a user to achieve a relaxed state. The apparatus comprises a sensor 10 wirelessly connected to a CPU 20, which processes signals from the sensor 10 to produce a visual display 36 and/or auditory display 44 that is representative of the relaxation state of the user.

The invention relates to a rotor blade (20), especially for a rotary wing aircraft. The invention is characterized in that an aerodynamically effective rotor blade profile with a profile nose region (21), a profile base body (20a) with a profile core, an upper and lower cover skin (30) that envelops the profile core (22), and a profile rear edge region (23) with a rear edge (40) and a reversibly bendable supporting member (26) that can be attached with the first end to the end region of the profile base body (20a) pointing toward the rear edge (40) and projects with the second end freely out of the profile base body (20a) and its end region toward the rear edge (40) and forms a movable rotor blade flap (24), and several actuators (35) that are dynamically connected to the projecting second end of the reversibly bendable supporting member (26) and an arc-shaped flap deflection can be initiated via the change in length of the actuators, the second end of the reversibly bendable supporting member (26) that forms the rotor blade flap (24) viewed in the direction of the span (S) being divided by notches (34) into several segments to which at least one actuator (35) at a time is assigned.

The invention discloses a fabricated self-resetting concrete frame soft steel energy dissipation composite joint. The fabricated self-resetting concrete frame soft steel energy dissipation composite joint includes a prefabricated reinforced concrete column, a prefabricated reinforced concrete beam, soft steel dampers, a pre-stressed steel strand, embedded high-strength bolts and anchored steel bars, wherein the prefabricated reinforced concrete beam is provided with a beam end embedded steel sleeve, and a column end embedded steel plate is arranged at the butt-joint position between the prefabricated reinforced concrete column and the beam end embedded steel sleeve; the pre-stressed steel strand penetrates through a pre-stressed steel strand hole channel of the prefabricated reinforced concrete column, a pre-stressed steel strand opening of the column end embedded steel plate, a pre-stressed steel strand opening of the beam end embedded steel sleeve and the pre-stressed steel strand channel of the prefabricated reinforced concrete beam in sequence, so that the prefabricated reinforced concrete column and the prefabricated reinforced concrete beam are spliced together; and the soft steel dampers are arranged on both sides of a web plate of the section steel part of the beam end embedded steel sleeve. The fabricated self-resetting concrete frame soft steel energy dissipation composite joint enables the prefabricated concrete frame structure to have excellent seismic performance and self-resetting ability under high earthquake intensity.

Method for applying a reinforced composite material, such as a fibre reinforced polymer (FRP) laminate or a steel reinforced polymer (SRP) laminate or a steel reinforced grout (SRG) composite, to a structural member. The method comprises the steps of: applying a curable adhesive to a surface of the structural member and/or a surface of the reinforced composite material, and bringing said surfaces into contact. A pre-stressing force, P_max, is directly or indirectly applied to the reinforced composite material. The pre-stressing force, P_max, to which a treatment length, L_T, of the reinforced composite material is subjected is then decreased so that the reinforced composite material along the treatment length, L_T, will be less pre-stressed than the reinforced composite material adjacent to the treatment length, L_T, when the adhesive has cured.

The invention relates to a multistage sealing anti-sticky buckle type thread for a titanium alloy oil casing. The multistage sealing anti-sticky buckle type thread comprises an oil casing coupling and an oil casing tube end, the oil casing coupling is provided with a standard API buttress internal thread which is sequentially connected with a tool withdrawal groove, a cone surface to cone surface first stage sealing structure, a cylinder surface to cylinder surface second stage sealing structure and a negative angle torque circular bead, wherein the cone surface to cone surface first stage sealing structure and the cylinder surface to cylinder surface second stage sealing structure are in transition through chambering, and the negative angle torque circular bead is connected with the standard API buttress internal thread through a transitional angle. The multistage sealing anti-sticky buckle type thread for the titanium alloy oil casing has the advantages that two stages of metal sealing and one negative angle torque circular bead sealing are added based on the improved buttress thread, the reliability of the air tightness of a thread connector is improved through the design of multistage sealing, meanwhile, the stress state of the thread connector is reduced by changing a thread parameter, the performance of an anti-sticky buckle is improved, and machining and detecting are convenient.

The present invention relates to the field of coal mining technology, in particular to a method for retaining roadways along gobs, comprising the following steps: S1, excavating a first roadway on the side adjacent to the second mining face on the first mining face, The roadway is supported, and at the same time, the side of the first roadway close to the second mining face is prefabricated; S2, before the mining of the first mining face, the roof of the first mining face is prefabricated with cracks; S3, at the Excavate the second roadway on the side near the side of the roadway on the secondary mining face, and support the second roadway. The invention solves the problems of high pressure, high stress and serious deformation of the concrete wall in the commonly used gob-side retaining roadway. During the excavation of the previous working face, the concrete wall of the gob-side retaining is prefabricated in advance, and the process during the mining of the working face is reduced. The degree of complexity increases the recovery speed of the previous working face, and the secondary roadway of gobside retaining often needs to be repaired, which requires a large amount of work and high difficulty. The present invention is a new roadway for the next working face, so there is no need for roadway repair.

An increased resilience seal utilizing a sealed gas filled inner chamber in a bellows spring that functions as both a mechanical spring and a gas spring to provide a more constant level of separation force between two face plates to provide a seal between two mechanical components such as those found in an aircraft jet engine. The bellows spring is made of a plurality of walls that are joined together in a pressurized chamber that is filled with a gas, such as an inert gas. In alternative embodiments, the bellows spring is made of walls that are shaped and oriented to optimize the operating characteristics of the bellows spring when the pressure is increased in a sealed inner chamber in response to elevated temperature. In one embodiment, the walls forming a portion of the chamber overlap to optimize the geometry of the bellows spring.

Methods and systems for reducing the stress state of compressed ends of compressed tubes are disclosed. The methods and systems may provide a reduced tensile residual stress state, or even a compressive residual stress state. Tube products produced from the same are also provided.

The invention belongs to the technical field of injection forming and relates to a method for manufacturing a variable-thickness structural transparent workpiece, and particularly relates to a method for manufacturing a high-accuracy variable-thickness cambered transparent workpiece. The method disclosed by the invention carries out forming processing on a variable-thickness workpiece by adopting a primary integral injection compression and secondary differential expansion injection compression combined injection forming method, thereby effectively controlling the surface quality and retracting warpage of the workpiece in areas with different thicknesses; in addition, the method disclosed by the invention carries out forming by selecting a polycarbonate material with excellent impact resistant property, thereby ensuring the characteristics of light weight and transparency of the workpiece. According to the method, the mould temperature is controlled to be higher than plastic glass transition temperature in a stage of filling a cavity through a fusant by applying a dynamic variable-mould temperature control technology, and after expansion and compression are finished, the mould temperature is fast reduced to sufficiently cool a shaped workpiece, so that the surface quality of the workpiece is ensured, the forming period is shortened, and the production cost is reduced. The workpiece manufactured by adopting the method disclosed by the invention can achieve the light transmittance of more than 75%, and the optical distortion of an effective area can be controlled to be less than 1/10.

A control unit for an equipment arrangement is provided. The control unit includes an imaging modality, a measurement device for measuring a control variable and a controllable injection device for a regulatory substance influencing the control variable, wherein the injection rate of the injection device may be varied during a data acquisition such that a proposed value for the control variable is reached.

The invention discloses a stress relieving device for a thin-wall cylindrical part. The stress relieving device comprises a placement block, wherein a first transmission cavity is formed in the placement block; a radial fixing mechanism is arranged in the first transmission cavity; and the radial fixing mechanism comprises a driving motor which is fixedly arranged on the inner wall of the rear side of the first transmission cavity. According to the stress relieving device disclosed by the invention, the thin-wall cylindrical part is radially fixed through a clamping block and an inflation pushing silica gel strip, so that clamping processing is convenient, and the problem of instability and deformation is completely avoided; and meanwhile, a method for relieving stress by cold and hot alternation is adopted for the thin-wall cylindrical part through a high-temperature pipe and a low-temperature pipe, so that the thin-wall cylindrical part generates pressure stress or tensile stress under continuous cold and hot alternation, the pressure stress or the tensile stress is counteracted with machining stress, the stress state of the part is reduced, the problems of large residual stress, easiness in deformation and the like in a processing process of the thin-wall cylindrical part are effectively solved, and the processing reliability and the product quality of the thin-wall cylindrical part are improved.