84results about How to "Easy modular assembly" patented technology

Modular aAPCs and methods of their manufacture and use are provided. The modular aAPCs are constructed from polymeric microparticles. The aAPCs include encapsulated cytokines and coupling agents which modularly couple functional elements including T cell receptor activators, co-stimulatory molecules and adhesion molecules to the particle. The ability of these aAPCs to release cytokines in a controlled manner, coupled with their modular nature and ease of ligand attachment, results in an ideal, tunable APC capable of stimulating and expanding primary T cells.

Polymeric nanoparticles encapsulating inhibitory ribonucleic acids (RNAs) and methods of their manufacture and use are provided. Advantageous properties of the nanoparticles include: 1) high encapsulation efficiency of inhibitory RNAs into the nanoparticles, 2) small size of the nanoparticles that increases cell internalization, and 3) sustained release of encapsulated inhibitory RNAs by the nanoparticles that allows for administration of an effective amount of inhibitory RNAs to cells or tissues over extended periods of time. Encapsulation efficiency of inhibitory RNAs into the nanoparticles is greatly increased by complexing the inhibitory RNAs to polycations prior to encapsulation. Methods of using the polymeric nanoparticles for treating or inhibiting diseases or disorders are provided.

The invention aims to provide an automobile wiring harness protective sleeve convenient for vehicle door wiring harness installation and later period maintenance. The automobile wiring harness protective sleeve comprises a hollow tubular main body (1), tubular fixed parts (2) and (3) are arranged at both ends of the main body (1), an annular groove (21) is arranged on the outer surface of the tubular body of the fixed part (2), and an annular groove (31) is arranged on the inner surface of the tubular body of the fixed part (3). The automobile wiring harness protective sleeve enables the butted point between the vehicle door wiring harness and the main wiring harness in the vehicle body to be transferred to the sheet metal hole from the inside of the vehicle body, thereby greatly simplifying the assembly procedures and facilitating the modular assembly of the vehicle door and the later period maintenance, and the automobile wiring harness protective sleeve has simple structure and low cost and is suitable for being widely popularized.

The invention discloses a side wall structure for a hopper car. The side wall structure comprises an integrally formed upper side beam (1), an integrated side wall plate (2), an integrally formed lower side beam (3) and a lower side wall (4). The upper side beam (1) and the integrated side wall plate (2) below are riveted. The side wall plate (2) and the integrally formed lower side beam (3) below are riveted. The side wall plate is in a wall plate and side column integrated plate-column structure, and the side columns are arranged on the inner side of the car body. The lower side beam (3) and the lower side wall (4) below are riveted. According to the side wall structure, by means of the integrated side wall plate with the built-in side columns, both the strength reduction due to rivet holes and the increased weight and cost due to the usage of rivets are prevented, the side columns are arranged inside, so that space among the side columns is used, and the car body volume is increased.

The invention relates to the fields of marine environment monitoring and optical-fiber sensing technology, and particularly to a marine multi-parameter integrated monitoring system based on a micro-nano optical-fiber half coupler and a method. The monitoring system includes a tunable wavelength scanning light source, an optical-fiber isolator, a 1x4 tunable optical switch, a CTD sensor, a magnetic-field sensor, a humidity sensor ,a harmful-gas sensor, a photodetector No.1, a photodetector No.2, a photodetector No.3, a photodetector No.4, a collection card and a signal processing computer. Thesystem of the invention has the advantages of a simple structure, low costs, high sensitivity, multi-parameter integrated sensing, high integration, convenient deployment, high data compatibility andthe like, and effectively satisfies multi-parameter integrated monitoring and information processing application demand of marine environments. The system is an optical-fiber sensing system, can be convenient for integration with an existing optical-fiber hydrophone system, and then provides a real-time in-situ high-precision marine dynamic environment guarantee.

The invention relates to a vertical tuned mass magnetic lead screw type inerter eddy current damper. The vertical tuned mass magnetic lead screw type inerter eddy current damper comprises a spring mass system, an inertia mass system, an eddy current damping system and a supporting system; the spring mass system comprises a spring and a clump weight; the inertia mass system comprises a flywheel, amagnetic lead screw nut pair and a magnetic suspension thrust bearing; the eddy current damping system comprises a straight-strip-shaped permanent magnet, a conductor plate and back iron; and the supporting system comprises guide rods, a supporting bracket and an outer frame. According to the damper, the inerter principle is introduced, physical balance weight is reduced, the net elongation of thespring of a low-frequency structure controlled by the device is reduced while the mass ratio of the device is increased; by adopting the magnetic lead screw nut pair, the friction between a lead screw and a nut is eliminated, and the working efficiency is improved; meanwhile, the magnetic suspension thrust bearing is used cooperatively to ensure that the flywheel is suspended in a flywheel chamber to work normally; and the overall friction of the damper is greatly reduced, and the service life is prolonged.

The invention discloses an assembling and shaping fixture for a vehicle-mounted battery pack system module. The fixture comprises a bearing assembly, a pair of shaping assemblies and fixing assemblies, wherein the bearing assembly comprises a module assembling tray fixed on any fixture platform, and a pair of limiting baffle blocks arranged on the module assembling tray in parallel, and an accommodating area which is used for placing a battery pack is formed between the limiting baffle blocks; the pair of the shaping assemblies is respectively arranged at the two ends, without the limiting baffle blocks, of the accommodating area, and the pair of the shaping assemblies is respectively equipped with shaping pushing plates which can oppositely or reversely move along a direction parallel to the axial direction of the limiting baffle blocks; each fixing assembly comprises a steel belt bundled on the battery pack and a steel belt tightening mechanism connected with the steel belt. According to the invention, the bearing assembly is used for limiting a plurality of battery cells, the shaping assemblies are used for trimming the battery pack, and the fixing assemblies are used for fixing the size and the dimension of the battery pack, so that modularized assembling for the battery cells is conveniently completed with high stability and reliability, and thus, the production efficiency is improved.

The invention discloses a broadband electromagnetic wave absorption super material based on fusion of a foam medium-based material and a metal structure, and belongs to the technical field of electromagnetic wave absorption. The super material is composed of foam materials with different shapes and pore diameters and metal structures with different structural sizes. The combined metamaterial structure utilizes the advantages of light foam materials, large scattering loss, strong interface polarization loss and low impedance, and fully utilizes the flexible and controllable characteristics of the absorbing frequency band of the metal metamaterial structure so that the maximum flat reflectance of the metamaterial in the whole frequency range of 1-18 GHz is reduced to below 10 dB, and the flat panel reflectance of the key frequency band is reduced to below 15 dB, the surface density is less than 8kg / m2, and the super material has a good broadband electromagnetic wave absorption performance. The super material can achieve wide-band radar stealth, can solve the problems of narrow bands, large thickness and high surface density of the absorbing materials in the prior art, and achieves effective electromagnetic wave absorption.

The invention discloses an anti-abrasion denitration catalyst and a preparation method thereof. The preparation method comprises the following steps of dissolving titanium source precursors into acid to form a solution; respectively dissolving molybdenum source precursors, phosphorus source precursors and magnesium source precursors to form solutions; uniformly mixing the solutions; regulating the pH value; performing precipitation, filtering and washing; then adding deionized water; preparing the materials into slurry; adding a vanadium source precursor solution; after uniform mixing, directly performing drying and roasting; grinding the materials into powder; next, adding extrusion auxiliary agents, a solution formed by the molybdenum source precursors and pore forming agents; adding water during the stirring to obtain paste; regulating the pH value; adding nanometer silicon dioxide, wollastonite, glass fiber and bonding agents; performing uniform mixing; extruding honeycomb-shaped blanks by an extruding machine; performing drying and roasting; then, obtaining a finished product. The prepared anti-abrasion denitration catalyst can overcome the defects of unstable activity, poor anti-abrasion performance and activity center unbalance of a denitration catalyst in flue gas in the prior art.

The invention provides a crimp connection type IGBT internal package structure encapsulated in a ceramic tube casing. The structure comprises an IGBT / FRD chip and silicon carbide aluminum layers. Thesilicon carbide aluminum layers are located on the upper and lower sides of the IGBT / FRD chip. A soldering layer is arranged between the IGBT / FRD chip and each of the silicon carbide aluminum layers,and the upper and lower surfaces of the IGBT / FRD chip are provided with metal layers. The invention provides a silicon carbide aluminum-soldering layer-IGBT / FRD chip-welding layer-silicon carbide aluminum internal structure of a ceramic shell packaged crimp connection type IGBT, so the packaging process operation of the ceramic shell packaged crimp connection type IGBT is greatly simplified; double-sided heat dissipation of the crimp connection type IGBT is ensured; and requirement of high current flow and high reliability are met.

The invention provides a spiral flow hot water air heating water tank, and belongs to the technical field of solar energy. The spiral flow hot water air heating water tank can use waster hot water such as solar energy hot water and recycled shower water to heat air, obtain hot air flow with sufficiently high temperature and high speed and be widely used in occasions such as heating, ventilation, warming, drying and pushing. Heat exchange and flow of the hot water and the air are both in a fully natural passive mode. The water tank can be applied in a unit mode and a scale combined mode. The unit and combined water tank comprises a heating speed increasing section and an introduction and eduction section. The heating speed increasing section comprises an inner ring water tank, an outer ring water tank and an air interlayer which are all formed by enclosing cylinder wall faces which are arranged inside and outside according to a common center axis. Due to the fact that laminated hole staggered horizontal pore plates are arranged on the inner ring water tank and the outer ring water tank, a channel of the air interlayer is narrow and small, staggered hole transverse cylinder pore wall is arranged in the channel of the air interlayer, natural spiral flow of the hot water and the air is formed, and strong heat exchange and strong speed increasing which are attached to the wall and spirally convective are achieved. An inner ring wall and an outer ring wall of the air interlayer adopt metal materials with good heat-conducting property, and other enclosing wall surfaces can adopt materials which are cheap and easy to machine such as plastics.

The invention provides a ball screw type eddy current damper with a negative-stiffness nonlinear energy trap. The ball screw type eddy current damper comprises an outer frame, a vertically-arranged guide rod, a supporting frame, a mass block, a spring, an alternate permanent magnet set, a conductor plate and an iron plate, wherein a set gap is reserved between the alternate permanent magnet set and the conductor plate. The damper further comprises a vertically-arranged ball screw, a nut, a flywheel and a thrust bearing. The damper further comprises a homonymous permanent magnet set and / or a synonymous permanent magnet set which can generate the negative-stiffness nonlinear energy trap effect. When vibration energy of a controlled structure is transmitted to the damper, the mass block is caused to vibrate up and down, the homonymous permanent magnet set and / or the synonymous permanent magnet set capture / captures resonance energy within a wide frequency range, the ball screw drives theflywheel to rotate at a high speed to generate the inertia mass effect, the conductor plate cuts magnetic induction lines of the alternate permanent magnet set, and the eddy current damping effect isformed; and back iron can reduce magnetic flux leakage and improve the damping energy consumption efficiency.

Polymeric nanoparticles encapsulating inhibitory ribonucleic acids (RNAs) and methods of their manufacture and use are provided. Advantageous properties of the nanoparticles include: 1) high encapsulation efficiency of inhibitory RNAs into the nanoparticles, 2) small size of the nanoparticles that increases cell internalization, and 3) sustained release of encapsulated inhibitory RNAs by the nanoparticles that allows for administration of an effective amount of inhibitory RNAs to cells or tissues over extended periods of time. Encapsulation efficiency of inhibitory RNAs into the nanoparticles is greatly increased by complexing the inhibitory RNAs to polycations prior to encapsulation. Methods of using the polymeric nanoparticles for treating or inhibiting diseases or disorders are provided.

The invention discloses an antiwear honeycomb type denitration catalyst for reducing the SO2 oxidation rate and a preparation method thereof. The preparation method comprises the following steps that a titanium source precursor is dissolved in acid to form a solution; a molybdenum source precursor, a phosphorus source precursor and a magnesium source precursor are respectively dissolved to form solutions; the solutions are uniformly mixed; the pH value is regulated; precipitation and filtering are performed; then, deionized water and a vanadium source precursor solution are added; after being uniformly mixed, the mixture is directly dried, roasted and ground into powder; an extrusion aid and a solution formed by the molybdenum source precursor and a pore-forming agent are added into the powder; water is added while the stirring is performed until the paste shape is formed; then, nano-silicon dioxide, wollastonite, glass fiber and an adhesion agent are added and are uniformly mixed; a honeycomb type blank is extruded by an extruder; the dried blank is firstly put into a silicon source precursor solution to be soaked; after roasting, the finished product is obtained. The defects of active instability, poorer antiwear performance and unbalanced active center of the denitration catalyst in the flue gas in the prior art can be overcome.

The invention discloses a horizontal spent fuel storage module for a nuclear power plant. A lower-layer structure of the horizontal spent fuel storage module comprises N lower-layer modules which areindependent of one another and are arranged side by side, and an upper-layer structure comprises N-1 upper-layer modules which are arranged side by side and are staggered with the lower-layer modules;main bodies of the upper-layer modules and the lower-layer modules are of hollow cuboid structures; a bottom plate of the upper-layer module clings to a top cover of the lower-layer module; an upper-layer module air inlet is formed in the middle of a bottom plate of the upper-layer module, first meshing plates nested into the upper-layer module air inlet are arranged on the two sides of a top cover of the lower-layer module respectively, a lower-layer module air outlet is formed in the middle of a top cover of the lower-layer module, and second meshing plates nested into the lower-layer module air outlet are arranged on the two sides of the bottom plate of the upper-layer module respectively. A Z-shaped meshing structure is formed between the bottom plate of the upper-layer module and thetop cover of the lower-layer module, and each upper-layer module is meshed and fixed on two adjacent lower-layer modules to form a staggered structure. The horizontal spent fuel storage module has the advantages of being good in stability, easy and convenient to assemble in a modular mode and small in occupied area.

The invention relates to a heat exchange device of a hydrogen catalytic combustor, and belongs to the technical field of hydrogen catalytic combustion. The heat exchange device of the hydrogen catalytic combustor is characterized by comprising a heat exchange tank and a heat exchange tube, wherein the hydrogen catalytic combustor is arranged inside the heat exchange tank, the heat exchange tube is installed at an outlet of the hydrogen catalytic combustor, heat exchange medium is arranged inside the heat exchange tube, and the heat exchange tube is located inside the heat exchange medium. The heat exchange device of the hydrogen catalytic combustor has the advantages of being high in heat exchange efficiency, good in heat output stability, simple to manufacture, low in cost, convenient to use, good in safety, capable of being assembled in a modularized mode conveniently, being high in heat utilization rate of hydrogen catalytic combustion, and the like.

The invention discloses an ultrasonic array interaction method and system fusing visual tactile perception. The method comprises the steps: collecting hand posture information, and calculating fingertip coordinates of a finger to form a position array; for the palm, calculating palm center coordinates and palm surface normal vector parameters to form a vector array; if the finger is detected, selecting to activate the ultrasonic array based on the distance according to the position array; if the palm is detected, starting a motion platform based on directivity selection according to the fingerposition array and the palm vector array, activating a corresponding ultrasonic array after the platform is parallel to the palm, and returning angle information; adopting focus information after homogeneous coordinate transformation to drive a transducer to emit ultrasonic waves to generate a focus point to form tactile feedback, and displaying the focus point, a virtual hand and surrounding scene information in real time, and completing visual tactile fusion perception. Multi-angle different forms of tactile feedback are provided for fingers and palms, the feeling is finer and more vivid, visual perception is fused, the interaction experience is enriched, and the interaction accuracy is improved.

The invention belongs to the technical field of vehicle wheels, and particularly relates to a driving integrated type integral wheel which comprises a motor module, an inner gear speed reduction module and a wheel module in sequential connection. The inner gear speed reduction module comprises a motor installing base and a speed reduction module shell base matched with the motor installing base. The inner gear speed reduction module is detachably connected with the motor module through the motor installing base. The inner gear speed reduction module is connected with the wheel module through the speed reduction module shell base. By installing the inner gear speed reduction module into a sunk tire, the axial installing size of the whole driving wheel is reduced, and the driving wheel is more compact in structure; the motor module, the inner gear speed reduction module and the wheel module are detachably connected, and modularized production and assembly are facilitated.

The invention discloses a honeycomb-type vanadium-free denitrification catalyst for reducing the SO2 oxidation rate and a preparation method thereof. The preparation method comprises the following steps that a titanium source precursor is dissolved in acid to form a solution; a tungsten source precursor, a phosphorus source precursor and a magnesium source precursor are respectively dissolved to form a solution; the solutions are evenly mixed, a pH value is regulated to 7-12, precipitation and filtration are performed, then deionized water and a rare earth precursor solution are added, drying and calcination are performed directly after even mixing, and the mixture is grinded into powder; a solution prepared by an extrusion additive and the tungsten source precursor and a pore forming agent are added in the powder, water is added while stirring to form paste, then nano silica, glass fiber and a binder are added and are evenly mixed, and a honeycomb-type blank is extruded out by utilizing an extruding machine; the dried blank is firstly put in a silicon source precursor solution for impregnation, and a finished product is obtained after calcination. The prepared honeycomb-type vanadium-free denitrification catalyst overcomes the defects of active center imbalance and unstable activity of a denitrification catalyst in flue gas in the prior art.

The invention discloses a pedal simulation device which comprises a simulator cylinder, an oil inlet control valve and a normally open control valve, and is characterized in that the oil inlet controlvalve and the normally open control valve are arranged on an end cover of the simulator cylinder; a port a of the oil inlet control valve and a port a of the normally open control valve are communicated with a brake master cylinder; a port b of the oil inlet control valve is communicated with the simulator cylinder; a port b of the normally open control valve is communicated with a brake actuator; a one-way valve is arranged between the port a and the port b of the oil inlet control valve; a hydraulic sensor is arranged on the end cover of the simulator cylinder; and the hydraulic sensor is arranged in an oil way of the normally open control valve and the brake master cylinder and connected with an ECU (Electronic Control Unit). According to the pedal simulation device disclosed by the invention, the simulator cylinder, a solenoid valve and the hydraulic sensor are integrated onto the end cover of the simulator cylinder, modular assembly of the product is facilitated, risk of pipelinejoint leakage is reduced, and the safety and reliability of the product are improved.

The invention discloses a food processor with low noise. The food processor comprises a machine seat provided with a motor, a stirring cup connected with the machine seat and a grinding cutter arranged in the stirring cup; the upper end of the motor shaft of the motor is connected with the grinding cutter, the machine seat is provided with an air inlet and an air outlet, and the air outlet is located on one side of the lower part of the machine seat; and a heat dissipation air flue communicated with the air inlet is defined by the machine seat, a fan is arranged at the lower end of the motor shaft, a volute communicated with the heat dissipation air flue is arranged at the bottom of the machine seat, the volute is arranged at the periphery of the fan, a ventilation curve is arranged between the volute and the air outlet, wherein the arc length of the ventilation curve is L1, the arc length of the volute is L2, and the value of L1 / L2 is higher than or equal to 0.5 and lower than or equal to 2. The food processor can effectively lower the noise, and thereby improving the user experience.

The invention provides a water supply system for a drug spraying unmanned aerial vehicle. The water supply system for the drug spraying unmanned aerial vehicle is characterized in that the water supply system comprises a busbar and a peristaltic pump assembly, wherein the peristaltic pump assembly comprises motors, pump heads and a converter; the forward and reverse rotation of the motors are controlled to drive the different pump heads through a drive shaft in the converter and two one-way bearings mounted on both end heads of the drive shaft, wherein the two one-way bearings drive in opposite directions; the pump heads supply water for four nozzles through the busbar; when the two motors are rotating forward, the two pump heads are driven under the action of the one-way bearings; after the pump heads take water from a main passage through a water supply passage, the water is sent into a water outlet passage through a water passage, thereby realizing double nozzle water spray; when the two motors rotate in reverse, the other two nozzles are controlled to spray water. The water supply system for the drug spraying unmanned aerial vehicle has the advantages of guaranteeing compact structure, stable operation and low cost with a one-way valve to make the motors rotate forward and reverse so as to run the two pump heads separately, allowing the layout of each passage of the busbarto be ingenious and compact, and facilitating easy modular assembly after the the peristaltic pump assembly is mounted.

The present invention discloses a SO2 oxidation rate reducing honeycomb type vanadium-free flue gas denitration catalyst and a preparation method thereof. The preparation method comprises: dissolving a titanium source precursor in an acid to form a solution; dissolving a tungsten source precursor to form a solution; uniformly mixing the two solutions, adjusting the pH value to 7-12, precipitating, filtering, adding deionized water and a rare earth precursor solution, uniformly mixing, directly drying, roasting, and grinding to obtain powder; adding the solution formed from an extrusion aid and the tungsten source precursor and a pore forming agent to the powder, adding water while stirring to form a paste, adding nano-silica, glass fiber and a binder, uniformly mixing, and extruding a honeycomb type billet by using an extruder; and placing the dried billet into a silicon source precursor solution, impregnating, and roasting to obtain the finished product. According to the present invention, the defects of unbalanced activity center, poor molding property and unstable activity of the denitration catalyst in the flue gas in the prior art can be overcome.

The invention discloses an installing worktable for cabinet bodies. The installing worktable comprises a table top; the upper part of the table top is glidingly provided with a first sliding plate anda second sliding plate; the first sliding plate and the second sliding plate are symmetrically arranged about the center line of the table top; the upper plane of the first sliding plate and the upper plane of the second sliding plate are respectively provided with a fixing plate used for fixing electrical cabinets; the lower part of the table top is symmetrically provided with tool boxes; the side face of each tool box is provided with a push rod; and the lower part of the table top is also connected with support legs with rollers through racks. The worktable is capable of realizing initialinstallation and transfer function of the cabinet bodies, is suitable for the cabinet bodies of various type specifications, and is simple to operate, safe and reliable.

The invention discloses a honeycomb type flue gas denitrification catalyst and a preparation method thereof. The preparation method comprises the following steps: dissolving a titanium source precursor into acid, so as to form a solution; respectively dissolving a tungsten source precursor so as to form a solution; uniformly mixing the two solutions, adjusting the pH value of a mixed solution, settling, washing, and filtering so as to obtain a filter cake; blending to form slurry, adding a vanadium source precursor solution, uniformly mixing, directly drying and roasting, and grinding into powder; adding an extruding aid, the phosphorus source precursor solution and a pore forming agent into the powder, adjusting the pH value to be alkaline, adding nano-silica, glass fibers and a bonding agent, uniformly mixing, and extruding a honeycomb type blank by virtue of an extruding machine; and drying and roasting, so as to obtain a finished product. The honeycomb type flue gas denitrification catalyst prepared by virtue of the preparation method is capable of resisting heavy metal deposition in flue gas and simultaneously has high catalytic performance and low sulfur dioxide / sulfur trioxide conversion rate.

Polymeric nanoparticles encapsulating inhibitory ribonucleic acids (RNAs) and methods of their manufacture and use are provided. Advantageous properties of the nanoparticles include: 1) high encapsulation efficiency of inhibitory RNAs into the nano articles, 2) small size of the nanoparticles that increases cell internalization, and 3) sustained release of encapsulated inhibitory RNAs by the nanoparticles that allows for administration of an effective amount of inhibitory RNAs to cells or tissues over extended periods of time. Encapsulation efficiency of inhibitory RNAs into the nanoparticles is greatly increased by complexing the inhibitory RNAs to polycations prior to encapsulation. Methods of using the polymeric nanoparticles for treating or inhibiting diseases or disorders are provided.

The invention discloses a laminar flow purifying unit for a modular ceiling of a clean room and belongs to the technical field of an operating room air conditioning system. The laminar flow purifyingunit comprises a main case, a refrigerating case, a heating case and a humidifying fresh-air preheating case. A partition layer is arranged inside the main case and divides the inside of the main caseinto an air mixing layer and an air flow equalizing layer; a heating case communicating port and a refrigerating case communicating port are respectively preset in the front side wall and the back side wall of the main case; a humidifying fresh-air preheating case communicating port is preset in the right side wall of the main case; the refrigerating case is communicated with the refrigerating case communicating port, the heating case is communicated with the main case through the heating case communicating port, and the humidifying fresh-air preheating case is communicated with the main casethrough the humidifying fresh-air preheating case. According to the requirement on the level of the clean room, the laminar flow purifying unit realizes air supply, returning, fresh air supply, temperature and humidity regulation, sterilizing,purifying, filtering and silencing of the clean room are achieved.

The invention discloses a P-band three-dimensional broadband composite wave-absorbing metamaterial and a preparation method thereof. The P-band three-dimensional broadband composite wave-absorbing metamaterial is formed by vertically arranging structural units of a metal type electromagnetic metamaterial based on magnetic metal on a ferrite dielectric substrate; a structural unit of the metal type electromagnetic metamaterial is formed by arranging two metal rings of different sizes on the front face and the back face of an FR4 dielectric substrate. The invention also comprises a preparation method of the P-band three-dimensional broadband composite wave-absorbing metamaterial. The P-band three-dimensional broadband composite wave-absorbing metamaterial is simple in structure, the overall thickness is smaller than 20 mm, the production cost is low, the metamaterial has good P-band broadband radar absorption performance in different polarization directions under the condition of vertical incidence of electromagnetic waves, the reflection loss in the full band of the P-band (230-1000 MHz) is all superior to-10 dB, the peak reflection loss can reach-45.05 dB. The preparation method is easy and convenient to operate, modular assembly is easy, and engineering application is facilitated.

The invention relates to a magnetic lead screw type eddy current damper with a negative stiffness nonlinear energy trap. The magnetic lead screw type eddy current damper comprises a spring mass system, an inertia mass system, an eddy current damping system, a negative stiffness system and a supporting system. The spring mass system comprises a spring and a balancing weight, the inertia mass systemcomprises a flywheel, a magnetic lead screw nut pair and a magnetic suspension thrust bearing, the eddy current damping system comprises a straight permanent magnet, a conductor plate and back iron,the supporting system comprises a guide rod, a supporting bracket and an outer frame, and the negative stiffness system comprises a synonym permanent magnet group and / or a homonymous permanent magnetgroup. According to the damper, the inerter principle is introduced, physical balance weight is reduced, the mass ratio of the device is increased, and meanwhile the spring net elongation of a low-frequency structure controlled by the device is reduced. The negative stiffness nonlinear energy trap element is introduced, and resonance energy can be captured in a wide frequency range. By adopting the magnetic lead screw nut pair, the friction between a lead screw and a nut is eliminated, and the working efficiency is improved. Meanwhile, the magnetic suspension thrust bearing is used cooperatively to ensure that the flywheel is suspended in a flywheel chamber to work normally.