35 results about "Invisibility cloak" patented technology

A cloaking apparatus and method are disclosed herein. The cloaking apparatus for cloaking a target object using meta-material includes a compensation unit, and a cloaking cell. The compensation unit is disposed in a second space surrounding part of a first space including the target object, and is composed of a first meta-material having a predetermined negative refractive index. The cloaking shell is configured to surround part of the compensation unit, and is composed of a second meta-material. The negative refractive index may be a negative refractive index that is adapted to cloak the target object by compensating for the positive refractive index of the first space.

An electromagnetic pulse protection invisibility cloak (1) having an elliptical structure. The invisibility cloak consists of multiple stacked elliptical loop protection layers (10), wherein each of the loop protection layers (10) is provided with multiple elliptical tracks arranged from an inner side to an outer side, and each of the elliptical tracks is provided with multiple sequentially arranged protection units (100). The electromagnetic pulse protection invisibility cloak of the present invention can fully reflect, absorb, or attenuate electromagnetic pulses, such that a protected object is not influenced by the electromagnetic pulses.

The invention provides an adjustable and controllable two-dimensional thermal invisibility cloak based on multiple annular graphene layers. The adjustable and controllable two-dimensional thermal invisibility cloak is formed in the manner that with the center of the x-y horizontal plane as the axis, prolongation of annular graphene layers is conducted layer by layer in the x-axis direction and the y-axis direction. All the layers can correspond to different thermal conductivity coefficients through control over the Fermi level distribution of graphene in the different annular layers, and then two-dimensional thermal conductivity distribution needed by thermal invisibility is obtained; then, after thermal flow winds around the cloak area, a temperature field recovers original distribution, and therefore the thermal invisibility function is achieved; and an object at the center of the thermal invisibility cloak is sheltered from external thermal flow disturbance, and external thermal flow distribution is not influenced. The real-time switching on / off performance of the thermal invisibility cloak is achieved through circular control over the Fermi level distribution of the each annular graphene layer, and therefore the defect that the two-dimensional thermal invisibility cloak cannot be circularly switched on or off is overcome.

The invention discloses an anti-reconnaissance camouflage "invisibility cloak" generation method oriented to a deep pedestrian re-identification system, and proposes an optimization method based on matching difference minimization, combined with multi-position sampling to generate noise patterns that are variable across cameras and positionally scalable , so that at any position in the monitoring area of ​​the pedestrian re-identification system, the same noise pattern cannot be matched with each other captured by different cameras, and they are all wrongly matched with a specific user. In addition, this method incorporates physical environment factors into the noise pattern generation process to improve the robustness of noise information loss during printing and shooting. The anti-reconnaissance camouflage "invisibility cloak" generated by this method can prevent the pedestrian re-identification system from correctly searching and locating the attacker, and trick the system into matching it with a specific user set in advance.

The present application discloses a raw material composition for preparing a photocurable resin, a photocurable resin prepared therefrom and use thereof, belonging to the field of curable resin synthesis. The raw material composition for preparing the photocurable resin comprises cyanate ester, photocurable prepolymer, diluent, catalyst and photoinitiator. The photocurable interpenetrating polymer network structure resin is obtained from the composition through ultraviolet light curing and thermal curing. The raw material composition for preparing the photocurable resin of the present application has both the characteristics of rapid prototyping of photosensitive resin and the characteristics of excellent heat resistance and moisture resistance of cyanate ester. The photocurable interpenetrating polymer network structure resin of the present application has low viscosity and is easy to process, and has the advantages of high strength, high temperature resistance, low shrinkage, low water absorption and low dielectric constant, etc., and can be used for 3D printing, coating, bonding, etc. Agents, aerospace materials, printed circuit boards, invisibility cloaks, artificial satellites, flame retardant materials and electronic packaging.

The invention discloses a polydimethylsiloxane / graphene flexible composite film with negative dielectric constant and a preparation method thereof. Mix the precursor and curing agent of polydimethylsiloxane with a non-polar organic solvent and add graphene with a mass fraction of 3% to 4%. The non-polar organic solvent and the mass of the precursor Equal; graphene is evenly dispersed in the solution to form a mixed slurry, take the mixed slurry and pour it on the flat plate, so that the mixed slurry is evenly coated on the surface of the flat plate, after curing treatment and peeled off from the flat plate, polydimethylsiloxane is obtained / Graphene flexible composite film. The thickness of the composite film is 0.1-2 mm. The flexible composite film provided by the invention has a negative dielectric constant, has the characteristics of simple process, low cost and easy large-scale production, and has important application value in the fields of wearable devices, sensors, invisibility cloaks and flexible electronic devices.

The invention provides an adjustable and controllable three-dimensional thermal invisibility cloak based on multiple annular graphene layers. The adjustable and controllable three-dimensional thermal invisibility cloak is achieved through a surface covering shell layer composed of graphene. The surface covering shell layer is formed in the manner that the multiple graphene annular layers are stacked from bottom to top. All the layers can correspond to different thermal conductivity coefficients through control over the Fermi level distribution of graphene in the different annular layers, and then three-dimensional thermal conductivity distribution needed by thermal invisibility is obtained; and then, after thermal flow winds around the cloak area, a temperature field and an isotherm recover original distribution, and therefore the thermal invisibility function is achieved. Meanwhile, the real-time switching on / off performance of the thermal invisibility cloak is achieved through circular control over the Fermi level distribution of graphene in each annular layer, and therefore the defect that the thermal invisibility cloak cannot be circularly switched on or off is overcome.

Provided in the present invention is an electromagnetic pulse protection invisibility cloak having a spherical structure. The invisibility cloak consists of multiple stacked protection layers. An annular ground plate is provided at a lower portion of the invisibility cloak. Multiple metalized tubes are provided within the invisibility cloak. The metalized tubes pass perpendicularly through the protection layers, and are connected to the annular ground plate. Each of the protection layers is provided with multiple circular tracks arranged from an inner side to an outer side. Each of the circular tracks is provided with multiple sequentially arranged protection units. The metalized tubes pass perpendicularly through the protection layers and are connected to the annular ground plate. The metalized tubes are provided with metalized holes. The protection units comprise four inductors connected in parallel and one capacitor, and the capacitor is connected to the metalized holes. The present invention can be implemented to fully reflect, absorb, or attenuate electromagnetic pulses, such that a protected object is not influenced by the electromagnetic pulses.

The invention belongs to the technical field of acoustics, and in particular relates to a time-domain broadband acoustic carpet-type invisibility cloak and a manufacturing method. By combining a broadband sound pressure local reflection theorem and a parameter optimization method, a multi-layer air square hole stacking The structure of the metasurface is the basic structural unit of the metasurface, and a time-domain broadband metasurface structure is designed by using genetic algorithm reverse optimization; Stealth, its relative bandwidth has reached more than 93%, and at the same time, it exhibits the stealth performance of time-domain broadband under the incidence of multi-frequency pulses, breaking the limitation of narrow bandwidth of traditional passive metasurfaces and the defects of tunable metasurfaces time-domain broadband. The structural design of acoustic metasurfaces and the practical application of broadband acoustic devices provide a key research basis.

The invention discloses a concave-convex curved carpet invisibility cloak and a design method thereof. The concave-convex curved carpet invisibility cloak is composed of M*N metasurface units that are periodically extended and arranged at equal intervals in space. The unit includes a three-layer structure from top to bottom, the first layer is an ultra-thin dielectric plate printed with double-ring metal resonators, the second layer is a resin dielectric layer, and the third layer is an ultra-thin metal plate; is formed on the resin medium layer, and the ultra-thin metal plate is conformally formed at the bottom of the resin medium layer; the resin medium layer is a curved surface structure, which is prepared and processed by 3D printing technology; One side of the ultra-thin dielectric board is printed with double-ring metal resonators by PCB technology, and the other side is fully corroded. The carpet stealth cloak of the present invention can be conformal to a cloaked target with any shape, and can also avoid the edges and corners generated at the splicing position of the existing two-dimensional plane splicing structure from affecting the working performance of the carpet stealth cloak.

Provided in the present invention is an electromagnetic pulse protection invisibility cloak having an irregular polygonal structure. The electromagnetic pulse protection invisibility cloak having a circular structure consists of multiple stacked irregular polygonal protection layers, wherein each of the irregular polygonal protection layers is provided with multiple protection units arranged from an inner side to an outer side. The present invention can be implemented to fully reflect, absorb, or attenuate electromagnetic pulses, such that a protected object is not influenced by the electromagnetic pulses.

The invention discloses a design method of a thin-shell-type acoustic superstructure in any curved surface shape. The design method is used for design of a thin-shell-type low-and-medium-frequency broadband sound insulation structure, design of a curved surface shell-shaped ultra-thin light sound absorption structure, design of an ultra-thin carpet-type acoustic invisibility cloak fitting the complex curved surface shape, and the like. According to the thin-shell-type sound insulation structure designed through the method, after the curvature radius is decreased to a certain range, a sound insulation index curve can break through the cut-off frequency limit between a stiffness control area and a damping control area, the sound insulation trough at the cut-off frequency is eliminated, and excellent low-frequency broadband sound insulation performance is achieved. By properly selecting the separation distance between double-layer shells, a double-layer shell structure can achieve bianisotropic perfect sound absorption; and in order to adjust phase compensation of the designed complex curved surface shape structure and achieve the function of arbitrary adjusting and control of a wavefront phase, the equiphase design method is adopted, and the curved surface carpet-type acoustic invisibility cloak completely fitting the complex structure surface morphology can be designed.

The invention provides a controllable three-dimensional thermal invisibility cloak based on multilayer two-dimensional topological materials. The controllable three-dimensional thermal invisibility cloak is realized by a surface covering shell layer composed of the two-dimensional topological materials, wherein the surface covering shell layer is composed of multiple two-dimensional topological material ring layers which are stacked up from bottom to top, and by controlling the crystallization degree of the two-dimensional topological materials in the different ring layers, each layer can correspond to a different thermal conductivity coefficient, so that the three-dimensional thermal conductivity distribution required by thermal invisibility is obtained; moreover, the thermal field can be restored to the original distribution after heat flow bypasses a cloak area, and the thermal invisibility function can be realized. Meanwhile, by circularly controlling the crystallization-reverse crystallization process of the two-dimensional topological materials in each ring layer, the real-time switching on / off performance of the thermal invisibility cloak is realized, thereby overcoming the disadvantage that a thermal invisibility cloak cannot be switched on / off circularly.

An electromagnetic pulse protection invisibility cloak (1) having a curved structure. The invisibility cloak consists of multiple stacked curved protection layers (10). Each of the curved protection layers (10) has multiple protection units (100) arranged from an inner side to an outer side. The electromagnetic pulse protection invisibility cloak (1) of the present invention can fully reflect, absorb, or attenuate electromagnetic pulses, such that a protected object is not influenced by the electromagnetic pulses.

The invention provides a multilayer paraffin composite phase transition material based adjustable two-dimensional optical invisible cloak. Paraffin composite phase transition material circular layers extend in the direction of an X and y axes layer by layer with the center of an x-y plane as an axis to form the adjustable two-dimensional optical invisible cloak; the solid-liquid state of paraffin composite phase transition materials in different circular layers can be controlled as so to allow various layers to correspond to different dielectric constants and magnetic conductivity coefficients, a two-dimensional dielectric constant and magnetic conductivity coefficient distribution which are desired by optical invisibility can be acquired, and then after light bypasses through a cloak zone, a light field resumes original distribution, the optical invisible function can be achieved, external light interference on an article in the center of the optical invisible cloak can be shielded, and external light field distribution cannot be affected. the solid-liquid state of the paraffin composite phase transition material in each circular layer can be controlled circularly, real-time on / off performance of the optical invisible cloak can be achieved, and the defect that the two-dimensional optical invisible cloak cannot allow circular on-off can be overcome.

The invention relates to a novel fish tank, which includes a rectangular tank body, and is characterized in that: the tank body is provided with a plurality of glass partitions, the glass partitions divide the tank into a plurality of areas, some areas are filled with water, and some areas are filled with water. The area is air; the light is incident from the first long side of the rectangular cylinder, and after multiple refractions, exits from the second long side of the rectangular cylinder, and the incident light and the outgoing light are on the same straight line.

A two-dimensional thermal invisibility cloak processing method based on reverse identification and a thermal invisibility cloak, the method comprising: establishing a two-dimensional coordinate system x-y and determining that the area surrounded by the two-dimensional coordinate system is a design area of ​​a two-dimensional thermal invisibility cloak, Solve the governing equation of the dimensionless temperature field based on the boundary conditions to obtain the dimensionless background temperature field of the design area, solve the governing equation of the direct problem based on the boundary conditions to obtain the dimensionless temperature field of the direct problem of the thermal conductivity of the region Z3, and solve the thermal conductivity of the region Z3 Accompany the problem to obtain the Lagrangian multiplier, calculate the derivative of the objective function of the thermal conductivity of the region Z3, the conjugate coefficient, and the iterative direction coefficient of the thermal conductivity of the region Z3, solve the sensitivity problem of the thermal conductivity of the region Z3, and calculate the thermal conductivity of the region Z3 The iterative step of , update the thermal conductivity of zone Z3, and calculate the objective function, if the value is small enough to meet the user's requirements, the thermal conductivity of zone Z3 is processed, otherwise return to the third step.