179results about How to "Reduce reflection loss" patented technology

The invention discloses a solar cell which comprises a silicon substrate, the surface of at least one side of the silicon substrate is provided with a micro-suede of a sand dune-like structure, and a tunneling oxide layer is laminated on the micro-suede; the sand dune-like structure is provided with at least one vertex, and 3-6 curved side edges pass through each vertex; and the side edges are sunken towards the inner part of the sand dune-like structure. The invention also provides a preparation method of the solar cell. According to the solar cell, the surface reflectivity of the solar cell can be effectively reduced, and the characteristics of surface passivation, surface contact and the like are improved, so that the transmission efficiency and the collection efficiency of carriers are improved, and the short-circuit current density and the conversion efficiency of the solar cell are further improved.

The invention provides a solar frequency division PV / T system coupled with a micro-nano film and a cavity type heat collector. The solar frequency division PV / T system comprises a linear Fresnel lens and the cavity type solar heat collector. A lighting window is formed in the heat collector in the axis direction, a micro-nano frequency division film is arranged on the inner wall face, right facing the lighting window, of a heat absorption cavity, and a concentrating photovoltaic cell is arranged below the micro-nano frequency division film. Sunlight is concentrated to the lighting window through the linear Fresnel lens at the top, is secondarily reflected by the lighting window to be collected to the cylindrical heat absorption cavity of the heat collector and irradiates the micro-nano film at the bottom, the micro-nano film transmits available wave bands in solar spectrum to the photovoltaic cell for power generation, light of other wave bands is reflected to the inner wall face of the heat absorption cavity, and the light of the other wave bands is reflected to the inner wall face of the heat absorption cavity. The heat is absorbed by the heat absorption coating, converted into heat energy and transmitted to the working medium layer, so that gradient utilization of the full spectrum of the sun is realized. The cavity type heat collector structure can effectively reduce energy dissipation caused by radiation and convective heat transfer, and the solar energy utilization efficiency of the system is improved.

The invention discloses a dual circularly polarized common aperture phased array antenna applied to low orbit satellite communication, comprising M * N antenna array sub-arrays, the M * N antenna array sub-arrays are uniformly distributed in M rows and N columns, each antenna array sub-array comprises four antenna units, the four antenna units are uniformly distributed in 2 rows and 2 columns, any antenna unit can completely coincide with the other three antenna units when rotating by a certain angle with the central axis of the antenna array sub-array as the rotating axis, and the first antenna unit comprises a combined radiation layer, a first copper plate, a coupler layer and a second copper plate which are arranged from top to bottom. The coupler layer adopts an orthogonal coupler realized based on a short-circuit three-branch structure to convert an external radio-frequency signal into two radio-frequency signals with a phase difference of 90 degrees, and the two radio-frequency signals are transmitted to the combined radiation layer; the combined radiation layer adopts a linear dipole radiator with separated upper and lower parts to realize broadband design; the broadband wide-angle scanning device has the advantages of being capable of achieving wide-angle scanning, wide in frequency band, simple in overall structure and low in manufacturing cost.

One embodiment of the present invention relates to a thermoplastic resin composition for electromagnetic wave absorbers, which contains a thermoplastic resin (A), carbon nanotubes (B) having an average diameter of 1-15 nm, and carbon black (C) having an average primary particle diameter of 20-50 nm, and satisfies any one of (i)-(iv), in which [Delta] RL represented by formula (1) is 3 dB or less, and [Delta] TL represented by formula (2) is 5 dB or less.

The invention provides an oil well optical cable for underground earthquake monitoring. The oil well optical cable comprises an optical fiber; the steel wire rope is coated with a rubber coating layer, the optical fiber is embedded in the surface of the rubber coating layer, and the optical fiber and the rubber coating layer are integrated; the outer layer of the optical fiber protection tube is coated with a sheath, and the steel wire rope is placed in the optical fiber protection tube; the high-temperature ointment is filled between the optical fiber protection tube and the rubber coating layer; and the outer-layer protection pipe adopts a high-strength seamless stainless steel pipe and is used for protecting internal elements. According to the oil well optical cable for underground earthquake monitoring, special packaging of the optical fibers is realized, mechanical protection of the optical fibers can be effectively realized, invasion of water, oil and other corrosive gases in an underground high-temperature and high-pressure environment can be avoided, the vibration sensing sensitivity of the optical fibers can be ensured, and the vibration sensing accuracy is improved. Effective physical and chemical protection can be achieved during optical fiber working, and hydrogen loss is reduced.

The invention provides a dual-band metasurface antenna array applied to radar imaging, which comprises at least one metasurface antenna unit arranged in an array, and the metasurface antenna unit is provided from top to bottom: a metasurface layer, the surface of which is laid with a patch group for exciting a characteristic mode, the patch group comprises a plurality of square patches which are laid in a square area and a plurality of right triangle patches which are separately arranged at the corners of the square area, and at least one gap is etched in at least one square patch; a first dielectric layer; the seamed grounding plate is etched with a drum-shaped gap; a second dielectric layer; and the feeder line layer comprises a long-strip feeder line and a T-shaped power divider arranged at the top of the long-strip feeder line, the antenna is excellent in return loss, gain, radiation pattern and the like, has relatively wide dual-frequency working bandwidth and remarkable high gain, and can meet the application requirements of wireless communication, radar systems and other high-performance signal transmission.

The invention provides a preparation method of a carbon / magnetic metal / aramid nanofiber composite aerogel wave-absorbing material, and belongs to the field of wave-absorbing material preparation, and the preparation method comprises the following steps: (1) respectively preparing a polyvinyl alcohol solution, an aramid nanofiber solution, a polyphenol solution and a magnetic metal salt solution; (2) sequentially adding the aramid nanofiber solution, the polyphenol solution and the magnetic metal salt solution into the polyvinyl alcohol solution, and stirring at room temperature to uniformly disperse the mixed solution; and (3) pouring the uniformly dispersed solution into a mold for freezing and freeze-drying. And (4) finally, carbonizing the dried sample in an inert atmosphere to obtain the carbon / magnetic metal / aramid nanofiber composite aerogel. The method is easy to operate and environmentally friendly, and the prepared carbon / magnetic metal / aramid nanofiber composite aerogel has excellent wave absorbing performance and mechanical performance.

The invention aims to provide a new energy high-frequency wire harness design method based on electromagnetic compatibility optimization, and relates to the technical field of new energy, and the method comprises the steps: 1, building a new energy high-frequency wire harness type electromagnetic source model, and obtaining the electromagnetic source intensity; calculating a spatial electromagnetic field intensity based on the electromagnetic source intensity; step 2, calculating equivalent transmission line parameters based on the space electromagnetic field intensity; based on the equivalent transmission line parameters, frequency-dependent characteristic impedance is calculated; step 3, calculating crosstalk voltage according to the frequency-variable characteristic impedance; calculating a radiation field of the new energy high-frequency wire harness; calculating the shielding effectiveness of the new energy high-frequency wire harness according to the radiation field; 4, according to the step 1, the step 2 and the step 3, constraint conditions are set, an objective function under the constraint conditions is established, and the objective function is solved through iteration to find the corresponding optimal design parameter vector of the new energy high-frequency wire harness. According to the invention, the transmission stability and the anti-interference capability of the new energy high-frequency wire harness are significantly improved.

The invention relates to a preparation method of a double-layer photo-thermal membrane distillation material, and belongs to the technical field of membrane distillation. According to the double-layer film, a polyvinylidene fluoride super-hydrophobic film serves as a hydrophobic base layer, a carbon nano tube / nano semiconductor material composite nano film serves as a photo-thermal layer, and the photo-thermal layer is attached to the hydrophobic base layer through polyurethane. The preparation method is characterized by comprising the following steps: (1) preparing an electrostatic spinning polyvinylidene fluoride super-hydrophobic membrane; and (2) preparing the electrostatic spinning carbon nano tube / nano semiconductor material composite nano film. Meanwhile, the invention provides a photo-thermal driving membrane distillation device. The double-layer photo-thermal membrane distillation material prepared by adopting the method has good photo-thermal conversion capacity, relatively high water vapor flux and long-term stability, and has a wide application prospect in the aspect of fresh water treatment.

The invention provides a light broadband wave-absorbing structure based on 3D printing and a resistive film and a preparation method thereof.The light broadband wave-absorbing structure comprises a metal bottom layer, a supporting layer, a resistive film layer and a structural wave-absorbing material layer which are sequentially arranged from bottom to top, the structural wave-absorbing material layer is of a 3D printing structure and is made of CNTs doped with ABS, and the supporting layer is made of carbon nanotubes doped with ABS. Periodic units of the 3D printing structure are two kinds of regular hexagonal cylinder periodic units with different sizes. The CNTs-doped ABS 3D printing structure is introduced into the single-layer resistive film wave-absorbing structure, the 3D printing structure, the size and the resistance value of the resistive film are optimized, the wave-absorbing structure small in thickness and weight is obtained, meanwhile, the wave-absorbing structure has excellent wave-absorbing performance, and the reflection loss is smaller than-10 dB within 2.0 GHz to 18 GHz.

The invention provides a super-lens based on a double-coupling structure, and relates to the field of optical zooming, the super-lens comprises a substrate and a phase wave front arranged on the substrate, the phase wave front is composed of a plurality of nano-columns arranged periodically, a corresponding phase distribution value is given according to the position point of each nano-column, and the phase distribution value is calculated according to the position point of each nano-column. The phase wavefront is arranged on the substrate, the phase wavefront is arranged on the substrate, the phase wavefront is arranged on the phase wavefront, the nanometer columns are arranged on the phase wavefront to convert plane waves incident to the phase wavefront into light beams focused at a specified focal length, each nanometer column has the same rectangular cross section, a slit is formed in the long axis direction of each nanometer column, and the slits penetrate through the nanometer columns and extend to the surface of the substrate. And thus, the nano-columns form a double-coupling structure. According to the invention, the focusing efficiency of the super lens can be improved.

The invention provides a crystalline silicon solar cell with high conversion efficiency and a preparation process thereof, and belongs to the technical field of solar cell preparation. The preparation process comprises the following steps: pretreating a crystal silicon wafer; preparing a bionic micro-nano composite film; preparing a composite structure on the surface of the silicon wafer; preparing the glass powder doped with the phosphorus-doped graphene; preparing a positive electrode conductive slurry; and preparing the crystalline silicon solar cell. The CuS nanocrystals / quantum dots are deposited on the surface of the bionic micro-nano composite film, the effects of antireflection, passivation and sensitization of the silicon wafer can be achieved, the photoelectric conversion efficiency of the battery is further improved, the CuS nanocrystals / quantum dots are deposited, the absorption range of the silicon wafer to the optical wavelength can be increased, and the photoelectric conversion efficiency of the battery is improved. Meanwhile, one absorbed photon can be converted into a plurality of photon-generated carriers through the CuS quantum effect, and the photoelectric conversion efficiency of the cell is improved.

The invention provides a laser transfer printing film preparation method and a transfer printing film, and the method comprises the steps: providing a substrate which comprises a first surface and a second surface which are oppositely arranged; a plurality of grooves are formed in the direction, close to the second surface, of the first surface; an anti-reflection layer is prepared on the second surface, the anti-reflection layer is cured, and the second surface is covered with the anti-reflection layer; a hydrophobic and oleophobic layer is prepared on the first surface with the grooves, the hydrophobic and oleophobic layer is cured, and the first surface and the grooves are covered with the hydrophobic and oleophobic layer. On the basis of an existing laser transfer printing film structure, a transparent coating with hydrophobic and oleophobic characteristics is added to the front face, and slurry can be completely separated from a transfer printing template, so that silver slurry is saved, and the height-width ratio of a grid line is increased. In addition, an anti-reflection layer is additionally arranged on the back face, reflection loss generated when laser penetrates through the transfer printing film is reduced, enhancement of actual laser power is ensured, and then the use efficiency of the laser is improved.

The invention relates to the technical field of head-up displays based on automobile windshields, and discloses a small-size head-up display and an arrangement method thereof.The small-size head-up display comprises an image source, a lens, a reflector and an eye box, the lens is located between the image source and the reflector, and the eye box is located between the lens and the reflector. Imaging light beams emitted by the image source enter the reflecting mirror through the lens, the reflecting mirror reflects the imaging light beams to an automobile windshield, the imaging light beams are reflected to the eye box through reflection of the automobile windshield, finally, a virtual image is formed in the range of the eye box, and a driver can see the virtual image in the air in the range of the eye box. The invention further discloses a method for arranging the positions of the lens, the reflecting mirror and the eye box, a light path is shortened by adopting one reflecting mirror and one lens, the overall size of the displayer is reduced, optical distortion and reflection loss are reduced through the reasonable arrangement method, the definition and brightness of images are improved, and therefore the wide vehicle type adaptability is achieved.

The invention provides a low-loss substrate integrated transmission line structure and a preparation method thereof.The low-loss substrate integrated transmission line structure comprises a first substrate, a circuit penetrating in the length direction of the first substrate, metal layers arranged on the upper side and the lower side of the first substrate and a second substrate arranged above the metal layers on the two sides; the first substrate is provided with a plurality of air holes penetrating in the height direction of the first substrate, the air holes are evenly divided into two groups to be arranged on the two sides of the circuit, and every two adjacent air holes are arranged at equal intervals. The circuit adopts a periodic line width structure; in the first substrate, the outer sides of the two groups of air holes are respectively provided with a group of metal holes penetrating along the height direction of the first substrate to form shielding. The dielectric loss and the reflection loss of the substrate are reduced, the overall performance of the transmission line is improved, a more reliable solution is provided for high-frequency signal transmission, and wide application prospects are achieved.

The invention discloses a broadband 1-bit reconfigurable transmission array antenna unit based on a polarization rotating metasurface. The broadband 1-bit reconfigurable transmission array antenna unit comprises a top layer metal grating, a middle layer metal covering face, a lower layer metal covering face and a bottom layer metal covering face. The middle-layer metal covering surface comprises a PIN diode, a split circular ring, a first metal bias line and a second metal bias line; the split circular ring is composed of two sections of circular arcs, the number of the PIN diodes is two, the PIN diodes are connected between the two sections of circular arcs to form a complete circle, and the first metal bias line and the second metal bias line are connected to the split circular ring and serve as a direct current input end and a grounding end respectively; the lower-layer metal covering surface comprises a metal grating and a first metal column, and the first metal column connects the metal grating with the second metal bias line; the underlying metal cladding includes a second metal pillar and a metal bias line, the second metal pillar connecting the metal bias line with the metal first bias line. The invention has the advantages of broadband, high efficiency and reconfigurable phase, and can be used for a broadband wave beam electric scanning transmission array.

The invention provides a substrate integrated trapped wave mirror image dielectric waveguide S-shaped circularly polarized antenna, which belongs to the field of antennas and comprises an S-shaped dielectric radiator, a metalized through hole, a microstrip feeder line, a first metal grounding plate, a first dielectric substrate, a second metal grounding plate and a second dielectric substrate, the S-shaped dielectric radiator is embedded in the first dielectric substrate and located in the center of the antenna, the lower surface of the S-shaped dielectric radiator is tightly attached to the second metal grounding plate, the upper surface of the S-shaped dielectric radiator is not covered, a plurality of metalized through holes penetrate through the first dielectric substrate and are arranged on the periphery of the S-shaped dielectric radiator in an array mode, and a gap is formed in the second metal grounding plate. The microstrip feeder is located on the lower surface of the second dielectric substrate and is perpendicular to the gap. The end, away from the gap, of the microstrip feeder is connected to a feed port in the second dielectric substrate. Circular polarization is easy to realize by combining the bent dielectric structure with the slot coupling feed at the bottom, and the radiation efficiency of the antenna is improved by using the notch mirror image structure in the antenna design.

The invention provides a hollow-core-to-hollow or solid-core-to-hollow optical fiber connection jumper wire and a preparation method thereof. The jumper wire comprises a transmission fiber and connectors connected to the two ends of the transmission fiber. The transmission fiber is a hollow-core optical fiber, the connector comprises an optical fiber fixing device and an integrated welding structure fixed in the optical fiber fixing device, the integrated welding structure comprises a transmission fiber, a coating film and a transition fiber which are fixedly connected in sequence, the coating film performs anti-reflection on a set wavelength, the transition fiber is a solid-core optical fiber, and the outer side end of the transition fiber serves as the output end of the connector; and the output ends of different connectors are oppositely arranged so as to realize transmission connection between different jumpers. Pluggable, stable and reliable connection between the hollow-core optical fibers or between the hollow-core optical fibers and the solid-core optical fibers is achieved.

The invention relates to the technical field of wireless communication, and discloses a phase shifter based on a slow-wave transmission line and a base station antenna, and the phase shifter comprises an input port, a plurality of phase shifting segments, a plurality of matching segments and a plurality of output ports. The input port is arranged at the middle position of the phase shifter and is used for receiving an input signal; the phase shift section comprises a dielectric substrate and two layers of slow wave transmission lines arranged on the dielectric substrate, and is used for adjusting the phase of an input signal; the matching section is connected between the adjacent phase shifting sections and is used for matching impedance; and the plurality of output ports are distributed on two sides of the phase shifter in a mirror image manner, so that signal distribution of the plurality of output ports is realized. According to the invention, through the design of the plurality of output ports, different phase adjustments are provided for the plurality of output ports at the same time; through the structural design of the phase shift section, the signal has higher phase adjustment flexibility in the transmission process; the impedance is matched through the matching section, reflection and signal loss can be reduced to the maximum extent, and effective transmission of signals is ensured.

The invention belongs to but not limited to the technical field of antennas, and particularly relates to an automatic tuning transmitting antenna and method for RS103 testing, and the antenna comprises an antenna array pipeline which enables a length-variable antenna array to stretch out and draw back in the pipeline; the tunable antenna array is made of soft and thin copper foil, can bear large current and is wound on a rotary column of the program control motor, and the length of the antenna array is adjusted through rotation of the program control motor; the optical fiber interface is connected with an optical fiber of a program control motor, and program control of the motor used by the antenna array is completed through program control software of the test system; the coaxial port is connected with an output power coaxial line of the radio frequency power amplifier, so that the output power of the radio frequency power amplifier is transmitted to the antenna array, and the antenna array generates required field intensity at a position of 1m; and the program control motor is used for controlling the lengths of the antenna arrays at different frequencies, controlling the rotation of the motor through the program control software of the test system, and adjusting the lengths of the arrays.

This invention provides an infrared thermal imaging method, relating to the field of infrared thermal imaging technology. The method utilizes a germanium infrared lens in an infrared thermal imaging system, whose surface is sequentially composed of subwavelength micro / nano structures and an anti-reflection film structure from the inside out. The infrared thermal imaging method includes: focusing target infrared radiation through the germanium infrared lens onto an infrared detection array; the infrared detection array converting the target infrared radiation into an electrical signal matrix; performing noise reduction and gain correction on the electrical signal matrix to obtain a preprocessed electrical signal matrix; performing temperature compensation on the preprocessed electrical signal matrix based on a temperature compensation formula and a transmittance temperature model to obtain a corrected signal matrix; and sequentially performing non-uniformity correction, image enhancement, and pseudo-color mapping on the corrected signal matrix before outputting and displaying the result. Using the method of this invention, higher transmittance, lower reflection loss, and more stable thermal imaging can be achieved.

The utility model relates to the technical field of retroreflective sheeting provides an environmental protection type hard PVC retroreflective sheet, solves the problem that the reflectivity of existing retroreflective sheet is low, and the optical performance is relatively weak, and the surface layer anti -peeling impact force is not good, including the retroreflective sheet body, the retroreflective sheet body includes the protective surface layer, prism air microcapsule layer, degradable back film layer from top to bottom sequentially laminated, the prism air microcapsule layer includes wall material and core material, the core material includes prism reflection matrix layer and air layer, the protective surface layer is by PVC material layer and acrylic material layer composite, the prism reflection matrix layer is by several microangle pyramid prism structure unit close arrangement, the microangle pyramid prism structure unit is cutting obtains to cubic angle pyramid prism.

The application provides a fiber-optic Fabry-Perot sensor based on light beam convergence and a manufacturing method thereof, and relates to the technical field of semiconductors. The sensor comprises a diaphragm layer, an intermediate layer and a bottom layer which are arranged in layers; the diaphragm layer is provided with a first groove, the intermediate layer is attached to the diaphragm layer in a manner that a first layer surface thereof faces the first groove, so as to form a Fabry-Perot cavity based on the first groove; the bottom layer is provided with a second groove, the intermediate layer is attached to the bottom layer in a manner that a second layer surface thereof faces the second groove, so as to form a nano-containing cavity based on the second groove; the second layer surface of the intermediate layer is formed with a micro-nano anti-reflection structure comprising array-distributed anti-reflection units located in the nano-containing cavity; and the bottom layer is formed with a micro-nano collimation structure comprising array-distributed collimation units located in the nano-containing cavity and in a symmetrical positional relationship with the micro-nano anti-reflection structure. The application at least reduces the manufacturing complexity.

The application discloses a kind of self-sealing inorganic sealing welding LED light source and inorganic sealing welding method, LED light source includes substrate, LED chip and light window, substrate top surface is equipped with electrode layer, welding layer, and LED chip is welded on electrode layer;Light window includes tube shell, lens, and the lower end of tube shell is welded on welding layer;It is equipped with ring cup-shaped light cup around LED chip in tube shell, and the outer side of the bottom surface of light cup is equipped with the positioning gap of opening outward along circumference, and the corresponding position of welding layer is equipped with the positioning dam for cooperating with positioning gap to position light cup, and positioning dam is equipped with the sealing glue for bonding fixed light cup, and part of sealing glue overflow is connected with welding layer and is sealed;Positioning dam includes inner dam, middle dam and outer dam sequentially arranged from inside to outside, and satisfy middle dam height h2>Inner dam height h1≥Outer dam height h3.The application has the advantages of good air tightness and high light extraction efficiency.

The invention relates to a semiconductor structure and a forming method thereof, the semiconductor structure comprises a first substrate, the first substrate comprises a plurality of mutually discrete photosensitive areas and isolation areas located between the adjacent photosensitive areas, the first substrate comprises a first surface and a second surface which are opposite, and the second surface is used as a light incident surface; the deep trenches are located in the isolation regions, the deep trenches penetrate through the first substrate in the normal direction of the surface of the first substrate, each deep trench comprises a first trench region and a second trench region, the distance from the first trench region to the first surface is smaller than the distance from the second trench region to the first surface, the first trench region has a first projection on the surface of the first substrate, and the second trench region has a second projection on the surface of the second substrate; the second groove region has a second projection on the surface of the first substrate, and the second projection is located in the range of the first projection; the isolation structures are located in the deep trenches, each isolation structure comprises a light reflection layer, the utilization rate of incident photons is improved, light transmission and reflection losses are reduced, and then the photon detection efficiency is improved.

The utility model relates to gem processing detection technical field more specifically, relate to a gem cutting and grinding process three -dimensional dynamic optical detection module, including mounting bracket, the mounting bracket includes upper roof, left side board, lower bottom plate and right side board, the upper roof, left side board, lower bottom plate and right side board combine and form the rectangular structure, wherein the middle part of upper roof is provided with fixed hole, the middle part of lower bottom plate is open, the right side and left side of lower bottom plate are provided with first off -axis parabolic mirror and second off -axis parabolic mirror respectively, the upside of first off -axis parabolic mirror and second off -axis parabolic mirror is provided with semiconductor laser and acquisition camera respectively. First off -axis parabolic mirror focuses laser to gem surface, second off -axis parabolic mirror captures the laser signal of gem surface reflection, and reflects it to acquisition camera, realizes the dynamic focusing of curved surface gem detection without aberration, and this detection mode adopts non -contact detection, avoids the damage of gem surface.

This invention relates to the field of lighting technology, and in particular to a white light supercontinuum fiber combiner, a light-emitting unit, and a method for fabricating the same, including N 2 One first input optical fiber, (N-1) 2 The first input fibers consist of a second input fiber and a square output fiber. Multiple first input fibers are arranged in a square array. One or more second input fibers are respectively disposed in the gaps formed between the multiple first input fibers. The square output fiber is fused to the tapered fused ends of the first and second input fibers. N is a natural number greater than or equal to 2. This invention's white light supercontinuum fiber combiner can transmit spectral energy with high quality, offering superior color reproduction compared to traditional white light illumination. It also meets the application requirements for high illumination brightness, effectively solving the problem of insufficient brightness in existing lighting devices.

The present invention provides a method for preparing a carbon / magnetic metal / aramid nanofiber composite aerogel absorbing material, which belongs to the field of absorbing material preparation. The preparation method comprises the following steps: (1) respectively preparing a polyvinyl alcohol solution, an aramid nanofiber solution, a polyphenol solution and a magnetic metal salt solution. (2) sequentially adding the aramid nanofiber solution, the polyphenol solution and the magnetic metal salt solution to the polyvinyl alcohol solution, and stirring at room temperature to make the mixed solution uniformly dispersed. (3) pouring the uniformly dispersed solution into a mold, freezing and freeze-drying. (4) Finally, carbonizing the dried sample under an inert atmosphere to obtain a carbon / magnetic metal / aramid nanofiber composite aerogel. The present invention is simple to operate and environmentally friendly. The prepared carbon / magnetic metal / aramid nanofiber composite aerogel has excellent absorbing performance and mechanical properties.

The application discloses a kind of natural rubber filling nickel-aluminum bimetallic hydroxide multi-walled carbon nanotube composite material for electronic component packaging, belong to packaging material technical field, the composite material includes natural rubber matrix and dispersed nickel-aluminum bimetallic hydroxide / multi-walled carbon nanotube hybrid filler, the hybrid filler is made of multi-walled carbon nanotube and nickel-aluminum layered double hydroxide grown in its surface in situ.Its preparation method is: multi-walled carbon nanotube, nickel source, aluminum source, urea and ammonium fluoride are dissolved in water and prepared hybrid filler by hydrothermal reaction;Then it is mixed with natural latex, vulcanization aid dispersion, freeze-drying, vulcanization is obtained.The application improves the dispersibility of filler by constructing LDH / MWCNT hybrid structure, uses phonon transmission optimization, synergism of loss and impedance, combustion inhibition and the friction and reinforcing mechanism of hybrid filler and natural rubber molecular chain, so that the thermal conductivity, electromagnetic wave absorption capacity, flame retardancy, mechanics and damping performance of the composite material are simultaneously improved, suitable for electronic component packaging field.

The present disclosure relates to a solar cell. The solar cell comprises: a first cell, the first cell being a narrow-bandgap solar cell, the narrow-bandgap solar cell having oppositely arranged light-receiving and back surfaces; and an anti-reflection stack located on the light-receiving surface of the narrow-bandgap solar cell; wherein the anti-reflection stack comprises a plurality of anti-reflection sub-layers; the refractive index of the plurality of anti-reflection sub-layers decreases first and then increases along a direction from the back surface to the light-receiving surface, and the refractive index of a first end of the anti-reflection stack is smaller than that of a second end. Thus, by means of the "low-high" refractive index gradient of the anti-reflection stack, the reflection of light of different wavelengths can be regulated, the light reflection loss in the target wavelength band is reduced to a minimum, the light transmission efficiency is maximized, more incident light is effectively coupled to the light absorption region of the solar cell, and the photoelectric conversion efficiency of the solar cell is improved.