150results about How to "Large aperture" patented technology

The invention relates to a preparation method and application of an organosilicon / MOF-303 mixed matrix membrane, a silicon source precursor is uniformly dissolved in an ethanol solvent, then a mixture of water and hydrochloric acid is added according to a certain proportion, a water bath heating reaction is carried out for a period of time to obtain an organosilicon sol, prepared MOF-303 powder is added into the organosilicon sol according to a certain proportion, and the organosilicon / MOF-303 mixed matrix membrane is obtained. The preparation method comprises the following steps: uniformly mixing the raw materials through ultrasound to obtain a separation layer sol, coating the prepared separation layer sol on a ceramic support body through a hot coating method, and calcining in an air atmosphere for a period of time to obtain the MOF-303 / mixed matrix membrane. An organic silicon substance BTESA with a rigid acetylene bridge structure is preferably selected as a precursor, an MOF-303 material with a high specific surface area is doped into the precursor, the pore channel structure of the membrane is modified, more adsorption sites are provided for water molecules, and the composite membrane material with the optimal separation performance is obtained by optimizing the composite proportion.

The utility model relates to a low total length 8M foresight optical lens, which is characterized in that an optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from left to right along a light incident light path. The lenses are made of plastic and glass materials, the first lens, the second lens, the fourth lens, the fifth lens and the sixth lens are glass spherical lenses, the third lens and the seventh lens are plastic aspheric lenses, and the fifth lens and the sixth lens form a balsaming lens group. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the distance between the lenses on the optical axis and the like, the total length of the lens and the radial size of each lens are reduced while the requirements of a front-view wide-angle camera and a front-view narrow-angle camera are replaced by the low-total-length 8M ultra-wide-angle imaging performance of the lens; and the lens group is miniaturized.

The invention relates to a medium-focus large-aperture long-flange video lens with a focal length of 50mm. The medium-focus large-aperture long-flange video lens comprises a first lens group, an iris diaphragm and a second lens group which are sequentially arranged along a light incidence direction of a light path, wherein the first lens group serves as an immovable fixed group, the focal power is positive, and the first lens group is composed of lenses L11-L17 which are sequentially arranged in the light incidence direction of a light path and comprises two groups of doublet lenses and a group of triplet lenses; the second lens group serves as a movable focusing group, the focal power is positive, and the second lens group is composed of lenses L21-L27 which are sequentially arranged in the light incidence direction of the light path and comprises two groups of doublet lenses and a glass aspheric lens; the focal length value f1 of the first lens group and the focal length value f2 of the second lens group satisfy 0.47 lt; f2 / f1lt; and 0.56% of the total weight. The lens achieves a large clear aperture, high MTF resolution, small distortion and reduced achromatism, is short in total optical length, and meets a camera module matched with a long flange back focus.

The utility model relates to a high-brightness low-cost DMD welcome lamp lens. An optical system of the lens is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens and a fifth lens which are sequentially arranged from left to right along a light incident light path. The lenses are made of plastic and glass materials, the first lens, the second lens, the third lens and the fourth lens are plastic aspheric lenses, and the fifth lens is a glass spherical lens. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the imaging performance requirement of the lens is met, the total length of the lens and the radial size of each lens are reduced, and the miniaturization of the lens group is realized.

The invention discloses a solid-state lithium battery and a preparation method thereof and belongs to the technical field of battery processing. The preparation method of the solid-state lithium battery comprises the following steps: S1, assembling a positive plate, a diaphragm and a negative plate into a dry cell; wherein a composite film layer is cured on a current collector base material of the negative plate, and rubidium nitrate is added into the composite film layer; s2, injecting the gel precursor solution into a dry battery cell, fully standing, and charging the battery cell to 100% SOC; wherein the gel precursor solution contains an electrolyte, a cross-linking agent and an initiator; and S3, heating to initiate a chemical cross-linking reaction of a cross-linking agent in the gel precursor solution, and carrying out in-situ polymerization and curing on the surface of each component of the dry cell and in internal pores thereof to obtain a gel polymer electrolyte, thereby forming the solid-state lithium battery. According to the invention, the interface resistance can be reduced, and the lithium ion transmission capability and efficiency are improved.

The utility model relates to a DMD welcome lamp lens with short total length, the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens from left to right along a light incident light path, the lenses are made of glass materials, the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are glass spherical lenses, the second lens is a glass aspheric lens, wherein the third lens and the fourth lens, and the fifth lens and the sixth lens form a balsaming lens group. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the imaging performance requirement of the lens is met, the total length of the lens and the radial size of each lens are reduced, and a 33 mm lens group is formed.

The invention belongs to the technical field of ethanol recovery, and relates to a preparation method of a tubular ceramic carrier-based C-ZIF-67 derived nano-porous carbon doped PDMS mixed matrix membrane and an application of the membrane in recovery of ethanol by pervaporation of a low-concentration ethanol aqueous solution. Comprising the following steps: synthesizing a ZIF-67 crystal, and carbonizing the ZIF-67 crystal to obtain C-ZIF-67 filler particles; the ZIF-67-derived nano-porous carbon particles are prepared through a high-temperature calcination method, the particles are fully carbonized at a certain calcination temperature, disappearance of characteristic groups after carbonization can reduce the influence of surface electrical properties of the particles, and the size shrinkage of the particles is reduced, so that the dispersity of the particles in a matrix membrane is improved; meanwhile, the MOF skeleton structure is still reserved after carbonization, the pore diameter is increased, the carbon material also has strong hydrophobicity, the hydrophobic large-pore-diameter separation pore channels are more beneficial to passing of ethanol molecules and promotion of the separation effect, the separation factor and the total flux are almost kept unchanged after long-time operation and use, and excellent performance is shown; good application prospects are realized.

The production line comprises a preheating furnace, a tubular furnace and a cooling furnace which are connected in sequence, the preheating furnace comprises a first furnace body, a rack, a first feeding pipe, a first discharging pipe, a preheating device and a first driving mechanism, the first furnace body is rotationally connected to the rack, and the second furnace body is rotationally connected to the rack; the two ends of the first furnace body are rotationally connected with the first feeding pipe and the first discharging pipe correspondingly, a first preheating conveying blade is arranged in the first furnace body, a material guiding barrel is arranged in the first preheating conveying blade, a second preheating conveying blade is arranged on the inner side wall of the material guiding barrel, and the preheating device and the first driving mechanism are installed on the rack. The preheating device preheats the first furnace body, and the first driving mechanism drives the first furnace body to rotate. Compared with the prior art, the catalyst carrier has the advantages that preheating and drying can be performed during preparation of the activated carbon, carbonization and activation effects are improved, carbonization and activation processes in the production process of the activated carbon can be effectively controlled, and the catalyst carrier with large aperture and high specific gravity is obtained.

The invention belongs to the technical field of polytetrafluoroethylene microporous membranes, and relates to an Al2O3 / PTFE composite microporous membrane and a preparation method and application thereof.The Al2O3 / PTFE composite microporous membrane is composed of Al2O3 nanoparticles and PTFE resin, the porosity is 65%-95%, the thickness is 3-25 microns, the average pore size is 0.10-1.5 microns, the transverse and longitudinal tensile strength is larger than or equal to 20 MPa, and the water contact angle is smaller than or equal to 90 degrees. According to the invention, the Al2O3 / PTFE composite microporous membrane is endowed with good surface wettability and excellent mechanical property by utilizing self-humidifying and in-situ reinforcement of Al2O3 nanoparticles, and the Al2O3 / PTFE composite microporous membrane is mainly applied to a reinforcing material of a proton membrane. The preparation process is simple, and industrial popularization is easy to realize.

The utility model relates to a low total length 8M foresight main camera. An optical system of the main camera is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from left to right along a light incident light path. The lenses are made of plastic and glass materials, the first lens, the second lens, the fourth lens, the sixth lens and the seventh lens are glass spherical lenses, the third lens and the fifth lens are plastic aspheric lenses, and the sixth lens and the seventh lens form a balsaming lens group. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, the total length of the lens and the radial size of each lens are reduced while the requirements of a front-view wide-angle camera and a front-view narrow-angle camera are replaced by the low-total-length 8M ultra-wide-angle imaging performance of the lens, and the miniaturization of the lens group is realized.

The invention discloses a preparation method of a composite denitration catalyst based on a Cu-BTC metal organic framework, the composite denitration catalyst and a denitration catalytic filter material, and relates to the technical field of denitration catalysis. The preparation method comprises the following steps: taking Cu-BTC as a sacrificial template, dipping the sacrificial template in a manganese acetate mixed solution with a certain concentration, carrying out rotary evaporation at a certain temperature to dryness, then putting into a drying oven to dry a sample, and finally preparing the CuO / Cu2O / Mn3O4 composite denitration catalytic material by adopting a high-temperature carbonization and high-temperature oxidation sectional calcination method. The composite denitration catalytic material prepared in the invention presents a spherical morphology with certain pores and uniform distribution, metal oxides with different valence states have excellent oxidation-reduction performance, electron transfer between NH3 and NOx is promoted, and the process of a reduction reaction is accelerated; the metal with different valence states can promote the reaction between NH3 and NOx, and the prepared composite denitration catalyst is stable in structure, low in temperature, efficient, green, environmentally friendly, non-toxic and harmless.

The invention discloses an optical lens, a camera module and a terminal device, the optical lens comprises seven lenses, the first lens has negative refractive power, and the object side surface and the image side surface of the first lens are a convex surface and a concave surface near an optical axis respectively; the second lens element with negative refractive power has a concave object-side surface and a convex image-side surface in paraxial regions, respectively. The third lens element with positive refractive power has an object-side surface and an image-side surface being convex in a paraxial region. The fourth lens element with positive refractive power has an object-side surface and an image-side surface being convex in a paraxial region thereof. The fifth lens element with positive refractive power has an object-side surface and an image-side surface being convex in a paraxial region. The sixth lens element with negative refractive power has an object-side surface and an image-side surface being concave in a paraxial region. The seventh lens element with positive refractive power has a convex object-side surface and a concave image-side surface in paraxial regions, respectively. The optical lens satisfies the following relational expressions: FOV is greater than or equal to 130 degrees and less than or equal to 160 degrees, and R6 / F3 is greater than or equal to-7.5 and less than or equal to-3.0.

The invention belongs to the technical field of biological bacteriostasis and food packaging materials, and particularly relates to a carboxymethyl chitosan-covalent organic framework-nano-silver composite material and a preparation method and application thereof. According to the preparation method of the carboxymethyl chitosan-covalent organic framework-nano-silver composite material, provided by the invention, a metagen is adopted as a reducing agent, and AgNPs is synthesized through a biological method; the COF-AgNPs composite material is prepared by an in-situ growth method, and the ordered porous structure of the COF provides specific constraint for the AgNPs, so that aggregation of the AgNPs is effectively avoided; in addition, COF-AgNPs is added into a CMCS matrix, so that the film-forming ability of the COF-AgNPs is enhanced, and the CMCS matrix is endowed with excellent antibacterial performance and mechanical performance. Therefore, the composite film material prepared by adopting the preparation process can effectively improve the fresh-keeping effect of fruits and vegetables, and has a good application prospect in the field of packaging film materials for fruit and vegetable fresh-keeping.

The embodiment of the invention provides a projection lens and projection equipment. Wherein the projection lens sequentially comprises a first lens group, a diaphragm and a second lens group from an imaging side to an image source side along an optical axis; the first lens group is composed of a first lens, a second lens and a third lens, the first lens is a plastic aspherical lens, and the second lens and the third lens are glass spherical lenses; the second lens group is composed of a fourth lens, a fifth lens and a sixth lens, the fourth lens and the fifth lens are glass spherical lenses, and the sixth lens is a glass aspheric lens; the diaphragm is positioned between the third lens and the fourth lens; the projection lens satisfies the following conditions: 2 < T / D < 3.5; wherein T is the total optical length of the projection lens, and D is the maximum effective clear aperture in the first lens group.

The invention discloses a lacidipine film-controlled sustained-release pellet capsule and a preparation method thereof, relates to the technical field of medicines, and aims to solve the problem of release reduction caused by film aging of a lacidipine film-controlled sustained-release pellet prepared by an aqueous dispersion coating. The preparation method comprises the following steps: respectively weighing a lacidipine bulk drug, a polymer carrier material and a plasticizer according to a prescription amount, grinding and uniformly mixing to prepare the lacidipine solid dispersion. A sustained-release coating film of the pellet capsule contains Eurdragit RL30D, a plasticizer triethyl citrate and an anti-sticking agent talcum powder, and a pellet core contains croscarmellose sodium and an excipient. According to the lacidipine solid dispersion solid preparation provided by the invention, lacidipine exists in the carrier material in a microcrystalline state, an amorphous state, a colloidal dispersion state or a molecular dispersion state, so that the lacidipine solid dispersion solid preparation has high dispersity, the dissolution speed of a medicine is accelerated, the absorption of the medicine can be promoted, and the bioavailability is improved.

The utility model discloses a prime lens. The prime lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens from an object side to an image side along an optical axis, the first lens has negative focal power, the object side surface is a convex surface, and the image side surface is a concave surface; the second lens has positive focal power, the object side surface of the second lens is a concave surface, and the image side surface is a convex surface; the third lens has positive focal power, the object side surface of the third lens is a concave surface, and the image side surface is a convex surface; the fourth lens has negative focal power; the fifth lens has positive focal power; the sixth lens has negative focal power, the object side surface of the sixth lens is a concave surface, and the image side surface is a convex surface; the seventh lens has positive focal power; the eighth lens has negative focal power.

The invention provides a pH-responsive on-demand drug release double-layer hydrogel patch and a preparation method thereof, and relates to the technical field of medicines.The preparation method comprises the following steps that curcumin-loaded sodium alginate microspheres are prepared through a microfluidic device; preparing drug release layer hydrogel: dissolving acrylamide and tannic acid in deionized water, adding the prepared curcumin-loaded sodium alginate microspheres, carrying out ultrasonic treatment to uniformly disperse the curcumin-loaded sodium alginate microspheres, adding a cross-linking agent and an initiator after the dispersion is finished, and after the curcumin-loaded sodium alginate microspheres are completely dissolved, putting the curcumin-loaded sodium alginate microspheres into a drying oven for incubation to obtain the drug release layer hydrogel; and preparing the double-layer hydrogel patch: uniformly mixing a PDMS component of polydimethylsiloxane and a curing agent, casting the mixture on the prepared hydrogel of the drug release layer, then putting the mixture into a drying oven for curing, and forming a protective layer on the drug release layer to obtain the double-layer hydrogel patch. The double-layer hydrogel patch prepared by the invention can respectively release different medicines for resisting bacteria and inflammation based on the pH value of the wound, so that the wound has a better healing effect.

The utility model relates to a kind of spray panels for liquid-cooled energy storage integrated cabinet, it includes plate body, the continuous fluid passage is set up on the plate body upper surface, the fluid passage is equipped with liquid inlet;Multiple spray holes are set up on the plate body, each The spray hole is all through the plate body and is communicated with the inside of the fluid passage;Along the flow direction of fluid in each branch of the fluid passage, the spray hole aperture that is away from the branch entrance is greater than the spray hole aperture close to the branch entrance;And the cross-sectional area of the fluid passage corresponding to the spray hole that is away from the branch entrance and is communicated is less than the cross-sectional area of the fluid passage corresponding to the spray hole close to the branch entrance and is communicated.The utility model realizes the effect that each hole liquid is consistent, improves energy storage cabinet battery heat dissipation uniformity.

The present invention discloses a die pressing device for a brick pressing machine, comprising a static die assembly, the static die assembly comprising a die base, a pressure cover and a lifting rod; a brick die groove is provided on the die base; the pressure cover can be lifted and lowered and distributed directly above the die base, and can be inserted and movably distributed to match the brick die groove; a mesh pressing plate is provided on the inner wall of the die base and the bottom surface of the pressure cover. The mesh pressing plate is composed of a dense mesh plate layer, a load-bearing mesh plate layer and a plurality of load-bearing support rods; the dense mesh plate layer is composed of a plurality of layers of dense mesh plates superimposed and combined; the dense mesh plate is composed of a pressure-bearing corrugated strip and a locking strip. The present invention has the advantages of high efficiency in brick making, good quality and good use effect.

The invention discloses a zoom lens. The zoom lens comprises a focusing lens group with negative focal power, a zoom lens group with positive focal power and a fixed lens group with negative focal power which are sequentially arranged from an object plane to an image plane along an optical axis; the fixed lens group is fixedly arranged, and the focusing lens group and the zoom lens group are movably arranged along an optical axis; the focusing lens group comprises a convex-concave first lens with negative focal power, a biconcave second lens with negative focal power and a convex-concave third lens with positive focal power; the zoom lens group comprises a biconvex fourth lens with positive focal power, a convex-concave fifth lens with positive focal power, a convex-concave sixth lens with negative focal power, a convex-concave / plano-concave seventh lens with positive focal power, a convex-concave eighth lens with negative focal power and a convex-concave ninth lens with positive focal power; the fixed lens group includes a concave-convex tenth lens having a negative refractive power. By the adoption of the technical scheme, the zoom lens has the advantages of being small in size, large in aperture, high in image quality and the like.

The invention provides high-light-transmittance polymethyl methacrylate resin and a preparation method thereof, and belongs to the technical field of high polymer materials. Comprising the following steps: carrying out catalytic cracking on waste polymethyl methacrylate resin, collecting a high-purity methyl methacrylate regenerated monomer I, uniformly mixing the high-purity methyl methacrylate regenerated monomer I with a methyl methacrylate monomer II, a comonomer III, a modifier, an initiator and a chain transfer agent serving as raw materials, and sequentially carrying out primary polymerization, secondary polymerization and tertiary polymerization, so as to obtain the polymethyl methacrylate copolymer. And then inputting the materials into a devolatilization extruder for devolatilization, extrusion molding and granulation to prepare the high-light-transmittance methyl methacrylate resin. The prepared light-transmittance polymethyl methacrylate resin is high in light transmittance, good in toughness and excellent in mechanical property, the application of the light-transmittance polymethyl methacrylate resin is greatly widened, and the light-transmittance polymethyl methacrylate resin has a wide application prospect.

A broadband athermal optical system based on a global surface lens is characterized by the following components arranged sequentially from the outside to the inside along the light propagation direction: a protective window, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a detector photosensitive surface (image plane). The protective window, first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, and ninth lens are coaxially arranged with the detector photosensitive surface (image plane). The optical system receives visible light reflections and short-wave infrared radiation information inherent to the target and background, and converges them onto the detector photosensitive surface for photoelectric conversion. It exhibits high sensitivity and relatively low spatial resolution, enabling target detection, identification, and precise positioning under all-weather and complex meteorological conditions. This invention belongs to the field of optical imaging technology. The optical system exhibits excellent imaging quality, strong light-gathering ability, and good environmental adaptability within a wide spectral and temperature range of 0.4μm to 2.3μm and -50℃ to +70℃. It features simple structure, easy assembly and adjustment, high reliability, low cost, good manufacturability, and high yield. It can be widely used in aerospace optical remote sensing, ground-based target tracking and detection, optical imaging guidance, astronomical observation, industrial multispectral imaging analysis and non-destructive testing, and civil security surveillance, with broad application prospects and significant economic benefits.

The application discloses a kind of based on dual atomic norm minimization multipath high-order QAM signal direct positioning method, first, construct distributed multi-sensor array positioning model under multipath environment, receive signal is obtained;Second, the simplified fourth-order cumulant of each sensor array received signal is calculated, and it is extended to obtain virtual signal;Then, respectively construct semi-positive definite constraint problem, and the dual vector is solved to obtain;Finally, all dual vectors are combined to construct cost function and directly search emitter position, and the position estimation value is obtained.The kind of direct positioning method based on dual atomic norm minimization multipath high-order QAM signal that the application designs can effectively locate emitter.In addition, the method makes full use of the characteristics of high-order QAM signal, can extend array aperture, estimates more emitters.The positioning performance of the application is superior to the traditional spatial smoothing subspace data fusion direct positioning method and discrete fourier transform direct positioning method.

The invention provides a metallocene catalyst and a preparation method and application thereof. The method comprises the following steps: providing a first silicate aqueous solution with the pH value of 9-10 as a base solution; mixing the second silicate aqueous solution, inorganic acid and the base solution, and aging at 70-80 DEG C to obtain a first mixed solution; mixing and reacting the first mixed solution, an alkaline substance and organic alcohol to obtain a second mixed solution; mixing and reacting the second mixed solution, an alkaline substance and organic alcohol to obtain a hydrogel system; mixing the hydrogel system with inorganic acid to obtain acidified gel; performing first post-treatment to obtain a silica gel carrier; carrying out thermal activation on the silica gel carrier, and mixing and reacting with an aluminum alkyl solution to obtain MAO modified silica gel; and mixing the MAO modified silica gel with a metallocene compound, reacting, and carrying out second post-treatment to obtain the metallocene catalyst, wherein the alkaline substance comprises one or a combination of more than two of ammonia water, ammonium carbonate and ammonium bicarbonate. The metallocene catalyst has good catalytic activity.

The invention provides a propylene polymerization sphere-like catalyst component, a solid titanium main catalyst and a preparation method and application of the solid titanium main catalyst, the solid titanium main catalyst comprises titanium halide, magnesium halide and peroxidated benzoate internal electron donors, and under the action of an alkyl aluminum cocatalyst and an organosilicon compound external electron donor, the solid titanium main catalyst is prepared into the sphere-like catalyst component. The catalyst is used for propylene polymerization or copolymerization, shows very high polymerization activity, very good hydrogen regulation sensitivity and stereospecificity, can be used for preparing a green and environment-friendly propylene polymer with high polymer isotacticity, good particle morphology and less fine powder, and can be used for producing a polypropylene product with a high melt index.

The utility model belongs to the technical field of glass fiber reinforced plastic film gluing equipment, specifically relates to a continuous film scraping device, the utility model discloses a film unwinding device, scraper platform frame is established in the export one side of film unwinding device, glue assembly is established in the arbitrary side of scraper platform frame, at least one oven is established in the export one side of scraper platform frame, traction machine is established in the export one side of oven, film unwinding device is used for releasing film roll and outputting film, and film passes through scraper platform frame, glue assembly and oven in proper order, and moves forward under the traction of traction machine. The utility model is used for solving the technical problem of the poor production environment, the easy failure of spray gun and the high cleaning frequency of spray gun of the film of glass fiber reinforced plastic plate in the prior art.

The invention provides a low-light multispectral imaging device under low illumination at night, which is used for solving the problem that spectral characteristic information of a target cannot be acquired by adopting a low-light detection system in a low-illumination environment at night at present. And a visible near-infrared spectrum imager cannot be used for imaging or cannot be used for acquiring a high-contrast image for target detection and identification. According to the low-light-level multispectral imaging device, the electric filter wheel is arranged between the low-light-level imaging lens and the low-light-level detector, hardware external synchronization is arranged between the electric filter wheel and the low-light-level detector, switching of one narrow-band optical filter is completed every time the rotating structure rotates once, switching of one spectral band channel is achieved, and switching of the low-light-level imaging lens and the low-light-level detector is achieved. At the moment, through hardware external synchronization between the electric filter wheel and the low-light detector, the low-light detector synchronously exposes once; according to the invention, through coupling of a low-light imaging technology and a light splitting technology of a plurality of narrow-band optical filters, information of a plurality of spectrum band channels of a detected target is obtained, and efficient detection under low illumination at night is realized.

The present invention relates to the field of catalyst technology, and in particular to a method for synthesizing 2,5-dimethyl-2,4-hexadiene from isobutyraldehyde catalyzed by phosphoric acid-modified Zn / HZSM-5, with isobutylene (IB) / isobutyraldehyde (IBA) as reactants, and a Prince condensation reaction is carried out under the conditions of a phosphoric acid-modified Zn-loaded HZSM-5 molecular sieve catalyst to obtain the obtained product. The invention has the advantages that the process is simple, the energy consumption is low, the safety is high, the cost is low, the pollution is small, and large-scale production is possible; the prepared product 2,5-dimethyl-2,4-hexadiene content can reach 60%, which meets the requirements of industrial products; the reaction specificity is strong, there are no other by-products except water, the catalyst is easy to separate, can be reused, and is environmentally friendly and energy-saving.

The invention relates to the technical field of catalysts, and discloses a macroporous silicon dioxide composite carrier and a preparation method and application thereof.The macroporous silicon dioxide composite carrier contains SiO2 and Al2O3, and the content of SiO2 is 65-90 wt% when the total weight of SiO2 and Al2O3 is 100 wt%; wherein the average pore size of the silicon dioxide composite carrier is 7.6-9.4 nm. The silicon dioxide composite carrier disclosed by the invention has relatively large pore diameter and pore volume, and the catalyst prepared by utilizing the silicon dioxide composite carrier disclosed by the invention has good catalytic performance and longer catalyst service life. The macroporous silicon dioxide composite carrier disclosed by the invention is simple in preparation process and low in price, and has extremely high industrial application and popularization values.

The utility model discloses a large-aperture half-frame lens, which belongs to the technical field of optical lenses and comprises a first lens group, a second lens group, a third lens group and a fourth lens group which are sequentially arranged from an object side to an image side along an optical axis. The focal lengths of all the lens groups meet the following conditional expressions: 1.2 < f (G1) / f (G2-G4) < 3.7; -3.8 < f (G3) / f (G2-G4) <-1.3; 1.6 < f (G1) / f < 4.8. According to the large-aperture half-frame lens, various aberrations of various wave bands are corrected, the central field of view and the edge field of view have enough resolution, the large-aperture half-frame lens has the advantages of being simple in structure, small in size and large in aperture, and the high resolution of imaging with the object distance from infinity to close distance can be achieved.