555results about How to "Reduce liquidity" patented technology

The invention discloses 3D printing low-carbon concrete containing modified recycled aggregate and a micro-powder reinforcer. The 3D printing low-carbon concrete is prepared by the following steps: (1) putting recycled concrete coarse aggregate into sodium or potash water glass, and performing ultrasonic treatment; then separating the coarse aggregate, performing carbonization treatment, and heating the obtained coarse aggregate to obtain the pretreated recycled aggregate. And (2) placing the pretreated recycled aggregate in saturated lime water, and carrying out heating and heat preservation treatment to obtain the modified recycled aggregate. And (3) forming a wet material from the waste cement slurry powder, gamma-C2S powder and water, performing carbonization treatment on the wet material, performing heating treatment, and grinding the obtained solid to obtain the modified regenerated micro-powder enhancer. And (4) uniformly mixing the cement, the modified recycled aggregate, the fine aggregate, the micro-powder enhancer, the water reducing agent and the water to obtain the concrete. The process provided by the invention not only improves the mechanical strength and fluidity of the 3D printing concrete prepared from the recycled concrete aggregate, but also consumes carbon dioxide and reduces carbon emission.

The invention provides an anodic oxidation die-casting aluminum alloy and a preparation method thereof. The anodic oxidation die-casting aluminum alloy comprises the following elements in percentage by mass: 2-4% of Mg element, 0.2-2% of Si element, 1.6-2.4% of Mn element, 0.2-0.3% of Cu element, less than or equal to 2% of Zn element, less than or equal to 0.2% of Fe element, less than or equal to 0.2% of inevitable impurities and the balance of Al, wherein the sum of the mass content of the Mg element and the mass content of the Zn element is 2-4%; the surface chromatic aberration of the anodic oxidation die-casting aluminum alloy is lt; the white brightness L is larger than or equal to 85, the tensile strength ranges from 180 MPa to 210 MPa, the yield strength ranges from 80 MPa to 120 MPa, and the elongation ranges from 3% to 5%. The anodic oxidation die-casting aluminum alloy has excellent flowability and surface glossiness, and is good in surface quality and high in yield.

The invention relates to a crude oil pipeline flow characteristic mining method and system, processing equipment and a storage medium, and the method is characterized in that the method comprises the steps: building a candidate set of a pipeline transportation crude oil flow characteristic representation model of a to-be-tested crude oil pipeline based on a pre-built basic symbol library in combination with a large language model and a symbol regression method; and based on a scoring standard for characterizing the quality of the model, scoring the candidate set of the pipeline transportation crude oil flow characteristic characterization model, and based on a scoring result, optimizing and iterating the structure of the pipeline transportation crude oil flow characteristic characterization model to obtain an optimal pipeline transportation crude oil flow characteristic characterization model of the crude oil pipeline to be tested. According to the method, the flow characteristic model can be rapidly and accurately extracted, the time and cost of experimental data and model construction are greatly reduced, and the method can be widely applied to the field of crude oil pipeline flow characteristic analysis.

The invention relates to frequency converter assembly forming machining equipment, and belongs to the technical field of frequency converter machining. The frequency converter assembly forming machining equipment comprises an electric guide rail and a coating cavity frame, and the electric guide rail is installed on the inner top wall of the coating cavity frame; the spraying processing mechanism is mounted in the coating cavity frame, the surface of the spraying processing mechanism extends to the outer side of the coating cavity frame, and the spraying processing mechanism is mounted below the electric guide rail; according to the electrostatic spraying device, a workpiece can be subjected to relatively uniform spraying operation, in the spraying process, electrostatic paint can be sprayed to the surface of the workpiece at different horizontal heights, and spraying processing can be performed in the direction aligned to the workpiece during spraying at different heights, so that spraying processing of the surface of the workpiece is more uniform, and the spraying efficiency is improved. And the cooling assembly is matched to keep the surface of the workpiece at a relatively low temperature to reduce the fluidity of the coating, so that the sprayed coating is more uniform.

The invention discloses injection molding equipment and an injection molding method thereof, and belongs to the technical field of injection molding. The injection molding equipment comprises a counter, an injection molding machine and a forming mold, one end of the counter is provided with the forming mold, the other end is provided with the injection molding machine, one end of the injection molding machine abuts against the forming mold, the other end is provided with a hopper, and a heating mechanism is arranged between the two ends; an injection molding machine comprises a first injection molding section, a driving section, a pushing section, a second injection molding section and a nozzle which are sequentially connected and communicated, the nozzle abuts against a forming mold, and a hopper is arranged on the first injection molding section; the injection molding equipment has a very good homogenizing effect on molten plastic, can remove insoluble impurities or incompletely molten raw materials contained in fluid, can play a very good filtering role, avoids blockage, prolongs the service life of the injection molding equipment, improves the production efficiency of the injection molding equipment, and protects the precision and stability of the injection molding equipment.

The invention provides a solar cell front protective film, a preparation method thereof and a back contact cell. The solar cell front surface protection film comprises a first cell protection film and a second cell protection film which are stacked in sequence. The first battery protection film is in direct contact with the light receiving surface of the solar battery body; the first battery protection film is prepared on the basis of a polyacrylate adhesive; and the second battery protection film is made based on an organic silicon adhesive. The solar cell front surface protection film has the advantages of low fluidity, high light transmission, scratch resistance, strong adhesion with the surface of the cell, effective protection of the front surface of the cell, good adhesion with a front surface packaging adhesive film, direct lamination with the front surface packaging adhesive film, no need of tearing after use, no reduction of production efficiency, ultraviolet resistance, damp and heat resistance and the like, and is suitable for large-scale production. And through material selection and structural design, the light trapping effect of the solar cell can be improved, and the conversion efficiency of the solar cell and the power of the assembly can be improved.

The invention discloses a glass fiber reinforced nylon material with high alcoholysis resistance, and relates to the technical field of glass fiber reinforced nylon materials. Raw materials of the high-strength and high-toughness composite material comprise the following components in parts by weight: 30-43 parts of PA46, 20-25 parts of PA66, 15-7 parts of PA115, 3-5 parts of bio-based nylon, 20-45 parts of alkali-free glass fibers, 1-3 parts of polyethylene, 0.5-3 parts of an antioxidant, 0.2-3 parts of a heat stabilizer, 0.1-5 parts of a compatilizer, 1-5 parts of a flexibilizer, 0.2-0.5 part of a hydrolysis-resistant agent, 1-2 parts of an ultraviolet light absorber, 0.1-2 parts of a silane coupling agent, 0.1-0.5 part of a nucleating agent, 1-5 parts of hollow glass beads and 3-8 parts of mica. The glass fiber reinforced nylon material is prepared by mixing the raw materials according to the set proportion and sequence, the glass fiber reinforced fiber material with high alcoholysis resistance is finally obtained, a small amount of mica is added into the matrix raw materials, the insulativity and heat resistance of the prepared glass fiber reinforced nylon material are improved to a certain extent, and the service life of the glass fiber reinforced nylon material is prolonged. The range of products made of the material is expanded, the stability of the products is improved, and the products can resist corrosion of strong acid and strong alkali.

The invention discloses a casting system for preparing a nodular cast iron brake disc, and belongs to the technical field of casting, the casting system comprises a casting platform, a casting molding seat is arranged on the casting platform, the casting molding seat is connected with a preparation casting table through a centrifugal rotating assembly, and a plurality of modular casting bodies are uniformly distributed on the upper surface of the preparation casting table; a temperature control device is arranged on the modular casting body, and a regulation and control opening and closing motor is arranged in the preparation casting table and connected with the modular casting body through a joint control assembly. According to the invention, traditional center casting is set into a multi-module modular casting body for sub-module casting, and the fluidity of nodular cast iron casting liquid in the casting process is reduced under the action of centrifugal force, so that the situation that graphite which is not easy to flow is gathered around due to relatively high fluidity is avoided; graphite gradually converges towards the middle under the action of small fluidity, the graphite distribution uniformity of a cast nodular cast iron brake disc casting can be guaranteed, and the quality of the nodular cast iron brake disc is guaranteed.

The invention relates to ultrahigh-strength ultrahigh-toughness concrete and a preparation method thereof, and the process of the preparation method is as follows: designing the mix proportion of concrete slurry based on a close packing theory, and selecting a slurry formula with the fluidity of not less than 180mm and the initial strength of not less than 60MPa as a reference mix proportion; steel fibers are selected as end hook type steel fibers, a wood plate or a steel plate is used for formwork supporting according to the size requirement of the test piece, then a steel fiber cage is laid with the end hook type steel fibers within the supporting range, and the steel fibers are staggered with one another to form a macroscopic steel fiber space framework within the supporting range; preparing slurry according to a standard mixing ratio, then infiltrating the slurry into the built steel fiber space framework, and vibrating after the steel fiber space framework is completely infiltrated with the slurry; and then curing and form removal are performed to obtain the ultrahigh-strength ultrahigh-toughness concrete. The problem of agglomeration effect caused by too high fiber mixing amount is solved, and the unified requirements on the strength and toughness of concrete materials in engineering are met.

The invention discloses an outlet design method for improving vertical shaft outflow and a water inlet and outlet structure based on the outlet design method, and belongs to the technical field of hydraulic engineering. The water inlet and outlet structure comprises a water flow channel, the water flow channel is provided with a vertical section, a water inlet and outlet is formed in the upper end of the vertical section, and flow dividing components are evenly distributed around the water inlet and outlet; the device is characterized in that the upper portion of the flow dividing component is arranged on the periphery above the water inlet and outlet to form a cylindrical retaining wall of a stopping structure, and the upper edge of the cylindrical retaining wall is higher than the dead water level of a reservoir area of the pumped storage power station. According to the vertical shaft type water inlet and outlet structure, the water flow uniformity, flow distribution and trash rack flow velocity distribution are remarkably improved by introducing the buffer water body and optimizing the design, the reverse flow velocity problem is thoroughly eliminated, the operation safety of a power station is improved, the service life of equipment is prolonged, and economic benefits are increased.

The invention relates to the technical field of solar cells, in particular to a perovskite precursor solution, a perovskite solar cell and a preparation method of the perovskite solar cell. The perovskite precursor solution comprises a perovskite material, an additive and an organic solvent; wherein the additive comprises a compound containing pyrrolyl and carboxyl; the perovskite material is of an ABX3 structure, wherein A is a monovalent cation; b is a divalent cation including lead; and X is a monovalent anion. According to the application, the additive can be used for adjusting the film-forming crystallization process of perovskite, carboxyl of the additive and a perovskite material can form an intermediate, film-forming crystallization is delayed, the compactness and uniformity of a thin film are improved, and the film-forming quality is improved; in the large-area coating process, the solution fluidity is low, the time window is lengthened, and the film can grow uniformly; and the pyrrolyl has unsaturated nitrogen atoms, so that free Pb in the perovskite can be passivated, a passivation effect is achieved, and the performance of the device is improved.

The invention discloses an improvement method of sludge soft soil layer shield muck, and belongs to the technical field of shield tunnel construction muck improvement. Metakaolin, blast furnace slag, lignosulfonate and nano silicon dioxide powder are mixed to prepare a mixed raw material, the mixed raw material is pumped into a muck bin, then an alkali-activated solution is pumped into the muck bin, and the mixed raw material is stirred to be uniform; and after mixing and stirring, adding anionic polyacrylamide powder and bentonite, and continuously stirring until a gel system is generated, thereby completing muck improvement. According to the invention, sodium hydroxide and sodium silicate are used as alkali-activated solutions to activate a gel system, blast furnace slag provides a large amount of silicon elements and aluminum elements, and metakaolin contains silicon, aluminum and calcium elements to improve the strength of the gel system; during use, the two raw materials are separated, so that the two raw materials are prevented from reacting in advance before reaching a muck bin to generate gel, and pipeline blockage is avoided; the anionic polyacrylamide and the bentonite are matched, so that the permeability is improved, the drainage of water is facilitated, and the occurrence of spewing is effectively prevented.

The embodiment of the invention provides a display module, a manufacturing method thereof and a display device, relates to the technical field of display, and is used for effectively preventing glue from flowing to a display area. The display module comprises a display panel, the display panel comprises a display area and a first non-display area located on the periphery of the display area and further comprises a substrate and a first film layer located on one side of the substrate, the first film layer comprises an auxiliary sub-part, the auxiliary sub-part is located in the first non-display area, and the auxiliary sub-part comprises a groove or a protrusion.

The invention relates to a self-circulation cooling type shield pump which comprises a pump body and a cooling device, a liquid inlet cavity and a cooling cavity are formed in the pump body, a shielding cover is arranged in the pump body and communicates with the liquid inlet cavity and the cooling cavity, a hollow rotating shaft is rotationally connected to the interior of the shielding cover, and a plurality of impellers are arranged at the two ends of the hollow rotating shaft correspondingly; the cooling device is used for cooling the pump body and comprises a plurality of cooling pipes and a conveying assembly, the cooling pipes are evenly distributed along the outer surface of the pump body, two of the cooling pipes communicate with the liquid inlet cavity, and the conveying assembly is used for conveying liquid in the liquid inlet cavity into the cooling pipes. Liquid in the liquid inlet cavity is conveyed into the multiple cooling pipes through the conveying assembly, the cooling pipes can increase the heat dissipation area of the surface of the pump body, then the liquid flows through the cooling pipes to dissipate heat of the cooling pipes, and cooling and heat dissipation of the outer side of the pump body are enhanced; in the working process of the shield pump, heat dissipation can be conducted on the interior and the exterior of the shield pump, and the heat dissipation performance of the shield pump is improved.

The utility model discloses an anti-puncture rubber tire, which comprises a main tire and an outer-layer rubber tread, the outer-layer rubber tread is positioned on the periphery of the main tire, the main tire is connected with the outer-layer rubber tread through a plurality of groups of spokes, the main tire comprises a tread part, an inner layer is arranged on the inner side surface of the tread part, and an outer layer is arranged on the outer side surface of the tread part. A sealant layer is filled between the inner layer and the inner side surface of the tread part, and the inner layer comprises a dividing strip assembly; the outer-layer rubber tread is in contact with the ground, and a gap formed by the avoiding cavity is formed between the outer-layer rubber tread and the main tire, so that a sharp object is blocked by the outer-layer rubber tread when being punctured into the outer-layer rubber tread and is not easy to puncture into the tread part of the main tire, and the puncture prevention of the main tire is realized; the self-repairing of the tire is realized by the sealant layer depending on the viscosity of the sealant layer; and the sealant layers are filled in the multiple groups of separation cavities in a split manner, so that the influence of the mobility of the sealant layers on the dynamic balance of the tire is reduced.

The invention belongs to the technical field of underwater construction materials, and particularly relates to a self-leveling anti-dispersion underwater bottom sealing material and a preparation method thereof. The self-leveling anti-dispersion underwater bottom sealing material disclosed by the invention is prepared from the following components in parts by weight: 530 to 730 parts of sulphoaluminate cement, 77 to 277 parts of ordinary Portland cement, 84 to 126 parts of fly ash, 870 to 950 parts of fine aggregate, 250 to 278 parts of water, 18 to 23 parts of a water reducing agent, 6 to 10 parts of a flocculating agent, 8 to 12 parts of a retarder, 0.9 to 1.4 parts of a de-foaming agent and 0.1 to 0.4 part of an early strength agent. The self-leveling dispersion-resistant underwater bottom sealing material disclosed by the invention has good fluidity and dispersion resistance.

The invention discloses a method for preparing hydrogel through front-end polymerization-3D printing and front-end polymerization type 3D printing ink, and relates to the technical field of functional polymer material preparation. Ink formed by combining Carbomer 940 particle hydrogel, acrylamide and acrylic acid is prepared on the basis of blocking phase change, the printability of the ink is studied, front-end polymerization and a 3D printing technology are combined, a gel precursor solution and Carbomer 940 serve as main components of the 3D printing ink, a front-end polymerization method is adopted, a gel support of a specific structure and morphology is printed, and the 3D printing ink has the advantages of being simple in preparation process, low in cost and high in practicability. A direct ink writing (DIW) technology is coupled with a front-end polymerization reaction, a polymer three-dimensional model is rapidly prepared with minimum energy input, meanwhile, the front-end end face is spread forwards along with the moving track of a printing needle in the printing process, ink is cured into a polymer in situ through high heat release of the polymerization reaction, and the self-supporting capacity of the model is improved.

The invention discloses a probiotic crystal ball production device and a probiotic crystal ball, and belongs to the field of biological pharmacy, the probiotic crystal ball production device comprises a storage tank, a titration pumping module, a first tank body and a second tank body, the titration pumping module is communicated with the storage tank, the first tank body is provided with a feeding port and a discharging port, and the second tank body is communicated with the storage tank; the outlet end of the titration pumping module penetrates through the feeding hole and extends into the first tank body; a liquid supplementing pipe is further arranged on the first tank body; a feeding pipe is arranged at the top of the second tank body, a discharging pipe is arranged at the bottom of the second tank body, and the feeding pipe is connected with the discharging opening of the first tank body; a spiral generating device used for generating spiral water flow is arranged in the second tank body, and the discharging pipe is further connected with a separating device; primary hardening is achieved through the first tank body, a protective film is formed on the surface of liquid drops, then the semi-hardened liquid drops are driven to rotate through intermolecular acting force and spiral water flow in the second tank body, the liquid drops are gradually hardened into crystal balls, the roundness and production efficiency of the crystal balls can be effectively improved, and the cleanliness of the technological process is guaranteed.

The invention discloses a solid waste-based multifunctional tailing asphalt pavement material and a preparation method thereof, and the pavement material comprises the following components in parts by mass: 4.5-5.5 parts of polyurethane modified asphalt, 45-60 parts of titanate modified iron tailings, 2-5 parts of surface activated copper tailing powder, 20-35 parts of copper tailing sand and 0.5-1.0 part of acetic anhydride modified wollastonite fiber. The high and low temperature performance, the durability and the self-healing performance of the asphalt mixture are comprehensively improved by modifying the solid waste tailing material and the asphalt, and the application range of the asphalt mixture is effectively widened.

The invention discloses rosin type soldering flux for indium-based low-temperature soldering paste and a preparation method of the rosin type soldering flux, and belongs to the technical field of brazing soldering flux. The soldering flux is prepared from the following components in percentage by weight: 40 to 60 percent of modified rosin, 2 to 5 percent of an organic acid activating agent, 0.5 to 2 percent of a halogen-containing compound, 2 to 5 percent of hydrogenated castor oil, 0.1 to 1 percent of benzotriazole, 0.1 to 1 percent of triethanolamine, 0.5 to 2 percent of a surfactant and 0.5 to 2 percent of paraffin oil. And the balance of an organic solvent. The method has the advantages that the prepared soldering flux is good in wettability and excellent in weldability, welding spots are bright and full, the welding void rate is as low as 2.4%, the heat conductivity can reach 43.12 W / mK, the welding spot shear strength can reach 13.45 MPa, and the soldering flux is suitable for low-temperature welding of indium-based brazing filler metal.

The invention discloses a preparation method of a modified asphalt tire-free waterproof coiled material, which is characterized by comprising the following steps: taking the following raw materials in percentage by mass: 41-43% of asphalt, 9-12% of softening oil, 10-11% of tire rubber powder, 1-3% of SBS (Styrene Butadiene Styrene), 3-4% of SBR (Styrene Butadiene Styrene), 1-2% of basalt fiber and 28-34% of filler, mixing and stirring the asphalt and the softening oil, heating to 190-195 DEG C, adding the tire rubber powder, heating to 190-195 DEG C, and stirring for 20-30 minutes, thereby obtaining the modified asphalt tire-free waterproof coiled material. Cooling to 185-190 DEG C, adding SBS and SBR, adding basalt fiber, carrying out heat preservation and stirring, adding a filler, and stirring and mixing to obtain an asphalt composition; and coating one surface of the film with the asphalt composition, and then covering a layer of film, thereby obtaining the modified asphalt tire-free waterproof coiled material. The prepared modified asphalt tire-free waterproof coiled material is good in performance and suitable for buildings to resist external rainwater erosion, prevent underground water leakage and the like.

The two arms of the static Doppler imaging interferometer comprise two pieces of compensation glass, the two pieces of compensation glass are connected to the emergent face of reflected light and the emergent face of projected light of a beam splitting film of a beam splitter respectively, and the two pieces of compensation glass are the first compensation glass and the second compensation glass respectively. The first compensation glass is connected to the incident plane of reflected light of the beam splitting film of the beam splitter, the second compensation glass is connected to the emergent plane of the reflected light of the beam splitting film of the beam splitter, the total reflection mirror and the four-partition reflection mirror are plated at the tail end of the first compensation glass and the tail end of the second compensation glass respectively, and the two pieces of compensation glass are bonded through photosensitive glue. Therefore, the air gap between the two arms of the static Doppler imaging interferometer is eliminated, the stability reduction of the Doppler imaging interferometer caused by the existence of the air gap is effectively avoided, the influence of low air pressure and air flow can be reduced under different environmental conditions, the situation that interference fringes are unstable is avoided, and the stability of the Doppler imaging interferometer is improved. Therefore, the instrument calibration precision and the wind speed detection accuracy are improved.

The invention discloses a construction method and construction equipment for reinforcing a permafrost region roadbed by utilizing powder spraying piles, and relates to the technical field of highway construction, the construction method comprises the following steps: step 1, two rows of cement powder spraying pile waterproof curtains are longitudinally arranged at the slope toe of the existing roadbed through a powder spraying pile drilling machine, the pile diameter of the cement powder spraying piles is 50cm, the pile distance is 40cm, and the pile length is 6m; secondly, in order to achieve water stop and seepage prevention of the powder spraying piles, 10 cm is reserved for the cement powder spraying piles for inter-pile meshing control; a raw powder spraying pile technology is applied to water stopping on the two sides of the plateau frozen soil roadbed, longitudinal cement powder spraying piles are additionally arranged on the two sides of a roadbed slope toe in the original technology, the cement powder spraying piles are used for meshing, the influence of water on the roadbed after underground frozen soil outside the roadbed melts is prevented, and the water stopping and water resisting effects are achieved in the mode of reducing underground water flowing and heat exchange. Meanwhile, dewatering wells are arranged on two sides of the roadbed to reduce moisture in the roadbed. The process enables the roadbed structure to be more stable, and prolongs the service life of the road.

The invention discloses a polyethylene glycol complexing agent as well as a preparation method and application thereof and belongs to the technical field of medicines. The polyethylene glycol complexing agent comprises the following components in percentage by mass: 1-2% of mesenchymal stem cell source exosome modified by miRNA-138-5p, 1-2% of mesenchymal stem cell source exosome modified by miRNA-21, 1-2% of mesenchymal stem cell source exosome modified by lncGm36569, 1-2% of mesenchymal stem cell source exosome modified by mRNA of SNARE family protein, 1-2% of mesenchymal stem cell source exosome modified by mRNA of SNARE family protein and the balance of water. 1-2% of mesenchymal stem cell source exosome modified by mRNA (messenger Ribonucleic Acid) of syntachilin, and the balance of polyethylene glycol. The polyethylene glycol complexing agent disclosed by the invention can reconstruct spinal cord continuity and improve a spinal cord injury microenvironment, so that a neurological function is recovered.

The invention discloses a natto peptide sea cucumber polysaccharide liposome for synergistically improving cardiovascular health and a preparation method and application thereof, belongs to the field of active peptide delivery systems, and aims to solve the stability problem of natto oligopeptide in gastrointestinal digestive tracts. The phytosterol and the vitamin E are filled between phospholipid double layers of the liposome to support a gap between the phospholipid double layers, and the ratio of the phytosterol to the vitamin E is (1-3): 1, so that the natto oligopeptide liposome has the effects that the storage of the natto oligopeptide and the stability of the natto oligopeptide in gastrointestinal and digestive tracts can be improved, the bioavailability of the natto oligopeptide liposome is improved, and the bioavailability of the natto oligopeptide liposome is improved. The traditional Chinese medicine composition has synergistic effects in the aspects of anticoagulation, thrombolysis and blood fat reduction, and has a good cardiovascular protection effect.

The preparation method comprises the following steps: putting vinyl-terminated silicone oil, fumed silica, MQ resin, enol, a fumed silica treating agent and water into a kneading machine according to a certain proportion and sequence, stirring at room temperature for 3 hours, starting vacuum stirring, heating to 120-160 DEG C, stirring at high temperature for 3 hours, and cooling to room temperature to obtain the low-viscosity high-tear-resistance double-component addition type liquid silicone rubber. After the rubber material is cooled, respectively adding a platinum catalyst to prepare a rubber A, and adding hydrogen-containing silicone oil, polyvinyl silicone oil and an inhibitor to prepare a rubber B; the method is simple in process, the prepared AB glue is low in viscosity and can be used for preparing high-hardness and high-tear silicone rubber products, the main raw materials are low-risk substances, the storage period of the prepared AB glue exceeds 12 months, and the AB glue is colorless and transparent in appearance and good in fluidity.

The invention provides a back contact battery, a photovoltaic module and a photovoltaic system. The back contact battery comprises a battery substrate, a plurality of main grids, a plurality of slurry nodes and a plurality of first insulating parts. The battery substrate comprises a tandem connection area and a non-tandem connection area; a plurality of slurry nodes are formed in the cascading area; the first insulating parts are arranged in the serial connection area, the first insulating parts and the main grids are correspondingly arranged, the first insulating parts are arranged in the first direction, the first insulating parts cover the slurry nodes, in the first direction, a first gap is formed between every two adjacent first insulating parts, and part of the main grids are exposed out of the first gaps. Therefore, the first insulating parts corresponding to the main grids are arranged in the serial connection area and cover the slurry nodes, the first gaps are formed between the two adjacent first insulating parts, and the main grids are partially exposed from the first gaps, so that the first insulating parts can be arranged in blocks, the thickness of the first insulating parts is increased, the slurry nodes in the serial connection area are prevented from being conducted with the welding strip, and the reliability of the welding strip is improved. And the reject ratio of the photovoltaic module is reduced.

The invention relates to the technical field of magnesium phosphate cement, and particularly discloses a low-temperature high-fluidity magnesium phosphate cement-based material as well as a preparation method and application thereof. The cement-based material is prepared from the following components in parts by weight: 75 to 90 parts of magnesium phosphate cement, 3 to 8 parts of retarder, 5 to 10 parts of hydroxyapatite, 0.2 to 0.5 part of phenol, 0.5 to 1.0 part of gluconate and 10 to 15 parts of water. Wherein; the modified hydroxyapatite is formed by hydroxyapatite particles with phenol supported on the surface. According to the scheme, the magnesium phosphate cement-based material can keep good fluidity under the conditions of low temperature and low water-binder ratio, good early strength can be formed, and the problem that mechanical properties and working properties of magnesium phosphate cement conflict under the condition of low temperature is effectively solved.

The present invention relates to the field of textile chemicals and high-performance fiber technology, and specifically to a polyacrylonitrile spinning solution, a preparation method thereof, and an application thereof. The preparation method of the polyacrylonitrile spinning solution comprises the following steps: (1) mixing a polyacrylonitrile resin with a first sodium thiocyanate aqueous solution at a temperature of 10 to 25°C, and dispersing and beating at a temperature of 15 to 25°C to form a slurry mixture; (2) mixing the slurry mixture with a second sodium thiocyanate aqueous solution at a temperature of 100 to 140°C, and then high-speed shearing at a temperature of 80 to 90°C to obtain a polyacrylonitrile spinning solution; the polyacrylonitrile resin has a number average particle size of 2 to 9 um, a particle size distribution index of 1.5 to 2.8, and a sedimentation value of 3.0 to 4.2. According to the preparation method of the present invention, the slurry viscosity in the preparation process of the polyacrylonitrile spinning solution is low, the fluidity is good, and it can be used for continuous production, and the prepared polyacrylonitrile spinning solution has a high solid content, a low viscosity, and good extrusion uniformity and stability.

The invention relates to a temperature-responsive flowable concrete admixture which comprises the following raw materials in percentage by mass: 30-50% of a temperature-sensitive polymer material, 2-5% of a cross-linking agent, 3-5% of a water-soluble water reducing agent, 1-3% of a plasticizer and 40-60% of water, wherein the temperature-sensitive high polymer material is selected from one or more of polyvinyl alcohol and sodium polyacrylate. The temperature response type flowable concrete admixture disclosed by the invention can be applied to concrete to realize dynamic adjustment under temperature change, so that the excellent construction performance of the concrete under different environmental conditions is ensured.