716results about How to "Short holding time" patented technology

The invention discloses a grouting connection construction method which is used for connecting vertical reinforcements of an assembled concrete structure. The grouting connection construction method includes the steps: firstly, embedding a plurality of grouting connection devices at one end of a precast concrete unit to be connected in advance; secondly, lifting the precast concrete unit and then manufacturing a grouting box dam; thirdly, grouting horizontal gaps and then grouting the grouting connection devices. The grouting connection devices are connected with connection reinforcements extending out of a lower unit. Plugging grouting of the horizontal gaps and grouting of the grouting connection devices can be performed within the same day, so that the mounting efficiency of the precast concrete unit is greatly improved, the grouting connection construction method can be implemented in a subzero temperature environment even in winter, construction difficulty is reduced, and working efficiency is improved.

The invention discloses a vacuum brazing technology method between copper and stainless steel dissimilar metal water connector, comprising processing each part of the water connectior, controling the processing precision and component assembly clearance; washing the part of water connectior; assembling water connections and putting in special fixture. Put the fixture in vacuum brazing furnace and carry out braze welding according to the following brazing technology: 1) take 35 minutes to make the furnace temperature to rise to 650 DEG C at a uniform speed; 2) continue to preserve heat for 20 minutes; 3) rise the furnace temperature at a uniform speed to 890 DEG C in 20minutes; 4) continue to preserve the heat for 20 minutes; 5) then rise the furnace temperature to 970 DEG C+-10 DEG C at a uniform speed in 15 minutes; 6) Continue to preserve heat for 5 minutes; 7) then stop heating and cool naturally; 8) on the next day take out the water connector from the fixture; 9) carry out the acceptance test by using the ultrasonic automatic testing device. The technical problem that the annular gap of the water connector is not fully filled and can be corroded is solved; the invention has the advantages of reliable method and high production efficiency, and can effectively improve the qualified rate of the products.

The embodiment of the invention discloses a preparation method for lithium-based glass ceramic for dental prosthesis. The preparation method comprises: filling glass powder which is prepared in advance into a die, wherein the grain size of the glass powder is less than 50 microns; and pressing and moulding the powder under 50-500 Mpa to obtain a lithium-based glass ceramic blank; putting the lithium-based glass ceramic blank into a heating device to raise the temperature to 500-600 DEG C for first-time sintering at a temperature raising rate of 1-30 DEG C/min, wherein the insulating time of the first-time sintering is 10-120 minutes; and carrying out furnace cooling to prepare the lithium-based glass ceramic. Compared with lithium disilicate glass ceramic prepared in the prior art, the lithium-based glass ceramic prepared by the technical scheme is relatively low in strength, low in hardness, better in processability, more easy to mould and suitable for a processing room and a chair-side repairing system.

The present invention discloses a high purity nano-scale magnesium-aluminum spinel synthesis method, which comprises the following steps: 1) uniformly mixing light burning magnesium oxide and boehmite according to an amount ratio of MgO to Al2O3 of 1:1, and carrying out ball milling and drying molding to obtain a billet sample sheet; and 2) pre-burning the billet sample sheet for 1 h at a temperature of 500 DEG C, then heating to a temperature of 850-1500 DEG C, carrying out thermal insulation for 2-3 h, and cooling to a room temperature to obtain the high purity nano-scale magnesium-aluminum spinel. According to the present invention, the raw material combination is the light burning magnesium oxide and the boehmite, a sintering reaction activity of the newborn gamma-Al2O3 obtained after boehmite pre-burning is greater than a sintering reaction activity of the general gamma-Al2O3, and the nano-scale material has a huge specific surface area and surface activity so as to reduce a sintering temperature of the magnesium-aluminum spinel, shorten a thermal insulation time, and reduce energy consumption, wherein the sintered spinel content can be up to 97.9%; and the method is applicable for industrial production, and meets requirements of energy saving and emission reduction.

The invention provides a process for nanometer composite powder zinc impregnation processing method, which comprises metal member pretreatment, powder zinc impregnation processing and metal member post-treatment. The powder zinc impregnation processing comprises formulation of nano composite powder zinc impregnation agent, a zinc impregnation procedure and a cooling down separation process.

The invention relates to a manufacturing technology of a hot work die steel forge piece. The manufacturing technology comprises the steps including forging, high-temperature normalization, high-temperature tempering, ultrafine solution treatment, spheroidizing and sampling inspection. Through the procedures and related heat treatment, chemical components in the hot work die steel forge piece tendto be consistent, the structure inheritance is effectively cut off, and accordingly the purposes of refining grains and homogenizing structures are achieved. After spheroidizing, a spherical pearlitewith fine-particle-shaped carbide evenly distributed on a ferrite base body is obtained. An excellent organization structure is provided for final heat treatment.

The invention discloses Cu2O ultra-fine nano-particles and self-assembly nanospheres as well as a preparation method thereof, relating to the preparation method of the nano-particles. A whole reaction mixed liquid is divided into two phases through regulating the proportion of each substance in a reaction system, wherein one phase contains metal salt while the other phase contains a reducing agent. The metal salt is released to the phase containing the reducing agent, and contacted with the reducing agent at a part close to the interface of two phases to carry out reduction reaction, and the release action and a protecting agent in the reaction system commonly act in the whole reaction system so as to achieve the aim of controlling the appearances and the sizes of the product Cu2O ultra-fine nano-particles. The Cu2O ultra-fine nano-particles can be prepared by using the release method; if the reaction mixed liquid containing the Cu2O ultra-fine nano-particles continuously keeps the temperature for certain time at certain temperature, Cu2O self-assembly nanospheres with larger particle sizes formed by self-assembling the Cu2O ultra-fine nano-particles are prepared due to the Ostwald maturating action.

The invention relates to a preparation method of transparent yttria ceramics with high optical quality, which belongs to the field of preparation of transparent ceramics. The preparation method comprises the following steps: adding anhydrous ethanol to the mixture of commercial high-purity Y2O3 powder serving as a raw material, ZrO2 serving as a sintering additive and zirconia balls serving as a grinding medium, and carrying out mixing and ball milling for 3-30 hours; adding a crylic acid salt dispersant in the powder to prepare water-based slurry of Y2O3, and adopting a porous resin mold or porous alumina ceramic mold to achieve slip casting; and finally, carrying out pressureless sintering in a vacuum or hydrogen atmosphere furnace to obtain the transparent yttria ceramics with high optical quality. The transmission rate of the Y2O3 transparent ceramics with thickness of 2mm is up to 81.3% at the wavelength of 1100nm. The invention has the advantages of simple process, low cost and no pollution, and is easy to control, and the transparent yttria ceramics with high optical quality can be prepared at lower sintering temperature in shorter holding time.

The invention discloses a ferrite-based ceramic composite material as well as a preparation method and application thereof. The composite material is composed of ferrite, a carbon nanotube and a ceramic material, wherein the ferrite and the ceramic material are cladded on the tube wall of the carbon nanotube, and the ceramic material is one or several kinds of aluminum oxide, aluminum nitride, and silicon nitride. The three phases of materials, namely, the ferrite, the carbon nanotube and the ceramic, are compounded to make the advantages and disadvantages of all phases of materials complementary, so that the electrical conductance of the composite material is increased, the impedance matching performance of the composite material is improved, the wave absorption performance of the composite material is made adjustable, the structure and function integration of the ferrite-based ceramic material is realized, and thus, the application range of the composite material in the high-tech field is expanded. In addition, the powder of the composite material is prepared by adopting a coprecipitation hydrothermal method and is further prepared into a block material by adopting a microwave sintering method, and the ferrite-based ceramic composite material has the advantages that all phases are dispersed uniformly, the densification degree of the sintered material is high, the production cost is low, and the large-scale industrialization is easy to realize.

The invention discloses a deep water pipeline composite polyurethane elastomer heat insulation layer casting molding device. A subsection machining and integral assembly mode is adopted in a die, heating temperature control devices are arranged corresponding to subsection assemblies in subsections, and heating oil passages are arranged opposite; a positioning structure and a sealing structure arearranged in the parting surface of the die; and the die is provided with a die opening device, a die closing and an inclination device controlled by a hydraulic system. The device realizes mechanicaloperation of casting molding of a product, and has practical structure and strong operability; by adopting subsection machining in the die, the machining difficulty and the machining cost are reduced, and the machining precision and the machining quality are improved; and meanwhile, three sets of heating devices are used corresponding to three sections of assemblies, so that the heating temperature difference is reduced, the quality of the cast product is improved, automatic control of the temperature of the casting die can be realized, the heat insulation time of the polyurethane heat insulation layer in the die is shortened, and the service efficiency of the casting die is improved.

The invention relates to the field of metal material heat treatment, in particular to hot-work die steel and a heat treatment method thereof. The heat treatment method comprises the following steps of1), heating the die steel at rate of 80-180 DEG C/min to 1100D EG C-1300 DEG C, and carrying out heat preservation for 3-10 minutes; 2), quenching the die steel after heat preservation in a quenchingmedium; and 3), tempering the quenched die steel. According to the method, the obtained hot-work die steel grains are not coarsening, the carbides are more dispersed and distributed, the tempering stability is good, the high temperature strength at the same hardness after processing is greatly improved, the thermal fatigue performance of the die steel is improved, after the heat treatment is performed to the same hardness, the impact toughness of the die steel after the new process is slightly higher than that of the traditional process, the method greatly shortens the heating and heat preservation time in the quenching process, and can achieve the effects of saving time and cost for small-batch and small-sized products.

The present invention relates to a method for producing chemical fibre pulp by using plant fibre as raw material. Said method includes the following several steps: raw material treatment, making the treated raw material undergo the processes of rubbing and extruding, cooking, washing, removing sand and bleaching treatment. It is characterized by that in the preparation process of said chemical fibre pulp a screw extruding machine and a rubbing-extruding machine are adopted.

The invention relates to a solid electrolyte material and a preparation method thereof. The chemical composition is Li<6+x>Al<y>(La<z>A<3-z>)(Zr<n>G<2-n>)O<12+alpha>wt% D, wherein A is selected from at least one of Ca, Sr, Y and Ba; G is selected from at least one of Ti, Nb, Ta, Sb and V; D is selected from at least one of SiO2, Bi2O3, B2O3, CeO2, ZnO, CuO, MnO2, Co2O3 and SnO2; x is smaller than or equal to 2 and greater than or equal to 0; y is smaller than or equal to 1 and greater than or equal to 0; z is smaller than or equal to 3 and greater than or equal to 2; n is smaller than or equal to 2 and greater than or equal to 1; and alpha is smaller than or equal to 3 and greater than or equal to 0. The safety problems that a lithium-ion liquid battery leaks liquid and is flammable, explosive and the like are solved; battery miniaturization and product shape diversification are facilitated; the process route is simple; massive production is easily to implement; a sample is low in sintering temperature and short in heat preservation time; volatilization of lithium ions is reduced; and the sintering cost is greatly reduced.

The invention relates to a low viscosity UV/moisture dual-curing polyurethane hot melt adhesive and a preparation method thereof, belonging to the technical field of photocuring adhesives. The low viscosity UV/moisture dual-curing polyurethane hot melt adhesive comprises the following components in parts by weight: 95-97 parts of UV/moisture dual-curing polyester polyether polyurethane, 1-3 partsof free radical photoinitiator, 0.25-2 parts of cationic photoinitiator, 0.25-1 part of photosensitizer, 0.06-0.35 part of polyurethane catalyst, 0.01-0.02 part of water reducing agent, and 0.05-0.2 part of antioxidant. The hot melt adhesive can be used for the bonding of opaque substrates. The viscosity of the adhesive at the sizing temperature 110 DEG C is in the range of 2000-2500 mPa.s, the viscosity is low, the construction is convenient, the initial viscosity is strong, the positioning is fast, the holding time is shortened, even the holding pressure is not needed. The hot melt adhesivedoes not contain small molecular active diluent and is environmentally friendly. The preparation process is simple, easy to operate and suitable for industrial production.

The invention discloses a preparation method of an anode material for a lithium ion battery, which comprises the following steps of: mixing titanium dioxide with lithium carbonate to be ball-milled evenly, carrying out heat preservation for 10-180 minutes at the temperature of 750-850 DEG C and cooling to obtain lithium titanate; and mixing the lithium titanate with a solid-state nitrogen source compound to be calcined with the protection of protective gas, and obtaining the anode material for the lithium ion battery after reaction. In the step of preparing the lithium titanate, the time for heat preservation of raw materials at high temperature is greatly shortened, the aggregation of material particles caused by long-time ignition is avoided, the particle size of the lithium titanate is greatly reduced, and the modification area of TiN after the lithium titanate is nitrided is increased, so that the conductivity performance of the prepared anode material for the lithium ion battery is improved. In addition, due to the reduction of the particle size of the lithium titanate, the migration distance of lithium ions in a charge-discharge process of the lithium ion battery is reduced, and thus the large current charge-discharge performance of the anode material for the lithium ion battery is improved.