50results about How to "Solve the problem of uneven mixing" patented technology

The invention discloses a high strength sprayed concrete for high ground temperature tunnels and a preparation method thereof. The concrete comprises following raw materials: cement, fly ash, slag powder, sand, coarse aggregate, glass beads, PVA fibers, steel fibers, modified rubber, a water reducer, a setting accelerator, and water. Low melting point water-soluble PVA fibers are adopted, after concrete reaches the melting point of the PVA fibers, fibers are melted, tunnels are formed, thus water steam in the concrete can be conveniently dissipated through the tunnels, the steam pressure in the concrete is reduced, the risk of bursting is reduced, at the same time, the melted water-soluble PVA fibers can largely enhance the inner cohesive force of concrete, and the cracking of a cement face is avoided. Through the cooperation of all raw materials, the prepared concrete has the characteristics of low heat conductivity coefficient, good anti-permeability, high interfacial bond strength,and little long-term strength loss. The long-term strength of concrete after spraying is largely improved. The cracking of high ground temperature concrete is avoided.

The invention discloses a method for preparing niobium-tungsten binary complex carbide nano powder. The method comprises the following steps: S1, putting tungstate into a fluorine-niobium acid solution, further adding a surfactant till the pH value is 9-12, leaving to stand, aging, and filtering; S2, collecting niobium-tungsten precursor precipitate, and washing; S3, drying washed precipitate, and grinding and screening so as to obtain niobium-tungsten precursor complex powder; S4, performing reduction treatment on the niobium-tungsten precursor complex powder so as to obtain niobium oxide-tungsten complex powder; S5, selecting actual carbon addition coefficients; S6, adding carbon, and uniformly mixing with raw material powder; S7, putting uniformly mixed powder in a graphite boat or a ceramic boat loosely, performing carbonization treatment, and cooling and discharging from a furnace after treatment is completed; and S8, grinding and screening the discharged niobium-tungsten complex carbide, thereby obtaining the niobium-tungsten binary complex carbide powder. By adopting the method, mixing of niobium-tungsten binary complex carbide of a molecular grade is achieved, and the niobium-tungsten binary complex carbide powder is not only fine in granule, but also very high in chemical uniformity and purity.

The invention discloses thermal conductive plastic applying a modified carbon material, and a preparation method thereof. The thermal conductive plastic comprises the following components in percentage by mass: the modified carbon material, magnesium oxide, boron nitride, nylon 66, a polyanionic type high polymer, a dispersing agent, and a couplant, wherein the modified carbon material comprises the following components in parts by weight: a base carbon material, a surfactant, a polycationic type high polymer, and a couplant; the modified carbon material is prepared by the steps of: mixing water, the base carbon material, sodium chloride, the surfactant and the couplant according to a proportion and then performing ultrasonic treatment, slowly adding the polycationic type high polymer during the ultrasonic process, continuously performing ultrasonic treatment and then stirring for 20-24h, filtering and drying. According to the thermal conductive plastic applying the modified carbon material, and the preparation method thereof, the problem that the materials inside the plastic are mixed unevenly can be effectively solved, and the compatibility of the carbon material can be improved greatly; the dispersity of the whole material mixture can be enhanced, and plugging is difficult in the extrusion process; the synthetic technology is simple, and the conditions of high temperature, a strongly corrosive environment and the like are not required.

The invention discloses a preparation method of a lithium iron phosphate anode material. The method comprises the steps of ultrasonically dispersing iron phosphate and lithium sources into deionized water, adding chitosan, cane sugar, pepsin, erepsin or trypsin, fully stirring and uniformly mixing, and placing into a sealed container. Relatively high CO2 concentration is kept in the sealed container. Under the regulation of biological organic large molecules, Li2CO3 crystals uniformly grow by taking the surfaces of iron phosphate particles as basal bodies, and a little of Mg<2+> can be added into a solution to control the growth of the Li2CO3 crystals. After reacting for several days, turbid liquid is filtered and washed for several times and placed into a drying box for drying to prepare a lithium iron phosphate precursor, and sintering is performed under gas shield to obtain the lithium iron phosphate anode material. According to the preparation method, the problem that the energy consumption is relatively large due to stirring and ball-milling in a conventional lithium iron phosphate material preparation process is solved; meanwhile, lithium carbonate prepared through biomimetic synthesis uniformly attaches to the peripheries of the iron phosphate particles, and the problem of nonuniform raw material mixing possibly existing in the preparation process of lithium iron phosphate is solved.

The invention relates to an active core silver solder for soldering ceramics and a preparation method thereof, and the active core silver solder comprises two parts, namely a core part and an outer layer, wherein the core part is composed of an active alloy containing active elements and the outer layer is composed of a silver alloy. The active core silver solder comprises the following main components by weight percent: 2-6% of the active alloy comprising three elements, namely Ti, Zr and Hf, wherein the active alloy contains 0.1-5wt% of the Zr, 0-3wt% of the Hr and the balance of the Ti; and 94-98% of the silver alloy comprising the elements of Ag, Cu and Ge, wherein the silver alloy contains 66-72wt% of the Ag, 26-27.9wt% of the Cu and 0.1-8wt% of the Ge. The threadlike active core silver solder can be directly obtained by adopting a method of wrapping an active core at the interior by extrusion through semi-molten metal. Compared with the characteristic of low melting point of thesolder of domestic like products, the preparation process is high in production efficiency and a new way is opened for manufacturing the solder which is difficult to machine and form due to brittle intermetallic compounding.