49 results about "Tetravalence" patented technology

The invention relates to a composite diaphragm with high ionic conductivity, a composite solid electrolyte and a preparation method thereof. The composite diaphragm is composed of a lithium lanthanum-based fluorine-doped solid electrolyte LLMOF and a base membrane, the chemical general formula of the LLMOF is Li < x > La < y > M < 1 > < z > M < 2 > < w > M < 3 > O < 6 > F, wherein M1 is a tetravalent cation, M2 is a pentavalent cation, and M3 is a hexavalent cation; 1 < x + 3y < 5, 0 < x < = 2, and 1 / 3 < y < 5 / 3; 0 < = z < = 2, 0 < = w < = 2, 0 < = u < = 2, z + w + u = 2; the base membrane is a large-aperture base membrane, and the aperture r is more than or equal to 200nm and less than or equal to 1mu m; the particle size D50 of the LLMOF is 50 nm to 1 [mu] m, and the particle size D50 of the LLMOF is less than or equal to the aperture r of the base film. According to the composite diaphragm disclosed by the invention, the LLMOF solid electrolyte with an ion channel function is introduced, so that efficient conduction of ions is realized; the particle size is matched with that of a large-aperture base membrane, the membrane can be uniformly embedded into membrane holes, a continuous conduction path is constructed, and the ionic conductivity is improved; meanwhile, the composite diaphragm has excellent thermal stability and interface wettability, interface impedance is effectively reduced, and growth of lithium dendrites is inhibited.

The invention relates to the technical field of determination of selenium in seawater, and provides a determination method for dissolved inorganic selenium in seawater. The determination method comprises the following steps: sampling seawater, filtering, adding concentrated hydrochloric acid with the mass concentration greater than or equal to 36%, carrying out a heating reaction at 98-105 DEG C for 12-18 min, cooling, and carrying out a constant volume to prepare a seawater sample to be detected: preparing a plurality of tetravalent selenium standard sample solutions according to gradient concentrations, drawing a standard curve, and testing the seawater sample to be detected. According to the method disclosed by the invention, seawater is treated by concentrated hydrochloric acid, excessive reduction of tetravalent selenium is avoided, a hydride generation-atomic fluorescence method is combined, and a heating reaction process is improved, so that the measurement of the dissolved selenium in the seawater is small in matrix interference, accurate in result, good in precision, high in sensitivity, low in detection limit, high in measurement speed and simple to operate.

This invention discloses a method for precipitation separation and ceramic solidification of divalent strontium and tetravalent uranium in radioactive waste liquid, relating to the field of radioactive waste liquid treatment and disposal. U in high-level radioactive waste liquid is in the form of hexavalent uranyl (UO2). 2+ U exists in the form of hydrogenation catalytic reduction, and the present invention uses hydrogenation catalytic reduction to prepare U. 4+ Sr 2+ and U 4+ ionic radius and Ln 3+ Due to the significant differences, CePO4·0.667H2O cerium phosphate, which has a stronger nuclide-containing capacity, was selected as the co-precipitation enrichment agent for Sr. 2+ and U 4+ Separation precipitant. Inexpensive raw materials such as UO2(NO3)2·6H2O, Sr(C2H3O2)2, NH4H2PO4, and Ce(NO3)3·6H2O are selected. By controlling the Sr... 2+ :U 4+ Ion ratio, reaction time, temperature, pH, and preparation of well-developed Sr crystals 2+ / U 4+ The precipitate of cerium phosphate solid solution with high solid content is avoided by using spark plasma solid-state sintering technology to prevent grain agglomeration and adhesion during high-temperature dehydration and crystal transformation of cerium phosphate. Furthermore, pressure sintering can promote further growth of nanocrystals and promote U... 4+ and Sr 2+ Homogenization within the monazite ceramic solidified body enables a one-step preparation of monazite ceramic solidified body from a lanthanite solid solution.

The invention provides a ferromanganese oxide and a preparation method and application thereof, and belongs to the technical field of secondary batteries. The molecular formula of the ferromanganese oxide is MnxFeyAaBbO3, A is tetravalent metal, B is divalent metal, 0.19 < = x < = 1.8, 0.19 < = y < = 1.8, 0 < = a < = 0.1, 0 < = b < = 0.1, 1.9 < = x + y + 3 / 2a + 3b < = 2.1, and primary particles of the ferromanganese oxide are sheet-shaped. The ferromanganese oxide provided by the invention is of a sheet structure, and more active sites can be provided to support efficient electrochemical reaction, so that the electrochemical performance of the positive electrode material prepared by taking the ferromanganese oxide as the precursor is improved. According to the preparation method of the ferromanganese oxide, part of the ferrous hydroxide precipitate is dissolved under the overalkaline condition, so that the coprecipitation effect is achieved, and the use of a complexing agent is avoided.

The invention provides a positive electrode active material and a preparation method and application thereof, and belongs to the field of batteries. The positive electrode active material provided by the invention comprises layered double hydroxides, and the chemical formula of the layered double hydroxides is [M < 12 + x > M < 23 + y > M < 34 + z > (OH) 2 (x + y + z)] (A < n->) (y + 2z) / n.mH2O, m < 12 + > is a divalent metal cation, M < 23 + > is a trivalent metal cation, and M < 34 + > is a tetravalent metal cation; x is 1-4, y is 0-4, z is 0-4, and (y + z) is 1-4; m = 1-2, and n = 1-3; the interlayer spacing of the layered double hydroxide is equal to that of the positive electrode active material, the material structure stability in the oxidation-reduction reaction process can be maintained, the proper interlayer spacing is beneficial to reversible storage migration and intercalation / deintercalation of carbonate ions, and the electrochemical oxidation-reduction reaction and directional storage and conversion of charges are achieved.

The invention discloses a nuclear waste containing material and a preparation method and application thereof, and belongs to the technical field of nuclear waste treatment.The nuclear waste containing material is characterized in that site-specific doping of trivalent or tetravalent nuclides is achieved through trivalent or tetravalent nuclides, namely, A-site doping is conducted on Lu4Hf3O12 through Z < 3 + > or B-site doping is conducted on Lu4Hf3O12 through Z < 4 + >, the solid solubility of the A-site Z < 3 + > is as high as 25 mol%, and the solid solubility of the B-site Z < 4 + > is as high as 40 mol%; compared with a traditional pyrochlore-based material, the nuclide containing capacity is remarkably improved, the relative density of the nuclear waste containing material is larger than or equal to 95%, and the grain size can reach 1-5 microns; the prepared nuclear waste containing material is excellent in leaching resistance, and the leaching rate of the nuclear waste containing material is 2-4 orders of magnitude lower than that of a conventional curing material; the nuclear waste containing material prepared by the invention has better long-term chemical stability, and the mass loss rate of a highly-doped sample after long-term leaching is reduced by 21% compared with that of a low-doped sample.

The present invention relates to a process for preparing a zeolite having a CHA-type framework structure comprising X2O3 and YO2 wherein X is a trivalent element and Y is a tetravalent element, comprising (1) preparing a synthesis mixture comprising: (A) a source of X2O3, (B) a source of YO2, and (C) a source of organic structure directing agent (OSDA), the source comprises a biquaternary ammonium cation of formula (I) or a combination of biquaternary ammonium cations of formula (R1R2R3) N + (CH2) nN + (R4R5R6) (I) as defined in the claims, and (2) subjecting the synthesis mixture to crystallization conditions to form a zeolite having a CHA-type framework structure. The invention also relates to the zeolite having a CHA-type framework structure obtained by the method and to the use of the zeolite in a catalyst for the selective catalytic reduction of nitrogen oxides.

To provide a piezoelectric thin film exhibiting a large performance index expressed as -e31,f / ε0εr.SOLUTION: A piezoelectric thin film contains a metal oxide with a perovskite structure. The metal oxide comprises a first component and a second component. The first component is either component α alone, or both component α and component β. The component α is a BiEATRO3 containing one or more trivalent elements EATR. One or more trivalent elements EATR contain Fe. The component β is Bi(EAD0.5EATE0.5)O3, containing one or more divalent elements EAD and one or more tetravalent elements EATE. The second component is BiEBO3, which contains a plurality of elements EB. The plurality of elements EB contain divalent elements. Furthermore, the plurality of elements EB includes at least one element selected from the group consisting of trivalent elements, tetravalent elements, pentavalent elements, and hexavalent elements. The average valence of the plurality of elements EB is 3.SELECTED DRAWING: None

The invention provides a high-entropy alloy pole piece and a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The high-entropy alloy pole piece comprises a bottom lining and a high-entropy alloy deposited on the bottom lining, the chemical general formula of the high-entropy alloy is Ni20MaNbXcYdZe, the high-entropy alloy comprises rare earth metal or / and scattered metal, a, b, c, d and e respectively represent atomic percentages of corresponding metal elements, a is larger than or equal to 5 and smaller than or equal to 35, c is larger than or equal to 5 and smaller than or equal to 35, and e is larger than or equal to 5 and smaller than or equal to 35. 10 < = b < = 40; 6 < = c < = 35; 0.1 < = d < = 10; 0 < = e < = 10; a + b + c + d + e = 80; m is a monovalent metal, N is a divalent metal, X is a trivalent La series metal, Y is a tetravalent metal, and Z is a pentavalent metal. The structural stability and the mechanical performance of the prepared high-entropy alloy pole piece are improved, the lithium nucleation overpotential can be effectively reduced through regulation and control over the multivalent rare earth and the scattered metal, lithium ions are promoted to be evenly deposited on the surface of a negative electrode, and then growth and volume expansion of lithium dendrites are inhibited. The prepared high-entropy alloy negative electrode can be used for prolonging the cycle life and improving the rate capability of a lithium metal battery.

The invention relates to the technical field of nuclear material analysis, in particular to a plutonium solution specific activity determination method and application, and the plutonium solution specific activity determination method comprises the following steps: taking a plutonium solution with known specific activity A1 as a standard solution, determining the liquid flash counting rate of the standard solution, and recording the liquid flash counting rate as C1; obtaining a second-order conductance spectrum of the standard solution by using an ultraviolet-visible absorption spectrum method, determining the peak area of a characteristic absorption peak of tetravalent plutonium in the second-order conductance spectrum of the standard solution, and recording the peak area as S1; measuring the liquid flash counting rate of the to-be-measured solution, and recording the liquid flash counting rate as C2; obtaining a second-order conductance spectrum of the to-be-detected solution by using an ultraviolet-visible absorption spectrometry, determining the peak area of a characteristic absorption peak of tetravalent plutonium in the second-order conductance spectrum of the to-be-detected solution, and recording the peak area as S2; and calculating the specific activity A2 of the solution to be detected according to the following formula. According to the method, liquid scintillation counting and ultraviolet-visible spectrophotometry are combined, so that combination of activity response and concentration response is realized, and acquisition of isotope composition of a plutonium solution to be detected and complex sample pretreatment are not needed.

The invention relates to a multi-element rare earth doped HfO2 thermal barrier coating material and a preparation method thereof, and belongs to the technical field of thermal protection coatings. The thermal barrier coating material is prepared from Gd2O3, Yb2O3, Y2O3 and HfO2, wherein the Gd2O3, the Yb2O3, the Y2O3 and the HfO2 are The thermal barrier coating material is of a single c-phase structure. The raw material powder is ground to obtain mixed powder, the mixed powder is sintered after being ground and compacted, and finally the coating material is obtained through grinding and screening. The rare earth elements Gd < 3 + >, Yb < 3 + > and Y < 3 + > with large ion radiuses are doped to replace tetravalent Hf4 < + > crystal lattice positions, a large number of point defects are formed in crystal lattices, and a large number of oxygen vacancies are generated due to the charge balance effect, so that phonon scattering heat transfer is remarkably enhanced, and the multi-element rare earth doped HfO2 thermal barrier coating material has low thermal conductivity.

A niobium-containing oxide powder according to the present invention satisfies formula (I).　(I) AaTi(2-p-q-r)(MV (0.5+v)MIII (0.5-v))p(MV (0.67+w)MII (0.33-w))qMIV rNb(14-s)M1 sO(39±t) (In the formula, A is at least one element selected from the group that consists of Li and Na, M1 is selected from the group that consists of MV, (MIV (0.5+w)MVI (0.5-w)), (MVI (0.67+w)MIII (0.33-w)), and (MVI (0.75+w)MII (0.25-w)), each MII is independently at least one divalent metal element, each MIII is independently at least one trivalent metal element, each MIV is independently at least one tetravalent metal element, each MV is independently at least one pentavalent metal element, each MVI is independently at least one hexavalent metal element, 0≤a≤6, -0.05≤v≤0.05, -0.05≤w≤0.05, 0≤p<2, 0≤q<2, 0≤r<2, 0<p+q+r<2, 0≤s<14, and 0≤t≤1, provided that at least two of p, q, and r are not 0.)

The invention discloses a high-purity vanadium oxide compound for vanadium electrolyte and a preparation method thereof, and the preparation method of the high-purity vanadium oxide compound comprises the following steps: (1) mixing a pentavalent vanadium solution with a first reducing agent to obtain a tetravalent vanadium solution; (2) the tetravalent vanadium solution is subjected to extraction and reverse extraction treatment, and tetravalent vanadium reverse extraction liquid is obtained; (3) neutralizing the tetravalent vanadium reextraction liquid with ammonia water, and separating out tetravalent vanadium hydrate; (4) mixing the tetravalent vanadium hydrate with a second reducing agent and reacting; the second reducing agent is selected from at least one of hydrogen, methane, coal gas and carbon powder. According to the method, the high-purity vanadium oxide composed of V (III) and V (IV) can be rapidly and accurately prepared, the requirement for equipment is not high, and operation is easy.

The invention discloses a method for recovering Se and TeO2 from tellurium-containing crude selenium refining slag, which comprises the following steps of: crushing the tellurium-containing crude selenium refining slag, performing temperature-controlled roasting, decomposing nitrate, and oxidizing tellurium into a high valence state; the roasting slag and a reducing agent are mixed and heated under the vacuum condition, so that the selenium compound is reduced into elemental Se and volatilized, and meanwhile high-valence tellurium is reduced into tetravalent tellurium salt residues; crushing the reduced product, performing water-soluble leaching, and filtering to obtain a solution containing selenite and tellurite and TeO2 precipitate; adding acid into the leaching filtrate to hydrolyze the tellurite salt into TeO2 precipitate, and filtering and separating to obtain TeO2 and selenium-containing filtrate; finally, acid and a reducing agent are added into the selenium-containing filtrate, and selenite is reduced into elemental Se precipitate. The method realizes efficient separation and recovery of selenium and tellurium, is reasonable in process flow and high in recovery rate, and has a good application prospect.

This invention provides an O3-phase layered oxide material, its preparation method, and its application. The preparation method includes: providing a mixed slurry containing a sodium source, a nickel source, an iron source, a manganese source, a tin source, an M source, and a first metal oxide; centrifugally spray-drying this slurry to obtain a precursor powder; mixing the precursor powder with a second metal oxide; and solid-state sintering in an oxygen-containing atmosphere to obtain the O3-phase layered oxide material. The first metal oxide includes copper oxide and / or magnesium oxide; the second metal oxide contains a high-valence, strongly bonded cation with a valence greater than or equal to tetravalent, and the bond energy formed with the cation by the cation is above 600 kJ / mol; the M source is one or more combinations of zinc, aluminum, titanium, and antimony. This O3-phase layered oxide material, based on the synergistic effect of oxide doping with high-valence, strongly bonded cations and the high-entropy effect, can improve the discharge plateau, rate performance, and long-cycle stability of sodium-ion batteries.

The application belongs to the technical field of inorganic functional material preparation, and particularly relates to pure-phase vanadium dioxide powder and a preparation method and application thereof. The application makes the precursor system simultaneously contain pentavalent vanadium species and tetravalent vanadium species through partial reduction treatment, so that the average valence of vanadium gradually approaches the target valence of vanadium in VO2, and meanwhile, reaction space for further reduction, hydrolysis, condensation and crystal growth in a subsequent hydrothermal process is reserved. The partial reduction mode can avoid excessive complexation, rapid nucleation and organic residue caused by excessive citric acid, relieve the reduction and hydrolysis process, and reduce the risk of local excessive reduction and out-of-control oxygen content in a subsequent vacuum annealing process. The obtained VO2(M) powder has obvious heat-induced phase change endothermic and exothermic peaks and high phase change enthalpy, indicating that the crystal phase purity is high and the phase change process is sufficient, and the powder is suitable for the fields of thermochromic, infrared regulation, intelligent window and infrared camouflage.

The present application discloses a red phosphor, and a preparation method and an application thereof and relates to the field of luminescent material technology. The chemical composition of the red phosphor is A2M(1-x)F6:xMn4+. The A is selected from at least one of alkali metal elements, and the M is selected from at least one of IVA group elements or a Ti element and a value range of the x is 0<x≤0.05. The red phosphor is granular; and a concentration of tetravalent manganese ions in a radial direction from a center of a particle of the red phosphor to a surface of the particle of the red phosphor decreases gradually. In the present application, the concentration of the activator Mn4+ in a radial direction from the center of the particle of the red phosphor to its surface is set to a descending gradient distribution to buffer the phosphor powder from the erosion of water vapor, thereby improving its anti-aging performance and prolonging the service life.

The invention provides a light-emitting material and a preparation method thereof, a wavelength conversion element and a light-emitting device, and belongs to the technical field of light-emitting materials. The luminescent material comprises an inorganic substance, and the element composition of the inorganic substance at least comprises a basic element composition or a basic element composition and a selective element composition; the basic elements at least comprise Ba, an element A, an element D, N, O and an element RE; the selected element composition at least comprises an element E; a comprises at least one of an element M and a Zn element, and M comprises at least one of alkaline earth metal elements; d comprises at least one of tetravalent metal elements; rE comprises at least one of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er and Tm; e comprises at least one of S, C, Cl, F and Br; the inorganic substance has a crystal structure, belongs to an orthogonal structure, and is crystallized in a space group Pcca. The luminescent material provided by the invention has excellent long-term aging resistance.

Disclosed herein is a process for preparing a zeolite material having an AFX framework structure including X2O3 and YO2 via interzeolite conversion, the process including (1) providing a mixture including a first zeolite material having a non-FAU framework structure including X2O3 and YO2 and an organic structure directing agent selected from the group consisting of diquaternary ammonium cation containing compounds, and (2) heating the mixture from (1) to form a second zeolite material having an AFX framework structure including X2O3 and YO2, wherein X is a trivalent element and Y is a tetravalent element, and where the organic structure directing agent is not 1,4-bis(1,4-diazabicyclo[2.2.2]octane)butyl dihydroxide when the first material zeolite has a CHA framework structure. Further disclosed herein is the zeolite material having an AFX framework structure as obtainable or obtained from the process, and a method of using the same as a catalytically active material.

The present invention relates to a high-silica FAU molecular sieve with a high proportion of exposed acid sites, a method for preparing the same by microstructure assembly, and an application thereof. The molecular sieve adsorbent has a FAU molecular sieve configuration, and its chemical composition molar ratio is Al2O3: mSiO2: nM2O. The elemental composition contains a relatively large amount of tetravalent element Si and a relatively small amount of trivalent element Al, and the molar ratio of oxides (m = SiO2 / Al2O3) is in the range of 5-20. This kind of molecular sieve is synthesized by using an initial gel prepared from crown ether, alkali, water, a silicon source and an aluminum source, adjusting the charge density of the double template agent, and assembling different cage structures of the FAU molecular sieve, while realizing the regulation of the proportion of exposed acid sites. Compared with commercial molecular sieves such as Beta and NaY, the high-silica FAU molecular sieve with a high proportion of exposed acid sites in the present invention can be applied to the adsorption and separation of phenolic substances in the liquid phase system, especially preferentially adsorbing a large amount of phenol in the phenol isooctane solution and preferentially adsorbing 2,5-dimethylphenol in the 2,5-dimethylphenol aqueous solution.

This ferromagnetic ferroelectric material has ferroelectricity and ferromagnetism, and contains a compound represented by any one of general formulae (1) to (3). Bi1-xA2+ xFe1-xM4+ xO3 ... (1) (In the formula, A is Mg, Ca, or Sr, and M is a 4d element or a 5d element that can form a tetravalent ion. x satisfies 0.02 ≤ x ≤ 0.15.) Bi1-xA+ xFe1-xM5+ xO3 ... (2) (In the formula, A is Na or K, and M is a 4d element or a 5d element that can form a pentavalent ion. x satisfies 0.02 ≤ x ≤ 0.15.) Bi1-2xA2+ 2xFe1-xM5+ xO3 ... (3) (In the formula, A is Mg, Ca, or Sr, and M is a 4d element or a 5d element that can form a pentavalent ion. x satisfies 0.02 ≤ x ≤ 0.15.)

This invention relates to the field of luminescent materials technology, and more specifically, to molybdenum-doped fully inorganic hole-ordered double perovskites, their preparation methods, and applications. The first aspect of this invention provides three types of molybdenum-doped fully inorganic hole-ordered double perovskites: tetravalent molybdenum-doped, pentavalent molybdenum-doped, and co-doped with tetravalent and pentavalent molybdenum, with the chemical formulas Cs₂Sn₂, respectively. 1‑x Cl6:xMo 4+ Cs2Sn 1‑y (O y Cl 6‑y ):yMo 5+ and Cs2Sn 1‑a‑b (O b Cl 6‑b ):aMo 4+ ,bMo 5+ The second aspect of this invention provides methods for preparing three types of molybdenum-doped fully inorganic hole-ordered double perovskites: tetravalent molybdenum-doped, pentavalent molybdenum-doped, and co-doped with tetravalent and pentavalent molybdenum. The third aspect provides applications of these three types of molybdenum-doped fully inorganic hole-ordered double perovskites in product testing, anti-counterfeiting, safety monitoring, non-destructive analysis, light-emitting LEDs, solar cells, temperature detectors, multispectral imaging, ultra-wideband light sources, or broadband photodetectors. The fourth aspect provides an optoelectronic device in which the luminescent material is this molybdenum-doped fully inorganic hole-ordered double perovskite.

The invention provides an Hf and Ce co-doped yttrium lutetium silicate scintillation crystal as well as a preparation method and application thereof, and relates to the technical field of scintillation crystal material preparation. The chemical formula of the yttrium lutetium silicate scintillation crystal is (Hf < x > Ce < y > Y < z > Lu < 1-x-y-z >) < 2 > SiO < 5 >, x is less than or equal to 0.1, 0lt; y is less than or equal to 0.05, 0lt; z is less than or equal to 0.2, and is prepared by co-doping tetravalent Hf ions (Hf < 4 + >) in the lutetium yttrium silicate Ce-doped crystal, the introduction of Hf < 4 + > competes with oxygen vacancies and shallow electron traps in the crystal to capture electrons, and the concentration of the electron traps is effectively reduced, so that the fluorescence and flicker decay time of the crystal is effectively shortened, and the response speed of the crystal to radiation is improved.

The invention belongs to the field of water electrolysis, and particularly relates to an amorphous / crystal RuO2 / WOx-SO4 < 2-> composite material, a PEM water electrolysis device, preparation of the PEM water electrolysis device and application of the PEM water electrolysis device in water electrolysis hydrogen production, and the amorphous / crystal RuO2 / WOx-SO4 < 2-> composite material comprises multivalent WOx and amorphous / crystal RuO2; and modifying SO4 < 2-> anchored on the amorphous / crystal RuO2; the multivalent WOx is an oxide of positive tetravalent tungsten, positive pentavalent tungsten and positive hexavalent tungsten; the amorphous / crystal RuO2 comprises a rutile-phase RuO2 core and amorphous RuO2 coated on the surface of the RuO2 core. The invention innovatively provides a material with a special physicochemical structure, and the material can accidentally adapt to the acidic OER catalysis requirement based on the combined control of components and the physicochemical structure, can obtain excellent catalytic activity and stability, and optimizes the utilization rate of noble metal Ru.

A scintillation compound can include a rare earth silicate. The rare-earth silicate may be lutetium yttrium orthosilicate. The rare-earth silicate may be doped with Ce. The rare-earth silicate doped with Ce may include a rare-earth element in a tetravalent state at a concentration of at least approximately 10 ppm atomic of the scintillation compound.

The invention discloses a TiO2-doped ZnO wave-absorbing material and a preparation method thereof, and relates to the technical field of wave-absorbing materials. The chemical formula of the wave-absorbing material is Zn1-xTixO1-delta, x is greater than or equal to 0 and less than or equal to 0.2, and delta represents oxygen deficiency caused by Ti < 4 + > substitution; the doping mass ratio of TiO2 in the wave-absorbing material is 0 to 20 percent. The preparation method comprises the following steps: (1) preparing materials; (2) primary ball milling; (3); drying for the first time; (4) presintering; (5) crushing; (6) performing ball milling for the second time; (7) drying for the second time; (8) granulating and forming; (9) discharging glue; and (10) sintering. The dielectric loss of ZnO is improved through tetravalent Ti ion doping and introduction of an additional interface and dipole polarization, the wave-absorbing material with excellent wave-absorbing performance is obtained, and meanwhile the preparation method is simple, low in cost and suitable for mass production.

The invention belongs to the field of materials, and relates to an amorphous high-entropy fluoride positive electrode material and a preparation method and application thereof. The chemical formula of the amorphous high-entropy fluoride positive electrode material is AxMyM'zF2x + 3y + 4z, A is a divalent metal elements with different compositions, M is b trivalent metal elements with different compositions, and M'is c tetravalent metal elements with different compositions; 0 < = a < = 5, 0 < = b < = 5, 0 < = c < = 5, a + b + c = N and N > = 5; the subscript x corresponding to each A is 1 / 2N < = x < = (N + 1) / 2N, the subscript y corresponding to each M is 1 / 2N < = y < = (N + 1) / 2N, the subscript z corresponding to each M'is 1 / 2N < = z < = (N + 1) / 2N, and the sum of the total subscripts of A, M and M 'is 1.

The embodiment of the invention discloses a method for preparing metal zirconium from zirconium-hafnium alloy through valence state regulation and control. Comprising the following steps: adding tetravalent hafnium salt into a zirconium-hafnium alloy raw material as a valence regulator to obtain a reaction raw material; adding chloride eutectic salt into the reaction raw materials as a reaction medium; under set conditions, metal hafnium in the zirconium-hafnium alloy reacts with tetravalent hafnium salt to generate divalent hafnium ions; putting a reaction product system into a high-temperature-resistant metal crucible, and carrying out electrolysis under set conditions by taking a zirconium rod as an anode, a high-purity zirconium rod as a cathode and chloride eutectic salt in the reaction product system as electrolyte; in the electrolysis process, the metal zirconium of the anode is oxidized into zirconium ions to enter the electrolyte, the zirconium ions in the electrolyte migrate to the cathode to be separated out and precipitated into nuclear-grade metal zirconium with the purity being 99.95% or above, and metal hafnium is left in the electrolyte in the form of ions.

The invention relates to the technical field of spent fuel post-treatment analysis, and provides a method for determining tetravalent neptunium in an organic phase, which comprises the following steps: preparing organic phase standard solutions of tetravalent neptunium with a series of concentrations, and determining the absorption spectrum of the standard solutions; performing second derivative treatment on the absorption spectrum of the standard solution to obtain a second-order guide spectrum of the standard solution; establishing a quantitative correction relation between the peak area of a characteristic absorption peak and the concentration of the tetravalent neptunium according to the second-order guide spectrum of the standard solution; measuring the absorption spectrum of the organic phase solution to be measured; performing second derivative treatment on the absorption spectrum of the to-be-detected solution to obtain a second-order guide spectrum of the to-be-detected solution; and substituting the peak area of the second-order guide spectrum of the to-be-detected solution at the characteristic absorption peak into the quantitative correction relation, and calculating to obtain the concentration of the tetravalent neptunium in the to-be-detected solution. According to the method, the concentration of the tetravalent neptunium in an organic phase system with relatively high acidity (3.0-8.0 mol / L) can be directly measured.