327 results about "Hexagonal phase" patented technology

Uncoated particles of reversed cubic phase or reversed hexagonal phase material containing an active disposed within are provided. The uncoated particles have an ionic charge that is sufficient to stabilize them in dispersion in a liquid, e.g. a polar solvent. The active that is disposed within the particles may be, for example, a pharmaceutical or nutriceutical compound.

The invention belongs to the technical field of semiconductor oxide gas sensors, and particularly relates to a gas sensor based on graded porous WO3 microspheres and a preparation method thereof. A gas-sensitive coating in the gas sensor based on the graded porous WO3 microspheres is prepared from the graded porous WO3 microspheres, the graded porous WO3 microspheres have single hexagonal-phase crystal structures and are uniform in body size and good in individual dispersity, the diameter of the graded porous WO3 microspheres is 3-5 micrometers, and each graded porous WO3 microsphere is formed by assembling WO3 nanorods with the diameter being at the nanoscale and has a large specific surface area and high porosity. According to the preparation method, hydro-thermal synthesis is performed in the presence of a mixing assistant, and the graded porous WO3 microspheres are obtained and assembled to form the finished product. The gas sensor based on the graded porous WO3 microspheres has the advantages of being low in working temperature, high in sensitivity, low in energy consumption, high in selectivity and the like.

The invention is a method for growing crackles family-III nitride on a silicon substrate, using stress compensating buffer layer to grow crackles a family-III nitride film on the silicon substrate, and comprising the steps of: 1) firstly depositing an about 20 nanometer thick aluminized high-temperature aluminum nitride buffer layer on a monocrystalline silicon substrate and then depositing a layer of hexagonal-phase matter (such as low-temperature aluminum nitride, gallium aluminum nitride or boron nitride) whose lattice constant is far less than that of the family-III nitride and thus forming a buffer layer with stress compensating function; and 2) adding in an activating agent to make a stress compensating layer easy to form at low temperature and simultaneously the surface smooth and the crystal quality high; 3) because the lattice constant of the predeposited hexagonal-phase matter is less than that of the family-III nitride, able to introduce pressure stress into the family-III nitride film grown on the predeposited hexagonal-phase matter so as to compensate drawing stress caused by mismatching with the silicon substrate.

Hard coatings and methods of making the hard coatings comprising aluminum titanium nitride which are usable on cutting tools are disclosed. The coatings include at least one aluminum titanium nitride layer having between about 0 and about 15 weight percent hexagonal phase and a composition of (Al_xTi_1-x)N, where x is in the range of about 0.53 to about 0.58 moles.

The invention discloses fluorescent salix mongolica regenerated cellulose fibers and a preparation method thereof. The preparation method comprises the following steps: peeling off salix mongolica, crushing, sieving, drying and cooling to prepare salix mongolica wood powder; extracting salix mongolica cellulose by adopting an ethanol-acid mixed solution; treating the salix mongolica cellulose by processes of steaming, bleaching and the like to prepare salix mongolica pulp; filtering, decompressing and de-foaming water-soluble up-conversion nano particles and the salix mongolica cellulose to obtain a spinning solution which is uniformly mixed; and spinning the spinning solution by a condensation bath, drafting and molding, refining and drying to obtain the fluorescent salix mongolica regenerated cellulose fibers. A preparation process of the water-soluble up-conversion nano particles comprises the following steps: firstly, synthesizing hexagonal-phase up-conversion luminous nano particles UCNPs by adopting a high-temperature thermal decomposition method; treating the UCNPs with nitrosonium tetrafluoroborate NOBF4, and replacing oleic acid molecules on the surface; finally, reacting with a hydrophilic hyperbranched polymer to obtain the water-soluble up-conversion nano particles. According to the fluorescent salix mongolica regenerated cellulose fibers, the water-soluble up-conversion nano particles and the salix mongolica regenerated cellulose are used as raw materials and are subjected to efficient blending and wet-process spinning to prepare the regenerated cellulose fibers with the excellent fluorescent performance.

The invention relates to a semiconductor meso pore material of multivariate metal oxide, which has a general formula of AxByOz, wherein, A is equal to Ca, Sr, Ba, Na, K, La, Fe, Ni, Zn, Al, Si and so on, and B is equal to Ti, Ta, W, Fe, Co, Al, Si, In, Bi and so on; the condition that A is equal to Si while B is equal to Al is not included; specific surface area of the meso pore material is 10 to1,000 m2g-1; a pore wall of the meso pore is in a crystal state and adjustable aperture is between 2 nm to 50 nm; a pore channel shapes like a worm, cubic phase and hexagonal phase and so on. The material is synthesized through the following steps: 1) inorganic metal salt solution is prepared; 2) metal alkoxide salt solution is prepared; 3) the two solutions are mixed and stirred to obtain transparent or translucent solution; 4) certain amount of embedded segment surfactant is added into the solution and then the mixture is stirred until clarified; 5) the solution with the surfactant which isobtained in the step 4) is parched to obtain xerogel; 6) the xerogel is thermally processed; 7) the obtained xerogel is roasted; 8) impurities of the roasted sample are removed in acid or alkali solution and then the aperture is regulated.

The invention relates to a mesoporous silicon dioxide molecular sieve and a preparation method thereof. The method comprises the following synthesis steps: 1), mixing a nonionic surfactant, a silicon source and water in a molar ratio of (0.01-0.1): (300-500): (1-3), regulating the pH value of the solution to 1.0 to 3.0 with an acid, and stirring the solution at 20 to 80 DEG C for 1 to 3 hours to form a sol mixture; 2) stirring the sol mixture obtained by the step 1 at room temperature, adding an alkaline buffer solution and regulating the pH value of the solution to 5 to 7.5 to obtain a white silicon dioxide precipitate; and 3) roasting the precipitate obtained by the step 2 at 500 to 600 DEG C for 3 to 5 hours to obtain a white mesoporous silicon dioxide material. The white mesoporous silicon dioxide material has an order hexagonal phase structure, a local short range order hexagonal phase structure, a multilayer onion-like structure, a worm-like structure or a foam-like hollow vesica structure. The method for synthesizing the mesoporous silicon dioxide molecular sieve of the invention is a real green biomimic synthesis method. The application of the method can promote the industrial production of like materials.

The invention provides a method for preparing graphene by epitaxy of an ultrathin hexagonal phase silicon carbide film on an insulating substrate. The method is characterized by comprising the following steps: step one, taking the insulating substrate; step two, carrying out high-temperature etching pretreatement on the insulating substrate by hydrogen to remove surface scratch and other deficiencies so as to obtain flat surface; step three, carrying out high-temperature nitrogen treatment on the insulating substrate to activate the epitaxial surface so as to ensure that subsequent silicon carbide can be easily adhered on the surface of the substrate and maintain the same crystallographic orientation relationship with the substrate; step four, extending the hexagonal phase monocrystal silicon carbide on the insulating substrate; and step five, vaporizing silicon ions in the silicon carbide to complete preparation of the graphene on the insulating substrate.

A transparent yttrium aluminum garnet precursor composition is provided that includes a plurality of calcined particles of yttrium aluminum oxide having a mean particle domain size of between 10 and 200 nanometers and a predominant hexagonal crystal structure. High levels of YAG transparency are obtained for large YAG articles through control of the aluminum:yttrium atomic ratio to 1:06±0.001 and limiting impurity loadings to less than 100 ppm. The composition is calcined at a temperature between 700° Celsius and 900° Celsius to remove organic additives to yield a predominant metastable hexagonal phase yttrium aluminum oxide nanoparticulate having an atomic ratio of aluminum: yttrium of 1:0.6±0.001. With dispersion in an organic binder and a translucent YAG article is formed having a transmittance at a wavelength of 1064 nanometers of greater than 75%. The translucent YAG article is characterized by an average domain size of less than 1 micron and having a density of at least 99% and inclusions present at less than 2 surface area percent. The ability of a batch of yttrium aluminum oxide nanoparticles to serve as a transparent YAG precursor includes collecting an X-ray fluorescence spectrum from a plurality of aluminum oxide nanoparticles having a predominant crystal structure other than garnet to yield an A1:Y raw integrated peak intensity ratio. The nanoparticles are sintered to yield a predominant garnet phase and a secondary phase and optionally isostatic pressing during sintering. By using only precursor nanoparticles with a standard deviation of ±0.003 in the peak ratio exceptionally high transparency YAG is reproducibly produced.

The invention belongs to the technical field of a nano up-conversion luminescent material, in particular relates to a preparation method for a small-sized NaYF4 nano substrate material with a hexagonal phase by inducement with rare earth nano crystal nucleus. In the method, rare earth ions are doped in the NaYF4 nano substrate material so as to obtain a nano material with a low up-conversion luminescence threshold and high luminescence strength. In the method, the small-sized beta-NaYF4 nano substrate material is generated by inducement with a hydrothermal (solvent) process in the presence ofrare earth fluoride nano crystal nucleus, wherein the size of the particle is from 20nm to 200nm, and distribution of the size is even. According to the invention, a preparation method of the small-sized NaYF4 nano substrate material with the hexagonal phase is expanded, and the problem that the NaYF4 nano substrate material, especially water-soluble NaYF4 nano substrate material is difficultly generated at low temperature, is solved. By using the nano up-conversion luminescent material, the demand on biological fluorescent identification probes and disease diagnosis and treatment materials is met, and a foundation is established for the practicable application of the up-conversion luminescent material.

The invention relates to the technical field of inorganic nano-material preparation, and discloses an upconversion nanocrystalline/titanium dioxide composite nanomaterial and a preparation method thereof. The chemical formula of the upconversion nanocrystalline/titanium dioxide composite nanomaterial is NaYF4:Yb,Tm@SiO2@TiO2, wherein '@' refers to coating. The preparation method of the upconversion nanocrystalline/titanium dioxide composite nanomaterial comprises the following steps: A, using hexagonal phase NaYF4:Yb,Tm nanocrystalline as a nucleus, and coating the surface with a layer of silicon dioxide shell; B, uniformly coating the surface of the silicon dioxide shell with a titanium dioxide shell layer. The preparation method is simple in technology and easy to operate, the prepared upconversion nanocrystalline/titanium dioxide composite nanomaterial is small in size which is even within 50 nm, the structure is uniform, the upconversion efficiency is high, the utilization efficiency of TiO2 on infrared lights can be obviously improved, and the photocatalytic performance is greatly improved.

The invention discloses an elementary substance Bi nano-structured material and a preparation method and an application thereof. The elementary substance Bi nano-structured material is a flower-shaped nano particle comprising platy hexagonal phase elementary substances Bi which are used as structural units. The preparation method of the elementary substance Bi nano-structured material comprises the following steps of: dissolving a surfactant, hydrazine hydrate and a bismuth salt in water, and preparing into turbid liquid; and reacting the turbid liquid at the temperature of 80 to 120 DEG C for 18 to 30 hours, and centrifuging the turbid liquid to obtain the elementary substance Bi nano-structured material. The elementary substance Bi nano-structured material can be used for preparing Bi modified electrodes. The obtained Bi modified electrodes can be used for detecting heavy metal ions in an aqueous solution, and the detection limit can reach 1 x 10<-4> grams per liter.

The invention relates to high-temperature enhanced upconversion fluorescence type nanocrystal for temperature sensing. The high-temperature enhanced upconversion fluorescence type nanocrystal for temperature sensing refers to hexagonal phase sodium yttrium tetrafluoride spherical or rod-shaped nanocrystal with the average diameter or length of 15-50nm, and rare earth Yb<3+> and Tm<3+> are co-doped into the nanocrystal. The nanometer powder is heated from room temperature to a temperature of 220 DEG C, the crystal structure and the surface structure are kept invariable, the index of the upconversion fluorescence intensity under laser excitation of 980nm is enhanced in an exponent manner along with the temperature, and the nanocrystal can be repeatedly used after temperature reduction. According to relation analysis between a fluorescence intensity ratio in ground state transition from Tm<3+> thermal coupling energy levels <3>F3 and <3>H4 and the temperature, temperature measurement can be performed.

The invention provides a preparation method of NaY(98-X)% F4:X%Yb, 2%Er@NaDyF4 in a core-shell structure and relates to a preparation method of up-conversion reflecting material. The invention solves the technical problems that luminescent center of the existing magnetic fluorescent material can be easily influenced by a high-energy group and the up-conversion luminescent efficiency and luminescent intensity are reduced. The preparation method provided by the invention comprises the following steps of: adding DyCl3.6H2O into a mixture of oleic acid and octadecene, heating up to 160 DEG C to form uniform light yellow solution, cooling, adding normal hexane solution, stirring, then heating up, insulating, cooling, adding absolute methanol solution of NH4F and NaOH, standing still, heating and insulating in an argon atmosphere, and then heating up and insulating, cooling, washing, and centrifuging, thus obtaining the NaY(98-X)% F4:X%Yb, 2%Er@NaDyF4 in the core-shell structure. The NaY(98-X)% F4:X%Yb, 2%Er@NaDyF4 in the core-shell structure is of a hexagonal phase structure, the luminescent center of the NaY(98-X)% F4:X%Yb, 2%Er@NaDyF4 in the core-shell structure is not influenced by the high-energy group, and up-conversion luminescent efficiency is improved, so that the luminescent intensity is greatly improved.

A NaGdF4 multifunctional fluorescent label nano-material based on europium ion dual-mode luminescence. In the invention, Tm<3+> (Yb <3+>) and Eu<3+> are respectively mixed into cores and shell bodies of NaGdF4 nanometer crystals, and thus europium ion dual-mode luminescence is realized in monodisperse hexagonal phase NaGdF4 nanometer crystals. Through co-sensitization of Tm<3+> and Yb <3+> in the cores and the advantages of core-shell structures, strong europium ion red up-conversion luminescence is realized under near-infrared light of 980nm, and strong europium ion red down-conversion luminescence is realized under ultraviolet light of 273nm. The monodispersed NaGdF4 nanometer crystals which have the core-shell structures and can generate europium ion up-conversion luminescence and europium ion down-conversion luminescence can be utilized as a multifunctional fluorescent label nano-material after being treated by surface functionalization. The NaGdF4 fluorescent label nano-material with core-shell structures comprises NaGdF4 comprising 0 to 50 molar percent Yb <3+> and 0 to 10 molar percent Tm<3+>, and NaGdF4 comprising 0 to 50 molar percent Eu<3+>.

The invention relates to a hexagonal-phase MoO2 nanosphere stacked micron hollow sphere and a preparation method and application thereof. The preparation method of the micron hollow sphere comprises the step of carrying out a hydrothermal synthesis on MoO3 powder and diethylenetriamine, wherein the mass ratio of MoO3 powder to diethylenetriamine is (3-10):1. According to the invention, the preparation method of the hexagonal-phase MoO2 nanosphere stacked micron hollow sphere is proposed for the first time, operation is simple and easy, and the prepared micron hollow sphere is good in property and can be massively synthesized; and the hexagonal-phase MoO2 nanosphere stacked micron hollow sphere prepared by the method in the invention has good circulation property and high specific capacity, and the specific capacity of the prepared micron hollow sphere still can reach 250mAhg<-1> after thirty-five-time circulation under the condition that current density is 0.5Ag<-1>.

The invention discloses an in-water-phase monodisperse sodium yttrium tetrafluoride ytterbium-and-erbium-doped multi-color upconversion luminescent nanoparticle and a preparation method thereof, belonging to the field of multifunctional application-oriented inorganic advanced nano materials. According to the method, a product is synthesized in one step through a hydrothermal method, and a sodium yttrium tetrafluoride nanoparticle capable of emitting light of different colors can be obtained by regulating the amount of NaF; and the particle which is uniform in size and is in morphology of cubic phases or hexagonal phases can be obtained through simple condition change. The sodium yttrium tetrafluoride multi-color luminescent nanoparticle can stably exist in water for long time, has excellent biocompatibility and can be directly used in hydrophilic systems of biosensors, cell imaging, magnetic resonance imaging, disease diagnosis and treatment and the like. The cost of raw materials is low, less pollution is caused to the environment, and the method is simple, so that the sodium yttrium tetrafluoride multi-color luminescent nanoparticle has wide application prospects in the field of biology and the fields such as thin-film materials, luminescent devices, anti-counterfeiting materials and the like. It is worth mentioning that the material has been successfully used in the field of cell imaging.

A hard coating layer on a cutting tool includes at least a Ti and Al complex nitride or carbonitride layer and has an average layer thickness of 1 to 20 μm. In a case where a composition of the complex nitride or carbonitride layer is expressed by: (Ti_1-xAl_x)(C_yN_1-y), a content ratio x and a content ratio y satisfy 0.60≦x≦0.95 and 0≦y≦0.005, where x and y are in atomic ratio. Crystal grains constituting the complex nitride or carbonitride layer include cubic phase crystal grains and hexagonal phase crystal grains. An area ratio occupied by the cubic phase crystal grains is 30-80%. An average grain width W is 0.05-1.0 μm. An average aspect ratio A of the crystal grains with the cubic grain structure is 5 or less. A periodic content ratio change of Ti and Al in (Ti_1-xAl_x)(C_yN_1-y) exists in each of the cubic phase crystal grains.

The invention relates to preparation and high-efficiency hydrogen production of a novel surface plasma enhanced high-efficiency photocatalytic water splitting composite catalyst Au/CdX (X refers to S, Se and the like). The Au/Cd core-shell structure nanocrystalline consists of Au particles serving as a core and a CdX semiconductor serving as a shell layer, wherein the size of the Au particles is 20-45nm; the CdX shell layer is a single crystalline layer of 2-12nm; and the crystal form is a hexagonal phase of wurtzite. The preparation method comprises the following steps: adding a precursor into hydrosol of the Au/Ag nanoparticles to be converted into Au/AgX; adding a cadmium salt and a phosphine ligand, reacting at the temperature of 50 to 80 DEG C to generate the Au/CdX catalyst. The photocatalytic water splitting hydrogen production efficiency of the catalyst is 20-30mol/g/h and is higher than that of pure CdS quantum dots of the same mass by over 1000 times. The water solubility is high, the inverted phase is not needed during the test, the operating device is simplified, and the time is shortened. Meanwhile, the material utilization rate is improved, the synthesis condition is mild, and the catalyst is environmentally friendly, feasible and low in cost and has wide application prospects in the field of photocatalysis.

The invention provides a lighting unit comprising a light source, configured to generate light source light and a luminescent material, configured to convert at least part of the light source light into luminescent material light, wherein the light source comprises a light emitting diode (LED) and wherein the luminescent material comprises a phosphor comprising M₂AX₆ doped with tetravalent manganese, wherein M comprises monovalent cations, at least comprising potassium and rubidium, wherein A comprises a tetravalent cation, at least comprising silicon, wherein X comprises a monovalent anion, at least comprising fluorine, and wherein M₂AX₆ has the hexagonal phase.

This invention discloses hollow CdS, CdSe or CdTe nanoring, which has hexagonal structure. The outer diagonal length is 200-260 nm, and the inner diagonal length is 50-70 nm. The hollow CdS or CdSe nanoring has a hexagonal phase, while the hollow CdTe nanoring has a cubic phase. The CdS, CdSe or CdTe nanoring can be used to fabricate biosensors or microelectronics. This invention also discloses a method for preparing hollow CdS, CdSe or CdTe nanoring.

The invention discloses an electrostatic spinning fluorescent PVA nanofiber membrane and a preparation method of the electrostatic spinning fluorescent PVA nanofiber membrane. The preparation method includes the steps that a high-temperature thermal decomposition method is adopted to synthesize hexagonal-phase up-conversion luminescence nano-particles (UCNPs), nitrosonium tetrafluoroborate (NOBF4) is used for treating the UCNPs to substitute oleic acid molecules on the surface of the UCNPs, finally the substitution product reacts with a hydrophilic hyperbranched polymer to obtain water-soluble up-conversion nano-particles, the water-soluble up-conversion nano-particles are added to a polyvinyl alcohol (PVA) spinning solution and ultrasonically and evenly mixed with the PVA spinning solution, and the electrostatic spinning fluorescent PVA nanofiber membrane is obtained through an electrostatic spinning method. The adopted water-soluble up-conversion nano-particles are excellent in fluorescence property and good in water solubility and compatibility with a PVA water solution and have wide application prospects in the fluorescent falsification-preventing field.

The invention provides a surface coating cutting tool which coats a (Til-XA1X)(CYN1-Y) layer formed by hexagonal phase and cubic phase mixed organization forming a film by means of chemical vapor deposition by taking A1 (CH3) as reaction gases on a matrix surface formed by WC-base cemented carbide, TiCN-base metal ceramics, cBN-base ultrahigh pressure sintered body, wherein X and Y are 0.60<=X<=0.95 and 0.0005<=Y<=0.005 by means of atomic ratio. When an inclined angle formed by the normal line of the surface (0001) of a particle of the hexagonal phase relative to the normal line direction of the surface of the matrix is detected, the zoning of the inclined angle in the range of 2-12 degrees has peak value and the degree proportion occupied in the zoning of the inclined angle is more than 40%, preferably, the average aspect ratio Alpha c of the cubic phase is less than 2, the average particle width Omega c is less than 0.3 [mu]m, and moreover, the average aspect ratio Alpha h of the hexagonal phase is more than 2, and the average particle width Omega h is in the range of 0.1-2 [mu]m.