84 results about "Chromium doping" patented technology

The invention relates to a preparation method of a chromium-doped ferrous alloy wave-absorbing material. The preparation method comprises the following steps: mixing raw materials: Fe, Nd and Cr according to a certain atom ratio, melting the metals in an arc furnace; then sealing the alloy sample in a vacuum quartz glass tube, then placing the sealed quartz glass tube in a high-temperature environment to carry out a further homogenization treatment, quenching, taking out the alloy sample, mechanically and primarily grinding the alloy sample in a mortar, then transferring the alloy powder to a stainless steel ball-milling tank, carrying out high-energy ball milling under the protection of gasoline, after a while, pouring out the gasoline, taking out the alloy sample powder, drying the powder in the air so as to obtain the alloy micropowder wave-absorbing material.

A photonics data storage system according to the present invention is described comprising a storage material, a data recording/storage apparatus for recording information in this storage material, and an addressing/data reading apparatus for reading the recorded information from this storage material. The photonics data storage system encodes data in the storage medium by an interferometric recording process. The storage medium is composed of a polypeptide material. The polypeptide material comprises a solution of chromium-doped collagen, in which solution α and β chains are predominantly present in proportions such that an α/β ratio is greater than 1.

The invention relates to a preparation method of transparent tetravalent chromium-doped yttrium aluminum garnet ceramics. The preparation method comprises the following steps: weighing raw material powder according to a stoichiometric ratio of a to-be-prepared ceramic component structural formula (Al1-xCrx)5CayY3-yO12 (x is not smaller than 0.001 and not larger than 0.01, and y is not smaller than 10x and not larger than 40x); adding a sintering aid and a charge compensating agent; mixing by ball-milling to obtain a slurry material; drying and sieving the slurry material and then molding to obtain a biscuit; calcining to remove volatile impurities; sintering the biscuit in vacuum at the temperature of 1730 to 1850 DEG C for 4 to 30 hours; subsequently annealing in air at the temperature of 1300 to 1550 DEG C for 10 to 25 hours to obtain compact Cr<4+>:YAG transparent ceramics. The Cr<4+>:YAG transparent ceramics prepared by the method disclosed by the invention are high in compactness, good in uniformity, free of segregation, reasonable in grain graduation distribution, free of abnormal grain growth, free of grain interior and intergranular pores and high in penetration rate, and have the conditions for being a laser gain medium.

The present invention relates to a fiber having a core of crystal fiber doped with chromium and a glass cladding. The fiber has a gain bandwidth of more than 300 nm including 1.3 mm to 1.6 mm in optical communication, and can be used as light source, optical amplifier and tunable laser when being applied for optical fiber communication. The present invention also relates to a method of making the fiber. First, a chromium doped crystal fiber is grown by laser-heated pedestal growth (LHPG). Then, the crystal fiber is cladded with a glass cladding by codrawing laser-heated pedestal growth (CDLHPG). Because it is a high temperature manufacture process, the cladding manufactured by this method is denser than that by evaporation technique, and can endure relative high damage threshold power for the pumping light.

A chemical formula of a manganese-chromium-doped zinc tungstate luminescent material is ZnWO4:xMn4+, yCr3+ wherein 0.003<=x<=0.145, and 0.003<=y<=0.066. In an electroluminescence spectrum (EL) of a luminescent film made of the manganese-chromium-doped zinc tungstate luminescent material, strong luminescent peaks exist in wavelength areas of 607 nm and 629 nm, and good excitation of green light and blue light can be obtained. The invention further provides a preparation method of the manganese-chromium-doped zinc tungstate luminescent material, a manganese-chromium-doped zinc tungstate luminescent film, a preparation method of the manganese-chromium-doped zinc tungstate luminescent film and a film electroluminescence device.

The present invention relates to a quadrivalent chromium doped gallium oxide crystal and a preparation method and application thereof, the molecular formula of the crystal is beta-(Ga1-x-yCrxAy) 2O3, 0.001<X<0.3, 0<Y<0.3, and A is a positive bivalent metal element. By doping of Cr in a beta-Ga2O3 crystal or double doping of the Cr and a bivalent metal cation in the beta-Ga2O3 crystal, the quadrivalent chromium doped beta-Ga2O3 crystal can be obtained, and the quadrivalent chromium doped gallium oxide crystal is a saturable absorption material with excellent properties. The crystal has stable physical and chemical properties and high thermal conductivity, and can also be used as a laser crystal.

A method is described to improve and produce purer Cr⁴⁺-doped laser materials and lasers with reduced co-incorporation of chromium in any other valence states, such as Cr³⁺, Cr²⁺, Cr⁵⁺, and Cr⁶⁺. The method includes: 1) certain crystals of olivine structure with large cation (Ca) in octahedral sites such as Cr⁴⁺:Ca₂GeO₄, Cr⁴⁺:Ca₂SiO₄, Cr⁴⁺:Ca₂Ge_xSi_1-xO₄ (where 0<x<1), and/or 2) high-temperature solution growth techniques that enable the growth of the crystals below the temperature of polymorphic transitions by using low melting point solvent based on oxide, fluoride and/or chloride compounds. Purer Cr⁴⁺-doped laser materials are characterized by a relatively high concentration of Cr⁴⁺-lasing ion in crystalline host that makes these materials suitable for compact high power (thin disk/wedge) NIR laser applications.

The invention provides a chromium-doped potassium scandium tungstate tunable laser crystal. 60-90at% of K2W2O7 serves as a fluxing agent, the cooling rate is 1-5DEG C/day, and the revolving speed is 5-30turns/minute. The Cr<3+>: KSc(WO4)3 crystal with high quality and bigger size grows. The crystal belongs to a trigonal system and has a space group structure. The crystal can serve as the tunable laser crystal of which the tunable range is 750-1200nm, and the solid crystal made of the crystal can be used for various fields, such as spectroscopy, biomedicine and military.

The invention belongs to the technical field of tungsten smelting and production and in particular relates to a method for preparing uniformly chromium-doped APT (ammonium paratungstate). The method for preparing the uniformly chromium doped APT comprises the following steps: (1) dissolving WO3 with ammonia; (2) adding soluble chromic salt, heating, and carrying out evaporation crystallization; (3) after liquid in a crystallizing pan is completely boiled, stopping steam introduction while stirring continuously; (4) when crystal nucleuses appear in the crystallizing pan, regulating a rotating speed, and maintaining a steam pressure; (5) when density of a solution reaches 1.1g/cm<3>, controlling a stirring speed, and maintaining the steam pressure; and (6) when the pH of the solution is 6.7-7.0, stopping heating, cooling and emptying. The method for preparing the uniformly chromium doped APT has the beneficial effects that APT powder with chromium uniformly distributed can be prepared, chromium is uniformly distributed at each APT crystal boundary, and molecular scale mixing is realized; and the prepared chromium doped APT can be used for effectively inhibiting abnormal growth of WC crystal grains in a liquid phase sintering process, so that properties of a hard alloy are greatly improved.

A cathode material for a lithium cell, in particular a lithium-sulfur cell. To improve the rate properties of the cell, the cathode material includes a chromium-doped lithium titanate, in particular of the general chemical formula: Li_4-xTi_5-2xCr_3xO_12-δ, where 0<x<0.6 applies, δ denotes oxygen vacancies, and 0≦δ applies. Also described is a corresponding chromium-doped lithium titanate, a method for the manufacture thereof, and a lithium cell and/or battery equipped therewith.

The invention discloses a chromium-doped inorganic nanocomposite material for 3D printing. The chromium-doped inorganic nanocomposite material comprises the following components in percentage by weight: 73-80% of ceramic precursor powder, 5-10% of nano-powder reinforcing material, 2-5% of chromium powder, 2-5% of a surfactant, 2-5% of an organic solvent, 1-4% of an inorganic binder and 5-10% of a low-temperature curing agent, wherein the particle size of the nano-powder reinforcing material is 20-200nm. By adopting the surfactant to perform deaggregation treatment on nano-powder, the nano-powder has excellent dispersivity; by adding the nano-powder into the ceramic precursor powder, the density and strength of ceramic can be improved, and the toughness of a product can be further upgraded; by mutually coordinating and matching the inorganic mixed powder, the inorganic binder and the low-temperature curing agent, the fast binding can be realized at low temperature; and the inorganic nanocomposite material can be used as a molding raw material of a 3D printing fast molding machine, the fast molding on the 3D printing machine can be effectively realized, and the chromium-doped inorganic nanocomposite material can be applied to a variety of types of 3D printing machines.

The invention relates to a preparation of a chromium-doped zinc selenide nanoparticle saturable absorber and an all-fiber Q-switched laser formed by the same, belonging to the technical field of fiberlaser. The chromium-doped zinc selenide has a wide absorption band and a large absorption cross section in a 1.5-2.1 [mu]m wave band, has a high damage threshold and can be used as an excellent saturable absorber. The chromium-doped zinc selenide nano-particles prepared by a femtosecond laser ablation method are doped into polyvinyl alcohol or polymethyl methacrylate to prepare the film saturableabsorber. The invention also provides an annular cavity Q-switched laser adopting the saturable absorber. The annular cavity Q-switched laser comprises a wavelength division multiplexer, a gain optical fiber, an optical isolator, a polarization controller, a saturable absorber and an optical fiber coupler. The saturable absorber based on the nano particle film has the advantages of simple preparation process, low cost, easiness in integration and the like, and meanwhile, the constructed all-fiber structure laser has the advantages of compact structure, stable performance and the like, and issuitable for practical application.

The invention discloses a treatment process for degrading dye waste water by ozone catalysis. The treatment process is characterized in that an adopted catalyst is a chromium-doped cerium oxide nanorod magnetic catalyst; due to special nanorod structure and doped metal-chromium element of the active components, the catalyst has high-efficiency ozone-catalytic degradation activity. The treatment process disclosed by the invention has the advantages of simple operation, low cost and high degradation efficiency and the like.

The invention belongs to the technical field of near infrared nano fluorescent materials and discloses a tetravalent chromium doped near infrared light-emitting temperature detecting nano material anda preparation and an application thereof. According to the near infrared light-emitting temperature detecting nano material, a base material is Ca2Al2SiO7 doped with tetravalent chromium, wherein thedoping amount is 0.1-2mole% the base material. The preparation method comprises the following steps: (1) mixing calcium nitrite, aluminum nitrate, chromic nitrate and silicic acid in water accordingto a stoichiometric ratio and the doping amount to obtain a mixture solution; and (2) under a stirring condition, dropwise adding hydrogen peroxide into the mixture solution at 80-100 DEG C, drying and grinding the mixture, and calcining the mixture in an aerobic environment to obtain the near infrared light-emitting temperature detecting nano material. The exciting and emitting bands of the nanomaterial are located in a biological transmitting window, can increase the signal-to-noise ratio and the resolution and deepen the depth of penetration, and have relatively high thermal sensitivity. The nano material is used in the field of near infrared light-emitting temperature detection.

The invention provides a chromium-doped magnetite hetero-phase Fenton catalyst and a preparation method of same. The catalyst is Fe<2.5>Cr<0.5>O4 and is prepared through a co-precipitation method. The method includes the following steps: 1) according to the molar ratio of Fe<2+>:Cr<3+> = 2.5:0.5, dissolving ferrous salt and chromium nitrate nonahydrate to obtain a metal ion mixed solution; 2) diluting an alkali solution twice, of which the volume is 1/4 of the metal ion mixed solution, and rapidly pouring the metal ion mixed solution into the alkali solution and performing a stirring reaction; and 3) after the stirring reaction is completed, repeatedly centrifuging the reaction product, washing, drying and grinding the product, and calcining the product at 400 DEG C for 3 h. The chromium-doped magnetite Fe<2.5>Cr<0.5>O4 has a cubic system spinel structure. The Fe<2.5>Cr<0.5>O4 has good degradation effect and high removal effect on anionic dye wastewater under neutral condition. In addition, the Fe<2.5>Cr<0.5>O4, under external magnetic field, can be rapidly separated, thereby achieving reuse of the catalyst.

The invention discloses a silver phosphate composite photocatalyst for treating rose bengal B in high-salt wastewater and a preparation method and application of the photocatalyst. The silver phosphate composite photocatalyst is prepared from a silver phosphate/polyaniline composite material, the silver phosphate/polyaniline composite material is loaded with chromium-doped strontium titanate, andpolyaniline silver phosphate is a carrier of the silver phosphate/polyaniline composite material and is loaded with silver phosphate. The preparation method of the photocatalyst comprises the step that a silver phosphate/polyaniline composite material solution is prepared and compounded with a chromium-doped strontium titanate solution to prepare the photocatalyst. The silver phosphate composite photocatalyst has the advantages of low cost, good photocatalytic performance, good stability, environmental protection and the like; the preparation method of the photocatalyst has the advantages thatthe process is simple, the raw materials are easy to obtain, the operation is easy, the preparation conditions are controllable, and the preparation method is environmentally friendly and free of pollution; the photocatalyst can effectively degrade and remove pollutants in the wastewater, especially has a good removal effect on the rose bengal B in the high-salt wastewater, and has high use valueand good application prospects.

The invention discloses a growth device of horizontal blended chromium semi-insulating gallium arsenide crystal, which is characterized by the following: comprising a horizontal placed tubular thermal field device; arranging a arsenic pressing chamber on lower of seed crystal chamber of reacting boat in reacting room corresponding to viewfinder of insulating layer. This invention possesses the advantages of simplified device, easy production, low coat, good stability and high crystal-forming ratio.

The invention relates to a preparation method of an inorganic nanometer material, in particular to a preparation method of a material with a cadmium sulfide/chromium-doped structure. The preparation method comprises the following steps of: after CdS powder is uniformly mixed with Cr powder by adopting a physical vapor deposition method, placing into a quartz boat, then placing a gold-plated Si chip below the quartz boat along the airflow direction and heating the position of the quartz boat to 890-910 DEG C after vacuum pumping; and finally obtaining a product after cooling. The preparation method has the advantages of strong process controllability, easiness for operation, low cost and high purity of the obtained product. The product prepared by the preparation method can be widely applied to the semiconductor industry.

A laser medium includes a single crystal of chromium-doped LiSc_l-xIn_xGe_1-ySi_yO₄, where 0≦x≦1 and 0≦y≦1. Preferably, x and y are not both 0. A laser, such as a tunable near infrared laser, can contain the laser medium.

The invention discloses a steady persistence nano material activated by low-dosage X rays and application thereof. The steady persistence nano material is prepared by adopting the steps that firstly,new tungsten and chromium doped steady persistence nano particles ZnGa2O4: W, Cr are synthesized, amination treatment is conducted on the surfaces of the steady persistence nano particles, the surfaces of the steady persistence nano particles are modified with a photosensitizer, and the steady persistence nano material is prepared. The steady persistence nano material has a steady persistence luminescence characteristic and the high luminescent intensity, and can be activated by the low-dosage X rays, the steady persistence nano material can solve the problem that a traditional photosensitizercannot conduct deep tissue photodynamics therapy due to the penetrating power is not strong enough, photodynamics therapy to the deep tissues is achieved, and meanwhile, the photodynamics therapy effect can be improved.