52results about How to "The lattice constant decreases" patented technology

The disclosed IDT/h-BN/c-BN/ diamond multilayer membrane structure SAW device comprises: from bottom to top, a nano-diamond membrane base prepared on mirror silicon, a nano c-BN membrane intermediate layer, a high-C-axis preferred orientated nano h-BN membrane, and an IDT. This invention can be used on condition of 2. 5GHz, high electromechanical coupling factor, smaller loss at 8w propagation, and low frequency temperature coefficient.

The invention provides a GeSn quantum well infrared illuminator with a strain source. The structure is characterized in that a relaxation layer GeSn is arranged on a silicon substrate; strain source potential barriers n+ SiGe and p+ SiGe are arranged on the relaxation layer and grows at the peripheral region of an active region GeSn in pairs; and one end of the strain source potential barrier SiGe is a metal contact electrode. The lattice constant of the material of the strain source SiGe is smaller than that of the material of the active region GeSn, thereby forming single-axis compression strain along the z axis direction on the active region GeSn material, and forming a double-axis tensile strain along the xy plane; the strain state facilitates the GeSn material to change from an indirect band gap to a direct band gap; and through forming a heterojunction quantum well structure through the GeSn and the SiGe, fast and efficient radiative recombination of electron-hole is realized. The structure can limit electrons and holes in the well efficiently, thereby enlarging recombination rate of the electron and hole pairs, and improving luminous efficiency of an illuminator.

A laminated ceramic capacitor which has a dielectric ceramic with a high dielectric constant and has excellent reliability against changes in temperature and mechanical shocks, even when dielectric ceramic layers are reduced in thickness employs a dielectric ceramic containing (Ba_1-xCa_x)_yTiO₃ (where 0.045≦x≦0.15 and 0.98≦y≦1.05) as its main constituent and containing Re₂O₃ (where Re is at least one of Gd, Dy, Ho, Yb, and Y), MgO, MnO, V₂O₅, and SiO₂ as accessory constituents, which is represented by the general formula: 100(Ba_1-xCa_x)_yTiO₃+aRe₂O₃+bMgO+cMnO+dV₂O₅+eSiO₂, and satisfies each of the following conditions: 0.65≦a≦1.5; 0.98≦y≦1.05; 0.15≦b≦2.0; 0.4≦c≦1.5; 0.02≦d≦0.25; and 0.2≦e≦3.0.

The invention discloses a nitride LED epitaxy structure suitable for heavy current driving, and relates to the technical field of manufacturing of LED optoelectronic devices. According to the structure of the nitride LED epitaxy structure suitable for heavy current driving, a substrate sequentially comprises an n-type compound semiconductor, an active area and a p-type compound semiconductor from bottom to top, and is characterized in that the active area is formed by alternatively overlapping m quantum wells and m+1 quantum barriers, the m is any natural number, the maximum forbidden band gap of the quantum barriers is larger than the maximum forbidden band gap of the adjacent quantum wells, and the maximum forbidden band gap or film layer thickness of different quantum barriers is distributed in a gradual variation mode. Compared with the prior art, the nitride LED epitaxy structure suitable for heavy current driving can reduce or eliminate the problem of decrease of the energy efficiency of nitride LEDs under the condition of heavy current driving, and improve the quantum efficiency of devices.

The invention provides a high frequency surface acoustic wave device with an AlN (aluminum nitride) film as an interlayer. The device is characterized in that an a-axis preferred orientation AlN film is taken as a CVD (chemical vapor deposition) diamond substrate and a c-axis preferred orientation ZnO film is taken as an interlayer, the substrate and the interlayer are formed into an IDT(interdigital transducer)/ZnO/a-axis preferred orientation AlN/diamond multi-layered membrane structure and the structure is stacked with the IDT in sequence to form the high frequency surface acoustic wave device; the preparation method comprises the following steps of preparing an a-axis preferred oritention AlN film interlayer, and preparing a c-axis preferred oritentation ZnO film on the a-axis preferred orientation AlN film interlayer. The device and the preparation method provided by the invention have the following advantages that the sound velocity frequency dispersion caused by a large sound velocity gap between nanodiamond and ZnO can be solved, the application demand of the surface acoustic wave with high frequency above 4.8 GHz can be met, and moreover, the process is simple and easy to implement, and is beneficial for large-scale population and application.

The invention discloses an electrochemical method for preparing a fluorine-containing hydroxyapatite/zirconia transition coating on the surface of medical titanium. The method comprises the steps that: electro-deposition is carried in an electrolytic tank with a three-electrode system, wherein a medical titanium chip is adopted as a working electrode; a Zr(OH)4 plating is deposited in a zirconyl nitrate solution with a certain concentration and a certain pH value, wherein the deposition current is 11.1mA and the deposition time is 40s; a fluorine-containing hydroxyapatite (FHA) plating is deposited in an electrolyte which has a certain concentration and a certain pH value and which is composed of calcium nitrate, ammonium dihydrogen phosphate, and sodium fluoride, wherein the deposition current is 0.8mA and the deposition time is 3600s; and vacuum sintering is carried out under a temperature of 450 DEG C, such that the FHA/ZrO2 transition coating is obtained. According to the invention, fluorine partially substitutes hydroxyl group in apatite, fluorine ions are smaller than hydroxyl groups, and FHA lattice constant is small, such that FHA solubility is lower than HA. A coating morphology is changed from a micron-level chrysanthemum petal shape into a nano-level cone shape. With an antibacterial effect of F ions, dental caries can also be prevented. ZrO2 serves as a transition layer between the titanium substrate and the FHA coating, and the bonding strength between the FHA/ZrO2 transition coating and the Ti substrate is greatly improved. The bonding strength between the FHA/ZrO2 transition coating and the titanium substrate is high, a physiological solubility resistance is high, and antibacterial performance is good. The provided product has certain potential to be developed into an oral medical material with good development prospect.

The invention relates to an LED illuminating device and a preparation method thereof. The device is characterized by comprising an LED apparatus, an LED circuit board, a heat dissipator and a power supply controller. The LED apparatus is arranged on the LED circuit board, the LED circuit board is arranged above the heat dissipator, and the power supply controller is connected to the LED circuit board through a wire. The LED illuminating device can emit approximate natural light.

The invention provides a Ge channel metal-oxide-semiconductor field-effect transistor (MOSFET) with an InAlP cover layer. The MOSFET (10) is characterized in that a Ge channel (101) is positioned on a substrate (108), the InAlP cover layer (102) is arranged above the Ge channel, an insulating dielectric film (103) is positioned between the InAlP cover layer and a gate (106), an insulating gap wall (107) separates the gate and a source/drain area (104 and 105), and an insulating gap wall separates the InAlP cover layer and the source/drain area. InAlP has a larger forbidden bandwidth than Ge, and effective band offset is formed at the positions of a conduction band and an interface valence band of Ge and InAlP so as to limit a conducting charge carrier in a Ge channel layer.

The invention provides a GaN-based high-electron-mobility transistor epitaxial wafer and a preparation method thereof, and belongs to the technical field of semiconductors. The GaN-based high-electron-mobility transistor epitaxial wafer comprises a substrate, a buffer layer, a high-resistance buffer layer, a channel layer, an AlGaN barrier layer and a cap layer, wherein the buffer layer, the high-resistance buffer layer, the channel layer, the AlGaN barrier layer and the cap layer are stacked on the substrate; the cap layer comprises a first semiconductor layer and a second semiconductor layer which are stacked in sequence; the first semiconductor layer is of a P-type doped InxGa1-xN/MgN superlattice structure, wherein x is larger than 0 and is smaller than 1; the second semiconductor layer is of a P-type doped AlyGa1-yN/InzGa1zN superlattice structure, wherein y is larger than 0 and smaller than 1, and z is larger than 0 and smaller than 1. According to the epitaxial wafer, the doping concentration of Mg in the cap layer can be improved, an enhanced HEMT is formed, and meanwhile, the crystal quality of the enhanced HEMT epitaxial wafer is improved.

The invention provides nickel-based high-temperature alloy powder and a preparation method for applying the nickel-based high-temperature alloy powder to a hollow turbine blade, and solves the technical problem of cracking in the process of preparing the hollow turbine blade through selective laser melting. The Ni-Cr-Co-Ti-W alloy material comprises the following components in percentage by weight: 25% to 30% of Cr, 17.5% to 19% of Co, 2.5% to 3.0% of Al, 2.3% to 2.5% of Ta, 2.6% to 2.8% of Ti, 1.7% to 2.1% of W, 1.5% to 2.5% of Re, 0.1% to 0.15% of C, 0.8% to 1% of Cb, 0.2% to 0.3% of Zr, 0.005% to 0.01% of B, 0.5% to 0.7% of V and the balance of Ni. The method can be widely applied to the technical field of additive manufacturing.

The invention provides a blue light-ultraviolet continuously-adjustable aluminate fluorescent powder and a preparation method thereof. A Si-N bond is substituted for a Al-O bond; after the substitution, the internal structure of the fluorescent powder is improved; and thus, the luminescent spectrum of the fluorescent powder is continuously adjustable from blue light to ultraviolet light according to different substitution proportions. The fluorescent powder is more stable due to the doping of the Si-N key. The Si-N bond and Al-O bond have similar bond lengths, Si and Al, and O and N have similar bonding characteristics according to the diagonal line principle, so the Al-O bond in the aluminate-base fluorescent powder can be easily partially substituted by the Si-N bond; according to the charge compensation effect, after (SiN)+ is substituted for (AlO)+, the charge balance can be maintained; the bond length of the Si-N bond is slightly smaller than that of the Al-O bond, so that the matrix lattice constant is reduced, the cell volume is correspondingly reduced, and the atomic arrangement in the matrix is closer; and N with relatively smaller electronegativity can stabilize the Ce<2+>, so the material stability and light-emitting stability of the fluorescent powder are enhanced.

The invention relates to a soda recovery furnace brasque material based on aluminum-rich magnesium aluminate spinel and a preparation method thereof. The preparation method comprises the following steps of: firstly, mixing 50-80wt% of aluminum-rich magnesium aluminate spinel aggregate with 20-50wt% of aluminum-rich magnesium aluminate spinel fine powder to obtain a mixture, adding a binding agent accounting for 4-15wt% of the mixture, stirring, constructing, curing and roasting the mixture to prepare a soda recovery furnace brasque material based on aluminum-rich magnesium aluminate spinel. The main physical properties of the chrome-free and alkali-resistant refractory material based on aluminum-rich magnesium aluminate spinel prepared by the preparation method provided by the invention are as follows: the volume density is 2.60-2.85 g/cm3, the compression strength is 30-45 MPa, and the linear changing rate is 0.19-0.47%. The preparation method provided by the invention has the advantages of simple technique and low energy consumption, and the prepared soda recovery furnace brasque material based on aluminum-rich magnesium aluminate spinel is free of chromium and is excellent in alkali corrosion resistance.

The invention discloses a preparation method of rare earth polishing powder. The method comprises the following steps of: preparing rare earth fluorocarbonate of rare earth elements lanthanum, cerium,samarium and yttrium, with the addition amount of fluorine being 5%-10% of REO; and roasting and grading the rare earth fluorocarbonate to obtain the rare earth polishing powder. The invention further discloses rare earth polishing powder, which comprises cerium oxide and yttrium oxide, the total amount of rare earth oxide of cerium oxide accounts for 45w%-85w% of CeO2/TREO, the total amount of rare earth oxide of yttrium oxide accounts for 1w%-10w% of Y2O3/TREO, and the molar ratio of REO to Y2O3 is 1:0.015-0.15. By precisely calculating the addition amount of Y2O3, the lattice constant of CeO2 is reduced, oxygen vacancies are formed, and the wear resistance, grinding force and reaction activity of the polishing powder are enhanced.

The invention discloses a Ti-Nb-Mo-O series high-damp alloy. The alloy comprises the following chemical components in percentage by atom: 73.5% of Ti, 15.0%-23.0% of Nb, 2.0%-10.0% of Mo and 1.5% of O. In the high-damp alloy disclosed by the invention, two elements with stable beta phases namely Nb and Mo, and O atoms are added, thus the Ti-Nb-Mo-O series alloy belongs to a beta-phase titanium alloy. In the preparation method of the Ti-Nb-Mo-O series high-damp alloy, smelting is repeatedly carried out at least five times by adopting a vacuum arc process, and heat treatment is carried out after preparing an alloy ingot; the O atoms are solved in the beta phase in a solid mode; the stability of a beta-phase substrate (body-centered cubic structure) in the alloy is enhanced through adding Nb and Mo elements; and the alloy has high damp value, good mechanical property and the like. The high-damp alloy of the invention can be used at the temperature ranging from 200 DEG C-300 DEG C and has the characteristics of high damp value, wider effective damp temperature interval, good mechanical property and the like.

The planar photon crystal bundle-dispersing polarimeter refers to the field of electromagnetic wave bundle-dispersing polarimeter. Its character is that insert the dielectric stick to the background media whose refractive index is much lower than that of the dielectric stick to form a planar seasonal structure. Along the incident direction of the electromagnetic wave, it's orderly composed of three parts that are the left transmission-enhancing film, the main part and the right transmission-enhancing film. The radius of the dielectric stick in the main part is higher than that of the other two parts. The incident side of the main part is pressed close to the outdiffusing side of the left transmission-enhancing film, and the incident side of the right transmission-enhancing film is pressed close to the side of the outdiffusing side of the main part. This invention has an advantage that the fixity of all the standards of the photon crystal itself won't metamorphose. When the work wavelength is the same, the crystal lattice constant of this invention is much smaller than that of the present planar photon crystal bundle-dispersing polarimeter. Therefore it's portable and cabinet. This invention can also transmit two reciprocally vertical polarizing ponderance at the same time, so it's polarizing degree is high and the transmitted index is big.

The invention relates to a high-strength fusion smelter for colored strengthening smelting. The smelter comprises a smelter wall port, an upper smelter wall, a smelter wall above a liquid line, a liquid line smelter wall, a smelter wall below the liquid line, a secondary working layer, a liquid outlet nozzle and a smelter bottom. All the parts of the smelter are made of fire-resistance materials,by analyzing working conditions of different parts of the high-strength fusion smelter for colored strengthening smelting, different kinds of fire-resistance material brasque are used as the corresponding parts, one or more properties of the erosion resistance, thermal shock resistance, washing resistance and permeability resistance of the brasque at the part are improved, the service life of thebrasque is greatly improved, frequent repairing and brasque replacement are avoided, and a large number of human resources and financial resources are saved.

The invention belongs to the field of metal material magnesium alloys, and discloses a low-cost high-strength high-modulus cast magnesium alloy and a preparation method thereof. According to the total weight of the cast magnesium alloy, the cast magnesium alloy comprises 3.0%-10.0% of Zn, 2%-10.0% of Li, 1%-6.0% of Al, 0.01%-3.0% of Mn, 0.01%-1.0% of Cu and an impurity element Filt. 0.005%, the impurity element of which is Nilt; 0.002%, and the balance of Mg. According to the preparation method, Zn, Li, Al, Cu, Mn and other rare-earth-free elements are adopted, a novel design method of the double-configuration high-modulus-nanophase reinforced high-strength high-modulus magnesium alloy is utilized, the modulus of the alloy is improved through micron-scale primary high-modulus second phase precipitation separated out of the alloy, a nanoscale secondary precipitation strengthening phase is regulated and controlled through a subsequent heat treatment process, the strength and toughness of the alloy are guaranteed, and the high-strength high-modulus magnesium alloy is obtained. Therefore, cooperative control of low cost, high modulus and high strength and toughness is achieved.

The invention discloses a preparation method of an efficient electrode plate. The preparation method comprises the following steps: (1) preparing a base material; (2) carrying out surface treatment of the base material; (3) coating a substrate layer; (4) coating a middle layer; (5) coating a surface layer; and (6) sintering. A precursor solution A is used as the substrate layer to seal the bottom of the substrate, so that the binding force between the active components of the substrate layer and the substrate is effectively improved, the conductivity and passivation resistance of the substrate are enhanced, and the service life of the electrode is prolonged in the use process. A precursor solution B is adopted as the middle layer, so that on one hand, cracks of the coating are reduced, diffusion and permeation of oxygen generated in the use process to the substrate are further slowed down, and generation of a high-resistance layer is reduced or hindered; and on the other hand, the oxygen evolution potential of the electrode is improved. A precursor solution C is adopted as the surface layer, so that the poisoning effect of sewage on the active coating can be effectively avoided.