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

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 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 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 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 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 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.