35results about How to "Good thickness controllability" patented technology

The invention provides a carbon fiber felt reinforcement inorganic polymer matrix composite and a preparation method of the carbon fiber felt reinforcement inorganic polymer matrix composite, and relates to an inorganic polymer matrix composite and a preparation method of the inorganic polymer matrix composite, in particular to the carbon fiber felt reinforcement inorganic polymer matrix composite and a preparation method of the carbon fiber felt reinforcement inorganic polymer matrix composite. The problems that an existing inorganic polymer material is poor in mechanical performance and low in toughness and the operation for adding short carbon fiber is complex are solved. The product is prepared through inorganic polymer material pulp and carbon fiber felt. The inorganic polymer material pulp is prepared through potassium hydroxide, silica sol and aluminosilicate powder. The method includes the steps of firstly, preparing the inorganic polymer material pulp; secondly, washing the carbon fiber felt; thirdly, preparing a prefabricated material blank; fourthly, preparing the carbon fiber felt reinforcement inorganic polymer matrix composite. The method is simple in process, low in cost, environmentally friendly and capable of being use for large-area preparation, and the prepared composite is good in mechanical property and wider in application range.

A resonant pressure sensor including one or more resonant-type strain gauges arranged on a diaphragm may include a sensor substrate made of silicon and including one surface on which one or more resonant-type strain gauge elements are arranged and the other surface which is polished to have a thickness corresponding to the diaphragm, a base substrate made of silicon and including one surface directly bonded with the other surface of the sensor substrate, a concave portion formed in a portion of the base substrate bonding with the sensor substrate, substantially forming the diaphragm in the sensor substrate, and including a predetermined gap that does not restrict a movable range of the diaphragm due to foreign substances and suppresses vibration of the diaphragm excited by vibration of the resonant-type strain gauge elements, one or more conducting holes, and a fluid.

The invention relates to a high-Fe-content doped BaTiO3 multiferroic thin-film material and a preparation method thereof. The molecular formula of the high-Fe-content doped BaTiO3 multiferroic thin-film material is BaTi<1-x>FexO3, wherein x is the atomic ratio of doped components and ranges from 0.01 to 0.4. The preparation method sequentially includes the steps that (1) a precursor is prepared; (2) a substrate is cleaned and pretreated; (3) a highly doped BaTiO3:Fe multiferroic thin film is prepared, specifically, the substrate obtained in the step (2) is spin-coated with the highly doped BaTiO3:Fe sol precursor prepared in the step (1), and then stepped annealing is conducted on the precursor; and (4) the sol coating and annealing processes of the step (3) are repeated, and a thin film sample of a needed thickness is obtained. A precursor solution is clear and transparent and can be stored for a long time; the grown thin film is uniform and compact in surface, good in crystallization property and free of impurity phases, and the grown thin film is good in thickness controllability and high in unipolarity; and the thin-film material has good ferroelectricity and ferromagnetism at the room temperature.

A F-P pressure sensor with a composite dielectric film disclosed by the present invention comprises an upper ferrule with a F-P resonant cavity, a lower ferrule which is axially fixedly connected with the upper ferrule and inserted into the lower ferrule. A ferrule for the fiber, and a pressure diaphragm covering the port of the F‑P resonator. At least one layer of composite dielectric film is grown on the back side of the pressure diaphragm and the silicon wafer at the bottom of the groove of the F-P resonator, and the composite dielectric film is SiO 2 / Ta 2 o 5 Thin film, Si 3 N 4 / Ta 2 o 5 thin film or SiO 2 / Ta 2 o 5 / Si 3 N 4 A multilayer film in at least one combination form. The invention has the advantages of simple structure, convenient and quick manufacture, low cost and high thermal stability. In the present invention, a composite dielectric film is grown on the back of the pressure diaphragm and the bottom surface of the upper ferrule groove, and the F-P resonant cavity is formed by connecting the pressure diaphragm with the upper ferrule to match the reflectivity of the system. This combined composite dielectric film is not only thermally stable At the same time, it can be combined according to the design requirements to obtain the reflectivity that meets the system requirements.

The invention relates to a preparation method of a GaN epitaxial structure taking a hexagonal BN-graphene composite layer as a buffer layer, and belongs to the technical field of photoelectron. The method comprises the steps of polishing and cleaning a copper substrate; growing an h-BN-graphene composite layer on the copper substrate; growing an AlN layer on the h-BN-graphene composite layer by anatomic layer deposition method; and growing a GaN layer on the AIN thin layer by a metal organic matter chemical vapor deposition method. The h-BN-graphene composite layer is used as the buffer layerbetween the copper substrate and the GaN epitaxial layer, thus, the problems of defect dislocation, crack and the like caused by lattice mismatching and thermal mismatching between the substrate andthe epitaxial layer can be solved, the stress between the substrate and an epitaxial material is effectively reduced, and the quality of the GaN epitaxial layer is improved.

The invention provides a bulk effect solar cell material which comprise a metal electrode, BiFeO3 ferroelectrics and a LaNiO3 / Si substrate, wherein the BiFeO3 ferroelectrics grows vertical to the direction of the LaNiO3 / Si substrate. The invention also provides a preparation method of the bulk effect solar cell material. The method comprises the following steps of: with BiFeO3 as structural material, preparing pure phase BiFeO3 film by using a sol-gel method, spin-coating the obtained BiFeO3 film on the LaNiO3 / Si substrate and carrying out stepped annealing at a high temperature, and finally sputtering electrodes to the BiFeO3 film. The BiFeO3 film disclosed by the invention has uniform and dense surface, good crystalline properties and no impurity phase, and can test photovoltaic effect by using a metal electrode-ferroelectric-buffer layer substrate sandwich structure. The test structure is simple and clear and larger open-circuit voltage can be obtained.

The invention relates to a production method of nitride epitaxial wafers and a gallium nitride laser device. The method comprises the following steps that 1, a copper substrate is polished and cleaned; 2, a graphene layer grows on the copper substrate; 3, the graphene layer growing on the copper substrate is transferred to target substrates; 4, an aluminum nitride thin layer grows on the graphene layer through an atomic layer deposition method; and 5, a GaN layer grows on the aluminum nitride thin layer through a metal organic matter chemical vapor deposition method. By means of the method, the nitride epitaxial wafers can grow on the different target substrates, the epitaxial wafers are transferred through the copper substrate, and therefore graphene is transferred to the different target substrates. The graphene layer is used as a buffer layer between the substrate and the GaN epitaxial layer, and the aluminum nitride layer is prepared through the atomic layer deposition method. Layer-by-layer growth of material atomic layers, good thickness controllability and high-precision film growth quality can be achieved, the large lattice mismatch problem between the substrate and the epitaxial layer is solved, the epitaxial layer quality is improved, and high-quality gallium nitride laser device can be obtained.

The invention relates to a preparation method of a gallium nitride epitaxial structure based on a molybdenum disulfide-graphene composite buffer layer, and belongs to the technical field of photoelectronics. The preparation method comprises the steps of performing cleaning on a silicon substrate; enabling a molybdenum disulfide-graphene composite layer to be grown on the silicon substrate; enabling an aluminum nitride layer to be grown on the molybdenum disulfide-graphene composite layer by adopting an atomic layer deposition method; and enabling a gallium nitride layer to be grown on the aluminum nitride layer by adopting a metal organic chemical vapor deposition method, and the like. By adopting the molybdenum disulfide-graphene composite layer as the buffer layer between the silicon substrate and the GaN epitaxial layer, the problems of defect malposition, cracks and the like caused by high lattice mismatch and thermal mismatch between the substrate and the epitaxial layer can be solved, the stress between the substrate and the epitaxial material can be lowered effectively, and the GaN epitaxial layer quality is improved.

The invention discloses a high-sensitivity surface plasma resonance sensor, which consists of a multi-layer medium layer, a transparent dielectric medium substrate (2) and a metal film layer (5), wherein the multi-layer medium layer is alternatively formed by a low-refractive-index medium thin layer (3) and a high-refractive-index medium thin layer (4), one side of the transparent dielectric medium substrate of the sensor is adjacent to a coupling prism (1), one side of the metal film layer is adjacent to a sample (6) to be tested, the total quantity of the low-refractive-index medium thin layer and the high-refractive-index medium thin layer in the multi-layer medium layer is of an odd number, the thickness of each layer is different from each other, and the low-refractive-index medium thin layer in the multi-layer medium layer is always adjacent to both the transparent dielectric medium substrate and the metal film layer. Compared with the traditional surface plasma resonance sensorbased on the single metal film layer, the sensitivity of the sensor is remarkably improved, at the same time the structure of the multi-layer medium layer is relatively simple, total thickness is smaller, the processing is easy, the cost is reduced, and stronger practical value can be realized.

The invention relates to a diamond-like coating used on the surface of a piston ring. The diamond-like coating consists of a primer layer, a gradient layer and an amplitude modulation layer from bottom to top. The amplitude modulation layer is a diamond-like coating doped with doping elements. The doping element is one or more of Cr, Si and Ti, and the content of the doping element in the amplitude modulation layer changes periodically in the form of sinusoidal fluctuations with the thickness of the amplitude modulation layer. Compared with the traditional single-layer structure or gradient layer structure, because the content of doping elements in the amplitude modulation layer of the diamond-like coating changes periodically with the thickness of the amplitude modulation layer in the form of sinusoidal fluctuations, the amplitude modulation of the diamond-like coating The layer has a multi-layer cyclic modulation structure; on the basis of high wear resistance and low friction coefficient, it is beneficial to reduce the internal stress of the coating, improve the toughness of the coating, and ensure the increase of the thickness of the diamond-like coating, while improving the piston of the diamond-like coating. ring durability.