9 results about "Perfect crystal" patented technology

The invention relates to a method for preparing polypropylene fibers by high-power stretching oriented crystallization, which comprises the following steps of: pretreating raw materials, melting, plasticizing and accurately metering, spinning and forming, and treating by using a three-section temperature control channel: enabling nascent fiber trickles to enter a temperature-controllable channel of a high-temperature slow cooling area, a medium-temperature oriented crystallization area and a low-temperature shaping area which are sequentially arranged from top to bottom; the areas are independently controlled in temperature and have a synergistic effect. According to the method disclosed by the invention, through coordinated regulation and control of three-section type temperature gradient and high-power stretching, a molecular chain is fully unwound and stretched in a high-temperature region firstly, and then is subjected to high-power stretching induction in an optimal crystallization temperature region to form a perfect crystal structure with high orientation, high crystallinity and narrow grain size distribution, so that high-strengthening structures such as shishkebab shish-kebab crystals and extended-chain crystals can be stably obtained; and the tensile strength and the initial modulus of the prepared polypropylene fiber are remarkably improved, the dry heat shrinkage rate is greatly reduced, the mechanical property and the dimensional stability are far superior to those of traditional process products, and the strict requirements of high-end industrial textiles are met.

The application discloses a kind of preparation method for preparing sheet low-sodium alpha-alumina using secondary aluminum ash.The method uses high-temperature sintering method to prepare alumina, and the performance of the product is improved by pickling or water washing.The obtained sheet low-sodium alpha-alumina has the advantages of perfect crystal form development, high purity, low sodium content, high alpha-alumina content, and micro-nano level particle size.The application does not add any morphology inducer, and eliminates the pollution problem caused by ammonia gas generated due to incomplete denitrification of aluminum ash, realizes the removal of harmful elements in aluminum ash, and achieves the purposes of harmless treatment and resource utilization.Also, the application overcomes the shortcomings of high cost, low efficiency, low purity and serious pollution in the prior art for preparing sheet alumina.The prepared sheet low-sodium alpha-alumina has great application potential in high-end automobile polishing, gem processing, high-precision microelectronic processing, cosmetics, functional coating and ceramic toughening, etc.

The invention provides an aluminum foil surface oxide dielectric constant calculation method and system, and the method comprises the steps: simulating the surface reaction of aluminum and water through reaction molecular dynamics, calculating the radial distribution function of the surface of a model after the reaction reaches equilibrium, and carrying out the systematic comparison of the radial distribution function with a known oxide structure model in a standard crystallography database. A known crystal model highly matched with the structural characteristics of a simulated product is screened out, complete crystallographic parameters of the model are extracted, and the dielectric constant of a corresponding substance is solved by using a first principle. According to the method, cross-scale connection from a surface reaction process to dielectric property calculation is realized, and the accuracy of dielectric constant calculation is improved; the problems of performance uncertainty and the like of oxidation films generated by the aluminum foil in different traditional formation processes are solved, and a new solution is provided for preparation of high-performance electronic information materials.

A gallium oxide crystal cutting method and clamp, adjust the bolt, set the rotating connecting rod 2 pointer at the specified scale; measure the size of the crystal, mark the position to be cut; adjust the position of the four fixed claws according to the size of the crystal; the (001) main surface of the crystal or the (100) main surface of the crystal is fixed on the horizontal plate of the four fixed claws, and the position to be cut of the crystal is arranged between the two adjusting frames; the clamp is fixed on the base of the cutting machine through the base support; the cutting parameters are set, the diamond wire with a diameter is selected, the feed speed is set, and the cutting is carried out; the gallium oxide crystal without cleavage is obtained; the crystal is not bonded, the size regular and size irregular crystal is clamped through the designed clamp, the crystal with different main surfaces is adjusted, the cutting angle suitable for cutting is adjusted, the complete crystal without cleavage is obtained, and the crystal with different main surfaces is cut.

The invention belongs to the technical field of semiconductor photosensitive elements, and particularly relates to a SiC-based semiconductor photosensitive element and a preparation method thereof. According to the method, by means of combination of high-temperature pyrolysis and pulse laser assistance, C-Si bonds on the surface of SiC are activated under high-temperature assistance, and the C-Si bonds are broken through laser irradiation; and meanwhile, doping elements adsorbed on the SiC surface are embedded into 3-5 atomic layers on the SiC surface in an atomic form to form a new lattice structure, so that a bulk phase complete crystal structure is ensured, lattice distortion is avoided, defects are inhibited, the high-quality SiC-based semiconductor photosensitive element is obtained, and the light response performance of the SiC-based semiconductor photosensitive element is improved. The problems that an existing SiC-based optical element has many bulk phase defects, doping elements are uncontrollable, and the surface is difficult to dope and modify are solved.

In order to form, on the surface of an LN single crystal, an LT single crystal, or the like, an epitaxial thin film that does not have rotating twin crystals and that exhibits characteristics comparable to those of an ideal perfect crystal, this epitaxial thin film obtained by adding, to lithium niobate or lithium tantalate serving as a base material, at least one alkali metal element of sodium, potassium, rubidium, cesium, or francium is epitaxially grown on the surface of a substrate by a high-frequency sputtering method.

This invention discloses a rapid and automatic sample rotation method for transmission electron microscopy (TEM) based on crystal orientation information obtained from electron backscatter diffraction (TKD-EBSD). The steps include: acquiring complete crystallographic information of each grain in the TEM sample; calculating the theoretical tilt angle parameters (α, β) required for the TEM sample stage; loading the TEM sample to be characterized into the TEM sample holder, and then transferring the sample holder into the TEM; making preliminary adjustments to the TEM parameters; controlling the tilt of the sample stage based on the theoretical tilt angle parameters (α, β); moving the target grain to the image center, and making secondary adjustments to the sample stage zone axis based on the alignment accuracy of the target zone axis; and completing the microstructure analysis of the target grain. This invention combines theoretical tilt angle analysis with the TEM sample stage tilting function, ultimately achieving precise and rapid tilting of the target zone axis of the grain of interest in the TEM, thus providing a reliable technical guarantee for efficient and accurate microscopic analysis.

The application belongs to the technical field of semiconductor photosensitive elements, and particularly relates to a SiC-based semiconductor photosensitive element and a preparation method thereof. The application combines high-temperature pyrolysis and pulse laser assistance, activates C-Si bonds on the surface of SiC under high-temperature assistance, and breaks the C-Si bonds through laser irradiation. Meanwhile, the doped elements adsorbed on the surface of SiC are embedded in the atomic layers of 3-5 layers on the surface of SiC in the form of atoms, forming a new lattice structure, so as to ensure the complete crystal structure of the bulk phase, avoid lattice distortion, inhibit the generation of defects, obtain a high-quality SiC-based semiconductor photosensitive element, and improve the light response performance of the semiconductor photosensitive element. The application solves the problems of many bulk phase defects, uncontrollable doped elements and difficult surface doping modification of the existing SiC-based optical element.

The invention discloses a preparation method of a raw material preposed Prussian white positive electrode material, and belongs to the technical field of sodium ion batteries. The preparation method comprises the following steps: firstly, introducing hydrogen cyanide gas into a sodium hydroxide solution to prepare a solution A; dissolving a soluble divalent transition metal salt, an organic acid sodium salt and a pH regulator in deionized water to prepare a solution B; mixing the solution A with the solution B in the step S2 or slowly dropwise adding the solution A and the solution B into the solution C at the same time, and carrying out a co-precipitation reaction at a certain temperature for a certain time to prepare a solid precipitate; the solution C is deionized water or a sodium salt solution; and finally centrifuging and washing the solid precipitate, and carrying out vacuum drying to prepare the Prussian white positive electrode material. According to the preparation method of the positive electrode material, the production cost is greatly reduced, and the prepared Prussian white positive electrode material has lower lattice water content, better and perfect crystal structure, higher specific capacity and excellent cycling stability.