61 results about "Nanocrystalline material" patented technology

The invention discloses a method for improving the thermal stability of a gradient nanocrystalline structure, and belongs to the technical field of metal material processing. According to the method, Mg-RE series alloy is used as a matrix, a matrix alloy ingot is heated for solution treatment, surface strengthening is carried out after water quenching and cooling, a gradient nanocrystalline layer is formed on the surface layer of an alloy sample, finally, the alloy sample is transferred into an aging oven for low-temperature aging, and cooling is carried out, so that the magnesium alloy is obtained. According to the method, the thermal stability of the magnesium alloy gradient nanocrystalline is improved through a synergistic strategy of component design and low-temperature aging, so that the grain growth rate of Mg-RE alloy gradient nanocrystalline structures treated by various different surface strengthening methods in a high-temperature environment can be remarkably reduced; the core bottleneck that a traditional magnesium alloy gradient nanocrystalline material is poor in thermal stability and single in applicable surface treatment method is solved; and the process does not need special equipment, can be seamlessly connected with various existing magnesium alloy surface strengthening production lines, and is low in process cost, simple and convenient to operate and easy to industrially popularize.

The high-pressure-resistant sensor comprises a shell, the shell comprises a body and a cover, a cavity is formed in the body, an opening is formed in one end in the length direction of the body, and the cover is detachably arranged at the opening to seal the shell; the sensing unit is contained in the cavity and comprises a double-coil vibration head module and a signal enhancement module, the double-coil vibration head module comprises a supporting framework, a magnetic tank and a coil assembly, the coil assembly is arranged on the supporting framework and comprises an inner coil and an outer coil which are coaxially arranged, and the diameter of the outer coil is larger than that of the inner coil; the axial directions of the inner coil and the outer coil are consistent with the length direction of the body; the signal enhancement module is coaxially arranged on the periphery of the double-coil vibration head module. According to the invention, the signal penetration capability is stronger, and a thicker metal shell can be penetrated; in addition, the magnetic tank and the coil assembly are wrapped by a strip-shaped amorphous nanocrystalline material with high magnetic permeability, so that the penetrating power of signals is effectively enhanced.

The invention belongs to the technical field of magnetic shielding materials, and particularly relates to a nanocrystalline slotting and soft magnetic alloy powder filling composite magnetic sheet and a preparation method thereof. The composite magnetic sheet comprises a magnetic material layer formed by alternately compounding a nanocrystalline material layer and a double-faced adhesive tape, the magnetic material layer is provided with regularly distributed slotting structures, and the slotting structures are filled with soft magnetic alloy powder. The preparation method comprises the following steps: alternately compounding a nanocrystalline material layer and a double-faced adhesive tape to form a magnetic material layer, and performing die cutting to form a regularly distributed slotting structure; or the nanocrystalline material composite layer is subjected to die cutting to form a regularly-distributed through slotting structure, and then the structure is compounded with the composite layer which is not slotted to obtain the magnetic material layer; and then filling and fixing the slotting structure by adopting soft magnetic alloy powder to obtain the composite magnetic sheet. According to the invention, the defect of easy magnetic saturation due to local lack of magnetic materials after slotting can be avoided, and the obtained composite magnetic sheet has low loss and high saturation current at the same time.

The invention is applicable to the technical field of photoelectricity, and provides a single-matrix white-light rare earth lead-free perovskite nanocrystal, a preparation method and application, and the single-matrix white-light rare earth lead-free perovskite nanocrystal is Eu < 3 + > ion doped Cs3TbCl6 nanocrystal. The rare earth ion Eu < 3 + > is doped into the Cs3TbCl6 nanocrystal, full-spectrum white light emission of blue light (matrix self-limiting state exciton emission), green light (Tb < 3 + > ion emission) and red light (Eu < 3 + > ion emission) is obtained, excellent thermal stability and environmental stability are achieved, and the nanocrystal material also shows excitation light dependent color adjustable emission (blue light, green light, red light and white light) and has good application prospects. The nanocrystal prepared based on a solution method can be applied to large-area flexible photoelectric devices; the fluorescent conversion layer can be used as a fluorescent conversion layer of a white light emitting diode with a high color rendering index, and can also be applied to anti-counterfeiting and information encryption.

The utility model relates to a miniature current transformer, which comprises a shell and a coil arranged in the shell, the coil comprises an iron core and a secondary winding wound on the surface of the nanocrystalline iron core, and the iron core is manufactured by performing heat treatment on nanocrystalline materials in a magnetic field; the shell is provided with a center channel which is arranged in a penetrating mode, a primary side wire can penetrate through the center channel, and the number of penetrating turns of the primary side wire is one. The miniature current transformer can realize output current at the secondary side when muA-level small current is input, fills the blank of a traditional transformer in the field of low-current measurement, improves the monitoring capability of a power system on a small current signal, is helpful for more accurately mastering the change condition of weak current in the power system, and improves the measurement accuracy. Accurate data support can be provided for electric leakage monitoring of some precise electronic equipment, current detection of a low-power-consumption circuit and the like, so that the safety and the reliability of a power system are improved.

The application belongs to the technical field of electromagnetic compatibility control design, and particularly relates to a marine low-ground-capacitance filter design method. The method specifically comprises the following steps: firstly, using an inductor as a main filter device, for a low-frequency band below 100 kHz, a magnetic core of the inductor uses an iron-based nanocrystalline material, for a low-frequency band from 100 kHz to 1 MHz, the magnetic core of the inductor uses MnZn magnetic material, and for a high-frequency band above 1 MHz, the magnetic core of the inductor uses NiZn magnetic material; secondly, based on the designed inductor, a multi-stage filter circuit combining low frequency and high frequency is designed; the filter circuit comprises: a plurality of common-mode inductors connected in series, a differential-mode capacitor Cx connected in parallel to both ends of the common-mode inductor, a common-mode capacitor Cy connected in parallel between a live wire and the ground, and a common-mode capacitor Cy connected in parallel between a zero wire and the ground; finally, modular packaging and glue filling are performed, so that the inductor of the filter circuit is parallel to the shell, the center position of the filter circuit is located at the center position of the shell, and overall insulation glue filling is not performed.

The application discloses a water-soluble quantum dot nanometer material and a preparation method and application thereof, and the nanometer material comprises quantum dots and carboxyl-terminated poly(lactic-co-glycolic acid) coated on surfaces of the quantum dots. The carboxyl-terminated poly(lactic-co-glycolic acid) is used for encapsulating CsPbBr3 perovskite quantum dots, and a water-soluble perovskite nanocrystal material is prepared, which can retain high quantum yield (PLQY=88%) and water-oxygen resistance (>=30 days) and almost completely retains optical performance of the perovskite quantum dots.

This invention discloses a high-boron Y–Ce–Co co-substituted nanocrystalline material and its preparation method. The general chemical formula of the nanocrystalline material, expressed as a percentage by mass, is: [RE x (Y y Ce 1‑y ) 1‑x ] z Fe 100‑z‑u‑v‑w Co u M v B w The composition is defined as follows: 0 ≤ x ≤ 0.9, 0.05 ≤ y ≤ 0.9, 25 ≤ z ≤ 35, 5 ≤ u ≤ 50, 0 ≤ v ≤ 3, 1.7 ≤ w ≤ 3. This invention utilizes Y–Ce–Co co-substitution to synergistically regulate the lattice occupancy, elemental valence states, and magnetic exchange interactions of the main phase, significantly improving the temperature stability of the Ce-rich system. Addressing the issues of abnormal grain growth and excessive Laves phase precipitation caused by Co introduction, increasing the mass percentage of B significantly enhances the alloy's amorphous forming ability, refines the main phase grains, and suppresses the formation of harmful second phases. Based on this compositional design, a low-linear-velocity melt rapid quenching process (12 to 18 m / s) can directly prepare materials with uniform nanocrystalline structures without subsequent crystallization annealing, achieving high coercivity and high temperature resistance while significantly reducing raw material costs.

The application provides a flexible perovskite battery and a preparation method and a photovoltaic module thereof, wherein an interface insertion layer is arranged between a flexible conductive substrate and a hole transport layer of the flexible perovskite battery, and the components of the interface insertion layer include metal oxide nanocrystal materials with a particle size range of 25nm-150nm. In the application, by introducing the interface insertion layer between the flexible conductive substrate and the hole transport layer of the flexible perovskite battery, the size effect and the surface chemical properties of the metal oxide nanocrystal are utilized to effectively improve the interface wettability, induce high-quality crystallization of perovskite, inhibit interface recombination through weak interaction, and enhance light absorption through light scattering, so that the film forming quality, the carrier transport efficiency and the light utilization of the flexible perovskite battery are synergistically improved; therefore, the flexible perovskite battery exhibits excellent photoelectric performance.

The application discloses an up-conversion circular polarization fluorescent device of perovskite quantum dots, which comprises, from bottom to top, a light-transmitting glass substrate, a parallel orientation layer, a reflection layer, a transparent separation layer and a composite nanomaterial layer; the reflection layer is a polymer cholesteric liquid crystal layer; the transparent separation layer is made of one of polymethyl methacrylate and polyvinyl alcohol; the composite nanocrystal material layer is composed of perovskite quantum dots / up-conversion nanocrystal composite nanomaterial; the perovskite quantum dots / up-conversion nanocrystal composite nanomaterial is prepared by an in-situ synthesis method. The device has the properties of circular polarization luminescence and up-conversion circular polarization luminescence, and has excellent performances such as high stability, high energy transfer efficiency, high radiation intensity and good repeatability.

The invention discloses a laminated insulation shielding material based on crushed magnetic nanocrystals and a preparation method thereof. The material structurally consists of a nanocrystal unit layer and an insulation coating layer, the nanocrystalline unit layer is formed by laminating 2-4 layers of nanocrystalline strips through an adhesive and carrying out magnetic crushing treatment to form a composite strip containing regular parallelogram fragments, and an eddy current path can be effectively cut off; and the insulating coating layer adopts a polyimide adhesive tape, and after the slit nanocrystal narrow strips are attached to the center, the reserved parts on the two sides are bent upwards to form a'three-surface 'coating structure for the upper surface, the lower surface and the two side edges of the nanocrystal, so that comprehensive and reliable insulation is realized. The preparation method comprises the steps of laminating and compounding, magnetic crushing treatment, two-time slitting, transferring and attaching, and edge covering and forming. The composite material has the advantages of high frequency, low magnetic loss and high insulation reliability, is particularly suitable for electromagnetic interference shielding of electronic equipment with the frequency band from hundred kHz to MHz, and solves the technical problems that a traditional nanocrystalline material is large in high-frequency eddy current loss and prone to short circuit.

The present application relates to a kind of pyridyl perovskite nanocrystal materials and its preparation and application, using PyMA as surface ligand, through the amino group on PyMA and the defect site on perovskite inorganic lattice Effective coordination bond is prepared to obtain new perovskite nanocrystal material.Compared with prior art, the nanocrystal material of the present application shows significantly enhanced nonlinear optical absorption performance in ultrafast femtosecond laser, different waveband region, which is due to the introduction of PyMA surface ligand, passivates the defect site in perovskite nanocrystal, improves the stability of perovskite nanocrystal structure.In addition, the aromatic structure of PyMA, promotes the regular arrangement of ligand on the surface of perovskite nanocrystal, improves the conductivity, enhances the electronic coupling between nanocrystal.Two kinds of factors synergistically endow the target material with excellent nonlinear absorption performance.

The invention relates to the technical field of magnetic materials, in particular to a preparation method of a low-loss low-resistance high-BS nanocrystalline shielding sheet, comprising a rubber material, a strip, a pressing roller, a buffer roller A, a magnetic crushing roller A, a magnetic crushing roller B, a magnetic crushing roller C, a magnetic crushing roller D, a buffer roller B and a receiving roll, and the preparation method comprises the following steps: S1, winding a high-Bs nanocrystalline strip into a magnetic ring; s2, horizontally placing the high-nanocrystalline magnetic ring wound in the step S1, and directly placing the high-nanocrystalline magnetic ring into a furnace body; s3, the interior of the furnace body is vacuumized till the negative pressure is 0.1 Mpa; and S4, nitrogen is injected into the furnace body until the positive pressure is 0.1 Mpa. Through an optimized heating scheme and an XY roller magnetic crushing scheme, the nanocrystalline material serving as the wireless charging shielding sheet has excellent soft magnetic performance, high magnetic conductance, low magnetic loss, high efficiency and low loss under the 100KHZ test condition, the magnetic conductivity of the electromagnetic shielding sheet after magnetic crushing is controlled within a certain range, and the consistency and stability of the shielding effect are good.

The utility model discloses an amorphous common mode inductor which comprises an annular magnetic core, a primary coil and a secondary coil, the primary coil is wound on the left side of the annular magnetic core, the secondary coil is wound on the right side of the annular magnetic core, the annular magnetic core is made of iron-based amorphous alloy, and the primary coil or the secondary coil is made of ferrite nanocrystalline. The stray magnetic field of the magnetic core is reduced by the annular magnetic core, so that magnetic lines are more concentrated, and the magnetic density is increased; the annular magnetic core has no air gap, the magnetic conduction rate of the amorphous common mode inductor is improved, the turn-to-turn capacitance of the coil is reduced, the frequency band is broadened, the ferrite nanocrystalline material adopted by the primary coil or the secondary coil has extremely high magnetic conductivity and working frequency, the magnetic conductivity is also very small along with the change of magnetic flux density and temperature, and the working efficiency is greatly improved. According to the amorphous common-mode inductor, large inductance can be obtained with a small number of turns of the coil, the size and weight of the inductor are reduced, common-mode interference can be restrained within a wide frequency range, and the anti-electromagnetic interference performance of the amorphous common-mode inductor is enhanced.

The invention discloses a large-capacity medium-voltage high-frequency transformer based on a closed nanocrystalline magnetic ring, belongs to the technical field of high-frequency transformer design, and comprises a nanocrystalline magnetic ring, a coil winding process and an insulation treatment process. The nanocrystalline magnetic ring comprises an annular stainless steel protective shell, a nanocrystalline strip and epoxy resin; according to the coil winding and insulating treatment process, a first prefabricated part composed of a primary coil, a water-cooling radiator, an insulating layer and a shielding layer, a second prefabricated part formed after main insulating epoxy resin is encapsulated, a secondary coil, a secondary coil insulating layer, a shielding layer, a third prefabricated part composed of a silicone rubber cable and external insulating epoxy resin are included. According to the invention, the nanocrystalline strip is encapsulated in the annular stainless steel protective shell, so that the performance of the nanocrystalline material is ensured not to be degraded, and on the basis, a semi-conductive shielding insulation design scheme and a process treatment flow based on the closed nanocrystalline magnetic ring are developed; and the design of high conversion efficiency, high power density and high reliability of the high-capacity medium-voltage high-frequency transformer is realized.

The invention discloses a magnetic core under a new process, and belongs to the technical field of magnetic core manufacturing. The magnetic core is made of amorphous and nanocrystalline materials, and excellent magnetic conductivity, electromagnetic energy conversion and transmission performance, frequency characteristic and temperature stability are achieved through an improved production process. By means of the process, the problems of magnetic core inner diameter size control, length manufacturing, fragility after annealing, rust prevention and the like are solved, the magnetic core can stably work for a long time within the range of minus 55 DEG C to 130 DEG C, and the magnetic core has the advantages of being low in coercivity and power consumption and is suitable for various high-frequency electronic equipment scenes.

The invention relates to the field of materials, and discloses a surface wave-shaped gold nanocrystalline material and a preparation method and application thereof.The preparation method comprises the steps that a chloroauric acid solution A1, a sodium hydroxide solution B1 and a solution C1 containing a first ligand react to obtain a first solution; the first ligand is selected from more than one of nitrite, citrate, sulfite and hypophosphite; a solution 1 containing a second ligand, a solution 2 containing a nanocrystalline template and a reducing agent solution 3 are mixed to obtain a mixed solution 4, the solution I is added into the mixed solution 4 to obtain a solution II, and the second ligand is selected from one or more of polyvinylpyrrolidone and poly (diallyldimethylammonium chloride) heat exchange sodium dodecyl benzene sulfonate; and mediating a mediating agent into the solution II to obtain the gold nanocrystalline material with the wavy surface. According to the method, the gold nanocrystals are synthesized in a water phase at normal temperature and normal pressure by adopting a wet chemical method, the surfaces of the prepared gold nanocrystals are wavy, and the roughness is continuously adjustable.

The application discloses a current transformer measurement method, and particularly relates to the field of current transformer monitoring and measurement, which comprises the following steps: before the measurement of the current transformer starts, the nanocrystalline material made core of the current transformer is initially magnetized, and the core is brought to a saturation state through a magnetic field; a known alternating current signal is applied to the current transformer through a primary winding, the alternating current generates an alternating magnetic field in the core, and the magnetic flux in the core changes; after the current transformer senses the change of the current, an induced electromotive force is generated through a secondary winding, and a measurement value is represented; the induced current in the secondary winding and the induced current of the primary winding change in a fixed proportional relationship, and the induced current is transmitted to a measurement device for collection. Through real-time monitoring of the external mechanical stress density and the core magnetic permeability decline rate, the system can timely judge and respond to the high stress state, and ensure the working stability and measurement accuracy of the current transformer under the high stress condition.

Embodiments of the present disclosure generally relate to systems and methods used in the manufacture of semiconductor devices. More particularly, embodiments of the present disclosure relate to a substrate processing chamber and components thereof for limiting wafer backside damage and methods for the same. In one embodiment, an electrostatic chuck disposed within a processing volume, including a first layer having a first grain size, wherein the first layer is formed of an amorphous material or a nano-crystalline material; and a second layer having a second grain size, wherein the second grain size is greater than the first grain size, wherein the first layer is disposed on the second layer.

The invention discloses a winding core for a winding type capacitor, and the winding core comprises a flexible substrate which is used as a bottom electrode. The ceramic dielectric layer is located above the flexible substrate, the ceramic dielectric layer comprises an amorphous-nanocrystalline material, the crystallinity of the amorphous-nanocrystalline material is 15-50%, and the grain size of the amorphous-nanocrystalline material is 5-40 nm; the top electrode layer is located above the ceramic dielectric layer, and the isolation layer is located above a top electrode.

The application relates to a ZSM-5 nanocrystal material with hollow multi-stage pores and a preparation method and application thereof, the ZSM-5 nanocrystal material has a closed hollow structure, the average grain size of the ZSM-5 nanocrystal material is 0.2-3.0 mu m, the ratio of the bulk phase silicon aluminum molar ratio to the surface silicon aluminum molar ratio is 1.0-1.5, the total specific surface area is 340-420 m 2 / g, the mesopore specific surface area is 40-150 m 2 / g, and the N2 adsorption and desorption curve presents an H4 type hysteresis loop. The ZSM-5 nanocrystal material has a closed hollow multi-stage pore structure and relatively excellent catalytic performance.

A magnetic isolation sheet, a coil module, and an electronic device are provided. The magnetic isolation sheet is used in a coil module in a wireless charging device. The magnetic isolation sheet includes a first nanocrystalline layer. The first nanocrystalline layer includes a first region in a shape of a non-closed ring. A material of the first region is a nanocrystal on which magnetic crushing has not been performed. Because the first region is in the shape of a non-closed ring, i.e., the first region is provided with a notch penetrating the first region, through the notch, a change in magnetic flux when magnetic lines of force in a magnetic field pass through the nanocrystal can be avoided, and the heating of a nanocrystalline material during wireless charging is avoided.

The utility model discloses a compact new energy thermal management filter. The compact new energy thermal management filter comprises a plastic housing, a Y2 capacitor, a DC support capacitor, a common mode inductor and a flexible PCB. A mounting groove is formed in the plastic shell, and a direct current support capacitor, a Y2 capacitor and a common mode inductor are arranged in the mounting groove; a plurality of connecting copper sheets are arranged on the plastic shell, the direct-current supporting capacitor and the common-mode inductor are connected through the connecting copper sheets, a plurality of side edge parts are outwards arranged on the plastic shell along the mounting groove, and the flexible PCBs are arranged on the side edge parts. The filter provided by the utility model has the following advantages: 1, the electronic components are reasonably arranged in the mounting groove of the plastic shell, so that the size of the filter is further reduced; 2, the connection copper sheet is adopted to ensure that the internal resistance of the capacitor is lower, the contact is good, and the vibration resistance is good; and 3, the capacitor is made of a metallized high-temperature film with the temperature of more than 120 DEG C, and the inductor is designed by adopting a nanocrystalline material, so that the capacitor can stably work for a long time under high-temperature and low-temperature occasions.

The application belongs to the technical field of nanocrystal material preparation, and particularly relates to a preparation method of organic perovskite nanocrystal and the organic perovskite nanocrystal. The method comprises the steps of obtaining a precursor solution and performing high-temperature vacuum extraction on the precursor solution. The step of obtaining the precursor solution at least comprises: heating and complexing organic precursor salt and a ligand to form an organic salt complex; the structure of the ligand is R1-R-SO3H, wherein R is selected from C6-C18 arylene, R1 is selected from C n H 2n+1 , H, and n is an integer from 1 to 18. The method can completely remove impurities in the synthesis of the organic perovskite nanocrystal during the high-temperature vacuum extraction operation by pre-synthesizing the organic salt complex, which has a higher melting point and binding stability, while avoiding the escape of small organic molecules caused by high-temperature vacuum extraction. The synthesized nanocrystal has adjustable wavelength, uniform size, high quantum efficiency and high stability.

The invention provides a hollow PtAgS nanocrystalline material as well as a preparation method and application thereof, and belongs to the technical field of synthesis of nano materials. A simple two-step hydrothermal method is adopted, firstly, a gel precursor is synthesized to serve as a self-sacrifice template, then a platinum source, a silver source, a sulfur source and the template are subjected to a hydrothermal reaction together, and the hollow PtAgS nanocrystal is obtained. According to the preparation method disclosed by the invention, platinum and silver atoms are induced to diffuse outwards from a sulfur-containing core by utilizing twin crystal defects formed in the initial stage of reaction, so that a hollow structure is formed; the process is simple and efficient, the product is pure, the structure is uniform and controllable, and the prepared hollow PtAgS nanocrystal is a ternary alloy nanocrystal with a uniform hollow structure, has twin crystal defects, shows excellent soft magnetic properties including high saturation magnetization and low coercive force, is particularly suitable for high-frequency and low-loss magnetic devices, and has wide application prospects. Such as miniaturized electronic components and magnetic sensors, and has a wide industrial application prospect.

This invention discloses a five-phase motor with a nanocrystalline stator core, comprising a stator module and a rotor. The stator has a pentagonal structure, with each side composed of several stator tooth modules and permanent magnets. The stator tooth modules have a U-shaped structure and are made of nanocrystalline material, with slots for embedded windings. The rotor has several rotor teeth evenly distributed along its circumference, and the rotor teeth have a fan-shaped structure radially, inclined at a certain angle to the rotor axis to solve the problem of uneven air gap magnetic field. The pentagonal structure of the stator solves the problem of the difficulty in processing nanocrystalline material into conventional motor stator cores. Motors using nanocrystalline stator core material can effectively reduce core loss and improve motor efficiency during high-speed operation.

The invention belongs to the technical field of crystal catalytic material preparation and pollutant degradation, and relates to a CoSe nanocrystalline catalytic material as well as a preparation method and application thereof. The chemical formula of the CoSe nanocrystal is CoSe, the CoSe nanocrystal is formed by assembling Co atoms and Se atoms through covalent bonds, the crystal size is concentrated at 5-20 nm, and Co exists in a mixed valence of + 2 / + 3. The nanocrystal is synthesized in situ through controllable pyrolysis and gas-phase selenylation by combining coordination self-assembly with in-situ phase engineering. The CoSe nanocrystalline material is used as a peroxymonosulfate (PMS) activation catalyst for oxidative degradation of tetracycline.

There is provided, in one example aspect, a magnetic core structure comprising a plurality of core portions that are made of a nanocrystalline material with a reduced magnetic permeability and that are stacked to reduce eddy currents. There is provided, in another aspect, a method of manufacturing a nanocrystalline material comprising: reducing a magnetic permeability of a nanocrystalline material; and forming a plurality of separate flakes in the nanocrystalline material.

The invention discloses a hemicellulose nanocrystalline material with double-refraction performance and a preparation method thereof, and belongs to the technical field of optical materials.The preparation method of the hemicellulose nanocrystalline material with the double-refraction performance comprises the following steps that hemicellulose is extracted from plant straw, the hemicellulose is resuspended with pure water, and the hemicellulose nanocrystal material with the double-refraction performance is obtained; the preparation method comprises the following steps: performing ultrasonic treatment on hemicellulose, standing, arranging and aggregating hemicellulose molecules to form nanocrystal particles, and placing a hemicellulose nanocrystal particle suspension in the middle of double-layer thin glass to perform solvent restrictive evaporation induced self-assembly, thereby finally preparing the hemicellulose nanocrystal material (namely, the hemicellulose nanocrystal self-assembly material). The invention also provides a plant straw hemicellulose extraction method, a hemicellulose nano-particle preparation method and a nano-particle self-assembly technology, the prepared hemicellulose nano-crystal self-assembly material shows colored double refractivity, and a foundation is laid for subsequent preparation of a novel glycosyl material.

The invention provides nanocrystalline copper and a preparation method thereof, and relates to the technical field of nanocrystalline material preparation, and the preparation method comprises the following steps: preparing deposited nano-copper by adopting an electro-deposition method, and then performing high-pressure torsion treatment on the deposited nano-copper to obtain the nanocrystalline copper. Initially uniform block nanocrystalline copper is obtained through an electro-deposition method, then high-pressure torsion treatment is conducted on the initial nanocrystalline copper, the grain size of the nanocrystalline copper is further cut, a small-angle grain boundary is introduced, and high-stability uniform nanocrystalline block copper is obtained. Wherein the grain size of the initial nanocrystalline copper is small, the initial nanocrystalline copper is uniformly distributed and presents isometric crystals, the fine initial grain means that the grain boundary proportion is high and the dislocation storage capacity is low, the stable nanocrystalline copper can be obtained by refining the grain through relatively mild high-pressure torsion treatment, the grain boundary energy can be reduced, and the grain boundary energy can be uniformly sheared and deformed; on one hand, the nanostructure is densified, and on the other hand, after the grain boundary energy is reduced, the nanostructure is more stable at high temperature.