78 results about "Aggregation phenomenon" patented technology

The invention provides an IGBT device with an integrated voltage sampling function, and belongs to the technical field of power semiconductor devices. A channel in which a JFET structure is introducedin a body region is in a normally-closed state, the device is in a forward turning-on state, and carriers are stored in the body region, so that an electric conductance modulating action is strengthened, and the saturated turning-on voltage drop of the device is reduced; in a turning-off state of the device, the body region plays a floating field limiting ring role, so that an electric field aggregation phenomena at the bottom of a groove gate is weakened, and the voltage withstand reliability of the device is improved; the grid electrode and the source electrode of the introduced JFET structure are connected with a peripheral control circuit and a sampling port respectively, a voltage sampling function can be realized by using a mapping reaction between the voltage change of the source electrode of the JFET structure and withstanding voltage of an IGBT, and the forward blocking characteristic of the device cannot be damaged while an electric isolation effect is reached; and the adjustment for voltage sampling rate is realized by changing the grid electrode bias voltage of the JFET structure, so that the requirement of different application conditions on voltage sampling is met. The IGBT device is simple in sampling structure, and is compatible with an existing technology.

The invention discloses a method for performing laser braze welding on diamonds by using double beams. The method comprises the following steps: providing a matrix for performing braze welding on thediamonds and forming a V-shaped groove in the surface of the matrix; coating a brazing material layer for performing braze welding on the diamonds in the V-shaped groove; providing a wolfram wire mesh, arranging a plurality of grids for putting the diamonds in the wolfram wire mesh; putting the wolfram wire mesh above the brazing material; putting the diamonds into the grids of the wolfram wire mesh to ensure that the diamonds and the brazing material layer have certain contact height; symmetrically abreast arranging two laser heads in the welding direction; starting a laser welding system. Byutilizing the double laser beams, the brazing material layer is aslant input from the two sides of the diamonds, and laser braze welding is carried out. The invention also provides a system for performing laser braze welding on the diamonds by utilizing the double beams. According to the method and the system disclosed by the invention, burning loss oxidation and graphitization of the surfaces ofthe diamonds are reduced, the bonding strength between the brazing material layer and the diamonds is improved, the aggregation phenomenon of the diamonds is avoided, and a desired arrangement sequence of the diamonds can be obtained.

A capacitive humidity sensor includes: a humidity sensing element with a humidity sensitive film and electrodes; and a processing circuit. The film has a dielectric constant variable in accordance with moisture. The electrodes detect capacitance of the film and outputs a signal corresponding to the capacitance. The processing circuit processes the signal. The film is made of inorganic material having fine pores for adsorbing the moisture. A diameter of the fine pores is set to be a predetermined diameter so that capillary tube aggregation phenomenon occurs at a predetermined relative humidity. The capacitance of the film has a change rate with respect to the relative humidity. The change rate in case of the relative humidity higher than the predetermined relative humidity is larger than that in case of the relative humidity lower than the predetermined relative humidity.

The invention discloses a copper-doped ZnO-ZrO2 sosoloid catalyst and a preparing method and application thereof. The preparing method of the catalyst comprises the steps of preparing a metal and nitrate mixed solution through Cu(NO3)2.3H2O, Zn(NO3)2.6H2O and Zr(NO3)4.5H2O; at the reaction temperature of 50-90 DEG C, dropwise adding the metal and nitrate mixed solution and a Na2CO3 solution into areaction container, maintaining the reaction temperature, conducting stirring, and conducting ageing at the reaction temperature; conducting centrifuging to obtain a solid precipitate after a productis cooled; then utilizing deionized water for washing the solid precipitate; then drying the precipitate to obtain a catalyst precursor; putting the catalyst precursor into a tube furnace for calcination to obtain a catalyst parent. By means of the copper-doped ZnO-ZrO2 sosoloid catalyst and the preparing method and application thereof, the dispersity of active components in the catalyst is improved, the sintering and aggregation phenomena of the catalyst are effectively inhibited, and the carbon dioxide conversion rate and methyl alcohol selectivity are high.

The invention discloses a method for preparing modified graphene reinforced copper-based composite material. The method specifically comprises the following steps: uniformly mixing a copper nitrate solution with a graphene oxide solution, and then adding hydrazine hydrate for carrying out reduction reaction; then cleaning a mixed solution after reaction, and drying precipitate, thus obtaining modified graphene composite powder; then carrying out liquid-phase powder mixing on the modified graphene composite powder and copper powder, drying by evaporating, cold-pressing and sintering, thus obtaining the modified graphene reinforced copper-based composite material. According to the method disclosed by the invention, surface modification is carried out on graphene, and copper particles are inserted between graphene sheet layers, so that the graphene is not easy to generate an aggregation phenomenon when the graphene is mixed with matrix copper powder; during a sintering process, a sintering neck can be formed by the copper particles of the graphene sheet layers and matrix copper, so that strong graphene / copper interface bonding strength can be favorably obtained; the modified graphenereinforced copper-based composite material prepared by adopting the method disclosed by the invention is uniform in organization and higher in strength and electrical conductivity.

Provided is a semiconductor nanoparticle-encapsulating vinyl polymer including vinyl polymer particles; and semi-conductor nanoparticles, uniformly dispersed in the vinyl polymer particles, having an average particle size of 1 to 150 nm, wherein the semiconductor nanoparticles are encapsulated by the vinyl polymer particles. Provided is also a mixture of the semiconductor nanoparticle-encapsulating vinyl polymer with a commercially available vinyl polymer. In the nanoparticle-encapsulating vinyl polymer and the mixture, since the semiconductor nanoparticles are encapsulated by the vinyl polymer particles, they are highly dispersed even in vinyl polymer products. Therefore; an aggregation phenomenon of semi-conductor nanoparticles that may be caused by physical mixing of semiconductor nanoparticles and a commercially available vinyl polymer can be prevented, thereby remarkably increasing a reduction in dioxin emission during incineration of the wastes of vinyl polymer products. Furthermore, the semiconductor nanoparticles of the semiconductor nanoparticle-encapsulating vinyl polymer can remarkably increase photodegradation efficiency due to the photocatalytic activity of the nanoparticles. In addition, the semiconductor nanoparticles of the semiconductor nanoparticle-encapsulating vinyl polymer can serve as fillers, thereby enhancing mechanical properties such as tensile strength and modulus of elasticity without lowering impact strength. In particular, in a flexible poly vinylchloride compound manufactured using semiconductor nanoparticles-encapsulating polyvinylchloride and a commercially available phthalate-based low-molecular weight liquid phase plasticizer, a plasticizer migration phenomenon can be prevented by adsorptivity of highly dispersed semiconductor nanoparticles.

A device for testing stability of emulsions and liquid marbles and a method therefor are provided. Aggregation phenomena of liquid drops or the liquid marbles in the emulsions are utilized to test the stability. The method can quickly and accurately test the stability of the emulsions and the liquid marbles.

The invention relates to a preparation method of a perylene pigment. According to the method, the reaction temperature between the organic solvent and solute is firstly preheated at 40-60 DEG C, and the samples are thoroughly mixed and react completely, thereby lowering the temperature increase speed, reducing the aggregation, being beneficial to crystallization, facilitating cleaning and saving the cleaning cost. When the temperature is higher than 70 DEG C, the reaction quickly happens, thereby not being beneficial to the sufficient reaction of the reactants, causing many unreacted substances, not being beneficial to forming crystals with uniform size, and aggravating aggregation; and the prepared product has coarse and large particles, and the aggregation phenomenon is not beneficial to impurity cleaning. The preparation method provided by the invention omits the ball milling after-treatment, and thus, is environment-friendly and economical. The prepared perylene pigment has the advantages of uniform crystal grains, favorable dispersity and high covering power, and thus, can be directly used in paints conveniently.

The invention discloses a metal demolding agent which comprises the following raw materials in parts by weight: 70-90 parts of fluoride graphite, 5-25 parts of graphite, 1-3 parts of a dispersing agent and 0.1-0.5 part of a fluorinated surfactant. The metal demolding agent disclosed by the invention has the main components of fluoride graphite and graphite, the two substances are high in melting point and high in lubrication property, then a dense lubricating membrane can be formed on the surface of a mold, the flowability of a metal in the mold can be improved, and the smoothness and the flatness of the surface of a cast part can be maintained; due to addition of the dispersing agent, not only is the aggregation phenomenon of a powder demolding agent solved, but also the demolding capability of a metal cast part can be improved; due to addition of the fluorinated surfactant, not only is the viscosity of the metal cast part reduced, but also effective spreading of the fluoride graphiteand the graphite can be ensured; through the coordinated use of the substances in a certain ratio, the thermal resistance of the demolding agent can be improved, high chemical stability and excellentlubricating properties can be maintained, and both the cast part and the mold are free of residue.

The invention discloses a method for preventing a pipeline from being blocked by too-wet dressing soil in slope dressing soil dry-spraying operation. The method includes the following steps that firstly, improved dressing soil is prepared, wherein a sand material and vegetable matter are added to the water-contained dressing soil to be stirred and evenly mixed; and secondly, the improved dressing soil is sprayed to a mountain slope beside a road through a dressing soil dry-spraying process. By the adoption of the method, a dressing soil ratio improving method is adopted, bonded particles are effectively scattered, the matrix wall bonding phenomenon is effectively avoided, viscosity is reduced, and the aggregation phenomenon is reduced; the wall bonding phenomenon is reduced; and the pipeline blocking phenomenon generated in dry-spraying operation can be effectively prevented, smooth construction is guaranteed, waste is used, cost is reduced, the soil is evenly sprayed to the slope face of the slope, the construction progress is guaranteed, and the afforesting effect of the slope can be guaranteed.

The invention discloses a preparation method of a surfactant-modified CuInS2 nanocrystal, which comprises the following steps: sequentially adding CuCl2.2H2O, InCl3.4H2O and CH4N2S into an organic solvent, sufficiently dissolving by stirring, adding a surfactant, and evenly mixing, wherein the surfactant is a KH550 silane coupling agent, KH570 silane coupling agent or polyvinyl butyral; transferring the mixture into a pressure kettle, sealing, carrying out thermostatic reaction for 12 hours, and after the reaction finishes, naturally cooling to room temperature; and centrifuging the reaction product, washing and drying. The binary mixed solvent is used instead of the traditional single organic solvent, and the surfactant is added into the mixed reaction system, thereby improving the aggregation phenomenon of the product, and obtaining the nano photovoltaic material which has the advantages of uniform nanosheet structure, high solid yield, favorable light absorption property and proper energy gap.