31results about How to "Avoid the introduction of impurities" patented technology

The invention discloses a sodium sulfite solution preparation tank for chlor-alkali and a preparation system, belonging to the technical field of preparation of sodium sulfite solution for chlor-alkali. In the present invention, after the protective gas connection port is set on the preparation tank body, the protective gas can be passed into the preparation tank body after being connected with the protective gas supply device, thereby reducing the oxidation of the sodium sulfite solution during the preparation process. Moreover, since the sodium sulfite solution in the configuration process will not be oxidized, the configured sodium sulfite solution can be directly stored in the configuration tank body without the need to separately set up a special storage tank structure, and it can be stored for a long time; therefore, since there is no storage tank structure, and can be stored for a long time, so the volume of the preparation tank body can be increased to reduce the frequency of preparation. At the same time, the main part of the entire preparation tank body can be installed below the ground to avoid manual transportation to high places and reduce labor intensity.

The invention discloses a method for preparing a revolving body of high-strength and high-purity carbon / carbon composite material by winding. The method comprises: 1. preparing a mandrel; 3. Perform chemical vapor deposition densification on dry yarn prefabricated parts to form deposition parts; 4. Repeat dry yarn winding process and chemical vapor deposition densification process to form carbon / carbon densification parts; 5. Carbon / carbon densification parts are treated at high temperature Obtain a high-temperature treatment part; 6. Prepare a pyrolytic carbon or silicon carbide coating on the surface of the high-temperature treatment part after demoulding to obtain a carbon / carbon composite material revolving body. The present invention adopts the method of graded winding molding-chemical vapor infiltration densification, which shortens the gas diffusion path of chemical vapor infiltration densification, thereby avoiding the phenomenon that the surface density of the deposit body increases faster than that of the interior, and improves the rotation of carbon / carbon composite materials. The bonding strength of the interface between the bulk layers improves the quality and purity of the product, and is used in photovoltaics, semiconductors and other fields.

The invention proposes a method for processing a silicon-based substrate, comprising: obtaining a silicon wafer; chemically treating the silicon wafer to form a hydrogen passivation layer on the surface of the silicon wafer; performing a desorption process on the silicon wafer to remove hydrogen passivation layer. According to the silicon-based substrate processing method of the embodiment of the present invention, after the silicon wafer is chemically treated, a hydrogen passivation layer is formed on the surface of the silicon wafer, which can effectively protect the silicon wafer. Moreover, the desorption temperature of the hydrogen passivation layer is relatively low, thereby effectively reducing the problem of bending damage and introducing impurities caused by the high-temperature desorption of the passivation layer on the silicon wafer. Moreover, when selecting a silicon wafer, optimize the silicon Chip screening standards, thereby effectively reducing the flatness of silicon-based substrates, improving the processing quality of silicon-based substrates, and facilitating the processing of large area array devices.

The invention discloses a method-static shearing method for detecting the kiln coating suspension performance of a fireproof brick for a cement kiln, and a principle, equipment, a sample, steps and result calculation thereof. The static shearing method is low in experimental expense, strong in operability and quantizable, especially the shearing position is proper, the data is stable and good in repeatability in the shearing range, the influence caused by errors is greatly reduced, the practical kiln coating suspension performance of the fireproof brick for the cement kiln can be really reflected, the conventional fireproof material detection equipment is made full use of, and the conventional performance detection method for the fireproof brick is further improved.

The invention provides a TiAl alloy powder and its preparation method and application, belonging to the technical field of metal powder. The TiAl alloy powder includes the following elements by mass percentage: Al: 34%-35%, Nb: 4.5%-5.1%, Cr: 2.4%-2.7%, Gd: 0-0.02%, C: greater than 0 and not greater than 150ppm, N: more than 0 and not more than 200ppm, H: more than 0 and not more than 100ppm, O: more than 0 and not more than 700ppm, the balance being Ti; the TiAl alloy powder is spherical, with a particle size of 40μm-106μm, flowing The resistance is 10.0~20.0s / 50g, and the hollow ball rate is not more than 0.5%.

The invention relates to the technical field of pharmaceutical preparations, and specifically discloses a compound electrolyte injection and a preparation method thereof. The preparation method is as follows: adding L-malic acid, magnesium chloride, sodium chloride, potassium chloride, calcium chloride, sodium acetate and sodium hydroxide in the prescribed quantity into the water for injection prepared with a total volume of 70-80% in sequence , stir and dissolve, heat to boil, keep for 10min-20min, add water for injection to the total amount of preparation, filter through multi-stage polyethersulfone filter elements with successively smaller pore diameters, fill, and sterilize to obtain compound electrolyte injection. The present invention prepares the compound electrolyte injection (II) with significantly reduced impurity types and contents through a one-step preparation method, which significantly improves the storage stability of the injection, and the impurity content does not increase significantly in the stability investigation test, and at the same time, The production process is greatly simplified, the production efficiency is improved, the production cost is reduced, the industrialized production is facilitated, and the invention has broad application prospects.

The invention discloses an AlGaN film with an in-situ SiN dislocation annihilation layer and an epitaxial growth method thereof. The steps of the method include: epitaxially growing an AlN film on a sapphire substrate; epitaxially growing a first AlGaN thin film layer; using hydrogen gas to etch dislocation pits on the first AlGaN thin film layer; in-situ depositing a SiN dislocation annihilation layer on the surface of the dislocation pit; epitaxially growing a second dislocation annihilation layer on the SiN dislocation annihilation layer AlGaN thin film layer. In the present invention, by corroding dislocation pits on the first AlGaN thin film layer and then performing SiN in-situ filling, on the one hand, the second AlGaN thin film layer and subsequent film layers can be patterned synchronously during the growth process, It avoids the problem of taking out the epitaxial wafer for complex etching process and introducing impurities during taking out the etching; on the other hand, since the SiN dislocation annihilation layer is an island-like distribution structure corresponding to the dislocation pit, this structure is more conducive to Growth healing of the second AlGaN film layer.

The invention discloses an atomization assembly applied to an opening of a container. The atomization assembly comprises a first air inlet pipeline, a liquid inlet pipeline, a mist outlet pipeline, a U-shaped air inlet pipeline and an atomization separation chamber, wherein the first air inlet pipeline is connected with one end of the U-shaped air inlet pipeline; the liquid inlet pipeline and the atomization separation chamber mutually communicate with the other end of the U-shaped air inlet pipeline; and the atomization separation chamber communicates with the mist outlet pipeline. The invention further discloses an atomization device. The atomization device comprises the sealable container and the atomization assembly. With the adoption of the U-shaped air inlet pipeline, the atomization assembly disclosed by the invention is compact in structure and capable of being arranged at the opening of the container. Therefore, on one hand, the structure is simplified, the occupied volume of the device is greatly reduced, and assembly steps are simplified; and on the other hand, the atomization assembly is disposable, thus the safety of liquid use is greatly improved.