Abstract: In some embodiments, a method receives a first sequence of inputs for processing via a sub-model of a plurality of sub-model. The plurality of sub-models are part of a main model. An input in the sequence of inputs is masked with a masked value to generate a second sequence of inputs. The method processes the second sequence of inputs using the sub-model to generate a sequence of features that correspond to the second sequence of inputs and processes the sequence of features to generate a first output. The first output is processed to generate a second output of the main model. The sub-model is trained based on a feature in the sequence of features that corresponds to the masked input and the second output.

Abstract: A continuous welding method and device for a hybrid welding, a welded finished product and a train body. The method comprises: performing hybrid welding on a groove of a welding piece by coupling a laser and a variable polarity arc; wherein the defocusing distance of the laser is not less than a Rayleigh length of the laser. According to the method of the present disclosure, the power density of the laser on the surface of the welding piece is effectively reduced and the height-width-ratio of the weld seam is decreased, the diameter of the welding melted pore is increased, the voids caused by the collapse of the small pore in the welding melted pore can be effectively reduced, thereby solving the problem that the weld porosity is difficult to escape in the prior art, and reducing the generation of the pores, effectively improving welding stability and reliability, and improving the mechanical properties of the weld seams.

Abstract: A process for preparing alkylated p-phenylenediamine having the steps of reacting aniline and nitrobenzene in presence of a complex base catalyst to obtain 4-aminodiphenylamine intermediates, hydrogenating the 4-aminodiphenylamine intermediates to 4-aminodiphenylamine in presence of a hydrogenation catalyst, and reductively alkylating the 4-aminodiphenylamine to alkylated p-phenylenediamine.

Abstract: A method for refining an organic composition containing 4-aminodiphenylamine, aniline, azobenzene, and phenazine, having the steps of feeding the organic composition to a first rectification column, producing a first effluent composition containing aniline, azobenzene, phenazine, and a small amount of 4-aminodiphenylamine at the top of the first rectification column and a second effluent composition containing crude 4-aminodiphenylamine at the bottom of the first rectification column, feeding the second effluent composition to a second rectification column, and producing a 4-aminodiphenylamine composition at the top of the second rectification column and a residual composition at the bottom of the second rectification column.

Abstract: A falling film evaporator having a shell pass, multiple tubes parallel to each other, a condensed steam outlet, an inlet for an aqueous solution on the top of the tube pass, an outlet for the aqueous solution at the bottom of the tube pass, a distributing assembly having a plurality of distributing trays arranged vertically from top to bottom in incremental diameters and each having multiple holes, and a plate for collecting the aqueous solution below the distributing assembly. The tubes are straight and installed vertically in the evaporator; inner wall of the tubes is smooth, and the top portion of the tubes is protruded above a horizontal plane of the plate. The evaporator is particularly useful for concentrating an aqueous solution containing thermosensitive materials.

Abstract: A process for preparing alkylated p-phenylenediamine having the steps of reacting aniline and nitrobenzene in presence of a complex base catalyst to obtain 4-aminodiphenylamine intermediates, hydrogenating the 4-aminodiphenylamine intermediates to 4-aminodiphenylamine in presence of a hydrogenation catalyst, and reductively alkylating the 4-aminodiphenylamine to alkylated p-phenylenediamine.

Abstract: The present invention provides spherical rubber chemicals and the method for preparing the same. The spherical rubber chemicals of the present invention include spherical antioxidants, spherical vulcanization agents, spherical processing aids, spherical reinforcing agents, or spherical adhesive agents. With the spherical rubber chemicals of the present invention, the shortcomings of powdery or semi-spherical rubber chemicals are overcome, including eliminating the dust pollution during granulation procedure and avoiding the raw material loss and the environmental pollution, while solving the quality problem of lower melting point of product caused by the presence of fine powder crystal. Furthermore, the resultant rubber chemicals has an improved smoothness of surface, which is helpful to improve the flowing and mixing behaviors of the rubber chemicals in mixing or open milling process with rubbers.

Abstract: A complex base catalyst comprising tetraalkyl ammonium hydroxide and tetraalkyl ammonium salt for the condensation reaction of aniline and nitrobenzene.

Abstract: The present invention relates to a magnetic separation apparatus for continuous separating and recovering magnetic solid particles from a solid-liquid mixture. The apparatus includes at least one magnetic separation unit and each unit includes: an outer cylindrical vessel having a material inlet, a first outlet, and a second outlet; an inner cylindrical vessel, at least part of which extends along the axis inside the first cylindrical vessel without contacting with the inner surface of the outer cylindrical vessel; and a magnet, rendering the bottom of the inner cylindrical vessel magnetism during the first period and making the part of the surface lose its magnetism during a second period. When the solid-liquid mixture flows through the magnetic surface of the inner cylindrical vessel in the passage, the magnetic solids are absorbed and separated from the mixture.

Abstract: The present invention provides spherical rubber chemicals and the method for preparing the same. The spherical rubber chemicals of the present invention include spherical antioxidants, spherical vulcanization agents, spherical processing aids, spherical reinforcing agents, or spherical adhesive agents. With the spherical rubber chemicals of the present invention, the shortcomings of powdery or semi-spherical rubber chemicals are overcome, including eliminating the dust pollution during granulation procedure and avoiding the raw material loss and the environmental pollution, while solving the quality problem of lower melting point of product caused by the presence of fine powder crystal. Furthermore, the resultant rubber chemicals has an improved smoothness of surface, which is helpful to improve the flowing and mixing behaviors of the rubber chemicals in mixing or open milling process with rubbers.

Abstract: A method for refining an organic composition containing 4-aminodiphenylamine, aniline, azobenzene, and phenazine, having the steps of feeding the organic composition to a first rectification column, producing a first effluent composition containing aniline, azobenzene, phenazine, and a small amount of 4-aminodiphenylamine at the top of the first rectification column and a second effluent composition containing crude 4-aminodiphenylamine at the bottom of the first rectification column, feeding the second effluent composition to a second rectification column, and producing a 4-aminodiphenylamine composition at the top of the second rectification column and a residual composition at the bottom of the second rectification column.

Abstract: The present invention provides spherical rubber chemicals and the method for preparing the same. The spherical rubber chemicals of the present invention include spherical antioxidants, spherical vulcanization agents, spherical processing aids, spherical reinforcing agents, or spherical adhesive agents. With the spherical rubber chemicals of the present invention, the shortcomings of powdery or semi-spherical rubber chemicals are overcome, including eliminating the dust pollution during granulation procedure and avoiding the raw material loss and the environmental pollution, while solving the quality problem of lower melting point of product caused by the presence of fine powder crystal. Furthermore, the resultant rubber chemicals has an improved smoothness of surface, which is helpful to improve the flowing and mixing behaviors of the rubber chemicals in mixing or open milling process with rubbers.

Abstract: A falling film evaporator having a shell pass, multiple tubes parallel to each other, a condensed steam outlet, an inlet for an aqueous solution on the top of the tube pass, an outlet for the aqueous solution at the bottom of the tube pass, a distributing assembly having a plurality of distributing trays arranged vertically from top to bottom in incremental diameters and each having multiple holes, and a plate for collecting the aqueous solution below the distributing assembly. The tubes are straight and installed vertically in the evaporator; inner wall of the tubes is smooth, and the top portion of the tubes is protruded above a horizontal plane of the plate. The evaporator is particularly useful for concentrating an aqueous solution containing thermosensitive materials.

Abstract: A process for preparing 4-aminodiphenylamine having the steps of reacting nitrobenzene and aniline in the presence of a complex base catalyst, hydrogenating the reaction mixture with hydrogen, a powdery composite catalyst, and a hydrogenation solvent; separating, recovering, and reusing the complex base catalyst and the powdery composite catalyst from the reaction mixture; separating, recovering, and reusing aniline, and optionally water, from the reaction mixture; refining the reaction mixture to obtain 4-aminodiphenylamine. The complex base catalyst comprises tetraalkyl ammonium hydroxide, and tetraalkyl ammonium salt.

Abstract: The present invention provides spherical rubber chemicals and the method for preparing the same. The spherical rubber chemicals of the present invention include spherical antioxidants, spherical vulcanization agents, spherical processing aids, spherical reinforcing agents, or spherical adhesive agents. With the spherical rubber chemicals of the present invention, the shortcomings of powdery or semi-spherical rubber chemicals are overcome, including eliminating the dust pollution during granulation procedure and avoiding the raw material loss and the environmental pollution, while solving the quality problem of lower melting point of product caused by the presence of fine powder crystal. Furthermore, the resultant rubber chemicals has an improved smoothness of surface, which is helpful to improve the flowing and mixing behaviors of the rubber chemicals in mixing or open milling process with rubbers.

Abstract: The present invention relates to a magnetic separation apparatus for continuous separating and recovering magnetic solid particles from a solid-liquid mixture. The apparatus includes at least one magnetic separation unit and each unit includes: an outer cylindrical vessel having a material inlet, a first outlet, and a second outlet; an inner cylindrical vessel, at least part of which extends along the axis inside the first cylindrical vessel without contacting with the inner surface of the outer cylindrical vessel; and a magnet, rendering the bottom of the inner cylindrical vessel magnetism during the first period and making the part of the surface lose its magnetism during a second period. When the solid-liquid mixture flows through the magnetic surface of the inner cylindrical vessel in the passage, the magnetic solids are absorbed and separated from the mixture.

Abstract: A process for preparing 4-aminodiphenylamine having the steps of reacting nitrobenzene and aniline in the presence of a complex base catalyst, hydrogenating the reaction mixture with hydrogen, a powdery composite catalyst, and a hydrogenation solvent; separating, recovering, and reusing the complex base catalyst and the powdery composite catalyst from the reaction mixture; separating, recovering, and reusing aniline, and optionally water, from the reaction mixture; refining the reaction mixture to obtain 4-aminodiphenylamine. The complex base catalyst comprises tetraalkyl ammonium hydroxide, and tetraalkyl ammonium salt.

Abstract: A process for preparing 4-aminodiphenylamine having the steps of reacting nitrobenzene and aniline in the presence of a complex base catalyst, hydrogenating the reaction mixture with hydrogen, a powdery composite catalyst, and a hydrogenation solvent; separating, recovering, and reusing the complex base catalyst and the powdery composite catalyst from the reaction mixture; separating, recovering, and reusing aniline, and optionally water, from the reaction mixture; refining the reaction mixture to obtain 4-aminodiphenylamine. The complex base catalyst comprises tetraalkyl ammonium hydroxide, and tetraalkyl ammonium salt.

Abstract: A complex base catalyst comprising tetraalkyl ammonium hydroxide and tetraalkyl ammonium salt for the condensation reaction of aniline and nitrobenzene.

Abstract: A falling film evaporator having a shell pass, a tube pass, a steam inlet on top of the shell pass, a condensed water outlet at bottom of the shell pass, a lower concentration aqueous phase inlet on top of the tube pass, a higher concentration aqueous phase outlet at bottom of the tube pass, a flow-aiding steam inlet on top of the tube pass, and a distributing tray below the lower concentration aqueous phase inlet.