8results about How to "Improve compromise" patented technology

The present invention relates to an IGBT device with a thyristor structure using self-biased MOS clamping, which can also be regarded as an integrated ETO device. The body region of the IGBT device is composed of multiple layers of P-type doped layers and N-type doped layers arranged alternately, and adjacent doped regions of the same conductive type are completely isolated by another conductive type doped region. The device of the present invention uses a self-biased MOS (Q2) to clamp the electric field shielding layer, so that the external control MOS (Q1, Q2) of the traditional ETO can be monolithically integrated into the device. At the same time, compared with the IGBT with a carrier storage layer, the self-biased MOS (Q2) clamps the drain potential of the MOS (Q1) in the structure of the present invention at a lower level, thereby greatly improving the doping concentration threshold of the carrier storage layer and reducing the on-state voltage drop of the device; and the clamped MOS drain potential can reduce the saturation current of the new structure, thereby increasing the short-circuit safe working area of ​​the new device.

The present invention provides a design method for an adjustable steam seal and spring sheet for a steam turbine, and relates to the field of steam seals for steam turbines. The scheme adopted is: comprising a steam seal body and a steam seal ring, the steam seal ring is a segmented structure, comprising at least 4 steam seal arc segments, the steam seal body is provided with a mounting groove, a spring sheet is provided between the steam seal body and the steam seal ring, the spring sheet comprises a fixed end, a middle part and a free end in sequence, the widths of the fixed end, the middle part and the free end are all the same, the fixed end and the free end are both arc-shaped structures, the middle part is a straight structure, a slot is provided on the steam seal arc segment, the fixed end is inserted into the slot, the fixed end and the free end are both in contact with the top of the steam seal body cavity, the middle part can slide along the steam seal arc segment, a limiting plate is also provided on the steam seal arc segment, and the two ends of the limiting plate can be in contact with the steps of the mounting groove. The present invention can effectively maintain the minimum gap between the dynamic and static parts of the steam turbine, the good yield and sealing properties of the steam seal ring, and at the same time, the spring sheet is not easy to break and has a long service life.

Structure (10) comprising at least one device (1) connectable to at least one wall (11) of the structure (10), comprising a first and a second metal profiles (2, 3), the first metal profile (2) defining in section at least one first closed chamber (4), the second metal profile (3) defining in section at least one second closed chamber (5) comprising a polymer insulating element (7) which is interposed between the first metal profile (2) and the second metal profile (3), said first metal profile (2), said polymer insulating element (7) and said second metal profile (3) being arranged in series, so as to prevent the contact between the first metal profile (2) and the second metal profile (3) characterized in that said structure (10) defines at least one inner space and one outer space of the structure (10), wherein said first metal profile (2) faces the outer space and said second metal profile (3) faces the inner space and in that said second metal profile (3) comprises two or more chambers (5, 6), wherein said second metal profile (3) is a single element forming in section said two or more chambers (5, 6), wherein said second metal profile (3) is covered by a polymer cover (8) that faces the inner space.

A ceramic composite pipe for desulfurization and its manufacturing process belong to the field of powder metallurgy preparation of composite pipes. A first pre-bonding layer is formed by spraying a slurry containing metal-based powder and a binder on the outer surface of a ceramic liner pipe, and a slurry containing a high melting point powder and a binder is sprayed on the outer surface of the first pre-bonding layer to form a second pre-bonding layer. Then, the metal matrix pipe and the ceramic liner pipe are assembled into a preform with the metal matrix pipe as the outer layer and the ceramic liner pipe as the inner layer. The preform is sintered to form a porous metallurgical sintering layer in the first pre-bonding layer, and a bonding sintering layer in the second pre-bonding layer. The present invention adopts a powder metallurgy composite process to manufacture a composite pipe, which simplifies the manufacturing process. The porous metallurgical sintering layer can ensure the combination with the ceramic liner pipe. The bonding sintering layer provides yielding properties while allowing a part of the low melting point metal in the porous metallurgical sintering layer to penetrate and form a metallurgical overlap point with the metal matrix pipe of the outer layer, thereby ensuring the composite strength of the inner and outer pipes.

This invention relates to the field of precision casting of high-temperature alloy blades, and particularly to the field of preparing precision casting mold shells for aircraft single-crystal blades. The invention involves mixing different types of fused mullite powder and corundum powder with silica sol of varying specifications to form a slurry, which is then combined with corundum sand or fused mullite sand of different mesh sizes to prepare the mold shell. After dewaxing and calcination, the mold shell is obtained for preparing single-crystal turbine blades. The single-crystal blade mold shell prepared by this invention can effectively prevent recrystallization on the blade surface, reduce the blade recrystallization scrap rate, and save production costs.

The production method for improving the magnetic powder inspection qualification rate of the nickel-containing low-alloy steel castings comprises the following process steps of shell making, shell roasting and pouring, renovating, heat treatment, primary catenary sanding, acid pickling and secondary catenary sanding, a graphite sand shell is adopted, oxidation of molten steel in the cooling process after pouring is greatly reduced, and the yield of the molten steel is improved. The nickel-containing low-alloy steel casting is subjected to heat treatment by adopting an inert gas shielding method, oxide skin formation can be effectively prevented, the heating efficiency is improved, so that the quality of the casting is improved, a groove type soaking and pickling process is arranged between primary catenary sanding and secondary catenary sanding, and the oxide skin on the surface of the casting can be thoroughly removed. According to the production process adopted by the invention, the defects of slag inclusion, air holes, pits, flow lines and the like of the nickel-containing low-alloy steel casting are greatly reduced, oxide skin on the surface of the casting can be thoroughly removed, the casting quality is greatly improved, the magnetic powder detection qualification rate is greatly improved, delay of delivery time due to multiple times of repair is avoided, the product rejection rate is also reduced, and the production cost is reduced. And obvious economic benefits can be brought to enterprises.

The present invention relates to the technical field of investment casting, and in particular to a silica sol mold shell and a preparation method thereof. The preparation method of the silica sol mold shell of the present invention comprises: the mold group is sequentially subjected to the steps of dip coating of a surface layer, sprinkling of a surface layer sand, dip coating of a transition layer, sprinkling of a transition layer sand, dip coating of a reinforcement layer, sprinkling of a reinforcement layer sand and dip coating of a sealing layer to obtain a mold shell; the mold shell is dewaxed and roasted to obtain the silica sol mold shell; wherein the transition layer coating comprises, by weight, 800 to 1000 parts of mullite powder, 0.8 to 1.2 parts of carbon fiber and 480 to 520 parts of silica sol; the reinforcement layer coating comprises, by weight, 1400 to 1800 parts of mullite powder, 0.8 to 1.2 parts of carbon fiber and 480 to 520 parts of silica sol. The method can reduce the thickness of the mold shell while maintaining its strength and increase the air permeability of the mold shell.

The invention provides a semiconductor device and a manufacturing method thereof. The manufacturing method comprises the following steps: providing a substrate; forming a gate dielectric layer on the upper surface of the substrate, and forming a gate field plate dielectric layer at a preset position above the gate dielectric layer; a gate structure is formed, the gate structure comprises a gate electrode and a gate field plate which are connected, the gate electrode is located above the gate dielectric layer, the gate field plate is located above the gate field plate dielectric layer, and the distance between the gate field plate and the device drain region is smaller than the distance between the gate electrode and the device drain region in the horizontal direction. The electric field intensity of one end, facing the drain region of the device, of the gate structure is reduced, and high current density can be obtained while the hot carrier injection effect is reduced; in addition, the drift region is formed in a photoetching-free mode before the gate structure is prepared, the technological process is simplified, and the requirement for the alignment precision of the gate field plate technology is lowered. In addition, the gate field plate dielectric layer is prepared through a self-stop etching method, and the process is simple and controllable.