1058 results about "Vacuum pressure" patented technology

A filtration system for a dry bulk tank trailer includes a filter canister containing a filter media in the interior volume of the filter canister. The filter media divides the interior volume of the filter canister into a dusty air side and a clean air side of the interior volume on opposite sides of the filter media. A dusty air line operatively communicates the dusty air side of the interior volume with the dry bulk tank. A fitting operatively communicates with the clean air side of the interior volume. The fitting is operable to selectively communicate a vacuum pressure and a positive pressure to the clean air side of the interior volume.

The invention discloses a low-vacuum circulating water heating dynamic load matching method based on AI regulation and control, and the method comprises the following steps: step S100, multi-source data real-time collection: building thermal environment parameters are synchronously collected through a temperature sensor array, a vacuum pressure transmitter, a flowmeter and an environment monitoring unit which are deployed in a distributed manner; according to the method, the control period is compressed to the minute level, compared with traditional PID control, the response speed is increased by several times, the indoor temperature can be controlled more accurately, and meanwhile the failure rate of equipment is reduced. According to the sudden weather coping mechanism, heat supply strengthening can be started 30 minutes ahead of time under extreme weather such as snowstorm weather, and the stability of the system is ensured. The method is characterized in that the prediction advantage of deep learning and the optimization capability of model prediction control are deeply combined, and the control problem of multivariable strong coupling of the low vacuum system is solved through a verification system of multi-source data fusion and virtual-real combination.

In an embodiment, a method for detecting leaks in a shaft of a cryoablation system includes placing a vacuum pump in fluid communication with a return tube and a supply tube; pulling a vacuum within the supply tube and the return tube; after pulling the vacuum for a predetermined amount of time, measuring a vacuum pressure within the supply tube and the return tube; and analysis of the vacuum pressure to assist with identifying leaks in the system.

The invention discloses active brazing filler metal for sealing sapphire and kovar alloy and a preparation method of the active brazing filler metal. The active brazing filler metal comprises 25.0 wt%-27.5 wt% of Cu, 1.0 wt%-6.0 wt% of Ti, 1.0 wt%-5.0 wt% of Al, 0.1 wt%-1.0 wt% of B, 0.1 wt%-0.5 wt% of rare earth element RE, RE is one or more of La, Ce, Sc, Pr, Nd and Er, and the balance is Ag. The preparation method comprises the following steps: preparing silver-based pre-alloying powder by adopting a gas atomization method, mixing the alloy powder with additive element powder in a ball milling manner, sintering by utilizing vacuum pressure to obtain an alloy ingot blank, and carrying out rough rolling, intermediate annealing and finish rolling to obtain an active brazing filler metal strip with the thickness of 0.05-0.2 mm. The active brazing filler metal is well matched with the thermal expansion coefficient of sapphire, direct brazing of sapphire and Kovar alloy can be achieved, the brazing temperature is moderate, and a brazed joint is uniform in structure and free of defects such as air holes and cracks.

The invention discloses a vacuum pressure impregnation mold assembly process and a mold. The process comprises the following steps: mounting bottom hard molds on a plurality of independent supporting platforms, and then positioning superconducting coils; descending the platform in sections to lay a bottom soft mold and a flow guide component to ensure uniform gaps; the side edge soft mold, the side edge hard mold, the top flow guide net and the soft and hard mold are sequentially installed, and finally the soft mold is subjected to segmented welding and the hard mold is reinstalled. The mold is assembled through the method, and modular assembly is achieved by lifting the independent supporting platform in stages. According to the process, the load of a single platform is reduced through sectional assembly, precision deviation and equipment damage are avoided, and meanwhile, the use of a lifting appliance is reduced to protect the dimensional stability of the coil; a soft and hard mold layered assembly mode is adopted, the machining difficulty of a large-size mold is simplified, the manufacturing cost is reduced, and the size control precision is improved; the step-by-step assembly process effectively reduces the wrong assembly risk, avoids the problem of glue injection port blockage, and ensures the success rate of the vacuum pressure impregnation process.

The invention discloses a wafer vapor deposition device and a use method, and the wafer vapor deposition device comprises a wafer box lifting device which is used for lifting a wafer box; the load locking chamber is arranged between the reaction chamber and the wafer box lifting device, and a wafer cache structure is arranged in the load locking chamber; the wafer cache structure is used for storing wafers which are not subjected to film deposition and transferred from the wafer box to the reaction chamber or storing wafers which are subjected to film deposition and transferred from the reaction chamber to the wafer box; the reaction chambers are used for performing thin film deposition on the wafer; and the wafer transfer device is used for transferring wafers among the wafer box, the wafer cache structure and the reaction chamber. The opening and closing frequency of the load locking cavity is obviously reduced, frequent conversion between atmospheric pressure and vacuum pressure is avoided, the production efficiency is improved, and the operation pressure of a vacuum pumping system is effectively relieved.

A vacuum drying apparatus has a rigid bin structure within a flexible membrane liner arranged to store particulate material therein. An exhaust passage and air inlet passage communicate through the envelope in sealed relationship with the envelope. The air inlet passage is adjustably flow restricted relative to the exhaust passage so as to enable a flow through material in the liner when applying vacuum pressure to the exhaust passage, for example using a centrifugal fan. The air inlet passage communicating with an upper manifold within the upper portion of the bin structure and the exhaust passage communicating with a lower manifold within a lower portion of the bin structure.

The invention relates to the technical field of image data processing, and discloses an element mounting quality detection method for a chip mounter, which comprises the following steps of: synchronously acquiring images before and after element mounting and a vacuum pressure signal of a mounting suction nozzle, compensating vibration by utilizing an inherent substrate background area in the images, obtaining an optical position deviation through image difference and mass center calculation, and calculating the surface mounting quality of the element according to the optical position deviation. And finally, logically associating the deviation with the change characteristic of the pressure signal, and classifying the physical process of the mounting event. According to the invention, through the collaborative diagnosis of optical detection and physical signals, the physical reason of the mounting event can be clearly distinguished; the inherent limitation caused by vibration interference and unclear fault attribution during high-speed operation of a traditional detection mode is avoided, and the method has good adaptability to incoming material elements with different appearances.

The invention relates to a bionic Al / SiC composite material with a three-dimensional network multilevel structure and a preparation method of the bionic Al / SiC composite material, and belongs to the technical field of new material preparation. According to the method, through the collaborative process of freeze casting and organic foam impregnation, the problem that in the prior art, the multilevel aperture and the complex network structure are difficult to cooperatively regulate and control is solved. The preparation method comprises the following specific steps: preparing tert-butyl alcohol-based ceramic slurry, impregnating the slurry with polyurethane foam, performing freeze casting molding, removing a solvent through freeze drying, performing high-temperature sintering to form SiC ceramic with a three-dimensional reticular hierarchical pore structure, and finally preparing the Al / SiC composite material through a vacuum pressure infiltration process. Wherein a sintering aid is added into the slurry, so that the sintering temperature is obviously reduced; the specification (40-60 ppi) of polyurethane foam, the solid phase content (20-30 vol.%) of slurry, the freezing speed (0-90 DEG C) and the content (5-20 wt.%) of a sintering aid are regulated and controlled. And the cross-scale collaborative design of micron-scale directional holes and millimeter-scale mesh holes is realized. The Al / SiC composite material prepared by the invention has the advantages that the compressive strength, fracture toughness and other properties are obviously higher than those of the traditional single-aperture porous ceramic, and the Al / SiC composite material is suitable for the fields of manufacturing and energy absorption of precise instruments, electronic packaging and optical devices.

The invention relates to the technical field of vacuum coating, and particularly discloses a control system for a vacuum coating machine, which comprises a vacuum stable state analysis module, a gas flow matching analysis module, a coating environment control analysis module and a coating parameter control analysis module. Pressure intensity values of monitoring time points in all control time periods are accurately collected through a capacitive pressure sensor, the average value of the pressure intensity is calculated, the overall level of the vacuum pressure intensity in the time period can be visually reflected, and basic data are provided for judging whether the vacuum degree is in a proper range or not; an active monitoring and prevention mechanism is adopted for the vacuum coating machine, so that the continuity and the stability of coating production are guaranteed, a scientific basis is provided for preventive maintenance of the equipment, the service life of the equipment is prolonged, the probability of sudden failure of the equipment is reduced, the reliability, the high efficiency and the intelligent level of the whole vacuum coating production system are improved, and the production cost is reduced. And the competitiveness of enterprises in the field of coating processing is improved, the production cost is reduced, and the product quality is improved.

The invention relates to the technical field of reactor thermal hydraulics and safety, in particular to a long electric heating plate heat insulation structure and a heat transfer simulation experiment device with the long electric heating plate heat insulation structure. The long electric heating plate heat insulation structure comprises a heat insulation base, a heating plate and a cementing layer. The heat insulation base is configured to be a ceramic resin plate, and a sinking groove is formed in one plate face of the heat insulation base. The heated plate is arranged in the sinking groove so that the plate face of the heated plate can be flush with the plate face of the heat insulation base, and the surface, corresponding to the groove wall and the groove bottom of the sinking groove, of the heated plate is provided with a micropore aluminum oxide ceramic layer which is subjected to nanocrystallization treatment through an active coupling agent. And the cementing layer is arranged between the heated plate and the heat insulation base in a high-temperature vacuum pressure environment. According to the heat transfer simulation experiment device, it can be ensured that the heated plate has good single-side heat dissipation performance under the temperature working condition that the surface of the dispersion type fuel element is blistered, the experiment safety during operation of the heat transfer simulation experiment device can be ensured, and the accuracy of a measurement result in a simulation experiment can be ensured.

The invention discloses a wafer bonding method, which comprises the following steps of: 1, providing a first wafer and a second wafer, the surface of the first wafer being provided with a microstructure with a high aspect ratio; step 2, cleaning the first wafer and the second wafer; step 3, performing vacuum drying treatment on the first wafer and the second wafer, wherein the vacuum pressure is controlled to be 0.1-10 Torr in the vacuum drying treatment process; step 4, carrying out pre-bonding on the first wafer and the second wafer to form a bonding body; and step 5, carrying out annealing treatment on the bonding body. Aiming at the problem of residual water in the pre-cleaning process in the bonding process of the micro-structure wafer with a high aspect ratio, the wafer is placed in a controllable vacuum environment, phase change boiling of liquid water under the condition of no heat input is realized, and the problem of high-temperature heat damage caused by an existing heating and baking method is effectively avoided.

The invention discloses a high-strength and high-elongation SnPbSbInAu alloy solder and a preparation method thereof. The alloy solder comprises the following components in percentage by weight: 33.0 to 36.5 percent of Pb, 2.0 to 4.0 percent of Sb, 1.5 to 3.5 percent of In, 2.0 to 3.5 percent of Au, 0.005 to 0.012 percent of P and the balance of Sn. The preparation method of the foil strip comprises the steps of vacuum pressure casting, strip cold extrusion and cold roller rolling, the wire preparation method comprises the steps of one-time extrusion forming and close-packed rewinding, and the powder paste preparation method comprises the steps of vacuum gas atomization powder preparation, airflow screening and planetary centrifugal degassing paste preparation. The solid-liquid phase temperature of the solder ranges from 180 DEG C to 185 DEG C, the solder has the advantages of being high in ductility, strength and creep resistance, excellent in low-temperature service performance and the like, and the tensile strength of a brazed joint of the solder is two times higher than that of a Sn-37Pb eutectic solder under the same welding process; and the gold etching risk is low, and a gold-plated piece can be directly welded (without tinning treatment).

An immersion brewing device and method of using same are disclosed. The brewing device comprises a body, a lid, a basket contained within the body, a pull-up means for creating vacuum pressure within the body, an agitator coupled to the pull-up means and detachably coupled to the basket, and a locking means for locking the agitator to the pull-up means. The pull-up means comprises a main shaft having a top and an opposing bottom, a spinner cap disposed about the top of the main shaft, and a wingnut rotatably disposed about the main shaft. The agitator comprises one or more flat blades angled to create a helicopter-blade-like-movement. The locking means comprises a detent and a detent channel adapted to receive the detent, wherein the detent is disposed about one end of each blade, and wherein the detent channel is cut into the basket.

A method of processing a substrate comprising: positioning the substrate on an upper surface of a substrate holder in a first chamber, wherein the substrate holder comprises one or more vacuum channels disposed at the upper surface and one or more electrodes disposed within the substrate holder proximate to the upper surface; while the substrate holder is within the first chamber, clamping and flattening the substrate to the substrate holder by applying a vacuum to the one or more vacuum channels; while the substrate is clamped to the substrate holder via the one or more vacuum channels, applying a voltage to the one or more electrodes to further clamp the substrate to the substrate holder with an electrostatic force; pumping out the first chamber to a vacuum pressure while continuing to clamp the substrate to the substrate holder with electrostatic force; while the substrate is clamped to the substrate holder by electrostatic force, transferring the substrate holder from the first chamber into a second chamber under vacuum conditions; and while the substrate holder is within the second chamber, maintaining the electrostatic force clamping the substrate to the substrate holder, and processing the substrate in the second chamber at a vacuum pressure.

The invention relates to the technical field of superconducting magnet manufacturing and insulation impregnation process optimization, and discloses a vacuum pressure impregnation process optimization method, device, equipment, medium and product, and the method comprises the steps: inputting a target porosity and a target permeability into an insulation layer homogenization fluid domain model to obtain a macroscopic homogeneous model; according to the macroscopic homogeneous model, a first corresponding relation between multiple technological parameters and the impregnation performance parameters under the boundary condition is determined through simulation, and the multiple technological parameters comprise at least two of the temperature, the glue injection parameter, the vacuum pressure, the resin viscosity and the resin curing kinetic parameter; and according to the plurality of first corresponding relations, optimizing the plurality of process parameters by taking the shortest filling time, the highest uniformity and the lowest residual bubble rate as optimization objectives to obtain an optimal process parameter combination of the vacuum pressure impregnation process. According to the method, the multiple process parameters are optimized, the multi-parameter optimization database can be established, and the optimal process combination scheme is obtained.

The invention provides a PID self-tuning vacuum pressure adjusting device. The PID self-tuning vacuum pressure adjusting device comprises a human-computer interface, an external interface, a control unit, a pressure acquisition module, a PID self-tuning unit, a power execution unit and a valve, the PID self-tuning unit realizes a pressure adjustment function, is different from a conventional PID adjustment algorithm, has the capability of automatically correcting PID parameters, outputs a valve position adjustment value, controls the pressure to quickly approach a target position, and reduces steady-state errors. The power execution unit receives the target valve position, and a driving motor drives a speed reducer to run to the target position; the valve department controls the through-flow area of the pipeline so as to adjust the pressure value of the pipeline. By the adoption of the device, for the vacuum pressure adjusting technology with hysteresis quality, the pressure of the cavity can be adjusted more accurately, steady-state errors are smaller, fluid waste caused by fluctuation is reduced, equipment can be separated from a PLC to operate independently according to a preset target value, flexibility is higher, and the equipment cost can be reduced.

The invention discloses a structure for consolidating and reinforcing a soft foundation through solar heat and an operation mode of the structure. The structure comprises a soft foundation drainage consolidation system, a solar heating system, a vacuum pressure system, a water filling pipe bag load increasing structure, a stacking structure and a foundation soil layer. The lower part of the soft foundation drainage consolidation system is inserted into the foundation soil layer, and the upper part of the soft foundation drainage consolidation system is arranged on the top surface of the foundation soil layer; the solar heating system and the vacuum pressure system are respectively connected with the soft foundation drainage consolidation system; the stacking structure and the water filling pipe bag load increasing structure are sequentially arranged on the upper portion of the soft foundation drainage consolidation system from bottom to top, the vacuum pressure system is arranged on the top face of the stacking structure, and the solar heating system is arranged on the top face of the foundation soil layer. The deep soft foundation is reinforced through combination of the drainage wall, a common drainage plate and solar thermal consolidation, the reinforcing effect is good, and the method is economical.

The invention relates to the technical field of optimal control over circulation of condensing steam turbines in the power generation process of large heat energy such as fire coal, fuel gas and nuclear energy, and discloses a backpressure switching optimal control technology applied to a condensing steam turbine. Comprising the following steps: a step of establishing a cold circulating water temperature control model: establishing a condenser cold circulating water temperature control model used for determining a relationship among a field environment temperature, a field wind speed, a unit load state and cold circulating water opening and closing time; and a backpressure adjustment model establishment step: controlling opening and closing of at least one vacuum pump inlet communication door according to the cold circulating water temperature control model and the blocking backpressure value of the steam turbine, so that the vacuum pressure between the high-pressure-side condenser and the low-pressure-side condenser is kept consistent. From implementation of technical measures of single and double backpressure switching and vacuum pump operation optimization, it is checked that the final-stage blade condition of the low-pressure cylinder of the steam turbine is good, and no obvious water erosion condition exists.

The invention relates to the technical field of civil engineering, in particular to an energy-saving and environment-friendly vacuum preloading foundation treatment method which comprises the steps that a foundation soil body is divided into a plurality of foundation units, and a plurality of vacuum pumps are installed according to initial operation parameters; pre-suction is conducted on the foundation, the vacuum state of any foundation unit is judged, the suction power or the predicted demand power of the corresponding vacuum pump is adjusted, and the under-membrane vacuum pressure of the foundation unit is measured for the second time; the consolidation state of the foundation unit is judged according to the pore water pressure, and the fluctuation of pore water pressure change is detected to determine the foundation consolidation stage; drawing an intra-membrane vacuum pressure change curve in the main consolidation stage, judging the change trend of the curve, and determining the stability of the intra-membrane vacuum pressure and the working state of the sealing membrane according to the fluctuation of the curve; and in the secondary consolidation stage, the ground subsidence height is measured to predict whether the vacuum preloading reaches the load required by the design or not. By evaluating the consolidation degree and stability of the foundation soil body, the efficiency and accuracy of vacuum preloading treatment are improved.

The invention relates to the technical field of oxygen production, in particular to a single-tower VPSA (vacuum pressure swing adsorption) skid-mounted oxygen production device applying a magnetic suspension fan and a fan pump, which comprises a first module and a second module, the first module comprises a magnetic suspension fan, an air cooler, an adsorption tower, an oxygen buffer tank I and a magnetic suspension fan pump; according to the invention, four storage cylinders for storing molecular sieves are arranged in the adsorption tower, and structures such as a locking mechanism, an upper electric telescopic cylinder and a lower electric telescopic cylinder are arranged, so that each storage cylinder can be automatically and independently taken out and poured out of the molecular sieves; and then a new molecular sieve is poured into the device, and the storage cylinder is sealed and installed back by the control equipment, so that the molecular sieve can be automatically replaced, a maintainer does not need to use a tool to disassemble a plurality of bolts and use a tool to replace the bolts, and the maintenance efficiency of the device is greatly improved.

The invention provides a weakly coupled resonator-based sensitization pressure sensor, which comprises a weakly coupled resonator and a heat conduction main body, the weakly coupled resonator is connected with the heat conduction main body, the heat conduction main body is arranged in a bending and circling manner, each main resonator of the weakly coupled resonator is made of different materials, and each main resonator is made of different materials. Each main resonator and the affiliated heat conduction main body are made of the same material, the pressure sensor organically combines the Pirani vacuum gauge and the weak coupling resonator, the sensitive stress of the weak coupling resonator comes from the thermal stress generated by the heat conduction main body, rigidity disturbance is provided for the weak coupling resonator, the measurement of vacuum pressure is realized, and the measurement precision is improved. According to the Pirani vacuum gauge, the measurement lower limit is expanded, the comprehensive performance is improved, on the premise that the test range of the Pirani vacuum gauge is not sacrificed, the same sensitive core can measure medium and low vacuum pressure, and the measuring range can be expanded to be close to the atmospheric pressure.

The present invention is directed to a 3D printed mold for creating three dimensional pulp products from a fibrous pulp slurry. Transverse filaments are integrated into an infill structure with an open-cell pattern. The transverse filaments form channels through the interior matrix of the mold. The open cell infill pattern and channels allow for the movement of vacuumed materials through the interior matrix of the 3D printed mold when vacuum pressure is applied. The product surface of the mold comprises an array of beads formed from the over-extrusion of melted material at the ends of the transverse filaments. The beaded array narrows the opening of the channels created by the transverse filaments, preventing the fibers from entering the matrix of the mold and clogging the flow of materials. This causes the fibers to aggregate on the product surface of the mold, forming the three dimensional pulp product.

The invention belongs to the field of ferrous metallurgy, and discloses an RH refining oxygen blowing decarburization method which comprises the following steps: dynamically adjusting the oxygen blowing flow and the oxygen blowing lance position according to the ratio of the content of carbon to the content of oxygen in RH incoming steel; the oxygen blowing amount is determined according to the initial values of the carbon and oxygen contents in the RH entering steel and the target values of the carbon and oxygen contents after decarburization is finished; a gradient lifting gas flow system is adopted in the RH decarburization process, the oxygen blowing opportunity of RH decarburization and the vacuum pressure in the oxygen blowing process are controlled, and when RH decarburization is finished, molten steel is controlled to be low in oxygen activity. According to different RH entering molten steel components, the oxygen blowing flow and the oxygen blowing lance position are dynamically adjusted, the gradient gas flow increasing system is adopted, the RH decarburization oxygen blowing opportunity, the oxygen blowing process vacuum pressure and decarburization ending molten steel oxygen activity control are combined, the oxygen utilization rate can be effectively increased, the decarburization period is shortened, and the decarburization efficiency is improved. The problem of molten steel recarburization caused by molten steel splashing due to too violent carbon-oxygen reaction is solved, RH efficient decarburization is achieved, the steel ladle top slag oxidability is reduced, and the molten steel cleanliness is improved.

A method of processing a substrate is disclosed that comprises: transferring the substrate into a processing chamber and positioning the substrate on an upper surface of a substrate holder in the processing chamber, wherein the substrate holder comprises one or more vacuum channels disposed at the upper surface and one or more electrodes disposed within the substrate holder proximate to the upper surface; while the substrate holder is within the processing chamber, clamping and flattening the substrate to the substrate holder by applying a vacuum to the one or more vacuum channels; while the substrate is clamped to the substrate holder via the one or more vacuum channels, applying a voltage to the one or more electrodes to further clamp the substrate to the substrate holder with an electrostatic force; pumping out the processing chamber to a vacuum pressure while continuing to clamp the substrate to the substrate with the electrostatic force; and while the substrate is clamped to the substrate holder by the electrostatic force, processing the substrate in the processing chamber under vacuum conditions.

The invention belongs to the technical field of testing devices, and discloses a maintenance testing device for a vacuum valve and a testing method thereof.The maintenance testing device comprises a first vacuum pressure gauge, a second vacuum pressure gauge, a vacuum cavity, a mass flow meter, a control box, a gas pressure adjusting and switching jig and a connector; the first vacuum pressure gauge and the second vacuum pressure gauge are both installed at the top of the vacuum cavity, the switching jig and the connector are installed at one end of the vacuum cavity, the bearing assembly is arranged below the switching jig and the connector, the supporting frame is arranged below the vacuum cavity, and the mass flow meter, the control box and the gas pressure adjusting device are installed in the supporting frame. Through the testing device, off-line valve detection can be carried out, pressure control testing and position control can be conveniently carried out on the valve, the testing efficiency of the valve is improved, the testing device further has the advantage of being small in occupied area, and the testing device can be matched with different jigs to operate valves of different specifications, so that the adaptability of the device is improved.

The prefabricated pier wet joint vacuum pressure injection construction method comprises the steps that S1, when a pier column is prefabricated, a mud jacking pipeline is pre-buried, one end of the mud jacking pipeline extends out of the bottom of the pier column, and the other end of the mud jacking pipeline extends out of the side face of the pier column to serve as a connecting end; s2, a pier column and a wet joint grouting formwork are installed; s3, the connecting end of the mud jacking pipeline is connected with a vacuumizing device; s4, self-compacting concrete is poured into the wet joint grouting formwork till the top of the wet joint grouting formwork is filled with the self-compacting concrete; s5, a vacuumizing device is started until the self-compacting concrete pumped out of the grouting pipeline is uniform and compact, and then the vacuumizing device is stopped; s6, after the wet joint concrete reaches certain strength, the vacuumizing device and the wet joint grouting formwork are disassembled; and S7, after the wet joint concrete reaches the design strength, the part, extending out of the pier column, of the mud jacking pipeline is cut off and beautified. According to the method, the compactness quality of the pier and abutment wet joint is improved, and rapid pouring connection of the prefabricated pier column and the bearing platform wet joint is achieved.

The invention relates to a multi-airflow alternating temperature calcining device for ultra-long nitride single crystal nanofibers. The multi-airflow alternating temperature calcining device comprises a reaction furnace; the mechanical vacuum pressure gauge and the exhaust port are arranged at the top of the reaction furnace; the reaction furnace chamber is arranged in the reaction furnace; the multi-reaction-zone graphite furnace body is arranged in the reaction furnace chamber and comprises a first low-temperature zone, a second high-temperature zone and a third low-temperature zone which are sequentially arranged from bottom to top and are not in contact with one another; the electromagnetic heating controller is arranged on the periphery of the multi-reaction-area graphite furnace body; the graphite boat is movably arranged in the multi-reaction-area graphite furnace body; the movable alumina crucible is arranged in the graphite boat; the graphite columns are arranged at the top and the bottom of the multi-reaction-zone graphite furnace body; the hydraulic cylinder is connected with the graphite column; and a control assembly. Compared with the prior art, the method has the advantages that the nitridation reaction process can be accurately controlled, the fiber quality and the crystal integrity can be improved, and independent and accurate temperature control can be realized.

The invention provides a vacuum pressure system, a parameter identification method and a parameter identification modeling method, which are applied to the technical field of semiconductor manufacturing, a mathematical model for describing the change of the pressure in a chamber along with time is constructed by applying the law of conservation of mass and an ideal gas state equation, the change of the pressure in the chamber can be accurately predicted, and the accuracy of the parameter identification is improved. And key system parameters can be determined in real time through a parameter identification process, so that the precision and the response speed of pressure control are remarkably improved, meanwhile, the adaptability and the stability of the system are enhanced, the thin film deposition process can be optimized, the quality and the uniformity of products are improved, and the production efficiency is improved.

The invention discloses a method for processing a pressure-resistant shell of an unmanned underwater vehicle, which relates to the technical field of underwater vehicles, and is technically characterized by comprising the following steps of: firstly, respectively forging a pipe material or a bar material, a cake material and a plate material by adopting titanium alloy, customizing raw materials, machining according to preset parameters, drilling, cleaning, and matching with radiographic inspection to complete processing of a shell, an end socket and a hoop; and the seal head also needs to be marked by laser. And in the assembling stage, an O-shaped sealing ring is arranged at the connecting part of the shell and the end socket for sealing, and a bulkhead of the cabin penetrating piece is fixed and assembled by using a hoop. Then, the vacuum degree change is monitored in a vacuum pressure maintaining mode to conduct air tightness detection, after qualification, a hydrostatic pressure test is adopted, step type pressure increasing is conducted according to preset pressure, the pressure is maintained to the specified time length, whether deformation and leakage occur or not is detected, finally, pressure-resistant shell machining is completed, the structural strength and sealing performance of the pressure-resistant shell are guaranteed, and the underwater use requirement is met.