82results about How to "Wide range of engineering applications" patented technology

The invention discloses a cutting-stirring friction welding composite processing device for a floating double-shaft-shoulder double-stirring needle and a manufacture method thereof, and particularly relates to a combined or composite processing device capable of simultaneously carrying out milling or cutting processing and stirring friction welding processing and a method thereof. The cutting-stirring friction welding composite processing device for the floating double-shaft-shoulder double-stirring needle integrates a cutting system or a milling system, a stirring friction welding system, a forced cooling system, a gas protection system, a temperature sensing system, a pressure induction system, a milling liquid supply system and a sensing-free system. The cutting-stirring friction welding composite processing device has functions of temperature control, gas protection, pressure detection, cooling liquid protection, milling head replacing and floating double-shaft-shoulder self-supporting stirring friction welding. The method for carrying out cutting-stirring friction welding composite processing on workpieces can meet strength requirements of mechanical processing of ferrous light metal materials, carbon steel materials and alloy steel materials. The cutting-stirring friction welding composite processing device for a floating double-shaft-shoulder double-stirring needle and the manufacture method of the cutting-stirring friction welding composite processing device reduce manufacture procedures, save processing cost, have the advantages of being high in efficiency, excellent in quality, high in stability and saving in energy, break through limitation of conventional machining technology, form a new method and a new thought for machinery processing, and have wide application prospects in industries of heating, air conditioners, ice manufacture, freshness keeping, medicine preparation, construction, aquatic products and foods.

The invention discloses a multi-target measurement and control communication antenna array optical fiber closed-loop calibration method, and aims to solve the problems of multiple antenna error calibration test parameters, inconsistency of receiving channels including antenna unit mutual coupling and large test quantity. The method provided by the technical scheme of the invention comprises the steps that a calibration signal generation unit generates receiving and transmitting calibration baseband signals based on a starting instruction; the receiving calibration baseband signal is subjectedto up-conversion to a radio frequency through the calibration frequency conversion unit, is transmitted to optical transmission equipment, is transmitted to the optical receiving / transmitting module of an antenna subarray through an optical fiber, is coupled to each receiving channel, and is transmitted to an amplitude-phase consistency measurement unit through the optical fiber after being processed, so that closed-loop calibration of receiving channels is realized; the transmitting calibration baseband signal is output to a receiving / transmitting calibration switch network through a switch network and a coupler and transmitted to rear-end optical transmission equipment; and the transmitting calibration baseband signal is obtained through down conversion and transmitted to the amplitude-phase consistency measurement unit, and closed-loop calibration of transmitting channels is achieved.

The invention discloses a test system for intelligently diagnosing faults of a high-integration digital signal processing system, and aims to solve the problem of low fault diagnosis capability of anexisting boundary scanning test system. According to the technical scheme, an intelligent test platform management unit operates control software, collects data of multichannel signals, generates a test sequence, allocates physical addresses to all modules, lists all the modules connected to a system backboard on a software interface, processes the multichannel data and diagnoses faults; the control software calls boundary scanning test software to generate a test vector for the tested module, applies the test vector to the chip core logic input end to form a circuit fault criterion, and sendsthe circuit fault criterion to the boundary scanning controller; the test vectors of different regions are loaded to a tested module to generate a fault injection vector, and the fault injection vector is transmitted to a fault injection controller; and the fault injection vector is loaded to the tested module to complete the fault diagnosis of the multichannel signal processing subrack platformmodule-level digital chip.

The invention discloses an islanding method for a power distribution network comprising distributed generation (DG) and considering an interconnection switch. The method comprises the steps of obtaining a new islanding model of a power distribution system comprising the DG based on a graph model of the power distribution system, and constructing a graph model G of the power distribution system in a power-losing area after a failure. The method provides theoretical criteria for constructing the islanding method of the power distribution network comprising the DG and considering the interconnection switch, which meets an engineering demand, a solving strategy for the islanding of the power distribution network comprising a looped network structure is proposed based on the algorithm, an engineering application scope of a islanding technique comprising the DG is expanded, the defect that the existing similar technique is not applicable to the islanding of the power distribution network comprising the interconnection switch is overcome, the application scope is wider, development requirements of an intelligent power grid structure are met, the solving algorithm of the islanding of the distribution network comprising the DG and considering the interconnection switch is low in time calculation complexity, and the practical engineering demand is satisfied.

The invention discloses a rough surface and target composite electromagnetic scattering simulation method based on the reciprocity principle, mainly solving problems of low simulation efficiency, poor simulation universality and high memory requirements in the prior art. The rough surface and target composite electromagnetic scattering simulation method based on the reciprocity principle is implemented by the steps of (1) generating the rough surface by the Monte Carlo method according to the power spectrum density function of the rough surface, (2) performing geometric modeling to the target according the size and shape requirements of the target, (3) adding the geometric model of the target into a rough surface model to generate a composite model, (4) calculating a direct scattered field by means of Kirchhoff approximation, (5) acquiring a coupling field between the rough surface and the target according to the reciprocity principle, (6) calculating the total scatted field of the composite model according the direct scatted field and the coupling field, and (7) acquiring monostatic radar scatted parameter of the composite model according the total scattered field and an incident field of the composite model. The rough surface and target composite electromagnetic scattering simulation method based on the reciprocity principle has the advantages of high simulation speed, simulation precision and universality, and can be applied to target detection in the background of the rough surface.

The invention discloses cutting-stirring friction-welding combined machining equipment and a manufacturing method thereof. The cutting-stirring friction-welding combined machining equipment integrates a milling system or a cutting system, a stirring friction-welding system, a forced cooling system, a gas protection system, a temperature sensing system, a pressure sensing system, a milling liquid supply system and a non-sensing system. The invention provides a united or combined machining device which can carry out milling or cutting and stirring friction-welding in parallel simultaneously and a method thereof. The cutting-stirring friction-welding combined machining equipment has the functions of temperature control, gas protection, pressure detection, cooling liquid production, milling head replacement and dual-shaft shoulder self-supporting. According to the manufacturing method of the cutting-stirring friction-welding combined machining equipment, the manufacturing processes are reduced and the machining cost is saved. The limitation of the conventional mechanical machining technology is broken through, and a new method and a new idea about the mechanical manufacturing and machining are formed. The cutting-stirring friction-welding combined machining equipment and the manufacturing method in the invention have wide engineering applications to the heating industry, the air conditioning industry, the ice making industry, the freshness retaining industry, the pharmacy industry, the construction industry, the aquatic product industry and the food industry.

The invention discloses a modeling method of rough surface microwave band bidirectional reflectance distribution function. The modeling method comprises the following steps of: generating a rough surface by a Monte Carlo method according to power spectral density function of rough surface; calculating unit radar cross section sigma 0 of the rough surface by a moment method; obtaining a bidirectional reflectance distribution function of the rough surface according to the relation between the rough surface scattering coefficient and the bidirectional reflectance distribution function; modeling a five-parameter empirical model according to the obtained bidirectional reflectance distribution function; selecting optimal standard according to the model parameters, optimizing the parameters of the five-parameter model to obtain empirical parameters; according to the empirical parameters obtained by optimization, modeling a rough surface bidirectional reflectance distribution function through the five-parameter empirical model. Compared with the prior art, the modeling method provided by the invention has the advantages of fast optimization speed, high modeling precision and strong universality, and can be used for study on features of rough surface microwave band bidirectional reflectance distribution function.

The invention relates to the technical field of solar energy, and especially relates to a solar photovoltaic module array data collection device and a data processing method thereof. The data collection device is internally provided with a data collection processing chip, a communication assembly connected with the data collection processing chip, a standard internet access and / or a USB interface connected with the data collection processing chip, a wired internet of things interface connected with the data collection processing chip, a current sensor connected with the data collection processing chip, and a power supply system connected with the data collection processing chip. The device has wired and wireless internet of things networking functions, and engineering application is wide. A 433 wireless communication module is used to acquire operating data of a solar photovoltaic module, a relay is not needed, and network structure is simplified into a two-layer structure, so complexity is low and networking is easy. The device is fast in data acquisition speed and good in real-time property. The device is excellent in wireless network performance, wide in coverage, and holds more number of inferior nodes.

The invention discloses a testing method of a single-pile multi-directional horizontal bearing force under combined loading effect. The method comprises the following steps: (1) determining the size of a test pile, soil distribution and thickness; (2) determining a vertical loading value and a loading level, and a horizontal loading value and a loading level; (3) paving soil in layers; (4) determining loading direction and quantity of horizontal loading; (5) mounting horizontal loading pile caps; (6) placing a horizontal loading system; (7) placing a vertical loading system; (8) mounting a data acquisition system; (9) determining multi-directional ultimate bearing capacity of the test pile for single time; (10) detaching the test device and recycling soil samples for testing; (11) determining horizontal bearing capacity characteristic values of a single pile under different vertical loading; (12) determining the horizontal ultimate bearing capacity of the single pile under different vertical loading; The method has a good effect, is convenient to operate and low in cost.

The invention belongs to the technical field of solar photovoltaic module detection, and specifically relates to a device and a method for monitoring data of embedded solar photovoltaic module data. The device comprises a data acquisition chip, a current sensor, a communication assembly, a temperature sensor, and a bluetooth interface. The data acquisition chip receives operational data of a solar photovoltaic module through the current sensor and the temperature sensor, and performs integral generating capacity calculation and hidden danger judgment according to the operational data. The operational data, the integral generating capacity, and hidden danger judgment results of the solar photovoltaic module are output through the communication assembly. The device uses an embedded microprocessor as the core, and combining with an internet of things technology, detects operating states of the photovoltaic module in real time, so as to realize intelligentized data acquisition and analysis, fault diagnosis, fault location, fault removing and alarm. The device and the method provide a simple solution for intelligentized and remote monitoring of a solar power station system.

The invention relates to an SCM (single-chip microcomputer)-based wide-range accurate measuring method for the real-time rotating speed of a motor. A designed speed measuring system comprises a speed-measuring generator or a linear Hall element, a signal amplification module, an A / D conversion module, an SCM processing module as well as a speed output and display module. The accurate and real-time rotating speed of the to-be-measured motor is directly estimated with a numerical algorithm running in the SCM processing module according to the sine induced electromotive force output by the speed-measuring generator or the linear Hall element, the problem that traditional simulation speed measuring circuits have low-rotating-speed feedback blind zones is mainly solved, and wide-range accurate measurement of the continuous and real-time rotating speed of the to-be-measured motor is realized.

The invention discloses a seven-hole probe airflow field wind speed and direction measuring method and device, and belongs to the field of airflow field testing, and the method comprises the steps: obtaining the instantaneous pressure values of seven holes outputted by a seven-hole probe; determining the subarea of the seven-hole probe corresponding to the incoming flow of the airflow field, and obtaining a pitch angle, an azimuth angle, and a total pressure coefficient and a static pressure coefficient related to the wind speed according to the instantaneous pressure value of each hole and the calibration coefficient corresponding to the subarea; obtaining a wind direction angle according to the pitch angle and the azimuth angle, and obtaining the wind speed of the airflow field accordingto the total pressure coefficient and static pressure coefficient related to wind speed. The seven-hole probe airflow field wind speed and direction measuring method and device can be used for efficiently, quickly and accurately measuring the wind speed and direction of the airflow field, standardizing the measurement process, improving the working efficiency and reducing uncertainty influence factors.

The invention belongs to the technical field of radar electromagnetic simulation, and discloses a rough surface and multi-target composite scattering simulation method based on iterative physical optics. The method comprises the following steps: inputting a rough surface power spectral density function and a roughness parameter, obtaining a rough surface geometric contour by the Monte Carlo method; using the simulation software FEKO to geometrically model the targets; adding the geometric models of the targets to the rough surface model to generate a composite model; using the physical opticsmethod to calculate the surface induced electromagnetic current directly scattered by the rough surface and each target; calculating the surface-induced electromagnetic current between the rough surface and the targets and between the targets according to the iterative strategy and Huygens principle; obtaining a far-field total scattering field of the composite model by the Huygens principle; andobtaining a two-station radar scattering coefficient of the composite model based on the total scattering field and the incident field of the composite model. The rough surface and multi-target composite scattering simulation method based on iterative physical optics has the advantages such as low memory requirement, high simulation efficiency and strong versatility of the simulation method.

The invention discloses an offshore wind turbine foundation structure automatic analysis system and method. The analysis system comprises an EXCEL-based system platform, a MATLAB program-based finiteelement parameter calculation module and an ANSYS program-based finite element structure analysis module. According to the system platform, office software EXCEL is adopted as an interface, programming is carried out through a VBA language of the EXCEL, and automatic calling of MATLAB programs and ANSYS programs and one-key batch processing automatic analysis of the basis of N fans are achieved. The operation method of the analysis system comprises a plurality of steps. The method is friendly in interface and convenient to operate, automatic modeling, automatic analysis and automatic specification checking of the finite element model can be completed, the one-button batch processing analysis function of multiple fan foundations is achieved, and the method is a powerful technical tool for offshore wind power large-scale development and has very wide engineering application and popularization value.

The invention belongs to the field of geotechnical engineering and relates to a prefabricated concrete square drainage pile for liquefaction resistance of foundation soil. According to the pile, vertical cavities are symmetrically formed in side surfaces of a prefabricated concrete square pile, porous aluminium alloy buckle plates are used for enclosing, and porous areas are covered with water filtering type geotextiles. Limitations that discrete material piles are insufficient in strength and rigid piles cannot drain water in the liquefied foundation soil reinforcing process are broken through. The pile comprises the prefabricated concrete square pile, the porous aluminium alloy buckle plates and the water filtering type geotextiles, all components can be produced in factories in batches, and the pile is simple in structure, high in pile body strength and good in drainage effect.

The invention relates to a testing device of single pile multidirectional horizontal bearing capacity under composite load. The testing device is characterized in that soil for simulating a site is placed in a model box, a test single pile is buried in the soil, a vertical loading system comprises standing columns, a crossbeam, a lever, a vertical loading device and vertical loading weights, one end of the lever is hinged to a rotary shaft between the two standing columns, the vertical loading device is mounted in the middle of the lever, the vertical loading device is located at the top of the test single pile, and the vertical loading weights are connected to the other end of the lever; a horizontal loading system comprises a horizontal loading pile cap, a fixed pulley, a steel wire rope and weights, the horizontal loading pile cap is mounted on the top surface of the test single pile and connected with one end of the steel wire rope, the steel wire rope penetrates the fixed pulley, the other end of the steel wire rope is connected with the horizontal loading weights, and the fixed pulley is mounted on the model box; a data collecting system comprises a displacement meter which is located on the horizontal loading pile cap and connected with a data collecting instruction. The testing device is good in effect, convenient to operate and low in cost.

The invention relates to a process for deep concentration of high-concentration brine. The process is realized based on a KFRO membrane device. Salt-containing wastewater is introduced from the waterinlet side of the KFRO membrane device, the wastewater flows through the exterior of a membrane bag, and water molecules pass through a membrane, enter the membrane bag, and is collected in a centraltube; concentrated brine is obtained on the concentrated water side of the KFRO membrane device, the high-concentration brine is introduced into the central tube of the KFRO membrane device from the direction opposite to the salt-containing water, flows through the membrane bag, and dilute brine flows out of the other end of the central tube of the KFRO membrane device; and the dilute brine is concentrated through a roll-type membrane device so as to obtain a concentrated liquid and effluent. The salt-containing wastewater and the high-concentration brine are operated in a countercurrent manner, and the source of the high-concentration brine can be the concentrated brine of the KFRO device or a concentrate of the roll-type membrane device, high pressure of 70 bar or above is not required,the high-concentration brine with a mass concentration of 5-10% can be further concentrated into 20%, and the operation energy consumption is far lower than a current common process, so that breakthrough of energy saving of brine concentration is achieved, and a zero emission technology affordable for users is provided.

A like-pole-type eight-pole radial electromagnetic suspension bearing comprises bearing seats, a stator and a rotor, wherein the rotor is located in an inner hole of the stator; the stator is composed of eight mutually independent electromagnets which are arranged at equal circular arc intervals and located on the same installation plane, and the like-polarity magnet poles of the eight electromagnets are arranged on the same cross section in the radial direction; eight electromagnet installation grooves are formed in the inner hole of the inner side of each bearing seat at equal circular arc intervals, and the electromagnets are in one-to-one correspondence with the electromagnet installation grooves; the two bearing seats are the first bearing seat and the second bearing seat, and the electromagnet installation grooves of the second bearing seat are in one-to-one correspondence with the electromagnet installation grooves of the first bearing seat to form electromagnet installation cavities; the electromagnets are located in the electromagnet installation cavities and are in interference fit with the electromagnet installation cavities; and the second bearing seat and the first bearing seat are fixed together. The like-pole-type eight-pole radial electromagnetic suspension bearing is smaller in size, easy to install and low in cost.

The invention provides a Doppler velocimeter speed correction method and an autonomous underwater vehicle navigation error correction method, and belongs to the technical field of unmanned autonomousunderwater vehicle navigation. The Doppler velocimeter speed correction method comprises the following steps: obtaining forward velocity and side velocity output by a Doppler velocimeter; calculatinginstallation error angle and velocity coefficient of the Doppler velocimeter according to the forward velocity and the side velocity; and carrying out correction computation on the forward velocity and side velocity output by the Doppler velocimeter based on the installation error angle and the velocity coefficient of the Doppler velocimeter to obtain corrected forward velocity and side velocity.The method has the advantages of low cost, easy operation and wide application range, and improves navigation error correction result reliability.

The invention relates to a pre-stress carbon-fiber deformed steel bar strengthening structure for refrigeration storage structure nodes and a method for producing the strengthening structure. Precast beams are arranged at precast columns to form refrigeration storage structure nodes. The strengthening structure is characterized in that pore passages are arranged in the precast columns and the precast beams, and precast metal sleeves and wedge-bond anchorages are arranged in the pore passages; pre-stress carbon-fiber deformed steel bars are arranged in the precast metal sleeves; high-damping silicone rubber concrete is poured in the precast metal sleeves; the wedge-bond anchorages are tubular metal cylinders and composed of anchor rings and wedges; the wedges clamp the precast metal sleeves and the inner pre-stress carbon-fiber deformed steel bars. The carbon-fiber deformed steel bars have the advantages of being light, high in strength, low-temperature and high-temperature resistant, anti-corrosion, anti-fatigue and the like; besides the high-damping silicone rubber concrete also has the advantages of being low-temperature resistant, so that assembly reinforced concrete storage structure nodes can be effectively strengthened, the structure wholeness can be enhanced, and the storage anti-seismic property can be improved. The method is suitable for being promoted and applied and provided with apparent social and economic benefits.

The invention discloses a standard six-degree-of-freedom parallel mechanism global optimization design method. With the load characteristic of a parallel mechanism considered, a standard Stewart parallel mechanism structure parameter design method meeting the requirement for local optimal dynamic isotropy is provided. On this basis, a global dynamic isotropic index is proposed based on the modal analysis theory, and specific parameter design of the parallel mechanism is achieved through optimal structure parameters with the index serving as an optimal object. By the adoption of the parallel mechanism designed with the method, complete decoupling and dynamic isotropy of a control center are achieved, and optimal performance of global work space is guaranteed. According to the standard six-degree-of-freedom parallel mechanism global optimization design method, the intrinsic coupling property of the parallel mechanism is eliminated through structural design, the performance of the parallel mechanism is improved, and therefore requirements for complicated control strategies of the parallel mechanism in order to improve control performance are reduced in industry.

The invention discloses an ultrahigh-strength magnesium alloy preparation method adopting a prestretching composite two-stage ageing technology. The method comprises the steps that a thermal deformation magnesium alloy is subjected to prestretching deformation under a certain temperature, and the deformation is controlled to be within 0.5-20%; and then appropriate two-stage ageing treatment is performed, that is, water quenching cooling is performed after heat preservation is performed for 0.25-20 h under the temperature of 80-130 DEG C, then a sample is heated to 140-250 DEG C and subjected to heat preservation for 5-200 h, and an ultrahigh-strength magnesium alloy can be obtained. By means of the method provided by the invention, good plasticity can still be guaranteed while the yield strength of the magnesium alloy is effectively improved, equipment requirements are simple, and operation is easy; and the magnesium alloy with the excellent comprehensive mechanical performance can beprepared, and the industrial application prospects are wide.

The invention provides a magnetic compass heading error correction method and an autonomous underwater vehicle navigation error correction method, belonging to the technical field of navigation of autonomous unmanned underwater vehicles. The magnetic compass heading error correction method comprises the following steps: acquiring the heading, provided by a magnetic compass, of the current moment; calculating according to the heading of the current moment so as to obtain magnetic compass semi-circular error generated by hard magnetic field interference; calculating according to the heading of the current moment so as to obtain magnetic compass quadrant error; acquiring magnetic compass circular error caused by soft magnetic field interference and installation error; calculating according to the magnetic compass circular error, the magnetic compass semi-circular error and the magnetic compass quadrant error so as to obtain magnetic compass error of the current moment; feeding the magnetic compass error of the current moment back to the heading, provided by the magnetic compass, of the current moment, and carrying out correction calculation on the magnetic compass heading to obtain corrected heading of the current moment. The magnetic compass heading error correction method and the autonomous underwater vehicle navigation error correction method have the advantages of being low in cost, easy to operate and wide in application scope, and improve the reliability of navigation error correction results.

The invention belongs to the field of anti-surge early-warning control of aero-engine air compressors, and is directly used for quickly determining a state of a surge occurred in the air compressor intests of whole engine and components of the aero-engine. A method for quickly determining the surge of the air compressor adopts a dynamic pressure probe, a dynamic pressure sensor, a dynamic data acquisition system, a processing and analysis program and a computer, wherein the dynamic pressure probe is installed at an outlet of an air compressor of an aero-engine, and is used for measuring dynamic pressure in a flow channel of the air compressor; a dynamic pressure signal is transmitted to the dynamic pressure sensor by means of the dynamic pressure probe; the dynamic pressure sensor sensesthe dynamic pressure signal, converts the dynamic pressure signal into an electric signal, and transmits the electric signal to the dynamic data acquisition system by means of a built-in converter; the dynamic data acquisition system processes the dynamic pressure signal into a frequency domain signal and inputs the frequency domain signal into the processing and analysis program; the processing and analysis program analyzes and compares sudden change situations of different band amplitude values, determines the occurrence of the surge; and the surge is reflected by means of the computer finally.

A heteropole type octupole radial electromagnetic suspension bearing comprises a bearing seat, a stator and a rotor; the rotor is located in an inner hole of the stator which is composed of eight mutually-independent electromagnets, the eight electromagnets are arranged at equal-arc intervals and located on the same installation plane, and magnetic poles of the eight electromagnets are arranged on the same cross section in the radial direction; eight electromagnet installation grooves are formed in an inner hole in the inner side of the bearing seat in an equal-arc mode, all electromagnets correspond to the electromagnet installation grooves in a one to one mode, and eight electromagnet installation grooves are formed in an inner hole of the inner side of a first bearing end cover in an equal-arc mode; the electromagnet installation grooves in the first bearing end cover correspond to the electromagnet installation grooves in the bearing seat in a one to one mode, and electromagnet installation cavities are formed; and the electromagnets are located in and assembled with the electromagnet installation cavities in an interference mode, and the first bearing end cover and the bearing seat are fixed together. According to the heteropole type octupole radial electromagnetic suspension bearing, the size is reduced, eddies are reduced, and machining is simplified.

The invention relates to a conductive slurry seal material and a preparation method and a paving technology thereof, and belongs to the field of road engineering. The conductive slurry seal material comprises the following components in percent by mass: 65-85% of aggregates, 3-8% of graphite, 0.5-2% of carbon fiber, 2.5-5% of emulsified asphalt, 2-6% of water, 0.5-1% of cement and 2-4% of epoxy resin A and B components, wherein the particle size of the used aggregate is 2.36-4.75mm. The paving thickness of the conductive slurry seal material during construction is 6-8mm. The conductive slurryseal material provided by the invention has high heating efficiency, is convenient to construct, is suitable for paving a conductive snow-melting and deicing structural layer of a newly-built road andan old road surface, and improves the driving safety on the road in winter.

The invention provides a full-domain magnetic compass course error correcting method and a navigation error correcting method for an autonomous underwater vehicle, and belongs to the technical field of navigation of an AUV. The full-domain magnetic compass course error correcting method includes the steps of: 1) acquiring the course, provided by a magnetic compass, at the present time and the magnetic declination of the AUV in a working domain; 2) according to the course at the present time, calculating semi-circumference error and quadrant error of the magnetic compass, which are generated via hard magnetic field interference; 3) acquiring the circumference error of the magnetic compass, which is caused by soft magnetic field interference and installation error; 4) according to the circumference error, the semi-circumference error and the quadrant error of the magnetic compass, calculating the error of the magnetic compass; and 5) feeding the error, at the present time, of the magnetic compass back to the course at the present time, and performing correction calculation to the course of the magnetic compass with the magnetic declination to acquire corrected course at the present time. The method has low cost, is easy to carry out and has wide adaptable range, and improves the reliability of a navigation error corrected result.

The invention discloses a tri-band bandpass microstrip filter with E-type resonators and stepped impedance resonators. E-type dual-band passband filters loaded to two open circuit branches are arranged in a back-to-back and symmetrical mode on a substrate; two multi-broken line feeder lines are coupled at one ends of the E-type dual-band passband filters; two stepped impedance dual-band passband resonators are embedded between the E-type dual-band passband filters and the multi-broken line feeder lines; and an input port I / P and an output port O / P are arranged at two ends of the two multi-broken line feeder lines. An embedded cross coupling structure with the back-to-back E-type resonators loaded to the open circuit branches and the SIR resonators loaded to short circuit branches is adopted, the passband selectivity is improved, and the size of the filter is reduced. the three-passband microstrip filter for an E-type resonator and a stepped impedance resonator can be applied to RFID, Wimax, and 5GWIFI bands, and has the advantages of simple design, compact structure, convenient processing and debugging, low cost, adjustable passband and good effects.

The invention provides a three-layer drainage cover for underwater local dry type low-pressure welding and a method for obtaining low pressure. The three-layer drainage cover for underwater local drytype low-pressure welding comprises the three-layer water drainage cover body, a welding system, a drainage system, an exhaust system, a cooling circulation system and a preheating system. By the adoption of the designed three-layer water drainage cover body, under the jointed action of multiple grades of pressurizing water pumps and pressurizing air pumps which are in full-automatic unified intelligent control, water in a welding local space and preheating space are forced to be discharged, forced air exhaust and forced smoke exhaust are conducted at the same time, and therefore a dry type normal pressure or low pressure area is formed in the welding local space; an electric arc stably combusts in the dry type normal pressure or low pressure area, the welding process is stable, the problems of weld joint metal hardening, high hydrogen content and the like are avoided, a connector or additive manufacturing product with the welding quality similar with the welding quality on the land oreven reaching high quality in a low pressure environment are formed. The three-layer drainage cover can be used for severe underwater environments of low visibility, large water flow velocity, industrial reaction solutions nuclear radiation and the like, can be used for butt welding, angle welding, groove welding, overlaying welding, spray welding, thermal spraying and additive manufacturing.

The invention provides a micro-pore anode used for a cluster plasma spray gun and a cluster plasma spraying method. The micro-pore anode comprises an anode front part, an anode middle part and an anode rear part, wherein the anode front part is designed with a powder conveying channel and a protective gas conveying channel; the inner diameter of an outlet of the micro-pore anode is limited withina range of 0.5-3 millimeters; micro-pore anode compression effect is utilized to obtain plasma micro jet flow which is focused in energy density and is small in divergence, and a local area on the surface of a to-be-sprayed workpiece is instantaneously molten while the integral temperature of the workpiece is prevented from rising, so that a coating and a basal body generate metallurgical bonding;the powder conveying channel which is in peripheral ring-shaped distribution is used for enabling powder to form tapered powder flow with a pre-designed included angle and small divergence, so that powder is heated and accelerated more uniformly in plasma micro jet flow to obtain a sprayed coating which is uniform in chemical component, is compact in micro structure, and defines metallurgical bonding.