65results about How to "Improve test conditions" patented technology

The invention relates to a small-sized environmental test chamber for pollutant release researches, which comprises a chamber body, an air generation system, a temperature-humidity control system, a sampling system and an air purifying device. By utilizing the small-sized environmental test chamber for simulating to approach real space, the temperature, the humidity and the air interchange ratio inside the chamber body can be controlled according to experimental conditions with low cost and simple operation. Meanwhile, the chamber body is provided with the purifying device, which can purify air samples at an air inlet and an air outlet so as to improve experimental conditions, be beneficial to acquiring real and reliable test data and avoid polluting indoor air.

A semi-physical simulation method of an aircraft electric system based on an AGENT modeling technique comprises a method for a virtual operating environment modeling method of intelligent control and test of an aircraft power system, a method for setup of a simulation model of a modern aircraft power system based on a multi-AGENT technique, a method for knowledge base modeling supporting decision assessment, a method for achievement of a semi-physical simulation platform, and a performance assessment method of the aircraft electric system. The method fully embodies a complete simulation model of distributed power control of a modern large aircraft, overcomes disadvantages that the aircraft power system is simulated mainly based on pure software at present and the effect of a load model on the aircraft power system cannot be well considered mostly; on the basis of setting up the model of the aircraft electric system based on the AGENT technique, with the adoption of a high-speed data collecting card, the method can conveniently form an effective semi-physical simulation verification platform together with a voltage regulator of an aircraft power generator and related detecting devices to verify reliability and safety of excitation control of the large aircraft electric system in real time.

The invention provides a preparation method for ultra-fine grain pure titanium through equal channel angular pressing. According to the invention, test conditions are improved on the basis of the prior art, a to-be-extruded sample is designed to be a copper-wrapped titanium rod, so frictional force generated during contact between the sample and a channel is reduced during extruding; extruding force is decreased to no more than 150 KN, so experimental operability is improved, and refining of industrial pure titanium can be finished at room temperature under small extruding force through equal channel angular pressing. At room temperature, the phenomena of restoring and recrystallization softening of crystal grains during refining hardly occur, so a substantial crystal grain refining effect is obtained and a high-strength industrial pure titanium block can be obtained through few times of extruding. According to results of testing of mechanical properties of the prepared ultra-fine grain pure titanium, the ultra-fine grain pure titanium has substantially improved comprehensive mechanical properties, block ultra-fine grain pure titanium can be used in practice, and the application scope of the ultra-fine grain pure titanium is broadened.

Provided is a distribution transformer integrated detection device comprising: a mobile device, and a detection module, an integrated wiring module, an integrated controller and a central controller arranged on the mobile device, the detection module accesses the integrated controller through the integrated wiring module to realize the automatic test of a distribution transformer, and the central controller realizes the analysis and storage of the test data. The distribution transformer integrated detection device can be conveniently detached and assembled and can be conveniently checked and maintained, performs integral control and management to complete the overall test report, performs the unified data management and diagnosis analysis, can comprehensively improve the efficiency, level, and quality of the electrical test, reduces the heavy carrying workload of the equipment during the test, improves the reliability of the transformer operation and technical management level to a large extent, can safely, flexibly, rapidly and effectively complete the relevant test projects, and realizes the intensive, digitalized, intelligent, and maneuvering transformation of the transformer equipment on-site test.

The invention discloses a near field simulator. Near-field spherical wave-front simulation is realized based on compact-field de-focusing control. Through continuous adjustment of the de-focused irradiation of an excitation source on a reflection plane, equivalent spherical wave sources at different distances are simulated continuously, with the purpose of compactly realizing a near-field electromagnetic environment with large distance coverage to conduct a near-field simulation test on a radio system. The near field simulator can work in a more controllable natural environment or electromagnetic environment, and is conducive to improving the test conditions of electromagnetic simulation debugging, reducing the test cost and improving the test efficiency. The near field simulator is better than an external field largely affected by natural weather. The near field simulator can work at the position of a wider-range equivalent spherical wave source, and is conducive to dynamically and variably configuring a near-field wave-front required for test and conducting a simulation test on a more vivid and changeable near-field electromagnetic environment required. The near field simulator is better than a near field of which the transmitting and receiving distance is controlled directly.

The invention provides an indoor simulation testing method for a communication distance of a radio station. A system according to the invention comprises a radio station I, a radio station II, an adjustable attenuator and a wireless channel simulator. The radio station I transmits a testing signal to the adjustable attenuator. After attenuation processing is performed on the testing signal through adjusting the attenuation value of the adjustable attenuator, the processed testing signal is transmitted to the wireless channel simulator. Through loading a corresponding model, the wireless channel simulator simulates a fading characteristic, a time delay characteristic and a frequency shifting characteristic of a radio wave in different propagation environment conditions. After the testing signal is processed, the processed testing signal is transmitted to the radio station II. The indoor simulation testing method has outstanding advantages of high flexibility in setting testing conditions (such as testing field landform, metrological environment and ionosphere change), high ergodicity in setting the testing conditions, high repeatability in setting the testing condition, high testing result precision, etc.

The invention discloses a load test board with a sail stress simulation function. Mechanical hardware of the load test board includes a base, an oil tank, a motor, a low-speed large-torque motor, a pinion, a main gear, a gear shaft, a bearing and bearing seat set, a reducer, a coupler, a magnetic powder brake, an encoder and a torque sensor. According to the arrangement, the rotating angle of main gear simulates that of the sail; the magnetic powder brake is used with the reducer to simulate resistance applied onto ship during sailing. A hydraulic system of the load test board comprises the oil tank, the motor, a gear pump, a speed-regulating reversing valve, the motor, a one-way valve, a relief valve, a pressure sensor, a flow sensor and the main gear. The main gear is used for driving a sail rotation simulating mechanism. The load test board has the advantages that under varied wind field conditions, the stress applied onto the sail can be simulated in the real-time manner, structure is simple, operation is reliable, functions are complete, stability is high, and response speed is high.

The invention relates to a tension force transducer which is mainly used for testing tension mechanical properties of materials, and comprises a force measurement part, a mounting part for mounting a test piece, and a strain gage pasted on the surface of the force measurement part, wherein one end of the mounting part is connected with the force measurement part; the force measurement part and the mounting part are in an integral structure; a center line of the force measurement part in the thickness direction and a center line of the mounting part in the thickness direction are in the same straight line; the mounting part is provided with a groove for placing the test piece; the groove and the strain gage are located on the same side; a notch is formed at the other end of the mounting part and located in an extension line in the length direction of the force measurement part; the notch is communicated with the groove; the width of the notch is less than that of the groove; and the test piece extends out of the mounting part through the notch. The tension force transducer further comprises a cover plate arranged above the groove, wherein the cover plate is clung to and fixedly connected with the mounting part by a plurality of fasteners. The tension force transducer is small in size, simple in structure, low in cost and good in test effect.

The invention discloses a vortex-induced vibration testing system suitable for multi-oscillator coupled vibration research, and relates to the field of fluid mechanics and experimental facilities. The vortex-induced vibration testing system is formed by three parts of a fixed supporting module, a slidable supporting module and a sliding system; the slidable support module can freely slide on the fixed supporting module, and meanwhile the sliding system can do vertical linear reciprocating motion on the slidable supporting module through a tension spring. The vortex-induced vibration testing system is not only suitable for a single-oscillator vortex-induced vibration test, but also suitable for a two / more-oscillator vortex-induced vibration test under the condition of various arrays. Meanwhile, the system can achieve various configuration forms such as series connection, parallel connection, inclined configuration and series-parallel coupling configuration among multiple oscillators, expands the research range of vortex-induced vibration, and supplies good testing conditions to multi-oscillator coupled wake galloping research.

The invention discloses a method and device for high-throughput characterization of heat and a structure in the process of crystal material melting and solidification. The method comprises characterizing the change of heat in the process of crystal melting and solidification in real time through a differential scanning calorimetry method, simultaneously, analyzing the structural information of theprocess in real time through X-ray diffraction, and in the crystal growth process after nucleation, observing the micro-structure evolution in real time through X-ray imaging. In one experiment, heatinformation in the crystal material melting-solidification process, melt structure change information along with temperatures before solidification and solidification micro-structure evolution information such as a solid / liquid interface advancing speed and dendritic crystal morphology when solidification are obtained. The device greatly shortens the research cycle of the crystal material melting-solidification process, realizes high-throughput characterization test analysis of the process heat and structure information in the same experiment and is used for the regulation and control of crystal material properties.

The invention discloses a multi-feed-source array near-field simulator based on a compact field system. The multi-feed-source array near-field simulator can realize high-quality near-field spherical wavefront simulation based on compact field offset focus control and a feed source array excitation source technology. The offset-focus irradiation of the reflecting surface is realized by adjusting the position of an excitation source; the near field of the biased reflecting surface is equivalent to the near field wavefront of the spherical wave source at different positions; and when the positionof the excitation source is continuously changed, the position of the equivalent spherical wave source is continuously changed, the position of the equivalent source of the near-field spherical wavefront is continuously adjustable in a large range, and an amplification relation exists between the adjustment amount and the expected control amount, that is, near-field simulation in a large-distancerange is compactly realized. The excitation source is in the form of a feed source array, and the high-quality quasi-spherical wavefront can be synthesized by weighting the amplitude and phase of thefeed source array unit, so that the problem of large wavefront distortion of spherical waves generated by single feed source excitation is solved. According to the invention, a high-quality sphericalwavefront equivalent near-field electromagnetic environment adjustable within a large distance range is realized by using a compact field.

The invention provides a human serum CCL2 enzyme-linked immunosorbent assay kit as well as preparation and use methods thereof. The human serum CCL2 enzyme-linked immunosorbent assay kit comprises an enzyme-labeled reaction plate, a CCL2 standard product, biotin-labeled antihuman CCL2 antibodies and streptavidin-labeled horse radish peroxidase, wherein the enzyme-labeled reaction plate is coated with mouse-anti-human CCL2 monoclonal antibodies. The preparation method of the human serum CCL2 enzyme-linked immunosorbent assay kit comprises the steps of preparing the enzyme-labeled reaction plate, the CCL2 standard product, the biotin-labeled antihuman CCL2 antibodies and streptavidin-labeled horse radish peroxidase, wherein the enzyme-labeled reaction plate is coated with the mouse-anti-human CCL2 monoclonal antibodies. The use method of the human serum CCL2 enzyme-linked immunosorbent assay kit comprises the steps of adding samples, biotinylation antibodies and horse radish peroxidase, and carrying out color developing and terminating.

The invention discloses a radar directional diagram measurement method based on a parabolic antenna, and the method comprises the steps: taking an auxiliary antenna for measurement as a transmitting antenna, and taking a measured parabolic antenna as a receiving antenna; adjusting a feed source of the parabolic antenna to be at a positive focus position through an auxiliary adjustment device, andlocking the relative position; rotating the parabolic antenna, recording the azimuth angle of the parabolic antenna as a measurement starting angle when the deviation of the pointer of the frequency-selective amplifier is the maximum; continuing to adjust the antenna till the frequency-selective amplifier points to 0, and determining a measurement end angle; reading the indicated values of the frequency-selective amplifier at the intervals of delta(theta) from the measurement start angle to the measurement end angle, taking the direction angle of the parabolic antenna and the indicated valuesof the frequency-selective amplifier as the parameters of all points, drawing the position of each point in the rectangular coordinate system and the polar coordinate system, and connecting all pointsinto a curve to obtain a corresponding horizontal directional diagram of the parabolic antenna. The method is simple in measurement process, is reliable in measurement result, and is especially suitable for the demonstrative testing.

The invention belongs to the technical field of marine corrosion protection, and particularly relates to a preparation method of a magnetic particle-enriched anticorrosion-antifouling integrated self-repairing microcapsule. The preparation method comprises the following steps: with materials such as epoxy resin, polyurethane, tung oil and the like as self-repairing agents, adding dispersing agents such as an emulsifier and the like, and uniformly dispersing a core material into an aqueous solution to form a stable oil-in-water microemulsion; then subjecting urea and formaldehyde to a condensation polymerization reaction to coat micro-droplets so as to prepare a microcapsule which is uniform in particle size and has core-shell structure; allowing magnetic nanospheres to be generated on the surface of the wall of the microcapsule in situ so as to synthesize microcapsule particles with self-repairing and anticorrosion effects; and compounding an emulsifier with the surfaces of the microcapsule and enabling the magnetic nanospheres to be selectively deposited so as to achieve the purpose of uniformity and controllability. The preparation method is simple, test conditions are convenient, large-scale production can be achieved, the service life cycle of an organic coating can be effectively prolonged, a release rate and repairing effect can be improved, the anticorrosion and antifouling performance of the coating can be enhanced, and long-period corrosion prevention of the organic coating can be achieved.

The invention relates to a rotor speed monitoring processor, comprising a main control module, a power module, a base component and a cover component. The processor is characterized in that the main control module comprises a speed interface circuit, a discrete output drive circuit, a frequency-voltage conversion circuit, a DC output circuit, a speed comparison circuit, and a CPLD control circuit.The CPLD control circuit is respectively connected with the speed interface circuit, the discrete output drive circuit, the frequency-voltage conversion circuit, and the speed comparison circuit, andthe frequency-voltage conversion circuit is respectively connected with the DC output circuit and the speed comparison circuit. The rotor speed monitoring processor introduces the helicopter rotor speed magnetic sensor signal and the onboard power supply to the main control module and the power supply module respectively through the base component. The main control module collects the frequency signal of the speed magnetic sensor, and real-time converts all the collected frequency signals into analog signals and discrete signals for collection by on-board back-end equipment.

The invention discloses a solid-liquid phase change-based ocean temperature difference energy conversion process simulation test device and method. The device comprises a heat exchange unit, a hydraulic unit, a transmission unit, an electricity storage unit and a data collector; the heat exchange unit comprises a cold-heat exchanger, a constant-temperature water tank, a temperature sensor and a heat exchanger; the hydraulic unit comprises a one-way valve, an energy accumulator, a pressure sensor, an electromagnetic valve, an adjustable throttle valve, a hydraulic motor, a flow sensor, a pressure regulating valve, a liquid level sensor, an oil tank and hydraulic pipes, wherein the hydraulic pipes are located among hydraulic devices; the transmission unit comprises a coupler, a speed sensor,a torque sensor, a speed reducer and a generator; the electricity storage unit comprises a rectifier bridge module, a storage battery, a current sensor and a voltage sensor. According to the device,indoor multivariable simulation testing is carried out on an ocean temperature difference energy conversion process based on a solid-liquid phase change mechanism. The device has the advantages of being accurate in measurement data, capable of continuously collecting data, high in automation degree, high in universality and the like.

The invention provides a rolling bearing high speed vibration measurement device, relating to a vibration measurement device. Existing bearing detection is low-speed detection, however a bearing actual working state is usually in a high speed operation, the grasp of bearing actual performance can not be satisfied by an existing low-speed detection method, and an actual working need can not be satisfied by the detection data. The rolling bearing high speed vibration measurement device comprises a test stand, an axial loading device, a sensor positioning device, a sensor positioning device, a driving spindle, and a master base. The master base is horizontally arranged. The test stand is arranged on the base. The sensor positioning device is arranged on the test stand. One side of the sensor positioning device is provided with an axial loading device. The other side of the sensor positioning device is provided with a driving spindle. A test bearing sleeves the driving spindle and tightly pushes the driving spindle through the axial loading device, and the detection head of the sensor assembly is close to the outer ring of the test bearing. The rolling bearing high speed vibration measurement device is used in bearing detection.

The invention provides a content measurement method for a trace amount of alcohol or ketone substance in transformer insulation oil. The content measurement method comprises the steps of adding a standard addition liquid of a to-be-detected alcohol and / or ketone substance into to-be-measured transformer insulation oil by a standard addition method, and preparing a series of standard samples with different addition concentrations; performing separation detection by a headspace sampling method and by a gas chromatography-FID detection method or a gas chromatography-mass spectrum combination method, and acquiring chromatogram peak area of a corresponding to-be-measured alcohol and / or ketone substance in the samples; and building a standard curve according to the chromatogram peak area and theaddition concentration of the standard samples, performing fitting to obtain a linear equation, and calculating the content of the to-be-measured alcohol and / or ketone substance in a substrate solution according to the linear equation. By the measurement method, test of various types of alcohol or ketone substances can be achieved by sampling in one time, the content measurement method is good inrepeatability and stability, the measurement accuracy is improved, and the measurement range is expanded.

The invention discloses an aircraft movable airfoil adjustment detection system and method. The system includes a signal conditioning box, a board card plug-in box, an integrated control computer, a programmable power supply, a displayer and a matched cable. The signal conditioning box is used for fault positioning and metering of the aircraft movable airfoil adjustment detection system, the matched cable is connected with the signal conditioning box and actuators and control plane position sensors on the airfoils and emages, the board card plug-in box provides a required excited signal to drive the actuators to do concertina movement after a work command is adjusted, and the integrated control computer sends an operating personnel command through a human-computer interaction interface tocontrol the movable airfoils to move and feeds back the motion states of the airfoils to a software interface, so that adjustment and detection of secondary airfoils, spoilers, secondary airfoil position sensors, an elevator, a rudder and an elevator position sensor are completed.

The invention relates to a missile simulation launching device. The missile simulation launching device comprises a test platform, a guide rail, a simulation missile, a missile mounting rack, an air pressure thrust system, an air pressure resistance system and an air compressor, wherein the test platform is a cubic structure frame; the guide rail is fixedly mounted on the test platform; the upperpart of the missile mounting rack is fixedly connected with the simulation missile, and the lower part of the missile mounting rack is slidably connected with the guide rail; the air pressure thrust system is arranged at the rear end of the simulation missile; the air pressure resistance system is arranged at the front end of the simulation missile; the air pressure thrust system and the air pressure resistance system are both connected with an air compressor air channel; and the simulation missile and the missile mounting rack do reciprocating motion between the air pressure thrust system andthe air pressure resistance system. The pressure of a power source of air is adjusted through the air pressure thrust system, the launching thrust of the simulation missile is specifically and accurately controlled in data, and the operation is more accurate than ejection; and the thrust action time can be controlled, and thus the requirement for simulating a real continuous high-overload environment is met.

The invention provides a content measurement method for a trace amount of aldehydes or ketone substance in transformer insulation oil. The content measurement method comprises the steps of preparing amethanol solution containing a to-be-measured aldehydes and / or ketone substance as a standard addition liquid; adding the standard addition liquid into to-be-measured transformer insulation oil, andpreparing a series of samples; performing separation detection by a headspace sampling method and by a gas chromatography-FID or gas chromatography-mass spectrum combination method, and acquiring chromatogram peak area of a corresponding to-be-measured substance in the samples; and building a standard curve according to the chromatogram peak area and the addition concentration of the samples, performing fitting to obtain a linear equation, and calculating the content of the to-be-measured substance in the to-be-measured insulation oil according to the linear equation. By the measurement method, test of various types of aldehydes or ketone substances can be achieved by sampling in one time, quantitative and qualitative measurement of the aldehydes or ketone substances in the insulation oilis achieved, the content measurement method is good in repeatability and stability, and new judgment standard and idea is provided for improvement of aging estimation of a cellulose insulation material in a transformer.

Disclosed in the invention is a simulated ship-bone aircraft take-off and landing training platform. Key points of the technical scheme are as follows: the simulated training platform comprises a main simulated platform body, a take-off protection platform and a commanding tower; the main simulated platform body is mainly responsible for simulating a navigation state of an aircraft carrier in the sea; the take-off protection platform is responsible for protecting an aircraft to enable the aircraft to glide continuously at the take-off protection platform for emergency under the circumstances that the aircraft fails to take off without lifting off; and the commanding tower is used for operating and controlling the state parameter of the simulated platform as well as aircraft take-off and landing information commanding. According to the invention, a plurality of high-power motors are used for driving a driving device and thus the flight deck is driven to make forth-and-back, left-and-right, and up-and-down oscillation; and a track is laid and thus the simulated platform can moves forward on land at the set speed, so that the relatively actual navigation state of the aircraft carrier in the sea can be simulated. And a good testing condition is provided for take-off and landing of the ship-bone aircraft.

A fluorometric determination method for flavoxate hydrochloride comprises the steps that a sample solution of a flavoxate hydrochloride tablet is prepared, an FX standard curve with a series of concentration is drawn, and sample concentration is measured; when the sample concentration is measured, the diluted sample solution is heated in a boiling water bath under the strong alkali condition, fluorescence spectrum scanning is conducted on the cooled sample solution by using a fluorescence spectrophotometer, the fluorescence intensity is measured when lambda<ex> / lambda<em> = 302 / 410 nm, and the concentration of FX in the sample solution is calculated. Accordingly, the fluorometric determination method is used for measuring the FX content of the flavoxate hydrochloride tablet, the sensitivity degree is high, the analysis speed is high, the testing conditions are simple and convenient, the environment-friendly effect is achieved, and the needed sample dosage is greatly reduced.

The invention discloses a motor hydrostatic test tank used for a deep well submersible electric pump, and relates to the pressure container technical field. The motor hydrostatic test tank comprises atop cover, which is provided with a cable sealing connector. The cable sealing connector comprises a lens pad, a stud bolt, a blind plate, a conical pad, a conical base and a supporting plate. The middle part of the top cover is provided with a first through hole for passing through a cable of an experimental motor, and the lens pad is arranged between the first through hole and a conical sealingsurface on the blind plate. The upper end of the conical base is fixedly connected with the lower end of the blind plate in a sealed manner, and the middle part of the conical base is provided with the conical pad, and in addition, the conical pad is attached to the conical base through the conical surface, and the conical pad is used to form sealed cooperation between the outer surface of the cable and the blind plate, and the lower part of the conical pad is provided with the supporting plate. The invention is advantageous in that the working environment (high pressure) of the motor for coal mine or other deep well operations is simulated so as to test the performance of the motor, and the sealing performance of the conical pad and the outer surface of the cable are improved.

The invention discloses a power monitoring and energy saving system which comprises a discharging circuit module and a grid-connected inverting circuit module, wherein the grid-connected inverting circuit module comprises a high-performance DSP (Digital Signal Processing) main board; the input end of the discharging circuit module is connected into the input end of the grid-connected inverting circuit module, and the output end of the grid-connected inverting circuit module is connected into a power grid; the discharging circuit module comprises an LC filtering circuit consisting an inductor L1 and a capacitor C1 and a power pipe Q1; and the power pipe Q1 and an inverting circuit are both controlled by the high-performance DSP main board. The LC filtering circuit is adopted in the discharging module and can obtain constant current and voltage; and when in use, the system can run in a constant current, resistance and power state just by setting the power supply ageing condition of the system and the current, resistance and power of a storage battery in a charging and discharging test, calculating and analyzing a set parameter by the high-performance DSP main board and outputting a corresponding parameter value for controlling conduction or interruption of the power pipe.

The present invention provides a motor load test tooling, comprising a tooling base, wherein the tooling base is provided with a test motor mount and a connection post that is arranged vertically; a test motor is placed on the test motor mount; the test motor is provided with a test motor output shaft that is arranged vertically upwards; a movement assembly is provided on the connection post; themovement assembly is provided with a test motor driven shaft bearing mount and a brake assembly; the test motor driven shaft bearing mount is connected to a test motor driven shaft through a bearing;the brake assembly is connected to the test motor driven shaft; the bottom of the test motor driven shaft is provided with an output shaft connection device; and the top of the test motor output shaftis inserted into the output shaft connection device. The motor load test tooling has the advantages of a reasonable structure, a flexible adjustment process in which the operation of the test motor can be adjusted from no-load to different load conditions through the braking principle by controlling the tightness of a brake, and effective optimization of test conditions.

The invention proposes a motor load testing tool, which includes a tool base, a test motor mounting seat and a vertically arranged connecting column are provided on the tool base, a test motor is placed on the test motor mounting seat, and a vertically upwardly arranged test motor is provided on the test motor The output shaft and the connecting column are provided with a moving assembly, and the moving assembly is provided with a test motor driven shaft bearing mounting seat and a brake assembly. The test motor driven shaft bearing mounting seat is connected to the test motor driven shaft, the brake assembly and the test motor through a bearing. The driven shaft of the motor is connected, the bottom of the driven shaft of the test motor is provided with an output shaft connection device, and the top of the output shaft of the test motor is inserted into the output shaft connection device. The motor load test tooling of the present invention has a reasonable structure, can adjust the test motor from no-load to different load conditions by controlling the tightness of the brake through the brake principle, and the adjustment process is flexible and effectively optimizes the test work. advantage of the situation.

The present invention relates to an engine parameter collection box. The engine parameter collection box comprises a main control module, a power module and a plug board part, the main control moduleis connected with the power module, the power block is connected with the plug board part, and the main control module can achieve centralized collection of multiple types of signals of an engine andcan convert the signals to RS422 bus signals for output. The engine parameter collection box can effectively reduce the errors caused by long-distance concentration of source end signals on the engineand can ensure the real and effective signals.