12 results about "Background current" patented technology

The application discloses a full-range error live calibration device and method for a low-voltage current transformer, comprising: a current control unit for outputting full-range calibration current control signals of each frequency; a hetero-frequency calibration current source for outputting full-range hetero-frequency current signals based on the current control signals and injecting the signals into the measured current transformer and a standard current transformer; an open current sensor for measuring a background current signal in real time; a signal decoupling unit for acquiring a mixed-frequency error voltage signal, eliminating a voltage component generated by the background current signal in the mixed-frequency error voltage signal, and acquiring a hetero-frequency error voltage signal; an error measurement unit for calculating ratio error and phase error of the measured current transformer based on the hetero-frequency standard signal and the hetero-frequency error voltage signal; and a data processing unit for determining calibration error under a power frequency frequency mapping based on the ratio error and the phase error under each hetero-frequency frequency.

This invention relates to the field of radioactive separation technology, and discloses an automated solution preparation and delivery control method and system for At-211 separation, comprising: Step 1, determining the column bed volume, setting the minimum operating volume particle size, and determining the pump running time; Step 2, solidifying the reagent and matching it with the valve inlet, obtaining the background current and determining the low threshold current, high threshold current, tail threshold current, and volume confirmation rules for the buffer solution; Step 3, generating the loading solution; Step 4, delivering the low-acid washing column solution, buffer solution, and preset equilibration solution to obtain the separation column; Step 5, loading the sample and comparing the output current of the ionization chamber with the low threshold current and high threshold current to determine the three states; Step 6, switching the collection valve to the product bottle and cutting off the organic elution solvent; Step 7, controlling the collection valve and determining the actual product volume. This invention achieves automated and quantitative control of solution preparation, delivery, elution, and collection during the At-211 separation process.

The present disclosure provides an apparatus, system, and method that can optimize in vivo electrochemical measurements of a target molecule, such as glucose. The disclosed embodiments can include an interference zapping layer to which a potential can be applied to prevent or minimize the arrival of various interfering molecules at the working electrode. Embodiments of the present disclosure can additionally or alternatively include a sensor that includes a plurality of working electrodes. A sensor having a plurality of working electrodes can measure a background current during sensing to determine the background current, current due to electrochemically interfering substances, and current due to the target molecule, specific to each electrode. The sensor can also execute a measurement mode in which a plurality of currents are measured over a range of interference zapping layer potentials and a range of working electrode potentials.

This invention discloses a method for reliable communication using pilot square waves, relating to the field of two-bus communication technology for electronic detonators. The method includes the following steps: S1, Line Status Awareness: Before entering uplink communication, a pilot square wave is sent. Bus current sampling data is acquired within the sampling window corresponding to the pilot wave, forming a background reference feature quantity. Based on the background reference feature quantity, the line status is classified to obtain the line status category for subsequent decision-making. The line status category and the background reference feature quantity are cached as real-time modeling results. S2, Command Sending and Sampling: A downlink command containing a carrier square wave is sent. This invention utilizes pilot square waves to perform real-time modeling of line distortion and background current, and extracts key current features based on a dynamic sampling window to construct an adaptive threshold decision, thereby achieving reliable identification of uplink feedback current in complex line environments.

A neurostimulator is implantable into a body of a subject to treat an overactive bladder condition. The neurostimulator includes a pulse generator, circuitry, a lead, and a connector secured to the lead. The circuitry is disposed within the pulse generator and connected to a battery. The circuitry is configured to generate a stimulation signal with a duty cycle of between 0.1% and 2.5% and a total average current drain from the battery of between 0.1 μA and 5μA, the total average current drain including a background current, plus a stimulation current weighted by the duty cycle. The lead has an electrode assembly configured to direct the generated stimulation signal to tissue of the subject. The connector is adapted to allow the pulse generator to be detachable from and attachable to the lead.

The invention relates to the technical field of radioactive separation, and discloses an automatic liquid preparation and conveying control method and system for At-211 separation.The method comprises the steps that 1, the column bed volume is taken, the minimum action volume granularity is set, and the pump operation duration is determined; step 2, enabling the curing reagent to correspond to a valve inlet, and obtaining background current, low-threshold current, high-threshold current, tail-threshold current and a volume confirmation rule by the buffer solution; step 3, generating a loading solution; 4, conveying a low-acid pickling column solution, a buffer solution and a preset equilibrium solution to obtain a separation column; 5, sampling and taking the output current of the ionization chamber to be in three states compared with the low-threshold current and the high-threshold current; 6, switching a collecting valve to a product bottle, and cutting an organic elution solvent; and 7, controlling a collecting valve and determining the actual product volume. According to the invention, automatic and quantitative control of liquid preparation, conveying, elution and collection in the At-211 separation process is realized.

The present invention provides an active noise reduction method based on analog circuit design, including a background current analysis module, an analog sampling feedback control unit, a power amplification unit, G1, G2, a signal conditioning circuit, a G3 current booster and an analog active noise reduction method equivalent circuit. In the power supply excitation stage, the background current analysis module inversely calculates the primary busbar current of the CTX to be calibrated through the secondary signal of CT0. G1 receives the CTX detection signal and forms a compensation current control signal. The compensation current control signal is transmitted to G2. The output end of the G2 circuit is signal-connected to the G3 current booster. The output end of the G3 current booster releases the output current and forms a closed loop. Moreover, G1 and the CTX detection signal are respectively inside the analog sampling feedback control unit, and G2 and the G3 current booster are respectively inside the power amplification unit.

The utility model discloses an X-ray image intensifier, which belongs to the technical field of X-ray imaging and is sequentially provided with an incidence window, a scintillator, a photoelectric cathode, an anti-ion feedback film, a micro-channel plate and a fluorescent screen along the incidence direction of X-rays. The incident window, the scintillator and the photoelectric cathode are tightly attached; the photoelectric cathode, the anti-ion feedback film, the micro-channel plate and the fluorescent screen are arranged at intervals; a plurality of one-way channels which form included angles with the horizontal plane in the axial direction are distributed on the micro-channel plate dot matrix; the photoelectric cathode, the anti-ion feedback film, the micro-channel plate and the fluorescent screen are arranged at intervals, so that the influence of ion feedback on the photoelectric cathode and the micro-channel plate can be effectively reduced, and the effects of reducing noise and improving the sensitivity and signal quality of the detector are achieved; meanwhile, the one-way channels in the micro-channel plate are obliquely arranged, so that the collision probability of electrons can be increased to strengthen the electron multiplication effect, ion feedback can be further reduced, the multiplication stability is improved, and noise and background current are reduced.

The invention provides a method and a device for calculating background current of a dynamic rod carving test of a pressurized water reactor, and the method comprises the following steps: during the dynamic rod carving test, after a first control rod group is carved, immediately lifting the first control rod group to the top of the reactor; performing exponential fitting on the power range current and time 100s + / -20s before the Doppler heating point is reached so as to solve and obtain omega and a; performing linear fitting on the power range current and time t when the first control rod group is lifted to the reactor top power range current which just starts to rise for 100s + / -20s so as to solve Ib, 1 and b; and S5, substituting Ib, 0 = Ib, 1 into a formula II for exponential fitting, repeating the step S4 and the step S5, and when Ib, 0 and Ib, 1 are the same, confirming that Ib, 1 at the moment is the real background current. According to the method, the background current is obtained through iterative solution by using the two sections of data close to the Doppler heating point interval and the background current interval, so that the technical problem that the economy of a nuclear power unit is affected due to the fact that an existing background current measurement method needs waiting time and occupies an overhaul main line is solved.

The invention discloses a gold nanowire micro-nano probe as well as a preparation method and application thereof, and belongs to the technical field of nano electrochemical sensors and biomolecule detection. The gold nanowire micro-nano probe comprises a glass capillary substrate, a gold nanowire layer and an insulation sealing layer, the glass capillary base body is provided with a tip area, the tail end of the tip area is provided with an electroactive area, the surface of the tip area is wrapped with a gold nanowire layer, and the surface of the gold nanowire layer is wrapped with an insulating sealing layer except the electroactive area. According to the method, a three-dimensional gold nanowire network is grown on the surface of an insulating glass needle tip in situ through amino silanization modification, gold nanoparticle self-assembly seed crystal and a seed-mediated growth method. The insulating substrate is adopted to reduce background current, and the signal-to-noise ratio is high; the accurate control of the electroactive region is realized through a photoresist patterning process; the preparation process is simple, the cost is low, and the method can be widely applied to the single cell analysis fields of intracellular active oxygen species detection, neurotransmitter detection and the like.

The utility model relates to the field of medical instruments, in particular to an electrochemical immunodetection system. The utility model provides a test card and an electrochemical immunoassay analyzer. The electrode of the test card is inverted, the magnet assembly is arranged above the test card, and the blood cells can be far away from the electrode and the magnetic beads due to natural sedimentation in the incubation process by utilizing the density difference between the blood cells and the plasma, so that the plasma content around the electrode is increased, the blood cell content around the electrode is reduced, and the background current of detection is reduced; the detection sensitivity is improved. In addition, the magnet assembly is arranged in the instrument, so that the requirements of the test card on use and storage conditions are reduced, and the processing difficulty and the use cost of the test card are also reduced.

The invention relates to the technical field of beta activity measurement, in particular to an ionization chamber beta activity measuring device which comprises a top cover and a handle, the handle is fixedly connected to the upper surface of the top cover, a plurality of grooves are formed in the top cover, nuts are in clearance fit with the interiors of the grooves, screws are fixedly connected to the lower portions of the nuts, and the screws are fixedly connected to the upper surface of the top cover. The outer wall of the screw rod is in threaded connection with the shell, and the upper end of the shell is attached to the top cover. The device adopts a beta activity measuring device designed by a small cylindrical ionization chamber, adopts the ionization chamber as a detector, designs a micro-current measuring system with an automatic range conversion function, also designs automatic compensation and current calibration functions, can deduct a background current value, and finally converts the background current value into the radioactive activity of the energy nuclide through automatic operation. The device can be installed in a hot chamber, a shielding chamber and a glove box for use, the beta activity of the radioactive material of 10 mCi to 20 Ci can be accurately measured, the measurement uncertainty is smaller than or equal to 5% (k = 1), and a user can conveniently and accurately master the beta activity in the measured sample material.