Abstract: A low-cost modular liquid nitrogen low-temperature multi-nuclear magnetic resonance probe includes a Dewar, a pluggable coil and a front-end gain amplifier. The Dewar includes a cylindrical sandwich chamber, the center of the cylindrical sandwich chamber constitutes a room-temperature chamber, a sandwich of the cylindrical sandwich chamber is divided into a vacuum chamber and a liquid nitrogen chamber by a liquid nitrogen vessel wall, the vacuum chamber is located between the room-temperature chamber and the liquid nitrogen chamber, the pluggable coil and the front-end gain amplifier are provided in the vacuum chamber, the pluggable coil comprises a coil portion and a pluggable base, the coil portion is in pluggable connection with the pluggable base, and the pluggable coil is connected with the front-end gain amplifier. The probe realizes the transmission of radio frequency pulses and the reception of magnetic resonance signals, and is applicable to whole-body imaging of a small animal.

Abstract: A method for separating oil-water two-phase NMR signals by using dynamic nuclear polarization comprising: using a combination of a non-selective free radical and a selective relaxation reagent to selectively enhance an NMR signal of an oil phase or a water phase, the relaxation reagent being capable of selectively suppressing dynamic polarization enhancement of the water phase or oil phase, thus achieving the polarization enhancement of a single fluid phase in the mixed fluid phases and realizing separation of the two-phase signals; or using a selective free radical to selectively enhance the NMR signal of the oil phase or the water phase, thus achieving the polarization enhancement of a single fluid phase in the mixed fluid phases and realizing separation of the oil-water two-phase NMR signals. The method is simple and easy to operate, has a short test time, and can efficiently separate NMR signals of oil and water phases.

Abstract: Provided are a search request processing method, an apparatus, a computer device, a storage medium, a computer product, and a computer program. The method includes: in response to a search instruction, sending a search request comprising a target question; acquiring a plurality of sets of answer information corresponding to the target question, wherein each set of answer information includes answer summary information and a multimedia content supporting the answer summary information; the genre of the multimedia content is determined on the basis of a category of the target question, and the answer summary information is extracted on the basis of the multimedia content; and displaying the answer summary information in each set of answer information on a search result page, and displaying, when any piece of answer summary information is selected, at least part of the multimedia content supporting the selected answer summary information.

Abstract: A low-cost modular liquid nitrogen low-temperature multi-nuclear magnetic resonance probe includes a Dewar, a pluggable coil and a front-end gain amplifier. The Dewar includes a cylindrical sandwich chamber, the center of the cylindrical sandwich chamber constitutes a room-temperature chamber, a sandwich of the cylindrical sandwich chamber is divided into a vacuum chamber and a liquid nitrogen chamber by a liquid nitrogen vessel wall, the vacuum chamber is located between the room-temperature chamber and the liquid nitrogen chamber, the pluggable coil and the front-end gain amplifier are provided in the vacuum chamber, the pluggable coil comprises a coil portion and a pluggable base, the coil portion is in pluggable connection with the pluggable base, and the pluggable coil is connected with the front-end gain amplifier. The probe realizes the transmission of radio frequency pulses and the reception of magnetic resonance signals, and is applicable to whole-body imaging of a small animal.

Abstract: An intelligent decision-making method for maintaining urban underground sewer network includes steps of: analyzing with a sewer network functional defect three-dimensional instantaneous hydraulic model; calibrating parameters by finite element fitting analysis and full-scale test, and verifying accuracy of the sewer network functional defect three-dimensional instantaneous hydraulic model; combining node water level iteration method, Preissmann slit method, Godunov finite volume method and unstructured grid to rebuild a surface-subsurface one-two-dimensional coupled connection model; using R language, dynamic library linking technology, and long-short-term memory neural network method of multi-source data samples for engineering secondary development of the surface-subsurface one-two-dimensional coupled connection model, and obtaining urban sewer network functional defect conditions with waterlogging result labels; and establishing a multi-objective planning intelligent decision-making model for sewer network

Abstract: The present invention belongs to the technical field of analysis and detection and provides a method for detecting a selenoamino acid in a selenoprotein. The detection method includes: (1): mixing 10-30 mg of a selenoprotein sample with hydrochloric acid, and hydrolyzing with microwaves at 140-170° C. for 10-40 min to obtain a hydrolysate; (2): adjusting pH of the hydrolysate to 6-8 to obtain a pretreated solution; and, (3): detecting a selenoamino acid in the pretreated solution with high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS) to obtain a content of the selenoamino acid. The method is simple in operation and provides an accurate and reliable result, and also reduces time and cost.

Abstract: A compound double coaxial line atmospheric pressure low-temperature microwave plasma jet source includes an outer coaxial line, and an inner coaxial line arranged inside the outer coaxial line. The outer coaxial line includes a tube body. A metal tube is arranged in the tube body. A short-circuit plunger is arranged at the bottom of the metal tube. The inner coaxial line includes a needle electrode, and the needle electrode is arranged in the metal tube. A first gas inlet is arranged on the tube body, and the first gas inlet is connected between the tube body and the metal tube. A second gas inlet is arranged at the bottom of the metal tube, and the second gas inlet is connected between the metal tube and the needle electrode. The tube body is further provided with a microwave input port, and the microwave input port is connected to the metal tube.

Abstract: The present invention belongs to the technical field of analysis and detection and provides a method for detecting a selenoamino acid in a selenoprotein. The detection method includes: (1): mixing 10-30 mg of a selenoprotein sample with hydrochloric acid, and hydrolyzing with microwaves at 140-170° C. for 10-40 min to obtain a hydrolysate; (2): adjusting pH of the hydrolysate to 6-8 to obtain a pretreated solution; and, (3): detecting a selenoamino acid in the pretreated solution with high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS) to obtain a content of the selenoamino acid. The method is simple in operation and provides an accurate and reliable result, and also reduces time and cost.

Abstract: A compound double coaxial line atmospheric pressure low-temperature microwave plasma jet source includes an outer coaxial line, and an inner coaxial line arranged inside the outer coaxial line. The outer coaxial line includes a tube body. A metal tube is arranged in the tube body. A short-circuit plunger is arranged at the bottom of the metal tube. The inner coaxial line includes a needle electrode, and the needle electrode is arranged in the metal tube. A first gas inlet is arranged on the tube body, and the first gas inlet is connected between the tube body and the metal tube. A second gas inlet is arranged at the bottom of the metal tube, and the second gas inlet is connected between the metal tube and the needle electrode. The tube body is further provided with a microwave input port, and the microwave input port is connected to the metal tube.

Abstract: A rotor temperature monitoring method and system for a permanent magnet synchronous motor are provided. According to the method and system, an a-phase line current and a b-phase line current of a stator of a permanent magnet synchronous motor are obtained as a first line current and a second line current; further, a line voltage between the a-phase and the b-phase of the stator is obtained and a rotating speed of the rotor of the permanent magnet synchronous motor is obtained; and then, the first line current, the second line current, the line voltage, the rotating speed of the rotor, an inductance parameter of the permanent magnet synchronous motor and a temperature characteristic equation of a permanent magnet of the rotor are substituted into a preset rotor permanent magnet temperature expression to calculate and obtain the temperature of the rotor.

Abstract: A control method for restarting a permanent magnet synchronous motor (PMSM) in a rotating condition, and a device and a system thereof are provided. In the method, an electrical angular speed ?e of the PMSM is obtained based on a speed of a trailer to obtain a back electromotive force of the PMSM. The back electromotive force is compared with a voltage at a side of an inverter, and if the electromotive force of the permanent magnet synchronous motor is higher than the voltage at the side of the inverter, the restarting of the PMSM is forbidden, otherwise, the restarting of the PMSM is allowed. Therefore, in the present disclosure, the low-speed operating condition and the high-speed operating condition correspond to different position angles of the rotor, and the PMSM is started based on the position angle of the rotor.

Abstract: A direct-axis current protection method and device for a permanent magnet synchronous motor drive system. The method includes: pre-calculating the direct-axis current of the next moment according to the current voltage transmitted from an inverter to a permanent magnet synchronous motor (PMSM); comparing the direct-axis current of the next moment with a maximum protection current; if the direct-axis current of the next moment is less than the maximum protection current, continuing transmitting the current voltage to the PMSM; if the direct axis current of the next moment is greater than or equal to the maximum protection current, redistributing the voltage according to a protection direct-axis current and a protection quadrature-axis current, and transmitting the redistributed voltage to the PMSM. The direct-axis current of the next moment is tended to be normal by adjusting the voltage.

Abstract: A method and device for acquiring a rotor position based on a permanent magnet synchronous drive system. The permanent magnet synchronous drive system includes an inverter and a permanent magnet synchronous motor, wherein the initial speed of the permanent magnet synchronous motor is not zero. The method includes: controlling a bridge arm switch of an inverter periodically; collecting a three-phase current of the permanent magnet synchronous motor at a fixed time within each control period; and after the three-phase current is reversed, sending same to a phase-locked loop system to conduct processing, so as to obtain a phase angle of an induction potential vector, and according to the phase angle of the induction potential vector, acquiring a rotor position angle of the permanent magnet synchronous motor.

Abstract: A rotor temperature monitoring method and system for a permanent magnet synchronous motor are provided. According to the method and system, an a-phase line current and a b-phase line current of a stator of a permanent magnet synchronous motor are obtained as a first line current and a second line current; further, a line voltage between the a-phase and the b-phase of the stator is obtained and a rotating speed of the rotor of the permanent magnet synchronous motor is obtained; and then, the first line current, the second line current, the line voltage, the rotating speed of the rotor, an inductance parameter of the permanent magnet synchronous motor and a temperature characteristic equation of a permanent magnet of the rotor are substituted into a preset rotor permanent magnet temperature expression to calculate and obtain the temperature of the rotor.

Abstract: A method and device for acquiring a rotor position based on a permanent magnet synchronous drive system. The permanent magnet synchronous drive system includes an inverter and a permanent magnet synchronous motor, wherein the initial speed of the permanent magnet synchronous motor is not zero. The method includes: controlling a bridge arm switch of an inverter periodically; collecting a three-phase current of the permanent magnet synchronous motor at a fixed time within each control period; and after the three-phase current is reversed, sending same to a phase-locked loop system to conduct processing, so as to obtain a phase angle of an induction potential vector, and according to the phase angle of the induction potential vector, acquiring a rotor position angle of the permanent magnet synchronous motor.

Abstract: A control method for restarting a permanent magnet synchronous motor (PMSM) in a rotating condition, and a device and a system thereof are provided. In the method, an electrical angular speed ?e of the PMSM is obtained based on a speed of a trailer to obtain a back electromotive force of the PMSM. The back electromotive force is compared with a voltage at a side of an inverter, and if the electromotive force of the permanent magnet synchronous motor is higher than the voltage at the side of the inverter, the restarting of the PMSM is forbidden, otherwise, the restarting of the PMSM is allowed. Therefore, in the present disclosure, the low-speed operating condition and the high-speed operating condition correspond to different position angles of the rotor, and the PMSM is started based on the position angle of the rotor.

Abstract: A direct-axis current protection method and device for a permanent magnet synchronous motor drive system. The method includes: pre-calculating the direct-axis current of the next moment according to the current voltage transmitted from an inverter to a permanent magnet synchronous motor (PMSM); comparing the direct-axis current of the next moment with a maximum protection current; if the direct-axis current of the next moment is less than the maximum protection current, continuing transmitting the current voltage to the PMSM; if the direct axis current of the next moment is greater than or equal to the maximum protection current, redistributing the voltage according to a protection direct-axis current and a protection quadrature-axis current, and transmitting the redistributed voltage to the PMSM. The direct-axis current of the next moment is tended to be normal by adjusting the voltage.

Abstract: A multiple I/O interfacing system for a storage device and communicating method for the same are disclosed. The present invention is particularly embodied in the storage product of a computer system, where it implements a high-reliability connection between the processing units of at least two input/output cards. The preferred embodiment of the multiple I/O communicating method includes a first step of periodically broadcasting commands and data packets by the processing units for each I/O card. Simultaneously the processing units determine if any communication path fails. If there is no failed path, a first path is preferably being a master path, and a second path is being a secondary path. If one of the paths fails, the other one will be the communication path since a redundant mechanism activates. Next, the failure message will be sent to system unit the failure is eliminated.