Abstract: For constructing an asymmetric RF pulse for an MRI system, a first RF amplitude for a first part of a time interval is determined and an RF amplitude curve, which depends on at least one RF curve parameter is received. A combined RF amplitude curve for the time interval is determined by combining the first RF amplitude for the first part of the time interval and the RF amplitude curve for a second part of the time interval, which succeeds the first part of the time interval. The combined RF amplitude curve is optimized using a loss function, which comprises an energy loss term, which depends on a pulse energy of the combined RF amplitude curve, and using the at least one RF curve parameter as at least one optimization variable. A combined amplitude of the asymmetric RF pulse is given by the optimized combined RF amplitude curve.

Abstract: A level-shifting device structure can include: a level-shifting MOS transistor located in a semiconductor region, where the level-shifting MOS transistor comprises a source region, a drain region, and a doped region; an isolation structure extending from both sides of the doped region to form a closed ring shape, in order to divide the semiconductor region into a high-voltage side region enclosed by the isolation structure and a low-voltage side region located outside the isolation structure; and where the drain region is disposed in the high-voltage side region, and the source region is disposed in the low-voltage side region.

Abstract: A method of controlling a switch-mode converter can include: obtaining an overcurrent reference threshold according to an output voltage sampling signal indicative of an output voltage of the switch-mode converter; and generating an over current protection triggering signal in response to an output current sampling signal indicative of an output current of the switch-mode converter and the overcurrent reference threshold meet a predetermined criterion, thereby triggering the switch-mode converter to enter a protection state.

Abstract: A control circuit for a resonant converter, can include: a feedforward circuit configured to generate a feedforward current; a charge feedback circuit configured to receive a resonant current sampling signal representing a resonant current of the resonant converter in a first mode to generate a charge feedback signal, and to receive the resonant current sampling signal and the feedforward current together to generate the charge feedback signal in a second mode; and a driving control circuit configured to generate driving signals according to the charge feedback signal and a first threshold signal, in order to control switching states of power transistors of the resonant converter, where the first threshold signal is generated according to an error compensation signal representing an error information between a feedback signal of an output signal of the resonant converter and a reference signal.

Abstract: A sampling circuit for a switching power supply, can include: a first sampling circuit configured to acquire a first sampling signal of a current flowing through an inductor in the switching power supply; and a second sampling circuit configured to obtain a compensation signal with a same rising slope as the first sampling signal within a turn-off delay time of a power switch in the switching power supply, and to superimpose the compensation signal on the first sampling signal to generate a second sampling signal.

Abstract: For constructing an asymmetric RF pulse for an MRI system, a first RF amplitude for a first part of a time interval is determined and an RF amplitude curve, which depends on at least one RF curve parameter is received. A combined RF amplitude curve for the time interval is determined by combining the first RF amplitude for the first part of the time interval and the RF amplitude curve for a second part of the time interval, which succeeds the first part of the time interval. The combined RF amplitude curve is optimized using a loss function, which comprises an energy loss term, which depends on a pulse energy of the combined RF amplitude curve, and using the at least one RF curve parameter as at least one optimization variable. A combined amplitude of the asymmetric RF pulse is given by the optimized combined RF amplitude curve.

Abstract: A training method for training neural networks to determine a magnetic susceptibility distribution of a sample may include: storing a simulated magnetic susceptibility map of the sample, generating a modified magnetic susceptibility map by combining an influence of one or more external magnetic susceptibility sources with the simulated magnetic susceptibility map and storing the modified magnetic susceptibility maps. The method may include generating a first training image by applying a quantitative susceptibility mapping model the modified magnetic susceptibility map and storing the first training image, applying the first neural network to the first image and a second neural network to an output of the first neural network and changing network parameters of the first and the second neural network depending on a deviation of an output of the second artificial neural network from the simulated magnetic susceptibility map.

Abstract: A control circuit for a switching converter having a main power switch, the control circuit including: a voltage generation circuit configured to be connected with a common connection terminal of the main power switch and an inductor to receive a drain-source voltage of the main power switch, and to generate a first voltage according to the drain-source voltage; a valley detection circuit configured to generate a valley detection signal according to the first voltage when the drain-source voltage resonates to a valley; and where the control circuit is configured to turn on the main power switch according to the valley detection signal.

Abstract: A multi-modal antenna for use in magnetic resonance applications, the multi-modal antenna including an elongate first conductive element, an elongate second conductive element at least partially aligned with and spaced from the first conductive element and a dielectric material at least partially separating the first and second conducting elements so that the first and second conductive elements are electromagnetically coupled and/or electrically connected, and wherein at least one of the first and second conducting elements are configured to be electromagnetically coupled and/or electrically connected to an RF system so that the multi-modal antenna can at least one of transmit and receive RF electromagnetic signals for performing magnetic resonance imaging or spectroscopy.

Abstract: A communication control circuit for a power supply chip, can include: a main control die having a main control circuit; a plurality of sub-control dice configured to respectively receive a control signal sent by the main control die, where each sub-control die comprises a sub-control circuit; and where a reference ground of each sub-control die is different from a reference ground of the main control die, the reference grounds of the plurality of sub-control dice are different with each other, and communication between the main control die and each sub-control die is achieved by a corresponding level conversion circuit.

Abstract: A control circuit for a switching converter, can include: a current compensation signal generating circuit configured to generate a current compensation signal based on a current sampling signal representing an inductor current; and a control signal generating circuit configured to adjust a current control parameter of a current control loop in the switching converter according to the current compensation signal, in order to increase power factor (PF) and reduce total harmonic distortion (THD).

Abstract: A sampling circuit for a switching power supply, can include: a first sampling circuit configured to acquire a first sampling signal of a current flowing through an inductor in the switching power supply; and a second sampling circuit configured to obtain a compensation signal with a same rising slope as the first sampling signal within a turn-off delay time of a power switch in the switching power supply, and to superimpose the compensation signal on the first sampling signal to generate a second sampling signal.

Abstract: A method of controlling a switch-mode converter can include: obtaining an overcurrent reference threshold according to an output voltage sampling signal indicative of an output voltage of the switch-mode converter; and generating an over current protection triggering signal in response to an output current sampling signal indicative of an output current of the switch-mode converter and the overcurrent reference threshold meet a predetermined criterion, thereby triggering the switch-mode converter to enter a protection state.

Abstract: Provided are a method for obtaining endometrial mesenchymal stem cells from human menstrual blood and the endometrial mesenchymal stem cells prepared thereby. The method include: 1) subjecting an aliquot of menstrual blood to cascade filtration through graded cell strainers of decreasing mesh sizes to separate tissue debris, wherein said cell strainers include a filter-through cell strainer for collecting filtrate and a retention cell strainer for collecting retentate, wherein the mesh size of the retention cell strainer is smaller than that of the filter-through cell strainer; 2) collecting the retentate on the retention cell strainer as the tissue debris; 3) culturing the tissue debris in a mesenchymal stem cells medium; and 4) collecting adherent cells as the endometrial mesenchymal stem cells.

Abstract: A method of controlling a synchronous rectifier circuit can include: adjusting a falling amplitude of a drive voltage of a synchronous rectifier switch in the synchronous rectifier circuit in a pull-down mode; adjusting a shielding time during which the synchronous rectifier switch is in a turn-off shielding mode and is not to be turned off; turning off the synchronous rectifier switch after a drain-source voltage of the synchronous rectifier switch reaches a turn-off threshold; and where the falling amplitude of the drive voltage in the pull-down mode and the shielding time for a current period are adjusted according to an operation state of the synchronous rectifier switch in a previous period.

Abstract: A control circuit for a resonant converter, can include: a feedforward circuit configured to generate a feedforward current; a charge feedback circuit configured to receive a resonant current sampling signal representing a resonant current of the resonant converter in a first mode to generate a charge feedback signal, and to receive the resonant current sampling signal and the feedforward current together to generate the charge feedback signal in a second mode; and a driving control circuit configured to generate driving signals according to the charge feedback signal and a first threshold signal, in order to control switching states of power transistors of the resonant converter, where the first threshold signal is generated according to an error compensation signal representing an error information between a feedback signal of an output signal of the resonant converter and a reference signal.

Abstract: An electronic-part-reinforcing thermosetting resin composition has: a viscosity of 5 Pa·s or less at 140° C.; a temperature of 150° C. to 170° C. as a temperature corresponding to a maximum peak of an exothermic curve representing a curing reaction; and a difference of 20° C. or less between the temperature corresponding to the maximum peak and a temperature corresponding to one half of the height of the maximum peak in a temperature rising range of the exothermic curve.

Abstract: A training method for training neural networks to determine a magnetic susceptibility distribution of a sample may include: storing a simulated magnetic susceptibility map of the sample, generating a modified magnetic susceptibility map by combining an influence of one or more external magnetic susceptibility sources with the simulated magnetic susceptibility map and storing the modified magnetic susceptibility maps. The method may include generating a first training image by applying a quantitative susceptibility mapping model the modified magnetic susceptibility map and storing the first training image, applying the first neural network to the first image and a second neural network to an output of the first neural network and changing network parameters of the first and the second neural network depending on a deviation of an output of the second artificial neural network from the simulated magnetic susceptibility map.

Abstract: A control circuit for a switching converter having a main power switch and a freewheeling circuit, can be configured to: control the freewheeling circuit to be turned on in a first time interval after the main power switch is turned off; control the freewheeling circuit to be turned on in a second time interval after the first time interval, in order to reduce turn-on loss of the main power switch; and where the first time interval and the second time interval do not overlap each other in a switching cycle.