8 results about "Transverse magnetization" patented technology

The application discloses a kind of magnetic flux leakage testing device, including body, rotating assembly, detection component and tracking component, rotating assembly rotation is set on body and is used to rotate around steel pipe axis, detection component includes longitudinal magnetizer, transverse magnetizer and probe component, longitudinal magnetizer is set on rotating assembly, transverse magnetizer is set on body, both are spaced along steel pipe axial direction, to form longitudinal detection area and transverse detection area, probe component is set on rotating assembly, and respectively located longitudinal detection area and transverse detection area, tracking component includes rack and follow-up structure, probe component is installed on follow-up structure, follow-up structure is used to drive probe component to be close or far from the movement relative to steel pipe surface, probe component has at least one translational degree of freedom and / or at least one rotational degree of freedom relative to tracking component, to solve the technical problem that two direction defects are difficult to realize continuous, integrated detection in the same detection equipment in prior art.

The invention discloses a non-diagnostic method for selectively detecting glycine molecules in a mixed system based on magnetic resonance optimal control pulses, which is characterized in that the evolution of nuclear spin quantum states of mixed molecules including the glycine molecules is simultaneously controlled by utilizing broadband excited optimal control pulses; before and after the optimized pulse is applied, a magnetization vector of glycine molecule nuclear spinning is always in a z direction, and transverse magnetization vectors of other molecules are dispersed by applying gradient pulse, so that retention and selective detection of glycine magnetic resonance signals are realized. The method has a wide application scene.

Disclosed in the present invention are a 3D navigator-based 3D gradient spin-echo diffusion imaging method, and a device. The method comprises: first, using a global saturation module to destroy previous residual transverse magnetization; second, by means of a diffusion encoding module, embedding a pair of trapezoidal cosine oscillation gradients or pulse gradients into radio frequency pulses of 90°x-180°y-90°-x, and separating diffusion encoding from signal acquisition; then using a fat saturation module to suppress a fat signal; using a 3D gradient spin-echo readout method to acquire an image signal; and finally, acquiring a 3D navigation echo signal in the last spin echo for correcting a phase error between multiple excitations. The present invention can effectively eliminate phase errors between multiple acquisitions and realize high-resolution whole-brain diffusion imaging. Compared with 2D echo planar imaging, the present invention increases the signal-to-noise ratio of diffusion magnetic resonance imaging, thereby supporting higher-resolution whole-brain 3D diffusion magnetic resonance imaging.

A method and a magnetic resonance imaging (MRI) system improve an MRI signal from a magnetization of interest. The method includes performing an MRI pulse sequence containing three consecutive radio frequency (RF) elements, namely, a first element that is an inversion-recovery pulse sequence characterized by a time of inversion, a second element that is an image-encoding pulse sequence starting at the time of inversion with an excitation RF pulse followed by an image-encoding gradient and a data sampling. The second element is followed by a third element. An MRI signal generated by the object and sampled by image readout blocks applied to the object by the MRI system during each repetition time, is acquired. From the MRI signal, an image of the object is reconstructed. The third element is a modified driven-equilibrium (mDE) pulse sequence configured for achieving a conversion of a transverse magnetization component.

The application provides a magnetic flux reverse type axial flux motor, which comprises a first stator, a second stator and a rotor, the first stator and the second stator comprise a stator core, a permanent magnet and an armature winding, the permanent magnet is composed of an axial magnetization permanent magnet and a transverse magnetization permanent magnet, and is embedded into the stator core tooth top in an alternating pole mode, the aggregation of permanent magnet flux is realized, and the back electromotive force waveform is improved. The rotor comprises a first rotor core, a second rotor core and a magnetic separation disc, the rotor core is laminated by silicon steel sheets, the first rotor core and the second rotor core are opposite to the first stator and the second stator respectively, and an air gap surface is arranged between the opposite rotor core and the stator, and the magnetic separation disc realizes the decoupling of the double air gap magnetic circuit. The first stator and the second rotor core are arranged in a staggered mode with the second stator and the second rotor core to offset part of the cogging torque and reduce the torque ripple.

Method for operating a magnetic resonance tomograph for spatially resolved spin resonance measurement of an object, in particular a living object, which is arranged in a static magnetic field B0, whereby an alignment of the object's spins and a longitudinal net magnetization Mz along the direction Z of the static magnetic field results, and wherein a transverse magnetization component Mxy is generated or changed, in particular by generating a spin flip from the Z direction by a desired flip angle, in particular by 90 degrees, by means of at least one high-frequency excitation pulse (1) in spin resonance, wherein spin echo signals from at least one desired volume element of the object are measured using a sequence of high-frequency pulses (4, 5, 7) and switched gradient magnetic fields (2, 3, 6).wherein the at least one volume element is determined by several gradient magnetic fields superimposed at least temporarily on the homogeneous magnetic field B0, wherein the sequence of high-frequency pulses comprises a first (4) and a second high-frequency rephasing pulse (5), in particular a first (4) and second high-frequency rephasing pulse (5) directly after the generation of a transverse magnetization component by means of a high-frequency excitation pulse (1), wherein from the second high-frequency rephasing pulse (5) onwards both a spin echo and a stimulated echo are generated, wherein in addition to a gradient magnetic field (6) in the frequency coding direction, which is switched on during the measurement acquisition to acquire a line of the raw data space, an additional gradient magnetic field (8) in the frequency coding direction is switched on, which generates echo signals or echo signal components newly generated by the high-frequency rephasing pulses (5, 7),in particular, those not attributable to a refocusing of the original spin echo after the first radio frequency rephasing pulse (4) and / or of the original stimulated echo after the second radio frequency rephasing pulse (5), are shifted out of the raw data space or raw data line acquired in a subsequent measurement, characterized in that, during an evolution time (Tau) between the first (4) and second radio frequency rephasing pulse (5), T2*-induced relaxation processes act on a transverse magnetization component present after the first radio frequency rephasing pulse (4), and a magnetization component present in the longitudinal direction after the first radio frequency rephasing pulse (4) remains unaffected, wherein the absolute time between the first (4) and second radio frequency rephasing pulse (5) is extended by the evolution time beyond the duration of an echo interval,which is present between subsequent equidistant high-frequency rephasing pulses (5, 7).

The application relates to a magnetic resonance image generation method and device, computer equipment and a storage medium. The method comprises the following steps: in a target cardiac cycle, a preparation module is applied in response to receiving an electrocardio trigger signal to flip a first initial longitudinal magnetization vector corresponding to a detection object into a first transverse magnetization vector and to scatter into a first vector value; an inversion recovery pulse is applied in response to reaching a vector recovery time after the preparation module is applied; magnetic resonance data of the detection object is acquired by using a target imaging sequence in response to reaching an inversion recovery time after the inversion recovery pulse is applied; and the magnetic resonance data is reconstructed to obtain a target magnetic resonance image of the detection object. The method ensures that the longitudinal magnetization vector corresponding to the detection object is recovered from the first vector value to the signal strength of the vector recovery time before the inversion recovery pulse is applied at the interval vector recovery time, so that the longitudinal magnetization vectors corresponding to the detection object are all the same, and the quality of the magnetic resonance image is improved.

The invention discloses a system and a method for measuring a three-dimensional magnetic field by using an integrated micro-ring device, and belongs to the technical field of optical fiber sensing and magnetic field measurement. The system comprises a light source, a transmission straight waveguide, a polarization controller, a 1: 2 type Y waveguide, two sensing micro-rings (built-in magneto-optical waveguides) perpendicular to each other and a photoelectric detector. According to the invention, by using the asymmetry of the magneto-optical waveguide in the horizontal / vertical direction, transverse magnetization respectively changes TE / TM mode propagation constants; the x / y-axis magnetic field and the z / y-axis magnetic field are sensed through the two micro-rings respectively, and a three-dimensional magnetic field is obtained through simultaneous operation. The device is high in integration level, small in size, simple in process and high in environmental adaptability, and has practical value. According to the invention, each micro-ring measuring device is integrated on a single chip, the integration level is relatively high, the size is small, the process is relatively simple, and the method has relatively high environmental adaptability and practical value.