57 results about "Spin magnetic moment" patented technology

A nuclear magnetic resonance sensing apparatus and method for operating in an earth borehole comprises a source of switchable magnetic field to polarize nuclei in the region of interest, said source comprising a coil wound on a magnetic core having controllable residual magnetization. Maintaining the magnetization of the core during a polarization interval does not require steady current in the coil. Switching intensity and polarity of magnetization of the core causes precession of spin magnetic moments of the nuclei; the precession induces a signal indicative of nuclear magnetic resonance properties of earth formations.

The invention provides an MRAM storage unit. The unit comprises two magnetic tunnel junctions and a spin orbital moment providing line, the two magnetic tunnel junctions are located on the surface ofthe same side of the spin orbital moment providing line, wherein the free layer of each magnetic tunnel junction is close to the spin orbital moment providing line, the magnetization directions of thereference layers of the two magnetic tunnel junctions are the same, and the spin orbital moment providing line is used for applying spin magnetic moments in opposite directions to the two magnetic tunnel junctions, so that the free layers of the two magnetic tunnel junctions have opposite magnetization directions. According to the MRAM storage unit, complementary resistance states can be stored,differential signals are formed during state reading, the reading error rate is reduced, and the data reading speed can be remarkably increased.

The invention provides a microwave aging treatment method for cobalt-based rare earth permanent magnetic materials. Cobalt-based rare earth permanent magnetic material sintered blanks prepared by a powder metallurgy method are treated in a second-stage artificial aging or multi-stage artificial aging manner after the heating and the heat preservation in a microwave manner; by utilizing the high-frequency electromagnetic field of microwaves, on one hand, the electron spin magnetic moment orientation of 3d casing layers of transition metals in alloys is affected, the bonding energy between the transition metals and rare earth metals is weakened, the nucleation potential barriers of new Sm2Co17R phrases and SmCo5 phrases are reduced, nanocrystalline particles containing the Sm2Co17R phrases and the SmCo5 phrases are beneficial to form, and high saturation magnetization intensity and high mechanical property can be obtained; on the other hand, the microwaves can be converted into the diffused energy of atoms, the diffused speed of the atoms is increased, the sintering progress is accelerated, and the cell-shaped structures are refined. For the rare earth permanent magnetic materials treated by the method, the cell-shaped structures can be small and uniform. The method can be applied to prepare rare earth permanent magnetic materials which contain Sm (samarium), Co (cobalt), Fe (ferrum), Cu (copper), Zr (zirconium) or Ti (titanium) and have good mechanical property and high mechanical property, so that the method is suitable for industrialized application.

The present invention relates to a magnetic resonance structure with a cavity or a reserved space that provides contrast and the additional ability to frequency-shift the spectral signature of the NMR-susceptible nuclei such as water protons by a discrete and controllable characteristic frequency shift that is unique to each MRS design. The invention also relates to nearly uniform solid magnetic resonance T₂* contrast agents that have a significantly higher magnetic moment compared to similarly-sized existing MRI contrast agents.

The invention discloses a system for quick measurement of the magnetic moment of a spacecraft in a terrestrial magnetic field. According to the system, the magnetic moment of the spacecraft is measured through the combination of the magnetic flux method and the terrestrial magnetic orientation method. The system comprises a lengthwise guide rail and a rotary table capable of achieving autogiration and arranged on the guide rail in a sliding mode, wherein the rotary table is used for supporting the spacecraft and enabling the spacecraft to rotate around the rotary table for measurement of the magnetic moment of the spacecraft, five vertical magnetic flux induction coils are arranged in the middle of the guide rail in parallel and are supported by a supporting device, the guide rail penetrates through the five magnetic flux induction coils to enable the rotary table to penetrate through the centre of the magnetic flux induction coils in a sliding mode, and the five magnetic flux induction coils are electrically connected with a fluxmeter through wires respectively to transmit a measured magnetic flux signal to a data processing system through the fluxmeter. The invention further discloses a method for quick measurement of the magnetic moment by means of the system. When the magnetic moment of the spacecraft is measured through the combination of the magnetic flux method and the terrestrial magnetic orientation method, the spacecraft magnetic moment measurement period is shortened, real magnetic moment in two directions can be measured, and testing precision is improved.

This invention relates to methods and devices for propulsion through a fluid, in particular at low Reynolds number. We describe a method of propelling one of a magnetic device and a fluid relative to the other, the magnetic device comprising a pair of magnetic moments linked by an elastic coupling element, one of said moments having a greater resistance to a change in orientation due to an external applied magnetic field than the other, the method comprising applying an elliptical or ellipsoidal rotating magnetic field to the device to cause a change in mutual attraction or repulsion between said magnetic moments to thereby change a physical configuration of said device, propelling said device relative to said fluid.

The invention relates to a non-magnetic rotary table used for measuring the magnetic moment of a satellite in a low-magnetic environment magnetic field. The non-magnetic rotary table comprises a trolley used for moving equipment, universal wheels mounted on the bottom face of the trolley, a sitting type rolling bearing arranged at the center of the upper surface of the trolley, a revolving platform arranged above the sitting type rolling bearing and a support mounted on the upper surface of the revolving platform. A bevel gear is arranged between the sitting type rolling bearing and the revolving platform and connected to a rotation measurement transmission mechanism. A transposition transmission mechanism used for transposition transmission is arranged on the support. The transposition transmission mechanism is connected to a transposition hand wheel. A fixture used for fixing and tightly clamping the satellite is arranged on the support. The non-magnetic rotary table used for measuring the magnetic moment of the satellite is reasonable in technology, convenient to operate and low in manufacturing cost; the sitting type rolling bearing and a limiting device are used, so that the non-magnetic rotary table is high in design stability coefficient and ensures the safety of the satellite at the time of horizontal movement, transposition and rotation; a positioning device is used for guaranteeing the accuracy of the position of measuring points, and the non-magnetic rotary table can be applied to magnetic moment measurement for various satellites.

The invention belongs to the technical field of gravimeters, and discloses a high-precision magnetic suspension relative gravimeter, a control method and application, a magnetic-gravity potential well adopted by the control method of the high-precision magnetic suspension relative gravimeter is realized based on a permanent magnet combination mode, and an anti-magnetic suspension mechanical system is used as a gravity sensitive device, the anti-magnetic suspension is to realize the suspension of the mass body by utilizing the anti-magnetic interaction generated by the spinning magnetic moment in the anti-magnetic material. The gravimeter based on the anti-magnetic suspension system is different from an existing method in the physical principle and is a complete principle innovation. Most importantly, compared with the prior art, the method has the advantages of being capable of working at room temperature, small in size, high in precision and high in stability, other gravimeters cannot have the advantages at the same time at present, and therefore the method has clear advantages in gravity measurement scenes with high requirements for the indexes in the future. The anti-magnetic suspension is completely passive suspension, has very high parameter stability in principle, and realizes low drift.

A method for mapping geological structures of a formation on a side of a surface, includes: generating a magnetic moment using at least one magnetic moment generator to build up a magnetic field in the formation in an on-period, wherein the magnetic moment has a moment strength, and wherein the magnetic moment is positioned on another side of the surface; changing the magnetic moment to change the magnetic field; and making at least one record in a recording device at a recording time t_record in an off-period, wherein the record includes at least a representation of the change in the magnetic field and/or a representation of the magnetic field obtained by a B/E-measuring unit; wherein the on-period is separated from the off-period by the act of changing the magnetic moment.

The invention provides a competitive spin current control-based magnetic random access memory and a preparation method thereof. By applying pulse voltage to a spin orbit coupling layer, the spin orbitmoment effect produced by competitive spin current controls generation of 180-DEG turnover of a magnetic moment of a magnetic free layer in a magnetic tunnel junction, and writing of information is realized. By measuring the change of voltages at two ends of a magnetic tunnel junction, change of tunneling resistance is obtained, and reading of information is achieved.

A method for mapping geological structures of a formation on a side of a surface, includes: generating a magnetic moment using at least one magnetic moment generator to build up a magnetic field in the formation in an on-period, wherein the magnetic moment has a moment strength, and wherein the magnetic moment is positioned on another side of the surface; changing the magnetic moment to change the magnetic field; and making at least one record in a recording device at a recording time t_record in an off-period, wherein the record includes at least a representation of the change in the magnetic field and/or a representation of the magnetic field obtained by a B/E-measuring unit; wherein the on-period is separated from the off-period by the act of changing the magnetic moment.

The invention discloses an electromagnetic docking control method and a device, which adopt an anomalous magnetic moment control plus one-time magnetic moment switching mode, wherein the electromagnetic docking control method includes the following steps: according to the magnetic induction intensity of a target electromagnetic device, the initial speed and initial magnetic moment of a tracking electromagnetic device and the initial distance between the barycenters of the target electromagnetic device and the tracking electromagnetic device, the initial mechanical energy of a docking system is calculated; according to the set switching speed and initial magnetic moment of the tracking electromagnetic device and the initial mechanical energy of the docking system, the switching distance, which corresponds to the switching speed, between the barycenters of the target electromagnetic device and the tracking electromagnetic device is calculated; according to the switching speed, the switching distance and the expected docking speed and expected docking distance of the tracking electromagnetic device, the switching magnetic moment of the tracking electromagnetic device is calculated; when the speed of the tracking electromagnetic device is changed into the switching speed, the electromagnetic moment of the tracking electromagnetic device is transformed into the switching magnetic moment. The invention solves the technical problem that the design of the conventional method is complex and the requirement for control design robustness is high.

The shimming work assistance unit performs singular value decomposition of a response matrix, which represents the relationship between an error magnetic field distribution and an adjusted magnetic moment placement distribution. From the multiple eigenmodes obtained, the eigenmodes are selected and added one by one in order from the eigenmode with the highest singular value, and the residual magnetic field error, which represents the fluctuation range of the difference between the magnetic field distribution, generated by the placement of the shimming magnetic moments corresponding to said eigenmode, and the error magnetic field distribution, is displayed on a display unit as a function graph of eigenmode order (line graph (1)).

The invention discloses an optical excitation method for generating spin-polarized electrons and spin current. Through interaction between an evanescent wave generated by optical total reflection on an interface and a structure which is included by a functional layer generating the spin-polarized electrons and the spin current on the interface, is made of a surface plasmon metal material and has a nanometer characteristic size, a surface plasmon is excited, so that surface free electrons in resonance transition generate spin precession in an effective surface magnetic field of the structure made of the surface plasmon metal material to form a common spin magnetic moment component so as to generate the spin-polarized electrons in the functional layer generating the spin-polarized electrons and thus form the spin current along with spreading of the surface Plasmon on the surface (or interface).

The invention relates to an anisotropic magnetic resistance material and specifically relates to ananisotropic magnetic resistance material with a NiFe alloy magnetic layer. The invention belongs to the technical field of magnetic resistance material. According to the invention, on a regular Ta/NiFe/Ta structural base, a NiO pinning stabilization layer having a certain thickness is added between Ta and NiFe. On one hand, NiO is an anti-ferromagnetic material. When the anti-ferromagnetic material contacts with the magnetic layer, exchange interaction is generated on an interface. With the exchange interaction, the magnetic layer may be pinned in a specific direction, with magnetic moment being stabilized, so that the magnetic layer is not easy to be affected by interference magnetic field. On the other hand, for AMR film material, mirror reflection of conducting electrons on the interface facilitates AMR rate. Oxide/metal growing successively can form the comparatively fat interface, so that mirror reflection of the conducting electrons is enhanced.