171 results about "Resonance excitation" patented technology

A method of inhibiting the reaction between ions of opposite polarity is disclosed. The method includes exposing a population of ions to a resonance excitation frequency during a mass-to-charge altering reaction between a first subpopulation of ions and a second subpopulation of ions, the resonance excitation frequency being tuned to inhibit the mass-to-charge altering reaction between an ion of the first subpopulation of ions having a predetermined mass-to-charge ratio and an ion of the second subpopulation of ions so that when an ion of the first subpopulation of ions attains the predetermined mass-to-charge ratio, the ion having the predetermined mass-to-charge ratio is selectively inhibited from reacting with ions of the second subpopulation of ions.

The invention provides a magnetic coupling resonance-typed wireless energy transmission device, relating to the field of wireless energy transmission and solving the shortage that the prior art can not carry out the transmission with the barrier or has short transmission distance. The magnetic coupling resonance-typed wireless energy transmission device consists of an energy emission source and an energy receiver; by virtue of the two electromagnetic systems with the same special resonance frequency, with a certain distance, the energy transmission is carried out as the resonance is generated owing to the identical vibration frequency. The energy emission source consists of a magnetic field resonance excitation and driving circuit and a resonance emission circuit; the resonance emission circuit consists of a resonance emission coil and a resonance emission capacitor; the energy receiver consists of a resonance receiving circuit and a high-frequency rectifier circuit; the resonance receiving circuit consists of a resonance receiving coil and a resonance receiving capacitor; the magnetic field is generated by the resonance emission coil; the resonance receiving coil and the magnetic field have the same oscillation frequency and generates the magnetic resonance; the energy in the resonance receiving coil is continuously collected and can be subsequently provided to the loads through the high-frequency rectifier circuit. The magnetic coupling resonance-typed wireless energy transmission device has the advantages of long transmission distance and no barriers.

The invention belongs to the quality analysis technology field and in particular relates to a method of using a plurality of ion traps for the tandem mass spectrometric analysis, including that a high frequency capturing electric field based on a quadrupole field is produced in the first ion trap for capturing ions with various mass-to-charge ratios. A dipolar excitation alternating electric field with certain frequency along the direction of a straight line for connecting the center of the first ion trap center with the center of a second ion trap center is produced in the first ion trap. Thus, the ions with a mass-to-charge ratio oscillate along the direction to reach to the large amplitude under the resonance excitation. Furthermore, a discharged pulse electric field generates in a specific phase of the first ion trap. The ions reaching to the large moving amplitude are discharged and enter the second ion trap. And the ions with other mass-to-charge ratios are still left in the first ion trap. Through a deceleration field added in the second ion trap or the gas collision, the entering ions or byproduct ions are captured and the researching analysis is further made in the second ion trap.

Vibrational energy harvesting (VEH) structures that include resonant beams each having a fundamental resonance frequency and a parametric mode frequency and including at least one piezoelectric layer for generating electrical charge in response to each of fundamental-resonance excitation and parametric-mode excitation of that beam. Circuitry is provided for harvesting the electrical charge from the resonant beam. In some embodiments, the parametric mode frequency of the beam is tuned to be close to its fundamental resonance frequency so as to increase the effective bandwidth of a VEH structure. The effective bandwidth of a VEH structure can be further increased by tuning ones of multiple parametric-mode-enabled resonant beams to slightly different fundamental resonance frequencies and parametric mode frequencies.

A method for magnetic resonance imaging (MRI) is provided. A magnetic resonance excitation is provided. A plurality of k-space echoes is acquired bi-directionally wherein at least one echo is an even echo acquired in a first direction and at least one echo is an odd echo acquired in a second direction opposite from the first direction. K-space echo realignment is corrected between the even and odd echoes. Field inhomogeneity induced artifacts are corrected. Chemical shift induced artifacts between at least two species are corrected.

The invention belongs to the technical field of mass analysis, in particular to a tandem mass spectrometry analysis method performed in ion traps. The method comprises ion selective isolation, collision induced dissociation and quality scanning analysis. Dipole excitation voltages with asymmetric wave shapes are imposed on a pair of electrodes to generate dipole direct voltages, so that isolated parent ions obtain energy to be excited, collided with neutral molecules in the ion traps and dissociated, and tandem mass spectrometry analysis is achieved. The tandem mass spectrometry analysis method performed in ion traps has the advantages that additional direct current power supplies are not needed, and the dipole direct voltages can be obtained only through the control of software, and experiment devices and methods can be simplified apparently. Simultaneously, the parent ions are subjected to a non-resonance excited dissociation mode under the action of the dipole direct voltages, and abundant ion fragment information can be given through the non-resonance excitation of collision and dissociation.

A magnetic resonance imaging system includes a magnetic resonance imaging scanner (10) that performs an inversion recovery magnetic resonance excitation sequence (70) having a blood-nulling inversion time (60) determined based on a blood T1 value appropriate for a selected magnetic field and blood hematocrit, whereby magnetic resonance of blood is substantially nulled. The inversion recovery excitation sequence (70) includes an inversion radio frequency pulse (74) applied with a small or zero slice-selective magnetic field gradient pulse to avoid inflow effects, and an excitation radio frequency pulse (80). The inversion pulse (74) and excitation pulse (80) are separated by the inversion time (60). The magnetic resonance imaging scanner (10) subsequently performs a readout magnetic resonance sequence (72) or spectroscopy sequence to acquire a magnetic resonance signal from tissue other than the nulled blood. A reconstruction processor (44) generates a reconstructed image from the acquired magnetic resonance signal.

A method for estimating values of a field map to generate a magnetic resonance display image with species separation is provided. A set of MR images is acquired based on an applied magnetic resonance excitation. A set of feasible field map values for each pixel in a field map are determined from the set of MR images. Estimated values of the field map for each pixel are chosen from the set of feasible field map values using a combinatorial optimization algorithm that includes a smoothness constraint. The combinatorial optimization algorithm includes iteratively communicating, between neighboring pixels in the field map, sum-product belief messages that include likelihoods for feasible field map values. Field map values are fixed to most likely field map values if the pixel satisfies the smoothness constraint with its neighboring pixels. A magnetic resonance display image with species separation is generated using the estimated field map.

The invention relates to a linear ion trap analyzer. The linear ion trap analyzer comprises an ion trapping space surrounded by a plurality of cylinder electrodes, wherein high frequency voltage is applied to at least one part of cylinder electrodes so as to generate a radial trapping electric field which mainly has two dimensional quadrupole fields in the trapping space; at least one ion leading-out slot is formed on an ion trap in the direction perpendicular to a center axis, and an alternating electric field for exciting dipoles is overlapped in the direction; a strip-type field regulating electrode is arranged in a slit in the cylinder electrode right opposite to the ion leading-out slot, or in the gap between two cylinder electrodes; and the voltage on the field regulating electrode is set as the sum of all or one part of the high frequency voltage on the adjacent cylinder electrode and direct current (DC) voltage, and the DC voltage can be regulated as required. By setting the field regulating electrode and regulating the DC voltage, one or more aims of optimizing a field form in a linear ion trap and influencing ion motion characteristics during resonance excitation can be fulfilled.

In a mass spectrometer in which a high ion dissociation efficiency is possible, inserted electrodes are arranged with a form divided into two or more in the axial direction of the ion trap, an electric static harmonic potential is formed from a DC voltage applied to the inserted electrodes, and with an Supplemental AC voltage applied, ions in the ion trap are oscillated between the divided inserted electrodes in the axial direction of the ion trap by resonance excitation, and the ion with a mass/charge ratio within a specific range is mass-selectively dissociated. Thus, a high ion dissociation efficiency is realized by the use of ion trap of the present invention.

A tandem mass spectrometer is provided in the present invention. The mass spectrometer includes an ion source, a quadrupole mass filter located at downstream side of the ion source, a linear ion trap disposed at downstream side of the mass filter and an ion detector placed on the side of the ion trap, all of which are placed in a vacuum environment. The instrument can obtain MS meeting the standard spectral library search criteria by the quadrupole mass filter cooperating with linear ion trap, realize any multi-stage MS under two modes of axial collision and resonance excitation, and predict and optimize the inflow amount and types of samples under the ion trap analysis mode by the quadrupole. A tandem MS analysis method is also provided, which can repeatedly provide precursor ion selection, ion acceleration, achieve high-energy collision dissociation, low product ion mass discrimination effect.

The invention discloses a micro-domain laser probe component analyzer based on optical fiber waveguide. The analyzer comprises a Nd:YAG laser, a wavelength-tunable laser, a CCD monitoring camera, a computer, a grating spectrometer, a focusing objective lens, a displacement platform, a digital delay pulse generator, and an enhanced CCD. The focusing lens is a reflective focusing lens. The Nd:YAG laser and the wavelength-tunable laser both adopt optical fiber waveguide for carrying out laser pulse transmission; laser pulse is collimated by using an optical fiber collimator and expanded by a beam expander, and enters the focusing objective lens. Laser pulse transmitted by the Nd:YAG laser burns a surface micro-domain on a sample to be analyzed, such that plasma is formed; the laser pulse transmitted by the wavelength-tunable laser is applied on the plasma, such that resonance excitation is caused; one end of the optical fiber is used for collecting spectral signal transmitted by the plasma, and the other end is connected with an optical fiber interface of the grating spectrometer. According to the invention, precise qualitative and quantitative analysis of laser probe upon substance micro-domain components can be realized.

A method of and apparatus for analyzing a substance takes a stream of ions in said substance and supplies the ions to a collision cell including a quadrupole rod set for guiding the ions and a buffer gas. An RF voltage is applied to the quadrupole rod set to guide ions. An additional alternating current signal is applied to the quadrupole rod set at a frequency selected to cause resonance excitation of the secular frequency of a desired ion, whereby said desired ions are excited and undergo collision with the buffer gas causing fragmentation. The alternating current signal is then modulated, whereby periods in which said alternating current signal is applied alternate with periods in which said alternating signal is not applied. The ion spectrum after fragmentation is collected to generate one set of data for one spectrum, representative of the ion spectrum when the alternating current signal is applied, and another set of data for another spectrum, representative of the ion spectrum when the alternating current signal is not applied. These two spectra can then be subtracted.

Rapid and efficient fragmentation of ions in an ion trap for MS/MS analysis is achieved by a pulsed fragmentation technique. Ions of interest are placed at an elevated value of Q and subjected to a relatively high amplitude, short-duration resonance excitation pulse to cause the ions to undergo collision-induced fragmentation. The Q value of the ions of interest is then rapidly reduced, thereby decreasing the low-mass cutoff and allowing retention and subsequent analysis of low-mass ion fragments.

Tunable down-hole stimulation arrays feature closed-loop control of spatial arrays comprising several connected stimulators. Each stimulator is responsive to a timed activation signal. Stimulators periodically transmit bursts comprising a plurality of vibration frequencies, each burst having an adjustable power spectral density (PSD) that is tunable via an adjustable rebound cycle time. Rebound cycle times also affect vibration interference among array stimulators, while simultaneous or sequential timed activation signals from a programmable controller affect directional propagation of combined vibration wave fronts from an array. Stimulator PSD's are adjusted for resonance excitation and fracturing of adjacent geologic materials. Closed-loop feedback control incorporates backscatter vibration from stimulated geologic material. As fracturing proceeds to smaller (proppant-sized) fragments having higher resonant frequencies, PSD's are up-shifted, increasing relative power in higher vibration frequencies. Progressive geologic stimulation is optimized, with inherent potential for plain-water fracs completed with self-generated proppant.

In a method magnetic resonance apparatus for the determination of k-space positions for modeling of RF pulses for magnetic resonance excitations, the following steps are implemented:

• • (a) select a target magnetization,
  • (b) select a first achievable magnetization as a current achievable magnetization,
  • (c) determine a deviation of the current achievable magnetization from the target magnetization,
  • (d) determine the spectrum of the deviation in k-space as a current spectrum,
  • (e) localize at least one maximum in the current spectrum,
  • (f) store the k-space positions of the localized maxima in a set of previously determined k-space positions,
  • (g) determine current pulse coefficients with which an optimal, current magnetization can be achieved using at least one k-space position from the set of previously determined k-space positions, and
  • (h) repeat (c) through (g) until a predeterminable termination criterion is satisfied (however at least once), wherein in each repetition at least one k-space position is used in the determination of current pulse coefficients that was used in none of the preceding determinations of current pulse coefficients.

A method for mapping field inhomogeneity for forming a magnetic resonance image is provided. A magnetic resonance excitation is applied. A plurality of k-space echoes signals is acquired. A periodic cost function is calculated from the acquired plurality of k-space echo signals. A period of the calculated periodic cost function is divided into multiple regions. A search algorithm is used to locate a local minimum in each region. Located local minimums are chosen to provide global smoothness.