33 results about "High resolution nmr" patented technology

Enhanced nuclear polarization of a magnetic resonance sample provides greater detection sensitivity over conventional NMR spectroscopy due to a method and an apparatus of increasing the detection sensitivity. Molecules capable of forming photo-excited triplet states are combined in a solution with a NMR sample. While in a uniform magnetic field the solution is frozen, optical radiation is applied to produce photo-excited triplet states molecules and a microwave radiation is applied to stimulate transitions of one of the triplet lines producing dynamic polarization of the nuclei in the magnetic resonance sample. The frozen sample is then rapidly melted and a NMR analysis is performed.

The present invention concerns an apparatus (1′) for NMR spectroscopy and/or NMR imaging of a sample. The apparatus comprises a static probe comprising an outer coil for excitation of nuclei of the sample by generating an incident radio frequency field at the Larmor frequency of the nuclei, and for reception of a return radio frequency field emitted by the sample, and a sensitive inner coil (6a′) which is mounted closely around or in contact with the sample container and which is wirelessly coupled to the outer coil by an electromagnetic radio frequency field. The sensitive inner coil is embedded in an inner spinning rotor (2) which is rotatively mounted inside the static probe and which is integral with the sample container, so that the filling factor and the radio frequency field amplitude in the sensitive coil are maximized.

A method and apparatus for treating a sample for acquiring high-definition magnetic resonance images (MRI images) or high resolution nuclear magnetic resonance (NMR) spectra even in the presence of magnetic field distortions within one or multiple scans. The spatial nature and temporal dependence of the field inhomogeneities are determined a priori using any of several literature procedures. A static or oscillating magnetic field gradient is applied on the sample so as to endow spins at different positions within the sample with different resonance frequencies. A phase- and amplitude-modulated radiofrequency (RF) pulse is applied in unison with the magnetic field gradient so as to endow spins at different positions within the sample with a homogeneous excitation/inversion profile. The nature of the spatially-selective RF irradiation is tailored in such a way that, when added on top of the effects of the inhomogeneities, the spins' evolution phases and their signal amplitudes at the time of the acquisition become independent of the inhomogeneities. The spin signals thus created are captured and decoded, so as to obtain the spins' response as if the inhomogeneity was not present. The collected data is processed to a suitable rearrangement and Fourier analysis procedure to retrieve a final undistorted image or spectrum. The magnetic field gradient can be oscillated to impose this kind of inhomogeneity corrections on multiple spatial dimensions sequentially, or simultaneously.

A high resolution NMR probe having two or more resonators, an inner resonator which is closely coupled to a sample and is used to stimulate and receive a response from one nuclear species, and an outer resonator to induce transitions in another nuclear species, wherein the resonators may be provided with cooling capability and may be made of superconducting material, and wherein the inner resonator may be a saddle coil or a birdcage coil with capability of being tuned, and wherein the outer resonator may be one or more spiral wound saddle coil.

A high-resolution NMR probe is offered which is simple in structure and can be fabricated at low cost. The inside of the probe is maintained in a vacuum to adiabatically isolate the inside from the outside. Liquid helium is sent into a first heat exchanger located immediately close to a measurement portion via the innermost region of a triple tube placed in the vacuum. The helium is evaporated in the exchanger to cool a transmit-receive coil and a variable capacitor. The evaporated helium gas is returned via the outermost region of the triple tube. At this time, a radiation shield placed in the vacuum is cooled by a second heat exchanger placed in the return path.

The invention provides a method for obtaining a high-resolution three-dimensional NMR spectrum under a non-uniform magnetic field, and relates to nuclear magnetic resonance spectrometers. The method comprises the steps that (1) a one-dimensional spectrum is sampled by using a conventional one-dimensional pulse sequence and used for analyzing the condition of the non-uniformity of the magnetic field to obtain the line width of a spectral line and provide a basis for experimental spectral width parameter settings; (2) a precompiled intermolecular zero-quantum-coherence three-dimensional spectrum pulse sequence is guided into a nuclear magnetic resonance spectrometer; (3) an intermolecular zero-quantum-coherence signal selection module, an indirect dimension evolution period t1 module, an indirect dimension evolution period t2 module, an indirect dimension evolution period t3 module and a signal sampling period t4 module of the intermolecular zero-quantum-coherence three-dimensional spectrum pulse sequence are opened, and experiment parameters of all the modules of the pulse sequence are set; (4) the intermolecular zero-quantum-coherence three-dimensional spectrum pulse sequence in the step (3) after experimental parameter setting is executed, and data sampling is performed; (5) after data sampling is completed, relevant data post-processing is performed, so that the high-resolution three-dimensional NMR spectrum free of influence by the non-uniform magnetic field is obtained.

A method and apparatus for improving spectral resolution of an NMR measurement in the presence of an inhomogeneous magnetic field. According to one embodiment, a method producing a high resolution nuclear magnetic resonance (NMR) spectrum for a sample in an inhomogeneous magnetic field may comprise generating a first magnetic pulse and a second magnetic pulse, the first and second magnetic pulses being separated in time by a first time period, during the first time period, generating a gradient pulse, repeating the steps of generating the first and second magnetic pulses and generating the gradient pulse N times for different values of a field strength of the gradient pulse, wherein N is an integer greater than one, after each second magnetic pulse, acquiring a signal from the sample, and producing a reconstructed high resolution NMR spectrum from the acquired signals.

A method for obtaining high-resolution NMR (nuclear magnetic resonance) spectra in an inhomogeneous magnetic field relates to a NMR spectrum. The method includes the steps: applying a radio frequency pulse to rotate a magnetization vector from an axis X to a plane XY; evolving while applying coherent gradient in a certain direction; applying a reunion pulse after the evolving is over to acquiring magnetic resonance signals; determining applying manner, intensity and direction of the coherent gradient, the method of which is that a half width LW is used to measure the degree of magnetic field inhomogeneity, Nu is taken as the gyromagnetic ratio of a magnetic core, effective test length of a sample is L, and the applying intensity on the gradient is set to be LW/(NuL); increasing and decreasing the intensity of the gradient to obtain corrected magnetic resonance signals; conducting fourier transforming to obtain coherence spectra of the NMR gradient and the inhomogeneous magnetic field; identifying coherent spectrum via the use of pattern recognition algorithms and recording spectral peak distribution map information; correcting the coherent spectrum; cumulatively projecting the corrected spectrum; finally obtaining one-dimensional high-resolution NMR spectra.

An NMR measurement method adapted for measurements on solid mixture samples starts with irradiating a pulse sequence to the sample in order to measure the longitudinal magnetization relaxation times of nuclei possessing homogeneous longitudinal magnetization relaxation times (step 1). After a lapse of a given period of time t, a high-resolution NMR spectrum is acquired by nullifying spin diffusion across the nuclei (step 2). The steps 1 and 2 are repeated while varying the period of time t. The high-resolution NMR spectra are classified according to value of longitudinal magnetization relaxation time by inverse Laplace transform.

An apparatus and method is discussed for characterizing a fluid sample downhole of aliphatic hydrocarbon compounds, aromatic hydrocarbon compound, or connate mud filtrates containing carbon-13 isotopes using an enhanced nuclear magnetic resonance (NMR) signal on a measurement-while-drilling device. To enhance the carbon-13 NMR signal these nuclei are being hyperpolarized. Either the Overhauser Effect (OE) or the Nuclear Overhauser Effect or optical pumping and the Spin Polarization Induced Nuclear Overhauser Effect (SPINOE) can serve as a mechanism for hyperpolarization of the carbon-13 nuclei.

The present invention discloses a sample tube for the magic angle high-speed rotation method used in a solid nuclear magnetic resonance device probe wherein a radio wave irradiation/detection coil is disposed close to a sample and a method of measuring a high resolution nuclear magnetic resonance absorption spectrum using the same. This tube is suitable for solid nuclear magnetic resonance (solid NMR) measurements of minute amounts of sample. The sample tube has a capillary part filled with a sample and non-capillary parts situated at its two ends, and a spinner which can be detachably inserted into at least one of the outer ends of the non-capillary parts. The capillary part and non-capillary parts are made of a ceramic and/or polymer material.

The invention discloses a nuclear magnetic resonance well detecting instrument probe and a nuclear magnetic resonance well detecting instrument, which comprises a magnet assembly, a coil array and a coil switching control circuit. The magnet assembly comprises a magnet and a support rod, wherein the magnet is fixed on the support rod, and the magnet is used for generating a rotating symmetric magnetic field of radial radiation. The coil array comprises a plurality of identical coils, wherein the coil arrays are arranged evenly at the periphery of the magnet assembly along the axial direction.Each coil can excite and receive signals corresponding to sensitive areas of the azimuth angle range, wherein the signals of sensitive areas corresponding to each coil do not overlap. The coil switching control circuit is connected to the coil array and is used to control the switching of the coils in the coil array. By using the nuclear magnetic resonance well detecting instrument probe and a nuclear magnetic resonance well detecting instrument together, high-resolution underground nuclear magnetic resonance scanning imaging can be realized, so that the user can accurately determine the formation information according to the magnetic resonance scanning imaging result, which is beneficial to the exploitation and development of petroleum reserves.

The invention relates to a method and a device for improving spectral resolution measured by NMR under the condition of a non-uniform magnetic field. According to one embodiment, the method used for aiming at a high resolution nuclear magnetic resonance (NMR) spectrum generated by a sample in the non-uniform magnetic field comprises the following steps: generating a first magnetic pulse and a second magnetic pulse, existing a first period of time between the first magnetic pulse and the second magnetic pulse in time, and in the first period of time, generating a gradient pulse; aiming at different values of the magnetic-field intensity of the gradient pulse, repeatedly generating the first magnetic pulse, the second magnetic pulse and N times of steps of the gradient pulse, wherein the N is an integer more than one; and acquiring a signal from the sample after each second magnetic pulse, and generating a reconstructed high resolution NMR spectrum according to the acquired signal.

The invention discloses a nuclear magnetic resonance analysis device with high resolution ratio. The nuclear magnetic resonance analysis device comprises a frequency meter, a radiofrequency oscillator, radiofrequency coils, a modulation receiver, a sample tube, a first magnetic body and a second magnetic body. The radiofrequency coils include rectangular coil units in even number, one long edge of each rectangular coil unit extends to form a first transmission line locating at the axis, and one short edge adjacent to the long edge bends to extend to form a second transmission line. The sample tube is mounted on a rotor adapter which comprises a column with a through hole; an upper fastener and a lower fastener are respectively arranged on the upper end face and the lower end face of the column; each of the upper fastener and the lower fastener consists of a plurality of fastener pieces, the fastener pieces are arranged along the circumference of each end face at intervals, and thus, the through hole for holding the sample tube is reserved at the center of the upper fastener and the lower fastener. A column cap is arranged on the upper portion of the column and positioned on the periphery of the upper fastener. The first magnetic body and the second magnetic body are respectively positioned on two sides of the sample tube. The nuclear magnetic resonance analysis device has high quality factors. High-power excitation and effective radiofrequency magnetic field distribution are realized, while measurement precision and sensitivity are improved greatly. Besides, stability of samples during rotating is improved, and jamming rate during sample feeding is lowered.

Methods and systems for determining location of hydrocarbon in unconventional plays are provided. The methods comprise at least two steps of measuring formation samples as received, as dried and/or as saturated using high resolution NMR, and subsequent processing of the NMR data to determine one of several formation properties or components where the formation property or the component can be used to locate an oil or gas reservoir, complete a well, and/or increase production efficiency. Also, the present methods provide a series of sequential and ordered combination of steps related to the financial evaluation of number of barrels of oil or cubic feet of gas which can be produced at a location.