6 results about "Spin–lattice relaxation" patented technology

According to one embodiment, a polishing pad includes a polishing layer comprising a urethane-based prepolymer and a curing agent, wherein the spin-lattice relaxation time (T1) and spin-spin relaxation time (T2) measured using TD-NMR for the polishing layer satisfy Equations 1 and 2, respectively, and thus can improve the performance of the polishing pad.

A method for relaxation time determination includes delivering a series of radio frequency (RF) pulses in a sequence to a specimen having a magnetic resonance spin system. The pulses are separated by equal time intervals and the sequence has a duration comparable or greater than a spin-lattice relaxation time for the spin system. The method includes receiving a response after each RF pulse in the series. The response includes a free induction decay and spin echoes. The method includes generating a series of single point imaging (SPI) images from each response. Each SPI image of the series corresponds to an RF pulse in the series. The method includes converting SPI images to a spin-spin relaxation map and a spin-lattice relaxation map.

A process for selecting an additive and / or solvent for a colloidal ceramic suspension includes measuring spin lattice T1 relaxation times by nuclear magnetic resonance for a ceramic-solvent pair and an additive-solvent pair, wherein the solvent is selected from a plurality of different solvents, and wherein the additive is selected from a plurality of different additives. The process includes determining a relaxation number for each of the ceramic-solvent pairs and the additive-solvent pairs from the spin lattice T1 relaxation times, wherein a higher relaxation number is indicative of strong affinity between the additive and solvent and between the ceramic and solvent. Additionally, the process includes selecting the additive and the solvent based on the relaxation number having the highest relaxation number for the colloidal ceramic suspension.

The invention relates to a method for determining the copolymerization proportion of fluorinated ethylene propylene by using a quantitative high-resolution solid nuclear magnetic resonance 19F MAS method, and relates to the technical field of fluorine chemical industry. The method mainly comprises the following steps: firstly, completing spectrum peak affiliation of a 19F spectrum of FEP through a one-dimensional high-resolution solid nuclear magnetic resonance 19F MAS experiment, determining characteristic peaks respectively representing FEP copolymerization units tetrafluoroethylene (TFE) and hexafluoropropylene (HFP), and then completing measurement of 19F atomic nucleus spin lattice relaxation time T1 of a series of FEP samples with different melting points, so as to determine key test conditions for quantifying SS NMR 19F MAS. Finally, the FEP copolymerization proportion is calculated, and the scientific relation between the mass fraction of the HFP in the FEP and the melting point of the HFP is determined, so that after the melting point data of the sample is obtained, the mass fraction of the HFP in the sample can be calculated through the linear relation formula of the obtained melting point and the mass fraction of the HFP in the FEP without solid nuclear magnetic characterization, and the calculation accuracy of the mass fraction of the HFP in the sample is improved. Therefore, the characterization efficiency of the indissolvable and infusible perfluorocopolymer in actual scientific research or production can be improved.

Provided are molecular probes for hyperpolarized 15N magnetic resonance spectroscopic imaging (MRSI) and their use for detecting reactive species (e.g., hydrogen peroxide) and imaging of oxidative stress. In particular, 15N-boronobenzyl-4-cyanopyridinium (15N-BBCP) demonstrated highly favorable physicochemical and hyperpolarization properties, including long spin-lattice relaxation time (T1) and distinguishable 15N chemical shift signals, that make it an effective reaction-based sensing probe for non-invasive, real-time detection of H2O2.

The present disclosure describes systems and methods for enhancing spin lattice (T1) relaxation time in a hyperpolarized molecule of interest during a time period between a hyperpolarization procedure and performing a nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) experiment. The systems and methods generally subject the hyperpolarized molecules to a relatively low magnetic field during the hyperpolarization procedure and / or during any purification procedure following the hyperpolarization procedure. At such relatively low magnetic fields, the hyperpolarizable core can exhibit a relatively long T1 relaxation time constant at near physiological pH. The T1 relaxation time may be further enhanced by performing the hyperpolarization procedure and / or the purification procedure in a deuterated water (D2O) solvent and / or in a solution containing a scavenger such as ethylenediamine tetraacetic acid (EDTA). Such systems and methods may result in a long T1 relaxation time such that the hyperpolarized molecules remain significantly polarized during the NMR / MRI experiment.