47 results about "Magnetic analysis" patented technology

The invention provides a method for detecting the water content and fat content in abalone through a low-field nuclear magnetic resonance technology. The method comprises the following first step of collecting samples, the second step of carrying out low-field nuclear magnetic analysis on the sample, the third step of measuring the samples, the fourth step of establishing a model, the fifth step of evaluating the model, and the sixth step of measuring the water content and the fat content of the samples to be detected. By means of the method, the water content and fat content in abalone can be measured at the same time, detection is rapid and accurate and free of the influence of the surface feature of abalone, and abalone is not damaged in the measuring process.

The invention discloses a low field nuclear magnetic resonance-applied frozen beef freshness nondestructive testing method. The low field nuclear magnetic resonance-applied frozen beef freshness nondestructive testing method comprises the following steps of (A) sample collection, (B) sample measurement, (C) sample low field nuclear magnetic analysis, (D) multiple freshness-related index measurement, (E) model establishment, (F) model assessment and (G) measurement of freshness of samples to be detected. By establishing a mathematical predication model reflecting fresh beef moisture content relaxation spectrum information and multiple indexes related to fresh beef freshness to accurately and reliably detect multiple indexes of an unknown fresh beef simultaneously such as thiobarbituric acidreactive substances (TBARS), volatile basic nitrogen (TVB-N) and pH, the low field nuclear magnetic resonance-applied frozen beef freshness nondestructive testing method can help predict the storagetime of the beef and achieve rapid and nondestructive detection and assessment of the freshness of the fresh beef. The low field nuclear magnetic resonance-applied frozen beef freshness nondestructivetesting method is rapid and accurate, avoids influence of beef surface properties, and during measurement, has no damage to the beef.

The invention provides a determination method for the reaction activity order of active hydrogen-containing components and a curing agent in a propellant, wherein the method is applied to the field of nuclear magnetic analysis of spaceflight fuels. The method comprises the following steps: determination of a detection object; preparation of detection samples; selection of detection conditions; implementation of sample detection; and processing of detection data. According to the invention, a mixed uniform system of active hydrogen-containing components and toluene diisocyanate (TDI) in the propellant is taken as the detection object. To prepare the samples, groups are proportioned according to concentrations, grouped and then uniformly mixed; and a proper amount of the samples are selected and placed in a chromatographic bottle. A low-field nuclear magnetic resonance spectrometer is employed, and the detection conditions are selected. The changing curve of spin-spin relaxation time T2 with reaction time is detected, each vertical coordinate of the curve is normalized, and the reaction activity order of each component and TDI is acquired according to the speed of slope changes before the curve tends to be flat. The determination method provided by the invention has the advantages of simple operation, safety in experiments, reduction in cost, reliable experimental data, optimized detection conditions and simplified detection process.

Two centerlines each of which goes through the center of a surface and is parallel to one of the coordinate axes are considered for each surface constituting a cell. If one of the centerlines intersects a boundary, a line which goes through the intersection and is orthogonal to the centerline is approximated as a new boundary. If a boundary intersects with each of the two centerlines, an orthogonal line expressed by each of two lines which is obtained by crossing each of the two centerlines parallel to each different coordinate axis and a boundary is approximated as a new boundary. Thus, the new boundary is expressed by each part of these orthogonal lines toward the centerline from their intersection.

The invention relates to an optimal selection method of a high-temperature superconducting direct-current cable, which comprises the following steps of: establishing an accurate three-dimensional superconducting cable model by using COMSOL, recording the change of a magnetic field at different winding angles in three-dimensional simulation, recording the change of the magnetic field of a current strip superposed with different harmonic components, and calculating the optimal selection of the high-temperature superconducting direct-current cable. And the magnetic induction intensity is decomposed in parallel and vertical directions, and the per unit value and the reference value which are replaced by the average value of the magnetic induction intensity under different conditions are extracted and compared, so that three-dimensional cable electromagnetic analysis under different conditions can be carried out on cables under different conditions, and the rapidness and the accuracy of cable analysis are effectively improved. Meanwhile, influence factors of anisotropy are analyzed, a basis is provided for winding of the superconducting tape, and the application value of the high-temperature superconducting direct-current cable is explored.

The invention relates to a high-precision fusion neutron energy spectrum measuring device and method. The invention aims to solve problems that an existing fusion neutron energy spectrum measuring device and method are only suitable for diagnosis under high neutron yield if a recoil proton magnetic analysis method is adopted, an initial time waveform and a response waveform are difficult to obtain simultaneously and effectively by using the same detection system if a neutron time-of-flight method is adopted, and an initial time waveform and a response waveform are difficult to obtain simultaneously and effectively if different detection systems are adopted; time difference is additionally introduced, so precision of solving flight time broadening, Doppler energy spectrum broadening, fusion plasma temperature characteristics and the like is reduced. The measuring device comprises a hydrogen-rich perovskite scintillator, a photoelectric conversion device, a power supply, an oscilloscope and a computer, a photocathode of the photoelectric conversion device faces the hydrogen-rich perovskite scintillator; an output end of the photoelectric conversion device is connected with an input end of the oscilloscope, and an output end of the oscilloscope is connected with an input end of the computer. The measurement method is carried out by using the high-precision fusion neutron energy spectrum measurement device.