14 results about "Relaxation rate" patented technology

The invention provides an intelligent temperature control method and system for relieving stress of a glass annealing kiln. The method comprises the following steps: transmitting acoustic surface waves through a distributed sonic sensor to collect stress propagation data in glass, decoupling coupling characteristics of sound velocity and temperature, extracting a relaxation time constant, and generating a stress relaxation rate; performing time difference cross-correlation analysis to construct a stress propagation three-dimensional gradient field, establishing an incidence relation between the relaxation rate and the gradient field, and constructing a mapping strategy of the temperature set value and the relaxation rate according to the incidence relation; generating a dynamic temperature adjusting parameter and converting the dynamic temperature adjusting parameter into a heater power control signal; and dynamically adjusting a stress data feature extraction rule to match a real-time stress state according to the relevance between the gradient field update frequency and the temperature adjustment rate. According to the application, dynamic mutual optimization of the annealing stress elimination efficiency and the kiln temperature setting precision is realized, the glass residual stress is reduced, and the hidden danger of plate explosion is eliminated.

The invention belongs to the technical field of oil and gas reservoir engineering and multiphase seepage dynamic monitoring, relates to a characterization method of seepage behaviors of multiphase fluid in a porous medium, and particularly provides a dynamic construction method of a multiphase displacement capillary pressure-saturation relationship based on nuclear magnetic resonance. Comprising the following steps: S1, acquiring a low-field nuclear magnetic resonance relaxation spectrum of a porous medium in a gas-water two-phase displacement process; s2, determining two-phase fluid interfacial tension, a wetting contact angle and a rock surface relaxation rate; s3, determining the dynamic cut-off relaxation time of the displacement stage; s4, calculating equivalent capillary pressure; the residual water saturation is calculated, and the equivalent capillary pressure is the capillary pressure corresponding to the current displacement stage and is used for constructing a capillary pressure-saturation curve. According to the method, the capillary pressure change in the porous medium can be obtained only through spectral analysis without a centrifugal or mercury injection experiment.

Techniques for resolving a surface roughness effect with a GPU-accelerated NMR simulation include identifying, with a graphics processing unit (GPU), a segmented micro-CT image input as a computational domain; assigning, with the GPU, a plurality of random walkers into pore voxels of the segmented micro-CT image; initiating, with the GPU, a random walk numerical simulation with the plurality of random walkers; moving, with the GPU, each random walker of the plurality of random walkers from a previous position to a new position; determining, with the GPU, the new position of each random walker; and updating, with the GPU, an NMR relaxation rate to resolve a surface roughness effect based on the new position of each random walker.

A method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device, wherein the scale factor refers to the angular velocity scale factor, is calculated by measuring the first-order and second-order approximations of the output signal with respect to the Z-direction magnetic field. Based on the linear relationship between the first-order and second-order approximations and the Y-direction magnetic field and the X-direction magnetic field, the slopes of the first-order and second-order approximations are related to the scale factor and the electron relaxation rate. The method is rational, simple to perform, and applicable to atomic spin inertial measurement devices based on a coupled ensemble of alkali metal electron spins and inert gas nuclear spins. The method can accurately measure the scale factor and electron relaxation rate in real time, providing a foundation for the development of high-precision atomic spin inertial measurement devices.

A method for measuring alkali metal atom equilibrium spin polarizability based on three-axis magnetic field steady-state response comprises the following steps: firstly, adjusting a device to a normal working state, then applying direct-current magnetic fields in x, y, y and z directions, changing the size of the magnetic field in the z direction, fitting the ratio of two outputs of the device with the square of the magnetic field applied in the z direction to obtain the size of the total relaxation rate, and finally measuring the alkali metal atom equilibrium spin polarizability. Obtaining the pressure broadening of the alkali metal air chamber by using the optical depth of the detection light at a low temperature, then changing the power of the detection light at a normal working temperature, establishing a transfer coefficient by using the pressure broadening and a fitting slope, and finally applying a direct-current magnetic field on a y axis and changing the size of the direct-current magnetic field, and fitting the relationship between the output of the device and the By-fit, so as to obtain the alkali metal air chamber. The final balance spin polarizability is obtained by combining the transfer coefficient, the SERF state required by normal work of the system is not damaged, the influence of temperature is avoided, the measurement error is small, and a more accurate measurement means is provided for further optimizing an SERF magnetic field measurement device to improve the sensitivity of the SERF magnetic field measurement device.

The application provides a relaxation and creep performance correlation method, and belongs to the field of new materials and is used for developing new materials by testing related activities. First, a high-temperature relaxation test is carried out to obtain corresponding data of temperature-stress-creep relaxation rate. Second, a high-temperature creep test is carried out to obtain minimum creep rate data. Finally, the third step is data processing, and a correlation model is constructed. The application aims at the shortcomings of long data obtaining time and large sample consumption of existing creep performance data, and proposes to use the characteristics of short stress relaxation test, i.e., more creep information and less sample consumption, to quickly obtain a large amount of stress relaxation performance data, and then combine the correlation method shown in the application to quickly and massively obtain the creep performance, so that the service performance can be evaluated.

A method for measuring the equilibrium spin polarizability of alkali metal atoms based on the steady-state response of a triaxial magnetic field is proposed. First, the device is adjusted to its normal operating state. Then, DC magnetic fields are applied in the x, y, and y, z directions, with the magnitude of the magnetic field in the z direction varied. The ratio of the device outputs in the two applications is fitted with the square of the applied magnetic field in the z direction to obtain the total relaxation rate. Next, the pressure broadening of the alkali metal gas cell is obtained at low temperature using the optical depth of the detection light. Then, at the normal operating temperature, the power of the detection light is varied, and the transfer coefficient is established using the pressure broadening and the fitting slope. Finally, a DC magnetic field is applied along the y-axis with varying magnitude, and the device output is fitted with the B... y‑fit The relationship between these factors, combined with the transfer coefficient, yields the final equilibrium spin polarization. This method does not disrupt the SERF states required for normal system operation, is unaffected by temperature, and has small measurement errors. It provides a more accurate measurement method for further optimizing SERF magnetic field measurement devices to improve their sensitivity.

The invention relates to a multi-physical mechanism coupled stress relaxation local modeling method, which comprises the following steps of: S1, solving a microstructure state variable under a current stress condition through a microstructure evolution equation by taking initial microstructure information and a loading condition as input parameters; s2, on the basis of the updated microstructure state variable, the current plastic relaxation rate is updated in combination with a thermal-mechanical coupling stress relaxation kinetic equation, and the elastic relaxation amount and the relaxation stress under the current relaxation amount are solved; s3, recalculating the next increment step by taking the updated relaxation stress and microstructure information as new input parameters, namely circularly executing the steps S1-S2 until the expected solving time is reached, and outputting microstructure evolution information and time-varying relaxation stress information in the whole relaxation process; the problems that a current prediction model about stress relaxation basically comes from experimental data secondary processing, and relaxation stress prediction of a key structure material serving in complex loading or important occasions is limited are solved.

Exemplary system, method and computer arrangement for determining rotational invariants, fiber orientations, and scalar parameters of fiber tracts (e.g., compartment fractions, which can relate to intra / extra-cellular space volumes; compartment diffusivities; relaxation rates; exchange rates between compartments; characteristics of structural disorder such as axonal beading) from a general diffusion MRI acquisition is described. For example, gradient directions may not necessarily be arranged in so-called shells, and an acquisition may vary spatially. Furthermore, each acquisition can be undersampled in the k-space. A procedure can also be included for receiving information related to the at least one image. Another procedure can be provided for decoupling tissue and protocol parameters based on a singular value decomposition. A further procedure can be provided for grouping singular vectors into multiplets based on symmetries. Still further procedures can be provided for forming rotational invariants and / or for a parameter estimation.

Techniques for resolving a surface roughness effect with a GPU-accelerated NMR simulation include identifying, with a graphics processing unit (GPU), a segmented micro-CT image input as a computational domain; assigning, with the GPU, a plurality of random walkers into pore voxels of the segmented micro-CT image; initiating, with the GPU, a random walk numerical simulation with the plurality of random walkers; moving, with the GPU, each random walker of the plurality of random walkers from a previous position to a new position; determining, with the GPU, the new position of each random walker; and updating, with the GPU, an NMR relaxation rate to resolve a surface roughness effect based on the new position of each random walker.

The invention discloses a method for determining surface relaxation rates of pores with different sizes in rock and application of the method. The method comprises the following steps: S1, obtaining two subsamples of a rock sample, and respectively carrying out high-pressure mercury injection and nuclear magnetic resonance T2 tests; s2, pressurizing the nuclear magnetic sub-sample to saturate a specified fluid, and measuring a nuclear magnetic resonance T2 spectrum after saturation of the nuclear magnetic sub-sample; s3, carrying out centrifugation on the nuclear magnetic subsample in the S2, and measuring a nuclear magnetic resonance T2 spectrum after centrifugation; s4, calculating the volume Vi + 2 of the movable liquid and the T2 logarithmic mean value T2lm of the centrifuged movable liquid; s5, determining an aperture interval and a logarithmic mean diameter Dlm corresponding to centrifugation by using Vi + 2 and the mercury injection aperture distribution curve; s6, calculating the surface relaxation rate of the corresponding aperture interval by using the T2lm and the Dlm; and S7, sequentially increasing the centrifugal rotating speeds, repeating the steps S3 to S6, and calculating the surface relaxation rates of the aperture intervals corresponding to different centrifugal rotating speeds. According to the method, the surface relaxation rates of pores with different sizes in the rock can be determined, so that a pore size distribution curve with higher accuracy is obtained.

This invention discloses a multilayer composite membrane for invisible orthodontic appliances with low stress relaxation rate and its preparation method, belonging to the field of multilayer composite material technology. The membrane adopts a five-layer symmetrical structure, which includes an outer layer, a first relaxation spectrum bridging transition layer, an elastic core layer, a second relaxation spectrum bridging transition layer, and an inner layer. The outer and inner layers are made of rigid thermoplastic polyester material, the elastic core layer is made of medical-grade thermoplastic polyurethane elastomer, and the transition layer is made of a reactive blend of the above two polymers and an isocyanate-based reactive compatibilizer. The transition layer forms a covalent bond network in situ between the layers through reactive co-extrusion, so that the relaxation time spectrum between adjacent layers is continuously bridged, eliminating the additional viscoelastic dissipation caused by the redistribution of interlayer stress, and achieving a stress relaxation rate of no more than 15% in artificial saliva at 37°C for 24 hours.

The application belongs to the technical field of medical materials, and discloses a preparation method of a manganese-based small-molecule magnetic resonance imaging contrast agent and application thereof. The application first prepares a macrocyclic chelating ligand H4L, and then uses the ligand to prepare a manganese-based small-molecule complex MnL 2‑ , with a molecular formula of C 38 H 56 MnN 10 O9 2‑ , which can be used as a magnetic resonance imaging contrast agent. Through detection, the product has very good stability, and through 17 O NMR testing and relaxation rate testing, the hydration condition q=0.78 of the complex is obtained, indicating that the complex has one coordinated water and can provide a monitorable magnetic resonance signal. The obtained relaxation rate is r1=2.255mM ‑1 s ‑1 , indicating that the product has great application value.

This film has a stress relaxation rate of 70% or more, as calculated by Equation 1. [Method for measuring stress relaxation rate] The film is cut into a strip-shaped test piece measuring 10 mm in length and 30 mm in width, with at least one direction of the film defined as the length direction. This strip-shaped test piece is stretched in the length direction using a tension tester at a tensile speed of 200 mm / min in an environment of a temperature of 25°C and a relative humidity of 45%, and elongation is stopped when an elongation rate of 50% is reached. The stress value of the film is continuously measured from the start of stretching to 30 seconds after the stop of elongation. The stress relaxation rate (%) of the film is calculated on the basis of Expression 1 where "A" (N) is the stress value showing the highest stress within the measurement time, and "B" (N) is the stress value at 30 seconds after the stop of elongation. Expression 1: Stress relaxation rate (%) = (A-B) / A×100