8 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.

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.

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.

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.