11 results about "Electron tomography" patented technology

Provided is an electrode catalyst having excellent catalyst activity, which contributes to the low cost of a PEFC. The electrode catalyst includes a hollow carbon carrier having nanopores with a pore diameter of 1 to 20 nm, and a plurality of catalyst particles supported on the carrier. The catalyst particles contain Pt (0 valence), are supported inside and outside the nanopores of the carrier, and in a case where analysis of the particle size distribution of the catalyst particles is performed using a three-dimensional reconstruction image obtained by electron tomography using STEM, the proportion of the catalyst particles supported inside the nanopores is 50% or more, and at least one nanopore having the shape of a continuous communication hole is formed in a cubic image having one side of 20 to 50 nm obtained from the three-dimensional reconstruction image of the catalyst block.

This invention provides an atomic-level electron tomography 3D reconstruction method. Its core is to match the simulated projection of an atomic model with experimental images through iterative optimization. The method first constructs a 3D space based on the sample contour and initializes the atomic model parameters. Then, it acquires experimental images from multiple angles and their imaging parameters. In each iteration, a simulated projection image is generated based on the current atomic model and imaging parameters, and the difference between it and the corresponding experimental image is calculated as the loss value. An optimization algorithm dynamically adjusts atomic parameters (position, size, etc.) and imaging parameters (such as focus distance and aberrations) to minimize the total loss. This process includes intelligent simplification steps, which can merge or delete atoms to optimize model complexity. Finally, using the converged high-precision atomic model, 3D reconstructed images with arbitrary viewpoints and depths can be generated. This method can achieve high-precision atomic-level 3D reconstruction without completely relying on 360-degree scan data, helping to reduce data acquisition costs.

The application discloses a kind of cryo-EM electron tomography label-free point alignment quality evaluation method, belong to cryo-EM electron tomography imaging technical field.The present application takes gold standard point residual as core evaluation index, realize indirect, objective and global judgment to label-free point alignment quality, gold standard point does not participate in the optimization process of label-free point registration, residual is independent external reference index, guarantee the objectivity, independence and globality of evaluation result, avoid the problem that existing evaluation method is interfered by optimization target, cannot be globally measured.The numerical value of residual, distribution characteristics and comparison of similar methods can realize accurate and scientific evaluation of label-free point alignment quality.The present application provides reliable quantitative reference for optimization, improvement and screening of registration alignment method in cryo-EM electron tomography imaging technology, and has wide practical application value.

Provided is a catalyst for electrode that has excellent catalytic activity and that is capable of contributing toward lower PEFC costs. This catalyst for electrode includes: a hollow carbon support having nanopores with a pore diameter of 1 to 20 nm; and a plurality of catalyst particles supported on the support. The catalyst particles are supported both inside and outside the nanopores of the support, are composed of (zerovalent) Pt, and when analysis of the particle size distribution of the catalyst particles is performed using three-dimensional, reconstructed images obtained through STEM-based electron tomography measurement, the percentage of catalyst particles supported inside the nanopores is 50% or more.

A tool and method for screening cryogenic electron microscopy (cryo-EM) sample grids using vacuum ultraviolet (VUV) illumination in two configurations. First configuration directly images cryo-EM grids using bright-field optical microscopy employing VUV wavelengths and specialized VUV optics. Second configuration converts transmitted VUV radiation from the cryo-EM grid to visible or near-UV light with a scintillator positioned by the grid. The resultant luminescent high-resolution shadow image is viewed using more conventional microscope optics. In both configurations, individual micron-scale grid holes are imaged to determine ice thickness and quality from the optical absorption of ultrathin vitrified water layers with a precision of a few nanometers. Longer wavelengths can be used to independently view protein concentration and distribution within the ice layer. This tool greatly increases yield of high-quality grids before cryo-EM analysis and is compatible with Single Particle Analysis (SPA) and other cryo-EM methods including cryo-electron Tomography and microcrystal electron diffraction.

Provided is an electrode catalyst having excellent catalyst activity, which contributes to the low cost of a PEFC. The electrode catalyst includes a hollow carrier having nanopores with a pore diameter of 1 to 20 nm and micropores with a pore diameter of less than 1 nm, and a plurality of catalyst particles supported on the carrier. The catalyst particles are supported inside and outside the mesopores of the carrier, contain Pt (0 valence), and satisfy the condition of formula (S1) {100 x (N10 / N20) ≤ 8.0} in the case where analysis of the particle size distribution of the catalyst particles is performed using a three-dimensional reconstruction image obtained by electron tomography using a STEM. N10 is the number of noble metal particles not in contact with the micropores with a pore diameter of 1 nm or more, and N20 is the number of catalyst particles supported inside the nanopores of the carrier.

The application discloses a quality recovery method and system for a frozen electron tomographic reconstruction image; wherein the method comprises the following steps: acquiring a two-dimensional projection sequence of a frozen electron tomography; performing three-dimensional reconstruction on the two-dimensional projection sequence to obtain a three-dimensional reconstruction image; processing the three-dimensional reconstruction image by using a trained noise generation model to obtain noise; superimposing the noise on the three-dimensional reconstruction image to obtain a noise superimposed image; and inputting the noise superimposed image into a trained image quality recovery model to output an image quality recovered image.

The application discloses a noise estimation method for frozen electronic tomography images. The method is based on image space correlation, extracts smooth image blocks as noise estimation samples, uses principal component analysis method to separate real signals and noise, selects redundant dimension number to estimate noise level, greatly guarantees the accuracy and robustness of noise estimation result. The noise estimation for a single image comprises the following steps: selecting a sufficient number of smooth image blocks as noise estimation samples; separating noise and real signals by using the principal component analysis method; and selecting a suitable redundant dimension number to estimate the noise level.

The present invention relates to a method for generating a tomographic image using a quantum computer and, more specifically, to a method for generating a tomographic image by quantum computing using a specific algorithm having limited conditions. The present invention further emphasizes the robustness and precision of the algorithm, thereby increasing the possible of effective application in the field of electron tomography (ET) in which accurate reconstruction is essential. In addition, by replacing an existing optimization algorithm with a quantum optimization algorithm, the present invention can be applied with great utility in fields related to medical image diagnosis, especially in fields such as breast cancer and cardiovascular diagnosis.

The invention discloses a fault enhancement reconstruction method based on a composite regular optimization model, and belongs to the technical field of tomography reconstruction. According to the method, a composite regularization model is constructed, and comprehensive and accurate modeling of multi-scale and multi-direction geometric features of a complex image is realized; a weight correction preprocessing step with extremely low calculation cost is introduced outside an iteration framework, so that the problem of projection data mismatching caused by an object outside a view field is effectively compensated, and the intensity distortion and artifacts of the edge of a reconstructed image are remarkably inhibited. The whole reconstruction framework is constructed as a separable convex optimization problem, and the original-dual mixed gradient algorithm is adopted for solving, so that any complex internal circulation or matrix inversion is avoided, the calculation efficiency and the numerical stability of the algorithm are ensured, and the large-scale three-dimensional fault reconstruction task can be efficiently processed. The method is particularly suitable for solving the problem of poor reconstruction quality caused by incomplete and low-signal-to-noise-ratio data in applications such as frozen electron tomography.