16 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 present invention discloses a method for removing mismatches from cryo-electron tomography images, comprising: S1, screening stable matches from a set of cryo-electron tomography image pairs, and extracting motion information between feature points as training samples; S2, inputting the training samples obtained in S1 into a pre-constructed nonlinear regression model, and fitting a recognition function for calculating the correct probability of all matches of the cryo-electron tomography image pairs through training; S3, based on the recognition function obtained through training fitting in S2, calculating the cryo-electron tomography image pairs to obtain an initial matching group; S4, repeating S1, S2, and S3 until an initial matching group for all cryo-electron tomography image pairs is obtained; and S5, based on all initial matching groups, completing the final mismatch removal using the RANSAC algorithm. This method utilizes the motion consistency between electron tomography projection image sequences to remove mismatches, effectively preserving the correct matches between images while improving the accuracy of alignment results.

A method and system for obtaining electron tomography data from a sample includes a) focussing an electron beam at a first location on a surface of the sample, b) tilting the surface of the sample to a tilt angle to the electron beam while maintaining the surface of the sample at the focus of the electron beam, c) detecting the electron beam focussed at the first location on the surface of the sample, d) translating the sample at the tilt angle to move the focus of the electron beam to at least a second location of the surface of the sample, e) detecting the electron beam focussed on at least the second location on the surface of the sample, and repeating steps b) to e) at one or more different tilt angles.

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.

The application discloses a kind of shared parameter's electronic tomography three-dimensional image denoising system, comprising: image block module, position embedding module, local sensitive hash LSH module, feature extraction module and image denoising module;Image block module is used to divide electronic tomography three-dimensional image into the same size block;Position embedding module is used to generate an embedding vector for each block, and generates position coding and adds to corresponding embedding vector;LSH module is used to calculate the similarity between embedding vector, filter embedding vector with lower than set similarity threshold value similarity;Feature extraction module includes LSH module and encoder, and the encoder is used to extract the feature of filtered embedding vector and reduce the resolution of embedding vector;Image denoising module includes LSH module and decoder, and the decoder is used to extract the feature of filtered embedding vector and restore the resolution of embedding vector, realize the denoising of electronic tomography three-dimensional image.

Apparatus and methods for high-angle tilt tomography of a sample in a liquid medium using a transmission electron beam instrument are described.

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.

Method for training an automatic artifact correction model in an electron tomography image of a sample, comprising the steps of: Performing (201) an acquisition of a first set of projection data of a sample using a transmission electron microscope capable of emitting an electron beam towards the sample, for a plurality of inclination angles of the sample relative to the electron beam belonging to a first angular range, Determining (202) a first set of tomographic reconstructions of the sample from the first set of projection data, Determining (203) a second set of degraded tomographic reconstructions of the sample from a subset of the first set of projection data associated with a subset of inclination angles of the first angular range,Train (204) the artifact correction model to correct the second set of degraded tomographic reconstructions in order to obtain the first set of tomographic reconstructions. Figure 2,

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.