371 results about "Transmission electron microscopy" patented technology

The invention relates to the technical field of computer science, in particular to a stamping prediction method based on a multi-machine learning model and an automatic compensation device.The stamping prediction method comprises the steps that firstly, a sheet microstructure and material characteristics are obtained through a transmission electron microscope and an atomic probe tomography technology, and then finite element simulation sampling is conducted; a data set is expanded by using an adaptive algorithm, multiple models are constructed and trained to obtain a final springback prediction model, an automatic compensation device is embedded to realize automatic compensation, and the automatic compensation device covers visual parameter input, embedded springback prediction, springback compensation calculation and an automatic control module. Parameters can be visually input, springback can be accurately predicted, a compensation value can be calculated, and the process can be adjusted. The method aims at solving the problems that in the high-strength plate stamping process, due to springback, the size and shape of a part deviate from the design requirement, and a traditional prediction and compensation technology is insufficient in precision and efficiency.

The invention relates to a transmission electron microscope low-temperature sample rod using a flexible structure to transfer heat. The transmission electron microscope low-temperature sample rod comprises a liquid nitrogen Dewar tank; the sample rod comprises a sample rod body with a front-back through hollow cavity, a heat conduction rod and a flexible heat transfer rope, one end of the heat conduction rod extends into the liquid nitrogen Dewar tank, the other end of the heat conduction rod extends into the sample rod body, one end of the flexible heat transfer rope is wound and fixed on the heat conduction rod, and the other end of the flexible heat transfer rope is wound and fixed on the sample rod body. The other end of the sample rod extends to the outer end of the sample rod body; the sample rod head comprises a sample rod fixing outer frame and a sample rod temperature control part, the sample rod fixing outer frame is connected with the outer end of the sample rod body, the sample rod temperature control part is arranged on the sample rod fixing outer frame, the sample rod temperature control part is connected with the flexible heat transfer rope, and a heating element capable of heating a sample to be tested is further arranged on the sample rod temperature control part. Compared with the prior art, efficient heat conduction can be achieved, meanwhile, the thermal stress influence is reduced, and the temperature stability and the sample position stability are improved.

The invention discloses an in-situ TEM (Transmission Electron Microscope) device sample preparation method based on a suspended thinning and parallel carrying technology, which can be used for preparing in-situ TEM samples of semiconductor two-end devices and three-end devices, and mainly solves the problems of unstable ohm contact, nonuniform thinning, low success rate and high time cost in the prior art. According to the invention, an FIB sample preparation technology is adopted, and stable and reliable ohmic contact between a sample electrode and an MEMS chip electrode is ensured through specific-angle sample extraction, suspended thinning, parallel carrying, circuit breaking treatment and an accurate electrode welding process. According to the sample prepared by the invention, the failure state of a device can be observed in real time under a transmission electron microscope, the sample has the advantages of high sample preparation success rate, good repeatability, stable electrical parameters and wide applicable chip variety, and the reliability and repeatability of in-situ TEM test data are remarkably improved.

The invention discloses a method for evaluating the growth performance of mangrove forest seedlings in an estuary high-salinity environment, and the method comprises the steps: constructing an analysis framework in which a dynamic salinity stress system and a multi-dimensional monitoring technology are coupled, and achieving the precise evaluation of the environmental adaptability of the mangrove forest seedlings; the method comprises the following steps: firstly, carrying out sterile germination and matrix domestication on a target estuary provenance, then establishing a three-dimensional stress model containing basic salinity maintenance, sudden salinity impact and tidal cycle fluctuation, and strictly controlling the sudden salinity impact amplitude within 20% of the historical extreme value of the estuary; synchronously acquiring canopy volume and root architecture parameters of the seedlings by adopting a three-dimensional laser scanning technology, and constructing a morphological database in combination with leaf apparent characteristic records; subcellular structure indexes such as cell wall thickening, chloroplast envelope integrity and mitochondrial ridge density are observed and analyzed through a transmission electron microscope, the molecular mechanism of osmotic regulation and energy metabolism is disclosed, and the concentration of suspended solids in the water body, the oxidation-reduction potential of sediments and the functional diversity of microorganisms are synchronously monitored.

The invention relates to a mechanical property simulation method for researching the service life of an aluminum alloy material for a reactor. The simulation method for the life period mechanical property of the aluminum alloy material comprises the following steps: S1, preparing initial, middle and last stage aluminum alloy samples according to a < 27 > Al-< 28 > Si transmutation path of the aluminum alloy material; s2, representing the sample by using a transmission electron microscope, obtaining precipitated particle parameters, calculating a volume fraction f, fitting f and operation time t, and constructing a precipitation evolution model f (t); s3, performing high-energy ion irradiation on the sample, and performing nanoindentation experiment and load-depth curve fitting to obtain nano hardness H; s4, based on the f (t), establishing a relation model of the nano hardness H and the irradiation damage D; and S5, calculating the change quantity of the nano hardness H, converting the change quantity into the change quantity of the yield strength, associating the irradiation damage D with the service time T, and establishing a life period yield strength prediction model. According to the method, the mechanical property of the aluminum alloy in the full service cycle of the research reactor can be accurately evaluated.

The invention discloses a preparation method of a transmission electron microscope sample of a sintered neodymium-iron-boron block material, which comprises the following steps of block sample cutting, mechanical grinding, sample punching, ring sticking, pre-thinning and final thinning, so that the transmission electron microscope sample to be observed is obtained. In addition, the method is simple, feasible, economical and practical, and the sample preparation success rate can be remarkably increased.

The invention discloses a transmission electron microscope sample preparation method for a lunar soil space weathered surface and application, and the method comprises the following steps: pasting target lunar soil particles on a carbon conductive adhesive tape, and enabling the target flat surfaces of the target lunar soil particles to be placed back to the carbon conductive adhesive tape; plating a layer of carbon film on the surface of the target lunar soil particle to obtain a scanning electron microscope sample of the target lunar soil particle; screening out a plurality of target research areas on the carbon film corresponding to the target flat surface; uniformly plating a layer of gold film on the carbon film corresponding to the target lunar soil particle scanning electron microscope sample; deposition operation of a research area protection layer is carried out on the gold film corresponding to the target research area through an electron beam and an ion beam in sequence; and performing slicing operation perpendicular to the target flat surface on the target lunar soil particle scanning electron microscope sample to obtain the target lunar soil particle transmission electron microscope sample. According to the method, lunar soil space weathering characteristics can be truly reserved, and an accurate and reliable sample is provided for lunar soil space weathering research.

The invention discloses preparation of an aqueous zinc ion battery positive electrode material and a detection method of charge reaction of the aqueous zinc ion battery positive electrode material in a metal ion battery, and belongs to the technical field of batteries. The invention provides the preparation method of the vanadium-based positive electrode material, which is simple in process and low in cost. The preparation method of the positive electrode material comprises the following steps: grinding vanadium pentoxide powder; performing ultrasonic treatment with deionized water, adding inorganic salt, sealing, performing water bath heating reaction, and performing centrifugal washing; and then drying or freeze-drying to finally obtain the batched and high-performance positive electrode material. In 8000 times of charging and discharging, the positive electrode material provided by the invention has excellent cycling stability, and the capacity retention rate is as high as 93%. In addition, an in-situ alternating-current impedance technology is used for rapidly detecting the charge transfer process in the battery, and complex and expensive in-situ X-ray diffraction and transmission electron microscope technologies are avoided. The vanadium pentoxide activation process is accurately controlled through the water bath, the process is simple, the cost is low, and the method has good batch production potential and application prospects.

The invention discloses a hollow silicon dioxide particle. The ratio of the hollow area of the hollow silicon dioxide particle to the total area of the particle in a transmission electron microscope photo is 10-96%; the average maximum diameter of the hollow silica particles is 100 nm to 10 [mu] m; a shell layer of the hollow silicon dioxide particle is formed by stacking nano particles, the average diameter of nano convex particles in the shell layer is 4-100 nm, and the ratio of the average diameter of the nano convex particles to the average maximum diameter of the hollow silicon dioxide particle is 1 / 2500-1 / 5. The ratio of the average diameter of the nanometer protruding particles on the surfaces of the hollow silicon dioxide particles to the average maximum diameter of the hollow silicon dioxide particles ranges from 1 / 2500 to 1 / 5, so that the bonding force between the hollow silicon dioxide particles serving as filler and resin is high, the fluidity is good when the hollow silicon dioxide particles are added into the resin, and the hollow silicon dioxide particles are suitable for serving as packaging filler of semiconductor devices.

The invention discloses an ion thinning instrument control method based on a self-adaptive gradient energy reduction algorithm, and belongs to the technical field of transmission electron microscope (TEM) sample preparation. The problem that a traditional ion thinning technology has many limitations is solved, dynamic optimization of parameters such as ion beam energy, beam current density and sample temperature is achieved through the self-adaptive gradient energy reduction algorithm, and the sample preparation efficiency is remarkably improved; by combining multi-modal data acquisition and dynamic gradient optimization, the thinning process can be accurately controlled, and the sample quality is improved; sample damage is effectively avoided by combining a damage constraint mechanism and self-adaptive step length control, and the stability of the preparation process is improved; the method is suitable for various materials through a pre-stored optimization path library, and has wide applicability; therefore, the energy of the ion beam is optimized, the incident angle and the beam density are dynamically adjusted, and the thinning instrument is controlled.

The invention provides a preparation method of an exosome antibody microsphere conjugate, which belongs to the technical field of exosomes, and comprises the following steps: preparing a carboxyl polystyrene microsphere suspension with the particle size of 50 nanometers, and ensuring that the size of the microsphere is stabilized in a range of 50 + / -5 nanometers by optimizing centrifugation and cross-linking conditions. And then coupling the exosome marker antibody with the microspheres, and closing unreacted active groups. A mathematical model is adopted to optimize purification process parameters for purification. A dynamic light scattering and transmission electron microscope is utilized to characterize coupling physics properties, and a conjugate meeting requirements is screened. And finally, obtaining fluffy porous exosome antibody microsphere conjugate freeze-dried powder under the protection of a sucrose solution by adopting a vacuum freeze-drying method. The method solves the technical problems that in an existing exosome microsphere conjugate preparation process, centrifugation and purification parameters are often set according to artificial experience, optimization is difficult to obtain, and the quality of the exosome microsphere conjugate is affected.

The invention provides a medium manganese steel oxygen vacancy defect identification method and device. The method comprises the following steps: obtaining a first oxygen vacancy defect area based on a measurement result of a positron annihilation lifetime spectrum and a Doppler broadening spectrum on a target sample block; aiming at each ultra-thin sample, observing the ultra-thin sample through a high-resolution transmission electron microscope, and collecting a bright field image and a dark field image of the ultra-thin sample; obtaining a second oxygen vacancy defect area based on the bright field image, the dark field image and the first oxygen vacancy defect area; performing electron energy loss spectrum analysis on the second oxygen vacancy defect area, and determining a third oxygen vacancy defect area and corresponding oxygen vacancy defect concentration in the ultrathin sample; and determining each target oxygen vacancy defect region and oxygen vacancy defect concentration of the target medium manganese steel sample according to the third oxygen vacancy defect region and oxygen vacancy defect concentration in each ultrathin sample. According to the invention, information such as position, number, size and distribution pattern of oxygen vacancy defects can be accurately obtained.

The invention provides a preparation method of a transmission electron microscope sample, which comprises the following steps: welding a prepared cross section TEM sample on a carrying net, horizontally placing the carrying net, and forming a first protection layer on the cross section; forming a limiting mark; forming a second protective layer on the first protective layer; after the part, close to the connecting end of the same carrying net, of the cross-section TEM sample is welded together with a nano manipulator, the sample and the carrying net are cut and separated at the connecting position; the nano manipulator is moved to the hovering position, and then the nano manipulator is taken back; overturning the sample table to enable the carrying net to be vertically placed; after adjustment preparation, the other end, opposite to the end connected with the nano manipulator, of the sample is welded to the carrying net; after the sample and the nano manipulator are cut and separated, the nano manipulator is taken back; and inclining the sample table to 52 degrees, and cutting and thinning the sample according to the limiting marks to obtain the required planar TEM sample. The purpose of comprehensively knowing the plane and section structure information of the sample can be achieved.

The invention provides an extracellular vesicle marker separation-free detection method based on nanoparticle enhancement, and belongs to the technical field of detection methods, the method comprises the following steps: preparing gold nanoparticles with the surface modified with a first antibody, the first antibody being used for specific recognition of an extracellular vesicle surface marker; determining the particle size distribution of the gold nanoparticles by adopting a dynamic light scattering method, and determining the surface potentials and surface isoelectric points of the gold nanoparticles by adopting a potentiostat; adopting a transmission electron microscope to characterize the morphology of the screened gold nanoparticles; co-modifying polyethylene glycol molecules on the surfaces of the gold nanoparticles to form an anti-interference layer; mixing the gold nanoparticles with uniform morphology with a sample to be detected; adding a second antibody into the mixed system; distinguishing signals of the binding-state second antibody and the free-state second antibody through fluorescence lifetime analysis; preparing an extracellular vesicle standard substance, and obtaining a standard curve and a system response curve; the optimal detection condition is determined by solving the detection system optimization equation set, and separation-free detection is carried out.

To provide an aluminum alloy sheet excellent in rollability.SOLUTION: 0.05% by mass or more and 0.35% by mass or less of Si, 0.05% by mass or more and 0.50% by mass or less of Fe, 0.01% by mass or more and 0.35% by mass or less of Cu, 0.10% by mass or more and 0.80% by mass or less of Mn, 2.0% by mass or more and 6.0% by mass or less of Mg, 0.01% by mass or more and 0.15% by mass or less of Cr, and a balance of Al and inevitable impurities, in a cross section in a sheet thickness direction, a ratio of an area occupied by central grains is 1.15% or less, and in a sheet thickness Mg2Si region, a number-density ratio obtained by dividing a number-density of precipitates observed with a transmission-type electron microscope by a number-density in a reference aluminum alloy sheet, a Si-amount ratio obtained by dividing a Si content by a reference Si content, and a Mg-amount ratio obtained by dividing a Mg content by a reference Mg content satisfy the following formulas: Number density ratio ≥ 10.929 * Si amount ratio - 15.814 + 2.043 * (Mg amount ratio - 1) SELECTED DRAWING: Figure 5

The invention discloses an application of a cucumber CsAPRR2 gene in regulating and controlling the color of pericarp. The invention relates to the field of plant genetic engineering, and provides application of inhibiting expression and / or activity of CsAPRR2 protein in creation of yellow peel cucumber. CsAPRR2 is knocked out through a CRISPR-Cas9 mediated gene editing technology, all knockout mutation lines show the pericarp yellowing character, a transmission electron microscope (TEM) shows that the chloroplast structure of the CsAPRR2 knockout line is damaged, and it is proved that the CsAPRR2 gene can regulate and control the color of the pericarp of the cucumber. The invention provides a molecular tool and a gene resource for researching a cucumber peel yellowing regulation mechanism and cultivating a new variety.

The present invention discloses the application of the NtIPMD gene in regulating the chlorophyll content of tobacco, and belongs to the field of plant genetic engineering technology. Based on the existing progress in tobacco genetic engineering and the observation and identification of related plant phenotypes, the present invention conducts in-depth research on the NtIPMD gene and finds that it is related to the development of tobacco chloroplasts. The nucleotide sequence of the NtIPMD gene is shown in SEQ ID NO.1. After silencing the gene, the chlorophyll content of the leaves decreases, the growth of the plants slows down, and transmission electron microscopy observation reveals abnormal chloroplast development. The present invention finds that the gene encoding tobacco isopropylmalate dehydrogenase, NtIPMD, plays a key role in regulating the chlorophyll content of tobacco leaves, laying the foundation for clarifying the molecular regulatory mechanism of chlorophyll biosynthesis in tobacco leaves and providing a new precise regulatory gene for regulating the chlorophyll content of tobacco leaves.

The invention provides selenium nanoparticles as well as a preparation method and application thereof, and belongs to the technical field of selenium nanoparticles. Acetone ultrasonic cleaning and chemical polishing pretreatment are performed on a pure titanium substrate to obtain a clean surface, an anodic oxidation method is adopted to prepare a # imgabs0 # nanotube array carrier, and the nano-particles are prepared into selenium nano-particles. The method comprises the following steps: accurately depositing selenium nanoparticles on a carrier by using an electrochemical deposition method, realizing load control by combining an electrochemical kinetics principle, realizing uniform dispersion of the particles by matching an ultrasonic dispersion technology with a particle swarm optimization algorithm, and carrying out centrifugal separation and vacuum drying to obtain a spherical selenium nanoparticle product. And a multi-dimensional quality control detection system of a transmission electron microscope, an X-ray photoelectron spectroscopy and dynamic light scattering is established, so that the technical problems that the particle size distribution is non-uniform and the deposition load is difficult to accurately control in the preparation process of the selenium nanoparticles are solved.

The invention discloses a toughening forming method of a high-performance PEI plate for a high-heat-resistance structural part, and particularly relates to the technical field of high-performance composite material forming. Pre-embedding a PEI toughening layer between thermosetting prepreg layers, and controlling the temperature, the pressure, the pressure maintaining time and the heating rate in the hot pressing process; carrying out infrared spectrum or solid nuclear magnetic resonance testing on the interface area sample subjected to hot press molding, and calculating the chain segment residual rate Rp; determining the interface penetration depth Di through a transmission electron microscope in combination with energy spectrum analysis; inputting the Rp and the Di into an interface coupling model, and outputting an interface combination quality factor Q by the model in a form of combining weighted linearity and logarithmic functions; the interface bonding grade is judged according to the Q value, and when the Q value is lower than a threshold value, hot-pressing process parameters are backtracked for optimization; according to the method, quantitative evaluation of the interface performance and process closed-loop optimization are realized, and the interface bonding strength and service reliability of the composite material can be effectively improved.

To provide a group of polyorganosiloxane-containing polymer particles that yield molded articles with excellent impact strength. [Solution] A polyorganosiloxane-containing polymer particle group according to one aspect of the present invention comprises a polymer (A) containing a polyorganosiloxane (A1) and a first vinyl polymer (A2), and a second vinyl polymer (B). When the cross-section of a resin piece obtained by dispersing the polyorganosiloxane-containing polymer particle group in a resin is observed with a transmission electron microscope, the ratio of the number of particles satisfying the following formula (1) is less than 60%, where L is the diameter of each particle in the polyorganosiloxane-containing polymer particle group and M is the maximum domain length of the polyorganosiloxane (A1). M / L>0.1 ···(1)

The invention discloses application of an SlBTA2 gene in regulation and control of development of a tomato fruit cuticle, the nucleotide sequence of the SlBTA2 gene is shown as SEQ ID NO: 1, and the SlBTA2 gene can maintain normal development of the tomato fruit cuticle. It is found that compared with WT, slbta2 mutant fruits are accelerated in water loss after being picked under the room temperature condition; a scanning electron microscope and a transmission electron microscope are used for observation and analysis, and the results show that fruit cuticle synthesis is affected by SlBTA2 function loss, and the thickness of the tomato fruit cuticle is greatly reduced. Therefore, the invention provides a new theoretical basis and a new gene resource for quality maintenance and storage resistance improvement of the picked tomato fruits.

The application discloses a device and method for bending and deforming micro-nano samples in-situ in an electron microscope, and belongs to the field of scanning / transmission electron microscope accessories and micro-nano material mechanical property measurement research. The device comprises four parts, namely a supporting part, a driving part, a bending loading part and a sample stage part. One end of the nano material is fixed to a suspended part at the front end of the sample stage, and the other end is a free end. The free end of the nano material is pushed by the bending loading part driven by the heating and bending bimetallic strip, so that the nano material achieves the bending and deformation effect. The application separates and fixes the bimetallic strip and the sample, solves the problems of poor mechanical stability and easy movement of the sample in the deformation process of the in-situ bending nano material, improves the stability of the fixed sample and in-situ imaging, realizes the bending and deformation of the sample, and simultaneously observes the structural evolution of the material in the deformation process. While realizing the bending and deformation of single / multiple nano wire shafts, the structural evolution of the material in the deformation process is observed in-situ.

This invention relates to a method for locating characteristic defects in cadmium zinc telluride (CZT) samples and a method for preparing CZT samples. The location method includes the following steps: determining the positions of internal feature points on the sample under an infrared transmission microscope; establishing marking features on the sample surface using FIB-SEM; and determining the relative position of the internal feature points projected onto the sample surface by establishing a geometric relationship between the virtual position of the internal feature points projected onto the sample surface and the marking features. The preparation method uses these relative positions to prepare CZT samples. The location method of this invention can simply and effectively establish the positional relationship between internal feature points and surface features, accurately locating internal defect features in CZT samples. This allows for convenient and rapid determination of the specific location for preparing transmission electron microscopy (TEM) samples, thus improving the quality of TEM samples.

This invention provides a rapid preparation method for steel samples for transmission electron microscopy (TEM), relating to the field of physical analysis of steel materials. It is applied to the preparation of various steel samples, including heat-sensitive steels, using a composite binder of cellulose acetate, acetone, silica, and alumina. The binder is used to adhere one side of a wire-cut steel sample sheet to the sheet fixing surface of a grinding aid. A grinding aid area, parallel to the bottom surface of the sheet fixing surface, is provided on the grinding aid device. The grinding aid area is pressed, and sandpaper with progressively increasing grit is used to grind one side until a first preset thickness is reached. Then, the other side is switched, and sandpaper with progressively increasing grit is used to grind the second side until a second preset thickness is reached. The ground sheet is removed, thinned, punched, and electropolished to obtain the target steel sample. This invention can rapidly prepare steel sample sheets with a thickness of 30-50 µm, and the method is simple and has a high success rate.

A method for analyzing a sample using an electron microscope includes: generating ions, molecules, or other particles, such as droplets, from a target sample; introducing the ions, molecules, or other particles into a vacuum cavity of a transmission electron microscope (TEM) in a direction intersecting the path of a pulsed electron beam; recording an electron diffraction pattern associated with the ions through which the pulse passes at each pulse of the electron beam; and calculating the three-dimensional (3D) structure of the ion species based on the recorded electron diffraction pattern.

The invention relates to the technical field of in-situ detection of electron microscopes, in particular to a one-stop four-dimensional transmission scanning focused ion beam double-beam electron microscope, which comprises a vacuum cavity provided with a vacuum cavity cover; a sample table is arranged on the inner side of the vacuum cavity cover; the electron beam, the ion beam, the manipulator, the sample holder and the gas injection system are mounted on the vacuum cavity through the multifunctional in-situ sealing flange; the system further comprises a 4D STEM detector. According to the invention, electron beam observation, ion beam processing, four-dimensional scanning transmission electron microscope imaging information acquisition and in-situ electric, optical, thermal, force and other external field loading functions are integrated, and scanning electron microscope imaging, transmission electron microscope sample preparation and in-situ 4D STEM diffraction information acquisition under multi-field combined application can be carried out on a sample in one device. One-stop full-scale multi-field combined application detection is realized, the test result is prevented from being influenced by contact with air, water and other external environments in the sample transfer process, and meanwhile, the test efficiency is remarkably improved.

The present invention relates to the field of image recognition, and proposes a transmission electron microscopy identification method and system for the separation process of exosomes in gastric cancer tumor tissues. By using a clustering algorithm to divide the suspected structures in the target lens image, a primary evaluation of the exosome manifestation degree at the edge is carried out based on the edge differentiation degree and the degree of darkness outside the edge of the suspected structure. Then, a secondary evaluation is combined with the background staining change state of the suspected structure, avoiding the influence that the contour of the background impurities is relatively deep in the prior art, resulting in low differentiation between impurities and exosomes, and improving the accuracy of identification. Furthermore, the morphological matching degree of exosomes is calculated according to the internal depression characteristics of the suspected structure, avoiding the problem that the accuracy of the identification result is affected by the difference in the facing situation of different structures in the lens image and the observation perspective, and realizing the auxiliary analysis of the depression characteristics of exosomes under different facing situations of the perspective. The present invention improves the accuracy of transmission electron microscopy identification in the separation process of exosomes in gastric cancer tumor tissues.

A multilayer ceramic capacitor includes dielectric ceramic layers and inner electrode layers. The dielectric ceramic layers include crystal grains including a perovskite oxide including at least one A-site element and at least one B-site element. When a cross-section of the dielectric ceramic layers is observed using a scanning transmission electron microscope, the dielectric ceramic layers include grains, on which a plane of a perovskite structure is observed, as crystal grains. The grains, when subjected to compositional analysis by energy dispersive x-ray spectroscopy, have an atom-distributed region in which a concentration of the A-site element or B-site element (c) subtracted from a maximum concentration of the element (cmax) (Δc=cmax−c) is about 2 atm % or less, at one or more atomic sites in the grains, and an area of the atom-distributed region (SΔc≤2%) is about 0.050 nm2 or less.

This invention discloses a measurement technique for the width of magnetic domain walls based on a transmission Lorentz electron microscope, comprising the following steps: (1) observing the sample in a transmission electron microscope and obtaining a series of defocus images corresponding to the magnetic domain walls; (2) replacing the sample with a standard sample, obtaining a series of defocus images, and calculating the correction coefficients for magnifications corresponding to different defocus amounts under the current Lorentz imaging mode; (3) selecting a portion of the magnetic domain walls perpendicular to a certain area in a series of defocus images, performing Gaussian linear fitting on the intensity distribution of this area and correcting it to obtain the transverse width of the magnetic domain walls, and then performing linear fitting based on the relationship between the transverse width of the magnetic domain walls and the defocus amount to extrapolate the intrinsic width of the magnetic domain walls; (4) constructing the magnetization distribution of the magnetic domain walls based on the intrinsic width of the magnetic domain walls, simulating a series of Fresnel defocus images of the magnetic domain walls, calculating the correspondence between the width of the magnetic domain walls and the defocus amount, and extrapolating to obtain the width of the simulated magnetic domain walls under positive focus conditions. Using the method of this invention, quantitative measurement of the width of magnetic domain walls in magnetic materials can be achieved.

A negative electrode active substance layer of a negative electrode for nonaqueous electrolyte secondary battery herein disclosed includes at least a first negative electrode active substance and a second negative electrode active substance. The first negative electrode active substance is configured with an aggregated body of a scaly graphite whose surface of at least one part is covered with a low crystalline carbon. A graphite interlayer distance of the low crystalline carbon is equal to or more than 3.8 Å and not more than 5.0 Å. The second negative electrode active substance is a natural graphite or an artificial graphite whose graphite interlayer distance based on electron diffraction images by the transmission electron microscope is equal to or more than 3.35 Å and not more than 3.4 Å. Here, a mass ratio of the first negative electrode active substance and the second negative electrode active substance is 50:50 to 90:10.