CN117848807B

CN117848807B - Directional cutting method for embedded fossil sample and fossil sample analysis method

Info

Publication number: CN117848807B
Application number: CN202410162780.3A
Authority: CN
Inventors: 陈倩; 曹长群; 蔡悦; 阳乐; 方艳
Original assignee: NANJING INST OF GEOLOGY AND PALEONTOLOGY CHINESE ACADEMY OF SCIENCES
Current assignee: NANJING INST OF GEOLOGY AND PALEONTOLOGY CHINESE ACADEMY OF SCIENCES
Priority date: 2024-02-05
Filing date: 2024-02-05
Publication date: 2024-06-21
Anticipated expiration: 2044-02-05
Also published as: CN117848807A

Abstract

The invention discloses a directional cutting method of an embedded fossil sample and a fossil sample analysis method, which comprises the following steps: screening fossil samples to be analyzed; scanning the fossil sample in a high-resolution scanning mode by using the 3D-XRM to obtain high-resolution 3D-XRM data, and determining an ROI (region of interest) in the fossil sample; manufacturing a fossil sample into an embedding block with scale marks on the surface; scanning the embedded block in a low resolution mode by using 3D-XRM to obtain low resolution 3D-XRM data, and determining the relative position of an interested region inside the fossil sample and the scale on the surface of the embedded block based on the low resolution data and the high resolution 3D-XRM data; marking and positioning are carried out on the surface of the embedded block, and directional cutting is carried out on the embedded block, so that a sheet exposing the ROI is obtained; and carrying out subsequent treatment and analysis on the thin sheet exposed with the ROI to obtain an analysis result. The method can quickly and effectively locate the position of the region of interest in the fossil sample, and realizes the combination of 3D-XRM and FIB-SEM.

Description

Directional cutting method for embedded fossil sample and fossil sample analysis method

Technical Field

The invention relates to the technical field of fossil analysis and test, in particular to a directional cutting method for an embedded fossil sample and a fossil sample analysis method.

Background

In recent years, the ultrastructural imaging device provides high and new technical support for the leading-edge research of geology and ancient biology in new times, and greatly promotes the output of a series of important original achievements. A combination of an X-ray microscopy tomography system (3D-XRM) and a focused ion beam scanning electron microscope (FIB-SEM) is beginning to be used to obtain multi-scale, multi-modal information of a sample. How to construct the information co-sharing of accurate positioning between the 3D-XRM and the FIB-SEM is a technical key for realizing nano-micro scale level 'space structure image-component' holographic information.

However, since the resolution scale of the target object has reached the micron level, and the anisotropy of the interior of the paleontological fossil is large, it is very difficult to accurately and rapidly find, locate and expose the region of interest (which may be simply referred to as ROI) in the sample. Unlike rock (mudstone, shale, etc.), relatively homogeneous samples such as pharmaceuticals, or artificially prepared samples, a large number of cut surfaces can be exposed by random cutting of a large number of samples, and then screening and combination testing can be performed on these cut surfaces. The quantity of the ancient fossil samples is small, and sometimes only one or a few blocks of fossil samples are exposed by adopting a random cutting mode, so that the efficiency is low, the loss of the rare samples is increased, the rare samples are even cut, and the test requirement cannot be met at all. In addition, when 3D-XRM and FIB-SEM are combined, the processing capability of the FIB-SEM is very limited, so that the preliminary processing of fossil samples is time-consuming, high in cost and low in efficiency for large-scale structures.

Disclosure of Invention

In view of the above, the present invention is directed to a method for directional cutting of embedded fossil samples and a method for analyzing fossil samples, which are used for solving at least one of the above problems in the prior art.

The aim of the invention is mainly realized by the following technical scheme:

In one aspect, a method for directional cutting of an embedded fossil sample is provided, comprising:

step S1: screening fossil samples to be analyzed;

Step S2: scanning the fossil sample in a high-resolution scanning mode by using the 3D-XRM to obtain high-resolution 3D-XRM data; three-dimensional reconstruction is carried out based on 3D-XRM data to obtain an internal structural image of the fossil sample, and an ROI (region of interest) in the fossil sample is determined;

step S3: manufacturing the fossil sample into an embedding block with scale marks on the surface;

Step S4: using 3D-XRM to rapidly scan the embedded block in a low resolution mode to obtain low resolution 3D-XRM data; the low-resolution data obtained in the step is aligned with the high-resolution 3D-XRM data obtained in the step S2 in three-dimensional image processing software, and the relative position of the region of interest inside the fossil sample and the scale on the surface of the embedding block is determined;

step S5: marking and positioning on the surface of the embedded block based on the determined relative positions of the region of interest inside the fossil sample and the scales on the surface of the embedded block so as to determine a surface to be cut;

Step S6: the embedding block is directionally cut along the surface to be cut by using a cutting machine, and the sheet containing the ROI is obtained.

Further, step S2 includes:

step S21: scanning a target fossil sample with a resolution of 0.5-3 μm by using a 3D-XRM, wherein the scanning time is 3-8 hours, obtaining high-resolution 3D-XRM data, and accurately positioning the ROI based on the high-resolution 3D-XRM data;

Step S22: performing data processing and three-dimensional reconstruction on the high-resolution 3D-XRM data to obtain the volume data of the fossil sample;

step S23: based on the volume data, a three-dimensional visual expression result of the fossil sample is obtained.

Further, step S3 includes the steps of:

Step S31: placing the fossil sample into an embedding mould, adjusting the sample to a preset direction, pouring an embedding agent, so that the fossil sample is wrapped by the embedding agent and bubbles are removed;

Step S32: firstly, yellow light is used for irradiating for 2-4 hours, then ultraviolet light is used for irradiating for 4-6 hours, and after the embedding agent is solidified, the embedding blocks with scales on the surfaces are taken out, so that the fossil sample is directionally embedded.

Further, the embedding mold used in step S31 includes a mold groove formed by downwardly recessing a mold plate, and the mold groove is formed in an elongated strip shape as a whole; the die groove is provided with a groove bottom surface and four groove side surfaces, and scale protrusions are arranged on the groove bottom surface of the die groove and two of the groove side surfaces which are oppositely arranged, so that the surface of an embedding block formed after the embedding agent is solidified is provided with concave scales.

Further, short scale protrusions are arranged at the positions, close to the right angles, of the bottom surface of the groove, and the short scale protrusions at the two sides of the bottom surface of the groove are discontinuous; the scale bulges on the side surfaces of the grooves are long scale bulges which are vertically and longitudinally arranged.

Further, step S4 includes the steps of:

step S41: scanning the embedded block again by using 3D-XRM at the resolution of more than 10 mu m for 25+/-5 minutes to obtain low-resolution 3D-XRM data;

Step S42: and (2) sequentially importing the low-resolution 3D-XRM data and the high-resolution 3D-XRM data obtained in the step (S2) into three-dimensional image processing software, so that two groups of data are aligned, and acquiring the intersection line of the target to-be-cut surface of the embedding block and the surface of the sample, thereby determining the relative position of the region of interest inside the fossil sample and the scale on the surface of the embedding block.

Further, in step S5, a 193nm excimer laser ablation system is used to perform laser etching scribe positioning on two adjacent surfaces of the embedding block, so as to obtain the intersection line.

Further, the step S5 includes:

step S51: placing a 193nm excimer laser ablation system on the first surface of the embedded sample to be subjected to laser etching upwards;

Step S52: opening GeoStar software, and performing optical imaging on the upper surface of the sample by using an optical imaging system;

step S53: determining the positions of points a and b on the embedded sample in the optical photo by utilizing the A, B value obtained in the step S4;

Step S54: setting ab line segment etching parameters by utilizing the positions of the points a and b on the embedding sample in the steps, and operating software to etch to finish etching of the first marking line;

Step S55: taking out the embedded sample, and placing the adjacent second surface upwards into an excimer laser ablation system; and repeating the steps S52-S54 to obtain the position of the point c, and setting the laser etching parameters of the bc line segment to finish etching scribing positioning and finish etching of the second mark line.

Further, in step S6, when the cutting machine is used to perform directional cutting on the embedded block, the embedded block is clamped and fixed by using the cutting clamp; the cutting fixture comprises a base body, a fixed connecting piece, an arc-shaped track, an end head and a chuck; wherein the base body can be connected to a cutter; the fixed connecting piece is in sliding connection with the base body, and after the fixed connecting piece and the base body relatively move in place, the fixed connecting piece and the base body can be fixed; the convex surface of the arc-shaped track is connected with the fixed connecting piece; the end head is movably connected with the concave surface of the arc-shaped track; the chuck is rotationally connected with the end head, and the chuck rotates on the end head through a rotation adjusting piece arranged on the end head.

Further, the seat body comprises a cross beam, a longitudinal beam, a ball head and a sleeve, wherein the cross beam is connected with the longitudinal beam in a penetrating mode, the ball head is connected with the outer side wall of the longitudinal beam, a sleeve hole is formed in the end portion of the sleeve, the ball head penetrates through the sleeve hole and extends into the sleeve, the diameter of the head of the ball head is larger than that of the sleeve hole, the ball head and the ball head can move relatively, and threads are arranged on the outer side wall of the sleeve.

Further, the fixed connection piece comprises side legs and a connection block, wherein the side legs are respectively connected to two sides of the connection block, a sliding table is connected to the side legs, and the sliding table is in sliding connection with the cross beam.

Further, the slip table wears to locate the crossbeam, the slip table includes two, is connected to respectively on the side foot, two the slip table is located respectively the both sides of longeron.

Further, one end of the sliding table is provided with a sliding hole, an abutting screw is connected with the sliding hole in a threaded mode, and the abutting screw can abut against the cross beam in the sliding table.

Further, the side legs are provided with fixing through holes, the fixing through holes are provided with fixing screws, the sliding table is provided with corresponding fixing grooves, and the fixing screws can be connected to the fixing grooves in a threaded mode to fix the side legs with the sliding table.

Further, the top of fixed connection spare is equipped with the top connecting hole, the side of fixed connection spare is equipped with the side screw, the side screw passes through the side screw hole that the fixed connection spare side was seted up wears to establish in the top connecting hole, the orbital bottom of arc is connected with the grafting pole, the grafting pole inserts and establishes in the top connecting hole, the lateral wall of grafting pole seted up with the grafting screw hole that the side screw hole corresponds, the side screw passes the side screw hole can threaded connection to grafting threaded hole.

Further, the bottom of end has the recess, the arc track with the recess block, the side of end is equipped with the hole soon, the hole soon communicate in the recess, the hole soon rotation is connected with first angle regulation pole, first angle regulation pole is located one end in the recess is connected with first gear, the orbital side of arc is equipped with the arc tooth's socket, first gear with the meshing of arc tooth's socket.

On the other hand, the invention also provides a fossil sample analysis method, which uses the above-mentioned fossil sample embedded directional cutting method to conduct directional cutting on the embedded block to obtain a sheet exposing the ROI; and processing and analyzing the ROI-exposed sheet.

Compared with the prior art, the directional cutting method for embedding the fossil sample can quickly, economically and effectively locate the position of the region of interest in the fossil sample through directional embedding and accurate cutting of the sample, and perform three-dimensional analysis on the structure and components in the sample; and the image data of the macroscopic three-dimensional space structure is highly correlated with the fine structure and the component information data of the local layer, so that richer and comprehensive scientific information is obtained. When the fossil embedding block is cut, an improved cutting clamp is adopted, the whole clamp is fixed on the cutting machine after the included angle between the base body and the cutting machine is adjusted, and the position of the fixed connecting piece relative to the base body can be adjusted by moving the fixed connecting piece; the end head slides on the arc-shaped track, so that the rotation angle of the end head relative to the fixed connecting piece can be adjusted, and the angle of the fossil sample can be finely adjusted; the rotary adjusting piece is controlled to rotate the chuck, the chuck rotates on the end head, and the angle of the chuck can be adjusted, so that the angle of the sample is finely adjusted, and the exposure precision of the fossil sample is remarkably improved. In addition, an improved embedding grinding tool is adopted to prepare a fossil embedding block, so that the embedding block is provided with scale marks with specific marks, and the fossil embedding block is convenient to compare with 3D-XRM, so that preparation is made for carrying out surface scribing and positioning on the embedding block in the follow-up process; the prepared embedding block is in a long and thin strip shape, so that the clamping and cutting of a cutting machine are facilitated, the distance between a sample and a lens in the 3D-XRM can be reduced, and the scanning resolution is ensured.

In the invention, the technical schemes can be mutually combined to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, like reference numerals being used to refer to like parts throughout the several views.

FIG. 1A is a 3D-XRM image of embryonated fossils three-dimensional reconstruction;

FIG. 1B is a slice view derived from a three-dimensional reconstructed 3D-XRM image, with nuclei of interest within the dashed box;

FIG. 2A is a schematic diagram of an embedding mold according to an embodiment of the present invention;

FIG. 2B is a schematic cross-sectional view of an embedding mold according to an embodiment of the present invention;

FIG. 3 is a schematic illustration of marking indicia on the surface of an embedded sample in accordance with an embodiment of the present invention;

FIG. 4 is an SEM image of nuclei in embryonic cells after ion beam processing;

FIG. 5A is an SEM image of the nuclear sites after carbon and platinum deposition and labeling;

FIG. 5B is an SEM image of a region of interest after U-grooving;

FIG. 6 is an image of a spatial distribution reconstruction model of elements obtained based on FIB-SEM superimposed on a three-dimensional structure reconstruction model obtained based on FIB-SEM in VGstudioMax software;

FIG. 7 is an image of a FIB-SEM-based spatial distribution model of elements (small field of view) superimposed on a 3D-XRM-based three-dimensional structural model (large field of view) in VGstudioMax software;

FIG. 8 is a schematic view of a first angle configuration of a cutting fixture according to an embodiment of the present invention;

FIG. 9 is a schematic view of a second angular configuration of a cutting fixture in accordance with an embodiment of the present invention;

FIG. 10 is a schematic illustration of a cutting fixture with parts separated in an embodiment of the present invention.

Reference numerals:

100. Embedding glue; 200. a region of interest in the sample; 300. fossil samples; 400. a first mark line; 500. a second mark line;

1. a mold plate; 2. a bottom surface of the groove; 3. a side surface of the long groove; 4. short groove side surfaces; 5. a long scale protrusion; 6. short scale protrusions;

10. a base; 101. a cross beam; 102. a longitudinal beam; 103. ball head; 104. a sleeve;

20. fixing the connecting piece; 201. a side foot; 2011. a fixing through hole; 2022. a set screw; 202. a connecting block; 203. a sliding table; 2031. a slide hole; 2032. abutting the screw; 204. a top connection hole; 205. a side screw; 206. inserting a connecting rod;

30. an arc-shaped track; 301. a first angle adjusting lever;

40. An end head; 401. a second angle adjusting lever;

50. A chuck.

Detailed Description

The following detailed description of the preferred invention is provided in connection with the accompanying drawings, which form a part hereof, and together with the description serve to explain the principles of the invention, and are not intended to limit the scope of the invention.

Example 1

The invention discloses a directional cutting method of an embedded fossil sample, in particular a cross-scale three-dimensional space structure image-component information combination method of an internal structure of the fossil sample, which comprises the following steps:

Step S1: fossil samples to be analyzed are screened using an optical microscope (LM) or a Scanning Electron Microscope (SEM).

Step S2: scanning the selected fossil sample in a high resolution scanning mode by using the 3D-XRM to obtain high resolution 3D-XRM data; and performing three-dimensional reconstruction based on the 3D-XRM data to obtain an internal structural image of the fossil sample, and determining an internal region of interest (ROI) of the fossil sample.

Step S3: and manufacturing the selected fossil sample into an embedding block with scale marks on the surface.

Step S4: using 3D-XRM to rapidly scan the embedded block in a low resolution mode to obtain low resolution 3D-XRM data; and aligning the low-resolution data obtained in the step with the high-resolution 3D-XRM data obtained in the step S2 in three-dimensional image processing software, and determining the relative position of the region of interest inside the fossil sample and the scale on the surface of the embedding block.

Step S6: and directionally cutting the embedding block along the surface to be cut by using a cutting machine to obtain a sheet containing the ROI, and grinding one of the cutting surfaces to obtain the sheet with the ROI exposed.

Specifically, the step S1 includes the following steps:

Step S11: fossil sample screening, wherein the phosphated embryo-like fossil is subjected to acid soaking, and then is subjected to manual screening under a stereo microscope, so that the fossil is separated from insoluble rock residues. If the preservation quality of the fossil sample can be evaluated under a stereoscopic microscope, step S2 may be performed. Otherwise, step S12 is performed.

Step S12: SEM was used for additional screening. Finally, fossil samples with better preservation quality are selected for subsequent experimental analysis.

Specifically, the step S2 includes the steps of:

Step S21: and scanning the target fossil sample in a high-resolution scanning mode by using the 3D-XRM to obtain high-resolution 3D-XRM data, and accurately positioning the ROI based on the high-resolution 3D-XRM data. The high resolution refers to resolution of 0.5-3 mu m, the high resolution scanning time is 3-8 hours, and the high resolution three-dimensional structure data of the fossil sample can be obtained through data processing. Since fossil samples are small, during the experiment, the operating voltage of the X-ray tube is set to 50 kv for optimum image contrast, and a 4X/10X objective is used to select the appropriate exposure time for a single projection, e.g. set to 6 seconds. To mitigate artifacts, LE2 filters are used to filter low energy X-ray wavelengths. In the scanning process, the sample rotates 360 degrees, and the number of projection images acquired by the imaging system is set according to the requirement.

Step S22: and (3) performing data processing (cutting, filtering, denoising and the like) and three-dimensional reconstruction on the high-resolution 3D-XRM data obtained in the step S21 on VGstudioMax software to obtain the volume data of the fossil sample. The volume data is exported in the form of a stack of virtual slice images.

Step S23: based on the obtained fossil sample volume data, the volume data is subjected to segmentation, rendering, color configuration and other necessary processing to obtain three-dimensional visual expression results of the fossil sample, such as mesh files, animations and the like.

In this example, FIG. 1A shows a three-dimensional reconstructed 3D-XRM image of an embryonated fossil sample, revealing that the sample consists of several polyhedral shaped cells. In addition, each cell contains a spherical nucleus, as shown in FIG. 1B, which is a slice derived from a three-dimensional reconstructed 3D-XRM image, each nucleus consisting of two different mineral phases. The grey values of the two mineral phases are obviously different; however, the specific mineral type cannot be distinguished only from the tomographic image data. To obtain the exact composition of these two mineral phases, we selected one nucleus located within one cell as our subject of investigation, the nucleus of interest was located within the dashed box of fig. 1B, and prepared for three-dimensional EDS analysis to obtain spatial distribution information of the elements as well as finer structural data.

The nuclei selected here act as ROIs, and since the nuclei selected are located within the phosphorylated cytoplasm, rather than exposed to the cell surface, direct elemental detection using EDS is not feasible. Thus, the sample needs to be processed to expose the ROI.

Precise exposure of the ROI is a challenging task, in which high resolution 3D-XRM data of the sample as a whole is critical to navigating to accurately locate the ROI. If the observed ROI is less than or equal to 100 μm from the upper surface of the sample, the FIB (focused ion beam) is used for processing, and the exposure and positioning of the ROI are performed. If the observed ROI is at a distance > 100 μm from the upper surface of the sample, then steps S3-E are used for ROI exposure and repositioning.

Specifically, in step S3, the fossil sample is directionally embedded by using an embedding mold with scale protrusions, so as to obtain an embedding block containing the fossil sample, so that the surface of the embedding block is provided with scale marks with recesses, and the method specifically comprises the following steps:

step S31: and (3) selecting an embedding mould with a proper size, placing the fossil sample into the embedding mould, adjusting the sample to a preset direction, pouring an embedding agent, enabling the fossil sample to be wrapped by the embedding agent, and vacuumizing to remove bubbles in the fossil sample. Among them, technovit 7200,000 VLC single-component resin embedding agent is preferably used as the embedding agent. When the sample is adjusted to a predetermined direction, the ideal cross section of the ROI can be determined based on step S2, so that the ideal cross section of the ROI is perpendicular to the long side groove side surface of the mold groove as much as possible when the sample is embedded. The long strip embedding block with scales on the surface is formed after the long strip embedding block is solidified in the mode, wherein the ideal section of the ROI is vertical or approximately vertical to the side face of the long groove of the embedding block, so that the cutting efficiency is improved, and the loss of a sample is reduced. The angle between the ideal cross section of the ROI and the long wall surface of the embedded block is in the angle adjustment range of EXAKT EP and 300 cutters.

The embedding mold used in step S3, as shown in fig. 2A to 2B, includes a mold groove formed by downwardly recessing the mold plate 1, the mold groove being formed in an elongated strip shape as a whole; the die groove is provided with a groove bottom surface 2 and four groove side surfaces, and scale protrusions are arranged on the groove bottom surface 2 of the die groove and two of the groove side surfaces which are oppositely arranged, so that the surface of an embedding block formed after the embedding agent is solidified is provided with concave scales.

In some embodiments, the width of the graduation projections is 100 μm, the height is 20 μm, the distance between two adjacent graduation projections on the bottom surface 2 of the groove is 1mm, and correspondingly, the width of the graduation on the surface of the prepared embedding block is 100 μm, the depth is 50 μm, and the distance between two adjacent graduation marks is 1mm.

In some embodiments, the position of the bottom surface 2 of the groove close to the right angle is provided with short scale protrusions 6, the short scale protrusions 6 on two sides of the bottom surface 2 of the groove are not continuous, the short scale protrusions 6 on two sides of the bottom surface 2 of the groove are disconnected, the scale protrusions on the side surface of the groove are long scale protrusions 5 which are vertically arranged in a through length mode, the length of the long scale protrusions 5 on the side surface of the groove is the same as the groove depth of the groove of the die, namely, the length of the long scale protrusions 5 on the side surface of the groove is the same as the height of the side surface of the groove. If the long scale protrusions 5 on the sides of the groove are interrupted, the sample embedding block cannot be pulled out, so the scale protrusions on the sides of the groove are designed to extend from the bottom to the top. The structural design not only ensures that the scale on the embedded block can be identified on a finer basis, but also can easily separate the embedded block from the embedding mould.

In an alternative embodiment, the number of short scale protrusions 6 is the same as the number of long scale protrusions 5, i.e. the short scale protrusions 6 are in one-to-one correspondence with the long scale protrusions 5 and meet vertically at right angles.

In another alternative embodiment, the number of short scale protrusions 6 is greater than the number of long scale protrusions 5, each long scale protrusion 5 meets a corresponding short scale protrusion 6 vertically at a right angle, for example, one short scale protrusion 6 is arranged between two adjacent long scale protrusions 5, the distance between two adjacent long scale protrusions on the side surface of the groove is twice the distance between two adjacent short scale protrusions on the bottom surface of the groove, and one long scale line is arranged every 2mm on the side wall of the prepared embedding block for easy identification.

In some embodiments, the lengths of the scale protrusions on the bottom surface 2 of the groove from the middle to the two sides are sequentially shortened, that is, the scale protrusion on the bottom surface 2 of the groove is longest, and the longest scale mark on the embedding block is taken as a zero point, so that the zero point of the scale can be conveniently identified.

In some embodiments, the groove sides at the two ends of the length direction of the mold groove are arc surfaces, the groove sides at the two ends of the width direction are vertical planes, and the length of the vertical planes is greater than the arc length of the arc surfaces. It is also understood that there are two long groove sides 3 and two short groove sides 4 in the four groove sides of the mold groove, the long groove sides 3 are two parallel vertical planes, and the short groove sides 4 are two vertically arranged arc surfaces. The embedding blocks are convenient to separate out by arranging the two ends in the length direction as the side faces of the arc-shaped grooves.

In some embodiments, the embedding mold has a plurality of mold grooves, the mold grooves being sized differently to accommodate samples of different sizes. The length directions of the plurality of mold grooves are arranged in parallel, the sizes of the two outermost mold grooves are the largest and the same, and the sizes of the plurality of mold grooves in the middle are smaller than the sizes of the outermost mold grooves, so that the embedding mold can be operated on the test bed in a balanced manner.

In some embodiments, the mold plate 1 is an elliptical plate, the mold groove is located in the middle area of the elliptical mold plate 1, the elliptical outer frame formed by the edge of the mold plate 1 is used for supporting, and can be matched with the light-curing embedding instrument, so that when the embedding mold is placed into the light-curing groove of the light-curing embedding instrument, the bottom is suspended for cooling, and the outer frame plays a supporting role.

In this embodiment, the difference between step S4 and step S2 is that the scan field and the scan speed are different. The scanning of step S2 is for fossil samples, and a high-resolution sample internal structure image can be obtained. Step S4 is to obtain the relative positions of the embedded block scales and the outline of the fossil sample, and the resolution is not high. Such a solution design improves the scanning efficiency. Specifically, step S4 includes the steps of:

Step S41: the embedded block was again rapidly scanned in low resolution mode using 3D-XRM to obtain low resolution 3D-XRM data. Wherein, the low resolution is the resolution of more than 10 μm, and the scanning time is 25+ -5 minutes.

Step S42: sequentially importing the obtained low-resolution 3D-XRM data and the high-resolution 3D-XRM data obtained in the step S2 into three-dimensional image processing software, aligning the two groups of data by utilizing information such as a sample contour and the like, and acquiring intersection lines of a target surface to be cut of an embedding block and the surface of the sample in the three-dimensional image processing software, such as ab and bc line segments in FIG. 3, so as to determine the relative positions of an interested region inside a fossil sample and scales on the surface of the embedding block; fig. 3 shows the positional relationship of the cured embedding glue 100, the region of interest 200 in the sample, the fossils sample 300, and the first marker line 400 and the second marker line 500, wherein the first marker line 400 corresponds to the line segment ab and the second marker line 500 corresponds to the line segment bc. Three pitch values are obtained in three-dimensional image processing software using a metrology tool: A. b, C. Wherein the graduation marks serve as characteristic starting points for easy identification.

In step S5, a 193nm excimer laser ablation system is used to perform laser etching scribing and positioning on two adjacent surfaces of the embedding block according to the position of the intersection line, and a first marking line 400 and a second marking line 500 are obtained through laser etching, wherein the planes of the two marking lines are the surfaces to be cut.

The step S5 specifically includes the following steps:

Step S51: the first surface of the embedded sample to be subjected to laser etching is upward, and the embedded sample is placed in a 193nm excimer laser ablation system, wherein the 193nm excimer laser ablation system adopts RESOlution SE-S155 type.

Step S52: the GeoStar software was opened and the upper surface of the sample was optically imaged using an optical imaging system using a 100X lens.

Step S53: based on the location of the intersection line, using the A, B values obtained in step S4, geoStar software measurements were used to determine the location of points a, b on the embedded sample in the optical photograph.

Step S54: and setting ab line segment etching parameters by utilizing the positions of the points a and b on the embedding sample in the steps, and running software to perform the etching to finish the etching of the first marking line 400. The laser etching parameters are as follows: the diameter of the beam spot is 5-10 mu m, the repetition rate is 100-300Hz, the scanning speed is 0.2mm/s, and the fluence is 16J.cm ².

Step S55: taking out the embedded sample, and placing the adjacent second surface needing laser etching upwards into an excimer laser ablation system. And repeating the steps S52-S54 to obtain the position of the point c, setting the laser etching parameters of the bc line segment to finish etching scribing positioning, finishing etching of the second mark line 500, and determining the surface to be cut based on the intersected first mark line 400 and second mark line 500.

In step S6, after finishing scribing and positioning the surface of the embedding block, determining a surface to be cut, performing directional cutting on the embedding block along the surface to be cut by using a cutting machine to obtain a sheet containing an ROI, and grinding one of the cutting surfaces to obtain a sheet exposing the ROI, which specifically comprises the following steps:

step S61: a EXAKT EP-300 cutter is used to cut directionally along the surface to be cut to expose or approximate the ROI. Specifically, a cutting clamp is used for clamping and fixing an embedded block positioned by an etched scribing line, the angle and the height of the embedded block are adjusted to a proper space position and posture, laser of a EXAKT EP cutting machine is turned on, so that the laser of the cutting machine can approach or basically align to a surface to be cut, after the laser is basically aligned, the laser is further adjusted to a required cutting surface by adjusting the stepping of the cutting machine, the minimum precision of the stepping adjustment is 1 mu m, a EXAKT EP cutting machine is started, and a diamond band saw performs directional cutting along the surface to be cut to obtain a first cutting surface. And continuously adjusting the stepping of the cutting machine, cutting off the bottom of the sample to obtain a second cutting surface parallel to the first cutting surface, and finishing the cutting preparation of the thin sheet containing the ROI, wherein the first cutting surface and the second cutting surface are two surfaces of the thin sheet, and the distance between the two surfaces is the thickness of the thin sheet.

Step S62: after directional cutting is completed to obtain a sheet containing the ROI, grinding the first cutting surface by using EXAKT CS hard tissue grinding machine to obtain a sheet exposing the ROI, which comprises the following steps:

A second cut surface of the ROI-containing sheet was adhered to a slide. The distance of the first cutting plane from the mark lines ab, bc is observed under a microscope. The slide was secured to EXAKT 400,400 CS hard tissue lapping machine. And selecting a proper number of sand paper, such as 300-4000 meshes, and setting the automatic grinding thickness of the grinding disc machine for further grinding, wherein the gradient selection can be realized. And observing the cut surface of the sample under a microscope, and if the ROI is not exposed, repeating the grinding step, and continuing grinding to approach or reach the position of the ROI to obtain a grinding and polishing surface. It should be noted that this process requires frequent observation of the polished cut surface in order to prevent the region of the ROI from being missed due to too fast polishing. If a complete three-dimensional reconstruction of the region of interest sample is desired, it is sometimes desirable to preserve a partial region of the upper surface of the ROI in order to prevent damage to the ROI. If the ROI is located too deep in the sample, the exposure by direct FIB sputtering is time consuming and inefficient, and the directional embedding, cutting and grinding procedures of this embodiment are more efficient.

In step S61, as shown in fig. 8 to 10, the cutting jig used includes a base 10, a fixed connector 20, an arc-shaped rail 30, a tip 40, and a collet 50; wherein, the base 10 can be connected to a cutter, and the cutter can be a EXAKT EP type 300 cutter; the fixed connecting piece 20 is slidably connected with the base body 10, and after the fixed connecting piece 20 and the base body 10 relatively move in place, the fixed connecting piece 20 and the base body can be fixed; the convex surface of the arc-shaped track 30 is connected with the fixed connecting piece 20; the end 40 is movably connected with the concave surface of the arc-shaped track 30; a collet 50 is rotatably connected to the head 40, the collet 50 being rotated on the head 40 by a rotation adjustment member provided on the head 40.

When the fixture is implemented, after the chuck 50 clamps a sample, the whole fixture is fixed on the cutting machine by adjusting the included angle between the ball head 103 and the cutting machine, the included angle between the base body 10 and the z-axis is adjusted to be plus or minus 20 degrees, and the position of the fixed connecting piece 20 relative to the base body 10 can be adjusted by moving the fixed connecting piece 20; the end 40 slides on the arc-shaped track 30, the rotation angle of the end 40 relative to the fixed connecting piece 20 can be adjusted, the included angle between the end 40 of the clamp and the z-axis can be adjusted by plus or minus 25 degrees longitudinally, so that the angle of a fossil sample can be finely adjusted, the rotary adjusting piece is controlled to rotate the clamping head 50, the clamping head 50 rotates on the end 40, the angle of the clamping head 50 can also be adjusted, the clamping head 50 can rotate in the xy plane for 360 degrees, the angle of the sample can be finely adjusted, and the included angle range between the clamp and the z-axis is plus or minus 45 degrees, namely the adjustable range of 90 degrees is summed. The base 10, the fixed connector 20, the end 40 and the chuck 50 are sequentially arranged along the z-axis direction, and the xy plane is perpendicular to the z-axis.

In some embodiments, the seat body 10 includes a cross beam 101, a longitudinal beam 102, a ball head 103, and a sleeve 104, where the cross beam 101 is connected to the longitudinal beam 102 in a penetrating manner, and the cross beam 101 includes two cross beams 101 arranged in parallel, so that the overall structural stability and strength are better; the ball head 103 is connected to the outer side wall of the longitudinal beam 102, a sleeve hole is formed in the end portion of the sleeve 104, the ball head 103 penetrates through the sleeve hole and extends into the sleeve 104, the head diameter of the ball head 103 is larger than that of the sleeve hole, the ball head 103 and the ball head 103 can move relatively, and threads are formed in the outer side wall of the sleeve 104. The sleeve 104 is connected with the corresponding part of the cutting machine, and the ball head 103 can rotate by an angle of plus or minus 20 degrees relative to the sleeve 104 with the z-axis being 0 degrees. The head diameter of the ball 103 is larger than the diameter of the sleeve hole, so that the ball 103 and the sleeve 104 cannot be separated.

In some embodiments, the fixed connector 20 includes a side leg 201 and a connection block 202, the side leg 201 is connected to two sides of the connection block 202, a sliding table 203 is connected to the side leg 201, and the sliding table 203 is slidingly connected to the cross beam 101. The sliding table 203 is arranged to enable the whole connecting block 202 to slide on the cross beam 101, so that the clamping head 50, the end head 40 and the fixed connecting piece 20 can move relative to the base body 10. The fixed connector 20 formed by the side legs 201 and the connecting blocks 202 is in a trapezoid block structure. A fixed connector 20 is provided to connect the base 10 with the head 40 and the collet 50. The sliding table 203 is arranged on the cross beam 101 in a penetrating manner, the sliding table 203 comprises two sliding tables, the two sliding tables are respectively connected to the side legs 201, and the two sliding tables 203 are respectively arranged on two sides of the longitudinal beam 102. One end of the sliding table 203 is provided with a sliding hole 2031, an abutting screw 2032 is connected with the sliding hole 2031 in a threaded manner, and the abutting screw 2032 can abut against the cross beam 101 in the sliding table 203. After the slide table 203 is slid to a predetermined position, the abutting screw 2032 may be rotated, and the abutting bolt may abut against the cross beam 101 in the slide table 203, thereby fixing the slide table 203 to the cross beam 101. The side legs 201 are provided with fixing through holes 2011, the fixing through holes 2011 are provided with fixing screws 2022, the sliding table 203 is provided with corresponding fixing grooves, and the fixing screws 2022 can be connected into the fixing grooves in a threaded mode to fix the side legs 201 with the sliding table 203. The fixing screw 2022 is provided, the fixing screw 2022 can be screwed into the fixing through hole 2011 and the fixing groove, the side leg 201 and the sliding table 203 are connected, and the fixing screw 2022 can be detached.

In some embodiments, the top of the fixed connector 20 is provided with a top connecting hole 204, the side surface of the fixed connector 20 is provided with a side surface screw 205, the side surface screw 205 is inserted into the top connecting hole 204 through a side surface screw hole formed in the side surface of the fixed connector 20, the bottom of the arc track 30 is connected with a plugging rod 206, the plugging rod 206 is inserted into the top connecting hole 204, the side wall of the plugging rod 206 is provided with a plugging screw hole corresponding to the side surface screw hole, and the side surface screw 205 can be connected into the plugging screw hole in a threaded manner through the side surface screw hole. After the plugging rod 206 at the bottom of the arc-shaped track 30 is inserted into the top connecting hole 204 of the fixed connecting piece 20, the side screw 205 is rotated into place, and the side screw 205 is screwed into the plugging threaded hole, so that the plugging rod 206 and the fixed connecting piece 20 can be fixedly connected. The top connecting hole 204 and the side threaded hole are both arranged on the connecting block 202, the top connecting hole 204 is arranged at the top of the connecting block 202, and the side threaded hole is arranged on the side of the connecting block 202.

In some embodiments, the bottom of the end 40 has a groove, the arc track 30 is engaged with the groove, a rotation hole is formed in a side surface of the end 40, the rotation hole is communicated with the groove, a first angle adjusting rod 301 is rotationally connected with the rotation hole, one end of the first angle adjusting rod 301 in the groove is connected with a first gear, an arc tooth slot is formed in a side surface of the arc track 30, and the first gear is meshed with the arc tooth slot. Rotating the first angle adjustment lever 301 causes the first gear to rotate and the head 40 as a whole moves on the arcuate track 30, thereby producing an angular change. The end 40 slides on the arc-shaped track 30, so that the rotation angle of the end 40 relative to the z-axis can be adjusted, and the included angle between the end 40 of the clamp and the z-axis can be longitudinally adjusted by plus or minus 25 degrees, thereby finely adjusting the angle of the fossil sample

In some embodiments, the side of the end 40 opposite to the screw hole is provided with an angle hole, a second angle adjusting rod 401 is arranged in the angle hole, an angle groove is arranged at the top of the end 40, the chuck 50 is rotatably connected in the angle groove, the angle hole is communicated with the angle groove, the second angle adjusting rod 401 is arranged in the angle hole in a penetrating way and extends into the angle groove, a second gear is connected to the end part of the second angle adjusting rod 401, and the second gear is meshed with a toothed ring at the bottom of the chuck 50. The second angle adjusting lever 401 is rotated to drive the second gear to rotate, so that the angle of the chuck 50 can be adjusted, and the chuck 50 can be rotated in the xy plane by 360 degrees, thereby finely adjusting the angle of the fossil sample.

Compared with the prior art, the directional cutting method for embedding the fossil sample has the following beneficial effects:

a) Through directional embedding and accurate cutting to the sample, effectively improve the exposure efficiency of the inside region of interest of fossil sample, improved the data and allied oneself with the precision, help location to the inside region of interest of sample carry out quick comprehensive analysis, can realize that 3D-XRM and FIB-SEM equipment discern sharing to the location information of the inside region of interest of same target object, thereby obtain the inside three-dimensional data information of striding scale (different resolution) -multimode (different data types) of sample, reduce sample processing cost of preparation, reduce the loss of rare sample, improve experimental efficiency simultaneously.

B) The embedding mould with a simple structure is adopted, and the manufactured embedding block is provided with the scale marks with specific marks, so that the scale marks are convenient to compare with the 3D-XRM, and preparation is made for carrying out surface marking and positioning on the embedding block subsequently; the prepared embedding block is in a long and thin strip shape, so that the clamping and cutting of a cutting machine are facilitated, the distance between a sample and a lens in the 3D-XRM can be reduced, and the scanning resolution is ensured; the prepared embedding block can realize fossil sample treatment by adopting a common cutting machine, is convenient to operate and low in cost, and compared with the traditional random polishing, the efficiency is greatly improved.

C) The method comprises the steps of adopting a directional cutting clamp, fixing the whole clamp to a cutting machine after adjusting an included angle between a base and the cutting machine, and adjusting the position of the fixed connecting piece relative to the base by moving the fixed connecting piece; the end head slides on the arc-shaped track, so that the rotation angle of the end head relative to the fixed connecting piece can be adjusted, and the angle of the fossil sample can be finely adjusted; the rotary adjusting piece is controlled to rotate the chuck, the chuck rotates on the end head, and the angle of the chuck can be adjusted, so that the angle of the sample is finely adjusted, and the exposure precision of the fossil sample is remarkably improved.

Example 2

The invention further discloses a fossil sample analysis method, in particular a fossil sample internal structure trans-scale comprehensive analysis method, which comprises the steps of performing directional cutting on an embedded block by using the directional cutting method of the embedded fossil sample in the embodiment 1 to obtain a sheet exposing the ROI; and processing and analyzing the ROI-exposed sheet.

That is, the fossil sample analysis method of the present embodiment includes steps S1 to S6, and further includes the steps of processing and analyzing the ROI-exposed sheet.

The step of processing and analyzing the ROI-exposed sheet includes:

Step S7: the ROI is further exposed or polished.

Step S8: and performing test analysis on the thin sheet exposed with the ROI by using the FIB-SEM, such as secondary electron/back scattering scanning, EBSD/EDS and other two-dimensional/three-dimensional analysis, and importing VGstudioMax software into the obtained FIB-SEM three-dimensional data for three-dimensional reconstruction.

Step S9: and (3) introducing the high-resolution 3D-XRM data into VGstudioMax software containing the FIB-SEM three-dimensional data, and performing data processing and fine alignment to obtain a cross-scale-multi-mode analysis result of the same fossil by combining the two technologies. Wherein, the trans-scale refers to different resolutions or field sizes, and the multi-mode refers to different data types.

Specifically, step S7 uses a focused ion beam carried by a FIB-SEM and Atlas5 software to further expose or polish the ROI, and comprises the following steps:

Step S71: the sheet containing the ROI was glued to a 45 degree pre-tilted aluminum stapling table. One of the two surfaces of the sheet, which is closer to the ROI, is a polished surface, and the other surface is a bonding surface bonded to an aluminum nail table.

Step S72: and (3) placing the aluminum nail table with the thin sheet into a film plating instrument, coating a gold film of 20-100nm on the surface of the thin sheet to enhance the conductivity of the sample, taking out, placing the sample on a FIB-SEM sample holder, and placing the sample in the FIB-SEM.

Step S73: the sample holder/aluminum stage was tilted 45 degrees parallel to the ion beam machining direction and SEM images were taken using Atlas5 software. If the ROI has been exposed, a direct step S76 is performed. If the surface has approached the ROI area, steps S74-F6 are performed sequentially.

Step S74: the sample surface SEM images were initially aligned with the 3D-XRM images. Specifically, the high resolution 3D-XRM data stack from step S2 is imported into Atlas5 software and aligned with the sample surface SEM image by rotating, switching slice images, adjusting image transparency. After alignment the internal position of the ROI in the sample, including the relative position of the ROI and the xy plane, and the depth from the surface, is confirmed by high resolution 3D-XRM images.

Step S75: ion beam cutting is performed on the position corresponding to the internal ROI. The relative position of the ROI in the xy plane in the above step, and the depth from the surface are used as references to determine the position and depth to be sputtered. The voltage beam current of the ion beam was 30kV,65nA. With the progressive exposure of the ROI, it is necessary to reduce the ion beam current for finer processing. The gradient was surface finished using a small ion beam such as 30nA, 15nA, 7nA, 1.5nA, etc. The cut surface of the ion beam cut nuclear position is shown in fig. 4.

Step S76: the SEM data exposing the ROI are realigned with the 3D-XRM data to ultimately determine the three-dimensional reconstruction region of the sample. Specifically, atlas5 software was used for manual alignment of virtual slice data images of ROIs on sample global structure data and SEM images obtained by 3D-XRM. This step is also advantageous for fine data alignment and combination of step S9.

After successful exposure of the ROI, the next step is three-dimensional reconstruction of the structural and elemental composition of the ROI using FIB-SEM.

Specifically, step S8 includes the steps of:

Step S81: FIB-SEM accurately deposits carbon and platinum layers on the selected ROI surface by means of ion beam induced deposition functions, i.e. deposition layers using trimethylboron and methylcyclopentadienyl platinum as organometallic precursors, as shown in fig. 5A. Has the following functions: 1) The deposited layer protects the ROI from damage during subsequent ion beam sputtering. 2) The designed contrast-differentiated reticle is used for auto-focusing of SEM and determining slice thickness in auto-three-dimensional reconstruction. 3) Two asterisk marks were designed for spectral imaging autofocus.

Step S82: after carbon/platinum deposition is completed, a U-shaped trench is cut around the ROI as shown in fig. 5B. The FIB-SEM then automatically performs ion beam sputtering and SEM imaging according to preset parameters. To collect the elemental distribution information of the ROI, the FIB-SEM system invokes EDS to image the elemental composition of the ROI while collecting the SEM images. In order to obtain high quality images and reduce the charging effect, the electron beam working voltage is 1-5kV, and the beam current is 500pA-1nA. In the SEM-EDS analysis process, the working voltage of the electron beam is automatically adjusted to 8-15kV so as to ensure the generation of strong X-ray signals.

In this example, the Ga+ focused ion beam has an operating voltage of 30kV and a beam current of 1.5nA. For each cross section (slice), the SEM collects two sets of image data for Secondary Electron (SE) and backscattered electron (BSE) modes. In this experiment the z-axis resolution was set to 10nm and a total of 2614 slice images were acquired with a reconstructed volume of ROI of approximately 102.4 x 30 x 26.2 μm. EDS (OxfordUltimMax 170,170) performs elemental imaging once every 10 slices, producing 237 elemental imaging maps in total.

Step S83: the result obtained in the above steps is a three-set image stack comprising Secondary Electron (SE), backscattered electron (BSE) images and elemental distribution maps of a series of slices. The image stack may be three-dimensionally reconstructed and analyzed using volumetric data processing software (e.g., VGstudioMax). Since the back-scattered electron images provide superior contrast in reflecting mineral phase differences, the fine three-dimensional structure of the ROI is reconstructed by superimposing the secondary electron images with the back-scattered electrons. This reconstruction may optionally be performed in VGstudioMax. At the same time, the elemental distribution map of the ROI is imported VGstudioMax, and the reconstructed elemental spatial distribution model is superimposed on the three-dimensional structural model (fig. 6).

In the case of local-level (nano-level) component analysis of micrometer-scale and larger-scale objects, it is often difficult to determine the original orientation of the cutting layer in the sample, which is highly likely to cause interpretation bias or misjudgment. In this embodiment, since the ROI represents only a small portion of the nucleus, it is challenging to understand the morphology of the entire nucleus by examining only the structure and composition of the ROI. To solve this problem, the three-dimensional structural model and the three-dimensional element distribution model of the ROI must be integrated into the nuclear 3D-XRM model of a wider field of view and finely aligned. Therefore, the data isolation between the devices is broken, and the macroscopic three-dimensional space structure image data and the local layer composition information data are overlapped and reproduced.

Specifically, step S9 includes the steps of:

Step S91: high resolution 3D-XRM data is imported into VGstudioMax software in the above step.

Step S92: manual calibration is performed based on easily identifiable structural features such as cell wall ravines. This step involves fine alignment of the x, y, z data, and eventually the local cell wall of the ROI with a body resolution of 10nm can be combined with the nuclear model into an embryonic fossils model with a body resolution of 1.3 μm, as shown in fig. 7. The local cell wall and the cell nucleus model of the ROI are small-view high-resolution energy spectrum data, and the integral embryo fossils model is large-view low-resolution 3D-XRM structure data. The analysis result of the same fossil cross-scale (different resolution/visual field size) -multi-mode (different data types) by combining the two technologies is obtained.

Compared with the prior art, the cross-scale comprehensive analysis method for the internal structure of the fossil sample, provided by the embodiment, realizes the combination of the 3D-XRM and the FIB-SEM, and the large-field volume data of the 3D-XRM provides effective navigation, so that the exposure efficiency of the region of interest in the fossil sample is effectively improved through the directional embedding and the accurate cutting of the sample, the data combination precision is improved, the positioning to the region of interest in the sample is facilitated to carry out the rapid comprehensive analysis, the sample processing and preparation cost is reduced, the loss of a rare sample is reduced, and the experimental efficiency is improved. The combined 3D-XRM and FIB-SEM test has the following advantages: firstly, accurately positioning an interested region under large-field data with micron resolution, and realizing efficient experimental operation to obtain key data of the interested region; secondly, for a large-area structure with homogeneity, the whole structure can be reversely deduced by using three-dimensional micro-area data with nanometer resolution, so that the analysis resolution is improved; third, misjudgment and multiple solutions caused by information insufficiency are eliminated.

The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. A method of directional cutting of an embedded fossil sample, comprising:

step S1: screening fossil samples to be analyzed;

Step S6: the embedding block is cut directionally along the surface to be cut using a cutter, resulting in a sheet with the ROI exposed.

2. The method of directional cutting of embedded fossil samples according to claim 1, wherein step S2 comprises:

3. The method of directional cutting of embedded fossil samples according to claim 1, wherein step S3 comprises the steps of:

4. The method of directional cutting of embedded fossil samples according to claim 1, wherein step S4 comprises the steps of:

5. The method of directional cutting of embedded fossil samples according to claim 1, wherein in step S5, laser etched scribe positioning is performed on two adjacent surfaces of the embedded block using 193nm excimer laser ablation system to obtain the intersection line.

6. The method of directional cutting of embedded fossil samples according to claim 5, wherein step S5 includes:

7. The method according to claim 1, wherein in the step S6, the embedded block is held and fixed by a cutting jig when the embedded block is cut in a direction by a cutter;

The cutting fixture comprises a base body, a fixed connecting piece, an arc-shaped track, an end head and a chuck; wherein the base body can be connected to a cutter; the fixed connecting piece is in sliding connection with the base body, and after the fixed connecting piece and the base body relatively move in place, the fixed connecting piece and the base body can be fixed; the convex surface of the arc-shaped track is connected with the fixed connecting piece; the end head is movably connected with the concave surface of the arc-shaped track; the chuck is rotationally connected with the end head, and the chuck rotates on the end head through a rotation adjusting piece arranged on the end head.

8. The method of directional cutting of embedded fossil samples according to claim 7, wherein the base comprises a cross beam, a longitudinal beam, a ball head and a sleeve, the cross beam is connected to the longitudinal beam in a penetrating manner, the ball head is connected to the outer side wall of the longitudinal beam, a sleeve hole is formed in the end portion of the sleeve, the ball head penetrates through the sleeve hole and extends into the sleeve, the head diameter of the ball head is larger than the diameter of the sleeve hole, the ball head and the ball head can move relatively, and threads are formed in the outer side wall of the sleeve.

9. The method of directional cutting of embedded fossil samples according to claim 8, wherein the fixed connection piece comprises side legs and a connection block, the side legs are respectively connected to two sides of the connection block, a sliding table is connected to the side legs, and the sliding table is slidingly connected to the cross beam.

10. A fossil sample analysis method characterized in that the embedded block is subjected to directional cutting using the directional cutting method for embedded fossil sample according to any one of claims 1 to 9 to obtain a ROI-exposed sheet; and processing and analyzing the ROI-exposed sheet.