Maximum Ball Research Articles

Quantitative characterization of organic and inorganic pores in shale based on FIB-SEM

The pore structures of shale in the Shahejie formation of Dongying depression were quantitatively characterized by FIB-SEM three-dimensional imaging technology. FIB-SEM was used to obtain high-resolution SEM images and through image registration, geometric correction and image segmentation, the organic pores and inorganic pores in the shale were distinguished. The pore space was converted into a structured pore network model via maximal ball method. Then, the pore size distributions and volume contributions of shale organic pores and inorganic pores, and the coordination number of the total pore network model were statistically analyzed via the pore network model. The results showed that due to the low thermal maturity of organic matter in the Shahejie formation, fewer organic pores were observed in the shale samples, and the number of pores was dominated by inorganic pores. Statistical analysis of the pore network model indicated that the studied shale samples considerably included mesopore (size of 2–50 nm) which accounted for 61.1%, but their contribution to the total pore volume was small (4.2%). Macropores (>50 nm) accounted for a relatively small proportion (38.9%) in number, but they provided the main storage space (95.8%) for the shale oil and gas. The volume contribution of pores to the total pore space at a certain bin size is controlled by the combination of pore number and the pore size. The coordination numbers of the two samples were mainly 0 and 1, indicating that the pore connectivity was poor and isolated pores accounted for most part. These results are critical for further reliable petrophysical simulations based on shale digital rocks as well as for the accurate understanding of their petrophysical properties.

Potential use of the medicine ball throw test to reveal the upper-body maximal capacities to produce force, velocity, and power

The aims of this study were (1) to evaluate the shape of the load-velocity (L-V) and force-velocity (F-V) relationships obtained during the medicine ball throw (MBT) test, (2) to explore the reliability of their parameters (L-V parameters: maximal load ( L0), maximal velocity ( V0(L-V)), slope of the L-V relationship ( a(L-V)), and area under the L-V relationship line (Aline); F-V parameters: maximal force ( F0), maximal velocity ( V0(F-V)), slope of the F-V relationship ( a(F-V)), and maximal power ( Pmax)), (3) to explore the concurrent validity of the two-point with respect to the multiple-point method, and (4) to evaluate the external validity of L0 and F0 with respect to the maximal strength. Twelve males performed MBTs against four loads, a bench press 1-repetition maximum (1 RM), and maximal isometric medicine ball push. The L-V and F-V relationships were strongly linear (individual r ≥ 0.886). V0 was the only variable that always showed an acceptable reliability (CV ≤ 3.4%). L0 and F0 presented trivial to moderate correlations with the bench press 1RM and maximal isometric medicine ball push performance. Therefore, the MBT test can be implemented to reveal the maximal velocity capacity of upper-body muscles, but not maximal force or power capacities due to their low reliability and external validity.

Analisis Gerak Shooting Three Point Basket Pada Pemain Klub Dubas Di Kabupaten Magelang

Basketball is a sport game that is played in groups where each group consists of 5 players. This sport is played by getting the ball into the ring as much as possible. One technique to score points is shooting. The shooting that scores the most points is the three-point shooting. The purpose of this research is to analyze the motion of three-point shooting to achieve an effective and efficient movement. The type of research used is descriptive quantitative by analyzing the principles of kinematics in biomechanics. To perform an analysis of the kinematics principle using the kinovea software version 0.9.4. The research sample was the male U-21 athletes of the Dubas club in Magelang Regency, totaling 10 people. The results obtained in this study were the average elbow angle of the preparation phase was 69.30o with an average leg angle of 103.04o. In the release phase, the average shoulder angle produced is 113.52o with an average leg angle of 166.68o. In the follow-through phase, the average elbow angle produced was 170.52o with an average shoulder angle of 134.83o and an average leg angle of 164.27o. The average jump height is 0.54m with an average maximum ball height of 6.05m. The most effective preparatory phase angle is at or close to 90o. The most effective shoulder angle in the release phase is 108o-111o. Jump height affects the effectiveness of three-point shooting.

Biomechanical Analysis of First Serve Tennis

Serve tennis is the most important stroke in the game of tennis to determine the outcome of the match, which is done by means of the ball crossing the net into the opponent's service box diagonally with the desired speed and landing location. This study aims to explain the biomechanical analysis of first serve tennis which produces maximum ball speed. The research method is in the form of quantitative biomechanics with an inferential analysis approach in the form of correlation analysis. Twelve students of the Department of Sports Coaching, Faculty of Sport, made a first serve at the service box, the movements were recorded using a Canon EOS 1100D DSLR camera. The variables analyzed were flexion angle, extension angle, tilt angle, angular velocity, angular acceleration, time, momentum, force, impulse, power, and effort. Pearson Correlation is used to show how big the correlation between ball speed and the studied biomechanics variables. The results showed that there was a large, very large, and perfect correlation on the variables of momentum (r = 1,000), force (r = .663), impulse (r = 1,000), power (r = .844), effort (r = . 982), while the other variables show very small, small, and moderate correlations. So it can be concluded that first serve tennis can be seen as a coordinated and complex movement, involving the development and transfer of momentum, force, impulse, power, and effort to achieve maximum ball speed. This study implies that in doing first serve tennis, it is necessary to pay attention to momentum, force, impulse, power, and effort to produce maximum ball speed.

The Effectiveness of Coaching the Australian Recommended Fundamental Overarm Throwing Skill Criteria for Less-Skilled Adolescents

ABSTRACT Purpose: The aim of this study was to investigate the effects of coaching the Australian recommended fundamental overarm throwing skill criteria for less-skilled adolescents on movement competency using three-dimensional (3D) motion analysis. Methods: Less-skilled non-sports-active and skilled sports-active pupils were assigned to FMS Group (n = 97) and Sports Group (n = 129), respectively. Demographic, anthropometric, whole-body kinematic (discrete and time-series angular displacement and angular velocity data), motor coordination (segmental sequencing) and motor performance (maximum ball release speed) were analyzed. Baseline data were compared using independent T-tests and Chi-Square tests; interaction effects were assessed using repeated-measure ANOVAs. Changes in time-series kinematic data were analyzed by comparing the areas enclosed by the 95% confidence intervals. Results:There was merely a modest improvement in motor competency for the less-skilled pupils. The FMS group significantly acquired 13/75 discrete kinematic variables (p < .01) and four movement patterns but not motor coordination (p = .469) and motor performance (p = .756). Prior to the intervention, the pupils acquired 4/7 recommended skill criteria. The descriptions of another three criteria were not appropriate with no improvement in motor coordination and performance. Two new skills were identified and improved after the FMS intervention. Conclusions: The recommended skill criteria for children were not developmentally and age-appropriate for early adolescents. The use of quantitative 3D motion data provided a more precise and developmentally applicable fundamental overarm throwing criteria than content validated skill criteria. The recommended skill criteria should be modified to facilitate teachers and coaches for effective education.

Impact of Engaging the Nonthrowing Arm on Maximal Ball Velocity From an Overhand Throw With Both the Dominant and Nondominant Arms: A Pilot Study

The overhand throw is a complex whole-body motor skill that is fundamental to many sports and activities. When throwing properly, the momentum generated to complete the movement begins in the lower body and transfers through the trunk to the throwing arm. This proof-of-concept study’s primary purpose was to evaluate the impact of the nonthrowing arm on the ball speed during an overhand throw with both the dominant and nondominant arms. Eighteen participants (age: 20.20 ± 2.90 years, nine women) were divided into two intervention groups: a pulling group taught to engage the nonthrowing arm through a pull toward the body and a nonpulling group taught the overhand throw using a component-based physical education curriculum. Each participant completed 12 total throws, six for each side (dominant and nondominant arm). Ball speed and kinematic data were collected using an eight-camera motion analysis system and were assessed using a pre–post study design. The two groups showed significant improvements pre–post when throwing with both the dominant and nondominant arms. Based on effect size comparisons, engaging the nonthrowing arm makes a meaningful difference in maximal ball velocity.

Effect of support foot placement on football instep kick performance

ABSTRACT Although the support foot plays an important role in kicking a football, there has been a paucity of research exploring the effect of the placement of the support foot on kicking performance. To investigate the kick performance under different support foot positions, ten male footballers were recruited to participate in two experiments: one determining the maximum ball speed and the second determining accuracy. The participants were instructed to plant their support foot on one of nine different spots marked in the form of a 3 × 3 shape on a piece of artificial grass and asked to kick the ball. In the first (maximum speed) test, the participants tried their best to kick the ball at the maximum ball speed from nine different support foot positions. In the second (accuracy) test, the participants kicked the ball toward the target area without restricting the support foot position. The ball speed, as well as the success rate, were recorded from each support foot position. Significantly higher ball speed and accuracy were obtained at medial positions than was the case at lateral positions from the nine spots. It was concluded that although footballers may choose different positions for support foot placement, the maximum ball speed and better accuracy could be expected when the support foot was next to or slightly in front of the ball centre without too much side-by-side separation (27–37 cm).

X-ray Micro CT Based Characterization of Pore-Throat Network for Marine Carbonates from South China Sea

The pore-throat network of rock exerts a vital influence on the permeability and mechanical properties of the rock. Resorting to X-ray micro-CT scanning, the present work investigates the pore-throat structure of marine biogenic carbonate samples from the South China Sea and compares them to terrigenous sedimentary sandstone. With the help of the maximum ball (MB) algorithm, the pore-throat networks inside representative elementary volumes of rock samples are revealed by stick-and-ball diagrams, which enables quantitative analyses afterwards. Higher and more deviant cross sectional porosity was observed for the carbonate samples compared to the sandstone sample, indicating relatively heterogeneous pores in the carbonate. Over 85% of pores in the carbonate samples were classified as mesopores. Irregular triangular cross sections can be inferred for the pores and throats of the carbonate. The type of rock and the porosity seem to have little effect on the shapes of the pores and throats. In the studied carbonate, the average volume of the throat was approximately one order of magnitude smaller than the average volume of a pore. The distribution of throat radius differed significantly between the studied carbonate samples. The average coordination number of the carbonate was measured to be 1.

Physical and technical demands of Australian football: an analysis of maximum ball in play periods

BackgroundThis study compares ball in play (BiP) analyses and both whole game (WG) and quarter averaged data for physical and technical demands of sub-elite Australian football (AF) players competing in the West Australian Football League across playing positions.MethodsMicrosensor data were collected from 33 male AF players in one club over 19 games of the 2019 season. BiP time periods and technical performance data (e.g., kicks) were acquired from the Champion Data timeline of statistics, and time matched to the microsensor data. Linear mixed modelling was utilised to establish differences between maximum BiP periods and averaged data.ResultsThe analyses indicated significant differences (p < 0.0001) between maximum BiP and WG data for all metrics and all playing position (half-line, key position, and midfielders). The percentage difference was greatest for very high-speed running (171–178%), accelerations (136–142%), high-intensity efforts (128–139%), and high-speed running (134–147%) compared to PlayerLoad™ (50–56%) and total running distance (56–59%). No significant (p > 0.05) differences were evident for maximum BiP periods when they were compared between playing positions (i.e., half line vs key position vs midfield). Significant (p < 0.0001) differences were also noted between maximum BiP phases and averaged data across all 4 quarters, for each microsensor metric, and all playing positions. Technical actions (e.g., kicks and handballs) were observed in 21–48% of maximum BiP phases, depending on playing positions and microsensor metric assessed, with kicks and handballs constituting > 50% of all actions performed.ConclusionsThese results show the BiP analysis method provides a more accurate assessment of the physical demands and technical actions performed by AF players, which are underestimated when using averaged data. The data presented in this study may be used to inform the design and monitoring of representative practice, ensuring that athletes are prepared for both the physical and technical demands of the most demanding passages of play.

Quantification of Porous Properties of Shear Crystallized Lipids.

The aim of this study was to investigate the impact that shear and composition have on the structural properties associated with the porous phases of lipids. To accomplish this aim, we developed eight main crystallized samples using cocoa butter (CB) or trilaurin (TL) in the presence or absence of monostearate (M) (5% w/w). The samples were sheared at 500 s−1 using random (RS) or laminar (LS) shear at a cooling rate of 2 °C/min. Using the maximal ball (MB) algorithm, several empirical void measurements such as connectivity (z), pore and throat volume weighted radii (R43), and void fraction (v) were quantified using 3D X-ray microcomputed tomography images. Most void features were identified as micropores (R ≥ 10 μm) possibly originating from the crystallization process and post-process crystal growth. Likewise, depending on the applied treatments, mechanisms impacting void formation were found to produce noticeable variation in v (0.019 to 0.139) and to determine whether void morphology was spherical, irregular, and/or highly connected.

Resistive and propulsive forces in wheelchair racing: a brief review

&lt;abstract&gt; &lt;p&gt;Wheelchair racing is one of the most important sports in the Paralympics. The detailed analysis of all parameters is of great importance to achieve sporting excellence in this modality. In wheelchair racing, resistive and propulsive forces determine the movement of the athlete-wheelchair system. Most of propulsive forces are generated by the strength of individuals. As a result, strength levels play an important role in propelling the athlete-wheelchair system. Thus, the main objective of this study is to provide a set of methodologies to assess propulsive and resistive forces. The manuscript presents different methods and procedures, based on previous studies, that can be used for wheelchair racing athletes. Resistive forces in wheelchair racing can be evaluated by analytical procedures, experimental tests, and numerical simulations. Moreover, the strength of athletes' upper limbs to generate propulsion in wheelchair races can be assessed by dynamometry, one-repetition maximum, and medicine ball throw test. It may be that the tests presented may be useful to predict the strength and endurance of athletes' upper limbs. However, this competitive sport still presents a considerable gap in the Paralympics research. Currently, in Paralympic sport, evidence-based methodologies are lacking, making it an issue for athletes, coaches and researchers to support their work on scientific evidences.&lt;/p&gt; &lt;/abstract&gt;

Quantitative characterization of pore size and structural features in ultra-low permeability reservoirs based on X-ray computed tomography

The pore structure of ultra-low permeability sandstone (0.1 mD < K < 1 mD) is complex and has high heterogeneity, which leads to great challenges in reservoir characterization and effective evaluation. To study the effect of the heterogeneity of ultra-low permeability sandstone on permeability, a digital core model was established using X-ray computer tomography (CT) technology. Then a three-dimensional pore network model (PNM) in core samples was created using the “maximum ball method” algorithm. Finally, the geometric topology features of ultra-low permeability reservoirs were quantitatively characterized. According to the physical properties and test results of samples, the porosity distribution of targeted area ranged between 5.92% and 10.08%, and the permeability distribution range was 0.145 mD–0.75 mD, which was typical for an ultra-low permeability reservoir. The distribution of pore throat radii ranged from 0.27 μm to 1.29 μm, the shape factor was 0.04–0.06, the disconnected pores of the four samples made up between 16.89% and 58.71% of all pores, and the fractal dimension fluctuated between 1.05 and 1.5. Plane porosity also showed certain fractal characteristics. Correlation analysis showed that the disconnected isolated pores and the micron-scale pore throat radii of the reservoir sandstone were the main factors resulting in ultra-low permeability. The above-mentioned quantitative characterization parameters can be subsequently used to conduct microscopic seepage simulation studies of such reservoirs. • Build digital core based on CT scanning system. • Extract the core pore network model, and render the pore pressure, throat flowrate, and electricity conductivity. • A digital core pore structure evaluation method for Utral-low permeability sandstones was developed.

Research on Boundary Layer Effect in Fractured Reservoirs Based on Pore-Scale Models

It is of great significance to study the seepage characteristics of heavy oil reservoirs, which are conducive to the efficient development of resources. Boundary layer effect (BLE) exists in the pore-scale flow process of macromolecular fluid media, which is different from the flow law of conventional fluid in the pore, yet the influence of BLE is ignored in the previous pore-scale simulation. Conventional porous media simulations have difficulty analyzing the mass transfer law of small-scale models under the influence of microfractures. Based on the CT scanning data and thin section data of the real core in the target area, the rock skeleton and flow space were extracted according to the maximum ball algorithm, and the pore network model representing the complex structure was constructed. The microscale effect of macromolecules in the flow process in the pores was characterized by modifying the effective flow. The effects of the BLE on the effective connectivity, displacement process, and oil distribution law were analyzed. The seepage characteristics of different wettability conditions and different water cut stages were compared. The results show that BLE reduces the effective flow space and leads to deviations in the relative permeability curve and capillary curve. For fractured porous media, the irregular shape of porous media was characterized by the morphological method, and the mass transfer process was analyzed by the equivalent flux method. The influence of the porous media shape on the macromass transfer process was compared. This study provides a solution to the problem of BLE in pore-scale simulation.

Motion Analysis Focusing on Rotational Movements of Professional Female Baseball Pitchers: Comparison with Male University Baseball Pitchers.

Purpose: The purpose of this study was to compare pitching motion of the professional female baseball pitchers with the male university baseball pitchers focused on the pelvic and thoracic movements. Subjects and methods: The participants were 15 healthy professional female baseball pitchers (11 right-handers and 4 left-handers; age, 21.7 ± 3.2 years; height, 162.5 ± 5.1 cm; weight, 59.0 ± 6.6 kg) and 14 healthy male university baseball pitchers (12 right-handers and 2 left-handers; age, 19.9 ± 0.8 years; height, 176.4 ± 3.0 cm; body mass, 73.1 ± 3.0 kg). Throwing motion was captured by three-dimensional motion analysis system. Kinematic data of the lead hip, pelvis, thorax, and dominant shoulder were collected and the joint angle at maximum external rotation phase and ball release phase were compared. Results: The female baseball pitchers rotated pelvis and thorax more than the male at the maximum external rotation phase and ball release phase (p < 0.05). At the same, the pelvis and thorax of the female baseball pitchers were tilted significantly closer to horizontal plane than the male (p < 0.05). The pelvis and thorax of the male baseball pitchers was tilted to non-dominant lateral side. Conclusions: The results of this study indicate that the pelvic and thoracic movements of the professional female baseball pitchers was different from male university pitchers.

Golf Learning: 3D Kinematics Approach to Long Drive Swing Shot

The aim of this study is to determine the difference between long drive swing mechanical movement and ball velocity among skilled and unskilled golfers using a 3D kinematics approach. The method used was descriptive quantitative, and the data analysis technique was an assessment of the average test difference. Moreover, the sample was 6 skilled and 6 amateur male player groups, with an average height of 1.67 ± 2.43 m, weight 72.4 ± 86.3 kg, and age 25.4 ± 36.2 years. According to the results, four indicators revealed significant differences among the ten kinematics variables investigated, including club speed at impact (P = 0.038), lateral bend after impact ball (P = 0.041), hip rotation at the top (P = 0.045), and shoulder rotation (P = 0.028). In summary, the long drive swing technique in producing maximum ball speed is dependent on the harmonization of the motion sequence from the lower body to the swing of the stick. Furthermore, the rotational speed of the hip joint at the beginning of the downswin followed by the shoulder angular velocity is a movement characteristic of professional players.

Graph-Based Shape Analysis for Heterogeneous Geometric Datasets: Similarity, Retrieval and Substructure Matching

Practically all existing shape analysis and processing algorithms have been developed for specific geometric representations of 3D models. However, the product development process always involves a large number of often incompatible geometric representations tailored to specific computational tasks that take place during this process. Consequently, a substantial effort has been expended to develop robust geometric data translation and conversion algorithms, but the existing methods have well known limitations.The Maximal Disjoint Ball Decomposition (MDBD) was recently defined as a unique and stable geometric construction and used to define universal shape descriptors based on the contact graph associated with MDBD. In this paper, we demonstrate that by applying graph analysis tools to MDBD in conjunction with graph convolutional neural networks and graph kernels, one can effectively develop methods to perform similarity, retrieval and substructure matching from geometric models regardless of their native geometric representation. We show that our representation-agnostic approach achieves comparable performance with state-of-the-art geometric processing methods on standard yet heterogeneous benchmark datasets while supporting all valid geometric representations.

Analysis of the Lower Limb Muscles' Function for the Prevention of KNEE JOINT INJURIES of the Intramural Baseball Pitchers of Colleges and Universities

Purpose: The purpose of this analysis is to provide the basic data for the prevention of knee joint damages by analyzing differences in the isokinetic muscular function of knee joints as per the pitching speed of 21 intramu-ral baseball players of colleges and universities. Method: The subjects of this study were 21 intramural baseball players of colleges and universities, whose length of experiences were 2 to 7 years. By measuring the pitching speed, they were classified as S1 group whose maximum ball speed was 110km/h or greater, S2 group whose maximum ball speed was less than 110km/h to 100km/h or greater, and S3 group whose maximum ball speed was less than 100km/h, respectively. The isokinetic muscular strength of knee joints was measured for all of the 3 groups, and the strength of the left and right flexors and extensors were measured at 60°, 180°, and 240°, respectively. The data processing for this study was performed by using the SPSS 18.0 statistical program to calculate the mean and standard deviation for each of the items, and the one-way ANOVA was performed to compare the differences for each item by group, while using the Tukey method as an ex post analysis between the groups. Furthermore, the multiple linear regression was performed to identify the influence of the isokinetic muscular function of knee joints according to the angular speed on the pitching speed. The statistical significance level was set to p<.05, respec-tively. Results: The results of measuring the isokinetic muscular strength of knee joints are as follows. As for the PT and WPR measured at an angular speed of 60°, the S1 group turned out to be significantly higher(p<.05) in the left flexors and extensors than S3 group. As for the PT and WPR measured at an angular speed of 180°, the S1 and S2 groups turned out to be significantly higher(p<.05) in the left extensors than the S3 group. As for the PT measured at an angular speed of 240°, S1 and S2 groups in the left extensor turned out to be significantly high-er(p<.05) than S3 group. As for the WPR, S1 group turned out to be significantly(p<.05) higher than S3 group. The results of performing the multiple linear regression are as follows with a view to discover the effect of iso-kinetic muscular strength of knee joints on the pitching speed. At the angular speeds of 180° and 240°, the regression segments of the left knee joint extensors for both the PT and WPR turned out to have a significant ef-fect at the 5% level. R2, which is the explanatory power of the regression model which explains changes in the pitching speed for the left knee joint extensors, turned out to have an explanatory power in the range of 37.9-55.5%, respectively. Conclusion: Gathering the results above, it turned out that the higher the pitching speed for the group, the superior the muscular function, and in particular, the extensors on the left side demonstrated such remarkably pronounced characteristics. Such results suggest that the extensor muscles could influence the pitching speed for the stretching motion(acceleration) of the left legs during the pitching. Furthermore, in order to prevent injuries, attention ought to be paid to strengthening the counter muscular of the muscles which are primarily used.

Characterizing the boundary of the set of absolutely separable states and their generation via noisy environments

We characterize the boundary of the convex compact set of absolutely separable states, referred as AS, that cannot be transformed to entangled states by global unitary operators, in $2\ensuremath{\bigotimes}d$ Hilbert space. However, we show that the absolutely separable states of rank $(2d\ensuremath{-}1)$ are extreme points of such sets. We then discuss conditions to examine if a given full-rank absolutely separable state is an interior point or a boundary point of AS. Moreover, we construct two-qubit absolutely separable states which are boundary points but not extreme points of AS and prove the existence of full-rank extreme points of AS. Properties of certain interior points are also explored. We further show that by examining the boundary of the above set, it is possible to develop an algorithm to generate the absolutely separable states which stay outside the maximal ball. By considering paradigmatic noise models, we find the amount of local noise which the input entangled states can sustain, so that the output states do not become absolutely separable. Interestingly, we report that with the decrease of entanglement of the pure input state, critical depolarizing noise value, transferring an entangled state to an absolutely separable one, increases, thereby showing advantages of sharing nonmaximally entangled states. Furthermore, when the input two-qubit states are Haar uniformly generated, we report a hierarchy among quantum channels according to the generation of absolutely separable states.

A 2D and 3D discrete bisector function based on annulus

The bisector function is an important tool for analyzing and filtering Euclidean skeletons. In this paper, we are proposing a new way to compute 2D and 3D discrete bisector function based on annuli. From a continuous point of view, a point that belongs to the medial axis is the center of a maximal ball that hits the background in more than one point. The maximal angle between those points is expected to be high for most of the object points and corresponds to the bisector angle. This logic is not really applicable in the discrete space since we may miss some background points that can lead to small bisector angles. In this work we use annuli to find the background points in order to compute the bisector angle. Our approach offers the possibility to change the thickness of the annulus at a given point and is thus flexible when computing skeletons. Our work can be extended to nD and we propose the nD algorithm.

Pore Structure Characterization of Undisturbed Weathered Crust Elution-Deposited Rare Earth Ore Based on X-ray Micro-CT Scanning

As an environmentally compliant hydrometallurgical process, in situ leaching is extensively used by the mining industry to recover rare earth from weathered crust elution-deposited rare earth ore. In the in situ leaching system, the pore structure plays a dominant role in the permeability of the rare earth orebody and is one of the most important factors that influence the leaching performance. To study the pore structure characteristics of the rare earth ore, an undisturbed ore sample was scanned using X-ray micro-computed tomography. Based on the image processing techniques, visualization of the pore structure was realized and several parameters of 2D and 3D pore structures, such as porosity, pore volume, length, width, aspect ratio, and orientation, were obtained and statistically analyzed. The ball-and-stick model of large pore clusters was built by the maximal ball algorithm, and some of their detailed characteristics were obtained. The results indicate that the pore structure of weathered crust elution-deposited rare earth ore exhibits a multi-scale and strong heterogeneity characteristic. The distribution characteristics of pores between the vertical direction and the horizontal direction are obviously different. The small pores are more prevalent in number, but they make only a small contribution to the total pore volume. In addition, the orientation of the pores is anisotropic in both vertical and horizontal directions. Furthermore, the ball-and-stick model reveals that large pore clusters are composed of several interconnected void spaces, and most of them are small and irregular.