Uniform Density Distribution Research Articles

Excellent field–trapping properties of large ring–shaped REBCO melt–textured bulks fabricated by the single–direction melt growth (SDMG) method

Abstract Ring-shaped homogeneous YBCO and DyBCO bulks were successfully fabricated using the Single-Direction Melt Growth (SDMG) method. The bulks were directly grown from ring-shaped compacted powder using ring-shaped molds with an outer diameter of 50 mm and inner diameters of 15, 20, and 25 mm. The ring-shaped bulks exhibited high trapped fields inside the rings up to 1.2 T at 77 K. Analyses of trapped field distributions revealed uniform current density distributions along the orbital direction. Stacked ring bulks demonstrated even higher trapped fields, reaching 2.0 T at 77 K. It was confirmed for the stacked bulks that time-independent uniform trapped fields can be achieved by magnetizing at lower fields than fully magnetizing conditions. Observed paramagnetic magnetization of the SDMG-processed YBCO bulk was negligibly small below the detection limit, which is considered to be more suitable for bulk NMR/MRI applications than DyBCO. Additionally, we proposed a method to quantitatively evaluate trapped fields of superconducting bulks with various diameters and thicknesses, where the estimated average current densities from the maximum trapped fields for all the obtained ring-shaped bulks were above 104 A/cm2 at 77 K. These results indicate that SDMG is an effective method for fabricating high-quality, large-scale ring-shaped bulks with superior field-trapping properties.

Critical current density and AC magnetic susceptibility of high-quality FeTe0.5Se0.5 superconducting tapes

Iron telluride-selenium superconducting materials, known for their non-toxicity, ease of preparation, simple structure, and high upper critical fields, have attracted much research interest in practical application. In this work, we conducted electrical transport measurements, magneto-optical imaging, and AC magnetic susceptibility measurements on FeTe0.5Se0.5 superconducting long tapes fabricated via reel-to-reel pulsed laser deposition. Our transport measurements revealed a high critical current density that remains relatively stable even with increasing external magnetic fields, reaching over 1 × 105 A/cm2 at 8 K and 9 T. The calculated pinning force density indicates that normal point pinning is the primary mechanism in these tapes. The magneto-optical images demonstrated that the tapes show homogeneous superconductivity and uniform distribution of critical current density. The AC magnetic susceptibility measurements also confirmed their strong flux pinning nature of withstanding high magnetic field. Based on these characteristics, FeTe0.5Se0.5 superconducting tapes show promising prospects for applications under high magnetic field.

Simulation and Application of a New Type of Energy-Saving Steel Claw for Aluminum Electrolysis Cells

Aluminum electrolysis is a typical industry with high energy consumption, and the energy saving of aluminum electrolysis cells is conducive to the sustainable development of the ecological environment. The current density distribution on the steel claws of conventional aluminum electrolysis cells is uneven, resulting in a large amount of power loss. Therefore, a new type of current-equalized steel claw (CESC) is designed in this paper. The ANSYS simulation study shows that the CESC can achieve a more uniform current density distribution and reduce the voltage drop by about 36 mV compared with the traditional steel claw (TSC). In addition, the use of CESC optimizes the temperature distribution of the steel claws and reduces the risk of cracking and deformation. The results of the industrial application tests are highly consistent with the simulation results, confirming the accuracy of the simulation results. The economic benefit analysis shows that using CESC saves 114.1 kWh of electricity per ton of aluminum produced. If this technology can be promoted throughout China, it is expected to save up to 4.75 billion kWh of electricity annually. The development of CESC is promising and of great significance for improving the overall technical level of the aluminum electrolysis industry.

Expanding the Landscape of Phosphorous-Based Open Shell Species: Stable Mono-, Di-, and Trianionic Radicals Based on a Contorted Triphosphaalkene.

The stepwise reduction of the highly contorted truxene-based triphosphaalkene 1 using KC8 led to the isolation of mono-, di-and tri-anionic species. The solid-state molecular structures of mono- and diradical anionic species were elucidated by single crystal X-ray diffractions, revealing elongated P-C bonds and a pronounced "indene" aromatization compared to the parent system. All three radical species displayed distinct Electron Paramagnetic Resonance (EPR) spectra, providing compelling evidence for the open-shell electronic configuration of both the diradical and triradical species-an observation unprecedented in any previously reported phosphorous-based anionic polyradicals. Mulliken spin density calculations revealed a dominant localization of radical spin on a single phosphorous atom in the monoanion. In the dianion, spin localization is observed on two phosphorous atoms (~34% each), with a minor contribution from the third phosphorous (0.13%), while the trianion demonstrates a uniform distribution of spin density (~30%) across each phosphorous atom.

Characterisation of 3D-printable thermoplastics to be used as tissue-equivalent materials in photon and proton beam radiotherapy end-to-end quality assurance devices

Objective. To investigate the potential of 3D-printable thermoplastics as tissue-equivalent materials to be used in multimodal radiotherapy end-to-end quality assurance (QA) devices. Approach. Six thermoplastics were investigated: Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate Glycol (PETG), Polymethyl Methacrylate (PMMA), High Impact Polystyrene (HIPS) and StoneFil. Measurements of mass density ( ρ ), Relative Electron Density (RED), in a nominal 6 MV photon beam, and Relative Stopping Power (RSP), in a 210 MeV proton pencil-beam, were performed. Average Hounsfield Units (HU) were derived from CTs acquired with two independent scanners. The calibration curves of both scanners were used to predict average ρ, RED and RSP values and compared against the experimental data. Finally, measured data of ρ, RED and RSP was compared against theoretical values estimated for the thermoplastic materials and biological tissues. Main results. Overall, good ρ and RSP CT predictions were made; only PMMA and PETG showed differences >5%. The differences between experimental and CT predicted RED values were also <5% for PLA, ABS, PETG and PMMA; for HIPS and StoneFil higher differences were found (6.94% and 9.42/15.34%, respectively). Small HU variations were obtained in the CTs for all materials indicating good uniform density distribution in the samples production. ABS, PLA, PETG and PMMA showed potential equivalency for a variety of soft tissues (adipose tissue, skeletal muscle, brain and lung tissues, differences within 0.19%–8.35% for all properties). StoneFil was the closest substitute to bone, but differences were >10%. Theoretical calculations of all properties agreed with experimental values within 5% difference for most thermoplastics. Significance. Several 3D-printed thermoplastics were promising tissue-equivalent materials to be used in devices for end-to-end multimodal radiotherapy QA and may not require corrections in treatment planning systems’ dose calculations. Theoretical calculations showed promise in identifying thermoplastics matching target biological tissues before experiments are performed.

On the plastic deformation mechanism of Al0.6CoCrFeNi high entropy alloy: In-situ EBSD study and crystal plasticity modeling

In this study, in-situ tensile tests with electron back-scattered diffraction (EBSD) were conducted to reveal the microstructural effects on the plastic deformation behavior of dual-phase Al0.6CoCrFeNi high entropy alloys (HEAs). The in-situ EBSD results demonstrated a uniform distribution of dislocation density in the fine grain (FG) samples, whereas high dislocation density was predominantly localized near body-centered cubic (BCC) phases in the coarse grain (CG) samples. The difference in mechanical properties between face-centered cubic (FCC) and BCC phases caused stress concentration and cracking at the boundaries during tension. The FCC phase within FG samples exhibited excellent plasticity, effectively impeding the propagation and coalescence of microcracks emanating from the BCC phase into longer cracks. For CG samples, brittle cracks formed in BCC phases are easy to merge, thus evolving into long cracks. Crystal plasticity finite element analysis revealed that as the strain increases, stress distribution in FG samples tended to become more homogeneous, whereas for CG samples high stress concentration consistently occurred within BCC phases. The deformation characteristics of FG were attributed to the synergistic effect generated by the FCC phase with heterogeneous grain size and the BCC phase characterized by small grain size.

Dynamic variation of heat and mass transfer in a unitized regenerative fuel cell with a stepped channel during mode switching

Understanding the variation in heat and mass transfer during mode switching of a unitized regenerative fuel cell is essential for designing efficient flow channels and operational strategies. In this study, dynamic variation of current density, temperature, and species distribution during mode switching is investigated in a unitized regenerative fuel cell with a stepped flow channel. This work is conducted by a transient multi-physics model coupled with electrochemical reaction, heat and mass transfer, and phase change. Results indicate that the response time of current and temperature is prolonged as the mode-switching frequency rises. Using stepped channels instead of conventional straight channels can promote mode-switching and shorten the response time. Specifically, the stepped structure promotes airflow disturbance in flow channels, and the induced forced convection promotes heat and mass transfer. Besides, the stepped structure accelerates the stabilization of current density, temperature, and species during mode switching, leading to a more uniform current density distribution. In addition, the stepped structure promotes water discharge and convective heat transfer, improving the temperature uniformity of the catalyst layer. This study offers valuable insights for improving the durability of the membrane electrodes and improving the operational stability of unitized regenerative fuel cells during mode switching.

Three-dimensional simulation of a proton exchange membrane fuel cell with non-integrated metal foam as flow distributor

In proton exchange membrane fuel cells (PEMFCs), the presence of metal foam in the flow channels improves the polarity diagram and increases the cell generated power, but this leads to an increase in pressure drop and, as a result, an increase in parasitic power. In this study, two types of non-integrated arrangements of metal foam are introduced, which, in addition to having high generated power, have lower pressure drop, and subsequently, lower parasitic power, and will also result in a more uniform distribution of temperature and current density. In the first arrangement, which is called IPTG, an abbreviation of Increased Porosity Toward the gas diffusion layer (GDL), the channels are divided into four equal parts with variable porosities from 0.65 to 0.95, in such a way that the metal foam layer with the highest porosity (0.95) is located in the closest area to the GDL. In the second arrangement which is called Reduced Porosity Toward the GDL, the metal foam layer with the least porosity (0.65) is located in the closest area to the GDL. To make a better comparison between the present model and the conventional one, the net power parameter with subtracting parasitic power from generated electrical power of the fuel cell is calculated for all models. The numerical study of this paper is conducted by developing a three-dimensional computational fluid dynamics model by employing user-defined functions. The results show that the net power of the PEMFC with IPTG arrangement is 3.8 % higher than that of the one with integrated metal foam arrangement with a porosity of 0.95. Also, the higher the pores per inch (PPI) of metal foam used in the non-integrated metal foam model, the greater the net power of the fuel cell, so that, the net power of PEMFC with IPTG arrangement with PPI=80 is 3.2 % more than that of PPI=20.

A Scalable and Robust Water Management Strategy for PEMFCs: Operando Electrothermal Mapping and Neutron Imaging Study.

Effective water management is crucial for the optimal operation of low-temperature polymer electrolyte membrane fuel cells (PEMFCs). Excessive liquid water production can cause flooding in the gas diffusion electrodes and flow channels, limiting mass transfer and reducing PEMFC performance. To tackle this issue, a nature-inspired chemical engineering (NICE) approach has been adopted that takes cues from the integument structure of desert-dwelling lizards for passive water transport. By incorporating engraved, capillary microchannels into conventional flow fields, PEMFC performance improves significantly, including a 15% increase in maximum power density for a 25 cm2 cell and 13% for a 100 cm2 cell. Electro-thermal maps of the lizard-inspired flow field demonstrate a more uniform spatial distribution of current density and temperature than the conventional design. Neutron radiography provides evidence that capillary microchannels in the lizard-inspired flow field facilitate the efficient transport and removal of generated liquid water, thereby preventing blockages in the reactant channels. These findings present a universally applicable and highly efficient water management strategy for PEMFCs, with the potential for widespread practical implementation for other electrochemical devices.

Simulation and analysis of dam leakage inlet detection based on pseudo-flow field method

Seepage hazards in dams remain a critical issue in flood control engineering. The pseudo-flow field method has shown high efficacy in detecting seepage points within dam structures. This paper delves into the core characteristics of the pseudo-flow field method, aiming to accelerate its detection speed in practical engineering contexts. By employing the Laplace equation for electric current, we established a numerical model to simulate the method's application in real-world scenarios. The simulation reveals the key characteristics of potential and current density distributions along measuring lines within the pseudo-flow field. Both horizontal and vertical measuring lines show a peak distribution of current density and potential near the seepage point, gradually diminishing towards the periphery. Conversely, vertical measuring lines further from the seepage point exhibit minimal changes, presenting a uniform distribution of current density and potential. The results confirm that the pseudo-flow field method can effectively detect seepage locations and that strategic placement of measuring lines can markedly improve detection speed.

Large size shielded metal-ceramic cathodes

The technology for manufacturing large size shielded metal-ceramic cold cathodes is described. It has been shown that the use of a shielded metal-ceramic cathode allows to significantly increase the impedance of the vacuum diode and to form an electron beam of constant cross-sectional size or of the required size (up to 400 mm wide) with a fairly uniform electron beam current density distribution (≤15%).It has been found that the emission decline of the shielded metal-ceramic cathode, like that of the metal-dielectric cathode operating at a high repetition rate (≥100 pps), is significant at the beginning of the process and then slows down, allowing continuous operation for up to 40 h. Both cathodes require periodic cleaning of the plates, which is more difficult for metal-ceramic plates.At the same time, a metal-ceramic cathode works better at low vacuum, allowing twice as much current to be generated (in the same geometry) as a metal-dielectric cathode, while reducing the accelerating voltage by ∼15%. However, metal-ceramic plates are about 100 times more expensive to manufacture than dielectric plates for a metal-dielectric cathode.Therefore, the choice of cathode type for vacuum diode accelerators is not a trivial problem, but depends on many factors that must be taken into account in each case and for each radiation technology.

Gradient catalyst layer design towards current density homogenization in PEM water electrolyzer with serpentine flow field

The inhomogeneous current density distribution might cause irreversible damage to the membrane electrode assemblies of proton exchange membrane water electrolyzers. Herein, the impact of gradient catalyst distribution on the current density uniformity inside the electrolyzer with serpentine flow field is investigated using a three-dimensional model. The gradient catalyst distribution in parallel and vertical flow directions is considered. It is found that, at low working voltage (1.8 V), gradient catalyst loading in the vertical flow direction would enhance the current density distribution uniformity by 77.6 %, and at the same time improve the electrolyzer performance by up to 4.0 %, whereas in parallel flow direction the corresponding improvement is by 34.5 % and 4.17 %, respectively. At high working voltage of 2.4 V, due to the pronounced impact of mass transportation process, similar and limited improvement in the current density uniformity (11.47–11.87 %) and electrolyzer performance (1.3–1.45 %) is found under the gradient catalyst loading design in both flow directions. This study provides important guidance for the design of proton exchange membrane water electrolyzer using serpentine flow field.

Space-resolved electron density and temperature evaluation by x-ray pinhole camera method in an ECR plasma

X-ray emission characterization provides valuable insights about electron cyclotron resonance (ECR) plasmas. In principle, space-resolved spectroscopic techniques can be used to reveal spatial distributions of electron density and temperature. In the PANDORA (Plasma for Astrophysics, Nuclear Decay Observation, and Radiation for Archaeometry) project framework, and within the collaboration between the Atomki and INFN-LNS laboratories, we developed a high-resolution full-field x-ray pinhole setup. This setup incorporates advanced analysis techniques for single photon counted imaging in high dynamical range mode, enabling x-ray imaging and space-resolved spectroscopy at high spatial and energy resolution (560 μm and 242 eV @ 8.1 keV, respectively). Here, we introduce an innovative technique for quantitatively evaluating the local electron density and temperature of plasma, as the first application of such a method in an ECR setup. Specifically, we examine an argon plasma heated by 200 W microwave power at 14 GHz. Our analysis includes a retrospective comparison with past x-ray data collected from other ECR ion source setups. Our findings clearly reveal the formation of a plasmoid–halo structure within the plasma chamber, characterized by a dense and hot plasma almost totally enclosed inside the ECR magnetic iso-surface (the plasmoid). This plasmoid exhibits nearly uniform distribution of electron density and temperature, with only gentle gradients of both the parameters toward its edges. Inside the halo, x-ray emission is minimal or even negligible. Notably, cusp structures correspond to magnetic branches where deconfined electrons impinge upon the plasma chamber walls and endplates. The average values of temperature and density measured inside the plasmoid are 12.44±1.84 keV and (1.66±0.15)×1017 m−3, respectively.

Experimental development of packing structures in a gas-particle trickle flow heat exchanger for application in concentrating solar tower systems

Ceramic particles represent a viable alternative as heat transfer and storage medium in concentrating solar tower systems. The particles are heated in solar-receivers close to 1000 °C. To utilize the stored energy in the particles, an air-particle direct-contact trickle-flow heat exchanger has been identified as suitable for this task. To date, no design recommendations exist that identify an optimized packing structure capable of providing a high particle volume fraction and a uniform spatial particle density distribution for a given grain type. Consequently, an experimental selection process is presented in this work to assess various packing structures for a given grain type in a trickle-flow reactor. The experiments were conducted with countercurrent flowing air at ambient conditions and 1 mm bauxite particles. A variety of packing structures were investigated at varying media flow rates. For each flow condition, the particle volume fraction was determined, as well as the particle distribution in a separate analysis. The cold experiments yielded a clear image of a preferred packing geometry, which will be discussed in detail. The results will serve as the basis for further hot experiments and thermal performance analysis in future work, where the packing geometry can be refined iteratively if necessary.

Improving the Uniform Distribution of Water Flux Density in Sprinkler Spray by Adopting Various Installation Methods

In a sprinkler system, the nonuniform water flux distribution resulting from the sprinkler head design, specifically due to the deflector and frame, impedes the primary extinguishing surface cooling effect of the sprinkler. In this study, the effects of the distance between heads, supplying flow rate, head installation direction, and head installation height on the uniformity of the water flux density distribution were investigated. Simulations were conducted using the water flux distribution reproduction method proposed in a previous study. As the distance between heads decreased, water was supplied to the bottom of the head, resulting in the improved uniformity of the water flux distribution. When the flow rate was corrected with the changes in the distance between the heads to maintain the average water flux density supplied to the floor, a uniform water flux distribution was observed even when the distance between heads was relatively large. In the case of head installation direction, the most uniform distribution was observed when the sprinkler heads were installed alternately at angles corresponding to 0° and 135°. As the installation height of the sprinkler heads increased, the difference between the maximum and minimum local water flux densities decreased, leading to a more uniform water flux density distribution.

Magneto-Mechanical Coupling Analysis of Automobile Brake by Wire System Based on Giant-Magnetostrictive Actuator

Addressing the drawbacks of traditional automotive braking systems, including long hydraulic lines, heavy weight, and slow response speed, a new type brake by wire system based on giant-magnetostrictive material is proposed, which consists of giant-magnetostrictive actuator module and mechanical drive module. In this paper, CATIA software is used to establish a three-dimensional model of the brake. In order to verify the reliability of the model, giant-magnetostrictive actuator is taken as the research object, and COMSOL software is used to simulate different working conditions of automobile braking. A Magneto-mechanical coupling model was established and Magneto-mechanical coupling analysis of the actuator was carried out. The simulation results show that the aluminum shell material is superior to the 45 steel shell material. The inductance direction of the actuator is approximately elliptical from top to bottom, with uniform distribution of magnetic flux density and stress. The output stress is 5e4N/m2, and the maximum elongation is 0.1071mm. Finally, the driving efficiency of GMA was verified on an optical isolation platform, and comparative experiments were conducted before and after optimization using instruments such as laser displacement samplers, Tesla meters, and force sensors. The experimental results indicate that by optimizing the housing material and structure of the actuator, the displacement increased from 0.05188mm to 0.1003mm, magnetic induction increased from 42.9mT to 79.9mT, resulting in an increase of 41.6% and 42.7% respectively, and the maximum output force was 4752.3N. It makes a certain contribution to the application of GMA to automotive braking field and further proves the effectiveness of GMA in the application of automobile brake by wire system.

Constructing Robust LiF‐Enriched Interfaces in High‐Voltage Solid‐State Lithium Batteries Utilizing Tailored Oriented Ceramic Fiber Electrolytes

AbstractThe pursuit of high‐performance energy storage devices has fueled significant advancements in the all‐solid‐state lithium batteries (ASSLBs). One of the strategies to enhance the performance of ASSLBs, especially concerning high‐voltage cathodes, is optimizing the structure of composite polymer electrolytes (CPEs). This study fabricates a high‐oriented framework of Li6.4La3Zr2Al0.2O12 (o‐LLZO) ceramic nanofibers, meticulously addressing challenges in both the Li metal anode and the high‐voltage LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode. The as‐constructed electrolyte features a highly efficient Li+ transport and robust mechanical network, enhancing both electron and ion transport, ensuring uniform current density distribution, and stress distribution, and effectively suppressing Li dendrite growth. Remarkably, the Li symmetric cells exhibit outstanding long‐term lifespan of 9800 h at 0.1 mA cm−2 and operate effectively over 800 h even at 1.0 mA cm−2 under 30 °C. The CPEs design results from the formation of a gradient LiF‐riched SEI and CEI film at the Li/electrolyte/NCM811 dual interfaces, enhancing ion conduction and maintaining electrode integrity. The coin‐cells and pouch cells demonstrate prolonged cycling stability and superior capacity retention. This study sets a notable precedent in advancing high‐energy ASSLBs.

Highly Sodiophilic Heterostructures Toward Dendrite‐Free Sodium Metal Batteries

AbstractThe utilization of Al current collector for the sodium deposition is considered ideal for achieving a low‐cost, high‐energy‐density sodium metal battery. However, the poor affinity between sodium and Al leads to uneven sodium plating/stripping, which poses a significant challenge in the pursuit of a stable sodium metal anode. Herein, a heterostructure (V/VOx)‐modified Al current collector is proposed, which effectively enables a highly reversible Na plating/stripping process, and inhibits Na dendrites growth. Experimental results and theoretical calculations demonstrate that the V/VOx@Al not only exhibits strong sodiophilicity, but also ensures a uniform current density distribution. Thanks to these merits, the assembled cells demonstrate excellent performances with low nucleation overpotential (11 mV at 1 mA cm−2), and long cycle life (2750 h) with minimal voltage polarization (13 mV at 1 mA cm−2). More impressively, the assembled full cell displays remarkable stability, sustaining 1400 cycles at 10 C. This work provides valuable insights for the development of more stable sodium metal batteries.

Energy losses of highly charged Arq+ ions during grazing incidence on tungsten surfaces

In this study, we investigate the energy loss of highly charged ions interacting with various tungsten surfaces. The analysis primarily focuses on elucidating the impact of electron density distributions on energy loss of ions. Furthermore, we explore the correlation between surface azimuthal angles and energy loss under both uniform and inhomogeneous electron density distributions. Utilizing the classical over-the-barrier model (COBM), simulations involving trajectory calculations, energy loss, charge-exchange processes, and surface electron distributions, etc., were performed. Remarkably, the significant influence of axial channeling of surfaces on ion energy loss is observed. For the comparison of ion energy loss under uniform and inhomogeneous electron density distributions, the results reveal a more pronounced effect of electron density inhomogeneity on ion energy loss at higher energy-loss values. Additionally, the calculated energy-loss spectra of Ar16+ ions grazing on graphite surfaces show reasonable agreement with experimental data. These findings are crucial for understanding the surface structure of crystals.

Clinical evaluation of pulmonary quantitative computed tomography parameters for diagnosing eosinophilic chronic obstructive pulmonary disease: Characteristics and diagnostic performance.

To investigate the characteristics and diagnostic performance of quantitativecomputed tomography (QCT) parameters in eosinophilic chronic obstructive pulmonary disease (COPD) patients. High-resolution CT scans of COPD patients were retrospectively analyzed, and various emphysematous parenchyma measurements, including lung volume (LC), lung mean density (LMD), lung standard deviation (LSD), full-width half maximum (FWHM), and lung relative voxel number (LRVN) were performed. The QCT parameters were compared between eosinophilic and noneosinophilic COPD patients, using a definition of eosinophilic COPD as blood eosinophil values ≥ 300 cells·µL-1 on at least three times. Receiver operating characteristic curves and area under the curve (ROC-AUC) and python were used to evaluate discriminative efficacy of QCT. Noneosinophilic COPD patients had a significantly lower TLMD (-846.3 ± 47.9 Hounsfield Unit[HU]) and TFWHM(162.5 ± 30.6 HU) compared to eosinophilic COPD patients (-817.8 ± 54.4, 177.3 ± 33.1 HU, respectively) (p = 0.018, 0.03, respectively). Moreover, the total LC (TLC) and TLSD were significantly lower in eosinophilic COPD group (3234.4 ± 1145.8, 183.8 ± 33.9 HU, respectively) than the noneosinophilic COPD group (5600.2 ± 1248.4, 203.5 ± 20.4 HU, respectively) (p = 0.009, 0.002, respectively). The ROC-AUC values for TLC, TLMD, TLSD, and TFWHM were 0.91 (95% confidence interval [CI], 0.828-0.936), 0.66 (95% CI, 0.546-0.761), 0.64 (95% CI, 0.524-0.742), and 0.63 (95% CI, 0.511-0.731), respectively. When the TLC value was 4110 mL, the sensitivity was 90.7% (95% CI, 79.7-96.9), specificity was 77.8% (95% CI, 57.7-91.4) and accuracy was 86.4%. Notably, TLC demonstrated the highest discriminative efficiency with an F1 Score of 0.79, diagnostic Odds Ratio of 34.3 and Matthews Correlation Coefficient of 0.69, surpassing TLMD (0.55, 3.66, 0.25), TLSD (0.56, 3.95, 0.26), and TFWHM (0.56, 4.16, 0.33). Eosinophilic COPD patients exhibit lower levels of emphysema and a more uniform density distribution throughout the lungs compared to noneosinophilic COPD patients. Furthermore, TLC demonstrated the highest diagnostic efficiency and may serve as a valuable diagnostic marker for distinguishing between the two groups.