Structural Stability Research Articles

Effects of B2 ordered structure on the mechanical properties of TiZrHfCoNiCu high-entropy alloy

High-entropy alloys (HEAs) were once considered to be typical disordered solid solutions with various atoms randomly distributed in a lattice. Recent studies have found that owing to the chemical complexity of multiple primary elements, HEAs may also form ordered structures that directly influence their mechanical properties. In this study, B2-ordered and body-centered-cubic-disordered structures of TiZrHfCoNiCu HEAs were established using the special quasi-random structure method. The results of first principles calculations and ultrasonic wave velocity measurements indicated that the B2-ordered TiZrHfCoNiCu HEA exhibited superior phase stability, structural stability, and mechanical properties such as strength and hardness. Significantly, the results of this study revealed the physical mechanisms underlying the excellent mechanical properties of ordered HEAs and can guide their design and development accordingly.

Effects of steel bolts on retrofitting the buckling performance of storage rack system uprights

Storage rack systems, essential for product storage, encounter design challenges, particularly for uprights under axial loading. Despite being produced from thin-walled steel sheets, these systems are required to support excessive loads. Extensive research has focused on maximizing the load-bearing capacity of rack uprights in recent years. This study aims to enhance the axial load capacity of upright profiles through a retrofitting method of installing steel bolts and spacers. Experimental, numerical, and analytical evaluations were conducted to assess the effectiveness of bolt installation in enhancing axial strength of the uprights. Bolt installation altered buckling modes, suppressing distortional buckling. Results consistently showed an increase in axial load capacity with bolt installation, particularly notable in taller uprights. Comparison of experimental, numerical, and analytical results revealed good alignment, highlighting the positive impact of bolt installation on structural stability. Numerical analysis slightly underestimated experimental outcomes, especially for longer lengths, while the analytical approach showed a combination of overestimation and underestimation, with significant overestimation for longer lengths. The study concludes that bolt installation effectively increases the axial load capacity, especially for taller uprights. These findings offer remarkable insights on the positive effect of bolt installation for optimizing storage rack systems by enhancing structural stability and eliminating distortional buckling.

On the mechanism of Ca(OH)2 structure modulation by surfactants: Experimental and calculative studies

Surfactants are widely used for structure modulation of calcium-based materials. However, the modification mechanisms underlying the CaO digestion improved by surfactants for Ca(OH)2 production remain unclear. This study employed experiment methods, Density Functional Theory (DFT), and Molecular Dynamics methods (MD) to reveal the mechanism of surfactant modulation at a molecular level. The adsorption energy of Primary Alcohol Ethoxylate (AEO), Sodium Dodecyl Sulfate (SDS), H2O, and Dodecyl Trimethyl Ammonium Bromide (DTAB) on CaO(001) surface were −52.62, −51.98, –23.79, and 3.96 kcal/mol, respectively. The strong chemisorption of AEO and SDS on the surface of CaO improved its structure stability. AEO and SDS weakened the diffusion of H2O to CaO surface, thus causing the reaction between CaO and H2O to be suppressed. After being modulated by SDS and AEO, better crystallinity of Ca(OH)2 and finer crystalline grains were observed with the formation of developed pore structure. AEO has a longer molecular chain, giving better modification performance. On the contrary, DTAB accelerated the diffusion of H2O to CaO surface, leading to more energy released and causing the fast growth of Ca(OH)2 crystals, as evidenced by the much larger particle size compared to that of AEO and SDS. This process led to the creation of a larger pore structure. Desulfurization was used as a performance indicator to evaluate the surfactants modulation efficacy. The sulfur capacity of Ca(OH)2 regulated by 1 % AEO was 100.05 mg/g, being the highest among the used surfactants. For comparison, the sulfur capacity without additives was 49.64 mg/g. This study shows that nonionic surfactants are an ideal choice for regulating the structure of Ca(OH)2, as they can effectively inhibit crystal growth.

Nanocrystal Materials for Resistive Memory and Artificial Synapses: Progress and Prospects.

Resistive random-access memory (RRAM) is considered to be the most promising next-generation non-volatile memory because of its low cost, low energy consumption, and excellent data storage characteristics. However, the on/off (SET/RESET) voltages of RRAM are too random to replace the traditional memory. Nanocrystals (NCs) offer an appealing option for these applications since they combine excellent electronic/optical properties and structural stability and can address the requirements of low-cost, large-area, and solution-processed technologies. Therefore, the doping NCs in the function layer of RRAM are proposed to localize the electric field and guide conductance filaments (CFs) growth. The purpose of this article is to focus on a comprehensive and systematical survey of the NC materials, which are used to improve the performance of resistive memory (RM) and optoelectronic synaptic devices and review recent experimental advances in NC-based neuromorphic devices from artificial synapses to light-sensory synaptic platforms. Extensive information related to NCs for RRAM and artificial synapses and their associated patents were collected. This review aimed to highlight the unique electrical and optical features of metal and semiconductor NCs for designing future RRAM and artificial synapses. It was demonstrated that doping NCs in the function layer of RRAM could not only improve the homogeneity of SET/RESET voltage but also reduce the threshold voltage. At the same time, it could still increase the retention time and provide the probability of mimicking the bio-synapse. NC doping can significantly enhance the overall performance of RM devices, but there are still many problems to be solved. This review highlights the relevance of NCs for RM and artificial synapses and also provides a perspective on the opportunities, challenges, and potential future directions.

Decoding the mechanism governing the structural stability of wheat germ agglutinin and its isolated domains: A combined calorimetric, NMR, and MD simulation study.

Wheat germ agglutinin (WGA) demonstrates potential as an oral delivery agent owing to its selective binding to carbohydrates and its capacity to traverse biological membranes. In this study, we employed differential scanning calorimetry and molecular dynamics simulations to comprehensively characterize the thermal unfolding process of both the complete lectin and its four isolated domains. Furthermore, we present the nuclear magnetic resonance structures of three domains that were previously lacking experimental structures in their isolated forms. Our results provide a collective understanding of the energetic and structural factors governing the intricate unfolding mechanism of the complete agglutinin, shedding light on the specific role played by each domain in this process. The analysis revealed negligible interdomain cooperativity, highlighting instead significant coupling between dimer dissociation and the unfolding of the more labile domains. By comparing the dominant interactions, we rationalized the stability differences among the domains. Understanding the structural stability of WGA opens avenues for enhanced drug delivery strategies, underscoring its potential as a promising carrier throughout the gastrointestinal environment.

Thermally stabilized polyacrylonitrile/polyphenylene sulfide composite membranes for efficient emission control in harsh environments

In harsh and complex environments, the emission of polluted air poses significant challenges to traditional filtration systems. In contrast to conventional approaches which primarily involve the incorporation of antioxidants into filter materials, this study introduces a novel methodology. Here, we employed polyacrylonitrile (PAN) as a coating for polyphenylene sulfide (PPS) fibers. Furthermore, we innovatively utilized a needle punching process in conjunction with segmented heat treatment to manufacture PAN-PPS composite filter membranes capable of withstanding extreme environmental conditions. During the segmented heat treatment process, the molecular structure of PAN coating underwent a series of changes, ultimately transforming into a heat-resistant ring trapezoidal structure, providing protection for PPS fibers that are prone to oxidation, and thereby enhancing the structural stability of composite filter membrane. Experimental results demonstrated a significant improvement in the mechanical properties of PAN-PPS composite fabric after segmented heat treatment, with the tensile strength increasing by 71.7 % and the Young’s modulus by 91.6 %. Additionally, the flame retardancy and hydrophobic properties of composite membranes were significantly enhanced, exhibiting the excellent stability and better filtration performance in extreme environments. This approach not only addresses the challenges posed by incorporating nano antioxidants into the spinning process but also significantly enhances the high-temperature resistance of the materials. This enables PAN-PPS composite filter bags to effectively control the emission of polluted gases in extreme environments. Furthermore, the thermal treatment process of the PAN coating is easy to implement and cost-effective, providing a novel strategy for the development of extremely high-temperature resistant filtering materials. This makes it possible to explore the development of flexible, high-performance air filtering materials for extreme environments in the future.

Exploiting Co-C interface and graphitic carbon belts for enhanced structural stability of a porous layered Co-C catalyst for CO2 hydrogenation

Addressing the urgent need for efficient CO2 reduction, a novel Co@C catalyst was synthesized through the pyrolysis of a unique layered metal–organic framework (MOF), featuring tunable thickness, pore sizes. The CO2 hydrogenation performance demonstrates an enhancement by an optimized structure that significantly improves stability, maintaining a 25% CO2 conversion rate over an extended 80-hour period. The catalyst's composite structure exhibits a dual-confinement effect, where the Co-C interface and graphitic carbon belt stabilize Co nanoparticles, preventing sintering during reaction cycles. This study delves into the structural modifications necessary for catalytic optimization in CO2 hydrogenation, offering valuable insights for designing efficient catalysts for CO2 reduction and advancing sustainable energy solutions.

Interface chemical reconstruction with residual lithium compounds on nickel-rich cathode by nonstoichiometrical MoO3-x coating enables high stability

The layered lithium nickel-rich cathodes have become one of the most promising candidates for next-generation lithium-ion batteries with high energy density, However, the nickel-rich cathode suffers from a rapid decay of capacity due to their intrinsic instability and undesirably residual lithium compounds originated from LiNiO2 structural changes on the surface, hindering large-scale commercial application. Herein, a continuous and uniform oxygen vacancy enriched-MoO3-x coating was successfully synthesized and reacted residual lithium compounds as a functional layer on the cathode. Such chemically reconstructed coating (Li2MoO4) strategy endows the 1 wt% MoO3-x coated NCA cathode with a fast Li+ ions transport and enhanced structural stability, leading to an outstanding discharge capacity of 214.0 mAh g−1 at 0.1C (1C = 270 mA g−1), a better capacity retention of 80.3 % after 120 cycles at 0.5C, and an excellent high rate capability of 120 mAh g−1 at 5C cycled in voltage range of 2.75 V–4.3 V. This work provides an effective strategy to modulate surface structure towards advanced Ni-rich cathodes for high-performance lithium-ion batteries.

Evaluation of hydrogen storage capacity of two-dimensional Sc2N MXene: A DFT study

In this work, the efficiency of hydrogen storage on Sc2N MXenes monolayer is systematically investigated using first-principles calculations. After determining the structural stability of designed monolayer, adsorption sites for the storage of hydrogen atoms (H) and molecules (H2) are identified. The calculated binding energies have indicated that the hydrogen atoms have favorable adsorption at the center or H site of the Sc atoms and hydrogen molecules are found to be the most stable when adsorbed on the top/T site of Sc atoms. The binding energy assessment identified the chemisorption for hydrogen atoms and Kubas-type interactions for H2. To further ascertain the suitability of the Sc2N monolayer for hydrogen storage various analyses including binding energy, partial density of states (PDOS), electron localization function (ELF), Mullikan charge analysis and Hirshfeld charge analysis are conducted. In order to determine the thermal stability of the Sc2N monolayer, desorption temperature with respect to pressure and molecular dynamics study has also been conducted and found the monolayer thermally stable. Desorption isotherms condition with increasing pressure confirms the gravimetric storage uptake. The obtained results have revealed that the hydrogen storage capacity considered monolayer has reached up to 10.8 wt%, which is reasonably high. Hence, the obtained results of hydrogen atom and molecules adsorption have clearly established that Sc2N monolayer is as an exemplary, stable, reliable and efficient medium for hydrogen storage applications.

Multifunction magnetic chiral MOF composite: A novel post-synthetic super catalyst for enhancing the asymmetric CO2 fixation

Here in, a novel neutral Chiral Metal−Organic Framework (CMOF) composite, Cu(II)-l-proline/TCT/APTES/Fe3O4/MIL-101(Fe) (Cu(II)-HPro/TCT/APTES/Fe3O4/MIL-101(Fe)), has been derived from the chiral Cu(II)-l-proline complex (Cu(II)-HPro) attached to TCT/APTES/Fe3O4 and MIL-101(Fe). Achiral MIL-101(Fe) was chiralized by the incorporation of chiral Cu(II)-HPro complex anchored to TCT/APTES/Fe3O4 using ultrasonic-assisted electrostatic self-assembly technique (postsynthetic modification). The resulted super catalyst has chiral species acting as Lewis base sites, together with two active metal sites (Fe and Cu) acting as Lewis acid centers leading to multifunctionality. Due to chiral auxiliary Lewis bases and Lewis acids, the catalytic activity of the Cu(II)-HPro/TCT/APTES/Fe3O4/MIL-101(Fe) composite was evaluated in asymmetric catalysis of prochiral substrates. This asymmetric super catalyst has proved to be highly active in CO2 fixation reaction at ambient pressure, low-temperature, solvent-free medium with high conversion and enantioselectivity. Based on the results, enantiomeric excess (ee) [97 % (S)], carbonate selectivity (>99 %), and conversion (>99 %) all demonstrate the superior performance of the investigated catalytic system. Furthermore, the magnetic characteristic, together with excellent structure stability, leads to high recyclability for 7 runs without a significant reduction of catalytic activity. The outcomes showed that chiralization of MIL-101(Fe) could occur through a simple and green approach, which may be a practical way to create chiral multifunctionalized metal−organic frameworks (MOFs).

A comparative study of the high-pressure structural stability of zirconolite materials for nuclear waste immobilisation

We present a comparative study of the high-pressure behaviours of the nuclear waste immobilisation materials zirconolite-2 M, −4M, –3O, and −3T. The materials are studied under high-pressure conditions using synchrotron powder X-ray diffraction. For zirconolite-2 M we also performed density-functional theory calculations. A new triclinic crystal structure (space group P1¯), instead of the previously assigned monoclinic structure (space group C2/c) is proposed for zirconolite-2 M. We named the triclinic structure as zirconolite-2TR. We also found that zirconolite-2TR undergoes a phase transition at 14.7 GPa to a monoclinic structure described by space group C2/c, which is different than the high-pressure structure previously proposed in the literature. These results are discussed in comparison with previous studies on zirconolite-2 M and the related compound calzirtite. For the other three zirconolite structures (4 M, 3O, and 3 T) this is the first high-pressure study, and we find no evidence for pressure induced phase transitions in any of them. The linear compressibility of the studied compounds, as well as a room-temperature pressure–volume equation of state, are also presented and discussed.

Efficient synthesis of benzyl-protected cyclic lysine on Pt/m-Al2O3 catalysts and its application in functional nylon-6 copolymers production

Functional nylon-6 polymers, particularly those with special properties such as antibacterial, flame retardant, and specialized thermal properties, have a wide range of applications. However, the efficient synthesis of these polymer monomers has long remained a challenge. Benzyl-protected cyclic lysine (BCL) is a potentially functional monomer, and this article proposes an efficient method for the synthesis of benzyl-protected cyclic lysine on a supported platinum catalyst. Compared to existing techniques, this approach offers higher synthesis efficiency and sustainability. Pt/m-Al2O3 (microspherical Al2O3) catalysts were prepared using a vacuum impregnation method and showed good activity and selectivity in the production of benzyl-protected cyclic lysine. The conversion rate of α-amino-ε-caprolactam (α-ACL) was 100%, and the selectivity of BCL was 96.0%. The Pt/m-Al2O3 catalyst maintained good stability over multiple reaction cycles. The reaction mechanism and thermodynamics of functionalized α-ACL were also investigated. The copolymer synthesized with the prepared BCL showed similar structure and thermal stability to pure nylon-6, indicating possible unique functional properties. This study provides a route for the synthesis of cyclic lysine protected with various groups and its potential applications in the field of polymer chemistry.

High cycling stability of MnO2 cathode for aqueous Mg-ion batteries enabled by Fe doping

MnO2 has been widely investigated as a promising cathode material for aqueous magnesium-ion batteries, which, however, suffers from the severe capacity fading during charge/discharge cycling. In present work, we report that the doping of Fe in α-MnO2 enlarges the lattice and alleviates the Jahn–Teller distortions and thus accelerates the Mg2+ diffusion and strengthens the structural stability. Consequently, the capacity retention remarkably increases from 44.3 % to 85.2 % after 1000 cycles by Fe doping. Furthermore, it is found for the first time that Fe doping enables the co-insertion of H+ and Mg2+ in the tunnels of α-MnO2, which improves remarkably the specific capacity from 131.9 to 205.9 mA h g−1 at 0.1 A g−1.

Lattice Engineering via Transition Metal Ions for Boosting Photoluminescence Quantum Yields of Lead-Free Layered Double Perovskite Nanocrystals.

Lead-free layered double perovskite nanocrystals (NCs), i.e., Cs4M(II)M(III)2Cl12, have recently attracted increasing attention for potential optoelectronic applications due to their low toxicity, direct bandgap nature, and high structural stability. However, the low photoluminescence quantum yield (PLQY, <1%) or even no observed emissions at room temperature have severely blocked the further development of this type of lead-free halide perovskites. Herein, two new layered perovskites, Cs4CoIn2Cl12 (CCoI) and Cs4ZnIn2Cl12 (CZnI), are successfully synthesized at the nanoscale based on previously reported Cs4CuIn2Cl12 (CCuI) NCs, by tuning the M(II) site with different transition metal ions for lattice tailoring. Benefiting from the formation of more self-trapped excitons (STEs) in the distorted lattices, CCoI and CZnI NCs exhibit significantly strengthened STE emissions toward white light compared to the case of almost non-emissive CCuI NCs, by achieving PLQYs of 4.3% and 11.4% respectively. The theoretical and experimental results hint that CCoI and CZnI NCs possess much lower lattice deformation energies than that of reference CCuI NCs, which are favorable for the recombination of as-formed STEs in a radiative way. This work proposes an effective strategy of lattice engineering to boost the photoluminescent properties of lead-free layered double perovskites for their future warm white light-emitting applications.

Study on Confined Water in Flexible Graphene/GO Nanochannels.

The structural evolution of flexible nanochannels within a 2D material membrane, influenced by the ingress of water molecules, plays a crucial role in the membrane's filtration and structural stability. However, the experimental observation of nanoscale water is challenging, and current studies mostly focus on rigid nanochannels. Further investigation on the nanoconfined water is urgently needed, considering the flexibility and deformation of the channel. In this work, MD simulations and theoretical analyses are conducted to investigate the water structure and thermodynamic properties when confined within both rigid and flexible graphene/graphene oxide (GO) nanochannels. In free rigid graphene nanochannels, the interlayer distance exhibits a quantized increase with the number of water molecules, along with sudden changes in entropy, potential energy, and free energy of the water molecules. Meanwhile, in flexible graphene nanochannels, the average interlayer space increases linearly with the number of water molecules. In free rigid GO nanochannels, with the increase of oxidation concentration, the quantized increase in the interlayer space gradually diminishes, accompanied by a decrease in both potential energy and free energy. This work provides insights into the configurational evolution of flexible nanochannels within water, offering guidance in fields such as desalination and mass transport of 2D material membranes.

Efficient, Color-Stable, Pure-Blue Light-Emitting Diodes Based on Aromatic Ligand-Engineered Perovskite Nanoplatelets.

Perovskite nanoplatelets (NPLs) show great potential for high-color-purity light-emitting diodes (LEDs) due to their narrow line width and high exciton binding energy. However, the performance of perovskite NPL LEDs lags far behind perovskite quantum dot-/film-based LEDs, owing to their material instability and poor carrier transport. Here, we achieved efficient and stable pure blue-emitting CsPbBr3 NPLs with outstanding optical and electrical properties by using an aromatic ligand, 4-bromothiophene-2-carboxaldehyde (BTC). The BTC ligands with thiophene groups can guide two-dimensional growth and inhibit out-of-plane ripening of CsPbBr3 NPLs, which, meanwhile, increases their structural stability via strongly interacting with PbBr64- octahedra. Moreover, aromatic structures with delocalized π-bonds facilitate charge transport, diminish band tail states, and suppress Auger processes in CsPbBr3 NPLs. Consequently, the LEDs demonstrate efficient and color-stable blue emissions at 465 nm with a narrow emission line width of 17 nm and a maximum external quantum efficiency (EQE) of 5.4%, representing the state-of-the-art CsPbBr3 NPL LEDs.

Effect of biaxial tensile-compressive deformation on the optoelectronic properties of monolayers of MoTe2 with adsorbed alkali metals X (X = Li, Na, K, Rb, Cs): a first principles

Based on a first-principles approach, the effects of tensile-compression deformation on the structural stability, electronic structure, and optical properties of monolayers of MoTe2 adsorbed with alkali metal atoms X (X = Li, Na, K, Rb or Cs) were calculated. It was found that the structural stability of the MoTe2 monolayer after adsorption of Li atoms was the most stable, with the smallest adsorption and formation energies and the smallest adsorption height. The movement of the Fermi energy toward the conduction band makes the system an n-type semiconductor. Subsequently, the adsorbed Li-MoTe2 monolayers were selected for tensile-compressive deformation, and with the increase of tensile deformation, the band gap decreased to zero at 10% deformation and exhibited metallic properties. As compressive deformation grows, the band gap shifts from direct to indirect, and metallic characteristics emerge when deformation approaches −10%. The Te-s and Te-p orbital electrons near the Fermi energy level and Mo-d orbitals make the main contribution to the adsorbed alkali metal molybdenum ditelluride system. In terms of optical characteristics, the MoTe2 system after alkali metal adsorption deformation is blue-shifted/ red-shifted at the absorption/reflection peak. These discoveries may help to broaden the possible applications of MoTe2 in low-dimensional electron-emitting devices.

Dual-Site Doping in Transition Metal Oxide Cathode Enables High-Voltage Stability of Na-Ion Batteries.

Designing cathode materials that effectively enhancing structural stability under high voltage is paramount for rationally enhancing energy density and safety of Na-ion batteries. This study introduces a novel P2-Na0.73K0.03Ni0.23Li0.1Mn0.67O2 (KLi-NaNMO) cathode through dual-site synergistic doping of K and Li in Na and transition metal (TM) layers. Combining theoretical and experimental studies, this study discovers that Li doping significantly strengthens the orbital overlap of Ni (3d) and O (2p) near the Fermi level, thereby regulates the phase transition and charge compensation processes with synchronized Ni and O redox. The introduction of K further adjusts the ratio of Nae and Naf sites at Na layer with enhanced structural stability and extended lattice space distance, enabling the suppression of TM dissolution, achieving a single-phase transition reaction even at a high voltage of 4.4V, and improving reaction kinetics. Consequently, KLi-NaNMO exhibits a high capacity (105 and 120 mAh g-1 in the voltage of 2-4.2V and 2-4.4V at 0.1 C, respectively) and outstanding cycling performance over 300 cycles under 4.2 and 4.4V. This work provides a dual-site doping strategy to employ synchronized TM and O redox with improved capacity and high structural stability via electronic and crystal structure modulation.

Deploying a Dipole Electric Field at the CsPbI3 Perovskite/Carbon Interface for Enhancing Hole Extraction and Photovoltaic Performance.

Carbon-based CsPbI3 perovskite solar cells without hole transporter (C-PSCs) have achieved intense attention due to its simple device structure and high chemical stability. However, the severe interface energy loss at the CsPbI3/carbon interface, attributed to the lower hole selectivity for inefficient charge separation, greatly limits device performance. Hence, dipole electric field (DEF) is deployed at the above interface to address the above issue by using a pole molecule, 4-trifluoromethyl-Phenylammonium iodide (CF3-PAI), in which the ─NH3 group anchors on the perovskite surface and the ─CF3 group extends away from it and connects with carbon electrode. The DEF is proven to align with the built-in electric field, that is pointing toward carbon electrode, which well enhances hole selectivity and charge separation at the interface. Besides, CF3-PAI molecules also serve as defect passivator for reducing trap state density, which further suppresses defect-induced non-radiative recombination. Consequently, the CsPbI3 C-PSCs achieve an excellent efficiency of 18.33% with a high VOC of 1.144V for inorganic C-PSCs without hole transporter.

Reduced-dimensional prediction method for the axial aerodynamic forces in the off-design operation of near-critical CO2 centrifugal compressors

In the high-load centrifugal compressor of near-critical CO2 (NcCO2) power-generation cycle, the overload of axial aerodynamic force causes significant harms to the structural safety and operational stability of turbomachinery components. Based on a transcritical CO2 compressor of a MWt-class simple recuperated cycle, we numerically studied the aero-thermodynamic characteristics of back-cavity leakage, and discussed the physical model of the axial aerodynamic forces in off-design operation of NcCO2 compressors. Finally, reduced-dimensional prediction method for the axial aerodynamic forces in the near-critical CO2 compressor was developed. Wherein, the Japikse's method was used to estimate the primary aerodynamic loads of centrifugal impeller, and a 1-D radial equilibrium equation with angular velocity ratio was derived to predict the thrust force acting on the impeller back disk. Furtherly, based on the near-wall distribution pattern of angular velocities and physical property of Rankine vortex, a semi-empirical model of angular velocity ratio was introduced and completed the model of back-disk force. In validation, the reduced-dimensional prediction method exhibited satisfactory accuracy with perfectly acceptable errors compared to the refined CFD simulations. Thereby, a reduced-dimensional prediction method for the axial aerodynamic forces was developed for the economical and agile analysis of NcCO2 compressors in engineering practices.