bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel quinone biosynthetic pathway illuminates the evolution of aerobic metabolism
Authors: Elling Felix J. , Pierrel Fabien , Chobert Sophie-Carole , Abby Sophie S. , Evans Thomas W. , Reveillard Arthur , Pelosi Ludovic , Schnoebelen Juliette , Hemingway Jordon D. , Boumendjel Ahcène , Becker Kevin W. , Blom Pieter , Cordes Julia , Nathan Vinitra , Baymann Frauke , Lücker Sebastian , Spieck Eva , Leadbetter Jared R. , Hinrichs Kai-Uwe , Summons Roger E. , Pearson Ann
Published: February 2025

The dominant organisms in modern oxic ecosystems rely on respiratory quinones with high redox potential (HPQs) for electron transport in aerobic respiration and photosynthesis. The diversification of quinones, from low redox potential (LPQ) in anaerobes to HPQs in aerobes, is assumed to have followed Earth’s surface oxygenation ~2.3 billion years ago. However, the evolutionary origins of HPQs remain unresolved. Here, we characterize the structure and biosynthetic pathway of an ancestral HPQ, methyl-plastoquinone (mPQ), that is unique to bacteria of the phylum
Nitrospirota
. mPQ is structurally related to the two previously known HPQs, plastoquinone from
Cyanobacteriota
/chloroplasts and ubiquinone from
Pseudomonadota
/mitochondria, respectively. We demonstrate a common origin of the three HPQ biosynthetic pathways that predates the emergence of
Nitrospirota
,
Cyanobacteriota
, and
Pseudomonadota
. An ancestral HPQ biosynthetic pathway evolved ≥ 3.4 billion years ago in an extinct lineage and was laterally transferred to these three phyla ~2.5 to 3.2 billion years ago. We show that
Cyanobacteriota
and
Pseudomonadota
were ancestrally aerobic and thus propose that aerobic metabolism using HPQs significantly predates Earth’s surface oxygenation. Two of the three HPQ pathways were later obtained by eukaryotes through endosymbiosis forming chloroplasts and mitochondria, enabling their rise to dominance in modern oxic ecosystems.
Spectroscopy of d-wave superconductors using DNA as a probing tip
Authors: Takagaki Y
Published: February 2025

Andreev reflection in DNA molecules terminated by a d-wave superconductor is investigated for demonstrating advantages in using DNA as the probe for the spectroscopy of the superconductor. DNA molecules are incorporated in the simulations using a two-leg ladder model with a simplification as constructed by homopolymers. The increase of the Andreev reflection probability at zero bias originating from the midgap surface states of d-wave superconductors appears even when the DNA molecule is coupled strongly. The zero-bias peak is enhanced by orders of magnitude when the coupling is weakened. The one-dimensional transport in DNA strands gives rise to the remarkable sensitivity in the spectroscopy, where the changes of the reflection probability caused by the midgap states are also in orders of magnitude when the voltage bias is varied and when the orientation of the d-wave symmetry is inclined with respect to the superconductor surface. The quantum interference of the transport between the two strands in DNA modifies the zero-bias increase. A narrow dip occurs at zero bias with a plateau sandwiched by two peaks in the immediate vicinity of the zero bias. The characteristics of these transmission resonances are dependent on the parameters describing the model molecules, and so the width of the resonance peaks, for instance, enables us to evaluate the strength of the inter-strand coupling.
Lasing emission from Hybrid Silver Nanowires and Zinc Oxide
Authors: Altamimi Tamim Abdullah , Wan Ahmad Kamil Wan Maryam , Bakhori Siti Khadijah Mohd , Ahmed Naser M
Published: February 2025

Silver nanowires (Ag NWs) were produced by the polyol technique at a temperature of 160°C and investigated as a random laser device by hybrid combination with zinc oxide (ZnO). A revised polyol method was employed with a short time of only 20 minutes and without an oil path. Ag NWs are extracted through centrifugation with diameters and lengths of approximately 55 nm and 1.7 μm, respectively. Subsequently, ZnO nanopowder is applied as the gain medium for investigating random lasing emission with scatterer resonance provided by the Ag NWs under different configurations: Ag NWs on top of ZnO, ZnO on top of Ag NWs, and finally a mixture of ZnO powder and Ag before applying on glass. The goal is to come up with the best configuration for hybrid Ag NWs and ZnO nanopowder, a novel combination for enhancing random lasing that is yet to be explored. The findings show the existence of Ag NWs within ZnO improves the spectral width of the lasing emission, indicating superior lasing properties. The best sample showed the lowest lasing threshold of 10 mJ/cm², which was obtained from the mixture configuration.
Biologically inspired tri-directional soft pneumatic actuators: design, modeling and multi-scenario soft robotic applications
Authors: Guo Xiaohui , Xu Defeng , Liu Hao , Li Zhaobin , Zhu Shengxin , Chen Yinuo , Fan Yao , Qian Xingyu , Wang Zhitong , Tang Yongming , Hong Weiqiang , Shu Jingfeng , Zhao Xiangchen , Hong Qi , Zhao Yunong
Published: February 2025

Currently, soft pneumatic actuators are widely used in the field of soft robotics. However, the majority of them are designed for specific application scenarios. To broaden the practical applications of a single actuator and tackle the issue of actuator versatility, this paper introduces the design of a bionic multidirectional bending actuator inspired by the tail structure of a crocodile. The actuator offers cost-effectiveness, responsiveness, adaptability, and sideways rotation capability. The research utilizes a modular approach that allows the actuator to be constructed and assembled into mechanical soft grippers, assistive gloves, and bipedal crawling robots. Based on various application scenarios, this study has designed three basic bending gaits that enable a mechanical gripper to grasp objects, unscrew bottle caps, assist the hand in grasping and placing objects, and enable the robot to crawl forward and turn, respectively. Overall, the actuators proposed in this paper are highly adaptable to a variety of applications and can reliably fulfil the required tasks.
Phonon effects, impact ionization and power conversion in Mott photovoltaic systems
Authors: Gazzaneo Paolo , Arrigoni Enrico
Published: February 2025

We analyze the effect of acoustic phonons on the photocurrent and the spectral characteristics of a simplified photovoltaic setup made of Mott insulating layers between two metallic leads with a bias voltage applied between them. We include acoustic phonons via the Migdal approximation and we use real-space Floquet dynamical mean-field theory to address the nonequilibrium Floquet steady-state. The so-called auxiliary master equation approach is employed as impurity solver. We find that impact ionization is only weakly affected by acoustic phonon dissipation at low bias voltages. For higher biases instead, the Hartree shift considerably alters the on-site energies of the Hubbard bands and suppresses the photocurrent for intermediate electron-phonon coupling strengths. Impact ionization processes play a fundamental role in enhancing the electrical output power, which decreases when electron-phonon interaction is considered.
New mean-field theory applied to antiferromagnetic spin models with geometric frustration
Authors: Oliveira Samuel , Santos Jander Pereira , Sá Barreto Francisco César
Published: February 2025

In this work, we presented a new theoretical approach based on Mean-Field Theory, employing a hybrid Hamiltonian (spin/charge) in the spin-1/2 antiferromagnetic Ising model on lattices exhibiting geometric frustration. The study was conducted using the mean-field theory derived from Bogoliubov’s inequality to obtain a generic expression for the free energy in any frustrated lattice. To validate this theoretical approach, we applied the model to both the pyrochlore and kagome lattices occupied by spin-1/2 described by antiferromagnetic Ising model. The results revealed key features of geometric frustration in the studied structures, consistent with previous results reported in the literature, such as residual entropy, the characteristic behavior of the specific heat, and the emergence of plateaus in the magnetization curves.
Dissociation of gas-phase anisole induced by low-energy electron interactions: understanding patterns of aromatic bond cleavage
Authors: Finley Jacob , Kharchilava Giorgi , Carmichael Ian , Chakraborty Dipayan , Ptasinska Sylwia
Published: February 2025

In view of elucidating the fragmentation patterns of aromatic systems induced by low-energy electron interactions, dissociative electron attachment (DEA) to gas-phase anisole was performed. Anionic fragments resulting from this DEA process were detected by a quadrupole mass spectrometer, and ion yields of those fragments as a function of incident electron energy were rendered. Our study showed the formation of CH3−, HCC−, and OCH3− fragments, suggesting that various dissociation channels proceed out of DEA to anisole. We employed density functional theory to compute thermodynamic threshold energies for each potential dissociation channel. Those theoretical calculations supported the prediction that the CH3− and OCH3− fragments form via mechanisms of single-bond cleavage; the HCC− fragments may form through two-, three-, or four-body dissociation channels that entail hydrogen transfers and the cleavage of multiple aromatic bonds. The experimental resonance energies that form the CH3−, HCC−, and OCH3− fragments were 6.0 eV, 5.8 and 9.7 eV, and 9.8 eV, respectively. Given the classification of anisole as a monosubstituted aromatic species, our results explain generalizable patterns of electron-mediated dissociation in aromatic systems.
CMB-HD as a probe of dark matter on sub-galactic scales
Authors: MacInnis Amanda , Sehgal Neelima
Published: February 2025

We show for the first time that high-resolution CMB lensing observations can probe
structure on sub-galactic scales. In particular, a CMB-HD experiment can probe out to k ∼
55 h/Mpc, corresponding to halo masses of about 108 M⊙. Over the range 0.005 h/Mpc <
k < 55 h/Mpc, spanning four orders of magnitude, the total lensing signal-to-noise ratio (SNR)
from the temperature, polarization, and lensing power spectra is greater than 1900. CMB-HD gains
most of the lensing SNR at small scales from the temperature power spectrum, as opposed to the
lensing spectrum. These lensing measurements allow CMB-HD to distinguish between cold dark matter
(CDM) and non-CDM models that change the matter power spectrum on sub-galactic scales. We also
find that CMB-HD can distinguish between baryonic feedback effects and non-CDM models due to the
different way each impacts the lensing signal. The kinetic Sunyaev-Zel'dovich (kSZ) power spectrum
further constrains non-CDM models that deviate from CDM on the smallest scales CMB-HD
measures. For example, CMB-HD can detect 1 keV warm dark matter (WDM) at 30σ, or rule out
about 7 keV WDM at 95% CL, in a ΛWDM+N
eff+ ∑ mν + m
WDM +
log10
T
AGN + A
kSZ + n
kSZ model; here T
AGN
characterizes the strength of the feedback, and A
kSZ and n
kSZ allow freedom in
the amplitude and slope of the kinetic Sunyaev-Zel'dovich power spectrum. This work provides an
initial exploration of what can be achieved with reasonable assumptions about systematic
effects. We make the CMB-HD Fisher code used here publicly available, and note that it can be
modified to use any non-CDM model that changes the matter power spectrum.
Scheme design and structural safety analysis of lifting net cage
Authors: Wang Shaomin , Ma Zhenhua , Yang Xieqiu , Bai Zemin , Qiu Yu
Published: February 2025

Deep-water cage culture can better simulate the natural growth environment of fish, improve the culture environment, and improve the yield and quality of cultured varieties. A lifting cage is a new type of fishery culture equipment, which has the advantages that ordinary deep-sea cages do not have: lifting can be realized in the case of heavy waves, wave load can be reduced, and structural safety can be improved. In this paper, according to the needs of deep-sea aquaculture, a lifting cage scheme is designed, the structural strength and stability of the cage structure under extremely typical working conditions are checked by ANSYS, and the stress concentration parts are optimized. The results show that the lifting cage platform designed in this paper has the characteristics of a simple structure and high safety factor, which provides a reference for structural design and safety evaluation of deep-sea lifting cages.
Research on reliability prediction methods for aircraft nacelle systems based on FMEA and FTA
Authors: Hua Xiaoge , Hu Ying , Li Jingjing , Cong Hao
Published: February 2025

The nacelle system, as one of the critical components of civil aircraft, is used to house the aircraft’s engine, providing structural protection, aerodynamic optimization, and facilitating ground maintenance. Its reliability is directly related to the flight safety and operational efficiency of the aircraft. With the continuous development of the national civil aviation industry, research on the reliability technology of civil aircraft nacelle systems has become particularly important, emerging as a significant research direction in the field of aeronautical engineering. This paper focuses on the reliability study of civil aircraft nacelle systems, establishing a failure FTA diagram, exploring and studying the prediction methods for reliability indicators such as DR, SR, and MTBF of civil aircraft nacelle systems, and conducting quantitative estimates of equipment-level reliability. This provides a theoretical reference for further research on the reliability and safety of civil aircraft nacelle systems in China.
Optimization study of tungsten bar rotary forging process based on deform
Authors: He Xuewen , Wang Yong , Yuan Kui
Published: February 2025

A numerical simulation of tungsten bar rotary forging was conducted using Deform 3D software. The effects of hammerhead radial feed, relative rotational speed, axial feed rate of the billet, and initial billet temperature on the forging process were investigated through an orthogonal test. The optimal parameters for tungsten bar rotary forging were determined as follows: The radial feed of the hammerhead is 1.5 mm, the relative rotational speed is 880 rpm, the axial feed rate is 6.5 m/min, and the initial billet temperature is 1550°C. Subsequently, a trial production of tungsten bar forging was performed using these optimized parameters. The results demonstrated that the samples produced with the optimized conditions exhibited excellent performance.
Optimization of auger drill design based on response surface methodology and screening techniques
Authors: Qian Zhijie , Zhou Dongcheng , Xu Zhaohuan , Hu Rongcheng , Yu Kaiyun
Published: February 2025

This paper presents a novel optimization design approach for auger drill bits, integrating Response Surface Methodology (RSM) and Screening Techniques. This combined approach not only enhances the geometric parameters and material properties but also improves drilling efficiency and wear resistance significantly over traditional design approaches. The goal is to improve the drill bit’s geometric parameters and material properties to enhance drilling efficiency, wear resistance, and processing accuracy. The study begins by defining the boundary conditions for the auger drill bit and conducting finite element analysis. Experimental design is performed using Central Composite Design (CCD). A surrogate model is generated with the Kriging model. Screening Techniques are then applied to identify the optimal solution. The results show that the optimized auger drill bit meets the stiffness and strength requirements while reducing the weight from 13.825 kg to approximately 10.1 kg. Additionally, both the maximum deformation and maximum stress are within the design standards, achieving the goal of lightweight design.
The development of a coaxial correction device for workpiece clamping is briefly discussed
Authors: Zhou Dayong , Wu Chunyan , Zhou Ling , Li Chunren , Jiao Pande , Miao Guodong
Published: February 2025

To quickly locate and improve the coaxiality of workpieces during the machining process of a common lathe, a coaxiality correction device for mounting workpieces is proposed. This device is mainly aimed at short-shaft workpieces that require multiple mounting operations during the utilization of a common lathe in emergency repair or small-batch production scenarios, which takes up a lot of time and affects the repair and processing efficiency. When using the device developed in this study to correct the coaxiality of workpieces (by making the outer surface of the workpiece tightly fit the outer surface of the bearing assembly until the bearing assembly has difficulty rotating, indicating that the workpiece has quickly aligned), not only can the coaxiality of the machined workpiece be guaranteed, but also the processing efficiency of the workpiece can be effectively improved.
Analysis of static pressure turntable bearing characteristics of tractor servo steering system
Authors: Cui Wenhao , Yu Yahui
Published: February 2025

In response to the requirement for traction sliding mode in a follow-up steering function, a follow-up steering system with static pressure support is built, using the traction conditions of the B737-800 as a case study. To achieve optimal working conditions in the new traction taxiing mode, simulations of the fluid domain and analyses of bearing characteristics are conducted, revealing the impact of system parameters on the distribution of the pressure and velocity fields of the turntable under standard operating conditions. The precise impacts of parameters like oil supply pressure and orifice diameter on the oil film-bearing performance of vertical and radial turntables are investigated in greater detail. By analyzing the distribution of oil film pressure and velocity under varying conditions, the influence of these parameters on total bearing capacity is ascertained. The performance offers a theoretical foundation and direction for the design and optimization of hydrostatic turntables, presenting significant practical value.
Research on membrane stress of diaphragm compressors based on bidirectional fluid-structure interaction
Authors: Hou Wenlong , Bao Jiahan , Chen Huaixu
Published: February 2025

Currently, in the analysis of the stress distribution on the diaphragm of a diaphragm compressor, a static analysis method is employed, assuming that the pressure on the diaphragm is uniformly distributed, which does not reflect reality. To investigate the impact of pressure distribution on diaphragm stress, a bidirectional fluid-structure interaction method is used, combined with User-Defined Functions (UDF) and dynamic mesh techniques. This method establishes a simulation model that fully simulates the compression, discharge, expansion, and suction phases of the diaphragm compressor. The pressures on the upper and lower surfaces of the diaphragm are applied to determine the maximum stress, which is then compared with the stress under uniform pressure. The results show that the pressure distribution on the diaphragm is uneven, and the maximum stress of the diaphragm calculated by the bidirectional fluid-structure interaction method is 12.73 MPa higher than that of the static analysis method. The uniform distribution pressure is used to analyze the strength and life reliability of the diaphragm, which is not high.
Study on influence of stirring intensity on the flow characteristics of solid-liquid phases in flotation machine
Authors: Liu Yangyang , Wang Xuetao , Wang Yulian
Published: February 2025

The internal flow field characteristics of the KYF flotation machine with a U tank of 50 L for solid-liquid two phases are numerically simulated by using the standard k-e turbulence model and discrete particle model based on the validation of the LDV measurement. The results show that the flow field in the flotation machine is distributed into two cycles up and down, and the fluid velocity in the separating zone is lower than that of the stirring zone. The pressure on the rotor and stator increases with the stirring intensity. Furthermore, the maximum surface pressure on the stator is higher than that on the rotor from 1.25 to 1.75 times. The investigation of the influence of stirring intensity on the flow field helps to understand the complex flow characteristics of velocity and pressure, which could guide the flotation process.
Comparative study of robotic common countersinking and robotic longitudinal-torsional composite ultrasonic countersinking experiments
Authors: Sun Lianjun , Chen Qiang , Lei Pei , Sun Hailong , Ren Guangyi , Yun Xin , Tian Jiaqiang , Liu Yulong
Published: February 2025

The robots with low stiffness are prone to chatter during countersinking, which inevitably reduces the accuracy of the countersink depth. In this paper, a method for decreasing the chatter of the robotic system is proposed by combining the robotic countersinking and longitudinal-torsional composite ultrasonic machining technology. Through the comparative study of robotic common countersinking (RCC) and robotic longitudinal-torsional composite ultrasonic countersinking (RCUC-LT) experiments, the feasibility and effectiveness of introducing ultrasonic vibration to improve the quality of robotic countersinking CFRP/Al stack have been proven from the three aspects: cutting force, hole wall quality and countersinking depth. The experimental results show that the cutting force of RCUC-LT has decreased by 35.69% than that of RCC. The hole wall quality of both CFRP and Al has been improved. Finally, for RCUC-LT, the values of countersinking depth are controlled between 1.45mm and 1.55mm, while most of the values of RCC exceed this range. Longitudinal-torsional composite ultrasonic machining technology is an effective way to improve the quality of robotic countersinking.
Effect of femtosecond laser composite texturing on tribological properties of 316LN stainless steel
Authors: Ma Junbei , Zhu Xinru , Xu Guanhua , Zhao Antao , Zhang Kaiguo , Li Yifeng , Zhang Qilin , Sang Lubin , Yang Xuefeng
Published: February 2025

As the working conditions of machining equipment become increasingly harsh, although 316LN stainless steel has good intergranular corrosion resistance and high-temperature mechanical properties, due to its relatively soft hardness, technical methods are still needed to improve its wear resistance. In this paper, after studying the mechanism of action of discrete texture and continuous texture, it is considered to be compounded. Two kinds of composite textures were designed, namely circular and grooved textures (CG) and rectangular and grooved textures (RG). The texture was prepared by femtosecond laser surface texturing technology (LST). The effects of different composite texture shapes and texture gaps on the tribological properties of materials were studied by reciprocating linear friction and wear tests. The results show that when the texture gap is 0.3mm, the composite texture has a tendency to improve the tribological properties. The friction coefficient is between 0.13-0.15, and the friction coefficient is stable, with RG exhibiting the best effect. Under the oil lubrication conditions, it is observed by scanning electron microscopy that the textured sample is mainly abrasive wear, accompanied by slight adhesive wear.
Study on the stiffness and damping characteristics of a Single-Chamber Hydro-pneumatic suspension without Hydro-pneumatic separation
Authors: Dai Li , Liu Yu , Wang Li , Wang Jiaxing
Published: February 2025

Hydro-pneumatic suspension can withstand large loads and impacts, significantly enhancing ride comfort. It is predominantly used in heavy-duty trucks, construction vehicles, and other types of vehicles that operate in complex and varied terrains. Based on the structural characteristics of the single-chamber hydro-pneumatic suspension without separation, a mechanical model is established to analyze the stiffness and damping characteristics of the suspension system. The effects of different initial pressures and volumes of nitrogen on stiffness, as well as the influence of the size of the damping hole on damping characteristics, are separately calculated. Finally, the simulation software Amesim is utilized to verify the calculation results, revealing that the stiffness characteristics and damping characteristics of suspension exhibit significant nonlinear features, and the system meets the requirements for vibration reduction, providing a valuable reference for the structural design of the suspension.
First-principles molecular dynamics simulations of the mechanical properties of Ti-Zr-Cu-Ni-X (X = Ta, Mn, V)
Authors: Jiao Haichao , Wen Mingyue , Li Zishuo , Yan Tingyi , Li Biao
Published: February 2025

To improve the research efficiency and shorten the research cycle of new Ti-Zr-Cu-Ni-based high-entropy bulk metallic glass (HE-BMGs), three HE-BMGs of Ti-Zr-Cu-Ni-X (X=Ta, Mn, V) were simulated and prepared by molecular dynamics simulation method in this paper. The radial distribution function (RDF) was used to analyze the degree of disorder in the output alloy structure. The constant strain method was used to calculate the elastic modulus of the constructed model and to infer the mechanical properties of the amorphous alloy. HE-BMGs with the addition of V elements have Young’s modulus of elasticity of up to 105 GPa and shear modulus of up to 37 GPa with the addition of Mn elements. The Poisson’s ratio is an optimum 0.34.
The influence of eccentricity and inlet water temperature on the water film pressure of water-lubricated bearings
Authors: Wang Shuaishuai , Zhu Faxin , Ten Xianbin , Dong Liangxiong
Published: February 2025

To explore the influence of eccentricity and inlet water temperature on the water film pressure of water-lubricated bearings, two different operating conditions are analyzed using ANSYS Fluent software for finite element analysis, grounded in the parameters of a laboratory small-scale underwater propeller’s water-lubricated bearings. The results indicate that, with all other conditions remaining unchanged, as the eccentricity gradually increases, the maximum positive pressure of the water film continuously increases, and the minimum negative pressure within the water film continuously decreases. Similarly, with all other conditions unchanged, as the temperature of the inlet water reduces, the maximum positive pressure within the water film continuously increases, and the minimum negative pressure of the water film continuously decreases.
Study on sensitivity analysis of blade airfoil characteristics against foreign object damage based on K-Means clustering
Authors: Yang Zijiang , Sun Tianyu , Tang Wei , Kong Weisong
Published: February 2025

In order to solve the problem of the unclear relationship between the aerodynamic characteristics of aircraft engine fan blade airfoil (such as leading edge radius and wedge angle) and its resistance to foreign body damage (FOD) and the sensitivity analysis under data redundancy conditions that cannot be achieved by traditional data analysis methods, a sensitivity analysis method based on K-means clustering was proposed. First, simulated impact tests were conducted on TC4 titanium alloy specimens using an air cannon. The step-loading test method was used to assess the High cycle fatigue (HCF) strength of the damaged specimens. Then, K-means clustering was employed to categorize the experimental data and determine the number of clusters for the test regions. Finally, in the partition divided by the K-means method, under the condition of disordered experimental data, the influence of multiple factors on the HCF of fan blades at different stages was obtained, which provides an effective data analysis method and a solid theoretical basis for the subsequent design and finalization of fan blades.
The effects of bubble defect parameters on the mechanical properties of polymer materials
Authors: Li Yong , Yao Jinshuai , Fu Yan , Miao Yanan , Chen Long , Liu Xunchen , Zheng Kai , Han Shanling
Published: February 2025

As materials science continues to advance, accurately predicting and controlling the effects of microscopic defects on the macroscopic mechanical properties of materials has become a crucial research area. Traditional experimental methods currently face challenges in providing precise characterization at the microscopic scale, particularly regarding the accurate definition and quantification of geometric parameters associated with micro-bubble defects. Consequently, there is an insufficient understanding of their effects on material mechanical properties. This study integrates CT scanning and 3D printing technologies to propose a novel method capable of precisely reproducing internal defects at the microscopic scale, enabling accurate control over defect size and spatial positioning. Additionally, a symbolic regression algorithm is employed to fit the stress-strain relationship of defective materials, exploring how varying aspect ratios and angles of defects affect polymer material degradation performance. The findings indicate that as the defect angle increases, there is a significant reduction in the stress attenuation rate within the material. Furthermore, materials with larger aspect ratios demonstrate better tensile performance and slower degradation rates across all angles. This method significantly enhances precision in controlling defect geometry and improves quantitative predictive capability regarding material performance by overcoming limitations associated with traditional approaches used to systematically characterize microscopic defects’ effects.
Research on tolerance optimization method for aircraft thin-walled components based on improved particle swarm optimization algorithm
Authors: Xue Dong , Tian Dalong , Sun Xing , Zhou Jiangtao , Du Han
Published: February 2025

The assembly accuracy of aircraft thin-walled components produced in the same batch is subject to fluctuations influenced by part tolerances and assembly processes. Significant variations in assembly precision can lead to increased assembly adjustment costs, severely affecting both efficiency and overall expenses. However, tolerance optimization that takes into account these fluctuations requires the integration of assembly deviation calculations, characterized by a high demand for large sample sizes and frequent iterative computations, which results in escalated computational costs. In this context, this paper establishes a data-driven mathematical model for tolerance optimization that comprehensively considers fluctuations in assembly accuracy, manufacturing costs, and quality losses, using a surrogate model as the core computational engine. Furthermore, to address the shortcomings of the traditional particle swarm optimization algorithm, namely, its tendency to get trapped in local optima and its insufficient local search capabilities, this study proposes an improved particle swarm optimization algorithm that integrates a chaotic local search strategy and second vibration particles. This enhanced algorithm is applied to the tolerance optimization problem of aircraft thin-walled components.
Optimum laser parameters of laser cladding WC coating on TC4 surface
Authors: Wang Di , Yi Xiaohao , Zhao Hui , Zhang Kaiyue , Du Chunyan , Qu Ning , Sun Huanming
Published: February 2025

To be able to acquire improved procedure settings, the microstructure and physical characteristics that comprise the TC4 surface are analyzed and compared. This study discusses the method of choosing laser parameters for the laser cladding of WC coating. The findings indicate that W2C, TiC, α-Ti, and WC make up the majority of the microstructure of the TC4/WC hybrid covering at 900 W, 1100 W, 1300 W, and 1500 W. TiC is mostly present as particles at low power levels, and as power increases, the coating takes on columnar and dendritic characteristics. Under 1300 W laser, the hardness of the coating increased the most, reaching 595 HV, 1.75 times the base material.
Simulation study on the passability of the soft lunar surface of the wire screen wheel
Authors: Dong Yuming , Luo Haitao , Li Yuxin , Li Dehui
Published: February 2025

In order to evaluate the passing performance of the wire mesh screen wheel designed for the lunar mobile platform, a beam element co-node method was proposed to build the finite element model of the wheel net according to its special wheel net structure. The wheel net model built by the beam element co-node method not only ensures the mesh quality and wire cross-section characteristics, but also greatly reduces the number of meshes compared with the direct meshing of the model. The lunar soil discrete element particle model and the screen wheel finite element model were set up in LS-DYNA for the joint working conditions. The screen wheel designed according to the lunar platform has a sinking amount of less than 10% of the wheel diameter and a driving torque of less than 10.2N•m under various working conditions, which proves that the wheel has good passing performance.
Simulation analysis of nonlinear consolidation in soft soil based on large-scale consolidation permeability tests
Authors: Yue Changxi , Pan Wei , Cao Yonghua , Ye Guoliang , Yu Changyi
Published: February 2025

To mitigate the influence of test size on the nonlinear compression and permeability characteristics of soft soils, this study utilized a custom-made large scale consolidation-permeation apparatus to conduct indoor experiments. The relationship between the permeability coefficient and consolidation pressure of soft clay, with the preconsolidation stress as the critical point, was obtained. A nonlinear permeability model based on growth curves was established, with relevant fitting coefficients exceeding 0.99. Finally, through the secondary development of a finite element software subroutine, the nonlinear consolidation calculations of the soil were implemented and compared with experimental results, thereby validating the reliability of the model.
Tailings sedimentation in deep-cone thickener by the numerical modelling approach
Authors: Mao Zhiran , Wang Xuetao , Wang Yulian , Chu Lianyu
Published: February 2025

A laboratory-scale deep cone thickener is investigated by a numerical modelling approach to explore the flow characteristics, thereby improving the thickener’s performance. The interaction between solid and liquid is described by the Euler-Euler model, while the turbulence is captured by the RNG k-ε model. The results indicate that when the feed concentration increases, the axial velocity and the particle concentration of overflow and underflow increase. When the feed concentration exceeds 15%, the particle concentration of overflow reaches a higher level and tends to stabilize. Furthermore, this study provides a reference for the control of feed concentration in the thickener.
The study of isothermal reduction kinetics of Cara Mine by full hydrogen reduction
Authors: Zhang Chen , Shi Haihao
Published: February 2025

The study investigated the changes in the degree of metallization of Kara iron powder with particle sizes ranging from 0.5-1.7 mm during hydrogen reduction at different temperatures (700-1000°C) and durations (0-100 min). The effective activation energy for the hydrogen reduction of Kara iron ore was calculated using the unreacted nuclear model, and the corresponding reduction kinetics equation was established to obtain the limiting link in the reduction reaction. [1] The results indicated that as the reduction temperature is increased, the degree of reduction of the iron powder increases in accordance with the aforementioned. In the low-temperature range (700~800°C), the hydrogen reduction of iron powder was controlled by diffusion reactions, while at intermediate to high temperatures (850°C), it was governed by interfacial chemical reactions. At high temperatures (900°C), the hydrogen reduction of iron powder was again dominated by diffusion reactions, with the calculated activation energy (Ea) being 73.637 kJ/mol. [2,3,4]
Non-planar slicing algorithm based on AABB and OBB bounding boxes for additive manufacturing
Authors: Liu Han , Xing Fei
Published: February 2025

To solve the geometric computation and execution efficiency problems involved in surface layering in additive manufacturing technology, a non-planar slicing algorithm using the envelope box optimization computation is proposed. First, the base mesh is offset to obtain a set of curved cross-sections. Second, collision detection is performed on the axis-aligned bounding boxes of the triangular facets in the intersection space of the model and the oriented bounding boxes of the cross-section. Finally, intersection is computed only for the pairs of triangles that pass the detection. The proposed non-planar slicing algorithm is applied to the STL model of the part. The results show that the proposed method can effectively reduce redundant computations, speed up the running time by 99.8% compared with the direct slicing method, and greatly improve the efficiency of obtaining the closed contour.
Study on rock crushing effect of uncoupled charge in different media based on numerical simulation
Authors: Duan Haixia , Da Benna , Na Chunyu , Bai Qiong
Published: February 2025

In this paper, based on the finite element numerical simulation, the influence of uncoupled charge on rock blasting effect under the condition of water and air is studied. The results show that the stress wave propagation speed of the air medium uncoupled charge is faster, and the stress fluctuation is larger in the early stage of blasting. The water medium uncoupled charge is more effective in energy transfer and crack formation. This shows that the decoupling charge of water medium can improve the energy utilization rate of explosives, reduce the vibration caused by excessive crushing, save the amount of explosives, and enhance the effect of blasting crushing.
The simulation of thermal stability in perovskite solar cells
Authors: Xue Lijuan
Published: February 2025

The purpose of this study is to study the performance changes of perovskite solar cells under fluctuating temperature conditions. The temperature of PSCs fluctuates dynamically in this environment over an extended period due to the interaction between solar radiation and the surrounding temperature. The lowest temperature is 13°C, the highest temperature can reach 63.4°C, and the thermal stress, thermal strain, and displacement are analyzed and the structure is optimized. The findings demonstrate that stress, strain, and displacement of PSCs rise dramatically with decreasing temperature when the structure temperature is below the volume reference temperature. Stress, strain, and displacement all significantly increase when the temperature rises above the reference volume temperature of the structure. At both the lowest and maximum temperatures, the optimized structure’s stress and strain values are less than those of the original structure.
Study on the erosion-corrosion behavior of copper-nickel alloys in high temperature and high humidity marine environment
Authors: Wang Kun , Tian Xuefeng , Liu Xu , Wang Gui , Deng Jianhua
Published: February 2025

This paper focuses on the study of B10 copper-nickel alloy, utilizing a self-designed tubular flow erosion device to simulate the seawater environment. Various testing techniques, including electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curve measurements, and X-ray energy dispersive spectroscopy (EDS) analysis, were employed to investigate the erosion-corrosion behavior of B10 alloy in the South China Sea seawater. Combined with the observation of corrosion morphology and compositional analysis, the influence laws of different time durations, temperatures, and flow velocities on the initial erosion-corrosion of B10 alloy were discussed. The results indicated that during erosion tests conducted in dynamic seawater with a flow velocity of 3 m/s and a temperature of 40°C for varying durations (30 minutes, 1 hour, 2 hours, and 4 hours), the highest corrosion potential was observed at 2 hours, with an oxygen (O) elemental weight percentage of 16.34%. As the erosion time increased, the oxide layers on the B10 surface gradually became denser. When erosion tests were conducted at a flow velocity of 3 m/s and an erosion time of 2 hours, but with varying temperatures (30°C, 40°C, and 50°C), the results showed that at 40°C, the erosion traces on the B10 surface were pronounced, indicating severe corrosion. At 50°C, the oxide layers on the material surface were relatively dense, accompanied by a higher number of rust blisters. The O elemental content was the lowest. In tests conducted at a temperature of 40°C, an erosion time of 2 hours, but with varying flow velocities (1 m/s, 2 m/s, 3 m/s, and 4 m/s), it was found that at a flow velocity of 3 m/s, the erosion traces were most evident, with large and numerous corrosion pits. However, at a flow velocity of 4 m/s, the oxide layers on the material surface were denser. The corrosion traces were gradually covered by a passivation film, rendering the corrosion pits less apparent.
The effect of TiC content on the microstructure and properties of CoCrMo/TiC composite coating under ultrasonic assistance
Authors: Yi Xiaohao , Sun Huanming , Zhao Hui , Gong Xun , Du Chunyan , Wang Di , Qu Ning
Published: February 2025

TC4, as a consequence of its low density, strong mechanical strength, and superior resistance to rust, is widely used in a variety of industries, including the chemical industry, aerospace, and navigation. Yet, its employment is restricted to a few particular fields due to its low hardness and low wear resistance. This work focuses on the application of laser cladding technology to manufacture CoCrMo/TiC composite paints on TC4 substrate with different TiC concentrations. The research employs XRD, OM, SEM, and EDS to examine the cladding layer’s chemical makeup and microstructure. Tribological characteristics and micro hardness were also assessed. Results indicate that the cladding layer primarily consists of the bcc phase and fcc second phase. As the TiC percentage increases, the protective coating shows a better mechanical connection to the substrate. The cladding layer is 2.03 times harder than the matrix at 30 wt.% TiC concentration. The cladding layer mostly experiences adhesive and abrasive wear, and there is a noticeable improvement in wear resistance.
Preparation of flowerlike magnetic hierarchical mesoporous iron oxide microspheres by solvothermal method without surfactants
Authors: Wu Zeqing , Long Haibo , Yu Chuanshun , Liu Kaixuan , Fu Zhongchao
Published: February 2025

For the first time, we report a novel solvothermal method using glycerol as a solvent for the controlled synthesis of flowerlike magnetic hierarchical mesoporous iron oxide microspheres (HMIMs). Flowerlike HMIMs can be prepared by using ferric citrate and urea at low solvothermal temperatures without adding any surfactants and stabilizers. The microspheres not only have magnetic properties but also have 3 nm and 31 nm mesoporous structures. The specific surface area is as high as 202 m2/g.
Effect of heat treatment on carbides, microstructure uniformity and creep property of DZ125 nickel-based alloy
Authors: Tian Ning , Dang Danping , Yu Jianwei , He Kai , Li Bin , Li Jixue , Ma Luosheng
Published: February 2025

The effect of solution temperature on the carbide evolution and creep properties of DZ125 directional solidification nickel-based alloy is investigated through solution treatment at different temperatures, mechanical property tests, and microstructure observation. The investigations show that after the low-temperature solution treatment, the dendrite/inter-dendrite regions have obvious microstructure inhomogeneity. The γ′ phase in inter-dendrite regions is coarse, while that in dendrite regions is relatively fine, and some of the massive MC-type carbides in the as-cast alloy are transformed into sieve mesh. After the high-temperature solution treatment, the coarse γ′ phase in inter-dendrite regions is eliminated, and the massive MC-type carbides are transformed into granular M23C6-type carbides to be dispersively distributed at grain boundaries and intragranular regions. The creep properties of alloys being treated in high-temperature solution are substantially improved at temperatures around 800 °C compared to those of the low-temperature solution-treated alloys. At the late creep stage, under low-temperature solid solution treatment, cracks in the alloy preferentially initiate near massive carbides at grain boundaries. Under high-temperature solid solution treatment, cracks in the alloy preferentially initiate at grain boundaries and the granular carbides act as pegs to the cracks, which hinder crack extension.
Performance of copper-based amorphous alloys for degradability of azo dyes using electrochemical methods
Authors: Bai Xiaole , Ma Guofeng
Published: February 2025

In the area of the catalytic degradability of azo dyes, amorphous alloys are increasingly attracting a wide range of interest from research scholars. The electrochemical method is characterized by cleanliness and high efficiency, but the high energy consumption of this method limits its application. However, the use of amorphous alloys as electrodes for wastewater degradation is highly efficient. In this paper, an electrochemical method was applied to degrade acid orange using copper-based amorphous alloy as electrode medium, and the effects of current density, pH value, and other factors on the efficiency of degradation were investigated. The final results show that the degradation rate reaches 99.85 % in 40 min when the pH of the initial solution is 7 and the current density is 11.9 mA/cm2. Therefore, copper-based amorphous alloy strips as electrode material have a good degradation effect on acid orange by electrochemical method and have good corrosion resistance and cyclic stability, which has a broad application prospect in degrading azo dye wastewater.
Effect of Sm content on microstructure and corrosion resistance of Mg-0.5Zn-0.4Mn-0.5Al magnesium alloy
Authors: Yao Yuan , Wang Lewen , Li Siqi , Li Mei , Jia Zheng , Fu Li
Published: February 2025

The Mg-0.5Zn-0.4Mn-0.5Al (AZM) magnesium alloy was used as the research object, and the effect of rare earth Sm on the microstructure and corrosion rate of the alloy was studied. The results show that Sm atoms combine with Mg and Al atoms and transform into Al2Sm, Al11Sm3, and Mg41Sm5 phases. As Sm content increases, the quantity and magnitude of the second phase change, while the morphology and distribution change little. Based on the findings of the hydrogen evolution, the AZM alloy rate of corrosion can be decreased by adding Sm. When the Sm content reaches 1 wt.%, the corrosion rate reaches the minimum value of 0.0205 ml/(cm2·h), and the corrosion resistance is the best.
Using a new threshold function in seismic data de-noising
Authors: Qin Feilong , Cheng Yali , Zhu Hongjin
Published: February 2025

In geological exploration, there is a large amount of unpredictable noise interference in seismic data that needs to be removed. The traditional soft and hard threshold methods have been widely used in seismic data de-noising, but they have some defects such as discontinuity and constant deviation at the threshold, which leads to poor de-noising effects. Therefore, this paper introduces the weighted average idea into the traditional threshold methods and an improved threshold function based on seismic data de-noising is proposed. In the new method, this paper explores the layers of wavelet decomposition, establishes an optimal wavelet basis, and selects a variability threshold according to the number of decomposition layers instead of a fixed constant, avoiding the elimination of some effective signals. The de-noising effect of new method is evaluated by using two evaluation indicators: signal-to-noise ratio abbreviated as SNR and root mean square error abbreviated as RMSE. Finally, the designed new method is applied to actual mining areas for seismic data de-noising. The results show that the new method can effectively remove noise from seismic data and the texture of seismic profile after noise reduction is clear and smooth. Compared with traditional threshold methods, the new method has better de-noising performance.