bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implementation of Artificial Compressibility Method for Steady and Unsteady Incompressible Flows Based on Finite Volume Method of Unstructured Grids
Authors: Wang Hao , Wang Jianhua , Liu Yanming 
Published: December 2022

Abstract
The development of a new computational fluid dynamics solver for simulating incompressible flows is described. Unlike traditional pressure-based solvers, the artificial compressibility method simulates both steady and unsteady states. Some classical numerical examples are used to validate the solvers. These findings show that the artificial compressibility method’s LES/DNS and steady flow simulations are competitive with the best previously reported methods. The following characteristics make this paper unique: (1) We implement the artificial compression method in OpenFOAM for the first time and show the detailed mathematical process of the algorithm so that readers can easily reproduce and improve it; (2) steady flow simulation case, the convergence time of the present method is 52% of the pressure base solver; (3) to accelerate the convergence rate of each time step to the incompressible state, the L-stable Singly Diagonal Implicit Runge-Kutta method is introduced into the pseudo-time advance, which enlarges the limit of maximum Courant number to accelerate convergence.
Sensitivity Analysis of Random Parameters for Earthquake Response of Hakka Tulou in Fujian
Authors: Yang Chunyan , Liu Qiang , Pang Shangbin 
Published: December 2022

Abstract
The seismic response analysis of the Fujian tulou structure considers the influence of six input random variables of the tulou structure. It obtains the seismic response of the apex displacement, the maximum inter-story displacement angle, and the base shear force of the tulou structure. An analysis method based on moment-independent importance measure is proposed and applied to the stochastic parameter sensitivity (importance measure) analysis of structural seismic response. The results show that the importance metric analysis method of the seismic response of the structure based on the moment-independent importance measure analysis method generates consistent outcomes with the importance measure method of the variance. However, the method in this study can better reflect the actual earthquake response of the tulou structure, and it is also an efficient method.
Application of Coupled Coordination Model in Development Evaluation of Station Area
Authors: Lv Qingwen , Shi Jianren 
Published: December 2022

Abstract
“Coupling” was originally a physical concept, and gradually extended to other professional fields due to its good applicability. Coupled coordination mathematical models and calculation methods are gradually formed and applied in empirical research. We apply the coupled coordination model derived from mathematical methods to the development evaluation of the station area. In this process, we try to improve the accuracy of the analysis results by analyzing the applicability of the model, adjusting the coefficient, and establishing the indicator system. Finally, all stations of Hangzhou Metro Line 5 are selected as the empirical objects. The analysis results show that in terms of the coupling and coordination degree between the transportation and the development of surrounding areas, the stations located in the center of the city are better than the stations at the edge of the city. However, under the influence of the development strategy and transfer attributes, the coupled coordination degree of some stations is higher than that of their neighboring stations. The station-centric transportation design and land use are beneficial to the development of station areas. In addition, the accuracy of the analysis process can be improved by using the coupled coordination model.
Lagrange’s Theorem in Group Theory
Authors: Cui Can , Gan Chenqin , Ren Changwang , Mo Zhangying 
Published: December 2022

Abstract
The structure and behavior of molecules and crystals depend on their different symmetries. Thus, group theory is an essential technique in some fields of chemistry. Within mathematics itself, group theory is very closely linked to symmetry in geometry. Lagrange’s theorem is a statement in group theory that can be viewed as an extension of the number theoretical result of Euler’s theorem. It is seen as a significant lemma for proving more complicated results in group theory. The main intention of this dissertation is to prove Lagrange’s theorem which illustrates that every quadratic irrationality has a periodic continued fraction. Conversely, every periodic continued fraction is a quadratic irrationality. The first part of this paper is the research of so-called Dirichlet groups, which are subgroups of preserving certain pairs of lines. These groups are closely related to the periodicity of sails. The structure of a Dirichlet group is induced by the structure of the group of units in order. Taking n-th roots of two-dimensional matrices using Gauss’s reduction theory will also be shown. Finally, the solutions of Pell’s equation and Lagrange’s theorem will be proved.
Seismic response characteristics and optimization analysis of large-span pipe bridge
Authors: Qi Yong-feng , Gong Ya-qi , Qin Xi 
Published: December 2022

Abstract
The large-span pipe bridge is widely applied to long-distance water diversion projects because of its large crossing capacity, strong integrity, and adaptability to complex terrain. However, under the action of an earthquake, the pipe bridge will often produce large displacement, which can lead to large deformation of the whole system and damage to the pipe bridge structure. At present, there are relatively few studies on the seismic response of such pipe bridges for water diversion, and even there is also a lack of special design specifications for pipe bridges. Combined with the construction practice of the KLH long-span pipe bridge, based on the finite element analysis, the seismic response characteristics and dynamic stabilization of the long-span pipe bridge are analyzed, so the structure optimization scheme is proposed for the key parts of the bridge. The research results can provide new ideas for the seismic design of the long-span pipe bridge.
Study on the Influence of Special Vehicle Locking Mechanism on Protective Performance
Authors: Bai Jianing , Zhou Yunbo , Zhang Ming , Cheng Zhibing , Liu Jiazhi , Tao Rui 
Published: December 2022

Abstract
In order to study the influence of various structural dimensions of the suspension floor locking mechanism on the vehicle protection performance of the special vehicle suspension floor, the finite element simulation analysis and structural optimization design of the locking mechanism are carried out. The starting load of the locking mechanism based on the occupant damage threshold was determined, the dynamic tensile loading system of the locking mechanism was designed, the accuracy of the design scheme and the finite element model was verified, and the experimental design was carried out using Latin hypercube sampling. In addition, the sensitivity analysis was carried out, the relationship between the structural size of the locking mechanism and the protective performance of the vehicle was clarified, the optimal mathematical model of the locking mechanism was established, and the Pareto solution set of the optimization model was obtained through the multi-objective genetic algorithm. The optimal design scheme of the locking mechanism was obtained by using the linear multi-criterion decision method, and the accuracy of the optimal scheme was verified by the simulation.
Analysis of Eclipsing Binary Stars and Identification of Exoplanets Using Transit Timing Variation Using data from TESS
Authors: Lo Tinfei , Fu Jiani 
Published: December 2022

Abstract
This study uses openly available TESS (Transiting Exoplanet Sky Survey) data to detect evidence for potential exoplanet transits in an eclipsing binary system. Using the Python transit light curve analysis package lightcurve, we discuss the characteristics of an eclipsing binary star’s light curve in determining the classification of a system. In addition, we also study phenomena on a light curve that indicates the existence of a potential exoplanet. Although this investigation yields null results and finds no conclusive evidence, suggesting the presence of exoplanet transits in known eclipsing binaries using TESS data, we explored in depth the physical properties of binary star system TIC 7720507, identifying strong methods for explanatory stellar research.
Frequency Division Design of Multi-Unit Moving Iron Earphone
Authors: Li Xuexia , Fan Yuchao , Lu Yuyue 
Published: December 2022

Abstract
A high-quality earphone with multiple sound-generating units and frequency-dividing circuits, with a core of sound-generating units consisting of multiple balanced armature units, aided by analog frequency-dividing circuits and an earphone shell made of light-cured resin, is designed. The whole project of physical production is realized. The analysis results of the earphone frequency response curve, which are obtained with the help of a frequency response tester, show that the production of headphones in sensitivity, frequency response curve stability, transient response, and many other aspects achieved the expected sound quality effect.
Applications of Group Theory
Authors: Tang Dongxian , Wang Zichang , Yue Bangning 
Published: December 2022

Abstract
Groups play a fundamental role in Abstract Algebra: many algebraic structures, including rings, fields, and modules, can be seen as formed by adding new operations and axioms based on groups. Researchers often use group theory to explain many kinds of phenomena. In recent years, group theory has been introduced into crystallography to further explore the macroscopic symmetry of crystals from a mathematical point of view. In this paper, the applications of group theory in crystallography and magic cubic will be discussed. Basic definitions and models of these fields are demonstrated. A finite group is a group with a finite number of elements, which are the important contents of group theory. Besides, this paper proves that n−1 elements in a n order group can completely decide the nth element and gives a method of the nth element in a commutative group of order n. The analysis suggests that the research method of group theory has an important influence on other subjects.
Experimental Study on the Influence of Heavy Mud Pollution on Tight Sandstone for Deep Wells
Authors: Liu Hui , Liu Hongtao , Qin Shiyong , Ren Dengfeng , Wen Zhiming , Liu Yuxuan 
Published: December 2022

Abstract
Heavy mud pollution tends to occur during the workover of deep tight sandstone gas wells in Tarim, resulting in a significant reduction in gas well production. In order to study the impact of heavy mud pollution in deep sandstone gas reservoirs in the Tarim Basin, the physical properties and mechanical parameters of cores before and after heavy mud pollution were tested by non-destructive testing methods such as porosity, permeability, and acoustic waves. The results show that after the matrix core is polluted by heavy mud, the overall damage of permeability is ≥60%. Low-density mud causes more damage than high-density mud. The effect of increasing displacement time on permeability damage is higher than that of increasing displacement pressure. Heavy mud has an obvious influence on matrix porosity, but with the change in displacement pressure and displacement time, the change in core porosity has no obvious regularity. After the matrix core is polluted by heavy mud, the Poisson’s ratio increases by about 70% on average, but the change in elastic modulus is small, only -1.15%−4.25%. The experimental results provide significant guidance for reservoir damage assessment of mud-contaminated wells in Tarim.
Suspension Parameters Optimization of Fast Freight Wagon Based on Low Wheel-Rail Dynamic Interactions
Authors: Li Zhenhua , Wang Chao 
Published: December 2022

Abstract
The dynamic model of fast freight wagon is established to study the effect of key parameters of the freight wagon on dynamic performance. In order to reduce the wheel-rail dynamic interactions, the parameters such as primary suspension stiffness, arm joint stiffness, and joint stiffness of the anti-yaw damper are optimized. The results indicate that the above suspension parameters have an influence on the fast freight wagon’s dynamic performance. Compared with the simulation results of the original parameters, the wheel-rail vertical force is reduced by 10%, and the wheel-rail lateral force is reduced by 42% and 38% respectively under the straight and curve conditions of the empty vehicle. The wheel-rail vertical force is reduced by 10% and 6%, and the wheel-rail lateral force is reduced by 10% and 16% respectively under the straight and curve conditions of the loaded fast freight wagon. The running stability and safety of the fast freight wagon have been improved.
Effect of intercritical quenching on microstructure and properties of DP980 steel
Authors: Fan Yixuan , Li Liejun , Peng Zhengwu , Gao Jixiang , Ren Jianping 
Published: December 2022

Abstract
The increase in the number of cars leads to an increase in energy consumption, so the trend of automotive lightweight is more and more obvious, and DP steel with its excellent strength and plastic fit, high-cost performance, and other advantages in a long time is still the main material with high strength and high performance for automobiles. The effect of quenching temperature and soaking time on the microstructure and properties of DP980 steel in the critical quenching and tempering process was studied. The results show that martensite structure occurs when the quenching temperature is 760°C, and the volume fraction of martensite is 32% when the quenching temperature is 780°C. At 720°C to 780°C, the product of strength and ductility of DP980 steel increases with the increase of quenching temperature. The focus of future work is to find the appropriate quenching temperature and the Soaking time, on the basis of reaching the strength requirements, to get the best comprehensive mechanical properties.
Preparation and photocatalytic properties of Bi2MO6 (M =W, Mo) semiconductor composite TiO2 nanowires
Authors: Shangguan Tiantian , Liu Shikai , Song Zhijian , Liu Keke , Yang Xingyuan , Li Tengfei , Deng Haonan 
Published: December 2022

Abstract
Photocatalytic degradation of pollutants using nano-TiO2 is one of the most promising strategies to solve environmental pollution problems. In this paper, we systematically studied Bi2WO6 composited TiO2 nanowires to obtain the optimum composite proportion. Moreover, the TiO2 nanowires were composited with Bi2MoO6 and Bi2WO6/ Bi2MoO6 in the optimum proportion, respectively. The results showed that the Bi2WO6/ Bi2MoO6 composited TiO2 nanowires had the best catalytic performance, and the degradation rate of methyl orange reached 78.4%, which was 3.41 times higher than that of pure TiO2 nanowires. The current work is expected to provide new ideas for the research and development of high-efficiency photocatalytic materials.
Mechanical properties and injection molding processability of glass fiber modified polylactic acid composites
Authors: Liu Weiliang , Qiu Tianyang , Wang Liang , Jiang Wei 
Published: December 2022

Abstract
In order to promote the development and application of environment-friendly plastics, a glass fiber-modified starch/polylactic acid composite was prepared by the melt extrusion method. The influence of glass fiber content on the mechanical and thermal properties of the composite was studied, and multi-objective optimization of the injection molding process was carried out with consideration of the influence of material properties. The results show that with the increase of glass fiber content from 0 to 5%, the tensile strength of the composite decreases first and then increases to an average of 60Mpa, which is about 30% higher than that of pure polylactic acid. The elastic modulus and thermal stability increase, while the elongation at break and flow rate decrease with the increase of glass fiber content. In addition, the optimized injection parameters are obtained, which can effectively reduce the warping deformation, volume shrinkage, and residual stress of injection parts. Glass fiber modified starch/polylactic acid composites show great potential in engineering application, and may provide a reference for the development and application of high-performance and green degradable materials.
Characterization of the local mechanical properties of 5083-5383 MIG welded joints
Authors: Du Zhuotong , Xu Kuilong , Wang Lei , Zhang Xianfeng , Zhang Xinyao 
Published: December 2022

Abstract
act. Due to the heat input effect, the weld seam and heat-affected zone (HAZ) are strength weakened phases in 5xxx aluminum welded joints. Therefore, the local mechanical properties of the 5xxx aluminum welded joint are worth studying for structural design. In this paper, the local mechanical properties of 5083-5383 MIG joints were studied. Through instrumented indentation and tensile tests with digital image correlation (DIC), the yield strength of the same area of the weld center, heat-affected zone, and the base metal (BM) was respectively characterized. The two methods show good consistency in the characterization of the yield strength in each region. The tensile strength of the weld zone and BM characterized by two methods also represent good consistency. The HV0.1 and HV10 Vickers hardness distribution of welded joints was studied, and the differences in the characterization of local mechanical properties of 5083-5383MIG welded joints by instrumented indentation test, tensile test with DIC and Vickers hardness are analyzed. The instrumented indentation test can be used for approximate non-destructive quantitative characterization of the local mechanical properties of 5083-5383 MIG welded joints.
Analysis of coarse stripes of alloyed hot-dip galvanized steel sheets
Authors: Xiong Taotao , Ren Jianping , Luo Chengjian , Zuo Rong 
Published: December 2022

Abstract
Zinc iron alloy hot-dip galvanized steel sheet is widely used in the automobile and household appliance industry because of its good weldability, coating property, and corrosion resistance. In the production of alloyed hot-dip galvanized steel sheets, stripe defects are often found on the surface of the strip, which affects the diffusion reaction of iron and zinc and causes the defects to be amplified. Coarse stripes are one of the main ones. In this paper, the coarse stripe defect on the surface of an alloyed hot-dip galvanized steel plate was studied, by means of the Scanning Electron Microscope and Energy Spectrum, combined with the verification of galvanizing production. The results showed that the morphology of the coarse stripes defect area on the surface of the alloyed hot-dip galvanized sheet exhibited concave-convex features, and the average iron content was 1.41% lower, compared with the defect-free area, Indicating that the streak defect region was insufficiently alloyed. It is presumed that there is oxide in the region of the streak defect. By adopting the cleaning zone and adjusting the atmosphere in the furnace, the incidence of defects was reduced by 76%, and the quality of the slab was significantly improved.
A local-resonance elastic metamaterial for the transport of wheel-rail vertical vibrations
Authors: Xu Gang-Gang , Li Ren-Sheng , Gao Xing-Lin , Wen Xiao-Dong , Liu Zi-Jiang , Sun Xiao-Wei 
Published: December 2022

Abstract
The subwavelength artificial elastic metamaterials can be used for efficient transmission of vibration energies in a tunable frequency range. A local-resonance equal-thickness elastic metamaterial plate is designed in this work. The triangular resonators in the rhombic unit cell are used to exploit the valley degeneracy of the out-of-plane locally resonant modes under hexagonal symmetry conditions. The resonators consist of high-density cores wrapped by soft elastic material, and the differences in the intrinsic frequencies produce a topological band gap caused by the double resonant effect. The reversal of the energy bands proves that the band gap has a non-trivial topology effect, i.e., there exists edge states with robustness and high transmission efficiency. This structure can be utilized in railway transportation as an advanced elastic wave medium material to improve the efficiency of sensing and harvesting the energy of vertical vibrations between vehicles and rails.
Influence of Sintering Temperature on Electrical Properties of Sb2Te3
Authors: Bai Zhiling , Qin Bingke 
Published: December 2022

Abstract
Sb2Te3-based materials are thermoelectric materials with the best performance in low-temperature regions. The preparation of antimony telluride by solid-state reaction method can shorten the production cycle and improve its electrical properties. The phase and electrical properties of the samples are characterized by XRD, SEM, Seebeck coefficient, and conductivity tester. The results show that when the holding time is 60 minutes and the sintering temperatures are 673 K, 723K, 773K, and 823 K, the resistivities of the synthesized samples are 1.68 mΩ·cm, 0.86 mΩ·cm, 0.67 mΩ·cm and 0.51mΩ·cm and the Seebeck coefficients of the synthesized samples are 99.580 μV/K, 93.633 μV/K, 96.018 μV/K and 70.152 μV/K, the maximum power factors of the samples is 1376.03 μWm−1·K−2 for sample synthesized at 773 K.
Study on firing process of silicon zinc magnesium crystal glaze
Authors: Gao Quanjin , Joenurairatana Eakachat , Simatrang Sone 
Published: December 2022

Abstract
It is complicated to control the technological conditions of silica-zinc crystalline glaze, and research on the technological conditions is an important subject in ceramic art and science. The artistic effect of silicon, zinc, and magnesium crystalline glaze is influenced by many factors, scientific and reasonable glaze composition and glaze application method are the basis of crystal formation, firing condition is the key to controlling crystal flower, and the colorant is the key factor of color presentation. This paper introduces the preparation process of crystalline art glaze of silicon, zinc, and magnesium, discusses the key factors that affect the performance of crystalline glaze and crystal formation, and determines the best glaze application method and firing technology.
The effect of the coefficient of friction between the roller and the powder on the rolling process
Authors: Yin Quan-zhong , Li Xiao-qiang , Liang Yong-ren , Li Rong , Ren Shang-yuan , Kang Zhi-Xin 
Published: December 2022

Abstract
The friction coefficient between the roller and the powder is one of the important factors affecting the rolling process. Since the friction coefficient is difficult to measure during rolling, it is usually regarded as a constant value in previous studies. However, the friction coefficient changes with the changes in process parameters such as the gap size and the rolling speed. In order to study the effect of the friction coefficient between the roller and the powder on powder rolling, the Drucker Prager Cap model for nickel powder rolling was established by ABAQUS. Firstly, the changes of contact stress (CPRESS) between the roller and the powder, the width (PE33), and relative density (SDV1) of the strip during rolling were analyzed. Then, the effect of the friction coefficient between the roller and the powder on the contact stress, the width, and the relative density of the strip was studied especially. The results show that during the rolling process, the contact stress remains basically unchanged. However, a large transverse deformation occurs on both sides of the strip, and the deformation in the middle is basically small. The relative density is greatest at the smallest seam between the rollers, and it decreases slightly after moving away from the roller, and then it remains stable. The coefficient of friction between the roller and the powder has an impact on the rolling result, in which the contact stress between the roller and the powder, the width, and the relative density of the strip will increase as the friction coefficient increases.