bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Simulation Research on Rotating Band Dynamic Engraving Process of CTA Artillery
Authors: Shi J F , Qian L F , Chen H B , Zhu Y C 
Published: May 2023

Abstract
In order to study the mechanical mechanism of the dynamic engraving process of the CTA band, the simulation model of the engraving process is established considering the friction and contact characteristics between the interfaces. The adaptive FEM-SPH coupling algorithm is used to obtain the variation law of the temperature and stress distribution of the band, the attitude of the projectile, and the dynamic engraving resistance through numerical calculation. The results show that the band undergoes plastic flow during engraving, and the surface temperature of the band is close to the melting point temperature of the material during the adiabatic engraving. The engraving process presents obvious segmented characteristics, and the initial engraving speed has an important influence on the spatial projectile attitude. The variation of dynamic engraving resistance is quite different from that of the quasi-static model, and the resistance has two ‘rising-decreasing’ processes.
Strength and Modal Analysis of a Gun Barrel under Four Different Strength Theories
Authors: Shuqiang Ge , Mingmin Liu , Feng Xie 
Published: May 2023

Abstract
The barrel with reasonable strength and vibration characteristics needs to be designed for safe and high accuracy firing. The finite element simulation analysis of a gun barrel based on the pressure-length curve load that calculated based on interior ballistic is carried out. Then the strength analysis and modal analysis of the barrel are carried out respectively. The twin shear strength theory is introduced into the design of barrel structure, and barrel elastic ultimate strength analysis method based on the twin shear strength theory is deduced in this paper. The barrel elastic ultimate strength along with the ratio of outer diameter and inner diameter according to three kinds of classical strength theory (i.e., the second, Tresca, and Mises strength theory) and twin shear strength theory were contrasted and analyzed, respectively, and the structural strength of the barrel and corresponding safety coefficient were checked and contrasted based on four different strength theories. The results show that the twin shear strength theory is the most appropriate theory for the design of the barrel. Under the same strength condition, the ratio of outer diameter to inner diameter of the barrel designed by this theory is smallest, and the weight of the barrel is the smallest. The barrel that design based on the twin shear strength theory was safer and not overweight. It also avoids the resonance frequency range and will not cause the occurrence of structure resonance phenomenon.
Analysis of the Development Direction of Small-medium Caliber Artillery
Authors: Liu Jianbin , Zhao Jianzhong , Lin Lun , Zhang Yongtao , Liu Yan 
Published: May 2023

Abstract
Abstract:This paper compares the operational mechanism of artillery to laser weapon, microwave weapon and guided missile, and summarizes the advantage and inherent shortcoming of traditional gun. By carrying out the simulation of different scenarios, the hot probability of artillery to target with different characteristics at different distance is obtained. For giving full play to the advantage of artillery and improving the operational, this paper cording the development direction of artillery technology and proposes the concept of cluster artillery, provides a new idea for the leapfrog discovery of artillery technology.
Damage Effect of Titanium Alloy by Reactive Fragment Oblique Penetration
Authors: Xiang Jing-an , Ji Peng-yuan , Zhou Sheng , Yu Qing-bo 
Published: May 2023

Abstract
The damage effect of reactive fragments on titanium alloy plates is studied through experiment and theoretical analysis. The oblique penetration process and the damage effects of the target influenced by the incident angle and velocity were analyzed. The results show that: Under the condition of 30° incidence angle, the perforation formation modes are extrusion and warping/tearing at 734m/s and 704m/s, respectively, which result to the perforation dimension at 704m/s is 1.56 times of 734m/s; The bulge is formed under the velocity of 1040m/s, at 60° and the reaction ratio of reactive fragments is insufficient. According to the damage morphology of the plate, the damage area in front of the plate can be described as five regions, and the energy density effect on the plate decreases with the increase of the incident Angle.
Latest Research Progress in Modification Technologies of PBO Fibers
Authors: Liu Q , Meng ZR , Chen XD , Xiao ZX , Peng XY 
Published: May 2023

Abstract
This paper focuses on the modification technologies of Poly (p-phenylene benzobisoxazole) (PBO) fibers and their research progress. It is found that the modification of compression resistance, surface inertia, and ultraviolet (UV) aging resistance of PBO fibers can greatly promote the wide application of PBO fibers in advanced composites. More researches are yet to be done on the new modification technologies of PBO fibers in compression resistance, and the future development direction of surface modification and UV aging resistance modification is towards realizing non-destructive modification and large-scale and industrialized online treatment.
Heat Transfer Analysis of the Tantalum-plated Barrel
Authors: Chen S Y , Chen L M , Fu J W , Li Y Z 
Published: May 2023

Abstract
Accurate calculation of temperature distribution in the barrel tube is of great importance for the barrel design. In this paper, a numerical heat conduction model of PCrNi3MoVA tube plated with tantalum coating at the inner surface is established. Based on the finite difference method, the temperature distribution of different coating schemes is calculated. The origin of rifling which is the most serious part of erosion and wear is selected as the object of study. When it comes to different coating thickness, we focused on the variation of temperature at the bore surface and the interface of Tantalum coating and steel substrate. The numerical results show that the thickness of the coating is of great significant to the temperature of the substrate.
Effects of Proportion of BF3-MEA on Curing Properties of AG-80/DDS Resin System
Authors: Wang QF , Huang CX , Chen G , Yu QQ , Wang Z , Wang ZY , Chong L , Wu ZQ , Wei HZ 
Published: May 2023

Abstract
Through differential scanning calorimeter (DSC), the systematic analysis is carried out on the issues including: the curing properties of the resin system composed of 4,4’-diaminodiphenylmethane epoxy resin (AG-80), 4,4’-diaminodiphenylsulfone (DDS) and boron trifluoride monoethylamine complex (BF3-MEA); the effect imposed by the varying content of BF3-MEA on the temperature, extent and rate of reaction; and the effect imposed by the varying DSC heating rates on the curing properties of the AG-80/DDS/BF3-MEA resin system. In the meantime, Ti0, Tp0 and Tf0 are derived, and the curing regimes of the three proportioning schemes are determined accordingly. The gel time of the AG-80/DDS/BF3-MEA resin system is measured through the gel drawing method, and the effect of the BF3-MEA content on the gel time is assessed, so as to determine that 0.7 times of the gel time shall be the pressure time for the forming of composite materials. Furthermore, tests are carried out on the mechanical properties of the resin cast and the carbon fiber composite materials prepared through the three proportioning schemes. The results have shown that when the content of BF3-MEA is 2%, the AG-80/DDS/BF3-MEA resin system outperforms the other proportioning schemes in terms of the curing process and the processability of its composite materials. Besides, the comprehensive mechanical properties of the resin cast and the carbon fiber composite are better.
Research on the application of magnetorheological fluids in artillery buffer system
Authors: Wang Kaizheng , Tian Nan , Xie Yangyang , Yang Gaowei 
Published: May 2023

Abstract
Magnetorheological fluids are an important direction in the research of smart materials. Their high damping force, wide dynamic range, high frequency response and controllable stiffness characteristics make their innovative application in the field of artillery firing technology helpful in solving many technical problems faced during artillery firing. A simulation model of the dynamics of the magnetorheological buffer system is established, the material properties of the magnetorheological fluid performance parameters actively controlled by current are investigated, and a feed-forward control of the operating current in the magnetorheological buffer system is used to analyse the artillery firing recoil and vibration under different operating conditions.The results of the study show that the adoption of a feed-forward controlled magnetorheological buffer system reduces the maximum firing recoil of the artillery and the “platform effect” of the whole recoil process is obvious, which enables active control of the artillery firing process.
Study on Reinforcing and Toughening Modification of MC Nylon
Authors: Wang ZS , Wang YS , Zhang HY , Li GC , Kong GQ , Liu ZY , Chai XM , Luan RQ , Ma HT 
Published: May 2023

Abstract
In this study, we prepared modified potassium titanate whiskers (MPTW) and aluminium oxide (Al2O3) nanoparticles-modified potassium titanate whiskers (AlNPs-MPTW), which were used as reinforcements to produce MPTW MC nylon and AlNPs-MPTW MC nylon, respectively, through in-situ polymerization. Then the thermodynamic stability and mechanical properties of these two kinds of nylon prepared and unmodified MC nylon were studied, proving that AlNPs-MPTW MC nylon possesses better performance. It was found that the prepared AlNPs-MPTW MC nylon with 0.1 wt% AlNP content and 1 wt% MPTW content delivered the optimal properties, specifically tensile strength 97±6 MPa, tensile modulus 3140±45 MPa, flexural strength 116±8 MPa, flexural modulus 3640±53 MPa, and notched impact strength 11.61 kJ/m2. The results showed that multiscale synergistic modified MC nylon possesses remarkable reinforcing and toughening effects, thereby enjoying very broad application prospects.
Design, Preparation and Characterization of Mid-infrared Low-emissivity Film
Authors: Han JL , Qiu GH , Zhang RR , Wang W , Liu YF , Yu MX 
Published: May 2023

Abstract
The rapid development of infrared detection technology requires that military targets have mid-infrared stealth performance. In this paper, a mid-infrared low-emissivity film based on one-dimensional photonic crystal structure was designed and prepared. The results showed that its reflectivity properties are improved and total thickness is reduced by optimizing the construction parameters. The thickness and refractive index of the prepared Ge film and ZnSe film were tested using IR ellipsometer. After the test results were brought into the designed structure, mid-infrared low-emissivity films with emissivity of 0.032, 0.068, 0.146, 0.203 and 0.366 were prepared by vacuum evaporation. The infrared reflectivity of the mid-infrared low-emissivity films was tested using Fourier spectrometer, and the test results are in good agreement with calculated results.
Research Progress in Smart Tunable Electromagnetic Materials
Authors: Liu YF , Zhang BQ , Wang XY , Pan SB , Han JL 
Published: May 2023

Abstract
Smart tunable electromagnetic materials can regulate and control their electromagnetic parameters by applying an external field, thus realizing the goal of smartly and actively controlling their electromagnetic properties such as response frequency, resonance range, phase, and polarization. In this paper, smart tunable electromagnetic materials are classified into conductive polymer-based tunable materials, electronic component-based tunable metamaterials, liquid crystal-based tunable materials, graphene-based tunable materials according to different tunable substrates. The relevant research progress of smart tunable electromagnetic materials is reviewed, and their application directions are summarized.
Preparation of Reference Material for Component Analysis of High Silica Glass Fiber
Authors: Zhao XG , Gong W , Zhou T , Shao HF , Deng WH , Liu YJ , Ji KJ 
Published: May 2023

Abstract
A reference material used for the component analysis of high silica glass fiber is prepared by the high-temperature melting process, a technique that can ensure the homogeneity and stability of each component. With two methods based on different principles, the components in glass fiber are accurately characterized through the joint efforts of multiple laboratories. The results show that the reference material was accurately and reliably characterized and exhibited good homogeneity and stability, and that the expanded uncertainty of the standard values was 5%-10% (k=2). Therefore, the reference material can be used to evaluate component testing methods for high silica glass fiber and calibrate related analytical instruments so that the accuracy and reliability of component characterization are ensured.
Study on Preparation, Structures, and Properties of Carbon based Magnetic Ferrite Nanofibers
Authors: Wang XY , Zhang BQ , Liu YF , Zhou GM , Pan SB 
Published: May 2023

Abstract
Ferrite nanofibers with magnetic properties are a type of functional nanomaterials developed in recent years. Compared with common bulk materials, magnetic nanofibers are of great interest in research due to their characteristics including lightweight, large specific surface area, unique magnetism and magnetocrystalline anisotropy. In this study, Polyvinyl alcohol (PVA) was used as carrier, and magnetic α-Fe2O3/C nanofibers was prepared by electrospinning method, hydrothermal synthesis and high-temperature calcination. Then, the chemical structure, micromorphology, thermal properties, crystallization products and dye adsorption properties of the magnetic composite nanofibers were characterized by FT-IR, SEM, DSC, XRD and UV-Vis. The results show that: α-Fe2O3 is well coated on the surface of PVA-based fiber carrier, and magnetic α-Fe2O3/C nanofibers have three-dimensional (3D) tubular structures. Nanofibers have a single phase structure, and α-Fe2O3 nanoparticles on the the fiber surface are well crystallized and close-packed. Magnetic α-Fe2O3/C nanofibers can achieve the fast adsorption of methylene blue, and the dye removal rate can reach 78.3% at the time of 150 min.
Effects of POSS with Different Structures on Properties of Phenylene Organic Silicone Resin-based Composites
Authors: Kong GQ , Yu QB , Wang K , Shao M , Wei HZ , Li Y 
Published: May 2023

Abstract
A variety of wave-transparent composites were prepared with multiple single-epoxy POSS and poly-epoxy POSS as modifiers, phenylene organic silicone resin as matrix, and quartz fiber as reinforcement. The effects of four epoxy POSS with different structures on the mechanical properties, dielectric properties and electromagnetic wave transmissivity of the composites were studied. Results showed that: the addition of octaepoxy POSS can significantly improve the mechanical properties of the composites, while the mechanical properties of the composites with single-epoxy POSS decline; the addition of POSS with different structures can enhance the dielectric properties of the composites; among the POSS of four structures, the glycidyl ether-based POSS can best improve the overall performance of the composites. The modified composites have a compressive strength of 140.8 MPa, bending strength of 185 MPa, and dielectric constant of about 3.0 at 8-18 GHz. Meanwhile, after comparing the effects of different glycidyl ether-based POSS additions on the properties of the composites, it is found that when the addition is 5wt%, the composites have optimal performance.
Damage Effects and Firing Strength of Carbon Fiber Composite Cases
Authors: Yu QQ , Chen G , Wang QF , Chong L , Wang ZY , Wu ZQ , Wang Z , Zheng ZC , Wei HZ 
Published: May 2023

Abstract
To examine the damage effects and firing strength of carbon fiber composite cases, this study fabricates a composite case using domestic T700 grade carbon fibers and tests the mechanical properties, static explosion performance, and firing strength of the case. Test results show that the case fragments completely and most of the fragments are burnt out with little collateral damage. The case exhibits outstanding structural properties and meets the firing strength requirements of artillery guns.
Vibration and Terahertz Wave Absorption Characteristics of Graphene Material
Authors: Wang W , Qiu GH , Han JL , Zhang RR , Guo Y , Pan SB , Yu MX 
Published: May 2023

Abstract
In this study, theoretical calculation of the molecular vibration frequency of graphene materials in the range of 0.1~10 THz was carried out using density functional theory, and the vibration mode of graphene molecules was analyzed. THz time domain spectrometer was employed to test the absorption spectra of graphene materials in the 0.2~3.5 THz frequency band, and the assignments of the absorption characteristic peaks of graphene were identified respectively. The results show that the graphene material produces resonance absorption of terahertz waves due to the interaction of intramolecular C-C at frequencies around 1.92 THz and 2.11 THz, and the calculated results are highly consistent with the experimental results.
Research progress in molecular dynamics of high-performance PBO fibers
Authors: Gao YY , Li SH , Xu JL , Wang DY , Wang RH 
Published: May 2023

Abstract
This article reviews the application and development of molecular dynamics in the field of poly(p-benzobisoxazole) (PBO) molecules, including the use of molecular dynamics simulations to calculate the theoretical Young’s modulus of PBO molecules and discuss them from the perspective of molecular theory Combine the rotational isomerism state theory with the long molecular dynamics simulation of small fragments to evaluate the limit length of the persistence vector a. The molecular dynamics calculation is used to study the molecular motion behavior of isolated rigid rod molecules such as PBO. Combining computer simulation technology and X-ray diffraction data collected by the imaging board system to analyze the crystal structure of the PBO fiber, and use molecular dynamics and dynamic modeling to establish the PBO/epoxy interface and study its performance.
Study on High-speed Transient Testing Technology using Large-area Pulsed Laser Illumination
Authors: Jia Yangyu , He Xuan , Bai Hao , Yao Qiangqiang 
Published: May 2023

Abstract
Warhead explosions are often accompanied by intense fire, harsh smoke and strong electromagnetic, which bring serious interference to the damage power testing of warheads. To address this problem, this paper presents a high-speed transient testing technique using large-area pulsed laser illumination, which can effectively remove the interference and clearly capture the diffusion process of preformed fragments and the development process of shock waves. With special software for analysis and calculation, the distribution parameters of fragments and the development process of shock wave overpressure can be obtained. The results showed that the proposed testing technique is applicable to the testing of the preformed fragments and overpressure of blast-fragmentation warheads, serving as a satisfactory solution to the damage power testing of warheads.
A Docker-based Operation and Maintenance Method for New-Generation Command and Control Systems
Authors: Yongyong Wei 
Published: May 2023

Abstract
New-generation command and control systems face a number of problems in operation and maintenance, including different programming languages used for subsystems, complex environment configuration, and diverse data formats, leading to slow system deployment, various types of managed data, and difficult operation and maintenance. This paper proposes the use of the Docker containers to wrap the system, deploy the networked control system based on the encapsulated service processes and relevant environment configuration and dependencies, and build a Docker-based operation and maintenance model for command and control systems. As for the communication between containers, the mature RocketMQ architecture is adopted for interactions based on message buses. Container migration and restart are used to improve the deployment, operation and maintenance capabilities of the entire system. The design is realized and simulated on distributed machines. This paper explains relevant concepts, design ideas, and implementation pathways.
Skills in DC electrical circuits by doctors in training
Authors: Fernando Becerra Diego , Sánchez Ana Dolores Vargas , Suárez Óscar Jardey , Mora Ley César Eduardo 
Published: May 2023

Abstract
This study describes the understanding of concepts and problem-solving skills associated with direct current electrical circuits of doctors in training at a private university in Bogotá (Colombia) in times of the COVID-19 pandemic. The study of direct current electrical circuits is conducted through a didactic sequence supported by active learning and internet resources. In the research, the Inventory of Basic Conceptions - DC Circuits (IBCDC) instrument is used. The implementation of the study was carried out in four phases: a Pre-test, a pedagogical strategy in which the theoretical approach is carried out while the real application of this thematic nucleus in the human body is mentioned, the integration of a simulation as a technological tool that allows giving continuity to the practical and theoretical character of physics and a post-test. The results invite researchers to conduct an implementation exercise in the face-to-face modality, to generate a comparative study.
The impact of Situated Learning for prospective primary teacher education and for the school
Authors: Michelini Marisa , Vidic Emanuela 
Published: May 2023

Abstract
The apprenticeship and the in-context experience of the pre-service teacher play an essential role in the construction of a professional attitude. The model developed with over 20 years of research during the Physics Education Course (PEC) in the 5 years long Master degree for Prospective Primary Teachers (PPT) at the University of Udine includes situated learning. By means of a process of reflective design and planning of educational paths, the prospective primary teachers implement Teaching Intervention Modules (TIMs) in the classroom and monitor the learning process of children. The preparation, implementation and evaluation of the TIM in real classrooms is carried out within the PEC itself and has produced an institutional interaction between the PEC coordinators and the schools. The perception of 360 in-service teachers on the quality of the implementation of the TIM was collected over three years using a questionnaire probing different perspectives. The opinions collected included those about the role and way of working of the prospective primary teacher, those about the research-based innovation of the path proposals, those about the impact in the specific classroom, those about the teaching style of the host teachers and finally those about the cooperation between schools and university.