bluuebunny/crossref_metadata_2025_split huggingface dataset:
Passive Protection of Unarmoured Objects
Authors: Wiśniewski Adam 
Published: April 2021

Abstract
This article presents problems related to passive composite protection of unarmoured objects (helicopters, vehicles, etc.). It is focused on building and testing the different add-on armours (panels) protecting unarmoured objects against small-arms armour piercing projectiles (kinetic energy - KE). It has been illustrated how to increase ballistic protection of composite armours with minimum mass for unarmoured objects. The selection of appropriate materials and their parameters affects the improvement of the protection capability of these panels. The different parameters of ceramic samples (Al2O3, SiC, Ti3SiC2, B4C) which were used for the panels are presented. Panels sized of 100×100 mm contained the different types of layers, eg. polyethylene, aluminum sheet and small sized ceramics plates (50×50 mm and thickness of 6 mm, 8 mm and 9 mm), etc. The tested panels were placed in a small frame and the rear surfaces of the panels were at a distance from „witness RHA” (Rolled Homogeneous Armour). The protection capability of panels for all types of tests were defined with the use of 5.56×45 mm SS109 HC projectiles (STANAG 4569), which reference depth of penetration was DP
ref=8 mm RHA.
Research on the Effect of Rare Earth on the Structure and Impact Performance of Armor Steel
Authors: Zhang Mingyi , Gao Ping , Luo Guoping , Geng Wenyuan , Jia Xiaobin 
Published: April 2021

Abstract
In order to study the impact performance of 685 armored steel with different mischmetal content, the impact performance of the steel at room temperature and -40°C was tested, and the impact fracture morphology and microstructure were observed and analyzed. The results show that the addition of mixed rare earth La-Ce to the test steel improves the tempered martensite structure and refines the austenite grains. At the same time, the inclusions in the steel are modified, and the elongated MnS inclusions are modified. It is a spherical composite rare earth inclusion, and the size of the inclusion is reduced from 6 μ m to 2 μ m. Compared with the test steel without rare earth, the room temperature impact performance of the mixed rare earth test steel and the -40 °C low temperature impact performance are improved. When the La-Ce content is 102 × 10−6, the room temperature impact energy of the protective steel increases by 24.5%, and the low temperature impact energy at -40 °C increases by 17. 4%. The results of the shooting test showed that the protection level of rare earth-containing armored steel reached NATO Level 2.
Experimental Investigation on the Damage Characteristics for Light Armored Vehicle by Large Caliber Rifle Projectile
Authors: Li Jinming , Wang Guanghua , Yan Wenmin , Wang Shu , Mai Ruimin 
Published: April 2021

Abstract
Large-caliber multi-function rifle projectile is one of the main weapons used by the army to attack light armored vehicles. The damage of the bullet to light armored targets is not only the direct killing effect of bullets hitting the target, but also the flames and fragments formed by the penetration process. In this paper, the impact effect of a large caliber multi-functional bullet on light armored vehicles with different firing distance is studied by experiments. By reducing the charge to simulate the shooting at different distances, rifle projectiles with different speed penetrate 10 mm armor plate, and the formation process of after-effect fragment and flame is captured by high-speed photography. The flying angle, flame length and flame time can be observed from the high-speed photographic image. Through data processing, the spatial range of the after-effect fragment and flame was obtained. The research results showed that there was a positive correlation between fragment speed and penetration velocity, the after-effect fragment dispersion and the flame length are not very sensitive to the distance, and the flame size at the distance of 100 m is up to about 50% than 400 m, the flame action time at 400 m is 4.62 times that of 100 m, and the flame reached the brightest time at 400 m is 10.29 times that of 100 m.
A Numerical Simulation Study of Sandwich Structure Shield Against Invasion
Authors: Qi Jiawen , Yin Jianping , Wang Zhijun , Duan Conghui , Li Hao 
Published: April 2021

Abstract
Using ANSYS simulation software, the experimental simulation and numerical analysis of anti-12.7 mm tungsten alloy armor-piercing in different mezzanine layers of sandwich structure protection plate were carried out. The upper and lower panels of the sandwich structure are armored steel and the mezzanine is aluminum alloy. The anti-intrusion performance of the protective plate in different mezzanine structures is simulated and analyzed. The results show that the sandwich structure porous shield has excellent performance against kinetic energy, and the protective performance is better than the holeless shield plate structure under the same surface density condition. In the simulated three sets of tests, the porous shield with an aperture of 3 mm has better anti-intrusion protection performance.
Modelling of Bulging Steel-Elastomer Armour Applied Against Long-rod Projectiles
Authors: Fraś T 
Published: April 2021

Abstract
A protection concept, so-called bulging armour, applied to mitigate effects of kinetic-energy penetrators is hereby discussed basing on an experimental and numerical study. The laminated steel-elastomer armours take advantage of the rubber interlayer that deforms rapidly under an impact causing bulging of the side steel plates. Long and slender kinetic-energy projectiles made with a tungsten alloy tend to fracture disturbed by an asymmetric contact with the deforming plates. In the performed experimental study, the laminates with the natural rubber interlayer of different thicknesses are impacted by the kinetic-energy penetrators with the initial velocity above 1500 m/s. The numerical analysis accompanies the ballistic test complementing it by a detailed insight into the defeat mechanism. The performed investigation proves a protective efficiency of the discussed passive armour and explains its physical background.
Orthogonal Analysis of Linear Shaped Charges Jet Penetrating Layered Targets
Authors: Xu Bin , Liu Chunmei 
Published: April 2021

Abstract
This paper reports on the linear shaped charges (LSCs) jet penetrates into double layer spaced targets. The distance between the LSCs and the first layer target is 0.2 times width of the LSCs, the distance between the LSCs and the second layer target is 25 times width of the LSCs. The mechanism of LSCs penetrate into the double layer spaced targets causing less collateral damage in terms of jet residues has been studied by experiment and numerical simulation. After the LSCs has been crashed by detonation wave, a linear metal jet formed and penetrates into the first layer plate, then the jet is separated into jet tip and slug. The jet tip penetrates into the second layer plate and consumed, then a strip pit formed on the surface of the back plate. The slug penetrates into the second layer plate subsequently and consumed. Due to the stress concentration and tensile fracture, the second layer target is broken and less residue of jet pass it. Experiments were made and the results indicated that the numerical simulation results agreed fully with the physical principle. A verification plate was used in the experiment to test the collateral damage of residual jets. When the space between verification plate and back plate of the layered target is 500mm, both of the experimental results and simulation results show that there is no obvious damage to people. The relationship between the performance of jet and the parameters of LSCs has been analyzed by an orthogonal method (significance test and interaction effect analysis). A good teamwork should be done for all the key parameters of LSCs which can break the spaced targets with less collateral damage.
Influence of Angle on Armor Protection Performance of Thin Layer Charge Reaction
Authors: Zhou Pengfei , Li Rujiang , Liu Yang , Jia Mengye 
Published: April 2021

Abstract
In order to explore the protective effect of thin layer charge reactive armor on oblique penetration of jet, the experiment will adopt 0.8mm thin layer charge structure and change the normal Angle to study its protective ability against oblique penetration of jet. Meanwhile, finite element software ANSYS/LS-DYNA will be used to conduct numerical simulation on the process of jet and reactive armor. For 0.8 mm thin layer charge structure, it can be clearly seen that the normal Angle is from unexploded at 50 to half burst at 70 and finally to full burst at 75, and the after-effect penetration depth is also significantly reduced from 12 mm to 3 mm, with a decrease rate of 75%.
Study on Fragmentation Parameters and Similarity Relation of Natural Fragments of Counterattack Projectiles for Active Protection
Authors: Lv Juan , Kang Zhenyu , Yuan Shuqiang , Li Jingwei , Du Juan 
Published: April 2021

Abstract
The purpose of this paper is to explore the fragmentation similarity between small-size cylindrical projectiles and large-size projectiles. On the basis of the modified Payman fragmentation parameter Co, a new fragmentation parameter Cu and the projectile fragmentation similarity relation were derived. Fragmentation tests of large-size projectiles showed that the results of the number and mass distribution of natural fragments were consistent with the theoretical prediction results, which verified the correctness of the fragmentation similarity relation.
Defense Model of Intercepting a High-Velocity Long Rod by Multiple Linear Shaped Charges
Authors: Li Yishu , Cao Hequan , Yang Likun , Qin Chao 
Published: April 2021

Abstract
The interception of high-velocity long rods has always been a difficult problem in defense technology. The existing research lacks the comprehensive analysis on the relationship between the latency, interception position, intercepting velocity, aftereffect damage and other factors in the defense system. In this paper, we first established a time-space rendezvous model of the long rod intercepted by multiple Linear Shaped Charges(LSCs), and then analyzed the fracture model of the long rod, the yaw-ricochet model and the after-effect penetration model of the fractured rods. Finally, the optimal defense model was established. Based on the optimal defense model, the key parameters and their variation rules that affect the defense performance of the protection system were obtained and the key parameters were verified by numerical simulation. It was found that reducing the latency could shorten the length of the front-fractured rod and increasing the number of LSCs could also reduce the average length of the fractured rods. Shortened length of the fractured rods and various attack angles could greatly reduce the penetration depth, and then improve the defense performance. This article has an important significance for the design of the active protection system with LSCs intercepting long rods.
Comparison Study of the Fifth-Order WCNS and WENO Scheme In the Truncation Error, Dissipation and Dispersion Terms
Authors: Zhang Xu , Chen Xun , Jiang Yanqun 
Published: April 2021

Abstract
This paper makes a comparison study of the fifth-order weighted compact nonlinear scheme (WCNS) and weighted essentially non-oscillatory (WENO) scheme in the truncation error, dissipation and dispersion terms. Truncation error analysis on the WCNS shows that numerical discretization leads to dissipation and dispersion terms. The Fourier spectral analysis methods is used to analyze the dissipative and dispersive features of both schemes.
The Design of A Ku-K Band Single-Fed Wideband Circular-Polarized Patch Antenna
Authors: Zhang Meng , Huang Tao , Liu Juan , Gong Dapeng , Shi Liang , Liu Haipeng 
Published: April 2021

Abstract
In this paper, a Ku-K band single-fed broadband circularly polarized microstrip antenna is designed. The antenna is composed of rectangular dielectric substrate and corner patch. The cut-angle patch makes the microstrip antenna work in circular polarization. The impedance bandwidth of 28.7% and the axial ratio bandwidth of 15.6% are obtained by using coaxial line feeding, tangential angle feeding and multi-patch resonance. The overall thickness of the antenna structure is 1.524mm, which meets the requirements of low profile.
Astronomical Analysis on Star Exploration: A Quantitative Research on Luyten’s star based on Proper Motion and Photometric Brightness.
Authors: Qi Wenzhao 
Published: April 2021

Abstract
There are many intrinsic properties for the stars and some of them can be investigated by an astronomical way. Through an investigation on one Luyten’s star (LHS33), this paper presents one basic astronomical analysis method and result about its high proper motion, and brightness for four different filters (RC, V, Blue, Ic). It is an essential element when exploring the target star and obtaining its properties. The method used in this study is a measurement of astrometric position and photometry. All of the measurements require the original CCD (Charge-coupled Device) images obtained from the telescope and a series of software processing. The results obtained mainly are about the value of proper motion, apparent magnitude in these 4 filters above. For instance, the proper motion calculated for right ascension (RA) is 0.59 ± 0.10 arcsecs per year and for declination (Dec) is -3.70 ± 0.11 arcsecs per year. The valued calculations suggest an agreement with current published data. It verifies the correction for both operation procedure and data analysis. It gives a specific interpretation on why such the observation happened based on the quantitative analysis.
Research on Power Cable Operation Fault Alarm System Based on Big Data
Authors: Guo Yun , Xu Minhu , Zhang Jian , Tan Long , Zhang Kexin , Cao Rong 
Published: April 2021

Abstract
With the continuous development of the national economy, in order to meet the needs of industrial and agricultural production and people’s daily use of electricity, the power system has gradually developed in the direction of large capacity and high voltage. The thesis established a high-voltage cable line fault detection and lean management system based on big data technology, and gave a basic introduction to the high-voltage cable line fault diagnosis and lean management system modules. Analysed the system function modules and judgment logic based on big data technology, and the importance of the system to the cable operation and maintenance management unit to improve the management level.
Low-cost optical techniques for detecting and imaging different objects underwater
Authors: Hyiamang Churchill Osei , Guo Yinjing , Wu Qi , Zhang Jianhua , Niu Chenxi 
Published: April 2021

Abstract
The camera has been commonly used in underwater image acquisition experiments, but the image noise is high, and the distance is limited because of the underwater scattering effect. In this paper, the optical detection device of underwater objects, 520 nm continuous laser modulation by PWM pulse modulation (10 Hz, 60% space ratio), was used to scan and detect two completely different objects (such as advanced resin and green leaves). The photodetectors were used to replace cameras, collect and process the received laser echo signals, and image and display the data. The detected objects images can be visually displayed in the form of grayscale images (resolution of 143 x 62), and the corresponding effects have been discussed. In the experiment, we used a 70 cm long ultra-white glass cylinder and detected a distance of 45 cm, and the results were very consistent with the actual situation.
Analysis of the Research and Development Status and Future Development of Porcelain Insulator Fault Detection Equipment Based on a Portable Insulator Detection Device
Authors: Wang Anli 
Published: April 2021

Abstract
Fault detection of porcelain post insulators has always been the research direction of power industry. At present, the insulator testing equipment still has some defects, such as high cost, complex operation and poor effect. For the design and development of fault detection equipment for porcelain insulators, this paper will introduce the design principle and basic structure of an insulator detection equipment based on a portable insulator fault detection equipment. In this paper, combined with modern science and technology, artificial intelligence and UAV technology are combined with insulator detection work to make innovation and prospect for the future development of insulator detection equipment.
Research on High precision Yime Measurement and Analysis method Based on Oscilloscope
Authors: Yang Yang , Xia Wei , Han Lu , Ding Fenghai , Xie Jun 
Published: April 2021

Abstract
High precision time measurement technology is of great significance.It is necessary to test and analyze high precision time,whether it is engineering practice such as telecommunication,chip design,or theoretical research such as atomic physics experiment,as well as space technology such as satellite positioning,radar pulse,etc.With the help of oscilloscope,the time and delay information can be obtained with high accuracy on the premise of high accuracy on the premise of high fidelity acquisition of measured signal.In this paper,aiming at how to use oscilloscope for high-precision time test and analysis,several key factors affecting the accuracy of oscilloscope time test are analyzed,and reference methods and test examples are provided for high-precision time test.
Analysis on unbalanced compensation of star - connected Cascade H - bridge inverter
Authors: Fan Lingyun , Jiang Yunhao , Fang Sian 
Published: April 2021

Abstract
In unbalanced compensation current situation, it is necessary to take appropriate control strategies to ensure that the star connection cascade static reactive power generator of the dc side voltage balance, the commonly used methods for injecting zero sequence voltage, this paper introduce current unbalance degree to analyze the compensation ability of plant, gives the scope of compensation is derived, by means of simulation demonstrate the validity of the derived, for the star connection series H bridge the application and selection of multilevel SVG has the significance.
A PDMS Film Structured Optical fiber Ultrasonic Sensor with high Sensitivity and Wide Response Range characteristics
Authors: Li Long , Liu Shuaicheng , Hao Zhiyuan , Song Ming , Wang Guanjun , Huang Mengxing 
Published: April 2021

Abstract
This paper proposes an implementation method of the optical fiber FP pressure ultrasonic sensor with a controllable cavity length and a variable membrane, in order to effectively improve the sensitivity and response range of the optical fiber Fabry-Perot (FP) ultrasonic sensor. The optical fiber FP ultrasonic sensor with PDMS film structure proposed in this paper has obvious advantages in improving sensitivity and response range.
Anti-Interference Test Technology of Transformer Noise
Authors: Chen Wei , Cao Hao , Hu Sheng , Wu Jianli 
Published: April 2021

Abstract
In order to enhance the transformer noise test accuracy, an anti- interference method based on wavelet packet decomposition and spectral subtraction algorithm is proposed in this paper. The tested original noise signal is decomposed with the wavelet packet method. The occurring time and frequency bands of the noisy signals are observed. In these bands, the noisy signals are further processed by spectral subtraction method. Finally, the pure transformer noise is obtained with wavelet packet reconstruction. The anti-interference effects of transformer noises in the conditions of various interference sources and signal to noise ratios are simulated. The result shows that the proposed method is effective in restraining the influence of diverse burst intermittent environmental noises on the transformer noise test result.
Standing Device for Assisting Elderly People Indoors
Authors: Yang Haoming , Yu Jingle , Yang Li 
Published: April 2021

Abstract
The device is mainly to solve the problem of difficulty for the elderly indoors to get up. The coordinated cooperation of the screw rod and the electric push rod is mainly used to realize the fitting of the motion end of the device to the motion curve of the elderly when standing, thereby further improving the comfort of the elderly Make the device more adaptable. In addition, the device is also equipped with a voice drive device, and the operation of the voice control device realizes man-machine coordination.
Promote and Application of Rigid Body Moment of Inertia Experiment on College Students’ Humanistic Quality Ability
Authors: Peng Rongrong 
Published: April 2021

Abstract
In the experiment of rotational inertia of rigid body, there is often a big difference between the experimental value and the theoretical value, and the error source cannot be found accurately, which leads to the failure of the experiment. In this paper, the basic principle and formula derivation of the tri-linear pendulum method for measuring the rotational inertia of rigid body are given. The physical meaning of each character in the expression of moment of inertia and its possible influence on the accuracy of experimental results are clarified. Secondly, through the measurement of the original data, calculate the experimental results, guide students to analyze the source of error independently and put forward measures to reduce the error. Thirdly, the influence of different factors on the experimental results is analyzed, and the factors influencing the moment of inertia of rigid body are summarized. Finally, this paper discusses how to excavate physical thought, research methods and humanistic knowledge in the process of physical experiment course, and gives the measures and countermeasures to cultivate and improve the scientific and technological ability and humanistic quality of college students, so as to realize the purpose of mutual penetration of scientific knowledge and humanistic quality.
Research on the Planning and Design of Leisure Agriculture Industrial Park under the Background of Rural Revitalization
Authors: Yang Guo 
Published: April 2021

Abstract
With the increasing level of socio-economic development in China, the development of the rural economy has touched the hearts of the Central Party and the whole country, and for this reason, the strategy of rural revitalization was born. With the continuous efforts of rural management services and people in various parts of China, we have gradually explored a road of rural specialty industries that integrate agricultural cultivation, product processing, tourism and leisure experience. The paper takes the planning and design of leisure agriculture industrial park as the research object, and explains the corresponding planning and design principles. The current problems in the planning and design of some rural leisure agriculture industrial park projects in China are discussed, and the specific ideas and methods of planning and design are explored based on the research of these problems, hoping to make some contributions to the development of rural revitalization in China.
Research on the Application of Blended Teaching Mode of Computer Technology from the Perspective of Connectivism
Authors: Yu Zhijuan 
Published: April 2021

Abstract
Simmons systematically proposed the idea of connectivity in the article “Connectivism: A Learning Theory for the Digital Age”, pointing out that learning is no longer a person’s activity, but learning is a process of connecting specialized nodes and information sources. This article is to discuss the application of blended teaching mode with the help of computer technology, as well as the relationship with connectivism.