bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical-Chemical Properties Relationship of Pattani River and Implication for Water Quality Monitoring Study and Academic Service
Authors: Maprasit S , Pradabphetrat P , Madmanang R , Sathawong S , Boonkaew R , Suksaroj C 
Published: April 2021

Abstract
STEM learning is methodology toward providing students with cohesive and conducive learning environments that expand their knowledge in fields relating to technology, engineering, mathematics, and science. The environment learning and management is large scale impacted by the people who do the actual influencing, teaching and managing. Pattani River is considered as the important river of the southern region. Which has a length of 210 kilometers, is an important river for environment studying and developing area including academic place, industrial-agricultural area and domestic settlements across Yala, Pattani and Narathiwat province. The river consumption which should be studied and monitored to assess and prevent deterioration Especially the part of the river that passes through urban communities like Yala and Pattani Municipality. Therefore, this research aims to study the relationship between physical water quality and chemical water quality of water in the Pattani River. Classified by water sampling stations Land use and seasons The research was conducted using a single sample water collection method on the waterfront and in the middle of the Pattani River that flows through the Yala province, with 11 sampling stations. Used to analyze pH, temperature, transparency, electrical conductivity, suspended sediment and dissolved oxygen once a month from January-June 2019 and the remaining data from the Office of Natural Resources and Environment, Region 16. The results showed that the water quality varies with the season (p-value < 0.05) but does not vary with water sampling stations and land use. In the dry season, Pattani River has higher water quality than the rainy season. For areas that do not have land use, water quality is slightly better than agricultural and community areas. Chemical water quality such as pH and dissolved oxygen are related to physical water quality changes such as transparency, electrical conductivity and temperature (p-value < 0.05). Which can be used as a guideline to prevent degradation of water quality and can be developed into indicators that can be applied to communities Causing the Tambon Administrative Organization and the community to be ready to be a leader in monitoring water quality.
Effect of La-Ce Mixed Rare Earth on High Temperature Deformation Behavior of 685 Armor Steel and Its Mathematical Model
Authors: Zhang Mingyi , Gao Ping , Luo Guoping , Geng Wenyuan , Jia Xiaobin , Cao Yong 
Published: April 2021

Abstract
A thermal simulation test machine was used to conduct high-temperature compression tests on two sets of 685 test steels with and without rare earths. Through linear fitting analysis and microstructure observation, the effect of rare earths on the high-temperature deformation behavior of 685 armored steel was studied. The results show that when the deformation temperature is 1000°C, La-Ce mixed rare earth can increase the deformation resistance of steel, and the influence varies with the amount of compression deformation, while at 1100°C, the rare earth has no obvious influence on the deformation resistance of steel. After adding rare earth, the recrystallization activation energy of steel is increased by 6.78%. Mixed rare earth (La-Ce) has an inhibitory effect on the recrystallization of steel. Using Origin8.0 software for regression analysis, a mathematical model of armored steel containing rare earths is established. The model has good curve fitting characteristics, and the calculated values are basically in agreement with the experimental values.
Effects of Heat-Treatment on Microstructures and Mechanical Properties of Hot Deformed Ti-6Al-4V Alloy
Authors: Wang Qiang , Zhang Zhaohui , Zhang Shunzhong , He Jiangye 
Published: April 2021

Abstract
In this paper, Ti-6Al-4V alloy were successfully fabricated using a Spark Plasma Sintering (SPS), thermal deformation and heat treatment process. SPS sintering is divided into two steps: The first step is low-temperature molding at 600°C and 300 MPa, and the second step is thermal deformation at 800°C, with a deformation of 70%. The effects of solution treatment and aging process at temperatures above and below the β transformation point on the microstructure and mechanical properties of Ti-6Al-4V are investigated. The study found that the mechanical properties were better after treatment (900°C, 30 min+ water quenching +550°C, 4 h).
Non-Destructive X-ray Evaluation and Gap Measurement of Ceramic Armor Plate
Authors: Li Guofei , Wang Zhiwei , Yang Lin , Wang Xiaodan , Wang Lin , Xu Hai , Miao Cheng , Wu Yuchao , Guo Yiyan 
Published: April 2021

Abstract
Ceramic armors are usually made of a close-fitting periodic array of ceramic tiles, and have gaps between the tiles. The ballistic performance of the ceramic armor is highly affected by the gap width and it is important to find a way to inspect and evaluate it with no destruction. So the gaps of two ceramic armor plates, which were respectively made through hot-press vulcanization machine and autoclave system, were inspected and measured by a non-destructive X-ray evaluation method. But because of the magnification effect of the X-ray method, the measured gap width was not real. So that, it is critical to find the relation between the actual gap width with the measured. Though analysis of the magnification effect of X-ray inspection, we proposed a formula between the two, and calculated the actual gap width of the two different armor plates. It could be concluded that the autoclave method was better, with mean gap width was only 34% of that hot-press vulcanization machine made.
Energy Absorption Characteristic of Thin Monolithic Q235 Steel Plates Under Oblique Penetrating of Ogive-Nosed Projectiles
Authors: Chen Shengpeng , Pang Baojun , Cao Wuxiong , Chi Runqiang 
Published: April 2021

Abstract
In this paper, the energy absorption characteristics of single thin Q235 plates impacted by ogival-nosed projectile obliquity were modeled analytically. We offer an empirical formula involved quasi work, petal dynamic power and petal bending to describe the energy consumption of hardened projectile. The energy dissipation at ballistic limit velocity for projectile was obtained based on the empirical formula. Comparing with the energy value at ballistic limit velocity that fitted by simulation results, the analytic value agrees well with the numerical value that validated by experimental. The results show that the analytical formula can determine the energy absorbed by the thin monolithic Q235 target perforating by ogive-nosed projectile at oblique impact.
Shear Thicking and Impact Resistance Properties of STG in Flexible Protection Application
Authors: Zong Hao , Liu Zhipeng , Wei Rubin , Dong Bin , Yang Xingjuan , Zhai Wen 
Published: April 2021

Abstract
The rheological properties of shear thickening gel(STG) and its application as protective composite were studied in the paper. Upon applying a shear stress with excitation frequency from 1 Hz to 100 Hz, the storage modulus (G’) of the STG increases from 101 Pa to 105 Pa, demonstrating an excellent shear thickening effect. The reduction of temperature increases the G’min of STG, but when the temperature reaches at 50°C, the G’ curve shows a moderate slope and a gradual transition to the constant plateau value. By introducing STG into polyurethane foam and kevlar fiber with dip and dry method, successfully fabricate a nove safeguarding polymer composite. The protective performance of composite protective materials was studied by static compression experiment and drop hammer impact experiment. The addition of STG increases the impact resistance and puncture resistance of PU and kevlar by at least two times. The materials shows excellent shear stiffening effect, creep resisting and impact resistant propertie.
Influence of Modified Energetic Materials on the Protective Effect of Reactive Armor
Authors: Hao Fei , You Yang , Chen Jianshen , Zhang Jianren , Feng Xiongbo , Xu Peng , Huang He , Liu Wei , Li Mei , Guo Zhen , Zhang Wei , Li Lei 
Published: April 2021

Abstract
In order to improve the protective performance of reactive armor, the development course and present situation of reactive armor at home and abroad were described in detail, and the influencing factors of energetic materials on the protective performance of reactive armor were analyzed carefully. Finally, the protective performance of reactive armor of common type energy energetic and high energy energetic material was compared by numerical simulation and experimental verification. The results show that the protective ability of reactive armor can be improved by more than 10% compared with the common energetic materials reactive armor.
Study on the Interference of Multi-point Shaped Charge Structure on Jet
Authors: Liu Bowen , Zhou Tong 
Published: April 2021

Abstract
in order to improve the defense ability of reactive armor against shaped charge jet, a multi-point shaped charge structure is designed in the first layer of traditional explosive reaction armor, and the active passive combination method is used to interfere with the jet. The specific action process is as follows: after obtaining the signal of series warhead charge impacting explosive reactive armor. Take the initiative to detonate the shaped charge. Multiple damage elements are formed to interfere with the shaped charge jet actively. Based on LS-DYNA, the numerical simulation of multi-point shaped charge structure is carried out, and the charge structure and angle are optimized. The results show that the damage elements in different directions can be focused along the axial direction of the incoming jet by adjusting the charge structure. Changing the focal length of the converging jet can cause interference or fracture at different positions of the jet. The research results of this paper can provide reference for the design of active passive reactive armor.
Effects of Charge Type and Structure Parameters on Armor Protection Performance
Authors: Li Hao , Yin Jianping , Han Yangyang , Bi Guangjian , Qi Jiawen , Cui Hailin 
Published: April 2021

Abstract
In order to improve the reaction armor protection, this paper armours of interlayer charge and the thickness of the steel plate and charging ratio analysis, based on the reaction between armor and jet interaction, established the reactive armor and shaped charge of finite element model, using AUTODYN software, adopt the method of fluid-structure interaction for numerical simulation research. The results show that compared with other explosives, CL-20 has an ideal interference effect on jet flow. In the designed structure, the reactive armor with a steel plate thickness of 4 mm and a charge thickness of 8mm achieves the best protective performance.
Mechanical Performance of Spacecraft Protection Structure Under Hypervelocity
Authors: Bi Guangjian , Yin Jianping , Wang Zhijun , Han Yangyang , Jia Zijian 
Published: April 2021

Abstract
In order to improve the ability of the spacecraft protection system to resisted hypervelocity orbit debris, a composite double-layer honeycomb sandwich structure was proposed in the article. Four sets of models were established, through the method of controlling variables, and the SPH algorithm of the LS-DYNA finite element software was used to analysis the composite honeycomb sandwich structure. The diameter of the aluminum ball was 7mm and the velocity was 5818m/s. The results show that the residual velocity of debris cloud decreases with the increase of the cell diameter of the front-stage honeycomb. and the residual velocity of debris cloud increases with the decreases of the cell diameter of the back-stage honeycomb structure. The energy absorption effect of the composite structure was much higher than that of the traditional honeycomb structure, the remaining speed was reduced by about 64%, and the total energy absorption was increased by 77.6%.
Analysis on the Development of Active Protection System for Tanks and Armored Vehicles
Authors: Yang Likun , Xu Jiagang 
Published: April 2021

Abstract
Tanks and armored vehicles are facing increasingly diverse threats on the battlefield. Active Protection System (APS) can apparently enhance the protection capability of tanks without reducing mobility. The principle of active protection technology is introduced, and particularly the performance of radar detection subsystem and intercepting ammunition subsystem are analyzed. Moreover, the application status of APS is elaborated and the current level and main deficiency are dissected. Furthermore, the probable development trends of APS are listed.
Research Progress of Armor Protection Materials
Authors: Bao Yuguang , Gao Xiaoju , Wu Yuchao , Sun Mengyong , Li Guobin 
Published: April 2021

Abstract
With higher requirements of ballistic performance put forward by the new generation of armored vehicles, the development of new armored materials at home and abroad has made great progress. In this paper, the development status of composite ballistic armor used in armored vehicles at home and abroad is reviewed, the future development demand of composite ballistic armor used in armored vehicles is summarized, and the application prospect of new materials such as gradient functional materials, micro-laminated materials, graphene modified ceramics in armored vehicles is prospected. In order to meet the independent development needs of armored vehicles in China, it is urgent to develop new advanced lightweight protective materials with excellent performance. Only by developing new armor materials can we improve the survivability of our armored vehicles, meet the operational requirements of our weapons and equipment, and realize the synchronous development with advanced armor protection technology in the world.
Effect of Laser Beam Focusing Adjustment on the Processing Quality of Aluminum Nitride Ceramic Micro-Holes
Authors: Yang Chunyan , Hao Yun , Li Yangping , Wang Bozhe , Yuan Hai , Li Liuhui 
Published: April 2021

Abstract
The Gaussian laser beam was used to drill micro-holes with a diameter of 500μm on a 0.15mm thick aluminum nitride (AlN) ceramic. The geometry, processing quality, and surface fusion of the micro-holes were studied. The fusion recast layer at the edge of the hole is thick, the inner wall of the hole has a lot of slag, and the side wall of the laser entrance area is seriously inclined. Through spatial reshaping and focusing of Gaussian light, Bessel light with higher energy density, greater depth of focus, and smaller beam spot was achieved and used to perforate AlN ceramics. The fusion recast layer at the periphery and inner wall of the hole are both very thin, and the taper of the hole is very small. These results show that the focusing adjustment of the laser beam has a significant impact on the processing quality of AlN ceramic micro-holes.
Design of an Adaptive Lock-in Amplifier for the Terahertz System
Authors: Zhang Zhaohui , Liu Yongli , Zhu Xinyong 
Published: April 2021

Abstract
In order to extract the weak terahertz signal in the terahertz time-domain spectroscopy (THz-TDS), and to solve the problem of single amplification of the existing lock-in amplifier or manual adjustment of the amplification, a lock-in amplifier with self-adaptive adjustment function for phase and amplification is designed. Compared with the traditional lock-in amplifier, it reduces the use of electronic components such as phase shifters, modulators and summators, and reduces the development cost of the circuit. The phase shifting module and the amplification factor of the amplifying circuit are controlled by the MCU control unit and the magnitude of the received feedback signal respectively. The dynamic range of the terahertz time-domain spectroscopy system using phase and amplification adaptive lock-in amplifiers indoors can reach 70dB. The test results show that the designed lock-in amplifier can effectively improve the dynamic range of the terahertz system, and is more convenient for real-life applications.
Influence Factors of Gravitational Acceleration near the Earth
Authors: Shi Xuefeng , Wang Xingsheng , Zhang Ling , Guo Kaimin 
Published: April 2021

Abstract
Objects on the earth are subject to gravity due to universal gravitation. This paper systematically studies the influence factors, including latitude, altitude, depth inside the earth, surrounding stars, on gravitational acceleration of object near the earth. The results show that latitude has a relatively large impact on gravitational acceleration; depth and altitude have the greatest impact on gravitational acceleration. The orbit and the position of the object (dayside or nightside of the earth) have little effect on the gravitational acceleration of the object. Our work can offer reference for accurate calculation of gravity acceleration.
Tunnel Lighting Intelligent Control System Based on Ambient Light Ratio
Authors: Liu Suying , Jiao Chenfei , Zhu Chong 
Published: April 2021

Abstract
Based on the research problems of modern tunnel lighting control technology, a tunnel lighting intelligent control system based on ambient luminosity ratio is designed, which is characterized by “car close lights bright, car passing lights dark”, intelligent analysis of system failures, etc. The core technology is LED Tunnel light group brightness automatic adjustment, python data analysis, etc. The design of the core control unit of the system is based on the STC89C52 chip, which uses the numpy module in python to matrix the data in the database through the information collected by the sensor (the light intensity inside and outside the tunnel, the traffic condition of the vehicle in the tunnel, and the working condition of the tunnel lighting equipment, etc.) Level storage and use principal component analysis and other algorithms to perform a large number of calculations and processing on the obtained data. The controller generates a corresponding PWM signal to control the brightness of the LED tunnel light group to solve the problem of excessive lighting or insufficient brightness; through other controls The components exchange information, and the downstream controller performs calculation and processing according to the control instructions sent by the previous stage and the real-time signals detected by the sensors to realize the selective brightness and automatic brightness adjustment of the tunnel section lighting, and finally achieve intelligent control, energy saving and emission reduction the goal of. In addition, we use the seaborn library and matplotlib library in python to visually display the obtained tunnel lighting equipment working condition data, and send the results to the relevant road management department. This will play an important role in greatly improving the efficiency of activities such as equipment maintenance, collecting equipment work information, and optimizing the work structure of road management. To a certain extent, it is conducive to the implementation of specific work of relevant departments.
Band Structure Engineering of Black Phosphorus/Graphene/MoS2 van der Waals Heterojunctions for Photovoltaic and Optoelectronic Device Application
Authors: Zhu Wenhuan , Kong Lingwei , Long Wei , Shi Xianglei , Zhou Dayong , Sun Lijie , Zhou Lihua , Yang Guiting , Liu Xiaodong , Liu Hai , Bo Maolin , Hou Xiaoqiang 
Published: April 2021

Abstract
In this paper, we study the band structure engineering of black phosphorus/graphene/MoS2 (BP/graphene/MoS2) van der Waals heterojunctions based on ab initio simulations. The density of state and charge density of BP/MoS2, bilayer-BP/MoS2, bilayer-BP/graphene/MoS2 and graphene/bilayer-BP/MoS2 heterojunctions are also investigated. It is found that the bandgaps of these four heterojunctions are smaller than the case of single layer BP or MoS2. When graphene is inserted into or stacked upon BP and MoS2 layers, the heterojunction can obtain a minimum bandgap and a higher density of state distribution. In the differential charge density diagram, electrons over the carbon, sulfur and phosphorus atoms are lost from those corresponding parts. These investigations based on the band structure engineering of 2D van der Waals heterojunctions can provide an effective guidance to manufacture the future nanoscale high performance photovoltaic and optoelectronic devices.
Research Progress on Calendula officinalis Pb/Cd Compound Pollution
Authors: Chang Min 
Published: April 2021

Abstract
This paper analyzes the existing treatment methods of heavy metal Pb and Cd pollution, and obtains the advantages and researchable value of phytoremediation technology. The research value of the short-lived flower crop Calendula officinalis in the adsorption of heavy metal Pb and Cd compound pollution. The research value of the short-lived flower crop Calendula officinalis in the adsorption of heavy metal Pb and Cd compound pollution. The research value of the short-lived flower crop Calendula officinalis in the adsorption of heavy metal Pb and Cd compound pollution. short term crop calendula flowers in the adsorption of heavy metals Pb, Cd research value complex pollution. short term crop calendula flowers in the adsorption of heavy metals Pb, Cd research value complex pollution
Research on Multi-Source Heterogeneous Data Fusion Technology of New Energy Vehicles Under the New Four Modernizations
Authors: Zhang Fan , Yang Jing , Sun Chuan , Guo Xin , Wan Tiantian 
Published: April 2021

Abstract
In order to better adapt to the development trend of the city, new energy vehicles are widely used to fit the development concept of green transportation. As the focus of smart city development, big data is indispensable for its application in new energy vehicle guarantees, especially in maintenance and machinery guarantees. In the operation and maintenance of new energy vehicles, the application of multi-source heterogeneous data technology is extremely important. Based on this research background, the paper introduces and constructs the new energy vehicle fault feature vector of the new energy vehicle, gives a multi-source time domain frequency domain data fusion new energy vehicle fault diagnosis method, and uses the neural network to give the basic probability distribution. The evidence theory fuses the signals of each sensor to get the diagnosis result.
The key Research on Improving the Anti-jamming Performance of POF Displacement Sensor
Authors: Zhang Sen , Xue Huili 
Published: April 2021

Abstract
In weak signal detection, interference and noise have become important factors that limit and affect measurement sensitivity, accuracy, and repeatability. In order to comprehensively improve the anti-interference performance of the POF displacement sensor, it is necessary to reduce and eliminate the harmfulness of interference and noise. However, in the actual application environment, the optical signal of the measured information is often submerged in interference and noise. In order to effectively detect the weak signal under test and improve the anti-jamming performance of the entire sensor, the techniques often used include frequency domain narrowband technology, time domain averaging processing technology, discrete counting statistics technology, computer processing technology, light modulation technology, Amplification technology, correlation detection and low-pass filtering and other key technologies are the key to improving the anti-interference performance of the POF displacement sensor.