bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Weak Point of Fluid Material Tank Based on FLUENT
Authors: Li Yongqiang , He Zhiyuan 
Published: January 2020

Abstract
In view of the high reliability requirements of fluid material tanks and the difficulty of quality inspection, FLUENT is used to construct the tank model as a set of physics variable values on a finite number of discrete points. The original continuous physical field (pressure field and velocity field, etc.) of the fluid in the time system and the space system is replaced by certain laws and principles. At the same time, an algebraic equations are established for the relationship between these finite number of discrete points, and then the basic method of finite element method is used to solve the algebraic equations, and then the relative approximation of the stress acting on the tank in the time and space systems is obtained. After a continuous accelerated simulation, the weak link of the tank is finally determined.
Stress Rupture Properties of Welded Joints of Austenitic Heat-resistant Super304H Steel at 650 °C
Authors: Li Xinmei , Zhang Zhongwen , Du Baoshuai , Suo Shuai , Li Wen 
Published: January 2020

Abstract
With the help of metalloscope, scanning electron microscope and its energy dispersive spectroscopy, this paper investigates the stress rupture properties at high temperature and microstructure changes of the welded joints of austenitic heat-resistant Super304H steel at 650 °C as well as the effects of microstructure changes on stress rupture properties by high temperature creep rupture testing. The results show that at 650 °C, the welded joint of Super304H steel has high breaking strength at elevated temperature, and the fracture position is on the base material away from the fusion line, and the fracture type is mainly a transcrystalline rupture. The microscopic process of creep rupture of Super304H steel welded joints is the nucleation and growth of the void and crack, while the large bulk Nb(C,N) is the main nucleation site of void. As the careep time increases, M23C6 on the grain boundary is also the main nucleation site of the void.
Design and Fabrication of a High Precision Constant Current Source Current Generator
Authors: Li Xiulian 
Published: January 2020

Abstract
A high precision constant current generator with current sources is designed. It adopts precise operational amplifier circuits, high precision constant current sources and FPGA chips. It can generate sine waves, triangle waves and square waves (the duty cycle is adjustable) with adjustable frequency and high precision. The output current ranges from 0 to 4000mA, which can be set as required. It has digital display and strong anti-interference ability, which can provide the current with 0.05% precision. In this paper, the working principle and design idea of the circuit are analyzed. The whole program is compiled under the environment of Lab VIEW, and the assembly, welding and debugging of the circuit are completed.
Experimental Research on Fracture Toughness and Tensile Strength of Red Sandstone under Different Moisture Content
Authors: Li Chunting , Yuan Tingwei 
Published: January 2020

Abstract
In order to study the variation and correlation of mode I fracture toughness and tensile strength of red sandstone under different moisture content conditions, Brazilian splitting and NSCB tests were carried out on the red sandstone specimens with moisture content of 0%, 1.63% and 3.33% respectively by using the CMT53 test loading system, and the test data obtained were fitted and analyzed. The test results show that: 1. The tensile strength and fracture toughness of red sandstone gradually decrease with the increase of moisture content, and the softening effect of water on red sandstone is obvious, with the reduction coefficients of 0.72 and 0.66, respectively. 2. With the increase of moisture content, the dispersion of tensile strength and fracture toughness of red sandstone increases. 3. The fitting formulas of water content and tensile strength and fracture toughness are obtained by data fitting, and the fitting correlation is relatively high. The piecewise function is used to describe the relationship between tensile strength and fracture toughness. It is convenient to estimate the fracture toughness of red sandstone through its tensile strength and it has a certain reference value for studying the relationship between tensile strength and fracture toughness of red sandstone.
Effect of calcium chloride on hydration kinetics and pore structure of hydrated tricalcium silicate
Authors: Li Qinfei , Yang Wang , Chen Heng , Hou Pengkun , Cheng Xin 
Published: January 2020

Abstract
Chemical admixtures are frequently used to regulate the setting and strength development of concrete materials. In this study, tricalcium silicate (C3S) was used as a model of the cement system, and the influence of calcium chloride, an extremely useful accelerator, on C3S hydration and the pore structure of hardened C3S paste were investigated by the combination of the techniques of differential scanning calorimetry (DSC) and the N2 adsorption (BET). The results indicated that the addition of calcium chloride would significantly shorten the pre-induction and induction periods and enhance the specific surface area and porosity of hardened C3S paste. However, the presence of CaCl2 has little effect on the pores, with a width ranging from 2.5 nm to 5 nm. DSC technique has an advantage of measuring continuously the process of C3S hydration by changes of free water in hydrated C3S.
Optimum Design of Transmission Coil for Giant Magnetostrictive Actuator
Authors: Zeng Fan , Shi Feng , Hui Ying 
Published: January 2020

Abstract
The driving coil is optimized by replacing the magnetic field with ampere turns. For a variety of wire diameter, select the appropriate trade-off between the ampere-number maximization and the power minimization when the volume is closest to its allowable value and does not exceed the maximum output current of the power supply. It is calculated that 1mm diameter coil has the minimum power consumption. Therefore, choose 1mm diameter enameled wire to wound coil.
Corrosion behavior of 316L stainless Steel under Cl− corrosion medium
Authors: Xie Jun Jun , Ningyu Heng , Sun Xu , Yang Zhan Jun 
Published: January 2020

Abstract
316L stainless steel is widely used in the fields of thermonuclear industry and petrochemical industry due to its excellent comprehensive mechanical properties and corrosion resistance. Especially in the petroleum industry, 316L stainless steel is commonly used as oil pipelines and storage tanks because of its high corrosion resistance to media such as CO2. However, 316L stainless steel will pitting in a high Cl− concentration environment, posing a potential risk to these devices. At present, there is not enough data to show that whether 316L stainless steel will bring about pitting or stress corrosion cracking under the synergistic effect of high stress and high Cl− concentration, this brings higher risks to the application and promotion of this material. In response to this phenomenon, the paper uses constant stress corrosion cracking method, and analyzes the fracture by scanning electron microscope (SEM). Researching 316L Stainless Steel corrosion behaviors and corrosion creeps in different Cl− concentration solutions.
Thermal Analysis of Double Mass Flywheel Secondary Flywheel
Authors: Yan Zhengfeng , Yin Dale , Zhou Kunpeng , Chen Lei 
Published: January 2020

Abstract
To solve the problem of thermal overload failure in dual-mass flywheel (DMF), we performed temperature field calculation and thermal analysis of the secondary flywheel in DMF. Based on the results of this analysis, we performed thermal stress analysis on the secondary flywheel. The heat transform model was built for the secondary flywheel using the thermodynamics theory. Finite element model (FEM) was built for the secondary flywheel using ABAQUS 6.12-3 software. This model was solved to obtain the distributions of the temperature field and thermal stress in the secondary flywheel after it completed five engagement-disengagement cycles. Finally, thermal shock test was conducted for the secondary flywheel on the thermal shock test bench. We performed a targeted test to verify the accuracy of thermal analysis of secondary flywheel. The analysis method can be used to optimize product parameters such as the product thickness.
Theoretical Analysis of Residual Head Velocity after the Jet Penetrating the Multi-layer Metal-Liquid Composite Structure
Authors: Zhao Changfang , Ren Jie , Kuai Tengfei , Zhou Zhitan , Zhang Kebin , Zu Xudong , Le Guigao 
Published: January 2020

Abstract
The residual head velocity after the jet penetrating a target plate is an indication of the residual penetration capability of the jet, which changes obviously with the penetration time. In this study, the residual head velocity after the jet penetrating through the n-layer metal and the n-layer liquid was deduced by using the quasi-steady penetration model theory. The influence of shock wave to the residual head velocity of jet was analyzed. The calculation results show that the residual head velocity of the jet decreases with the increase of the number of layers of the composite structure, and the shock wave obviously affects the velocity of the residual head of the jet but not very strong. According to the difference between the experimental value and the theoretical value of the jet penetrating the single-layer composite structure, a method of modifying the theoretical mathematical model by using constant C as the calibration value is proposed. The mathematical model can be extended to calculate the residual head velocity of the jet penetrating the multi-layer metal-liquid composite structure with different materials and thickness.
A SEM Study on Space Environment Effects of Carbon Nanotube Arrays
Authors: Tian Dongbo , Liu Yuming , Li Man 
Published: January 2020

Abstract
Due to their unique properties, carbon nanotubes will have great potential applications in many fields, particularly in space applications. But in development of carbon nano-materials intended for operation in aerospace, one of the most important problems is assurance of their resistance against the impact of the AO which is one of the predominant environment in space. Here we present the AO erosion effects on pure carbon nanotube arrays by SEM analysis. It is shown that the morphologies of CNT arrays are quite different from those before AO experiments. Different morphologies of CNT arrays after AO exposure are shown by SEM images. It is presented that shrinkage and crack formation of CNT arrays are caused by bombardment force.
Effect of basalt fiber on chloride ion penetration of Reactive Powder Concrete
Authors: Zhao HaiLong , Wang LuLiang , Wang Dehong , Bai Junfeng , Fan Yunting 
Published: January 2020

Abstract
In order to investigate the influence of the basalt fiber on the durability of reactive powder concrete (RPC), chloride ion penetration test of nine groups of RPC containing basalt fiber and three groups of RPC without fiber was carried out, carbonization test of one group of basalt fiber RPC was performed. The result showed that, the electrical flux of RPC without basalt fiber varied from104-120C, the chloride ion permeability was very low. The electrical flux of basalt fiber RPC was less than 100C, so the chloride ion permeability can be ignored. When water-to-binder ratio (W/B) was 0.22 and volume fraction of basalt fiber was 0.10%, the chloride ion permeation resistance of specimens was the best. The basalt fiber RPC had good carbonization resistance, and the carbonation depth was zero in 28 days.
Experimental Study of Transmission Tower Damage Detection Using Time Series Model
Authors: Guo Huiyong , Wang Zhihua 
Published: January 2020

Abstract
In order to solve damage detection problem of transmission tower, a damage index based on inter-storey stiffness and cepstral distance is presented. First, transmission tower model is established and the tower is divided into six sub-structures. Thus, we only need to identify the sub-structure location where the damaged rods are included. Then, autoregressive model is introduced, the cepstral distance between autoregressive models under damaged and undamaged states is given, and a damage index based on inter-storey stiffness and cepstral distance is proposed. Finally, the experiment of transmission tower model is conducted to evaluate the effectiveness of detecting the damaged layer of transmission tower. The analysis results of the experimental signals show that the damage index based on inter-storey stiffness and cepstral distance is an available method for damage detection of transmission tower, and the damage feature can be well extracted with the damage index.
Study on the preparation and influence of alkali metal oxides R2O on properties of microfiber glass with high water resistance
Authors: Hao Xiaotian , Wang Qingjiang , Wang Hailong 
Published: January 2020

Abstract
The microfiber glass with high water resistant was prepared by the centrifugation with synchronous water-repellent atomization spray. The influence of the alkali metal oxide Na2O/(Na2O+K2O) ratio on the fiber forming ability, chemical stability, thermal and acoustical insulation properties of the Si-Ca-Mg-Al-Fe-B multi-glass fiber system was studied by combing with the “mixed alkali effect”. It was found that when the ratio Na2O/(Na2O+K2O)=0.97, the fiber forming ability and chemical stability of the prepared microfiber glass were optimized. The transmission loss and the sound absorption coefficient are distributed at 2000Hz at a maximum of 9.1dB and 0.88. Therefore, under this paper preparation conditions the optimal Na2O and K2O distribution ratio of Si-Ca-Mg-Al-Fe-B multi-glass fiber system is 16wt% and 0.5wt%, respectively. Each prepared fiber is tightly connected together by the surface treatment of the water repellent to form a stable fiber network structure, demonstrating the feasibility of producing high water resistant microfiber glass by the centrifugation with synchronous water-repellent atomization spray in practical production applications.
Performance of Free Space Optical Communication Base on Orbital Angular Momentum with Pointing Errors
Authors: Wang Hubang 
Published: January 2020

Abstract
Due to the misalignment of the receiver, the spiral spectrum appears to be extended when the Laguerre-Gaussian beam is applied to atmospheric laser communication. This paper investigates the spiral spectrum spread of the Laguerre-Gaussian beam in the case of receiver misalignment. The analytical expression of Laguerre-Gaussian spiral spectrum under the influence of alignment error is studied by mathematical derivation and simulation. The results show that the detection probability of the original orbital angular momentum (OAM) state varies with the lateral displacement distance and the inclination angle. The bit error rate and channel capacity of each channel were studied to verify the effects of misalignment in multiple OAM communication systems.
Design of large field of view curved optical system based on ZEMAX
Authors: Zhao Yuanlin , Peng Xiangyang , Chang Shengli , Wu Wuming 
Published: January 2020

Abstract
Structural design solved the problem in the paper that the large field of view and high resolution of the compound eye optical system can not be realized simultaneously. A curved compound eye system including a 3-ring lens group is designed. The compound eye system is divided into two parts: the central sub-eye system and the edge sub-eye system. The edge sub-eye system reduced the complexity of processing because of the same lens group. In the design process, we systematically studied the field of view between the single sub-eye system and the compound eye system, and obtained the arrangement of the sub-eyes. Then, the geometrical model of a single sub-eye system stitching is presented which is based on the conjugate relations between the incident and exit window. The whole field of the compound eye system designed by this method could reach up 79.5°, the angular resolution of the center system is 0.01°, and the angular resolution of the edge system is 0.017°. Compared with traditional single aperture optical system, the image quality of edge field of view is greatly improved, and the ability to acquire the target orientation is improved. Finally, the correctness of the optical system is validated with the optical design software ZEMAX. And this research could further promote the application of compound eye imaging system.
System Design Of An Infrared Dual-band Seeker
Authors: Mao Yan-Kai , Zhao Zhen-Yu 
Published: January 2020

Abstract
Infrared imagine seeker is an important development direction of ground-to-groung ballistic missle terminal guidance technology, but it’s derection probability is vulnerable to target/background characteristic detector performance field of view and other factors. In order to improve the ability of infrared seeker to adapt to complex battlefield environment, a new design principle of infrared dual-band seeker is introduced. The whole system adopts dual band design, and uses image fusion technology to enrich the information difference between target and background features. In addition, the design of large and small dual field of view can further improve the target interception and accurate recognition and tracking ability of seeker. The working principle of infrared seeker is analyzed, and the optical design idea and image fusion method are introduced. Through index analysis and calculation, the infrared seeker meets the system requirements, which can provide reference for future ballistic missle seeker design
Low Noise VCSEL Driver for SERF Atomic Magnetometer
Authors: Wang Feihu , Hu Zhaohui , Liu Xin 
Published: January 2020

Abstract
A new type of VCSEL (Vertical-Cavity Surface-Emitting Laser) which uses Pt1000 as a temperature sensitive component and non-magnetic heating membrane as a temperature actuator is designed for SERF (Spin-Exchange Relation-Free) atomic magnetometer, which can decrease the magnetic interference produced while heating or cooling VCSEL. Therefore a low noise driver for this kind of VCSEL is necessary. A driver for the novel VCSEL is designed in this paper. The output current is adjustable from 0 to 4.5 mA, and RMS (Root Mean Square) noise of current is less than 80 nA. The operating temperature of the VCSEL is adjustable between 30-110 °C and RMS noise of temperature is less than 0.6 mK. So that it can be ensured that the VCSEL outputs a laser with stable optical power and wavelength.
Damage characteristics of VO2 films under nanosecond/picosecond laser
Authors: Lu Yuan , Feng Yunsong , Chen LeiLei , Wu Chang 
Published: January 2020

Abstract
Vanadium dioxide films were prepared by magnetron sputtering method. An experimental apparatus for laser damaging VO2 thin film was set up. Nanosecond laser and picosecond lasers were used to irradiate the thin film. The damage morphology of the thin film under these two kinds of laser was observed by metallographic microscope. Under the action of nanosecond laser, the damage of thin film is mainly thermal damage, which is mainly determined by the energy contained in the laser pulse itself, and the required damage threshold is relatively higher. The zero probability damage threshold of monopulse irradiate the film is about 0.13J/cm2.Under femtosecond laser, the damage of thin film is caused by multi-photon ionization and avalanche ionization, and the damage threshold is relatively lower. The zero probability damage threshold of monopulse irradiate the film is about 10.2m J/cm2.
Study on the effect of storage time on the quality of mutton of different brands by low-field nuclear magnetic resonance
Authors: Yang Fang , Lin Qing , Li Jiping , Huang YuYan , Xu Jianmei 
Published: January 2020

Abstract
Based on low-field magnetic resonance technology, the quality of Hainan Dong goat meat was studied at the molecular level. With the prolongation of storage time, the pH value of Hainan Dong goat meat showed an overall upward trend, and the T22 peak and T23 peak of transverse relaxation gradually shifted to the left. As the storage time prolonged, the transverse relaxation times of the peaks of samples T22 and T23 showed a decreasing trend. The T22 peak area of the water that is not easy to flow in the sample gradually decreases, while the peak area of the free water T23 gradually increases. The non-flowable water in Hainan East Goat meat was converted into free water. At the same time, the correlation between the transverse relaxation time and the pH value of the mutton quality index was analyzed, and the relationship between the quality of the mutton and the change of storage time was obtained. Finally, this paper compares Hainan Dong goat meat and Guangxi goat meat. The results show that the value of the hard-to-flow water T22 of Hainan Dong goat meat is small and the meat quality is tender. This provides data support for Hainan Dong goat meat to become the brand of lamb.
A New Single Pixel Imaging System Based on Paired Rotary Diffraction Plates
Authors: Yang Qi , Yuan Zhihao , Wang Shaowu , Lai Jianjun 
Published: January 2020

Abstract
We present a new single-pixel imaging system based on a paired rotary diffractive plates. Compared with tradition imaging system, our designed single-pixel imaging system contains simple structure and lower computational complexity. Theoretical simulation results show the single-pixel imaging system has the feasibility of thermal object imaging at wavelength λ=10.6μm, therefore which can be applied for SF6 gas imaging.
Effect of nano-TiO2 content on the flexural strength and compressive strength of dry-Mixing CDG-Slag based geopolymer paste
Authors: Wang Kai , Zha Xiaoxiong 
Published: January 2020

Abstract
In this paper, the effects of nano-titanium dioxide (TiO2) content on the 28-day flexural strength and 28-day compressive strength of Completely decomposed granite (CDG) and slag based geopolymer paste was investigated, using the dry-mixing method. The calcium hydroxide, sodium carbonate and solid sodium silicate were used as the alkali activator. The results show that with the increase of nano-titanium dioxide content increasing from 0 to 2.0%, the compressive strength and flexural strength gradually increase. In addition, the surface of geopolymer paste gradually became smooth. What’s more, the geopolymer paste microstructure was characterized by using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) Microanalysis, details of the research process and analysis are presented throughout the paper.