bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational modeling of a generative grammar for clitic order in River Plate Spanish
Authors: Koza Walter , Mare María
Published: March 2023

The order of clitics (CLs) in Romance languages has been studied in depth by many scholars since Perlmutter’s first approach. This author points out that person and case features impose a filter that results in the following pattern in Spanish: Se- II- I- IIIdat- IIIacc. This pattern has been revisited because it is not restrictive enough: it gives rise to impossible sequences. In this context, the goal of this work is to define a pattern of morphosyntactic features for River Plate Spanish clitics, and an ordering pattern, with the purpose of developing a computational model for an automatic analysis of this phenomenon. This kind of analysis is justified because the algorithm output shows the degree of success of the descriptive proposal. To this end, we use NooJ, a linguistic development environment that has diverse tools. The computational modeling involves two stages: (i) the creation of an electronic dictionary and (ii) the creation of a computational grammar. The algorithm developed can generate all correct sentences conformed by Nominative Pronoun + CL + CL + Verb, Non-Finite Verb-CL-CL and Imperative Verb-CL-CL, and it can recognize these kinds of expressions in written text assigning the correct semantic labels. With these results, we conclude that our descriptive proposal is adequate for the analysis of sequences of clitics in River Plate Spanish.
Quantum Stirling heat engine with squeezed thermal reservoir
Authors: Papadatos Nikolaos
Published: March 2023

We analyze the performance of a quantum Stirling heat engine (QSHE), using a two-level system and a harmonic oscillator as the working medium, that is in contact with a squeezed thermal reservoir and a cold reservoir. First, we derive closed-form expressions for the produced work and efficiency, which strongly depend on the squeezing parameter r
h. Then, we prove that the effect of squeezing heats the working medium to a higher effective temperature, which leads to better overall performance. In particular, the efficiency increases with the degree of squeezing, surpassing the standard Carnot limit when the ratio of the temperatures of the hot and cold reservoirs is small. Furthermore, we derive the analytical expressions for the efficiency at maximum work and the maximum produced work in the high and low temperature regimes, and we find that at extreme temperatures the squeezing parameter r
h does not affect the performance of the QSHE. Finally, the performance of the QSHE depends on the nature of the working medium.
Flat band in hole-doped transition metal dichalcogenide observed by angle-resolved photoemission spectroscopy
Authors: Wang Zilu , Dong Haoyu , Zhou Weichang , Cheng Zhihai , Wang Shancai
Published: March 2023

Layered transition metal dichalcogenides (TMDCs) gained widespread attention because of their electron-correlation-related physics, such as charge density wave (CDW), superconductivity, etc. In this paper, we report the high-resolution angle-resolved photoemission spectroscopy (ARPES) studies on the electronic structure of Ti-doped 1T-Ti
x
Ta1–x
S2 with different doping levels. We observe a flat band that originates from the formation of the star of David super-cell at the x = 5% sample at the low temperature. With the increasing Ti doping levels, the flat band vanishes in the x = 8% sample due to the extra hole carrier. We also find the band shift and variation of the CDW gap caused by the Ti-doping. Meanwhile, the band folding positions and the CDW vector
q

CDW are intact. Our ARPES results suggest that the localized flat band and the correlation effect in the 1T-TMDCs could be tuned by changing the filling factor through the doping electron or hole carriers. The Ti-doped 1T-Ti
x
Ta1–x
S2 provides a platform to fine-tune the electronic structure evolution and a new insight into the strongly correlated physics in the TMDC materials.
Phase behavior and percolation in an equilibrium system of symmetrically interacting Janus disks on the triangular lattice
Authors: Zhang Xixian , Hu Hao
Published: March 2023

A Janus particle has two distinct areas on its surface. Denoting the two areas as P (patch) and N (nonpatch), when two particles come close to each other, the strength of the PP interaction is usually different from that of the NN interaction. Recently the interplay between a rotational-symmetry-breaking continuous phase transition and percolation has been explored for an equilibrium system of asymmetrically interacting (i.e., attractive PP interaction, zero NN and PN interactions) Janus disks on the triangular lattice. By Monte Carlo simulation and finite-size scaling analysis, in this work we study an equilibrium system of symmetrically interacting (i.e., attractive PP and NN interactions with the same strength, zero PN interaction) Janus disks on the same lattice. By definition, the phase diagram in the T–θ plane is symmetric for systems with patch sizes θ below and above 90°. We determine the phase diagram and compare it with that of the asymmetric system. Similar to the latter system, for 60° < θ < 90°, a rotational-symmetry-breaking continuous phase transition and an anisotropic percolation transition are found in the symmetric system, though the transition points in the two systems are quite different. Phase crossover curves are found to be different, e.g., a continuous varying crossover line extends between θ = 0° and 90° for the symmetric model; and in the range 0° < θ ≤ 30°, along the crossover lines of the two models, the trends of 1/T vs. θ are opposite in the two systems. We understand the latter by analytically solving the models with two particles in 0° < θ ≤ 30°. These results are helpful for understanding close-packed systems of Janus disks with more complex interactions.
Direct Kerr-lens mode-locked Tm:LuYO3 ceramic laser
Authors: Ling 令 Weijun 维军 , Xue 薛 Jingwen 婧雯 , Yang 杨 Jinfang 金芳 , Wang 王 Chong 翀 , Du 杜 Xiaojuan 晓娟 , Wang 王 Wenting 文婷 , Zhang 张 Mingxia 明霞 , Lu 路 Feiping 飞平 , Li 李 Xiangbing 向兵 , Dong 董 Zhong 忠
Published: March 2023

A direct Kerr-lens mode-locked Tm:LuYO3 ceramic laser without the aid of any mode-locked starting element is reported for the first time. A pulse duration as short as 259 fs and a maximum average output power of 326 mW are obtained at a repetition rate of 97.1 MHz. The corresponding optical spectrum centered at 2053 nm exhibits a bandwidth of 19.8 nm, which indicates the presence of nearly Fourier transform-limited pulses. Such a Kerr-lens mode-locked Tm:LuYO3 ceramic laser is a promising ultrashort pulse source, with both the excellent laser characteristics of Tm:LuYO3 and the high-power 790 nm laser diode pumping scheme.
A cryogenic radio-frequency ion trap for a 40Ca+ optical clock
Authors: Zeng 曾 Mengyan 孟彦 , Huang 黄 Yao 垚 , Zhang 张 Baolin 宝林 , Ma 马 Zixiao 子晓 , Hao 郝 Yanmei 艳梅 , Hu 胡 Ruming 如明 , Zhang 张 Huaqing 华青 , Guan 管 Hua 桦 , Gao 高 Kelin 克林
Published: March 2023

A liquid-nitrogen cryogenic 40Ca+ optical clock is presented that is designed to greatly reduce the blackbody radiation (BBR) shift. The ion trap, the electrodes and the in-vacuum BBR shield are installed under the liquid-nitrogen container, keeping the ions in a cryogenic environment at liquid-nitrogen temperature. Compared with the first design in our previous work, many improvements have been made to increase the performance. The liquid-nitrogen maintenance time has been increased by about three times by increasing the volume of the liquid-nitrogen container; the trap position recovery time after refilling the liquid-nitrogen container has been decreased more than three times by using a better fixation scheme in the liquid-nitrogen container; and the magnetic field noise felt by the ions has been decreased more than three times by a better design of the magnetic shielding system. These optimizations make the scheme for reducing the BBR shift uncertainty of liquid-nitrogen-cooled optical clocks more mature and stable, and develop a stable lock with a narrower linewidth spectrum, which would be very beneficial for further reducing the overall systematic uncertainty of optical clocks.
Theoretical uncertainties count: parity violating asymmetry and dipole polarizability in 208Pb
Authors: Roca-Maza Xavier , Nazarewicz Witold , Reinhard Paul-Gerhard
Published: March 2023

In this contribution, we overview a recent theoretical work [1] where a sound statistical and systematic analysis based on nuclear Energy Density Functionals of the parity violating asymmetry and dipole polarizability in 208Pb has been presented. Based on our results, we predict a neutron skin thickness in 208Pb which barely overlaps the lower-edge of the estimation presented in [2] and is consistent with much of the previous work.
Investigation of Λ-Hypernuclei within the Equation of Motion Phonon Method
Authors: Petrellis D. , Veselý P. , De Gregorio G. , Knapp F. , Bydžovský P. , Denisova D. , Pokorný J. , Skoupil D. , Lo Iudice N.
Published: March 2023

A formulation of the equations of motion phonon method (EMPM) suited for hypernuclei is outlined and illustrated through an application to

B

∧

12

. A self-consistent calculation using realistic modern potentials is performed using a multiphonon basis which enables us to couple the Λ-particle-proton-hole (pΛ - h) Tamm-Dancoff (TDΛ) states to the excitations of the nuclear core. The impact of such a coupling on the energy levels and on the electroproduction cross section of

B

∧

12

suggests that complex configurations accounting for the excitation of the nuclear core are needed for approaching the experimental data.
Analysis of two-particle transfer reaction in the 18O+40Ca and 20Ne+116Cd collisions
Authors: Ferreira J. L. , Lubian J. , Cardozo E. N. , Cappuzzello F. , Cavallaro M. , Carbone D.
Published: March 2023

Two-neutron and two-proton transfer reactions have been analyzed in the present work. These kind of transfer reactions is an excellent tool to get insights into the short-range correlations on nucleons in a nuclear state. The direct and sequential two-particle transfer mechanisms, for which the valence particles can be transferred, were compared one with other to probe the populated nuclear states. Large-scale shell model calculations were performed to obtained the spectroscopic amplitudes for one and two valence particles.
Nuclear matrix elements calculation for K-forbidden β-decays
Authors: Mancino R. , De Gregorio G. , Urazbekov B.
Published: March 2023

A certain interest in the experimental nuclear physic community has been expressed for the precise detection of the β-shape of low Q-value decays, such as 9Tc →99 Ru+e
−+

v
¯

e

, tied to the search for the absolute mass of the neutrino. The necessity of a reliable way to compute the single-particle matrix elements for second forbidden operators has driven the implementation of a general algorithm to obtain the nuclear matrix elements for any given transition of generic forbiddenness K. Particular attention is then placed on the accuracy of the approximations commonly used in this context.
Research on Longitudinal Static Stability Compensation of Aircraft
Authors: Ding Lidong
Published: March 2023

An aircraft is unstable in longitudinal motion, the variation of aerodynamic derivatives and center-of-gravity position caused by altitude, speed, and fuel have a great impact on the control and stability of the aircraft. By using the Linear Matrix Inequality (LMI) approach, the longitudinal static stability of the aircraft is compensated. In addition, the pitch attitude control system is designed, and multi-objective control, including pole assignment and controlled variable constraints, is achieved during the designing process. As a result, the robustness of the system is also achieved. Finally, the simulation results of the pitch attitude control system show that this design approach is feasible.
Design of Surface FSS Laser Etching System
Authors: Zhao Dong
Published: March 2023

In order to explore how to etch high-precision FSS units on the surface of large-scale variable curvature non-expandable radome, this study designed and constructed a complete set of curved FSS laser etching systems. In the process of platform construction, by comparing the processing methods of various FSS, a galvanometer laser scanning system with high processing accuracy and efficiency was selected and equipped with a servo motion system. The proposed system can realize high-precision laser etching processing of frequency selection surface and thus provide a reference for other similar projects and practical applications.
Numerical Simulation Study on Injection and Mixing Characteristics of Supercritical RP-3 Aviation Kerosene
Authors: Liu Penghui , Wang Zhisheng , Shi Pengyu , Fan Wei
Published: March 2023

A real gas calculation model is developed using the P-R equation of state to investigate the injection and mixing characteristics of supercritical RP-3 aviation kerosene in the combustion chamber. In this investigation, n-decane is used as an alternative fuel, and the physical parameters of n-decane at the supercritical state are calculated. The jet and mixing characteristics of supercritical kerosene in different combustion chamber models are investigated by this calculation model. The combustion chamber head configuration suitable for supercritical kerosene is obtained by analyzing the spatial inhomogeneity, the deviation of equivalent ratio fluctuation, and the mixing degree.
Preparation, Characterization, and Kinetic Analysis of Fluorine- containing Aluminum Thermite
Authors: Zhou Ying , Jiang Lin , Li Mi , Liu Jun-Wang
Published: March 2023

The addition of polytetrafluoroethylene as a binder in aluminum thermite allows the application of aluminum thermite from the traditional high temperature and high heat to the chemical corrosion direction. The stability of the samples was tested by theoretical calculations of the critical thermal explosion and mechanical sensitivity experiments. The microscopic morphology of the aluminum thermite was characterized by scanning electron microscopy, and the thermodynamic properties of the samples at different heating rates were investigated by the TG-DSC method.
Research on Active Disturbance Rejection Controller for Electromechanical Servo System with Large Inertia Loads
Authors: Zhang Zhenzhou , Qiu Qunxian , Wu Yuhang
Published: March 2023

In this paper, an Active Disturbance Rejection Controller (ADRC) based on an improved Particle Swarm Optimization (PSO) algorithm is proposed. The ADRC is conducive to addressing the situation that the electromechanical servo system is loaded with a large inertia barrel and is significantly affected by disturbances when working at high speed and precision. It can not only improve the anti-disturbance performance of the system but also ensure the dynamic performance of the system. Firstly, a simplified mathematical model of the electromechanical servo system is established and the non-linear factors of the system are analyzed. Secondly, the ADRC is designed and the parameters are optimized by utilizing the improved PSO algorithm. Finally, the control effect of the proposed method is simulated and analyzed. The simulation consequences demonstrate that compared with the traditional PID control, the proposed method can significantly increase the anti-disturbance capability of the servo system, and guarantee the accuracy index of the system.
Design of Measurement and Control System for Small Electromechanical Airplane Jack Based on Embedded Technology
Authors: Jiang Xiao-Chuan
Published: March 2023

To make the hydraulic jack meet the requirements of modern mechanical and electrical equipment, such as intelligence, high sensitivity, and good operation performance, this paper presents the design of an embedded measurement and control system for a small electric mechanical airplane jack. A new type of electric mechanical jack is designed. According to its need for strong maneuverability, a new intelligent jack measurement, and control system based on the C8051F410 single-chip microcomputer is developed. The system mainly takes the stepping motor as the power source, and the selection requirements, the parameter design of stepping motors, and their supporting drivers and controllers are mainly introduced through the control of multiple stepper motors. Two schemes are listed in the selection of controllers, and the second scheme is selected according to the actual operational needs of the system. It can control the movement of the jack, such as fast-forward, working, and walking. The test system also realizes the load stress signal of the key parts of the jack support arm, as well as the real-time acquisition and display of the height displacement signal during work. The performance of the control part of the jack control system and part of the acquisition system was verified through experiments. The experimental results prove that the system meets the design requirements of the system and the actual design requirements.
A Design of an Indoor Delivery UAV
Authors: Shi Yu-Long , Zou Shui-Zhong
Published: March 2023

With the rapid development of UAV-related directions, intelligent UAVs have been applied to various industries of modern production and life. One particularly popular application is “delivery UAV.” By giving commands to the UAV, It can accomplish complex tasks such as target point flight and cargo delivery autonomously. On the one hand, human resources can be liberated; on the other hand, fully automated operations can greatly improve production efficiency. Our team used STM32 produced by Stmicroelectronics as the main control of the UAV, OpenMV from SingTown Technology, and K210 from Canaan Technology as the vision processor to design and develop a delivery quadrotor. The UAV uses an optical flow module to achieve hover and cruise and is equipped with a laser ranging module to assist the UAV in obtaining height. K210 and OpenMV are used for target detection, and the Hanging basket can be raised and lowered to simulate “delivery.” The UAV can realize automatic cruise, target-point “delivery,” target detection, obstacle avoidance, and many other functions.
Aerial-assisted task offloading approach over multilayer satellite edge computing
Authors: Wen Weichang , Cui Haixia , Shuai Jiaqi , Lu Jiangnan
Published: March 2023

Satellite communication technology can solve the signal covering issues in special areas, such as deserts and oceans, which is difficult to handle with in traditional terrestrial wireless networks. Mobile edge computing (EMC) is crucial to help satellite communication to improve latency and energy efficiency performance. In this paper, we model a satellite constellation edge computing architecture with three layers and propose a task offloading deployment approach to balance the computation task. Simulation results show that the proposed algorithm can greatly reduce the execution delay of missions, improve the utilization of satellite resources, and increase the mission success rate compared with the existing strategies.
Influence of Low Speed and High Angle of Attack on Sting Support Interference
Authors: Gao Na , WeidongYang
Published: March 2023

In order to improve the quality of low-speed and high angle of attack test data and master the law of support interference, a numerical simulation study of support interference was carried out for a wind tunnel tensioning tail brace system. The results show that the impact of the beam of wire-assistant sting support on longitudinal aerodynamics characteristics of aircraft is small, and the “E” sting greatly affects longitudinal aerodynamics characteristics at a high angle of attack. The yawing moment coefficients decrease, and rolling moment coefficients increase at the angle of attack from 0°to 20° with the existence of wire-assistant sting support. With the increase of side slip angle, the interference becomes bigger, then becomes smaller, and 30°is the biggest.
Study on Typical Flight Ground Transit Scenario
Authors: Zhou Chen
Published: March 2023

In the process of aircraft design, it is necessary to study the flight ground transit scenario. In this paper, to research a typical flight ground transit scenario, a domestic airport is selected, and the typical values of taxi distance, service transit time, and arrival flight time are assessed, analyzed, and given after the influence of passenger flow, runway, terrain, and temperature. This typical transit scenario can be used for the relevant calculations of flight transit capacity in the top-level design of the aircraft.
A Genetic algorithm-based method for tracing attack behaviors of power monitoring network
Authors: Li Huixing , Zhai Haibao , Ge Minhui , Zhang Liang , Shen Guohui , Chen Jing
Published: March 2023

Power monitoring network attack detection and defense can only target known types of attacks. This simple defense detection method cannot effectively defend against complex network attacks, so it is necessary to adopt the tracing technology of actively searching for the source of attacks. This paper discusses the electric power monitoring and control network attack, attack tracing method, and genetic algorithm. Based on applications traceability method for electric power monitoring and control network attack behavior of power monitoring data collection network and the genetic algorithm, parameter settings were described. Furthermore, the process of tracing the attack behavior of the power monitoring network based on multi-level data association and genetic algorithm is designed and discussed. The success rate of tracing the attack behavior of the power monitoring network is analyzed by four operators in the genetic algorithm. The experimental data show that the success rate of the four operators in tracing the source of the three kinds of attacks in the power monitoring network is more than 97% on average. Therefore, the method of tracing the attack behavior of the power monitoring network based on the genetic algorithm has high practical value.
The CFD Investigation of General FPSO Green Water
Authors: Li Min , Dou Peilin , Qi Yue
Published: March 2023

The main research is to investigate the seakeeping effect resulting from general FPSO hull bow flare. CFD-FV (Computational Fluid Dynamics-Finite Volume) method is applied with fluent software to simulate in the 3D time domain. Simulation objects are two different bow flare models exposed to the green water phenomenon, which is under the sea state of the Brazilian sea 20 years of return extreme sea state. Seakeeping analysis includes green water. The results indicated that a 3.5 m vertical bow flare would reduce about 35.09% level of green water on deck. A comprehensive comparison indicated that bow flare improved the global seakeeping performance, which can be used as a reference to the design of general FPSO hull bow flare.
Design and Realization of Ultra-wideband Constant Beamwidth Beamforming in a Waveguide Environment
Authors: Li Xuegang , Zhu Jie , Jiang Guoqing , Hua Runan , Yao Wuping
Published: March 2023

Array signal processing technology has been widely used in signal detection and underwater target radiation noise measurement. A design and realization method of an ultra-wideband and high-robustness constant beamwidth beamformer based on a vertical nested array is proposed. Using the nested array multiplexing, the ultra-wideband constant beamwidth beamforming was realized by using fewer array elements; the main lobe of each sub-band beam in the designed band was made to approach the desired constraint value based on the convex optimization method; the beamforming robustness and array gain were improved through the constraint of the weight vector two-norm. In the paper, the influence on beamforming due to inconsistent array element amplitude-phases in a measured waveguide environment is analyzed. The computer simulation was used to realize the measurement of constant beamwidth beamforming within a 100-octave band range in the measured waveguide environment and verify the effectiveness of the proposed method.
A Low-Frequency Unidirectional Underwater Acoustic Transducer
Authors: Wang Qiumu , Lan Yu
Published: March 2023

A unidirectional underwater acoustic transducer has the advantage of narrower beam width. In the low-frequency field, a single transducer is usually omnidirectional because its dimension is much smaller than the wavelength of the sound waves. Here, a low-frequency unidirectional underwater acoustic transducer, the Single-Sided Radiation Flextensional Transducer (SSR FT), which is driven by a stack with the longitudinal vibration, was designed by the finite-element method. The vibration mode of the transducer was first studied and analyzed. Then, an underwater harmonic response analysis of the transducer was conducted. We found that the second resonance, corresponding to the fourth vibration mode, could be unidirectional based on a specific s
br, which is the ratio of r
b (the radius of the tail mass) to l
maj (the inner length of the semi-major axis of the radiation surface). Finally, the effect of s
br on the vibration velocity and directivity of the SSR FT was investigated. We established that the vibration velocity amplitude and phase of the shell were different at the same vibration mode but at different s
br, which resulted in different directivity.
An Analytical Method of Beamwidth under Different Angles of Planar Array
Authors: Kong Qiang , Zhu Jieqi , Su Peilin
Published: March 2023

It is widely recognized that the calculation of the beam width of the large-aperture planar array through beam pattern simulation is slow and inefficient, and obtaining the ability to distinguish the target from different angles within the observation range quickly is difficult. This paper uses methods such as the array product theorem, discrete array, continuous array beam width equivalence, and coordinate transformation to acquire a more accurate analytical solution of the beam width of the planar array. The analytical value of the beam width of the planar array at different angles and the number of array elements were compared with the simulated value. The results show that with the usage of the new method, the average deviation of the beam width analytical values in different main maxima directions can reach less than 1% when the number of array elements is less than 10 elements. Compared with the simulation method, the planar array beam width can be obtained quickly and accurately by the new method.
The Correlation between the Numerical Analysis of Wake Dynamics and the General Theory of Aerodynamic Instability of a Flapping Foil
Authors: Sun Liping , Zhou Peijian , Bao Yixiang
Published: March 2023

We study the correlation between the wake dynamics analyzed by numerical simulation and the general theory of aerodynamic instability of a flapping foil. The pure pitching motion and the pure heaving motion are considered in this paper. The main parameter is the Reynolds number, here we fixed the Reynolds number at Re = 1700. We found an interesting phenomenon in our research, which is that the lift amplitude CY of the numerical simulation is consistent with the the results of the general theory of aerodynamic instability, even at low frequencies where the additional mass effect is less important. And the average thrust CT(mean) increases exponentially with the Strouhal number SRA = fA/U, which is also an interesting phenomenon. By making the lift amplitude CY dimensionless with the amplitude θ0 and h
0, we find that the dimensionless lift amplitudes CY/θ0 or CY/h
0 are distributed along the same trend under different amplitudes. Through comparison and analysis of the pure pitching motion and the pure heaving motion, We clearly found that the lift on the heaving foil is slightly lower and the change of the lift is slightly more dramatic when the frequency is small.
A Combined Passive Automatic Detection Method of Constant False Alarms and Multiple Nodes
Authors: Huang Di , Zhu Xian , Gong Yi , Chen Fuhu
Published: March 2023

Aiming at the problem of whether multi-array passive joint detection can improve the detection performance of sonar, this paper analyzes in detail the relationship between the detection probability, false alarm probability, the input signal-to-noise ratio, and integration time under the condition of single array detection, and then obtains the input signal-to-noise ratio and integration time required to achieve the same detection probability and false alarm probability under different joint detection rules. It is concluded that the multi-array joint detection can reduce the required input signal-to-noise ratio and integration time and provide detection performance, which is verified by simulation experiments.
Study on Characteristics of Particle Dynamics with Coarse Particles in Vertical and Inclined Pipeline
Authors: Ren Wanlong , Zhang Xuhui , Zhang Yan , Lu Xiaobing
Published: March 2023

The pipeline hydraulic transport is an important component of the deep-sea mineral resources. The characteristics of particle dynamics with coarse particles is investigated by using the CFD-DEM method in the vertical and inclined pipeline. The normal pipeline and abnormal pipeline mentioned in this paper refer to vertical pipeline and inclined pipeline, respectively. The particles of the normal pipeline mainly move in the middle of the pipeline, while the particles mainly concentrate on the pipeline wall in the abnormal pipeline. The velocity difference of the abnormal pipeline between liquid and particle is much greater, which can be prone to cause particle aggregation. Finally, the pipeline to be blocked can be easy to be caused by the particle aggregation in the wall of abnormal pipeline. An appropriate increase in liquid velocity can improve the phenomenon.
Experimental research on sound quality evaluation of aircraft cabin
Authors: Li Hongnian
Published: March 2023

This paper proposes a construction method for the sound quality evaluation model of the aircraft cabin. By combining the subjective with the objective method, the relationship between the subjective results and the psychoacoustic parameters is established, and the sound quality evaluation model of the sound field in the passenger cabin is formed. The model takes the characteristic acoustic parameters that are more sensitive to the human ear, such as loudness and sharpness, as input, which can efficiently obtain the subjective result of sound quality and accurately reflect the subjective quality feeling of human ear on the current sound field.
Numerical Simulation of Thermal Conductivity of Graphene Reinforced Aluminum Matrix Composites
Authors: Wang Yan , Du Xiaoming , Chi Qingbo
Published: March 2023

In order to develop materials with high thermal conductivity, aluminum matrix composites are attracting much attention. The heat transfer ability of graphene-reinforced aluminum matrix composites was numerically simulated with the finite element method. A composite model of 3D many-particle stochastic distributions is developed. The effect of temperature, volume fraction of graphene, graphene shapes and graphene orientation heat transfer capacity of composite materials was researched. Studies have shown that that the graphene volume fraction, graphene shapes and graphene orientation were significant factors for the heat transfer of the composites. As the graphene content increases, the temperature transfer capacity of the composite increases. The disc-shaped graphene with an orientation angle of 45° in composites can obtain an enhancement in the heat transfer ability of the composites.
An Investigation on the Compatibility of Epoxy Resin and Asphalt Based on Molecular Simulation
Authors: Ji Xue , Gao Lei , Zhang Ye , Gao Junqi
Published: March 2023

Epoxy resin and asphalt compatibility have a significant impact on the material qualities of epoxy-modified asphalt. At present, there is a shortage of the study on the compatibility mechanism from the standpoint of nano. This paper evaluated the influence of temperature on the compatibility of epoxy resin (ER) and asphalt using the molecular dynamics (MD) simulation approach to explore the compatibility between ER and asphalt in greater detail. First, a twelve-component molecular model of asphalt was built, as well as a model of the system following cross-linking of epoxy resin and curing agent. And model optimization and model validation were performed. Secondly, the model of ER and asphalt co-blended system was constructed by combining the optimized model with the Amorphous Cell module. Then, MD simulations were done at various temperatures to derive the solubility parameters and intermolecular interaction energy of the mixed system for each system. Finally, the compatibility of ER with asphalt at different temperatures was analyzed based on the calculation results. It was found that the compatibility of ER and asphalt was temperature dependent. As the temperature increased, the solubility parameters of ER and asphalt decreased, and the difference in solubility parameters Δδ between them took the minimum value at 170 °C. As the temperature rises, so does the total potential energy in each system, and the intermolecular interaction energy of ER and asphalt mixed system achieves the maximum value at 170 °C. Currently, the structure of ER and asphalt mixed system is the most stable, and the compatibility between the two is the best.
Design and Analysis of Extruder Head Flow Channel of Cladding Infiltration Irrigation Pipe
Authors: Shi Changyu , Lv Bing , Wang Wenshu , Ma Yuanzheng
Published: March 2023

To solve the problem of deformation and to drop off buried infiltration irrigation pipe, a kind of extruder co-extrusion die that can effectively produce clad infiltration irrigation pipe is proposed from the structure and production infiltration irrigation pipe. Through the innovative design method, the flow passage and some parts of the extruder head were designed. The model of the extruder head runner was established, and the structure of the extruder head runner was optimized by finite element analysis. Compared with the original coextrusion die, this design reduces the size of the extruder die, and can effectively enhance the plasticizing effect and uniformity, and the material flow is more stable. This method is conducive to strengthening the strength and quality of the subsurface irrigation pipe, prolonging its service life, and reducing the difficulty of maintenance and replacement of the buried subsurface irrigation pipe.
Simulation on High Strain Rate Thermal Deformation Constitutive Equation of AZ91 Magnesium Alloy
Authors: He Zhongtao , Xu Chun
Published: March 2023

The hot compression simulation experiment of AZ91 magnesium alloy was carried out by a Gleeble-1500D thermal simulation machine under the conditions of T within the range of 300~400°C,

ε
˙

within the range of 10-2~101 s−1, and a compression capacity being 70%. In order to establish the constitutive equation more accurately, this paper uses the piecewise function model to match the σ-ε curve as the necessity of making the simulated curve have a good match with the true stress-strain curve. The linear function and nonlinear function are used to match the σ-ε curve when the material reaches the stage of softening. The fitting results show that the piecewise function matches the true stress-strain curve well under different experimental circumstances of T and

ε
˙

even at a high strain rate. This indicates that the piecewise function has a better capacity in the real situation of the relationship between hot-working deformation and the stress-strain curve of magnesium alloys.
Effect of Cryogenic Cooling on Mechanical Properties and Cutting Force of 6061 Aluminum Alloy
Authors: Wang Jinhui , Duan Pengfei , Wang Tianzhong , Wang Xiangyu , Qiao Yang
Published: March 2023

With the increasingly strict environmental protection requirements, cryogenic cutting technology as an environmentally friendly machining technology has received more and more attention. In this article, the affect of cryogenic cooling on the mechanical behaviors, cutting force and swarf shape of 6061 Aluminum Alloy were studied. Test result display that cryogenic increase strength of materials and reduces the plasticity of the material. Cryogenic cooling improves the cutting force and improves the chip breaking effect.
Study on matching layer of ultrasonic transducer for defect detection of stainless steel
Authors: Liu Luyu , Hou Huaishu , Wang Zongren
Published: March 2023

To solve the impedance mismatch problem between the piezoelectric wafer and the tested material when ultrasonic testing is used to detect the internal defects of materials, alumina powder and epoxy resin are compounded to prepare the matching layer material. Then the matching layer of the ultrasonic transducer is designed according to the quarter wavelength theory. The pulse-echo signal of the developed matching layer is tested and analyzed. The results show that the sound velocity of the matching layer is consistent with the changing trend of the acoustic impedance. That is, the acoustic impedance increases with the increase of the alumina mass fraction, and the density is 1080.73kg/m³. The ultrasonic transducer was designed by matching layer with a sound velocity of 1059.49m/s, with an acoustic impedance of 1.14mryal and acoustic attenuation coefficient of 0.1279dB/mm has good bandwidth and sensitivity.
The Effect of Heating and Cooling Process During Quenching treatment on Microstructures and Properties of Wear-Resistant Steel NM450
Authors: Ji WenBo , Lin TianZi , Zuo YuJian , Zhang Tao , Tian HongXin , Wang Yong , Wang YingShuo
Published: March 2023

Quenching is a conventional production process of wear-resistant steel, which has a decisive effect on the properties of wear-resistant steel. In this paper, the effects of quenching treatment on microstructures and mechanical properties of NM450 wear-resistant steel were investigated by optical microscopy and scanning electric microscopy. The results show that during the process of heating temperature of 880 °C and air cooling to 850 °C before quenching, the ductility and toughness of NM450 were improved significantly, whose comprehensive properties are better than 880 °C or 850 °C direct quenching steel. With the proportion of ferrite increasing, the strength of NM450 decreases, but the toughness doesn`t increase as influenced by grain size and grain boundary segregation. The martensite of intercritical quenching NM450 appears a shape massive, not lath.
Study on Cold Hardening and Recrystallization Temperature of Cu-Ni-Sn-P Alloy for Integrated Circuit Lead Frame
Authors: Yuan Hefeng , Yang Qi , Chen Jiacheng , Tao Jie
Published: March 2023

The work hardening curve of the Cu-Ni-Sn-P alloy for the integrated circuit lead frame was drawn by different degrees of cold deformation. The recrystallization temperature of the alloy was determined by testing the tensile strength, Vickers hardness, elongation, and electrical conductivity of the samples annealed at different temperatures and microstructure observation. The results show that the Cu-Ni-Sn-P alloy had obvious work hardening characteristics after being deformed by cold rolling; the tensile strength of the alloy showed a trend of first increasing and then tending to be stable with the increase of the working rate, while the elongation and electrical conductivity showed the opposite changing law. At the same annealing time, with the increase of annealing temperature, the tensile strength of Cu-Ni-Sn-P alloy decreased slowly first and then sharply, and finally tended to be stable. To effectively reduce energy consumption and shorten the production cycle, the reasonable recrystallization annealing system of Cu-Ni-Sn-P alloy after 60% deformation is determined to be 440°C×4h.
Design of calculation model of residual stress in austenitic stainless steel during plastic deformation
Authors: Deng Xiaoting , Zhang Shihong , Cheng Ming
Published: March 2023

In the process of processing, the residual stress in the deformed component will play a crucial role in the assembly and future use. This paper analyzes the deformation behavior of martensite phase transition induced by deformation through unidirectional stretching. The martensite phase variables and residual stress distributions after stretching were measured. The calculation model of residual stress distribution is established considering the phase change factors. It provides a theoretical basis for the calculation of phase transition behavior and residual stress distribution in the complex deformation process. A dynamic model based on stress and strain was established under different conditions, and the realization of martensite transformation was added to the finite element software with the help of secondary development subroutine. By comparing with the test data, the results show that the distribution pattern of residual stress can better reflect the residual stress after deformation under the consideration of the phase transformation of martensite.
Effects of surface roughness on fatigue behavior of additively manufactured stainless steel 316L
Authors: Zeng Guowei , Ye Wanrong , Liu Lei
Published: March 2023

Surface roughness plays an important role which affects the fatigue performance of additively manufactured metal components. Surface roughness generally contains micro-notches which form stress concentration and significantly deteriorate the fatigue life. Based on nonlinear elastoplasticity finite element (FE) analyses, the roughness model of additively manufactured stainless steel 316L (SS316L) was performed, and the cyclic behavior of surface notch root material under different fatigue stress loads was captured. The stress concentration factor on the selected critical surface position is calculated and the notch root strain analysis are proved by depending on the applied load level. Finally two distinct deformation modes are found: elastic shakedown and ratcheting deformation.
Study on the high-temperature corrosion behavior of 316Ti austenitic stainless steel for lead-bismuth cooled fast reactor application
Authors: Yuan Ganfeng , Sun Yulin , Wang Da , Ma Xianfeng , Zeng Jun , Liang Yuqiang , Ye Huanmin , Liu Sirui , Xiao Changquan , Hu Yanying
Published: March 2023

The austenitic stainless steel 316Ti with the addition of titanium is a promising candidate for fuel cladding due to its excellent corrosion resistance performance in LBE. In this paper, the corrosion behaviour of 316Ti steel in the static Lead-Bismuth Eutectic (LBE) for 1000 h at 550 °C is studied. The surface and cross-section morphologies of samples after corrosion were examined using Scanning Electron Microscope, Energy-Dispersive X-ray Spectroscopy and X-ray Diffraction. It concluded that the 316Ti undergoes both oxidations accompanied by the formation of a double-layer oxides and elements leaching that resulted in the nonuniform distribution of Cr, Ni, and Fe near the matrix/LBE interfac. The external oxide film mostly consisted by Fe3O4, and the internal oxide layer is primarily Fe-Cr spinel.
Design of Control System for Cultural Relics Testing Room Based on STM32
Authors: Huang Yangyang , Cui Ming , Li Bangyu
Published: March 2023

This paper designs a control system for a cultural relic test chamber based on STM32. The system uses the STM32 processor as the underlying main control of oxygen concentration and humidity and uses an industrial all-in-one machine as the bridge to exchange the information between the cloud server and the bottom master controller. The oxygen concentration, humidity and temperature data of the test chamber can be stored on the server in real-time, and the alarm messages are sent through the cloud SMS platform. The results reveal that the oxygen concentration in the test chamber could be adjusted continuously between 0.6% ~ 10% VOL and the relative humidity could be adjusted continuously within 45% ~ 55% RH, and it can keep stable near the set value. The system can meet the requirements of oxygen concentration and humidity for most cultural relics preservation and can also provide a settable constant oxygen concentration and humidity environment for the related research of anoxic treatment and modified atmosphere technology.
Analysis of Pressure Impact Characteristics of a Hydraulic Position Servo System Based on Series Servo Valves
Authors: Mao Xuyao , Xiang Chao , Hu Juhua , Wu Zhengjiang , Zeng Baoping
Published: March 2023

As one of the causes of system vibration and noise, pressure impact is always undesired. Analysis of pressure impact characteristics of a hydraulic position servo system based on a two-stage series servo valve is carried out to reduce the system impact. The influence of factors such as system flow rate, additional servo valve opening gain, external load, and system overflow pressure on the system pressure impact is analyzed. The results show that the series servo valve scheme can bring down the peak impact pressure at the inlet of the hydraulic cylinder by 8%~11% when the system flow rate or overflow pressure is low to a certain extent. In most other cases, the suppression effect of the impact peak pressure is unapparent. The impact pressure overshoot is always decreased accompanied by an easier trend to overflow for the system. At last, another new idea of application promotion with higher reliability and adaptability is proposed.
Study on the Influence of Vacuum Vapor Phase Soldering Process Technology on SiP Component
Authors: Li Saipeng , Jiang Qinglei , Wang Xuyan , Li Jiutian
Published: March 2023

Vapor phase soldering (VPS) is used in the assembly of highly reliable electronic products for aerospace, military, and industrial area for the advantages of heat transfer coefficient, good temperature uniformity, and controllable maximum soldering temperature. VPS is usually used for PCB (Printed Circuit Board) and complex components. However, little research has been done on the application of VPS process technology on the SiP (System in Package) component in the process of solder ball or solder column package. In this work, we investigated the influence of the vacuum VPS process on the SiP component. The advantages of VPS and vacuum process were discussed and the maximum shear strength of solder joints in the vacuum process was calculated. The vacuum process has no impact on the internal structure of the SiP component.
Inverse attitude solution of manipulator based on improved quaternion
Authors: Yin Gui , Ju Hehua , Chen Feifei
Published: March 2023

Typically, quaternions or rotational matrices are used to establish kinematic equations and produce inverse kinematic solutions for the attitude of 6R decoupled manipulators. These approaches have certain drawbacks, such as duplicate equations and manual solution processes that cannot be eliminated automatically. In this study, we introduce the Ju-Gibbs quaternion to establish the kinematic equations, which are isomorphic to the Euler quaternion and share the same mathematical characteristics. Using this modeling method, one can create non-redundant kinematic equations wherein the number of equations equals the number of unknowns. A novel Dixon elimination method is then used to resolve the multilinear problem. Since no division operations are involved in the solution process, the solution has the advantage of being free of computation singularity issues. The experiment verifies that the proposed method can accomplish the autonomous modeling and elimination solution process of 6R manipulators with low computation complexity and high precision.