bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue Life Calculation of Shaft System Based on Bend-Torsion Coupling
Authors: Gang Liu , Yong Shao 
Published: August 2019

Abstract
The increase of the propulsion power of the ship and the increase of the distance between the two adjacent bearings lead to the reduction of the fatigue life of the shaft system. The research on the fatigue life of the ship propulsion shaft system has important theoretical significance and practical engineering application value for the ship design. Based on the ANSYS Workbench platform, this paper builds the physical model of the coupling part of the bending and torsion, obtains the transient analysis result under the working speed, and introduces it into ANSYS Ncode for fatigue analysis under flexural and torsional coupling.
Effects of interfaces heat fluxes on the rheological and flow behaviours of melt in the gas-assisted extrusion of plastic micro-tube
Authors: Ren Zhong , Huang Xingyuan 
Published: August 2019

Abstract
In this study, the effects of interfaces heat fluxes on the rheological and flow behaviors of melt in the gas-assisted extrusion of plastic micro-tube were numerically investigated. In the numerical studies, the heat transfer effect at the interfaces between the annual melt and two layers of assisted gases were considered. Under four different heat transfer coefficients, the radial and axial velocities, pressure, temperature, and viscosity distributions along the axial direction of die were obtained. Numerical results show that, in the gas-assisted extrusion of plastic micro-tube, with the increase of interfaces heat fluxes (heat transfer coefficient), the radial velocity, axial velocity, and temperature distributions of melt gradually increases, but the pressure, viscosity of melt gradually decreases. At the same time, the larger interfaces heat fluxes will result in the better flowability of melt in the gas-assisted extrusion of plastic micro-tube.
Effects of Sm on Microstructure of Mg-12Gd-2Y-0.5Zr Alloy
Authors: Li Kejie , Xu Haojie , Tong Zhangming 
Published: August 2019

Abstract
By alloy melting, microstructure analysis and micro-hardness test, the effects of Sm addition on the microstructure of Mg-12Gd-2Y-0.5Zr alloy with solution treatment and aging treatment were investigated. The results showed that the microstructure of the tested alloy consisted of α-Mg matrix, Mg41Sm5, Mg5Gdm, Mg24Y5 and β’ phases, and Sm improved the micro-hardness value of α-Mg matrix attributed to its better solid solution strengthening effect in α-Mg. The micro-hardness of the alloy with Sm increases obviously from HV121.4 to HV134.3 when compared with that of Mg-12Gd-2Y-0.5Zr alloy.
Epitaxial ZnO on p-Si and its MSM Structure Photoconductive Ultraviolet Detector
Authors: Zhong Wen’an , Liu Jianfeng , Zhao Yu , Zhang Quanlin , Zhao Yijun , Wang Yuchao 
Published: August 2019

Abstract
In this work, a plasma-assisted molecular-beam epitaxy (PA-MBE) was used to prepare high-quality ZnO thin films on p-type silicon substrates. Be/BeO composite buffer layers were designed to improve the crystal quality of ZnO thin films. Based on the ZnO thin films, we fabricated interdigitated electrode MSM structure photoconductive UV detector by lithography, electron beam evaporation and other traditional semiconductor processes. In addition, dark current, spectral response of the UV detector were measured by responsivity testing system to explore the application of ZnO based UV detectors.
Study on Fretting Wear Properties of High Speed Diesel Engine Roller Tappet Material Cr12W Steel
Authors: Guo Xiaolong , Cai Yuqing , Lai Fuqiang , Wang Jialin , Li Zhengxian , Qu Shengguan 
Published: August 2019

Abstract
The cam and tappet are key components of the internal combustion engine valve train system. Due to the alternating high-frequency cyclic of high contact stress, the cam and tappet are prone to abnormal wear and failure. In this work, Cr12W steel was selected as the material of the roller tappet in valve train. Then, it was treated by ion nitriding treatment. The fretting wear tests were carried out under laboratory conditions. The wear mechanisms of nitrided and untreated specimens which rubbed with GCr15 steel were investigated under dry friction and oil lubrication, respectively. It is found out that the predominant wear mechanisms of nitrided specimens under dry friction are slight abrasive wear and adhesive wear, whereas under oil lubrication, it is mainly spalling. The wear mechanisms of untreated specimens under dry friction are identified as adhesive wear and oxidative wear, while it is mainly abrasive wear under oil lubrication.
Research of intergranular corrosion properties of heat affected zone for HR3C steel after aging treatment
Authors: Xinmei Li , Zhongwen Zhang , Nan Li , Baoshuai Du , Xiulian Li , Yuzhong Wei 
Published: August 2019

Abstract
The intergranular corrosion susceptibility of heat affeceed zone(HAZ) for HR3C steel after aging at 600°C was investigated using electrochemical double-loop potentiokinetic reactivation. Experimental results show that HAZ has intergranular corrosion susceptibility after aging at 600°C. At the initial stage precipition of M23C6 along grain boundaries occurs rapidly, which leads to formation of Cr-depleted in the grain boundary and the increase of intergranular corrosion susceptibility. With the increase of aging time, the Ra value of HAZ rapidly increase. Intergranular corrosion of HAZ after aging occur due to the precipitation of M23C6 along grain boundaries, not only the precipitation of M23C6 along grain boundaries caused poor Cr, but the precipitation of M23C6 inside the grains also results in the formation of Cr-depleted zone and subsequent corrosion.
Ablation morphology and redistribution layer of gold films with different substrates irradiated by femtosecond laser pulse
Authors: Xu Zhijie 
Published: August 2019

Abstract
Gold micro/nanostructure is of great significance in many scientific and engineering fields for its unique optical, electrical and thermal properties. Gold film deposited through electron beam (EB) evaporation is a suitable raw material for the fabrication of gold micro/nanostructure. Femtosecond laser directing is one of the reported methods for high-efficiency and low-cost micro/nanofabrication. We present a comparative study of gold film ablation with different substrates (Si, SiO2, ZnO) under the irradiation of single femtosecond Gaussian pulse. The morphologies of ablation areas and redistribution layers are investigated by many characterization methods, such as scanning electron microscopy (SEM) and atomic force microscopy (AFM). In general, the ablation morphology and the ablation hole are mainly affected by the bandgap. Besides, the heat conductivity is the main factor affecting the width and height of the redistribution layer.
Study on Friction Properties of WC Particle-Reinforced High-Chromium Iron-Based Powder Metallurgy Materials
Authors: Wei Tao , Ma Mengyang , Li Ziyang , Qin Shunshun , Wang Chengzong , Li Xiaoqiang 
Published: August 2019

Abstract
High-performance powder metallurgy high-chromium iron-based alloy reinforced by nano-WC particles were prepared by high-energy ball milling combined with hot-press sintering. The effects of different temperatures of hot-press sintering and contents of WC reinforced phase on the friction and wear properties of the materials were studied by using the M-2000 Friction and Wear Tester under dry condition. The results show that the wear property of the material increases first, and then decreases with the growth of temperature of sintering and contents of reinforced phase. The alloy has the best wear property sintered at 1050 °C with 5wt.% WC reinforced phase. By comparing with NbC reinforced phase with similar mass fraction at 5%, finding that WC particles have more significant effect on reinforcing the wear
Research on Dielectric Loss Angle of Capacitive Equipment Based on Blackman Window Improved FFT
Authors: Cai Hanxian , Zheng Fangqing , Lu Xuerong 
Published: August 2019

Abstract
According to the fact that the dielectric loss angle of capacitive equipment is mainly determined by the phase difference between its terminal voltage and leakage current, cutting short the voltage and current signals by Blackman window, and correcting the spectrum of voltage and current signals by three-spectral line interpolation method and 7-order polynomial fitting technique, a simple and practical frequency correction formula and a formula for calculating dielectric loss angle based on improved FFT are given. The results of simulation and measurement show that the spectrum correction method presented in this paper is effective under harmonic interference and frequency fluctuation of power grid, and the measurement results of dielectric loss angle delta are accurate and stable.
Study on the stirred blade mounting height-to-liquid level-ratio related to the law of flow field inside the stirred reactor
Authors: Cheng Lei , Zhang Zhenwei , Zhao Xinyu , Lin Qia 
Published: August 2019

Abstract
To figure out the law of the height of stirred blade installed inside the reactor affect the fluid inside, this article used CFD to Numerical simulation of the liquid filled area of the stirred reactor, then obtain the distribution of the liquid velocity field inside the reactor.Through the comparison of calculation. Consider the weak area of stirred mainly concentrated above the stirred blade, when stirred blade were installed at the stirred blade mounting height-to-liquid level-ratio reach to 40%, ti means the mixing level reach maximum, according to the calculation the average turbulence kinetic energy is 0.003407-40 0.002994-45. and standard deviation of turbulence kinetic energy is able to stable between 0.001503-40 to 0.001275-45.
Fuel Consumption Model of Aircraft in Descent Stage Based on DBN
Authors: Wu Zhentao , Li Xueren , Du Jun 
Published: August 2019

Abstract
Due to the pressures of the current ecological environment and the rise of fuel prices, it is necessary to calculate the fuel volume of aircraft accurately. In order to calculate the fuel consumption of a flight, the key is to establish an accurate fuel consumption model. In the process of descent, because the environment around the aircraft changes dramatically, compared with other stages, the fuel consumption factors affecting the descent stage will be more. But at present, the domestic fuel consumption model for aircraft descent stage is not accurate enough. To solve this problem, a method of building fuel consumption model in aircraft descent stage based on flight data using Deep Belief Network (DBN) is proposed. Firstly, the parameters related to fuel consumption are selected from the flight data, then the correlation between each parameter and fuel consumption rate is calculated by mutual information algorithm, and finally the parameters with the highest correlation are selected for model training. Compared with the traditional BP neural network and Echo State Network (ESN), the accuracy has been greatly improved.
Research and Design of proximity fuze Scheme Based on 24GHz Radar Sensor
Authors: Tian Zheng-gang , Liu Cheng-an 
Published: August 2019

Abstract
Modern warfare requires more and more adaptability to the environment. The proximity fuze based on microwave radar sensor has high anti-interference performance, which can achieve accurate hit and high efficiency damage in the complex environment. The microwave radar sensor has the characteristics of strong anti-interference ability, high precision of ranging and high speed measurement, and can accurately extract target information. This paper mainly introduces a design and implementation scheme of proximity fuze based on 24GHz microwave radar. With a small spatial structure and high integration, combined with the Doppler principle, antenna scanning technology and FFT system software design, the detonation range of the lowest 0.5m and 30m is determined effectively and reliably with a low false alarm probability.
Design of a High Resolution TDC Based on Multi-channel
Authors: Zhang Qingsong , Xu Guanghui , Li Na 
Published: August 2019

Abstract
In this paper, a high precision time digital converter (TDC) system is designed based on Xilinx 7 series FPGA chip, which includes fine time measurement module, logic control module, rough count module and display module. The key point of FPGA TDC design is that there are a large number of delay units in the underlying hardware resources with stable delay. A delay chain consisting of 64 fast carry chains (CARRY4) is constructed by using the CARRY4 module inherent in the chip. In addition, the code density method is used to solve the nonlinear problem of internal special carry chain delay unit, effectively eliminate the error caused by wiring path, and reduce the integral nonlinear and differential nonlinear error. The experimental results show that the code density method can accurately reflect the distribution of delay time.
A DTN Routing Scheme for LEO Satellites Topology
Authors: Qi YaoWen , Yang Li , Chen ShuangJian 
Published: August 2019

Abstract
In delay/disruption-tolerant satellite networks, the existing routing algorithms have problems of long transmission delay, high packet loss rate, excessive network overhead and other issues. In the view of these shortcomings, an improved contact graph routing algorithm, ICGR, is proposed in this paper. Firstly, the impact of queuing delay is considered by defining a queue factor and proposing a queue scheduling mechanism in routing calculation; secondly, the effects of contact’s remaining capacity are taken into account to avoid the selected path being unable to forward the messages; thirdly, routing update mechanism is optimized by designing a message path update factor to strike a balance between real-time updates of transmission and resource consumption; finally, a LEO satellite network simulation platform is built with OPNET to verify the performance of this algorithm. Simulation results show that the ICGR, compared with the ED and CGR algorithm, has advantage in packet delivery rate, average transmission delay and network overhead.
Research on the Key Technology of Safety Protection in Application Environment of Blockchain
Authors: Zhang Hua , Wang Jiong , Xu Ge , Ruan Zhiqiang 
Published: August 2019

Abstract
This paper analyzes the current situation of blockchain application security. Then, makes a concrete analysis on the problems existing in the application safety of blockchain, including the attack of consensus algorithm, the leakage of privacy, and the programming vulnerability of blockchain and hash collisions. Then it introduces in detail the three key technologies of security protection under the blockchain application environment, P2P network technology, asymmetric encryption technology and consensus mechanism technology. In order to make more relevant people know more about the key technologies of safety protection in the application environment of blockchain.
A Method of Stable Extended Kalman filter
Authors: Peng Gu , Kai Wang , Shicang Zhang 
Published: August 2019

Abstract
The extend kalman filter provides an stability solution to the approximate nonlinear-Gaussian filter problem. Due to the limitation of the word length of the processor, the rounding errors is easy to occur in the calculation, which causes the covariance matrix to lose its positive definite and convergence. In order to solve this problem, The proposed stable extended kalman filter (SEKF) method is applied to the problem of non-positive and divergence in recursive filter. This method introduces the matrix decomposition and constructs a covariance square root adaptive filter which is used to solve the numerical stability problem of the extend kalman filter. Experimental results show that SEKF can effectively guarantee symmetric positive definite in recursive calculation, and perform remarkably better than EKF algorithm.
MI-based optimal jamming waveform design
Authors: Chen Xu , Wang Bin , Yu Hao , Xin Fengming , Wang Jinkuan 
Published: August 2019

Abstract
In order to improve the estimation performance of radar system, previous studies on radar waveform design mostly focused on maximizing the mutual information between the target and the echo to design the transmitted waveform. However, these studies neglect the existence of jammer in the actual electromagnetic environment, so this paper introduces a jammer to design the corresponding jamming waveforms according to whether there are signal-related clutter or not, which weakens the estimation performance of radar system. Simulation results show that the energy allocation strategies of the two jamming waveforms are different.
Design of Ultrasonic Guided Waves Signal Generator Based on FPGA
Authors: Yang Jie , Qu Zhigang 
Published: August 2019

Abstract
Ultrasonic guided waves have been widely concerned in recent years due to their long transmission distance, wide coverage, and no influence on production. In the future, they have great potential to become a new descaling method widely used in industry. Piezoelectric ultrasonic transducer is an actuator based on ultrasonic guided waves descaling system, which requires high-precision signal source to drive. This paper designs a high-precision signal generator based on FPGA. The DDS signal generator based on FPGA and the ultrasonic guided waves descaling system based on FPGA are introduced. Through theoretical analysis and experimental verification, the test results show that the FPGA-based signal generator can generate the required excitation signal, and the FPGA-based ultrasonic guided waves descaling system proposes a new descaling method for the industry.
The design of Handheld Stabilizer with Follow Focus Function
Authors: Liao Yinhan , Song Shuxiang , Li Rui , Lu Lifen , Xia Haiying 
Published: August 2019

Abstract
In this paper, we design a follow focus system, which can be integrated with a handheld stabilizer. The follow focus system of the handheld stabilizer includes the following steps: establishing communication relationship, signal input, signal transmission, focusing control and adjusting camera parameters. The follow focus system solves the problem that the parameters of the follow focus and the platform need to be adjusted by both hands. It optimizes the problem of wire winding in stabilizer, while it combined with the follow focus wired control. It indirectly shortens the response delay of the wireless follow focus by using the internal wiring of the stabilizer. It achieves not only adjusting the camera parameters, but also stabilizing the follow focus of the real-time camera.
Design of sparse cosine modulated filter banks based on Hopfield neural network
Authors: Xu Wei , Gao Xin , Zhao Jiaxiang 
Published: August 2019

Abstract
Cosine modulated filter bank (CMFB) is the most basic and important module in multi-rate signal processing system. Sparse FIR linear-phase CMFB can not only reduce the complexity of hardware design, but also ensure good performance. In this paper, a new design method of CMFB is proposed. First, the set of sparse coefficients of the prototype filter is found by using the orthogonal matching pursuit (OMP) algorithm. Then the Hopfield neural network (HNN) is employed to optimize the non-zero coefficients. The analytical and simulation results demonstrate that the new approach not only ensures that the sparse CMFBs satisfy near perfect reconstruction (NPR), but also improves the efficiency of hardware operation.
I3D-LSTM: A New Model for Human Action Recognition
Authors: Wang Xianyuan , Miao Zhenjiang , Zhang Ruyi , Hao Shanshan 
Published: August 2019

Abstract
Action recognition has already been a heated research topic recently, which attempts to classify different human actions in videos. The current main-stream methods generally utilize ImageNet-pretrained model as features extractor, however it’s not the optimal choice to pretrain a model for classifying videos on a huge still image dataset. What’s more, very few works notice that 3D convolution neural network(3D CNN) is better for low-level spatial-temporal features extraction while recurrent neural network(RNN) is better for modelling high-level temporal feature sequences. Consequently, a novel model is proposed in our work to address the two problems mentioned above. First, we pretrain 3D CNN model on huge video action recognition dataset Kinetics to improve generality of the model. And then long short term memory(LSTM) is introduced to model the high-level temporal features produced by the Kinetics-pretrained 3D CNN model. Our experiments results show that the Kinetics-pretrained model can generally outperform ImageNet-pretrained model. And our proposed network finally achieve leading performance on UCF-101 dataset.
A Sea Wave Surge Base Alignment Test Device Based on the EtherCAT Fieldbus
Authors: An Kangkang , Huang JinXin , Li ChongLing 
Published: August 2019

Abstract
A sea wave surge base alignment test device consisting of a linear motion guide rail, a stewart platform, a rotating mechanism, a cantilever beam and an electronic control system based on an EtherCAT fieldbus is designed. The linear motion guide and the stewart platform provide the seven movement dimensions for the whole device. the rotating mechanism, the cantilever beam and the linear motion guide widen the movement dimension and amplitude of the device.the EherCAT fieldbus effectively satisfies the real-time, synchronization and accuracy of the whole device. the whole system effectively satisfies the requirements of multi-degree, large amplitude, low frequency, large acceleration combined superimposed rocking motion and simulation motion in the sea wave surge simulation motion.
Realizing High-order Bessel Vortex Beams with High-level Phase Holograms
Authors: Zhai Zhongsheng , Huang Jiaojie , Cheng Zhuang , Lv Qinghua , Wang Xuanze 
Published: August 2019

Abstract
High-order Bessel beams are widely used in laser processing and precision measurement. For the realization of high-order Bessel beams, a spatial light modulator is used to load the high-order phase hologram instead of the real spiral phase plate and the axicon. The distribution of light field in two modes of axicon combination and phase superposition is analyzed theoretically. The beam modulation in two modes is designed and compared experimentally. The results show that the modulation effect of the phase superposition method is better than that of the axicon combination method. Meanwhile, the operation is flexible and the manufacture errors can be reduced. It is an effective method for realizing high-order Bessel beams.
A General Parameterized High Precision Finite Element Modelling Method of Three-dimensional Helical Gear
Authors: Liu Yanping , Zhao Yongqiang , Liu Ming , Sun Xiaoyu 
Published: August 2019

Abstract
In order to be able to perform an LTCA with satisfactory accuracy and time consuming, a parameterized approach to establishing a high-precision three-dimension (3D) finite element model (FEM) of involute spur/helical gears is proposed. The enveloping theory and dentiform normal method are applied to deduce the mathematical representations of the root transit curve as well as the involute tooth profile of the external gear in the transverse plane based on the manufacturing process and an accurate description of the cutter. The bottom-up modelling method is used to build the finite element model of the helical gear directly without create the geometry model in advance. A computer program is developed to establish 3D helical gear finite element model of any parameters and mesh density automatically. Computerized tooth contact analysis of load sharing and con-tact pressure as well as transmission error and mesh stiffness are also simulated and calculated. This methodology can also use to create other types of involute gears, such as involute helical gears with crossed axes or spiral bevel gears.