bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Nonlinear Opto-Mechanical System for Improving Detection Performance
Authors: Xing Weichen , Kong Dezhi , Wang Xin
Published: April 2021

In this paper, the use of optical parametric amplifier to effectively improve the detection performance of nonlinear opto-mechanical system is studied theoretically. At the same time, it is found that by adjusting the nonlinear gain of the optical parametric amplifier and the effective detuning between the input light field and the cavity field, the quantum noise of about 14dB in the squeezed quadrature can be reduced, and the sensitivity of weak force detection can be increased by more than 2 times. On the other hand, the phenomenon of reaction noise cancellation caused by nonlinear cavity combined with homodyne measurement is analyzed and the method of quantum non-destructive measurement is realized, which provides technical reference for weak force detection of nonlinear opto-mechanical system.
Current Status and Development Trend Analysis of Neutron Logging in Uranium Mines in China
Authors: Liu Zhifeng , Ding Chenglong , Wang Ruyang , Cao Junwu
Published: April 2021

Neutron logging is a method of measuring uranium fission neutrons by bombarding uranium in ore beds with neutrons emitted by neutron sources or neutron generators. The pulsed neutron logging technology of uranium ore has been popularized and applied in the United States, Russia, Australia and other countries. The key technology is almost monopolized by these countries, but the technology is prohibited in China. In the field of uranium logging, natural gamma logging has always been used in China for uranium quantification, which is characterized by large error, low efficiency, high cost and technical and economic bottlenecks. Due to the fact that the research and application of pulsed neutron log in the field of petroleum exploration and production is relatively mature in China, it is urgent to develop relevant logging instruments and uranium quantitative interpretation methods as independent intellectual property rights. This will lead to a change in the backward appearance of uranium logging. This paper analyzes the research status and development trend of neutron logging in uranium at home and abroad.
Several Ways to Implement Qubits in Physics
Authors: Lu Fan
Published: April 2021

In order to achieve quantum computation, the qubit preparation is crucial, given that the performance relies on various gate operations, which is determined by the quality of qubit. This paper introduces many qubits, including atoms (neutral atoms and ions) and spins (quantum dots, diamond NV centers, and nuclear magnetic resonance) that depend on various systems. Moreover, they are mentioned separately in this paper due to the significance of superconducting qubits. Meanwhile, the advantages and drawbacks of these qubits are compared, e.g. their coherence (long coherence time between neutral atoms and ions), operating temperature, quantum state reading, quantum system ease of handling, and precision of handling. Challenges as well as corresponding resolved methods have been addressed and reviewed. Current gaps and limitations are also discussed.
Design and Application of Optical System Based on Terahertz Time-of-Flight Imaging
Authors: Wang Yujian , Liu Yongli , Wang Bo , Zhu Xinyong
Published: April 2021

Using the penetration and transientness of Terahertz pulses and the photoconductive delayed detection method, the tomographic imaging of the interior of the object based on the time of flight can be realized. By comparing the transmittance of several crystals and polymers in the Terahertz band, Polymethylpentene (TPX) was selected as the material of Terahertz lens, and High Resistivity Float Zone Silicon (HRFZ-Si) as the material of beam splitter; By comparing the focal depth of normal incidence and oblique incidence optics system, the normal incidence optical system was used to realize time-of-flight imaging; Using the idea of optical-mechanical integration, the corresponding optical camera is designed according to the normal incidence optical system, and the peak-to-valley map and thickness map of the Lithium cobaltate coating of aluminum foil were obtained by time-of-flight imaging, and the defects such as complete shedding of the coating and uneven thickness were observed. The results show that the normal incidence optical system can realize Terahertz time-of-flight imaging and is applicable in the industrial nondestructive testing field.
Visualization Analysis of Nano-Flame Retardant Materials Based on Citespace
Authors: Zhang Dingran , Kong Lingqian , Li Yuanhan , Wang Huiya
Published: April 2021

Based on 3083 articles in the research field of nano-flame retardant materials collected from The Web of Science database from January 1, 2000, to December 31, 2019, the author, institution analysis, keyword analysis and journal co-citation analysis were carried out with Citespace software and bibliometrics method, and the relevant visual knowledge atlas was drawn. The results show that the development of nano-flame retardant materials can be roughly divided into three stages: exploration stage (2000-2005), steady development stage (2006-2013), and rapid growth stage (2014-2019). Yuan Hu, a professor at the State Key Laboratory of Fire Science at the University of Science and Technology of China, and his team published the most articles. The Nanocomposite is the most representative research topic. Keywords zirconium phosphate has the highest frequency of occurrence. The periodical DEGRADATION AND STABILITY has been cited the most. Above all, nano flame retardant materials is a young but the heat of the research subject, this paper reveals the authors and institutions of cooperation relations, the Subject of co-occurrence relations, the relationship between journals were cited in the field of knowledge base, hotspot and development trend of the series of research, in order to provide a valuable reference for the development of its.
Investigation and Optimization Research on Online and Offline Blended Learning of Higher Vocational English from the Perspective of CoI Algorithm
Authors: Jin Xu
Published: April 2021

With the development of information technology, online and offline blended learning has become a universal learning form. In order to investigate and optimize the online and offline blended learning of English in higher vocational colleges, this paper introduces the CoI theory to analyze blended learning. First, design the questionnaire based on the three elements of the CoI theory. After analyzing the results of the questionnaire, conduct related experiments. In order to ensure the accuracy of the results, an experimental group and a control group are set up. After three months, most of the students in the experimental group have improved their performance. The experimental results show that blended learning has a certain positive effect on the improvement of vocational students’ English performance. In addition, it is found through research that there are certain differences in the promoting effect of blended learning on English scores under different scores. Therefore, this article puts forward some suggestions for blended learning.
Color Characteristics of Four-Color Samples in the Foggy Environment under Different Lighting Conditions
Authors: Cui Ganggang , Zhou Xiaoli , Qian Yong , Zhang Zheqian , Liu Muqing
Published: April 2021

Traffic signs should provide clear signals for drivers and passengers under various environmental and geographic conditions. In foggy weather, the signal will be disturbed due to light scattering, which will cause obstacles to recognition. This study simulated a foggy environment in the laboratory, used a standard color card as the target, and introduced a colorimeter to record the color coordinates, then calculated the color difference and analyzed the four-color samples’ color properties in different lighting conditions. We found that as the relative visibility increases, the chromatic aberration of the sample will gradually decrease under different lighting conditions and reach zero when the relative visibility is higher than 70%. We found that the green and blue samples have better color coordinate retention capabilities than the fog’s red and yellow. We compared all tested light sources’ performance, and the results showed that 3000K LED and incandescent lamps are better than other light sources. This study will provide a data basis for the study of traffic safety and accident prevention.
An Integrated Silicon Photonic Chip for Continuous-Variable Quantum Random Numbers Generator Based on Vacuum Fluctuation
Authors: Zhu Menglin , Wang Xiangyu , Xu Bingjie , Yu Song , Chen Ziyang , Guo Hong
Published: April 2021

The deployment of quantum random number generator in fiber optics is strongly limited in real world applications due to the size of the components and their cost. Here we present a quantum random number generator based on vacuum fluctuation using an optical homodyne detection in silicon photonic chip achieving minimum entropy/bit of 8.5 for 10 bits sample. The produced random numbers have passed all NIST randomness tests.
Generation and Optimization of interpolation approximation algorithm based on Laser Icon Contour Generation
Authors: Zhou Beifen , Bai Yalong , Feng Xinyuan
Published: April 2021

Point-by-point comparison interpolation is a widely used algorithm in laser marking system. This algorithm plays a very important role in controlling the laser trajectory and fitting the image trajectory. Because the point-by-point comparison interpolation method has the characteristics of intuitive operation, uniform pulse output and convenient adjustment, it is a kind of interpolation algorithm which is more suitable for the application of marking machine system. In order to improve the marking efficiency of vector text in laser marking system, by analyzing the outline structure of TrueType font and the properties of Bezier curve, an optimization algorithm for straight line approximation of TrueType font outline is presented, and the theoretical analysis and experimental verification are carried out. Firstly, the Bezier curve in the TrueType font outline is segmented according to the deCasteljau recursive algorithm, and then the curve is replaced by the connection of the head and tail control points. Finally, the approximate line segment is interpolated to generate marking data, and the straight line approximation outline is compared with the standard TrueType font outline. The results show that under the condition of satisfying the accuracy, the algorithm has the advantages of simple calculation process and a small number of nodes, and improves the marking efficiency of vector text. The traditional point-by-point comparison interpolation algorithm has some problems such as low precision and slow speed. In order to improve the performance of the algorithm, the traditional point-by-point comparison interpolation algorithm is improved, and the calculation and simulation are carried out. The results show that the accuracy and speed of the improved interpolation algorithm are obviously improved. The patch is extracted from the point cloud data, and the feature patch is generated by patch growth and fusion, and the feature line is constructed quickly according to the proposed patch two-way index method, and finally the point cloud plane contour is generated. Experiments show that this algorithm can generate point cloud contours quickly, accurately and effectively.
Research on Economic Returns of Distributed Photovoltaic Power Generation Projects in Hunan
Authors: Zhu Yingtong , Jie Xiaowen
Published: April 2021

Photovoltaic power generation has been practiced in the application field in recent years. Distributed photovoltaic power generation has now entered the stage of large-scale, and government subsidies at all levels are being reduced. Will distributed photovoltaic power generation projects still have the necessary investment and development advantages in the future? We selects Hunan Province, China as the research area and analyzes the economic returns and development of distributed photovoltaic projects. The method of esmiting economic returns is the IRR, NPV and payback period. According to the analysis conclusion, it is believed that distributed photovoltaic power generation still has advantages, and the investment strategy and suggestions for distributed photovoltaic power generation projects in Hunan.
Research on Vehicle Damping Control Strategy Based on In-Arm Torsional Electromagnetic Active Suspension
Authors: Zhang Hongyang , Xiang Weier , Zhou Kailai , Xu Lin
Published: April 2021

This paper proposes a new control strategy based on the In-Arm Torsional Electromagnetic Active Suspension (ITEAS), which can improve the vehicle ride comfort through adjusting the damper in ITEAS to optimize the kinetic characteristics of the vehicle composed by two ITEAS systems. Firstly, the structure and principle of the new type system is introduced followed by the description of the vehicle and the damper in ITEAS. Secondly, according to theoretical mechanics and fluid mechanics, the dynamic model of ITEAS system and the hydraulic model of shock absorber are established under forced vibration. Then, the PID control simulation model of the front suspension is established in AMESIM with a passive model as reference, due to the special assemble features of the vehicle. The rear suspension adopts predictive control method and the simulation model is built in MATLAB/SIMULINK, whose theory can be summarized as adjusting the duty ratio of the valve in damper to improve the stability of the vehicle under the condition that the road surface information is already known. Lastly, this paper tests the suspension characteristics on the MTS bench, which verifies the proposed control method improves the ride comfort performance and the feasibility of predictive system.
Experimental Research on Partial Discharge of High Voltage Direct Current
Authors: Zhang Jian , Xu Minhu , Guo Yun , Zhang Kexin , Liu Heqian , Zhao Xiangyu
Published: April 2021

Under the action of long-term high-voltage DC voltage, the insulation of electrical equipment is inevitably aging, and it is necessary to monitor its insulation status. Since insulation defects of different nature damage electrical equipment to different degrees, the identification of defects is very important. To this end, a DC partial discharge detection system based on AC partial discharge detection equipment was built, focusing on key issues such as the choice of test power supply, the choice of test frequency, and the choice of pressurization methods. The successful completion of the on-site partial discharge test of UHV converter transformers has provided valuable practical experience for the future on-site partial discharge tests of UHV converter transformers, and provided important tests for the establishment of on-site partial discharge test standards for UHV converter transformers. in accordance with.
Research on Laser Ablation Technology in the Material Interaction of Two-dimensional Axisymmetric Ablation Model
Authors: Wang Yaode , Li Changli
Published: April 2021

In order to explore the mechanism of interaction between nanosecond pulsed intense laser and material, the paper established a two-dimensional numerical model, using finite difference method to numerically simulate the temperature field of nanosecond laser pulse ablation of metal aluminium. By comparing different pulse widths, the temperature field caused by the laser under the spot and energy evolves with time. It is found that the temperature in the early stage of the pulse rises faster than in the later stage. The isotherm diagram shows that the centre temperature rises fastest, the ablation profile is similar to the shape of the laser beam, and the ablation depth reaches 1 -5μm. The longer the pulse width, the narrower and deeper the ablation, the larger the spot, the wider and the shallower the ablation. The calculation results show that, compared to the uniform distribution, when the laser has a Gaussian distribution, the target aluminium centre can be obtained the higher the temperature rise, the more prone to ablation and the shorter the melting time of aluminium. The model established in this paper can be easily extended to three-dimensional situations.
Multi-agent time-varying formation control based on consistency
Authors: Wang Xinyi
Published: April 2021

This paper studies the dynamic time-varying formation control of multi-agent systems. Aiming at the unmanned vehicle systems, based on the static time-varying formation in literature [18], a multi-agent dynamic time-varying formation control based on consistency is put forward. Additionally, the sufficient conditions for the agreement and the steps for solving the control parameters are given. The simulation is conducted to prove the effectiveness and robustness of the theoretical results.
Multi-Antenna Selection for Double Spatial Modulation
Authors: Fu Dan
Published: April 2021

In this paper, to exploit the spatial domain of transmit antennas (TAs) for the transmit diversity gain in the double spatial modulation (DSM) system, a new scheme of multi-antenna selection for DSM (MAS-DSM) is designed. In the MAS-DSM system, the number of TAs are grouped into n groups, each of which corresponds to an sub-system of DSM. More specifically, a transmitted spatial vector is constructed by two spatial vectors (SVs). For the achievability of transmit diversity gain, one of the two SVs is obtained by using n antenna index (AI) vectors to modulate a data symbol, another of them is obtained by multiplying with a rotation angle after another n AI vectors to modulate another data symbol. Finally, the spectral efficiency and the average bit error ratio (BER) are analyzed. Simulation results by using Monte Carlo demonstrate that the proposed MAS-DSM system has better BER performance compared with the conventional spatial modulation schemes in wireless communication network.
Research on defect pattern recognition of Light Guide Plate based on Deep Learning semantic Segmentation
Authors: Liu Linlin , Zuo Haiyu , Qiu Xiao
Published: April 2021

Because the defects of the light guide plate are still extremely small under the image taken by the high-resolution industrial camera, and the characteristics of different defects are different, as well as the texture characteristics of the whole light guide plate, such as dense and uneven distribution of light guide points, the traditional image processing and detection methods require experienced visual engineers to do a lot of feature extraction algorithm programming and expensive code maintenance. The accuracy is low and the stability is poor. However, the surface defects of the light guide plate are still mainly detected by artificial visual observation, and only a few manufacturers use traditional image processing methods to detect them. For this reason, a defect detection method based on deep learning semantic segmentation is proposed. In this method, the defect features of the light guide plate are extracted by self-learning by training the neural network, so as to avoid the complicated programming work of feature extraction algorithm. First of all, the defects of the collected light guide plate are marked to make a sample set; secondly, the pre-trained pyramid scene parsing network (PSPNet) is used to retrain the labeled samples; furthermore, the defect detection of the light guide plate is realized by using the trained model. The single deep learning semantic segmentation defect detection method usually can not meet the needs of industrial applications, finally, it is necessary to combine the simple machine vision method to judge and screen all the suspected defect regions detected by the deep learning semantic segmentation method. The experimental results show that the detection rate of bright spots, dark spots and scratches is as high as 96%, which can basically meet the requirements of industrial inspection.
Preliminary Study on Electromagnetic Thermal Coupling Numerical Simulation Technology of Static Inductor
Authors: Sun Qian , Yuan Hongli , Zhou Hong
Published: April 2021

In this paper, the load transfer analysis method is used. Firstly, the magnetic thermal coupling analysis model is established and the material parameters are determined in ANSYS software. Secondly, the direction of applied current is determined by studying the influence of current direction on the temperature field in the electrified wire. Then, the relationship between current frequency, current magnitude and temperature field and the change of temperature at typical points with time are studied respectively. Finally, the parameters of temperature field for high frequency induction heater to produce better plastic deformation are determined. The research content of this paper can provide a reference for the subsequent research of electromagnetic thermal structure coupling numerical simulation technology of mobile inductor.
Reflected Backward Doubly Stochastic Differential Equations with Monotone Coefficients
Authors: Li Yunhong , Wei Lifeng
Published: April 2021

In this paper, we prove the existence and uniqueness of the solutions to reflected backward doubly stochastic differential equations (RBDSDEs for short) with monotone coefficients. The “reflected” keeps the solution above a given stochastic process. We get the uniqueness and existence by penalization.
Research progress of TiO2-based photocatalytic materials
Authors: Zhu Li
Published: April 2021

TiO2 is the most widely studied photocatalyst, which has a good application prospect in the field of environmental pollution control and has always been a hot spot of photocatalytic materials research. The crystalline structure, surface morphology, and optical properties of TiO2-based photocatalytic materials prepared by different methods are different, and thus exhibit different photocatalytic properties. In this paper, the research progress of TiO2-based photocatalytic materials in China and abroad in recent years was reviewed based on the common preparation methods.
Attack and Defense Countermeasures of cognitive radio
Authors: Li JinFeng , Sun Bingcheng , Cui Hongfeng
Published: April 2021

with the development of cognitive radio theory and technology, its application in various fields will be more and more extensive. She’s trying to bring AI technology to the Internet. In this paper, the attack and defense of cognitive radio will become more and more intense. The mobile communication process of cognitive radio is summarized, and the attack and Defense Countermeasures of cognitive radio are analyzed.
Design of a new buoy night display system
Authors: Chen Wenhao , Li Xiaolong
Published: April 2021

This article through the analysis of the current navigation safety, combining the AIDS to navigation problems, in the light of the short of the AIDS to navigation, using the right technology, the display system to carry on the design of a new type of buoy night, through the design of various modules, the organic combination of display system, form a new type of buoy night finally to the feasibility analysis of system, ensure the accuracy of the model and feasibility. Among them, the model control box module, light emitting component module, the solar panel module, photoelectric sensor module, power module system design circuit design together, make the buoy nighttime display system has a good stability, high consistency, high cost performance, light range, fast response, electromagnetic compatibility and reliability, the product in ensuring the stability of the whole system work at the same time, maximum limit reduce the power consumption of the power supply. It improves the ability of buoys to be identified by ship pilots at night and strengthens the guidance of channel ships, ensures navigation safety and reduces the property loss of ships and navigation marks, which is of extremely high social value and practical significance for the improvement of navigation marks.
The Research on Blended Teaching in Vocational Colleges Based on Smart Campus
Authors: Huang Zhiyan
Published: April 2021

Blended teaching is an “online” + “offline” teaching that combines the advantages of online teaching and traditional teaching. Through the organic combination of the two forms of teaching organization, learners’ learning can be guided from shallow level to deep level to deepen the understanding of learning. Teachers no longer occupy students’ learning time in the classroom, and they can promote the development of their individualized learning, and let students acquire more learning knowledge or allow students to learn independently in their spare time. This article is to mainly analyze the application of blended teaching in vocational Colleges under the background of smart campus.
Microstructure and properties of laser hybrid welding joint of AH36 marine steel
Authors: Pei Yingchao , Xia Dianxiu , Wang Qichen , Shang Chengjia , Sun Weihua , Wang Shouren , Han Qin , Wang Dongyue , Han Zhengpeng
Published: April 2021

AH36 Marine steel 10mm thick was welded by Laser-MIG hybrid welding process, and the structure and properties of the arc zone and laser zone of the Laser-MIG hybrid welding joint were studied respectively. The results show that the width of welding seam and HAZ in arc action zone is obviously larger than that in laser action zone. The microstructure of the weld was mainly acicular ferrite, bainite, martensite and grain boundary ferrite, and the content of martensite and bainite in the laser action area was relatively higher. The microstructure of the coarse grain zone is mainly thick lath martensite, granular bainite and acicular ferrite, and the microstructure of the arc action zone is relatively larger. The microstructure of the fine crystal region is mainly fine ferrite and pearlite. The hardness of arc zone and laser zone is distributed symmetrically in the weld center, the lowest hardness occurs in the weld center, and the high hardness occurs in the weld HAZ. The tensile specimens in the arc zone were fractured near the HAZ and the laser zone was fractured on the base metal far away from the weld. The lowest value of impact absorption work at 0°C in arc action area and laser action area appeared at the fusion line +0.5; the highest value of impact absorption work at 0°C in arc action area appeared at the fusion line +1.0, the fusion line +1.5, and the fusion line +2.0; the highest value of impact absorption work at 0°C in laser action area appeared at the fusion line. The impact absorption at 0°C in the laser action area is higher than that in the arc action area.
Application of Acoustic Spectrum Analysis in Detection of Porcelain Post Insulators Based on a portable insulator detection equipment
Authors: Wang Anli
Published: April 2021

Fault detection of porcelain post insulators has always been the research direction of power industry. At present, the related equipment for flaw detection of porcelain insulators still has some defects, such as high equipment cost, complex operation and poor detection effect. For the fault detection of porcelain post insulators, this paper will put forward a complete set of fault detection methods based on the application of acoustic spectrum analysis in the fault detection of porcelain post insulators. The equipment used is a portable insulator testing equipment independently designed by the research team based on the basic principle. Based on this method, a large number of comparative experiments and testing applications have been carried out, which verifies the effectiveness and reliability of the vibroacoustic testing method in the detection of porcelain post insulators.
Research on Intensive Power Resource Regulation Algorithm
Authors: Qiu Fei
Published: April 2021

The paper takes the economic load distribution of the power system as the objective function, and establishes a mathematical model with economy, environmental protection, and reliability as system variables. It adopts the hierarchical thinking of control theory, uses multi-particle swarm multi-level optimization algorithm, and combines power distribution the characteristics of the network take the optimal value of each subsystem as the individual optimal value of the current particle, and perform the second particle swarm optimization to increase the probability of effective solution generation in the iterative process. Using multi-particle swarm hierarchical distributed algorithm, effectively improve the optimization accuracy of the objective function, the convergence speed and the number of times of convergence to the global solution. This paper focuses on power system optimal dispatch, fully considers the relationship between each system, and uses particle swarm optimization algorithm to obtain the optimal allocation of power resources. At the end of this paper, two typical IEEE power distribution networks are simulated and calculated. The calculation results show the superiority of the algorithm in calculation accuracy and convergence speed.
Summary of PID Control System of Liquid Level of a Single-Capacity Tank
Authors: Jiang Pei
Published: April 2021

Liquid level is one of the control parameters widely used in industrial production. Accurate control of liquid level bears on the quality, efficiency and market of products, as well as the effect and safety of production. Therefore, the research on liquid level control has practical significance and broad application prospects. In view of this, this article firstly briefly analyzes the characteristics of the single-tank water tank level system, and then focuses on the realization of classical, fuzzy and neural network PID (Proportion Integral Differential) algorithm for the single-tank water tank level system. Finally, the validity of algorithm is proved by the system real-time simulation curve, which provides a more comprehensive reference for similar control systems.
Cleaning Device for Inner Wall of Vertical Cement Tank Based on Electromagnetic Principle
Authors: Yang Shenyang , Lv Shaowei , Yu Longkun
Published: April 2021

In the process of cement storage in cement tanks, the cement on the inner wall is affected by various factors, which will cause hardening. Cement hardening will cause a series of problems such as the decrease of effective storage capacity of cement wall. Therefore, in the mortar production process, the cement tank needs to be cleaned regularly. In order to solve the above problems, the device is designed. The device adopts intelligent design and cleans the inner wall of cement silo by spiral cruise cleaning method to realize the effective cleaning of cement silo.
Research on Intelligent Charging Control System of Electric Bicycle
Authors: Nie Gaosheng , Liu Yonghua
Published: April 2021

This article designs a basic electric bicycle charging management system, which can solve the problem of difficult charging of electric bicycles and completely eliminate the safety hazards of private wire connection. The electric bicycle charging management system is divided into charging station intelligent terminal, server background, WeChat client, web management terminal, etc. The intelligent terminal of the charging station adopts the RS-485 bus to realize the communication with the intelligent charger and grasp the charging status in real time. The back-end server adopts the MVC architecture, which provides a query interface for the client and the web management back-end to monitor the charging status in real time. The management system also implements the WeChat payment function, which can realize charging on time and according to the amount. Practice has proved that the charging management system can well solve the current charging disorder and has a good market prospect.
Study on breaking mechanism of chestnut shell based on finite element analysis
Authors: Yang Xueyin , Qi Yanxing
Published: April 2021

Chestnut shell breaking is an important part of chestnut processing. According to the measured physical parameters and geometric dimensions, the solid model of chestnut was established by ANSYS software, and the chestnut was divided into appropriate element grids. The stress and strain of chestnut shell breaking were analyzed along different loading directions. The results show that the y-direction loading is the most labor-saving, and the x-direction loading is the best, so as to improve the quality of chestnut shell breaking It provides a theoretical basis for the further processing of chestnut.
Experimental and Theoretical Analysis of the Factors Influencing the Flow-out Rate from a Bottle
Authors: Jiang Yuxin
Published: April 2021

While looking for parameters that may affect the experiment results, one of the basic experimental principles can be adopted: the principle of controlling a single variable. This experiment is centered on the flow rate of the liquid in the plastic bottle, and the fixed value that remains unchanged is the physical properties of the bottle itself and the liquid. The density of the liquid and the angle of the bottle are two factors that could affect the flow-out rate. The ten different angles from 0° to 90° are chosen to be observed. And five different densities of alcohol are chosen to be tested as well. Under reasonable error control, the angle of the bottle body can be obtained when the liquid flow rate is the maximum. Based on the experimental derivation process recorded in this article, the basic knowledge of statistics is used, combining with as much precision measuring equipment as possible. Then, the Bernoulli equation is also used to calculate the ideal value, which is also compared with the actual value, to get the impact factors. The experimental results are scientifically analysed and deduced, and finally, substantial results are obtained.
Research on flexible sensor based on 3D printing manufacturing by fused deposition molding
Authors: Song Dongping , Xu Xinghua , Zhang Yongkang
Published: April 2021

a flexible capacitance and resistance sensor is studied, which is manufactured by single step using 3D printing technology of fused deposition molding. Compared with the existing manufacturing technology of flexible sensor, the 3D printing technology has the advantages of low manufacturing cost and simple manufacturing process. The capacitive force sensor and the resistance temperature sensor are fabricated by melting deposition and forming 3D printing respectively using the wires of conductive and dielectric materials. The capacitive force sensor adopts parallel plate structure, and its relative sensitivity can reach 0.088% / N. the relative sensitivity of the resistance temperature sensor can reach 2.2% / °C. The resistance and capacitance sensors can be used as touch sensors, which have great potential in the fields of electronic skin, intelligent wearable devices and soft robots.
Research on the Vibration Response of Cylindrical Vessel under Explosion Shock Wave in Confined Space
Authors: Liu Yalei , Gu Xiaohui
Published: April 2021

The experimental research is carried out on the shock wave vibration response of the cylindrical explosive container under the explosion at the center point. First, a horizontal flat-head cylindrical explosion vessel was designed and the shock wave vibration test placement was carried out; secondly, the explosion shock wave vibration test in a confined space was carried out under different charges; then the vibration conditions at several typical locations were carried out Comparative measurement and analysis of its vibration frequency characteristics. The test results show that the shell vibration acceleration value at the measuring point is related to the charge amount and the distance from the explosion center; the shell vibration frequency close to the middle ring is dominated by the natural fundamental frequency, and as the shell moves away from the center to the ends, The low-frequency vibration gradually increases, and the vibration frequency component of the container head is single, and its main frequency is determined by the natural frequency of the head.
GIS vibration principal analysis and modeling
Authors: Qu Bin , Zhang Li , Fang Qiong , Chen Rong , Han Bin , Wang Xiaopeng , Wang YanHua
Published: April 2021

Based on the most basic electromagnetic theorem, this paper analyses the most basic principle of GIS vibration formation. The characteristic formulas of magnetostriction and Ampere force vibration are deduced, and the characteristic frequencies of them are both 100Hz. Combined with the structural characteristics of GIS, this paper analyzes the two common vibration models of induced eddy current and induced circulation, and calculates their analytical formulas, which can easily calculate the induced current, and provides a reference for GIS vibration research.
GIS vibration test method and characteristic signal recognition
Authors: Qu Bin , Wang Yongning , Zhou Liangsheng , Wang Kun , Wang Ziyue , Wang Jian , Chen Haowei
Published: April 2021

Based on the characteristics of GIS insulation and mechanical fault types and practical measurement experience, two typical vibration measurement methods, direct measurement method and natural frequency measurement method, are proposed in this paper. Then, based on the real data of experiment and field measurement, the vibration signals of typical insulation fault and mechanical fault such as spike discharge and end cover looseness are compared, analyzed and summarized, and their respective data characteristics are extracted, which can provide the basis for the determination of GIS vibration fault types.
A Method Based on Initial-phase-point Analysis for Determining the Fault Mode of the Unbalanced Vibration of Turbine Rotor
Authors: Wen Xiankui , Liu Shi , Qing Shaowei , Li Xiang , Deng Tongtian , Zhang Shihai
Published: April 2021

Rotor imbalance is one of the common faults of turbines, but traditional analysis methods are difficult to distinguish different fault modes, e.g. the original imbalance of rotor and the thermal bending of rotor. By introducing the concept of initial phase point, a rotor imbalance model is established and corresponding identification method for original imbalance and thermal bending is developed. Through the analysis and processing of practical cases, it is proved that this method is effective and can carry out the fault diagnosis of rotor unbalance accurately.
Collision Simulation and Optimization Analysis of Vehicle Thin-Walled Components Based on Trolley Test
Authors: Hu Yi , Liu Li , Chen Mengwei
Published: April 2021

Based on the response data of the frontal impact test of the trolley, the frontal impact simulation and analysis of the double-tube model of the trolley were carried out using finite element software. Starting from the thin-wall deformation mode, acceleration and energy curve changes as response indicators, the error between simulation and experiment is studied. With the goal of improving the simulation accuracy of the model, the influence of strain rate effect on the collision response is studied, and the deformation mode and acceleration curve are compared with those without strain rate and actual vehicle test. The final result shows that considering the strain rate effect is obviously better than not considering the strain rate in terms of the acceleration peak and the number of thin-wall deformation folding.
Numerical simulation on the noise reduction of underwater pile-driving using a bubble curtain
Authors: Gao Yuning , Ma Jun , Ding Yue
Published: April 2021

Aiming at the problem of heavy noise pollution caused by underwater piling operation and, to protect the marine ecosystem near the construction site, this paper discusses the attenuation effect of bubble curtain system on underwater noise generated by piling operations, basing on the previous research on underwater bubble sound attenuation and the attenuation characteristics of sound propagation of different media. Using COMSOL Multiphysics finite element analysis software, the noise field of underwater piling and the model of underwater bubble curtain are established to study the influence of the bubble curtain on the pressure peak values at different depths generated by the same noise source, and the attenuation effect of the bubble curtain on underwater noise is discussed. The results show that the peak sound pressure level of underwater noise can be attenuated by about 8 dB using the bubble curtain.
Design of a new type of F-COFT controlled BUCK-BOOST converter
Authors: Chen Guanghui , Huang Gege , Zhang Ke
Published: April 2021

As an important method of pulse frequency modulation (PFM), constangt off-time (COFT) is widely used in switching power. However, the switching frequency changes with the input and output voltage, which increases the power consumption of the switching power and is prone to high electromagnetic interference (EMI). Therefore, a new fixed frequency COFT control method (F-COFT) is designed. By designing a charging timing circuit that carries input and output voltage information, the input and output voltage information is fed back to the timing module to realize dynamic adjustment of the constant-off time to ensure the stability of the frequency and eliminate the influence of frequency changes on the circuit. Through LTSPICE simulation, the feasibility of the scheme is verified.
Intelligent recognition-based unloading device design for university container logs
Authors: Yi Jiale
Published: April 2021

Timber resources are strategic resources for China’s national economic development, and the traditional container transport log unloading method is inefficient and requires manual handling, but due to the increase in residents, infrastructure efficiency and other issues, the log handling efficiency also needs to be greatly enhanced, so a high-efficiency, energy-saving and environmentally friendly log loading and unloading device that can work autonomously has become the urgent need of the moment in ports, wood yards and other places.
Research of Integrated Impeller Modeling and Five-axis Machining Technology based on Reverse Engineering
Authors: Zhao Xi , Pan Junbing , Li Lin
Published: April 2021

Five-axis NC technology and reverse engineering provides critical support for industrial development and has been an important subject for scholars to study. This paper focused on aviation impeller and discussed the integrated application of NC machining technology and reverse engineering. It collected the shape point cloud data of the impeller through 3D scanner and Geomagic Wrap software and completed the reverse parametric modeling using Geomagic Design X software. The impeller model is complicated in structure which is hard to machine on three-axis and four-axis machine tools, hence developed a five-axis machining program by using the NC programming software of Hypermill and carried out actual machining test. The results showed that the error between the machined sample and the research model is less than 0.05 mm, which can satisfy engineering requirements. It also indicated that the NC program developed by Hypermill software has high machining accuracy and safety, and the integration of reverse engineering and five-axis technology presents positive significance to the innovative design and machining for complicated engineering surfaces.
Research of An Automatic Mopping Assistant Robot
Authors: Zhao Xiaoyang , Lu Ming
Published: April 2021

This paper proposes an automatic mopping assistant robot, it has functions of auto-following, providing clean water, storing up sewage and washing mops. Firstly, to get the goal of auto-following, the robot has 1 ultrasonic module and 2 infrared modulesthat are connected with 1 Arduino motor driver that on 1 Arduino UNO board, the former for distance, the latter for direction, they cooperate to give robot ability of following people and keeping a safe distance fromusers. Secondly, interms of the mechanical structure, the robot is designed with 3 water sinksthat areinterconnected, which can provide water for cleaning mops at any time;finally, There is a cross-shaped brush on bottomof the cleaning sink, so when anelectric mop is put on it and turned on,the mop will be cleaned. The experimental results show that the robot achieves the expected function and runs well.
Simulation Analysis of Vortex Tube Parameters for Desalination Device Using Ship Exhaust Heat
Authors: He Shiji , Zhou Changqing , Zhang Wenbo , Liu Bingjin , Cui Yue
Published: April 2021

The waste heat energy of diesel exhaust of current small and medium-sized ships is a big waste, while the distillation method in marine desalination is energy-intensive and its equipment is large, as well as the reverse osmosis method is seriously polluting. In order to solve the above problems, a waste heat desalination device for small and medium-sized ships is designed based on the cold-heat separation effect of vortex tube. In this paper, based on the study of the vortex tube working principle, the parameters of the vortex tube are designed and calculated, and the optimum inlet temperature at a certain pressure is calculated to further determine the design parameters of the whole device. According to the basic laws of thermodynamics, a mathematical model is established to describe the changes in the state of diesel exhaust.
An innovative design of mechanical auxiliary device for assisting flexor and wears
Authors: Zhang Jiankang , Yan Zhen , Chen Yijing
Published: April 2021

Today, the aging of the population is becoming more and more prominent, and the aging of the population brought about by the social, health and other problems on the family and society for the elderly function also has a higher and higher requirement. Through research and literature review, most of the elderly have the symptoms of leg and foot inconvenience or nape and lower back pain, which brings great obstacles for them to wear pants and socks with bending body. However, it is difficult for the accessory products of flexor wearers sold on the market to truly complete the function of non-flexor movement. For this reason, this project designed a device that can help the elderly to complete the movement of wearing pants and socks without bending down. Moreover, through multi-stiffness adjustment, linkage drive structure is designed to realize the integrated wearable process. According to ergonomics, relevant design is made for the device size, and the combination of multiple adaptive modules can realize the adaptive matching for the elderly with different heights and body shapes.
Research on auxiliary bed - lifting device for the elderly
Authors: Yang Yuanhang , Qi Lei , Jing Haonan
Published: April 2021

Although there are devices to assist the elderly to get out of bed in China, most of them are aimed at the disabled elderly or still need artificial assistance. For some old people with certain activity ability, there is no appropriate auxiliary equipment at present. Based on this background, the electric push rod and gear system are used to realize the back lifting, leg bending and auxiliary standing functions of the elderly when they get up and lie down. The matching design of connecting rod mechanism and gear mechanism is adopted to meet all the needs of the elderly when they get up and lie down with a simple mechanism.
AGV of Mechanical Auxiliary Parking Based on Self Driving
Authors: Sun Haotian , Zhang Wenbo , Xie Anbo
Published: April 2021

In order to solve the problem of parking difficulties in urban residential areas, a small auxiliary parking device is proposed. Starting from solving the social pain points such as unreasonable parking space planning, residents’ random parking, and reducing parking difficulty, it achieves the effect of assisting parking space planning and reducing parking difficulty. The device mainly provides power through the motor, and drives the drum to realize binary control by controlling the steering wheel of the vehicle owner, that is, controlling the switching of the whole movement, and the switching of the front back and left right of the control device. By pressing the spring switch on the wheel, the front control motor drives the gear clutch device to complete the bidirectional switching from left and right movement to back and forth movement. Through the shear fork supporting mechanism and separate self-locking slide rail, the car is lifted and the parking device is driven away.