bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Pricing Strategy of Three-echelon Dual-channel Supply Chain under Market Equilibrium
Authors: Sha Jin , Zheng Sisi
Published: May 2021

The healthy and sustainable development of supply chain must be based on the consideration of both enterprise profit and consumer benefit and only the market behavior under perfect competition environment might maximize the social total welfare. The market equilibrium in perfect competition market is the premise of maximizing the sum of consumer and producer surplus. Taking the pricing strategies of supplier, manufacturer and retailer as research objects, market demand and supply functions considering the effect of different channel prices is built, and a three-echelon dual-channel supply chain model is constructed. Then, the optimal pricing strategies of decentralized and integrated three-echelon dual-channel supply chain are developed by applying two-stage stackelberg game theory and overall revenue maximization principle. Furthermore, the conditions of optimal equilibrium prices existing with the restriction of market equilibrium are discussed, and the expressions of the optimal equilibrium prices about different supply chain structures are analyzed. Eventually, we use method of numerical analysis to explain the pricing strategy we analyze.
Research on Decision and Coordination Model of Fresh Products Supply Chain with Quality and Price
Authors: Liu Qianwen , Zhang Shun , Zhao Chen
Published: May 2021

With the adding emphasis on the fresh products quality, the competition among suppliers has been expanded from pure price competition to the competition of the quality and price of fresh products. By introducing the price impact coefficient and the influence coefficient of quality of two variables, this paper analyzes the game equilibrium of a supply chain respectively in the centralized, decentralized and coordination decision-making model. Through numerical analysis, the paper analyzes the retailers, manufacturers and the change of each decision variable value of the supply chain. The results indicate that the price of sales and the quality of fresh food are related to the variables in the three different decision-making model, and when the revenue sharing coefficient and cost coefficient are in a rational range, after revenue sharing cost sharing contract is coordinated, retailers must pay fixed costs to compensate for manufacturers. The whole supply chain profit is greater than the decentralized decision-making gains after the coordination.
Stability of Linearly Switched Demand Dynamics in Supply Chain Based on Inventory
Authors: Wang Yubao , Wang Weihua
Published: May 2021

The organized supply chain is one of the best competitive ways for the retailer. The dynamics and stability of a supply chain under inventory and price with the feature of piecewise linearity is analysed. This switched linear model composed of four subsystems for the first time. On the basis of linear switched model, some stabilities are derived and the global dynamic behavior is theoretically examined. It is illustrated that the combination of the stock-dependent demand function and inventory can bring about the stability result under, but also arise more complicated nonlinear fluctuations under bη ≥ 1
Research on Multi-criteria Material Selection of Automobile in Full Cycle under the Background of Green Manufacturing
Authors: Ding Zhensen , Fang Haifeng , Yao Zhanhui , Liu Jinzhou , Wang Jia
Published: May 2021

Under the background of the continuous strengthening of green manufacturing, the automobile industry, as a typical representative of the industry, will be an important battlefield for the green development of China’s industry. In addition, with the emergence of new alternative materials for automobiles, the selection range of materials for automobile parts is gradually expanding. Literature from year 2009 until year 2019 were collected which is focused on related automotive material selection. It’s worth noting that the concept of “green manufacturing” was proposed in 2018. It is found that the selection criteria of automobile materials have been expanded from only focusing on mechanical properties to economic performance, technological performance and environmental performance. The multi-attribute material selection method is emerging because of the more complicated material selection caused by the increase of environmental attributes, which also brought manifest divergences in the selection of secondary indicators and the setting of weights. According to the practical application, the optimization measures related on the selection basis of secondary indicators and setting weights from the perspective of producers and consumers in the whole life cycle were proposed.
The Research on Influencing Factors of Autonomous Vehicle Usage Behavior: Root Analysis Based on UTAUT2 Model
Authors: Zheng Hao , Gao Hongyan
Published: May 2021

As a new sustainable means of transportation, how to successfully make autonomous vehicles accepted and used by the public is a key challenge for research. Based on the Unified Theory of Acceptance and Use of Technology 2 (UTAUT2) model, the research took the social media platform as the data source to conduct a grounded analysis, comprehensively considered the interaction of individual internal factors and external environmental factors, and combined the technology acceptance field, user behavior field, sociology, psychology, marketing and other disciplines to build an influencing factors of autonomous vehicle usage behavior model, which is suitable for Chinese market. The study found that performance expectation, effort expectation, social impact, facilitating conditions, price value, hedonic motivation, perceived risk and perceived trust influence individuals’ intention to use autonomous vehicles. Facilitating c zV Conditions, perceived risk and intention affect individual’s usage behavior. The level of individual knowledge plays a regulatory role in the use behavior. The results provide a decision basis for the government and enterprises to effectively promote the use of autonomous vehicles.
Research on C-end Customer Demand Based on Cluster Analysis
Authors: Wei Zhenlin , Wang Lan , Ouyang Yuzi
Published: May 2021

With the rapid development of Internet economy, the problem of “last kilometer” distribution difficulty in B2C e-commerce has become one of the pain points of the whole industry, and improving the customer service level of C-end has become an important content of enterprise development. The change of C-end demand distribution will have a significant impact on the location of end-of-line service outlets, so this paper studies the spatial distribution of C-end customer demand points. According to the significant spatial clustering of C-end customer demand points in geographical space, K-means algorithm and DBSCAN algorithm are selected to cluster the demand points. The clustering results of the two algorithms are evaluated by the internal distance and the average distance between clusters. The comparison results show that k-means algorithm has better clustering effect on the demand points, and its clustering results can also be used as the end the main measurement index of service network layout provides services for terminal service network location.
Comparative Analysis of Prophet and LSTM Model in Drug Sales Forecasting
Authors: Meng Jie , Yang Xiao , Yang Chengwei , Liu Yang
Published: May 2021

With the rapid development of China’s pharmaceutical industry, accurate prediction of drug sales has become the key to enterprises’ competitiveness. Sales forecasting research has very important value for strategic decisions and improvement measures made by enterprises. We studied mainly two machine learning methods of pharmaceutical sales prediction in this paper, analyzed deeply the prophet model and LSTM, and carried out a comparative experiment on these two methods using real sales data. The experimental results show that the LSTM model is more accurate than the Prophet model on drug sales forecasting.
Study of Eco-evolution Path of Home Textile Industry under the Background of Internet Plus
Authors: Zhao Hongshan , Ma Lin
Published: May 2021

Under the background of “Internet+”, home textile industry witnesses the revolutionary stages of value creation, value realization and value transmission. During the revolution, the industrial value chain has been reset, all-media transmission, C2B mass customization, O2O mode and collaborative creation of intelligent value, and other innovative development paths have emerged. Through the study of the eco-evolution path of home-textile industry, the current paper explores how traditional home-textile enterprises upgrade themselves properly in the Internet era, which can provide references to other traditional enterprises in need of upgrading and development.
Typical Zone Division of Karst Kevelopment in China
Authors: Liu Yukang , Li Hailing , He Yingding , Cao Xianfa
Published: May 2021

Determining the typical area of karst development in China would provide positive reference for theoretical research of engineering geology in karst areas in China. By quantitative or semi-quantitative analyzing on the distribution characteristics, climatic conditions and formation lithology of carbonate rocks in China, regional difference characteristics of karst development in carbonate rock regions in China is evaluated, and finnally the representative karst zone in China is reasonably and theoretically delineated and demonstrated. Results show that: the pure Carbonate rocks in southwest of China in tropical and subtropical climate zone which are very favorable for karst development, distributes continuously and massively, and therefore can be considered as the most typical karst area,. this is also a very explanation that karst morphology develops completely. Especially, karst in the zone including Guangxi Zhuang Autonomous Region, southeast and north-east of Guizhou province, and southeastern of Chongqing Municipality, is the most representative karst region in southwest of china because of its the purest carbonate rocks.
Multifractal analysis of spatial–temporal characteristics in the Alpine–Himalayan seismic zone
Authors: Chen Jiemin , Yan Zelin , Xu Linfeng , Liu Zhixin , Liu Yan , Tian Jiawei
Published: May 2021

The occurrence regularity and propagation mechanism of seismic activity are complicated and variable to be described by existing models. This paper presents a multifractal analysis of the Alpine–Himalayan seismic zone in time–space series. The multifractal spectrum of energy released from the seismic zone is obtained from different angles. Results show that earthquakes in the seismic zone possess complex multifractal characteristics in time–space series. Moreover, the clustering feature of the seismic activity intensity in the seismic zone is similar among the time–space series.
Artificial Neural Network Plan for Transmission Tower Structure Safety Assessment
Authors: Sun Mi , Xie Jinghai , Jiang Yu , Su Dongyu , Lu Shihua , Guo Jia
Published: May 2021

The security of transmission tower structure is the foundation to ensure the safe operation of power grid. The research of fuzzy qualitative assessment method for the structural health of transmission towers is the basic work of large-scale digital power grid engineering. In this paper, artificial neural network (ANN) is used as a generalized tool for structural health assessment of transmission towers. The feasibility of using artificial neural network to qualitatively evaluate the structural health of transmission towers is verified by numerical simulation data. In order to train the artificial neural network, the displacement, stress and other signals generated by the finite element model are calculated and used as the training input of the artificial neural network. The detailed stress results of the finite element model are calculated as the qualitative evaluation basis of the structural health, and the training output of the artificial neural network is generated. By the same method, the test set is generated, and it is found that the artificial neural network is feasible for the fuzzy qualitative assessment of the structural health of transmission tower, and the misstatement rate is less than 5%.
Research on the energy efficiency of the multiphase nanosecond pulsed discharge system with TiO2 photocatalysis
Authors: Che Rui , Sun Ming , Xu Haiyang
Published: May 2021

Energy efficiency of the system is always paid more attention in the research of the discharge plasma’s application technology. Based on the project of ballast water treatment technology by multiphase nanosecond pulse discharge cooperated with photocatalysis, the nozzles-plate electrode was adopted, system energy and energy efficiency were investigated with different discharge factors and compared when the nozzles were coated with the titanium dioxide (TiO2) film or not. The results show that cooperating with the photocatalysis, pulsed discharge system power and energy efficiency were not significantly affected. Reactor power increases with the absolute value of the input high voltage and pulse repetition frequency and decreases with the distance between the nozzles and the plate. There are no obvious effects of the numbers of the nozzles and the air flow rate. Energy efficiency of the system increases with the absolute value of the input high voltage, firstly, then decreases. It changes inversely with the air flow rate. The energy efficiency of the system decreases with the pulsed repetition rate and the distance between the nozzles-plate. It was up to 25.7% with the input voltage of - 30 kV, and the air flow rate of 80 mL/min, pulse repetition frequency of 50 Hz and 6 nozzles- plate distance of 0.5 cm.
Study on the application of multi-channel isolation power supply in non-equipotential circuits
Authors: Zhao Yuzhuo , Zang Yanchi , Xie Da , Li Xiang , Zhao Bowen
Published: May 2021

In non-equipotential circuits, there is the problem that the switching tubes do not share a common ground. This paper therefore addresses this problem by designing a multi-channel isolation power supply (MCIPS). It mainly includes the square wave generation circuit, the high-frequency transformer and three-terminal stabilized circuit. This paper provides a detailed theoretical analysis of the design and principles of these three circuits. Using Multisim to model a MCIPS simulation circuit and derive the output waveforms of each circuit. The correctness of this solution was ultimately verified. The study of this power supply is of great importance for bridge circuits.
Control Strategy of Plug-in Fuel Cell Hybrid Vehicle Based on Drive Cycle Recognition
Authors: Zhang Yanyi , Hao Dong , Meng Xiangfei , Wang Renguang
Published: May 2021

A control strategy based on drive-cycle recognition is proposed for the energy management control of plug-in fuel cell hybrid vehicle. Firstly, the drive-cycle recognition fuzzy controller was designed and the battery target SOC was adjusted according to the drive-cycle recognition results; Secondly, with the goal of improving the economy of the vehicle and the durability of the fuel cell, the energy management fuzzy controller and the fuel cell switch controller were designed, energy distribution of dual power source was realized combined with the target SOC control result; Finally, the comprehensive drive-cycle condition was established, the drive-cycle recognition strategy was simulated and verified basing on the MATLAB/Simulink simulation platform. The results show that the strategy achieves a reasonable adjustment to the target SOC of the battery, compared with the power following strategy, the hydrogen consumption is reduced by 7.8%, which reduces the occurrences of factors which affect negatively durability of fuel cell.
A new multilevel compensation system for neutral active grounding in distribution grid
Authors: Chen Zhongren , Lu Yipeng , He Yejun , Huang Jian
Published: May 2021

In order to achieve effect of full compensation and zero residual-current, a multilevel compensation system for neutral point active grounding is proposed. The system is composed of three-level compensators. When power grid is grounded, the first level compensates its capacitive current, the second level compensates its active current, and the third level compensates not only its harmonic current, but also the harmonics generated by the former two level compensators, so effect of full compensation is very obvious. When distribution grid is in normal operation, the system uses the asymmetric voltage method to realize accurate detection of capacitive current and active current. In case of single-phase grounded fault, the harmonic current is extracted by fast Fourier algorithm. Then three-level compensators are quickly put into operation for corresponding compensation. A low-voltage simulated power grid is built in the laboratory, and a compensation test is carried out. The test results show that the compensation of capacitive current and harmonic current in grounding fault current is accurate. After further improvement, the system can reach the practical level.
Low frequency vibration test on the loosening performance of bolts for towers of power grids
Authors: Yang Jialun , Xia Lingzhi , Liu Bin , Liu Yaduo , Zhao Bin , Zhang Lichun
Published: May 2021

This paper deals with loosening performance of bolts of transmission towers under low frequency vibration. To evaluate the loosening performance, 30 transverse tests for bolted joint are issued, whose frequency ranges from 1 Hz to 3Hz. The results show that double-nut bolts feature better loosening performance than single-nut bolts, and the loosening performance decreases along with the incensement of vibration frequency.
Effect of Particles on Discharge Characteristics of SF6/N2 Mixed Gas under Power Frequency Voltage
Authors: Pang Xianhai , Wang Xiao , Qiao Songsong , Liu Houfa , Long Yuyou , Xiu Shixin
Published: May 2021

Residual metal particles appear in gas-insulated equipment, which may affect the insulation properties of electrical equipment. In this paper, a specific experimental device is designed to study the discharge characteristics of SF6/N2 mixed gas at different pressures and different mixing ratios under power frequency voltage, and the effect of particle shape, particle material type and gas pressure on the discharge characteristics of SF6/N2 mixed gas. The distortion effect of the shape of the particles and the type of the particulate material on the electric field between the electrodes was simulated. It is found that the breakdown voltage of SF6/N2 mixed gas increases with the increase of gas pressure and SF6 concentration. When the particles are present, the nonlinear effect of metal particles on the breakdown characteristics of SF6/N2 mixed gas in-creases with the increase of gas pressure. Obviously; the more irregular the shape of the particles, the greater the uneven-ness of the corresponding electric field, the greater the breakdown voltage of the SF6/N2 mixed gas; the particulate materi-al also affects the breakdown voltage of the SF6/N2 mixed gas, copper particles and The breakdown voltage of aluminum particles is approximately the same at the same gas pressure, and the influence of iron particles on the breakdown voltage is smaller than that of copper particles and aluminum particles. The research results of the paper have reference value for the study of SF6/N2 mixed gas characteristics and its application in electrical equipment such as GIS.
Study on Measurement Error of Power Frequency Electric Field Intensity Caused by Change of Humidity on Surface Resistance of Field Intensity Meter Supports
Authors: Zhang Kai , Zhou Bin , Yang Lan , Li Yu , Ni Jiang
Published: May 2021

This paper analyzes the different measurement results of field intensity meter in different environments, which confirms that humidity has a great influence on the support parameters of field intensity meter. In addition, by testing the actual electric field, the change of dielectric constant and resistance of field intensity meter and its support under different relative humidity conditions, and comparing the simulation results of COMSOL simulation software, it is concluded that the error of field intensity meter measurement results mainly comes from the influence of humidity on the surface resistance of field intensity meter support, and the relationship between the surface resistance of the support and humidity is obtained.
Fault diagnosis of DC-DC module of V2G charging pile based on Fuzzy Neural Network
Authors: Wang Qunfei , Lu Xiaoli , Yang Dongjunming
Published: May 2021

Aiming at the problem of fault diagnosis of switching devices in DC/DC module of V2G charging pile, a diagnosis method based on fuzzy neural network is proposed. The method combines fuzzy mathematics with neural network, adopts 4-layer forward network and a step degree optimization algorithm, uses the self-learning and self-adaptive ability of neural network, adjusts the parameters of fuzzy set membership function in real-time, and trains a set suitable for V2G charging Fault diagnosis algorithm of DC/DC module of electric pile. Simulation results show that the fault diagnosis algorithm based on fuzzy neural network can effectively diagnose faults.
Development of Helium Direct Current Discharge Ultraviolet Light Source
Authors: Shi Xiaoqian , Zhu Meiqiang , Zhan Zhaokang , Zang Kan , Dong Huajun , Guo Fangzhun
Published: May 2021

Ultra-violet (UV) light source is one of the important components of ultraviolet photoelectron spectroscopy (UPS). A Helium direct current discharge ultraviolet light source is mainly composed of anode, quartz capillary, gas inlet pipe, differential exhaust assembly and heat sink. At 80Pa working pressure and 30mA discharge current, the test sample shows 1nA photoelectron current. Photoelectron current increases proportional with discharge current. The results show that the He DCDUV light source is working well and can be used as the light source in UPS.
Multi-Objective Optimization of the Vuilleumier Heat Pump under Adiabatic Condition
Authors: Xie Yingbai , Zhang Mengtao
Published: May 2021

The Vuilleumier cycle adiabatic model has complex calculations and numerous structural parameters. In order to facilitate the analysis and optimization of the structural parameters of the adiabatic model, a dimensionless method is adopted, a system of dimensionless differential equations containing 7 dimensionless parameters is obtained. Among the 7 dimensionless parameters, 5 dimensionless structural parameters representing the volume structure characteristics of the system are selected as decision variables in the optimization. The non-dominated sorted genetic algorithm-II is used for multi-objective optimization with heating capacity and COP as the target parameters. Finally, the Pareto front was obtained, and the baseline case was optimized using the TOPSIS method. After optimization, the heating capacity and COP increased by 0.701 % and 0.848 %, respectively.
Standard Heat Consumption Modelling Calculation and Operation Optimization of Boiler Steam Temperature System
Authors: Li Fengping , Yuan Jun , Chen Jiayi , Zhang Kailiang
Published: May 2021

The combination of neural network and genetic algorithm not only can improve the operating efficiency and economy of the boiler, but also give the recommended values of the operating parameters. Based on the power plant, the number of hidden layers, nodes and learning rate of the neural network modelling calculation are determined according to the data experiments. Taking the standard heat consumption as the target value, the adjustable and non-adjustable quantities of the input parameters are analysed, the parameters such as the crossover rate, the mutation rate and the GGAP suitable for the research object are selected, and the genetic algorithm is used for optimization. The results show that the standard heat consumptions of all the 100 groups of working conditions are reduced. The average reduction is 153.93 kJ/(kW•h). This indicates that by modelling and optimizing the parameters such as the superheater desuperheating water flow, it can provide operational guidance for actual production.
Research on Heat Dissipation of Diode Laser Array with Sharp-angle Sink
Authors: Zhao Shuyun , Xu Huiwu , Li Dezhen , Yan Lihua , Li Zhaoyi , Li Xianjie
Published: May 2021

The project is designed and analyzed for the heat sink of the semiconductor laser array, and the heat dissipation performance of the heat sink with a sharp-angled channel is simulated by the finite element method. The results show that: compared with the traditional cylindrical cavity, the sharp-angle shape cavity has a stronger heat dissipation capacity. By designing a gradual flow channel inlet and outlet size, the flow channel inlet and outlet two of the large-size and multi-bar array laser are significantly reduced. The chip junction temperature difference at the end makes the array chip wavelength difference controlled within 1.9nm, which effectively improves the absorption uniformity and efficiency of the Nd:YAG crystal in this type of pump module.
Signal Simulation and Test of Cadmium Zinc Telluride Nuclear Radiation Detector
Authors: Chen Yunfei , Zhang Jijun , Wang Linjun , Wang Shulei , Yang Yang
Published: May 2021

In the research and development of nuclear instruments, the simulation and shaping of nuclear pulse signals are very important. Since the output signal of nuclear detectors is very weak and has noise interference, it cannot be processed well by the data acquisition system, so it is necessary to filter and shape the nuclear pulse signals. Using MATLAB 2019a simulation software to superimpose random noise to simulate the output signal of the CdZnTe nuclear radiation detector, the output signal of the preamplifier and the output signal of the main amplifier. The final result is basically the same as the actual signal, which is a simulated nuclear pulse signal, laying the foundation for the nuclear-simulated pulse signal generator.
Design of Single Anti-Reflection Film for High Power Semiconductor Laser Facet
Authors: Xu Huiwu , Li Xianjie , Yan Lihua
Published: May 2021

The catastrophic optical damage (COD) threshold of high power semiconductor laser chip is very important in its application. In this paper, based on the transfer matrix calculation method, a coating model is established to explain the relationship between the design parameters and COD threshold. The influence of the refractive index of the film in the whole range between Air and GaAs medium is analyzed. The influence of the refractive index in the range of 1.1 ~ 3.3 on the reflectivity of the film and on the COD threshold are theoretically simulated. The simulation results show that in the design of actual coating parameters, not only the reasonable PC value, but also the requirement of reducing reflectivity and the trade-off between reflectivity and PC value should be considered. In addition, the possible refractive index parameters of the film, the reflectivity of the corresponding film and the corresponding PC value are reflected in the simulation diagram. This paper provides ideas for the improvement of COD threshold and the reliability of chip facet.
Research and application of cave slag tailings in concrete
Authors: Rao Qi , Zhang Hengchun , Wan Rui , Xi Shuiping , Wu Dianxing , Luo Chunyang
Published: May 2021

This article starts with the characteristics of cave slag tailings, proposes to optimize the quality of the concrete production process and product structure by improving the composition of concrete fine aggregates, and conducts research on the key technologies of the application of cave slag tailings to concrete. Concrete quality and economic cost are the basic frameworks, and the feasibility of using cave slag tailings is comprehensively analyzed. It has been verified by experiments that the application of cave slag tailings can greatly improve the stability of concrete production process, reduce concrete structural defects and quality disputes caused by process control, and can significantly reduce the cost of single main material of concrete and bring good Economic benefits. At present, the slag tailings of the cave have been widely used in the resettlement houses of Houyu, Minhou, the MIXC# building, TA# building and its basement of the fourth phase of Fuzhou China Resources Vientiane City, and all performances have reached the engineering design requirements.
Measurement of CO2 hydrate phase change heat for renewable energy application of biogas
Authors: Li Juan , Xia Xinliang , Liu Changming , Tang Nong
Published: May 2021

Biogas is a renewable clean energy produced by decaying organic matter and its main components are methane and CO2, in which CO2 accounts for 25%~40% (volumetric percentage). The storage and transportation of biogas by hydrate method has attracted wide attention at home and abroad. In this paper, the phase equilibrium conditions for the hydrates in CO2, CO2-THF (tetrahydrofuran) and CO2-cyclopentane systems are researched to determine the phase transition heat of the hydrates of corresponding systems. The results illustrate that the phase transition heat of hydrate is related to the structure formed during experiments. Adding THF and cyclopentane into CO2 hydration system both increases the phase transition heat of hydrate. Phase transition heat of the CO2-THF hydration system increases with the increase of the mass concentration of THF, and the phase transition heat of CO2- cyclopentane hydration system is greater than 200kJ/kg. Results in this paper will be helpful for transportation and utilization of biogas as an renewable clean energy.
Abnormal Detection System Design of Charging Pile Based on Machine Learning
Authors: Li Yanjie , Ji Xiaoyu , Jiang Dongxiao , Meng Tao
Published: May 2021

With the exhaustion of fossil energy and people’s increasing attention to environmental protection, electric vehicles began to be popularized around the world. As an important infrastructure, the EV charging network is faced with the risk of a series of network attacks, which may cause economic losses to the power grid and car owners, and even endanger the stable operation of the power grid. In order to solve the security problem of charging piles, we designed an abnormal detection system for charging piles based on the power consumption side channel and machine learning. By collecting power consumption information of the charging control unit of charging piles, the abnormal detection system determines whether charging piles are facing attacks or not. We have verified three kinds of attacks, proving that our anomaly detection system can effectively detect attacks and protect the security and stable operation of charging piles.
Characterization on microstructure of interface and failure analysis of SiC fiber reinforced Ti-17 composites under tension load
Authors: Zhao Wenxia , Ciuca Octav. , Yang Xiaoguang , Tao Chunhu , Zhou Xiaorong , Liu Changkui
Published: May 2021

In this study, the ultimate tensile strength of unidirectional SiC-fiber/Ti-17 composites was measured in the as-produced condition at room temperature. Fracture and interfacial reaction zone was characterized by using laser confocal microscopy, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy. Elemental distribution maps of the interfacial reaction layer and titanium matrix were quantitatively examined by electron probe micro-analyzer (EPMA). Micromechanical properties of SiC fiber and titanium matrix was inspected by Nano-indentation. The Fracture failure mechanisms was show that the key microstructural parameters which dominate damage initiation, damage growth and fracture behavior of the composites were explained in detail.
Water-based double layer coating transfer aluminum-plated paper material in the application
Authors: Pan Ruru , Yao Pingzhang , Yu Lin , Fang Xiling
Published: May 2021

This paper introduces a new type of moisturizing paper, which makes the material have a stronger moisturizing effect than ordinary transfer paper through the water-based double-layer coating process. At the same time, the paper has a stronger degradation capacity than plastic film paper, more in line with environmental protection requirements. Through the paper printing machine adaptability verification, the paper has easier processing and stronger printing performance. The development and application of this moistening material is a major innovation in the field of moistening packaging materials research.
Simulation Study of Magnetic Shielding to Address Heat Generation in Rollers for Clamping Aluminum Rod Heated by HTS DC Induction Heater
Authors: Hu Lei , Yan Xufeng , Dai Shaotao , Ma Tao
Published: May 2021

The roller is the connect structure between the gripper and main or auxiliary gearbox, which rotates simultaneously with the aluminum billet. When preheating short aluminum billet, a part of the roller is in the air-gap, which will be heated during preheating the aluminum billet, and the increase in the temperature of the roller can affect the gearbox. To address the roller heat, a magnetic shielding method has been proposed. And the effect of the magnetic shielding of the magnetic field in the roller and the air-gap has been analyzed. The weakening effect of the magnetic shielding on the heating power also has been evaluated. At the same time, the electromagnetic force of the magnetic shielding is also been carried out. The results show that the magnetic shielding can effectively reduce the heating power of the roller. Evidently, adding a magnetic shielding around the roller is feasible to alleviate or solve the problem of roller and gripper heat.
The Effects of Different Splitter Blades Number on Characteristics of Miniature Super-Low Specific Speed Centrifugal Pump
Authors: Zhong Wenqing , Zhou Jin , Zhou Shaoping
Published: May 2021

Splitter blades are often used to improve the performance parameters of super-low specific speed centrifugal pumps, while the number of splitter blades is the most important influencing factor of head and efficiency. In order to study the effect of different number of splitter blades between long blades on the external characteristics and internal flow field of centrifugal pumps, the numerical simulation of four impeller models has been carried out by Fluent. The results show that splitter blades can raise head and efficiency of the centrifugal pump, so that the performance curve moves toward large flow rate area. The low speed area on the pressure surface of the long blade reduces with the slip and separation inhibited. When the number of splitter blades increase gradually, the head of the centrifugal pump has not much increase while the efficiency decreases. Most of the medium flow out through the runner on the pressure surface leaving the others blockage due to the backflow and vortexes, resulting in large hydraulic loss.
A new analytical model for the growth rate of dendrite tips
Authors: Ao Xiaohui , Xia Huanxiong , Liu Jianhua , He Qiyang , Lin Shengxiang
Published: May 2021

It’s well known that the driving forces of dendrite growth in metal solidification typically include temperature undercooling, constitutional undercooling, and curvature undercooling, and these undercoolings are usually computed independently by their corresponding local temperature, concentration, and curvature in a model. This paper derived a new formula only depending on the temperature undercooling based on the dynamic equilibrium relationship and the Ivantsov function for computing the growth rate of dendrite tips at the equilibrium state. By taking the derivative of this formula to find the maximum growth rate, an almost constant ratio of the curvature undercooling to the temperature undercooling was found, specifically, the ratio is in the range of 0.507 to 0.524 corresponding to the temperature undercooling of 4 to 10 K. The analytical result was validated by the numerical simulations of the solidification of Inconel 718 alloy with different temperature undercoolings by using a cellular-automata mothed. The numerical results suggested a ratio of 2/3 of the curvature undercooling to the temperature undercooling for the given Inconel 718 alloy.
Experimental Study on the Dimension Error of Bridged Structures Printed by Fused Deposition Modeling
Authors: Yang Chun , Liu Jianhua , Ao Xiaohui , Xia Huanxiong
Published: May 2021

Fused deposition modeling, a popular additive manufacturing technology by extruding thermoplastic materials, can be used to print structural parts with complex geometries. However, when a part appears an overhanging structure, it is usually necessary to add an auxiliary support structure. The added structure not only causes material waste but also secondary damage to the printed part owing to removing the support structure in post-processing. To understand the dimension error of bridged structures without support structures, this paper experimentally investigated the effects of the bridging span, layer thickness, nozzle speed and temperature on the sagging deformation of the bridged structures. The limitation of bridging span and the sensitivities of the printing parameters were found.
Forming Control of Rod-Shaped Tantalum-Tungsten Alloy Explosively Formed Projectile
Authors: Xue Weizhao , Li Mei , Men Jianbing , Jiang Jianwei , Wang Shuyou
Published: May 2021

In order to obtain the charge structure of rod-shaped tantalum-tungsten alloy (Ta-W) explosively formed projectile (EFP) with good performance indicators, the LS-DYNA numerical simulation software was used to study the arc-cone liner different charge structure parameters (such as curvature radius, half cone angle and thickness of liner, charge height and shell thickness) on the forming of Ta-W EFP so that the optimal range of each structural parameter was determined. The primary and secondary order of the influence of various structural parameters on the forming performance of Ta-W EFP was obtained by orthogonal optimization design, and the optimized plan of rod-shaped Ta-W EFP was determined (curvature radius of liner is 1.16071D, half cone angle of liner is 68.5°, thickness of liner is 0.02054D, charge height is 0.85714D and shell thickness is 0.08929D, where D is charge diameter). The results show that the performance indicators of the optimized plan of rod-shaped Ta-W EFP are better, whose velocity is 2312m/s, length-to-diameter ratio is 4.41998, compactness is 0.95929 and necking ratio is 0.21109.
Effect of initial temperature and initial pressure on the lower explosion limit of aviation kerosene
Authors: Ning Yongqian , Zhang Liang , Wang Zhi , Ning Xiaoyao , Wang Jian
Published: May 2021

The effect of initial temperature and initial pressure on lower explosion limit (LEL) of RP-3 aviation kerosene vapor was investigated experimentally. The experiments were conducted in an explosion limit equipment at initial temperature of 40-160 °C and initial pressure 100-160 kPa. In the temperature-pressure range studied, the LEL decreases with the increase of the initial temperature, while increases as the initial pressure increases. A correlation formula established in the present study can predict the experimental data well. A comparison of the temperature dependence and pressure dependence indicates that the LEL of RP-3 aviation kerosene vapor is mainly affected by the initial temperature. This guides people to pay more attention to the aspect of the heat transfer in the fuel tank of aircrafts avoiding the explosion risk caused by high temperature.
Combined oxidative degradation of ammonia and phenol by homogeneous UV/S2O8
2- process
Authors: Yang Yuke , Wen Zhiguo
Published: May 2021

Utilization of UV in peroxydisulfate (S2O8
2-) activation exhibits a potential for removing contaminants in wastewater. In this study, the oxidative degradation of aqueous ammonia (NH3/NH4
+) or/and phenol by UV/S2O8
2- process was investigated, including the kinetic model of ammonia removal, the effect of pH on degradation efficiency and TOC removal, and influence of S2O8
2- concentrations on contaminants removal. The results revealed that the kinetic model of ammonia removal conforms to pseudo-first-order. Strong alkaline conditions and high dosage of S2O8
2- were profited to ammonia degradation, and the removal percent was up to 95.98% (e.g. 50 mM S2O8
2- at pH 12). The near-neutral environment was conducive to phenol removal, and its maximal removal percent was 96.28% in 30 min at pH 8. In the combined oxidation system of ammonia and phenol, the ammonia removal quickly reached 40.90% in 30 min and got its maximum of 55.20% after 8 h, while the phenol degradation had almost no obvious decline. This study enriches our understanding of the oxidation kinetic of ammonia under UV, and provides new insights for combined oxidation of ammonia and phenol.
Microstructure and fatigue properties of TC4 titanium alloy treated by α+β forging process
Authors: Cui Wenbin , Chen Xuan , Cheng Li , Ding Junliang , Wang Changkai , Wang Bohan
Published: May 2021

As aero engine life increases, blade fatigue has become one of the key factors restricting the high reliability and long service life of aero engine. In this paper, TC4 bar was treated by α+β forging process. The microstructure and mechanical properties of the treated material were observed and tested at room temperature, and the three point bending ultrasonic fatigue test was carried out. The results show that the S-N curve of the α+β forging material presents a double platform shape. The high cycle showed surface cleavage mode, the very high cycle showed internal cleavage mode, and the very high cycle cracks originated from the primary phase cleavage plane.
Two synthetic strategies of (S)-3,3′-bis(azidomethyl)-2,2′-bis(methoxymethyl)-1,1′-binaphthalene
Authors: Shi Huizhong , Wu Changzhi , Huang Yan , Fu Muyun , Wang Huizhen , Zhang Yafeng , Sun Xiaoxia
Published: May 2021

Different effective synthetic strategies of chiral intermediate (S)-3,3′-bis(azidomethyl)-2,2′-bis(methoxymethyl)-1,1′-binaphthalene are described from the original material (S)-3,3′-bis(hydroxymethyl)-2,2′-bis(methoxymethyl)-1,1′-binaphol. The 1HNMR and HRMS spectroscopic analyses have been used to confirm the synthesis of (S)-6.
Operation Characteristic Analysis and Parameter Optimization of District Heating Network with Double Heat Sources
Authors: Zhao Junhong , Li Ying , Li Jingyi , Li Zhi
Published: May 2021

The heating system is a practical engineering problem with multi-parameter coupling and multi-constraint restrictions. The use of optimization algorithms has guiding significance for its high efficiency and energy saving. This paper takes the district heating pipe network with dual heat sources as an example to analyze the operation characteristics of the heating pipe network and optimize its parameters. The thermodynamic model of the dual-heat source district heating pipe network is established, and the NSGA-II algorithm is applied to analyze the operating characteristics. By comparing the upper and lower limits of the interval and the interval when the pipe length and pipe diameter are the decision variables, it is believed that to reduce the loss during the operation phase of the system, quantity adjustment should be avoided as much as possible. The water supply temperature is greater than 95°C, the greater the system fluctuation. Through the NSGA-II algorithm, the Pareto front is obtained, and the TOPSIS optimization method is used to finally obtain the best operating parameters of the pipe network with the best closeness.
Application of Container Building in Community Ecological Environment Renewal——Taking Gejiaying Community in Wuhan as an Example
Authors: Wang Yunfei , Lin Nan , Zhang Nan
Published: May 2021

Community micro renewal should conform to the urban texture and respect the conservation of ecological environment. As an important military industrial area in history, Gejiaying community, located in the ancient city of Wuchang and close to the riverside area, is not only rich in human resources and has a long history and culture, but also its spiritual temperament is in line with the rich industrial heritage groups nearby. Therefore, while reshaping its own historical and cultural characteristics, Gejiaying community should also focus on the continuity and transmission of the city’s history and culture. The terminal product, assembling flexible and environment-friendly containers, should be put into the community micro renewal. The machine aesthetics of container building is skillfully used to continue and repair its cultural context in the renewal of the ecological environment of the community, so as to create the ecological and aesthetic symbol belonging to Gejiaying.
Discussion on ecological system management of urban reclaimed water environment-a case study of Xihua Park in Kunming
Authors: Cao YongQiong , Fu XiaoPing , Wang Hua , Wu YuMei , Shi GuangHua
Published: May 2021

Compared with tap water, reclaimed water in urban water environment is more likely to lead to water eutrophication. According to the local water pollution status and the types of pollutants, the physical, chemical and biological ecological methods should be organically combined in the water environment treatment, and a variety of suitable aquatic plants should be selected for reasonable allocation, so as to achieve complementary advantages, pay attention to maintenance and management, and establish a long-term maintenance and management system In order to realize the sustainable ornamental, efficient purification and low-cost maintenance of urban water ecological landscape, it is necessary to build the plant community of urban water ecological environment and strengthen the bio ecological measures.
Research on Cooperative Protection Mechanism of Ecological Environment
Authors: Lin Hongzhen , Xia Lixin
Published: May 2021

This article aims to study the cooperative protection mechanism of the ecological environment. By using the method of literature analysis to understand the history and development of the ecological environment and collaborative protection. By making a comparison between domestic and abroad research environmental, we learn more protection methods. As the environment for human living, the ecological environment is affected by many factors such as population growth, economic growth and capital investment. Under the situation of social diversification, a collaborative protection mechanism mainly led by enterprises. The way of society and enterprises participate in it together has been proposed. In this regard, we believe that citizens should firmly establish the concept of collaborative governance. The government should integrate multiple forces to coordinate and co-administer the protection of the ecological environment. Departments at all levels should jointly improve the collaborative governance mechanism of the ecological environment. Relevant professional departments should improve the facilities for collaborative governance of the ecological environment level.
FT prediction method based on adaptive model of meteorological data
Authors: Pan Wei-Jun , Zhang Hengheng , Liu Tao , Wu Tianyi
Published: May 2021

Due to the various meteorological conditions encountered in the flight process, the uncertainty of FT will change. In order to obtain the FT error, the secondary surveillance radar and aviation weather forecast data are used for analysis. According to the propagation mechanism of uncertainty, an adaptive prediction model of FT uncertainty is established. The input parameters of the adaptive model include Mach number, flight distance, vector wind and temperature. Cluster analysis and linear regression analysis are used to analyze the accuracy of the model. Compared with the static time-of-flight prediction model, the dynamic time-of-flight prediction model can accurately predict the FT even if the weather conditions are very bad. The dynamic time-of-flight prediction model is applied to air traffic management to further test the accuracy of the model. The results show that the adaptive time-of-flight prediction model based on meteorological conditions can accurately predict the arrival time of a flight to a certain waypoint.