bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulse Detonation Engine Performance Analysis
Authors: Xiao Zhiyi , Zheng Longxi , Lu Jie , Tan Wenhao 
Published: February 2023

Abstract
A brief retroversion is conducted on the developments of pulse detonation engines over these decades. Attempts are made to cover performance analysis, nozzle effects, partial filling, and cooperating work. Researchers have spared no effort to establish accurate models to describe the unsteady nature of pulse detonation engines while the accuracy is relatively just as it comes at the price of more or less simplification. Nozzle design would make a great difference to the ultimate performance as numerical simulations have proved nozzle shape, as well as expansion ratio, needs precisely devised. The partial filling has an impact on specific impulses by altering the pressure relaxation process which is testified by numerical simulations and experiments. Component matching brings a challenge to engineering practice due to the comprehensive and complicated co-reaction between every part of the engine. How to reconcile different components remains a fatal issue as many institutes have done amounts of work to demonstrate the feasibility of such a novel propulsion option.
Thermal Performance Analysis of Solar Seawater Desalination System Based on Heat Pump Cycle
Authors: Zhang Xiaoman , Leng Bo 
Published: February 2023

Abstract
Mathematical model of the solar seawater desalination system based on heat pump cycle was established, which was solved by programming with MATLAB language. The system performance was analyzed by changing four variables, including the initial temperature of water tank, drive hot water temperature drop, the mass concentration of LiBr dilute solution and the system startup temperature. The results show that increasing the initial temperature of water tank is conducive to reducing the heat consumption of the auxiliary heat source and increasing the solar energy supply ratio; Increasing drive hot water temperature drop is beneficial to increase the fresh water production, but the heat of the auxiliary heat source required increases, and the solar energy supply ratio decreases; Increasing the mass concentration of LiBr dilute solution will not change the total heat consumption of the system, the heat consumption of auxiliary heat sources and the solar energy supply ratio, but the fresh water production will decrease; Increasing the system startup temperature will increase the heat consumption of the auxiliary heat source, reduce the solar energy supply ratio, and slightly reduce the fresh water production.
Simulation Study on NO and PM Emission Reduction of Engine by Coupled Miller Cycle with Butanol Blending
Authors: Ye Zixiao , Huang Jialiang , Fan Jinyu , Li Pinfang , Zhang Feifei , Lin Hang , Wang Qiwei 
Published: February 2023

Abstract
Trade-off effect of engine emission, that is, NO emission reduction will lead to increase of PM emission. In order to alleviate the contradiction between NO and PM emission, coupling miller cycle with burning butanol was proposed. The simulation model was built by using AVL-FIRE software. The coupling scheme is optimized by changing intake pressure with power performance as constraint condition and emission reduction as evaluation index. Simulation results show that the mixing ratio B30 combined with miller degree M20 scheme matches the intake pressure 0.213MPa well. On a constant power basis, the simultaneous reduction of NO and PM is achieved.
Influence of Nozzle Structure of Oxygen Lance on Impact Dynamic Characteristics of Supersonic Jet
Authors: Jia Hongbin , Liu Xiang , Gui Lin , Han Peng , Liu Kun 
Published: February 2023

Abstract
In order to realize the smelting effect of high oxygen supply intensity in large and medium-sized converters, a new six hole oxygen lance nozzle with double angle, double flow and staggered double structure is designed in this paper, and the jet characteristics are compared with those of the traditional structure oxygen lance. According to the theory of fluid dynamics and the principle of similarity, the velocity attenuation of the centerline of the jet and the longitudinal section of the oxygen jet are tested by using the oxygen gun jet detection experimental system. The results show that the jet performance of the staggered double structure six hole oxygen lance nozzle is better than that of the traditional structure oxygen lance nozzle. When the ratio of large hole flow is 55%-65%, the angle of large hole is 12°-14°and the angle of small hole is 16°-18°, the ratio of hole flow plays a leading role in the size of jet velocity. The greater the flow distribution, the greater the jet velocity. Using staggered double structure six hole oxygen lance can improve the stirring force of the jet to the molten pool.
Simulation of Sequential Turbocharging Switching Control System for Low Speed Diesel Engines
Authors: Han Yuliang , Yang Chuanlei , Wang Hechun , Wang Yinyan , Hu Deng , Wang Binbin , Duan Baoying 
Published: February 2023

Abstract
In order to study the sequential turbocharging switching process of low-speed diesel engine, this paper uses GT-power software to establish a simulation model of sequential turbocharging low-speed diesel engine. It is enhanced and improved into a model of a sequential supercharged diesel engine. Modules such as load, governor, valve control, and surge margin are set up in the simulation model. Then parameters such as switching speed, valve opening time and response time are set in the model. Through the above preparations, the thesis has carried out the simulation calculation of the sequential supercharging transient switching process and verified the rationality of the setting parameters and the accuracy of the module setting. This provides a certain reference for the valve control strategy of the sequential supercharging switching system of low-speed diesel engines.
Study of Flow Field Characteristics During the Impact of a High-pressure Gas Jet on a Bulk-loaded Liquid
Authors: Wang Jian , Jiang Kun , Cheng Shenshen , Wang Hao 
Published: February 2023

Abstract
A visual experiment platform for high-pressure gas jet impacting the bulk-loaded liquid was designed and built in order to investigate the real law of the interaction between the high-pressure gas jet and the liquid medium during the liquid-balance launch of rocket launcher. The experiments of single-phase gas jet injection and the high-pressure gas jet at different temperatures impacting the bulk-loaded liquid were carried out, and the effects of gas temperature on the characteristics of the gas-liquid flow field have been revealed. The results show that the turbulent mixing between the high-pressure gas jet and the liquid medium leads to the appearance of pressure fluctuations in the gas chamber connected to the nozzle. The higher the gas temperature, the greater the amplitude of the pressure fluctuations. Under the impact of high-pressure gas jet, a gas cavity with an arc-shaped head is formed inside the bulk-loaded liquid. The higher the gas temperature, the faster and more unstable the development of the gas cavity and the flow field. The displacement equation of the gas cavity confirms to the first-order exponential decay function, and the error between the fitting value of the established mathematical model and the measured value is within 2%.
Research and Application of Automatic Crude Oil Metering System
Authors: Zhang Liwen , Yang Xiliang , Li Genchen , Zhang Xing , Qiu Rupei 
Published: February 2023

Abstract
At present, China’s crude oil metering still adopts manual reading (temperature, pressure and flow), manual compensation and correction methods. The workload is heavy, and the calculation results are easy to make mistakes and difficult to manage. In order to change this situation, this paper studies and proposes an automatic compensation calculation method for crude oil metering, and develops an automatic metering and management system for crude oil. The system has the functions of automatic collection and storage of on-site data (temperature, pressure and flow), offline metering, online metering, real-time monitoring of metering process flow, query and analysis of historical data, etc., which greatly reduces the workload of workers. At the same time, through the analysis of the system uncertainty and the comparative analysis of the field experimental data, the accuracy of the automatic metering system is verified, which provides a theoretical support for the system parameter selection and operation.
Research on the Anti-Disturbance Performance of Concrete
Authors: Wang Yuan , Zheng Xinxin , Zhang Jinhong , He Rui , Wang Ke 
Published: February 2023

AbstractIn order to speed up the construction progress of the project, the pouring of concrete is often carried out at the same time as blasting and excavation, resulting in various vibration interference to the concrete. These vibrations damage the performance and service time of the concrete. Therefore, it is especially important to study the anti-disturbance performance of concrete. By analyzing the research results of domestic and foreign, the influence law of disturbance on concrete was summarized and its action mechanism was discussed. The evaluation methods and improvement measures for the anti-disturbance performance of concrete were summarized. In addition, the deficiencies in the previous studies were pointed out in this paper.
Study of PLA-based Wood-Plastic Composites
Authors: Li Xiangrui , Yu Jiaming , Meng Lingyu , Li Chunfeng , Liu Mingli , Meng Lipeng 
Published: February 2023

Abstract
In order to cope with the environmental problems of plastic pollution and greenhouse gas emission, the development and utilization of environmentally friendly materials is urgent. Polylactic acid (PLA) is a completely degradable thermoplastic aliphatic polyester, but the high cost and poor toughness of PLA limit its wide application. PLA-based wood-plastic composites (WPC), prepared by laminating PLA with wood fibers, can reduce production costs and compensate for the deficiencies of PLA mechanical properties, while still retaining biodegradability. The synthesis of PLA, the preparation of PLA-based WPC, and the performance enhancement achieved by different wood fibers prepared WPC are presented. It is hoped that this will provide guidance for the early promotion of PLA-based WPCs.
Study of ZrO2 Content on Hardness and Wear Characteristic of Coatings
Authors: Feng Pei , Shi Yuhua , Shang Peng , Peng Tongtong , Feng Rongrong , Li Bin , Zhao Xinsheng 
Published: February 2023

Abstract
Aluminum alloy has limited its application due to low hardness and poor wear resistance. Therefore, surface modification by electroplating is beneficial to improving hardness and wear resistance properties. Hence, Ni/W–ZrO2 coating was organized on aluminum alloy by electro-deposition method in this paper. The optimum organization parameters were obtained. The impact of different ZrO2 additions on the hardness and friction wear properties of Ni/W–ZrO2 coatings were further investigated. The SEM, Vickers examiner and wear examination are used to analyze the micromorphology, micro-hardness as well as friction and wear resistance properties, respectively. The results show that when the addition of ZrO2 was 40g/L in the deposition bath, the Ni/W–ZrO2 coating possesses the optimum micro-hardness of 384HV. This is mainly attribute to the dispersion-enhancing effect of ceramic particles. This work offers a new approach to surface strengthening technology for aluminum alloys.
Characterization and Imaging of Damage during Creep Crack Growth in 2219 Aluminum Alloy
Authors: Guo Qi , Guo Zhimin , Fu Kang , Cao Yuling , Geng Xihui , Wang Xi , Tang Shengming 
Published: February 2023

Abstract
Aluminum alloys have been extensively applied in aerospace field due to their light weight. Some research results show that creep crack growth is one of the main reasons for the failure of aluminum alloys in high temperature service environment. Micro-CT is a novel method to obtain damage information inside materials, which can quantitatively characterize the volume, quantity and distribution of damage. In this paper, the characterization method based on X-ray micro-CT is utilized to study the growth behavior of damage during creep crack growth of 2219 aluminum alloy. The results indicate that the growth of creep cracks requires the existence of small-volume of damages at the crack tip. And creep crack growth rate in the centre of the sample is greater than that on the surface. The existence of large-volume independent branch cracks creates conditions for the unstable propagation of creep cracks. When the crack grows locally, it does not follow the direction vertical to the stress, but preferentially connects with the surrounding damage. Whereas, the creep crack growth will eventually return to the direction perpendicular to the stress under the influence of stress.
Improving the Radon Adsorption Capacity of Activated Carbon by Liquid Nitrogen Modification
Authors: Yu Bo , Deng Xiangyuan , Wu Haibiao , Yue Chengtao , Xiao Detao 
Published: February 2023

Abstract
Radon is a naturally occurring radioactive inert gas that poses a significant threat to the human health. Coconut shell activated carbon has been verified to be the best radon adsorbing material, but its radon adsorption capacity still cannot meet the requirement of industrial applications. Activated carbon modification using liquid nitrogen is an effective method for improving the radon adsorption capacity, but it is necessary to determine the conditions for large-scale production. In this study, the influence of environmental temperature, container geometry, and amount of activated carbon and liquid nitrogen on the modification effect are examined. The results show that the activated carbon has the best modification effect when the container is placed in a water bath at 50 °C. The container geometry and activated carbon mass have a minor influence on the modification effect. Further, the radon adsorption capacity is increased by 36% when 6.5 L of liquid nitrogen is added to 1 kg of activated carbon. The characterization results reveal that the chemical structure and elemental content of the activated carbon do not change after modification, but the number of micropores is significantly increased, especially the micropores with a size of 0.5-0.6 nm, which is related to the radon adsorption capacity of the modified activated carbon. Overall, the liquid-nitrogen-based modification is a simple, environment-friendly, and low-cost method to improve the radon adsorption capacity of activated carbon, which can be used in the large-scale production of highly efficient radon adsorbents.
Civil Aircraft Conceptual Design for CO2 and NOx Emission Reduction
Authors: Mu Tengfei , Tao Li 
Published: February 2023

Abstract
With the rapid development of the air transport industry and the continuous increase of fuel consumption, the environmental problems caused by the emission of civil aircraft have been paid more attention by public. In the future, the aircraft with global market competitiveness should not only meet the indicators of economy and reliability, but also consider the requirements of environmental protection, especially the negative impact of CO2 and NOX emissions. In this research, an assessment model of aircraft emissions is established to calculate the impact of CO2 and NOX emissions on global temperature changes. Further, an optimization framework for aircraft conceptual design is established combined with the analysis models of traditional disciplines such as aerodynamics and cost. Then, aiming at the low emission of the aircraft under the condition of satisfying the performance constraints, objective optimization design studies are conduct, and the design parameter could be valuable reference for the aircraft preliminary design.
Application of Conical Surface Brakes in Cranes
Authors: Wang Songlei , Liu Fang , Jin Hui 
Published: February 2023

Abstract
Both drum brakes and disc brakes have their own structural limitations and advantages. As a new type of industrial brake, cone brake combines the advantages of electric hydraulic drum brake and electric hydraulic disc brake, makes up for the shortcomings of drum brake and disc brake, and greatly improves the service performance and safety performance of the brake. This paper introduces the structure composition and working principle of the conical surface brake, analyzes the advantages of the conical surface brake through the comparison with the drum brake, carries out experimental research, analyzes the test results, gives optimization suggestions for the existing shortcomings, and explores the application prospect of the new brake combined with the introduction of application examples. This paper provides a reference for the technical innovation of brake and a new choice for brake users.
Optimization Application of Deep Belief Network in Gear Fault Diagnosis
Authors: Liu Haotao , Wang Jingjing 
Published: February 2023

Abstract
Deep belief networks (DBNs) in the process of the application of the gear vibration signal fault diagnosis, vector network depth, the number of neurons in hidden layer, set the initial parameters, such as there is a certain blindness, and for different data sets, the influence of initial parameters is different also, in order to get ideal fault recognition rate, the initial parameters have to be repeatedly debugging, This process is not only time-consuming and laborious, but also disadvantageous to its universal application in fault diagnosis. To solve this problem, this paper mainly optimizes the number of hidden layer neurons and learning rate of DBNs. The diagnosis example shows that after optimization, the initial parameter setting is more accurate and efficient, and the fault identification rate is significantly improved.
Design of High-Precision Micro-Capacitance Detection System
Authors: Kang Jianbing , Li Jing , Liu Xuefeng , Lian Huadong , Zhang Ai 
Published: February 2023

Abstract
The focus of this paper is on the development of micro-displacement measurement system of Beam Steering Mechanism (BSM) and Fast Sweeping Mirror (FSM) using in space remote sensor. The main objective is to design a micro-capacitance measuring technology based on Pcap01. In the proposed approach, first, the principle of capacitance measurement and the design of hardware and software of the system are introduced; then, the system is implemented to high-precision results below 3.5nF. The experiment results show that under the 1KHz output data rate, the system can achieve a resolution of 1.4fF in the range of 1pF~30pF, which can meet the system requirements of range and accuracy ratio of 20000.
Evaluation of Electromechanical Transmission System at Vehicle Level
Authors: Xu Baorong , Wan Li , Wu Haoyang , Liu Cheng 
Published: February 2023

Abstract
With the rapid development and maturity of new energy technologies, electromechanical transmission systems, which deeply integrate electric transmission and mechanical transmission technologies, have been widely used in various vehicles and equipment. To ensure high efficiency and reliability of electromechanical transmission systems, this study investigated the vehicle-level comprehensive performance evaluation index system for an electromechanical transmission while focusing on the electrical properties of the transmission system. An evaluation index was constructed for the vehicle-level electromechanical transmission system. An expert investigation method was used to select and optimize the evaluation indicators, and the evaluation index system for the electromechanical transmission system was obtained. Based on an analytic hierarchy process and the grey relational algorithm, a vehicle-level evaluation method was established for the electromechanical transmission system. This study provides a theoretical basis and guidance for the validation, development, and design finalization of electromechanical hybrid vehicles.
Simulation Analysis of Personnel Evacuation Environment in Fire at Subway Platform with Different Suspended Ceiling Forms
Authors: Zhu Changlin , Li Fuyuan , Li Xiaqing , Zhang Rongguo 
Published: February 2023

Abstract
Taking the island platform layer of a subway station in Xi’an as the research object, the dynamic simulation sortware FDS is used to constructs the physical model of the platform layer with three different suspended ceiling forms (flat, square concave and grille). Under the condition of 5 MW fire source intensity at the platform layer, The parameters related to the personnel evacuation environment, such as the smoke spreading process, the temperature distribution of the ceiling layer, the temperature distribution at human eye characteristic height layer, the CO concentration distribution and the wind speed at the stairway, were simulated under each model, and the smoke emission effect under three different ceiling forms was compared and analyzed when the platform layer in the subway station was in fire. The results show that the square concave ceiling form can effectively slow down the flue gas spreading process and reduce the flue gas concentration outside the stairway, but it will cause local fluctuation of temperature and CO concentration distribution. The grille ceiling form can enhance the height of the smoke layer and make the evacuation in a safer environment before and during the middle stage of the fire, but too high smoke layer is not conducive to smoke exhaust.
Numerical Analysis and Experimental Study on Impact Reduction of Flexible Bag Damper for Honeycomb Core Exposed Platform
Authors: Xiao Wangqiang , Huang Zijie , Qin Kai , Ouyang Han 
Published: February 2023

Abstract
The exposure platform is a component used to carry adapter, initiating explosive device and other important instruments in aerospace engineering. When the initiating explosive device on the platform does work, the initiating explosive shock produced by the initiating explosive device on the platform poses a great threat to the precision instruments carried on the platform. This high-frequency transient and high-level initiating explosive shock wave is easy to cause damage and fragmentation of various precision instruments on the platform, Therefore, it is of great significance to reduce the impact of initiating explosive environment on the exposed platform in the aerospace field. In this paper, a flexible bag damper is installed on the honeycomb core exposed platform to study its dynamic characteristics, and to explore the impact reduction effect of the flexible bag damper on the exposed platform; The discrete element method is used to simulate and analyze the flexible bag damper system to obtain the optimal damper parameters, and then the experiment is carried out to verify its effectiveness.
A Pose Resolution Analysis Method for a Stewart Parallel Robot
Authors: Liang Fengchao , Tan Shuang , Zhao Xiaolin , Fan Jiankai , Zhe Lin , Shi Zhicheng , Kang Xiaojun 
Published: February 2023

Abstract
In order to develop a high-resolution 6-DOF parallel robot, a method for analysing parallel robot’s position and orientation resolution is proposed, which is based on the same scale scaling and quantifying of struts increment. Firstly, calculating struts increment of the target position and orientation. Secondly, reducing struts increment in the same proportion. Thirdly, quantifying them with the resolution of the strut, and the minimum struts increment and struts length are obtained. Lastly, six single DOF minimum motion increments, namely pose resolution, are obtained after forward kinematic solution. The analysis software is compiled with VC++, and the 6-DOF Stewart parallel robot for the secondary mirror of a high-resolution space camera is designed. The measured results show that the analysis results of pose resolution are basically consistent with the measured values, and the analysis method has strong engineering guiding value.