bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tube-burst Analysis of SA-213TP437H high Temperature Superheater
Authors: Tan Xiaoxia 
Published: January 2022

Abstract
A SA-213TP437H high temperature superheater tube burst in a power plant. In this paper, combined with it’s runtime environment, macro examination, metallographic examination, electron microscope observation and micro area composition analysis were used to analyze the failure reason of the sample tube. The results show that: Due to the fine grain size of superheater tube, a large number of σ brittle phase are precipitated in the metallographic structure in lower temperature. During long-term running, the tube was affected form low cycle fatigue cracking by temperature stress coursed by the load change of generator set, start and stop and so on., which is a long-term over temperature tube burst. Although it is an example of misuse of ultra-fine grain steel pipe, it is recommend that the power plants should conduct spot-check of grain size for other SA-213TP437H high temperature superheater tube, and eliminate similar dangers of superheater tube burst.
Effects of Raceway Convexity on Friction Moment of Tapered Roller Bearings
Authors: Liu Lei , Liu Wentao , Wang Kejun , Wang Dongfeng , Wang Yanjun , Zhang Xu 
Published: January 2022

Abstract
The Effects of raceway convexities on friction moment of tapered roller bearings were studied in this paper. A new theoretical model of friction torque of tapered roller bearings was established considering the roughness and convexities of inner and outer ring raceways. Friction between roller and raceways were analyzed under the condition of elastohydrodynamic lubrication. Based on the theoretical model and experiments, the changes of friction torque with respected to raceway convexities of tapered roller bearings were obtained. The results show that the friction moment decreases with the increase of raceway convexities, while the increase of raceway convexity leads to the increase of contact stress. Therefore, the convexity values should be balanced between friction torque and contact stress. The convexity values should be balanced between friction torque and contact stress. The optimum values of the bearing being measured raceway convexities should be 5 ~ 6μm under the test conditions.
Study on Sound Radiation Characteristics and Sound Insulation of Extruded Aluminium Plate
Authors: Wu Yanan , Li Li , Zhang Yunfei 
Published: January 2022

Abstract
The use of extruded aluminium plates in the subway car body can reduce the weight of the car body, but it will bring about the negative result of increased noise in the car. The extruded aluminium panels belong to rib-stiffened plate structure in which both local short wave deformation and whole long wave deformation coexist. Studying the vibro-acoustic characteristics of this structure helps to effectively control the noise in the car. In this paper, Acoustic model of extruded aluminium plate and equivalent plate were both built up based on the hybrid method of finite element and statistical energy analysis(FE-SEA) and the statistical energy method (SEA) respectively. According to the theory of statistical energy analysis(SEA), the equivalent modelling method of the aluminium extrusion was presented using a single plate This paper focuses on the sound radiation characteristics and sound insulation of extrude and equivalent structures. Results show that no matter what method is used, the calculation of the sound power and sound insulation of the two structures has the same trend. However, the results of the FE-SEA method can capture the natural frequency of the board and be more accurate reflect vibro-acoustic characteristics of extruded aluminium panels in the middle and low frequency. Equivalent plate can well predict the sound radiation characteristics and sound insulation in the mid and high frequency by using the SEA parameters of the aluminium extrusion.
Study on the high temperature microstructure stability of the high Al content Ni-based single crystal superalloy
Authors: Teng Junpeng , Su Yan , Zhong Yong , Luo Laizheng 
Published: January 2022

Abstract
The high-temperature structure stability of high Al content Ni-based single crystal superalloy was studied, the microstructure was observed, and the micro-mechanism of the thermal stability of the material was analyzed. The results show that the exposure time and exposure temperature have significant effects on the stability of the alloy’s high-temperature structure. With the increase of exposure temperature and/or exposure time, the γ’ phase in the material becomes coarser, gradually connects and grows, and the stability of the material structure is obviously reduced. Compared with standard heat-treated alloys after high temperature exposure, The absolute value of the γ’ and γ phases misfit increases significantly. With the increase of exposure time, although the absolute value of the two-phase misfit continues to increase, the increase of its absolute value gradually slows down. The long-term structural stability of the alloy under continuous exposure to high temperature environment is good.
Cause analysis on tube brust of T23 steel water-wall in a ultra-supercritical unit
Authors: Xu Yang , Chen Le , Wang Song 
Published: January 2022

Abstract
During the hydrostatic test of an ultra supercritical unit, the water wall burst occurred. The causes of leakage were analyzed by means of macro observation, chemical composition analysis, metallographic examination and hardness test. The results show that the formation of cracks is related to fatigue, extending from the inner wall to the outer wall, accompanied by corrosion and oxidation. Fatigue is the main cause of transverse crack formation.
Research on liquid flow behavior in deformed microfluidic channels made of PDMS material
Authors: Zhang Min , Luo Jianguo , Hu Rui , Lu Wenjie 
Published: January 2022

Abstract
In order to improve the application performances of current microfluidic systems, the liquid flow behavior in deformed microfluidic channels made of PDMS material is deeply researched in this study. During the flowing process, liquid pressure features in inelastic and elastic channels are tested and compared respectively, serious channel deformation in elastic PDMS channels is found, and the key influencing factors are summarized and provided, including channel aspect ratio α, top membrane thickness th and channel width w, etc. This study reveals the liquid flow behavior in microfluidic systems made of PDMS material, and provides theoretical and experimental basis for further structural optimization of the systems.
Effect of Ce on Microstructure and Mechanical Properties of AZ91 Magnesium Alloy
Authors: Feng Zhengyang , Wang Enmin , Zhang Mingyu , Li Xuemeng , Su Chunjian 
Published: January 2022

Abstract
In this paper, gravity casting experiments were used to prepare AZ91-xCe alloys, and the effects of Ce addition on the mechanical properties and structure of the AZ91-xCe alloy were analyzed. X-ray diffractometry and metallurgical microscopy were used to characterize the phase composition and microstructure of the experimental alloy, and the strength and hardness of the alloy were tested and analyzed. Results show that the addition of a small amount of Ce generates a high melting point, thermally stable A14Ce, and reduces the porosity of the alloy. The tensile strength and yield strength of the AZ91-xCe alloy have been significantly improved under joint strengthening of multiple mechanisms of fine-grain strengthening, precipitation strengthening, and solid solution strengthening. By comparing and observing the mechanical properties and microstructures of alloys with different Ce concentrations, it was concluded that at a Ce content of 0.5%, the overall performance of the alloy is optimal. Compared to the AZ91 alloy, the tensile strength was increased by 29% and the yield strength was increased by 34%.
Reduction of thermal resistance of Ag-coated GFs/copper structure using nano-Ag paste as interconnection
Authors: Lv Zhen , Zhou Chenfei , Liu Johan , Lu Xiuzhen 
Published: January 2022

Abstract
Reduction of the thermal resistance between graphene films (GFs) and substrate is crucial to the application of GFs in thermal management. GFs/copper structures were prepared using nano-Ag paste as interconnection material. The effect of the thickness of nano-Ag paste on thermal resistance of GFs/copper structure was investigated. A thin layer of Ag was coated on GFs by physical vapor deposition (PVD) to further reduce thermal resistance. The thermal resistance of GFs/copper structure using Ag-coated GFs is 5.84% lower than that using raw GFs. The thermal resistance of GFs/copper structure decreases first and then increases with the increase of coating temperature and thickness of Ag layer. The minimum thermal resistance of 1.64 mm2·K·W−1 was gained for GFs/copper structure using GFs coated Ag at 300 °C for 60 min.
The influence of pre-plating on the LME phenomenon of advanced high strength steel
Authors: Bai Xue , Han Yun , Jiang Guangrui , Liu Huasai , Zhang Yongqiang 
Published: January 2022

Abstract
The galvanized steel plate is developed to protect the car from corrosion. During the resistance spot welding, the liquid metal embrittlement (LME) phenomenon occurs because of the lower melting temperature of zinc, then the melted Zn would get penetrating into the austenite grain boundaries which would cause the LME embrittlement. The high-temperature three-point tests at 600°C, 1 mm/min could be used as experimental simulation procedure. The pre-plating technology has been used to improve the LME resistance property of the galvanized steel. It could be found from the microstructure analysis that the pre-plating Ni technology could partly solve LME issue.
Effect of compression loading speeds on the room temperature mechanical properties of as-extruded AZ31 magnesium alloy
Authors: Chen Yu , Cao Fenghong , Deng Chi , Zhang Yong , Jiang Minggang , Xiong Zubin , Shi Fulong , Liu Ruocen , Fan Kai , Wang Feng , Li Ming , Cao Hao , Gong Yusen , Chen Ruzhi 
Published: January 2022

Abstract
The room temperature compression experiments of as-extruded AZ31 magnesium alloy under different loading speeds were carried out on a universal tensile testing machine. The fracture failure characteristics and mechanism of the alloy under different compression loading speeds were analyzed by scanning electron microscope (SEM) and optical microscope (OM). The results show that during the compression test, the crushed AZ31 magnesium alloy sample has a certain pier coarseness, the macro fracture of the sample is located at one third of the sample, and the macro fracture mode is 45° shear fracture with the sample axis; With the increase of loading speed, the coincidence degree of macro fracture becomes worse, and its compressive strength changes in an undulating manner. When the loading speed is 2mm/min, the compressive strength reaches the peak value of 413MPa, and the fracture morphology of the sample shows a typical flat and flat rock like ductile brittle mixed fracture. With the increase of loading speed, the proportion of brittle fracture components increases, the shape of shrinkage fracture is rock like fracture, and the fracture fluctuation is relatively slow, the dimples distributed on the fracture surface are elongated and torn, and the compression speed has no obvious effect on the fracture morphology.
Preparation of Polymer Microemulsion Flocculant and its Application in Drilling Fluid
Authors: Wang Xue , Xu Nan , Zhou Kuisan 
Published: January 2022

Abstract
Organic macromolecular flocculants have broad application prospects in drilling fluid systems due to their strong adsorption capacity and many other advantages. At present, polyacrylamide polymer is mostly used in drilling fluid, which is difficult to dissolve, time-consuming and laborious. In this regard, this study uses acrylamide and acrylic acid as monomers, mixes acrylic acid with potassium hydroxide, adds disodium ethylenediaminetetraacetic acid solution after adsorption and filtration, and then adds acrylamide to prepare a mixed solution, using H2O2 as the initiator, polymerization reaction in microemulsion to prepare macromolecular microemulsion flocculant. It can be quickly dissolved by adding a small amount of film release agent OP-10 during application. Through the laboratory evaluation experiment of drilling fluid, it has stronger flocculation inhibition effect on the slurry formation and drill cuttings. It has strong ability to contain drill cuttings and anti-drill cuttings pollution. It is easy to absorb water to expand and can be dispersed and collapsed. The drilling roller recovery rate is high. The field application was good when carried out in Shunbei 5-14H.
Analysis and research on fracture cause of connecting bolt of wind turbine spindle
Authors: Yun Feng , Liu Jun , Liu Chunyu , Zhao Xiaochun 
Published: January 2022

Abstract
On a certain day in 2018, the main shaft connecting bolt of a wind turbine in a wind farm broke and failed during operation. In order to find out the cause of fracture, the fractured spindle connecting bolt was comprehensively detected and analyzed by means of appearance state analysis, chemical element composition analysis, mechanical property detection analysis, microstructure detection and fracture micro area analysis. The results show that the main reason for the fracture of the main shaft connecting bolt is that the hydrogen penetrates into the bolt surface due to improper process control during the production process, resulting in hydrogen embrittlement in the local area of the thread root. Thus, during the operation of the fan, under the combined action of bending, shear and tensile stress, the connecting bolt of the main shaft cracks at the bottom of the first thread on the side of the self rigid rod with the most concentrated stress, and expands in the form of “herringbone” brittle fracture until the overall fracture failure. It is recommended to check the bolts in the same batch to prevent hydrogen embrittlement in the whole batch.
Methodology for optimization of preload in a bolted-flange connection based on Markov theory
Authors: Wang Yuezhen , Liu Zhifeng , Li Ying , Yang Congbin 
Published: January 2022

Abstract
The bolted-flange connection is one of the most popular detachable mechanical joints in mechanical flange connection. It is well known that bolted-flange joints need to be tightened to meet the assembly performance in practical engineering applications. However, the dispersion of the pre-tightening force caused by the elastic interaction between the bolts has a serious impact on the sealing and safety of the product, and therefore the optimization of bolt preload has always been a hot spot in the assembly research field. Combining mathematical theory and experimental data, this paper proposes an optimization model for uniformly distributed preload based on the Markov theory. The torque method was utilized to fasten the bolt-flange joint. The bolt pre-tightening force in the final state was collected and used as sample data. A state transition model was constructed to determine the state transition matrix. Ultimately, an iterative model of the preload was deduced, and the rationality of the model was verified through experimentation. The proposed optimization method of bolt preload can be applied to determine the initial preload of each bolt. This method improves the assembly efficiency and accuracy, which provides a theoretical approach to effectively guide the tightening work of bolted-flange connections.
Simulation calculation of temperature field of gearbox in straddle monorail train
Authors: Xue Hao , Xu Honghai 
Published: January 2022

Abstract
For a straddle-type monorail train gearbox, analyze the heating mechanism and heat transfer mode of each element in the gearbox, establish a heat transfer model of the gearbox, use empirical formula to calculate the heating power of each heating element, and use the flow field analysis to monitor it. Accurately calculate the convective heat transfer coefficient for the volume fraction of oil and gas in each cavity. Using the method of finite element simulation, the influence of different oil injection and large spiral bevel gear steering on the temperature field distribution of the gearbox is calculated and analyzed. The results show that when the large spiral bevel gear turns for a certain amount of time, the maximum temperature of each part of the gearbox at high oil level is higher than that at low oil level; When the amount of oil injection is constant, the temperature of each part in the reverse rotation of the large spiral bevel gear is higher than that in the forward rotation. This article provides the main reference for the prediction of the temperature field of the gearbox of the straddle monorail train and the improved design of the lubricating oil passage in the gearbox.
Mathematical modelling and simulation machining of CNC milling of double-arc spiral internal bevel gear with nutation drive
Authors: Xie Daizhi , Yao Ligang , Wang Zhenya , Li Gaosong 
Published: January 2022

Abstract
The machining method of double-arc spiral internal bevel gear with nutation drive-by milling cutter was proposed in this paper. The mathematical modelling of milling cutter trajectory and axial cut-off of forming milling cutter was established, the special machining tool model of bevel gear was further developed by Solidcam, the simulation machining of bevel gear was carried out. Then, the gear model obtained after simulation was compared and analyzed with the theoretical gear model, and the ideal experimental results, confirmed the CNC modelling milling method processing technology could be used to process bevel gears, the research is very important to improve the development of nutation dynamic transmission.
Research on simulating the movement track of consumers holding cigarettes by using manipulator
Authors: Wang Hao , Zhang Ying , Wang Xu , Yu Zhenhua , Zhan Jianbo , Wang Tao , Zheng Han , Yue Baoshan , Yu Tingting , Xie Jiao , Yu Jiang 
Published: January 2022

Abstract
Consumers’ different smoking habits and movement trajectories in the process of smoking have an important impact on cigarette combustion quality and consumption feeling. By analysing the typical action of holding a cigarette, the position, posture and spatial trajectory of the cigarette were described, and the position and posture of the end effector at the beginning and end of the smoking process were considered. The curve function connecting two endpoints can be selected according to the actual constraints. There are 6 degrees of freedom in space of cigarettes, therefore, in order to simulate the motion trajectory of consumers holding cigarettes, 6R industrial robot can realize the motion trajectory of cigarettes in space. The cigarette is clamped by the cigarette holder installed on the flange at the end of the robot, and the robot drives the cigarette holder to complete the movement track of the cigarette.
Multi-objective Green Flexible Workshop Scheduling Considering Multi-energy Consumption Factors
Authors: Gao Shang , Liu Chang , Wang Guan 
Published: January 2022

Abstract
In order to solve the energy consumption problem of shop floor caused by machine processing, adjustment, idling and workpiece transportation, the green flexible workshop scheduling problem was studied, and a multi-objective optimization model was established with the maximum completion time, total machine load and total energy consumption as the objectives. The double-layer coding strategy was adopted to encode processes and machines respectively to optimize the scheduling scheme, and then the adaptive hybrid crossover scheme, mutation scheme and improved elite retention strategy were adopted to improve the operation efficiency and population diversity of NSGA-II algorithm. Finally, a case study is used to verify the effectiveness of the algorithm in solving the multi-objective green flexible workshop scheduling problem, which provides a reference for enterprises to achieve green manufacturing.
Innovative Analysis and Application on Magnetograms Signal
Authors: Wang Yantong , Zhou Lingyi 
Published: January 2022

Abstract
This study aims to make research on magnetocardiography (magnetograms) signals. Magnetocardiogram is a non-invasive method to record and analyze the magnetic components of the electromagnetic field generated by cardiac electrical activity in the cardiac cycle. We conclude the basic characteristics of the magnetograms signal to summarize the existing magnetograms measurement principles. Then we combine the initial development process and detection means of magnetograms by discussing the signal shielding of magnetograms from two aspects of hardware and software. We compare several methods of shielding electromagnetic signals on hardware and finally obtain an excellent means to shield external signals at this stage. We also conclude the current application of magnetograms in medical treatment.
Simulation study on photon generation and collection of tower applied to NICA-MPD electromagnetic calorimeter
Authors: Peng X. , Zhu K. , Ji X. , Xiao M. , Luo F. , Huang Y. , Zhu J. , Xiao W. , Luo S. , Liu Y. , He L. , Wang X. 
Published: January 2022

Abstract
Shashlik tower, which is composed of absorbers and
scintillators alternately, surrounded by reflector and coupled with
Silicon Photomultiplier (SiPM) by Wavelength-Shifting (WLS) fibers,
is a significant component to measure the energy and position of
photons and electrons in Electromagnetic Calorimeter (ECal), a key
detector of the Multi Purpose Detector (MPD) at the Nuclotron-based
Ion Collider facility (NICA) in Russia. In this paper, the effect of
materials adopted for absorber, reflector and WLS fiber, the length
and curvature of fibers and the electrons incident position on
photons transmission performance of tower is simulated based on
GEANT4 software. The impact of Gaussian deviation's electron beam
energy and spread of 10% in the energy range on the energy
resolution of tower is also studied. Results show that the low
polishing degree absorber, the high polishing degree TiO_2
reflector and the type of Y-11 WLS fibers bent with a curvature
radius of greater than 11 cm can significantly improve the light
output. In addition, electrons injected along the centre of tower
can make photons position distribution in SiPM more uniform. The
generation time of photons in scintillators and time of arrival at
the SiPM both obey the Landau distribution. Finally, the energy
resolution of tower can be better than 3.8%/√(E) (GeV) for a
Gaussian deviation's electron beam with an average energy of 3 GeV
and spread of 10% in the energy range.
Thickness-dependent phase transition kinetics in lithium-intercalated MoS2
Authors: Pondick Joshua V , Yazdani Sajad , Kumar Aakash , Hynek David J , Hart James L , Wang Mengjing , Qiu Diana Y , Cha Judy J 
Published: January 2022

Abstract
The phase transitions of two-dimensional (2D) materials are key to the operation of many devices with applications including energy storage and low power electronics. Nanoscale confinement in the form of reduced thickness can modulate the phase transitions of 2D materials both in their thermodynamics and kinetics. Here, using in situ Raman spectroscopy we demonstrate that reducing the thickness of MoS2 below five layers slows the kinetics of the phase transition from 2H- to 1T′-MoS2 induced by the electrochemical intercalation of lithium. We observe that the growth rate of 1T′ domains is suppressed in thin MoS2 supported by SiO2, and attribute this growth suppression to increased interfacial effects as the thickness is reduced below 5 nm. The suppressed kinetics can be reversed by placing MoS2 on a 2D hexagonal boron nitride (hBN) support, which readily facilitates the release of strain induced by the phase transition. Additionally, we show that the irreversible conversion of intercalated 1T′-MoS2 into Li2S and Mo is also thickness-dependent and the stability of 1T′-MoS2 is significantly increased below five layers, requiring a much higher applied electrochemical potential to break down 1T′-MoS2 into Li2S and Mo nanoclusters.