bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Synchronization Theory of the Vibration System of Four Circularly Symmetrical Vibrator
Authors: Zhang Nan , Zhang Sheng , Jia Yijun
Published: August 2023

This dissertation aims to study the synchronization properties of a vibrating system consisting of four oscillators, with three located equidistantly on the same circular trajectory and the fourth exciter situated at the center. This study is divided into three stages. Firstly, by utilizing the Lagrange equation, the dynamic model is developed for the research object, and the differential equation is derived when the body runs stable. Secondly, the differential equation obtained in the previous step is solved using Hamiltonian theory, and the solution of the equation is obtained. The necessary conditions required for the vibration system to achieve stable synchronization are also deduced. Finally, the accuracy of the synchronization characteristics is verified by using simulation techniques. The findings indicate that with specific prerequisites met, four motors can achieve synchronicity while the vibration system maintains stability and elliptical motion of the system centroid. These research outcomes establish a theoretical basis for the development of similar vibrational equipment.
Preparation of porous carbon nanowires for hydrogen evolution reaction
Authors: Xu Yuelong , Wang Shasha
Published: August 2023

Hydrogen for clean energy resources has attracted more and more attention, and water splitting for hydrogen production also has been widely studied. Electrocatalysis water splitting is considered the most efficient method for hydrogen production. In this work, we prepared a metal-free porous carbon nanowires catalyst with an electrostatic spinning method using granular poly styrol as the precursor and zinc chloride as the activating agent for forming a porous structure. The obtained catalysts exhibited a plentiful porous structure and an SSA value, which is beneficial for catalyzing hydrogen evolution reactions. The SSA is up to 329 m2 g−1, and the OP value at 10 mA·cm−2 is 386 mV. The materials presented good stability for hydrogen evolution reaction.
Study on the Influence of Strengthening Grinding Process on the Surface Integrity of 30CrMnSiA
Authors: Chen Xiujie , Liu Zhaoyang , Mai Tiannan , Liu Jiawei , Liang Biyu
Published: August 2023

30CrMnSiA, as a high-strength steel with excellent toughness and superior hardenability, was extensively used in the aerospace industry. At the same time, its lower surface hardness limits its application in impact and vibration environments. The surface of 30CrMnSiA was enhanced using the strengthening grinding process (SGP) technique in this work. The influence of SGP jet pressure on the surface integrity of 30CrMnSiA steel was studied, such as morphology, microstructure, roughness, and hardness. The study indicated that 30CrMnSiA samples treated by SGP reduced surface flatness, primarily due to the formation of plenty of irregular micro-pits by SGP. The greater the jet pressure leads to the more acute surface height fluctuation and the larger surface roughness. Furthermore, SGP notably enhanced the surface hardness and induced the formation of a strengthened layer. This improvement can be attributed to promoting martensite content and grain refinement within the surface layer structure facilitated by the SGP. The harder the surface hardness with the finer grain size, the thicker the strengthening layer with higher jet pressure.
The Microstructure and Properties of Ni60 cladding layer by Laser Cladding on TC4 Alloy Surface
Authors: Wang Fei , Li Xiao , Peng Jiahui , Liu Zengzhi , Feng Xinyi
Published: August 2023

Laser cladding was used to prepare a Ni60 cladding layer on the surface of TC4 alloy to enhance its hardness and wear resistance. Single-factor experiments were conducted to compare the effects of laser power, powder feeding speed, and scanning speed on the morphology, dilution rate, and microhardness of the Ni60 cladding layer. Based on fewer cracks, high hardness, and moderate dilution rate, the optimum parameters were determined. According to the results, when the laser power was 1000 W, powder feeding rate was 1.8 r/min, and scanning speed was 6 mm/s, the Ni60 cladding layer was crack-free, bonded to the TC4 substrate by metallurgical means, with a columnar and equiaxed crystalline microstructure, consisting of γ-Ni, Cr3C2, TiC, TiNi, Cr3Ni12 phases, etc. Compared to the TC4 substrate, the Ni60 cladding layer is about 2.30 times harder with an average microhardness of 836.71 HV1. Ni60 cladding layer and TC4 substrate had friction coefficients of 0.39 and 0.63, the weight loss was 21 mg and 115 mg, and the wear mechanisms were abrasive wear and adhesive wear, respectively. According to the results, the Ni60 cladding layer effectively enhances the TC4 substrate’s microhardness and wear resistance.
Surface Quality and Microstructure of Welded Joint of 12Cr1MoV Steel by Ultrasonic Peening
Authors: Zhou HongYang , Hou XingLong , Liu Xin , Jiang Tao , Zhang ZhaoLiang , Yang Bahu
Published: August 2023

The Ferrite heat-resistant steel 12Cr1MoV is extensively used for structural applications in thermal power plants due to its good strength, weldability and long-term stability. The components often undergo fatigue loading, which leads to premature failure. In most cases, fatigue cracks usually initiate from the surfaces of structural components. Hence, surface strengthening treatment is a necessary procedure to improve fatigue performance. In general, ultrasonic peening is treated as an important means of improving fatigue properties. In this study, the effect of ultrasonic peening on the microstructure evolution of 12Cr1MoV steel in service was investigated. Work hardened layer and plastic deformation layer with nanocrystals were generated in the 12Cr1MoV surface after ultrasonic peening treatment. The nanocrystallization process of grains was deeply discussed. The variation of fatigue notch coefficient under different ultrasonic peening parameters was analyzed in detail. The results show that ultrasonic peening can optimize the geometry of the weld toe and reduce the fatigue notch coefficient. In addition, after the UIT1 parameter treatment, the depth of ultrasonic peening on the base material can reach about 220 um, and after the UIT2 parameter treatment, the depth of impact on the base material can reach about 250 um. Compared with the original sample, the hardness of UIT1 increases by 20% and UIT2 increases by 26% at the depth of 0.1mm. Grains are refined to about 200 nm in the topmost surface after ultrasonic peening treatment. The mechanism of nanocrystallization is mainly due to dislocation motion.
Modeling on the Flatness of Silicon Wafers Ground by the Grind-polishing Wheel
Authors: Wu Zihe , Cheng Jirui , Zhang Yu , Ren Jiawei , Gao Shang
Published: August 2023

The grind-polishing wheel is a new non-woven structure grinding tool with low elastic modulus and ultra-fine abrasive grains, which can obtain high surface/sub-surface quality ground silicon wafers. To obtain high-shape flatness during grinding with the grind-polishing wheel, a prediction model of the ground silicon wafers’ flatness considering the elastic modulus of the wheel, processing parameters, and abrasive grain size is developed. The grinding experiments under different speed ratios were conducted to verify the prediction model accuracy. It shows that the model can successfully predict the flatness of ground silicon wafers, and the error of the prediction model is less than 13%. The proposed model has some guiding significance for choosing the appropriate character of the grind-polishing wheel and grinding parameters to achieve desirable flatness for silicon wafers.
Field-driven energy control scanning method for selective laser melting lattice structures
Authors: Wang Senlin , Qin Lin , Zhang Lichao , Zhang Zihua
Published: August 2023

While processing metal lattices, the selective laser melting (SLM) technique is prone to flaws such as warping, dross, and low forming dimensional accuracy due to the inhomogeneity of the temperature field during the forming process. This paper proposed a field-driven energy control scanning method. The energy control factor field is calculated by the hemispherical convolution operator in voxel space according to the signed distance field of the model combined with the material thermal conductivity. The optimized variable process parameter field data is obtained by coupling with the initial process parameter field. The laser power on the metal lattice scanning path can be precisely controlled by domain and segment. The experimental results show that the surface roughness of the variable-parameter printed gradient lattice is much better than that of the single-parameter printed lattice, and the compressive mechanical characteristics of the lattice are nearly doubled.
Simulation of microstructure evolution process in the melt pool formed by laser cladding with a multi-scale model
Authors: Jin Kangning , Chen Ping
Published: August 2023

The microstructure directly determines the alloys’ mechanical performance, therefore understanding the microstructure evolution process is essential to controlling the cladding layer’s mechanical performance. A multiscale model in three dimensions is developed to evaluate the complicated microstructure evolution in the melt pool formed during the laser cladding process. The model consists of two parts: the FVM to calculate the evolution of the melt pool at the macroscopic scale, and the simulation of the solidification of grains at the microscopic scale by the CA. The high consistency with the experimental results proves the accuracy of the multiscale model in three dimensions. Using the developed model, the solid-liquid phase transformation process of the whole melt pool is studied and the impact of the variations of scanning speed on the microstructure is analyzed. The grain size decreases and the “laser-grain angle” increases with an increase in scanning speed. This study explains the evolution of the microstructure, which helps to customize the cladding layer’s microstructure.
Simulation study on the effect of different wavelengths of laser on graphitization of diamond surface
Authors: Yuan Huixin , Song Chengwei , Zhang Chunyu , He Zhibing , Li Guo , Zhang Junjie , Qin Wentao
Published: August 2023

A temperature field simulation study of CVD diamonds under nanosecond laser processing was carried out to investigate the characteristics of diamond graphitization and material removal mechanisms during nanosecond laser processing. Experimental results show that diamond undergoes significant burn and graphitization during laser processing. The graphite layer thickness and width of the diamond surface were measured to determine the regularity of nanosecond laser-induced diamond graphitization. Analysis of the simulation results for the diamond temperature profile shows that the nanosecond laser irradiation energy is mainly distributed over the diamond surface, and the thermal effect zone of nanosecond laser irradiation on the diamond is small, resulting in a graphite layer thickness of about 3.25 μm.
The Causes of Explosion Failure of Liquid Ammonia Cylinder
Authors: Ren Facai
Published: August 2023

Gas cylinders are widely used in industrial production and daily life. Due to the complexity of the medium contained in the cylinder and the unsafe factors in the use and management, cylinder accidents occur more frequently. This paper analyzes the cause of a burst accident in the liquid ammonia cylinder. The results show that the chemical composition and mechanical properties of cylinder materials basically meet the requirements of relevant standards. No obvious defects were found on the weld and fracture surface during NDT. The outer surface of the gas cylinder is severely corroded, especially in the weld area, where there is a lot of pitting corrosion.
Ultrasonic-assisted Pulsed TIG Welding (U-P-TIG) of Inconel 690 for Nuclear Power Plants
Authors: Xia Xiaowei , Wen Wei , Shen Xu , Wu Jiefeng , Lyu Hongjun
Published: August 2023

Inconel 690 has been extensively used in steam generator tubing materials for pressurized water reactors. In order to improve the weld quality of Inconel 690, ultrasonic-assisted pulsed tungsten inert gas (TIG) welding is studied. In this study, the macrostructure, microstructure, and mechanical properties of Inconel 690 weldments welded by TIG welding with and without ultrasonic assistance were investigated. The microstructures of the fusion zone (FZ) and heat-affected zones (HAZ) were examined by an optical microscope and the Electron Backscatter Diffraction (EBSD) technique, and weldment properties were compared through tensile and impact tests. Experimental results indicate that the base metal (BM) was composed of equiaxed crystalline austenite, and the austenite grains in the heat-affected zone were obviously grown; the fusion zone (FZ) was composed of columnar austenite. Besides, the ultrasonic assistance was effective in refining the structure and improving the strength and toughness of weld metal.
Effect of Nb on the Hydrogen-induced Cracking of X80 Pipeline Steel
Authors: Fan Yanqiu , Ma Changwen , Li Shaopo , Ding Wenhua , Wang Longhe , Liu Yang , Li Zhanjun
Published: August 2023

Nb is a key alloying element added into X80 pipeline steel, and it can enhance mechanical properties by refining grains and introducing precipitates. However, HIC resistance is also one of the most significant performances for pipeline steel served in H2S environment. An all-inclusive recognition of the response of niobium to HIC refusal is important for the appropriate design of the Nb addition amount, the rolling and cooling parameters, and protective techniques to obtain excellent mechanical properties, including strength and ductility and HIC refusal. So in the paper, many test methods, such as EBSD, SEM, and HIC, were adopted to research the response of niobium addition on resistance of hydrogen-induced cracking performance of X80. As the increase in Nb content, grain size decreased and had the strongest trapping hydrogen atom ability. Besides, the percentage of low-angle grain boundaries went up, and more precipitates greatly raised the amount of irreversible hydrogen pitfalls. Nb could greatly promote the HIC resistance, inhibiting crack initiation, and propagation.
Microstructure Characteristics of TP304 Steel after Long-time High-temperature Service
Authors: Song Tao , Wang Zhiwu
Published: August 2023

The microstructure characteristics of specimens used for 1.5×104 h, 7.8×104 h, and 9×104 h and a burst tube specimen used for 8.5×104 h were analyzed by a metallographic microscope, a scanning electron microscope, and energy spectrum, and the precipitated phase was quantitatively analyzed by ImageJ. The results show that the second phase precipitates at grain boundaries and within grains after service. During operation, chrome-rich carbides precipitate along grain boundaries, which gradually aggregate and grow into chains, forming intergranular corrosion, resulting in intergranular cracking, and the σ-phase precipitates at severe overtemperature.
Study on the Effect of Remelt Scanning and Heat Treatment Processes on the Structure and Properties of Laser Powder Bed Fusion Formed Al-Mg-Sc-Zr Alloys
Authors: Zhou Zijie , Chen Chao , Guan Jieren , Yuan Kang
Published: August 2023

Laser Powder Bed Fusion (LPBF) technology was used to form Al-Mg-Sc-Zr alloys to investigate the effects of remelting scanning and heat treatment processes on their tissue evolution and mechanical properties. The results show that the surface roughness (Sa) of the upper surface of the unmelted and once-remelted scans are similar. In contrast, the surface roughness (Sa) of the upper surface of the twice-remelted scans is significantly higher. The surface roughness (Sa) of the specimen sides gradually increases with the number of scans. The Al-Mg-Sc-Zr alloy has a unique mixed crystal structure, with many Al3(Sc, Zr)-L12 precipitates precipitating at the melt pool boundary to promote the formation of fine equiaxed crystals.

In contrast, the interior of the melt pool is a coarse columnar crystal structure due to the low precipitation of Al3 (Sc, Zr)-L12 precipitates. After heat treatment, more Al3 (Sc, Zr)-L12 precipitates will precipitate inside the melt pool. After the aging heat treatment, the specimens’ yield and tensile strength increased significantly while the elongation at break decreased.
Microstructure Characterization and Failure Mechanism of Laser Welded Nuclear-grade FeCrAl Alloy
Authors: Zhan Yaqi , Niu Yitian , Hu Yanying , Zhang Ruiqian , Ma Xianfeng , Liu Jinping , Feng Yingchao
Published: August 2023

FeCrAl alloy is considered a new type of promising accident-tolerant fuel cladding material. Laser welding technology, which has been widely applied in the connection of various metal materials, uses a high energy density laser heat source with the advantages of efficiency and precision. However, due to the inherent characteristic of high speed, the laser weld is generally exposed to rapid solidification, resulting in the inevitable formation of defects such as coarse grain size and porosity in the weld. The presence of pores is a troublesome question because they will reduce the bearing area of the joint and accelerate the initiation of cracks, resulting in a significant reduction of the tensile strength. Based on these considerations, in this study, the effect of pores on laser-welded nuclear-grade FeCrAl alloy is investigated by quasi-in-situ tensile testing, and the fracture mechanism of the joint is revealed. The maximum ultimate tensile strength measured by the experiment is 550 MPa, and the elongation of welds is 9.6%. In addition, there are obvious stress concentrations and cracking phenomena generated in the vicinity of a pore. The joint is eventually fractured in the fusion line near the fusion zone. A large number of pores can be found at the fracture failure position from the fracture morphology observation, indicating that the pores are presumably to be the intrinsic reason for the cracking of the welded joints.
Cooling Coating for Buildings Based on the Daytime Radiative Cooling Technology
Authors: An Yizhuo , Sun Junyu , Ji Cheng , Wang Jing
Published: August 2023

In order to investigate the cooling effect of the radiative cooling material in the form of coating applied to buildings, a fiber-reinforced calcium silicate plate covered with radiative cooling coating was prepared on the basis of solving the bonding strength of coating in the research. The plate was used as the roof for the building model. The temperature at the face center on the inside of the roof and the inner body center of the building was tested on sunny and hot summer days. The results show that in the continuous 48-hour monitoring process, the radiative cooling coating can achieve a cooling effect of up to 28.8 °C at the backside of the roof, and 20.8 °C inside the building compared with an ordinary building without coating. Moreover, the coating also shows a sub-ambient cooling effect of 9.8 °C, even allowing the temperature inside the building to be lower than the air temperature under the shade.
Research on microstructure variation of laser melting deposition Ti-6Al-4V under electroshocking treatment
Authors: Bi Jian , Sun Hongxin , Wen Yan
Published: August 2023

In this work, electroshocking treatment (EST) was applied to Ti-6Al-4V prepared by laser melting deposition (LMD), and the microstructure and grain size were investigated. The size of the α phase was reduced, and the content increased after the EST treatment.
Target Information Acquisition Method of Penetration Fuze Based on Composite Detection
Authors: Zhang Zhenze , Sui Li , Yu Haoyuan , Shi Gengchen
Published: August 2023

When the traditional high-g acceleration sensor penetrates the hard multi-layered target, it is easy to cause the overlap of the penetration overload. The rigid body signal is submerged in the vibration signal, resulting in the error of the layer-counting recognition algorithm, and it is difficult to judge the time of the penetration ammunition. Based on the principle of the capacitance sensor and the piezoelectric sensor, a composite sensor for penetration fuze is designed in this paper. On this basis, a layer-recognition algorithm based on capacitance and piezoelectric signal fusion is designed, and its feasibility is verified by software simulation.
Numerical Simulation Verification of the Application of Inorganic Thermal Insulation Materials to the Surrounding Rock of Roadways
Authors: Jian Junchang , Luo Wei , Liu Heng , Jiang Yewei
Published: August 2023

Insulation materials provide a new solution for heat dissipation control in high-temperature mine enclosures. In this paper, ANSYS Fluent was selected to conduct a numerical simulation study on the heat transfer after inorganic insulation materials were laid on the surface of the mine tunnel surrounding rock. The results show that the influence of the tunnel wind flow on the temperature of the surrounding rock is related to the support material laid, and the temperature of the surrounding rock wall after laying inorganic insulation material is about 4°C lower than that of ordinary concrete support. The temperature difference of the surrounding rock wall at the entrance of the tunnel is about 4.6°C, and that of the surrounding rock wall at the exit is about 2.8°C. The comparative analysis verifies that the insulation material positively affects the heat dissipation control of the high-temperature shaft and the surrounding rock of the roadway.
Study on the friction reduction characteristics of surface micro-pit weave under fluid lubrication conditions
Authors: Zhou Xiangyuan , Wang Jian
Published: August 2023

As for the improvement and improvement of tribology, numerous literature studies have shown that certain surface roughness is conducive to enhancing the dynamic pressure lubrication effect and reducing the frictional wear between frictional pairs. The design of a micro-loom with a reasonable characteristic size significantly brings out its friction reduction performance. The CFD software ANSYS Fluent was used to numerically analyze the hydrodynamic pressure on the surface of the micro-loom to obtain the oil film load-bearing force generated by the relative sliding on the surface of the friction pair and to analyze the effect of the depth of the micro-crater on the tribological performance. The results show that the coefficient of friction rises first and then decreases with the increase of the depth of the micro-pit within the given weaving parameters, the maximum bearing capacity is 0.088 N when the depth of the micro-pit is 4 μm, and only 0.086 N when the depth is 10 μm.
The molding of the ceramic solid electrolyte sheet prepared by tape casting
Authors: Dai Baoxin , Zhou Man , Liu Kaige , He Bin , Xiang Bingxi , Kong Lingbing
Published: August 2023

Ceramic oxide solid-state electrolytes are more popular among researchers because of their excellent thermal stability, wide electrochemical window, excellent lithium-ion conductivity and high elastic modulus. Lithium-ion solid-state batteries with tantalum-doped Li6.4La3Zr1.4Ta0.6O12 (LLZTO) inorganic ceramic electrolytes have attracted much attention due to their extraordinary lithium-ion conductivity, incombustibility, and wide electrochemical window. Tape casting is a common method for ceramic molding, which is mainly used to prepare ceramic packaging substrate. However, the preparation process of casting slurry is tedious and time-consuming. In this study, a one-step vibration ball-milling method was proposed to prepare a non-aqueous-based casting slurry, which only took 2 hours. By optimizing the process parameters, the LLZTO solid electrolyte film prepared by tape casting had a uniform texture, and its thickness could be as thin as several microns. The perovskite-type LLZTO-independent ceramic electrolyte film with a thickness of 83 μm was prepared by tape casting. The Li+ ionic conductivity of the LLZTO solid-state electrolyte membrane is 2.0×10−5 S·cm−1. The Li-symmetric battery with all-solid-state lithium assembled using 83 μm thick LLZTO exhibited stable Li deposition and stripping properties.
Verification of Optical Fiber Multiparameter Sensing Technology for High Temperature Environment
Authors: An Wanqing , Pan Shangjie , Li Chao , Zhang Yuchang , Ma Ziliang , Liu Zhe
Published: August 2023

Aiming at the measurement problems such as strain in high temperature environment, this paper builds an optical fiber sensor that is suitable for high temperature environment. A test system platform that can provide a high temperature environment of 1000 °C both dynamic and static strain loading is designed. The platform includes a high-temperature furnace, constant-strength beams and excitation devices. Based on the test system platform, the thermal strain and loading strain tests of the high temperature fiber optic sensor are completed.
Experimental Study on the Influence of Model Parameters on the Dimensional Deviation of Printed Parts
Authors: Zeng Lianghua , Wu Wenxiong , Zou Xinfeng
Published: August 2023

Not being affected by the structural complexity of the print model is one of the outstanding features of 3D printing, but model parameters have an important influence on the dimensional accuracy of the printed parts. In order to explore the influence of model parameters on dimensional deviation, on the basis of designing experimental models and carrying out printing experiments, we have studied the effect of three model parameters (placement method, two-dimensional contour components, and model inclination) on printing accuracy through the dimensional deviation rate. It has been found that the inclination angle of the model mainly affects the dimensional error in the height direction; different models can change the filling method of the cross-section contour from a curve to a straight line by changing the placement method, which can reduce the dimensional error of the two-dimensional contour of the model; the contour composed of linear elements has a lower deviation rate than the contour composed of curved elements.
The Residual Stress Control of Thin-walled Sleeve Parts with Weak Rigidity
Authors: Tian Yao , Sun Pengcheng , Ge Yingchun , Wang Zhibin , Zhang Zheng , Mai Yuying , Su Jun , Zhao Jin , Wang Zhangli
Published: August 2023

Photoelectric products in the military industry tend to be lightweight in design, requiring the part to be lightweight and have high specific strength. As one of the structural parts of photoelectric products, the thin-walled sleeve part has the peculiarity of lightweight and thin wall thickness. Nevertheless, the residual stress during machining processing poses an adverse effect on the accuracy of the parts. In this paper, the influence of residual stress on the accuracy of the parts during the processing was studied. Before fine machining, the residual stress was reduced by artificial aging techniques and ultrasonic beam control methods. Finally, the effect of the two stress relief methods was evaluated according to the qualified rate of the processing accuracy of the parts. The research results show that the axial residual stress of the part is larger than the circumferential residual stress. Both artificial aging techniques and ultrasonic beam control can eliminate residual stress, and the ultrasonic beam control method is more targeted and uniform.
Development of completion tool pressure test control system
Authors: Sun Zhiyu , Zhao Lianyu , Wang Chenglin , Zhao Xiaolei
Published: August 2023

In oil exploitation, the completion tool is the key point to ensure the effective development of oil wells, and it must undergo strict pressure testing. Due to the high test pressure, there are potential safety hazards in the manual operation process. To improve safety and test efficiency, the automatic precision test system is developed. The detection system must realize the pressure detection process, provide feedback on the key data, give the corresponding curve reference, and generate the detection report. Through the PID algorithm, the precise control of the motor is realized. The system safety is guaranteed, and the detection accuracy is improved. The test results show that the completion tool pressure test control system can greatly improve detection efficiency. It can also fully reflect the entire detection process, accurately calculate some key parameters such as pressure drop, and obtain accurate results. The detection error is kept within 0.5%, ensuring the reliability of the detection process.
Analysis of the Creep Failure of P92/HR3C Dissimilar Steel Welded Joint
Authors: Li Min , Liu Zhihao , Lu Ziming , Pan Weiguo , Xue Haibo , Shang Yongzhi
Published: August 2023

Harsh service environments, such as high temperature and pressure, cause many unforeseen premature failures, especially for welded joint structures, whose heat-affected zones have been in service. Cases of pressure vessel damage caused by premature cracking in the process often occur. In this paper, the finite element model of dissimilar welded joints of P92/HR3C steel was established to simulate the actual service process, and the variation law of maximum principal stress, equivalent stress, and stress triaxiality on the inner and outer surfaces of the joint and both sides of the welding were analyzed. The results show that in the long-term use of welded joints, the stress concentration occurs in the weld fusion zone; with the increase in service time, the creep strength of the HR3C weld interface is much higher than the P92 weld interface, the structural shape changes and the stress concentration is transferred from the HR3C-weld to the P92-weld.
Influence of addition of Ti4822 powder on microstructure development of 316L stainless steel by SLM
Authors: Sun Pengyue
Published: August 2023

Ti4822 was added into 316Lss for selective laser melting leading to the form ferrite phase in the molten pool. The ferrite and its surrounding austenite undergo recrystallization and recovery.
Moisture absorption analysis of offshore wind turbine blade adhesive bonding under multi-environmental stresses
Authors: Shao Zhenjiang , Li Yongjie , Liang Jinlong , Liu Zheng
Published: August 2023

Due to long-term serving in harsh environmental conditions with high temperature, high humidity, salt fog, etc., the structural performance degradation of adhesive bonding in wind turbine blades will easily occur. Considering that material moisture absorption is closely related to structural performance, a study on moisture absorption of bonded structures under multi-environmental stresses is performed in this paper. In particular, 3 environmental stresses, the temperature, aging time, and saline concentration, are considered. A series of environmental aging tests are conducted using the variable control method. The moisture absorption properties are analyzed. The performance degradation laws of the bonded structure under the effects of multi-environmental stresses are obtained. The results are meaningful for structural performance investigation of offshore wind turbine blade adhesive bonding.
The effect of the accumulator on oil pressure shock suppression based on mill screw-down system
Authors: Luo Zhenkun , Wang Dandan , Peng Engao , Zhang Yongyang
Published: August 2023

This paper takes the servo valve front accumulator as the research object. It analyzes its effect in suppressing pressure shock and improving system pressure stability. Finally, it achieves the purpose of improving the control accuracy of the hydraulic screw-down system of the rolling mill. According to the actual operating requirements, the mathematical model of the servo valve front accumulator is established. The pressure shock suppression effect of the accumulator is simulated and analyzed with different parameters in the process of servo valve adjustment and reversal. Finally, it is verified by experiment. The optimal selection method of the parameters of the accumulator is obtained to provide theoretical and empirical support for the study of methods to enhance the system pressure stability and improve the control accuracy.
Design of Intelligent Robots Based on Body Sense Control
Authors: Li Zeyu , Wei Huibin , Zheng Zebin , Zhou Guiyu , Chen Yiqun , Yin Xinyan
Published: August 2023

Recognizing human actions to control the robot has become a challenging task. This paper provides a manipulator control system based on a mobile platform. The bending Angle of the specific connecting rod mechanism is collected to obtain the bending degree of the finger. The nine-axis gyroscope is used to detect the attitudes of the hand and the arm, and the data is transmitted to the HT32F5352 control board. Experimental results show that intelligent robots based on motion sensing can be equipped with automatic and manual control, environmental detection, and other functions.
Characterisation of the temperature-dependent dark rate of Hamamatsu R7081-100 10” photomultiplier tubes
Authors: Wilson S.T. , Fargher S. , Foster R. , Malek M. , Needham M. , Scarff A. , Smith G.D.
Published: August 2023

Dark noise is a dominant background in photomultiplier tubes (PMTs), which are commonly used in liquid-filled particle detectors for single-photon detection to see the results of particle interactions. A major contribution to dark noise is thermionic emission from the photocathode.

The dark noise of Hamamatsu R7081-100 PMTs is characterised in a temperature and purity controlled water tank, with the thermionic emission contribution isolated. The results suggest that the intrinsic dark rate of PMTs does not depend on the medium, but does follow Richardson's law of thermionic emission. There are external contributions to the overall observed PMT count rate identified, but the intrinsic PMT dark rate in water matches that measured in air.
Machine Learning-based reconstruction of single and double radiation source distribution using plastic scintillation optical fiber
Authors: Dai Dongrui , Geng Changran , Tang Xiaobin
Published: August 2023

In this study, we propose a novel method for reconstructing
the radiation distribution of a one-dimensional radioactive source
using Machine Learning (ML) algorithms and plastic scintillation
optical fiber. The wavelength spectrum unfolding technique is used
to estimate the source position accurately. We compare the accuracy
and time efficiency of three different algorithms, namely,
Generalized reduced gradient (GRG), Maximum likelihood expectation
maximization (MLEM), and ML, in the single-source and dual-source
cases. Our results demonstrate that MLEM algorithm has a shorter
reconstruction time with comparable accuracy of position and
intensity compared to GRG algorithm for single-source case. For
dual-source case, ML algorithm provides real-time estimation of
position and intensity with acceptable errors, while GRG algorithm
has a larger error in intensity estimation and longer computation
time. Our proposed ML algorithms offer useful guidance for practical
applications in radiation source location.
Climate change impacts and adaptation to permafrost change in High Mountain Asia: a comprehensive review
Authors: Baral Prashant , Allen Simon , Steiner Jakob F , Gurung Tika R , McDowell Graham
Published: August 2023

Changing climatic conditions in High Mountain Asia (HMA), especially regional warming and changing precipitation patterns, have led to notable effects on mountain permafrost. Comprehensive knowledge of mountain permafrost in HMA is mostly limited to the mountains of the Qinghai-Tibetan Plateau, with a strong cluster of research activity related to critical infrastructure providing a basis for related climate adaptation measures. Insights related to the extent and changing characteristics of permafrost in the Hindu Kush Himalaya (HKH), are much more limited. This study provides the first comprehensive review of peer-reviewed journal articles, focused on hydrological, ecological, and geomorphic impacts associated with thawing permafrost in HMA, as well as those examining adaptations to changes in mountain permafrost. Studies reveal a clear warming trend across the region, likely resulting in increased landslide activity, effects on streamflow, soil saturation and subsequent vegetation change. Adaptation strategies have been documented only around infrastructure megaprojects as well as animal herding in China. While available research provides important insight that can inform planning in the region, we also identify a need for further research in the areas of hazards related to changing permafrost as well as its effect on ecosystems and subsequently livelihoods. We suggest that future planning of infrastructure in HMA can rely on extrapolation of already existing knowledge within the region to reduce risks associated with warming permafrost. We highlight key research gaps as well as specific areas where insights are limited. These are areas where additional support from governments and funders is urgently needed to enhance regional collaboration to sufficiently understand and effectively respond to permafrost change in the HKH region.
The air pollution tradeoff in India: saving more lives versus reducing the inequality of exposure
Authors: Sankar Ashwini , Goodkind Andrew L , Coggins Jay S
Published: August 2023

Chronic exposure to ambient fine particulate matter (PM2.5) represents one of the largest global public health risks, leading to millions of premature deaths annually. For a country facing high and spatially variable exposures, prioritizing where to reduce PM2.5 concentrations leads to an inherent tradeoff between saving the most lives and reducing inequality of exposure. This tradeoff results from the shape of the concentration–response (C-R) function between exposure to PM2.5 and mortality, which indicates that the additional lives saved per unit reduction in PM2.5 declines as concentrations increase, suggesting that more lives can be saved by reducing exposures in clean locations than in dirty locations. We estimated this C-R function for urban areas of India, finding that a 10 µgm−3 reduction in PM2.5 in already-clean locations will reduce the mortality rate substantially (4.2% for a reduction from 30 to 20 µgm−3), while a 10 µgm−3 reduction in the dirtiest locations will reduce mortality only modestly (1.2% for a reduction from 90 to 80 µgm−3). Policymakers face a troubling tradeoff between maximizing lives saved and reducing the inequality of exposure. Many air pollution policies impose an upper limit on exposure, thereby cleaning the dirtiest locations and reducing exposure inequality. We explore the implications of this PM2.5/mortality relationship by considering a thought experiment. If India had a fixed amount of resources to devote to PM2.5 concentration reductions across urban areas, what is the lives saved/inequality of exposure tradeoff from three different methods of deploying those resources? Across our three scenarios: (1) which reduces exposures for the dirtiest districts, (2) which reduces exposures everywhere equally, and (3) which reduces exposures to save the most lives—scenario 1 saves 18 000 lives per year while reducing the inequality of exposure by 65%, while scenario 3 saves 126 000 lives per year, but increases inequality by 19%.
Improvement of human-induced wildfire occurrence modeling from a spatial variation of anthropogenic ignition factor in the CLM5
Authors: Cai Lei , Shi Wenwen , Shi Weiyu , Li Fang , Alexeev Vladimir A , Shiklomanov Alexander , Yang Ruowen , Tan Shucheng
Published: August 2023

Wildfire is an essential form of natural disturbance for the Earth system, and it is challenging for the current numerical models to accurately retrieve the spatiotemporal distributions of wildfire occurrence. One of the deficiencies could result from the parameterization of anthropogenic impact on wildfire occurrences. This study develops an approach to advance human-induced wildfire modeling by calibrating the parameter of human ignition count (HIC) in the fire module of the Community Land Model version 5. This study modifies the source code to allow a grid-scale variation of HIC. Sensitivity experiments with different grid-uniform HIC values are conducted to quantify the model biases with satellite-based observation data as the reference. The theoretically optimal HIC for each grid is obtained by linear rescaling the HIC based on the model biases in the sensitivity tests. The model evaluation takes place in southwest China where there is complex terrain and land use/land cover features. The involvement of grid-scale HIC significantly reduces the model bias in the climatology of wildfire occurrence. The pattern correlation coefficient increases from 0.57 to 0.78, and the root mean square error (RMSE) decreases from 0.58 to 0.18. The correlation coefficient of the annual sums of wildfire occurrences increases from 0.69 to 0.77, and the RMSE decreases from 560.8 to 146.4. A global-scale test verifies that such an approach can be extended to multiple regions with a reasonable scale of population density and economy.
Quantum evolution with random phase scattering
Authors: Ziegler K
Published: August 2023

We consider the quantum evolution of a fermion–hole pair in a d-dimensional gas of non-interacting fermions in the presence of random phase scattering. This system is mapped onto an effective Ising model, which enables us to show rigorously that the probability of recombining the fermion and the hole decays exponentially with the distance of their initial spatial separation. In contrast, without random phase scattering the recombination probability decays like a power law, which is reflected by an infinite mean square displacement. The effective Ising model is studied within a saddle point approximation and yields a finite mean square displacement that depends on the evolution time and on the spectral properties of the deterministic part of the evolution operator.
Impact of Electric Vehicles toward Energy Reliability of the Jawa-Madura-Bali Electrical Power System
Authors: Tampubolon Joshua Veli , Dalimi Rinaldy
Published: August 2023

There is an observed limitation in the number of electric vehicles using batteries as power sources (e.g., plug-in electric vehicles) in Indonesia. While the number of said electric vehicles is increasing in response to the government’s commitment to shift the transportation energy source towards electric energy for a more sustainable environment, this change is followed by an inevitable impact on the current electric network and infrastructure. Indonesia’s government predicted that there will be around 20 million 2-wheelers and 4 million 4-wheelers ICE by the year 2030 with an additional load of 29.300 MW to be expected. Lessons learned from other countries have shown that the abrupt changes in the supply-demand energy for the electric vehicle, such as the deficit/surplus of energy or the duck curve phenomena, create an urgency to prevent the said phenomena and the potential financial loss that might have cross-sectoral impacts. Through an analysis of the Jawa-Madura-Bali system, an independent system that can produce 30.970 MW by the year 2020 [1], the paper focuses on the impact of this system in developing an adaptive infrastructure to address increased power needs for electric vehicles in Indonesia. Literature review and data analysis shows that the impact of Electric Vehicles on the Energy Reliability of the Jawa-Madura-Bali Electrical Power System is very pronounced. The amount of energy needed for the grid to be reliable in the EV transition is significantly higher than the natural growth of the grid energy supply. It is feasible that the increasing electricity demand from EVs could be offset by adding more renewable energy sources to the grid. Renewable energy sources, such as solar and wind, (both centralized and decentralized) can help to offset the insufficient total energy supply growth from the conventional power producer. One approach to address these challenges is to continue the development of mixed renewable and non-renewable energy sources, allowing the grid to draw on a variety of sources as needed to meet demand. This development can help to ensure a reliable and stable supply of electricity to meet the needs of electric vehicles and other customers. A supply-demand simulation and prediction, which could be a very helpful tool in the conceptualization of a management plan for the energy system to mitigate the imbalance of supply and demand of electric energy supply should be developed.
Optimization and simulation of a grid-connected PV system using load forecasting methods: A case study of a university building
Authors: Manlapaz Juan Glicerio C. , Reyes Dalisay M. , Buensuceso Cris Paulo L. , Peña Robert Alfie S. , Parocha Raymark C. , Macabebe Erees Queen B.
Published: August 2023

Distributed generation represents a paradigm shift from the traditional electric grid to localized generation of electric power along with the capability of incorporating renewable energy (RE) sources into the energy mix. Responding to the need for sufficient analysis, simulation, and study of feasibility of distributed generation, this study aims to design a hybrid energy system for a university building and analyze its economic benefits. The viability of existing load forecasting methodologies for energy systems is also presented in this paper. The energy system design was determined through predictive modeling of the load profile of the building using historical data and optimization using machine learning methods, namely auto-regressive integrated moving average (ARIMA) and long short-term memory (LSTM). Simulations were run in HOMER Pro. Results show that a grid-connected solar photovoltaic (PV) system installed on the roof coupled with an energy storage system (ESS) will provide the most economic benefits because it yields a reduced cost of energy (COE) per kilowatt-hour (kWh) for the building. This study shows that in line with efforts to transition towards clean energy, hybrid energy systems using RE not only have economic benefits, but can also ensure energy security and environmental sustainability.
Projection of Carbon Emissions from the Diesel, Biodiesel, and Battery Electric Vehicle in Indonesia: A Policy Scenario Analysis for Decarbonization of Transportation Sector
Authors: Rahmaditio M R , Gardian P I
Published: August 2023

The Indonesian government is intensifying the mandatory biodiesel program to achieve the carbon emission reduction target. Although the emissions from the use of biodiesel are lower than diesel, its rapid development has raised concerns about other environmental issues, such as deforestation, hydrological disturbances, and biodiversity. At the same time, the global trend of electric cars offers a new alternative to the decarbonization of the transportation sector. Therefore, this study aims to compare the carbon emission reduction of biodiesel and electric vehicle policy scenarios. The baseline scenario is defined as full usage of diesel. The projection is conducted until 2060 using a model built with Vensim software. As a result, the biodiesel program with a 30% blending rate (B30) only reduced carbon emissions by 6.14 and 11.26 million tons in 2030 and 2060, respectively. Higher emissions reduction can be achieved by increasing the blending rate to 50% and 100%. On the other hand, emission reduction from electric vehicles program is very dependent on the energy mix of electricity generation. Under the 2021–2030 National Electricity Supply Business Plan (RUPTL) target, the electric vehicle scenario would produce higher emissions than the baseline scenario. However, there is a potential emission reduction of up to three times larger than B100 by the electric vehicle (EV) scenario if the EV transition is accompanied by an ambitious energy transition.