bluuebunny/crossref_metadata_2025 huggingface dataset:
Meta-lens based on multi-level phase-change
Authors: Zhang Jing Cheng , Yao Jin , Tsai Din Ping
Published: August 2024

Given the significant progress in the field of meta-lenses over the past decade, tunable meta-lenses have garnered considerable attention for their flexible functionality. Various mechanisms have been developed to realize high-performance tunable meta-lenses, including electricity, strain, thermal effects, and materials, such as phase-change materials and liquid crystals. However, currently, most tunable meta-lenses are limited to discrete focal lengths, typically only involving two spots, and the potential of phase-change materials, such as Ge2Sb2Te5, Sb2S3, etc., has not yet been fully exploited. Here, we propose a design approach to achieve tunable meta-lenses with continuous focal length manipulation working at 1550 nm based on phase-change materials (Sb2S3). The focal length can be gradually tuned from 35 to 55 μm during the conversion process between crystalline and amorphous states. The meta-atoms are rectangular shapes of different sizes and orientations to provide certain phase compensations from propagation and Pancharatnam–Berry phases, respectively. The tunable Airy beam, Bessel beam, and deflection of the meta-lens focal spot are also demonstrated to show the universality of the proposed design. This endeavor will lay the groundwork for the design of tunable meta-devices, thereby streamlining their integration into infrared systems.
Sm-doped PZT thin film with high piezoelectric properties by sol-gel method
Authors: Ti Jinming , Li Junhong , Fan Qingqing , Yu Qing , Ren Yuhan , Wang Chenghao
Published: August 2024

In this study, Pb(Zr0.54Ti0.46)O3 films were prepared by the sol-gel method with Sm doping concentrations of 0, 0.5, 1, 1.5, 2, and 3 mol. %. Their surface morphology, density, crystal structure, piezoelectric, dielectric, and ferroelectric properties were characterized. The results indicated that, unlike Sm-doped lead zirconate titanate (PZT) ceramics, all Sm-PZT films exhibit a significant increase in the grain size compared to undoped PZT films. Moreover, Sm doping affected their crystal orientation and significantly enhanced their piezoelectric coefficient d33 and remnant polarization (Pr). Notably, the Sm-PZT film with a doping concentration of 1.5 mol. % exhibited optimal (100) orientation, achieving a high piezoelectric coefficient d33 of 279.87 pm/V, 4.55 times that of the non-doped PZT films.
Fermilab goes deep to silence noisy radiation affecting qubits
Authors: Means Hannah H.
Published: August 2024

Scientists troubleshoot to improve quantum computers.
Unraveling clonal CD8 T cell expansion and identification of essential factors in γ-herpesvirus-induced lymphomagenesis
Authors: Gong Meijiao , Myster Françoise , Azouz Abdulkader , Sanchez Sanchez Guillem , Li Shifang , Charloteaux Benoit , Yang Bin , Nichols Jenna , Lefevre Lucas , Javaux Justine , Leemans Sylvain , Nivelles Olivier , van Campe Willem , Roels Stefan , Mostin Laurent , van den Berg Thierry , Davison Andrew J. , Gillet Laurent , Connelley Timothy , Vermijlen David , Goriely Stanislas , Vanderplasschen Alain , Dewals Benjamin G.
Published: August 2024

Alcelaphine gammaherpesvirus 1 (AlHV-1) asymptomatically persists in its natural host, the wildebeest. However, cross-species transmission to cattle results in the induction of an acute and lethal peripheral T cell lymphoma-like disease (PTCL), named malignant catarrhal fever (MCF). Our previous findings demonstrated an essential role for viral genome maintenance in infected CD8
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T lymphocytes but the exact mechanism(s) leading to lymphoproliferation and MCF remained unknown. To decipher how AlHV-1 dysregulates T lymphocytes, we first examined the global phenotypic changes in circulating CD8
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T cells after experimental infection of calves. T cell receptor repertoire together with transcriptomics and epigenomics analyses demonstrated an oligoclonal expansion of infected CD8
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T cells displaying effector and exhaustion gene signatures, including GZMA, GNLY, PD-1, and TOX2 expression. Then, among viral genes expressed in infected CD8
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T cells, we uncovered A10 that encodes a transmembrane signaling protein displaying multiple tyrosine residues, with predicted ITAM and SH3 motifs. Impaired A10 expression did not affect AlHV-1 replication in vitro but rendered AlHV-1 unable to induce MCF. Furthermore, A10 was phosphorylated in T lymphocytes in vitro and affected T cell signaling. Finally, while AlHV-1 mutants expressing mutated forms of A10 devoid of ITAM or SH3 motifs (or both) were able to induce MCF, a recombinant virus expressing a mutated form of A10 unable to phosphorylate its tyrosine residues resulted in the lack of MCF and protected against a wild-type virus challenge. Thus, we could characterize the nature of this γ-herpesvirus-induced PTCL-like disease and identify an essential mechanism explaining its development.
Multilayer Ge8Sb92/Ge2Sb2Te5 thin films: unveiling distinct resistance states and enhanced performance for phase change random access memory
Authors: Liu Liu , Li Anding , Chen Yukun , Liu Ruirui , Xu Jiayue , Zhai Jiwei , Song Zhitang , Song Sannian
Published: August 2024

This study investigates the phase-change properties of [Ge8Sb92 (25 nm)-Ge2Sb2Te5 (25 nm)]1 multilayer thin films, elucidating three distinct resistance states originating from two structural transitions: initial Sb precipitation and Ge2Sb2Te5-FCC crystallization, followed by Ge2Sb2Te5-FCC to Ge2Sb2Te5-HEX transformation with additional Sb precipitation. The phase transitions induce two abrupt changes in resistance at temperatures of 169.8 °C and 197.7 °C, respectively, with corresponding data retention temperatures of 97 °C and 129 °C, indicating robust thermal stability. The [Ge8Sb92 (25 nm)-Ge2Sb2Te5 (25 nm)]1-based phase change random access memory (PCRAM) device demonstrates reversible switching characteristics and multi-level storage capabilities within 20 ns, showcasing enhanced phase-change speed and storage density. In summary, [Ge8Sb92(25 nm)-Ge2Sb2Te5(25 nm)]1 demonstrates enhanced thermal stability, swift phase transition, and increased storage density relative to conventional Ge2Sb2Te5, establishing it as a promising new phase-change material for PCRAM applications.
Theoretical insights into the structures and fundamental properties of pnictogen nitrides
Authors: Wang 王 Jingjing 晶晶 , Kong 孔 Panlong 攀龙 , Zhang 张 Dingmei 定梅 , Gao 高 Defang 德芳 , Jiang 蒋 Zaifu 再富 , Dai 戴 Wei 伟
Published: August 2024

Recent experimental advancements reported a chemical reaction between antimony and nitrogen under high temperature and high pressure, yielding crystalline antimony nitride (Sb3N5) with an orthorhombic structure. Motivated by this statement, we calculate the stability, elastic properties, electronic properties and energy density of the Cmc21 structure for pnictogen nitrides X
3N5 (X = P, As, Sb, and Bi) using first-principles calculations combined with particle swarm optimization algorithms. Calculations of formation enthalpies, elastic constants and phonon spectra show that P3N5, As3N5 and Sb3N5 are thermodynamically, mechanically and kinetically stable at 35 GPa, whereas Bi3N5 is mechanically and kinetically stable but thermodynamically unstable. The computed electronic density of states shows strong covalent bonding between the N atoms and the phosphorus group atoms in the four compounds, confirmed by the calculated electronic localization function. We also calculate the energy densities for Sb3N5 and find it to be a potentially high-energy-density material.
Probing nickelate superconductors at atomic scale: A STEM review
Authors: Lei 雷 Yihan 一涵 , Wang 王 Yanghe 扬河 , Song 宋 Jiahao 家豪 , Ge 葛 Jinxin 锦昕 , Wu 伍 Dirui 迪睿 , Zhang 张 Yingli 英利 , Li 黎 Changjian 长建
Published: August 2024

The discovery of nickelate superconductors, including doped infinite-layer (IL) nickelates RNiO2 (R = La, Pr, Nd), layered square-planar nickelate Nd6Ni5O12, and the Ruddlesden–Popper (RP) phase La3Ni2O7, has spurred immense interest in fundamental research and potential applications. Scanning transmission electron microscopy (STEM) has proven crucial for understanding structure–property correlations in these diverse nickelate superconducting systems. In this review, we summarize the key findings from various modes of STEM, elucidating the mechanism of different nickelate superconductors. We also discuss future perspectives on emerging STEM techniques for unraveling the pairing mechanism in the “nickel age” of superconductivity.
Spectroscopic Observations of Ten Galactic Wolf–Rayet Stars at Bosscha Observatory: Determination of Stellar Parameters and Mass-loss Rates
Authors: Malasan Hakim Luthfi , Setyo Budi Bakuh Danang
Published: August 2024

We present optical spectra of 10 Galactic Wolf–Rayet (WR) stars that consist of five WN and five WC stars. The optical observation was conducted using a low-resolution spectrograph NEO-R1000 (λ/Δλ ∼ 1000) at GAO-ITB RTS (27.94 cm, F/10.0), Bosscha Observatory, Lembang. We implemented stellar atmosphere Postdam Wolf–Rayet (PoWR) grid modeling to derive stellar parameters. The normalized optical spectrum can be used to find the best model from the available PoWR grid, then we could derive stellar temperature and transformation radius. To derive luminosity, stellar radius and color excess, we conducted a Spectral Energy Distribution (SED) analysis with additional data on the near-ultraviolet spectrum from the International Ultraviolet Explorer (IUE) database, and UBV and 2MASS JHK broadband filter data. Additional analysis to derive asymptotic terminal wind velocity was conducted from the P-Cygni profile analysis of the high-resolution IUE ultraviolet spectrum. With previously derived parameters, we could determine the mass loss rate of the WR stars. Furthermore, we compared our results with previous work that used PoWR code and the differences are not more than 20%. We conclude that the PoWR spectral grid is sufficient to derive WR stellar parameters quickly and could provide more accurate initial parameter input to the PoWR program code.
Optimization of mobile emergency resource scheduling after power grid failure based on real-time traffic flow
Authors: Liu Tianze , You Yang , Li Wanyuan , Liu Xinli , Pan Song , Yuan Ting
Published: August 2024

Given the increasing threat of reliability challenges in new energy networks from frequent natural disasters, our study focuses on the tactical placement of mobile emergency assets. We introduce an advanced scheduling model tailored for mobile emergency resources within traffic networks, taking into account the dynamic state of traffic flow. Our main goal is to enhance travel time efficiency for crucial vehicles. Through this approach, we devise a strategy for emergency resource allocation, covering both the path and schedule for deploying mobile emergency assets. This approach is designed to mitigate traffic congestion, thereby enhancing the efficiency and reliability of power grid fault remediation. The efficacy of our proposed model is substantiated through a case study involving a 12-node traffic network, demonstrating its potential to improve disaster response measures significantly.
Research on performance optimization and application scenarios of grid-following converter based on anti-windup control strategy
Authors: Zhang Jie , Chen Junru , Si Wenjia
Published: August 2024

With the widespread application of power electronic devices in the power system, the impact of grid-following converters (GFL) on system stability continues to increase. The PI controller, as a crucial component in GFL, influences both the phase-locked loop (PLL) tracking accuracy and the performance of the GFL. During grid faults, the PI controller often experiences integral windup, leading to the accumulation of integral errors and deterioration of the performance of the GFL. In response to this issue, the anti-windup PI controller has been proposed and applied to the PLL of the GFL to improve its tracking accuracy. Initially, the grid-connected control system model for the GFL was established, and a structure employing the anti-windup PI controller for the GFL was introduced. Subsequently, an analysis of the influence of grid impedance on the anti-windup PI controller was conducted to determine the applicable scenarios for the anti-windup GFL. Finally, the accuracy of the theoretical analysis was verified through MATLAB simulations.
Study of blade moment calculation on variable geometry turbine adjusting mechanism
Authors: Zhong Yan , Chen Liangyu , Qin Yu , Yuan Fei , Wang Lei , Han Bing , Bai Haoxi , Li Zhuang , Lv Ming , Yan Zhuo
Published: August 2024

In recent years, the layout of rotary instructing leaves in mutable loop worm wheels has been a research hotspot. The rotary instructing leaves are subjected to the action of hyperthermal and nippy airstream and the influence of frictional force on the spin axis. For the rotary instructing leaves, the combined action of hyperthermal and nippy airstream generates an aerodynamical moment, while frictional force generates a frictional moment. When the rotary instructing leaves rotate, the aerodynamical moment and frictional moment constantly change as the angular motion of the blades. This research is rare, and there is no mature case for reference. The article applies fluid-structure coupled heat transfer and software programming to seek the blade moment. During the process of blade angular motion from -10° to +10°, the total moment of the blade earlier rises and afterward falls. When the blade angular position is -2°, the total moment runs to vertex 3.74489 N·m. Test data from the exploration laboratory have validated this conclusion. The maximum deviation compared to the test data of the exploration laboratory is 4.562%. The aerodynamical and frictional moments are momentous indicators for mutable loop worm wheel study. They can offer physical references for the mutable loop design of a turbo. The paper can also offer a new method for the blade moment calculation. This is important sense for the innovation of mutable cyclic worm wheels.
Predictive control of dual three-phase motor model based on harmonic suppression
Authors: Wang Xiangjun , Wei Haifeng
Published: August 2024

The traditional model predicts that the dual-three-phase motor is controlled by 12 synthesized virtual voltage vectors, and the suppression effect of harmonic current is average. In this paper, a harmonic suppression control method is proposed to realize the suppression of harmonic current, and then reduce the harmonic loss. At the same time, the calculation of the control quantity at the next time is carried out, the value function corresponding to each vector is calculated, and the optimal vector is determined by traversal optimization.
An open-circuit fault diagnosis method for PMSM drive system based on multi-branch 1D-CNN
Authors: Zhang Ye , Zhang Niaona , Zhang Yilei
Published: August 2024

In this paper, a fault diagnosis method based on multi-branch one-dimensional convolutional neural network (1D-CNN) is proposed for the open-circuit fault of the inverter IGBT and current sensor in permanent magnet synchronous motor (PMSM) drive system. Firstly, to avoid adding additional sensors, a three-phase current acts as a highly responsive signal for fault detection. Secondly, a multi-branch 1D-CNN diagnosis model is built to solve the complexity and uncertainty problems caused by traditional artificial feature extraction and selection. Then, the residual connection is introduced into the diagnostic model to alleviate the disappearance of the network gradient and accelerate the convergence speed. Finally, the three-phase current is directly input into the model for training and classification. The test results show that the method can identify the open-circuit fault of the IGBT and current sensor within the sample length of a fundamental cycle, and the accuracy rate is 99.84%. Compared with other traditional machine learning methods, it has been proven to have higher diagnostic accuracy and good anti-noise ability.
Study on the indoor mobile robot localization based on multi-sensor fusion
Authors: He Guobao , He Qianen
Published: August 2024

In recent years, mobile robots have found extensive application across diverse sectors including industry, agriculture, healthcare, and defense. However, relying solely on a single sensor for mobile robot localization presents several challenges, such as limited accuracy, divergence of localization errors over time, and susceptibility to obstruction from obstacles. This paper proposes an indoor mobile robot localization algorithm assisted by Ultra-Wideband (UWB). The algorithm begins by calculating the credibility of the Line-of-Sight (LOS) environment using UWB ranging measurements and predicted distances, enabling the identification of the Non-Line-of-Sight (NLOS) environment. Subsequently, ranging measurements affected by NLOS errors are compensated by using a complementary filter. Finally, these measurements are utilized for Extended Kalman Filter updates to achieve the best estimation of the mobile robot’s position. Field tests are conducted on a wheeled robot to validate the effectiveness and performance of the developed approach. Results show that the localization approach reduces the maximum localization error from 41 cm to 19 cm compared to UWB trilateration, achieving a 53.7% improvement. Even under a prolonged NLOS environment, the algorithm ensures that the localization error remains below 25 cm. The proposed method is of significant merit in solving the challenge of indoor mobile robot localization.
Classification of highly permeable distributed photovoltaic clusters considering comprehensive indicators
Authors: Zhang Xueyu , Lu Xiaojuan
Published: August 2024

A cluster partitioning method is proposed to address the issues of overvoltage and power flow reversal caused by the integration of high penetration distributed photovoltaic power sources into the distribution network, as well as the problems of long transmission distance, too many transformation devices, and immature technology brought about by centralized photovoltaic integration. This method considers both the system’s structural and functional characteristics. Firstly, the structural indicators adopt improved modularity indicators. In contrast, the functional indicators adopt cluster active and reactive power balance and node membership indicators, constructing an optimization model for the comprehensive indicator system. Secondly, to fully demonstrate the expression of the indicator system model, some improvements have been made to the traditional genetic algorithm, and the adjacency matrix has been established as the encoding method of the algorithm. Finally, an improved IEEE33 node and a 10kV actual distribution network in a certain area were analyzed and verified as examples. The simulation results show that the proposed cluster partitioning method improves power balance by more than 30% while ensuring minimal changes in modularity, indicating that the method has certain effectiveness in cluster partitioning.
Parametric design research of large-scale high-speed shaft system detection device based on solidworks
Authors: Xu Minggang , Ma Mingyue , Wang Zhe , Liu Zuhuang
Published: August 2024

In order to shorten the design cycle and facilitate the operation of design personnel, a parametric design system for large-scale high-speed shaft system detection devices was developed based on SolidWorks. The parametric design method was employed for the secondary development of SolidWorks, utilizing the software platforms SolidWorks 2018 and Microsoft Visual Studio 2019. The system was created using the VB.NET programming language, establishing a user-friendly human-machine interface window. This system achieved three-dimensional model parametric design, automatic generation of engineering drawings, and automated assembly. Finally, taking a custom model of a large-scale high-speed shaft system detection device as an example, the efficiency of the design system modeling and the intuitiveness of the design were validated.
Digital twin and hardware-in-the-loop based robotic arm modelling simulation
Authors: Zhang Xingmin , Dong Zhe , He Jiahuan
Published: August 2024

Aiming at a series of problems such as high testing cost, complex testing scenarios, and low testing efficiency in the testing of control algorithms for robotic arms, this paper proposes a method using semi-physical simulation technology combined with digital twin technology to solve this problem. Based on the V-model development process, the robotic arm control algorithm is designed, and the control effect is verified on the twin model. The extreme working condition test of the robotic arm controller is performed on the virtual test bench to achieve continuous algorithm optimization, verification, and iteration.
Design and simulation of low-ripple dual active bridge DC-DC converter
Authors: Luo Tuo , Jiang Pinqun , Huang Guoxian , Lin Dong
Published: August 2024

In addressing the issue of excessive high-frequency current ripple at the output port caused by high-frequency switching in traditional dual active bridge DC-DC converters, a low-ripple dual active bridge DC-DC converter was designed by replacing its switching devices with a half-bridge submodule. This converter constructs a decoupling loop for alternating and direct current components on the bridge arms, allowing the alternating components to form a loop between the bridge arms without entering the direct current port, thereby eliminating high-frequency current ripple at the direct current output port. Consequently, the filtering capacitors parallel to the direct current port can be omitted, while also suppressing direct current fault currents. Due to the inherent capacitance structure of the submodule switching devices, soft-switching characteristics are preserved, and conversion efficiency is not compromised. Simulation results based on a MATLAB/Simulink model of 750 V and 10 kW demonstrate that the ripple of this converter is less than 0.07%, a 90% reduction compared to traditional converters, and effectively suppresses fault currents, thereby enhancing system safety.
Scheduling twin-cluster tools for complete concurrent processing with wafer residence time constraints
Authors: Zhou Hao , Pan Chunrong
Published: August 2024

With the requirements of physical vapor deposition and chemical vapor deposition processes, twin-cluster tools are widely used in the current wafer fabrication. Cycle scheduling ensures that wafers have the same quality, however, twin-cluster tools involve resource coordination between two tools, which makes cycle scheduling more sophisticated. A steady-state cycle scheduling problem of twin-cluster tools with a complete concurrent processing module is studied, considering the wafer residency time constraints. First, a Petri net model is constructed to describe the process of twin-cluster tools under a steady state with the wafer residency time constraints and the complete concurrent processing module, and a control strategy is proposed to avoid the system deadlock. The sufficient conditions for the system to reach the highest efficiency are obtained by analyzing the workload of the processing module and the robot task, and an algorithm is developed to obtain the robot schedule. Finally, examples are verified about the effectiveness of the algorithms.
Research on ballistic protection characteristics of perforated plates made of different steel materials for 12.7 mm penetrator projectile
Authors: Shi Anshun , Hong Xiaowen , Han Hongwei , Xia Kailang , Fan Xuefei , Qin Chao , Sun Sujie
Published: August 2024

To compare the ballistic protection characteristics of perforated plates made of different steel materials against 12.7 mm perforating ammunition, the ballistic gun, light curtain velocity measurement system, and high-speed camera were used to study its ballistic performance, and the ballistic protection, perforated plate damage area, core fracture and core deflection characteristics of perforated plates made of different armor steel materials were compared. The results show that the ballistic protection performance of C-2 and H-1 perforated plates is better than that of C-1 and C-3 perforated plates, the protection performance of C-1 and C-3 is equivalent, and the protection coefficient of H-1 can reach or even exceed that of C-2. The hole damage area of an H-1 perforated plate is larger than that of a circular perforated plate, and the number of bullet core fractures is more, but its crack arrest performance is poor. The damage area of a single interconnection hole in perforated plates of different armor steel materials meets the linear relationship, and its linear slope can characterize the degree of hole loss. The damage of a single interconnection hole with hexagonal holes is greater than that of perforated plates with circular holes. At the same time, the projectile deflection angle of perforated plates made of different armor steel materials also conforms to the linear relationship, and the fitting linear slope can measure the degree of core deflection. The higher the hardness of perforated plates with circular holes, the greater the core deflection, while the degree of core deflection of hexagonal holes is greater than that of perforated plates with circular holes.
Dynamic characteristics of dry-type transmission tower under wind-sand load
Authors: Li Fule , Yuan Binxia , Dai Jingjing
Published: August 2024

The desertification in Northwest China is serious, and the transmission tower has been affected by dust storms. To investigate the harm of wind-sand load on transmission towers, the paper takes the dry-type transmission tower as the research object and uses ANSYS software to study the dynamic characteristics. The wind and sand loads are coupled and su-perimposed by MATLAB software. The dynamic characteristics of transmission towers under different wind load and sand load conditions are studied. The results show that the horizontal offset and the overall stress of the tower will increase under wind-sand coupling load, which makes the tower stability worse.
The effect of the propellant type size on combustion performance of the multi-nitro ester propellant
Authors: Wang Tao , Chen Ling , He Weidong
Published: August 2024

To study the effect of propellant size on the combustion performance of the propellant, the combustion performance of three propellant types and their different ratio of inner perforation to diameter were studied by using the combustion experiment and data processing method of multi-nitro ester propellant as the research object. The results showed that within the test drug size range, under different initial temperatures and filling density conditions, the larger the ratio of charge length to the diameter of single-perf, 7-perf, and 19-perf propellant is, the larger the burning rate will be under the same pressure at the initial stage of combustion. The larger the length-to-diameter ratio of 7-perf and 19-perf propellants of the same type is, the better the gradual combustion will be, and the less influence there will be on single-perf propellants. The loading density has a certain effect on the constant volume combustion performance of the propellant: the higher the loading density is, the lower the combustion rate will be, which is because the erosion combustion phenomenon of the initial combustion of the propellant decreases with the increase of the loading density.
Investigation of oxide inclusion films in cast superalloy impeller
Authors: Zhang Lihui , Chen Jun , Xing Weijie , Wu Wenjin , Guo Fengwei , Zhang Qiang , Liu Changkui
Published: August 2024

Oxide inclusions are commonly found in casting alloys. During vacuum investment casting of polycrystalline nickel-based superalloy, various forms of oxide inclusions can be observed, including membrane-like inclusions. These oxide inclusion films can significantly reduce the mechanical properties of nickel-based superalloys. A cast superalloy impeller that fractured due to internal oxide inclusion films was analyzed in this article. The objective of this article is to analyze the morphology and composition of oxide inclusion films and investigate their formation mechanisms. This article uses a scanning electron microscope and transmission electron microscope to characterize oxide inclusion film samples. The results show that the oxide inclusions are composed of film-like alumina, magnesium-aluminium spinel, and magnesia particles encapsulated by magnesium-aluminium spinel films. The oxide inclusion films are formed through a reaction between the liquid metal melt and the magnesia crucible. These oxide films are then floating into the nickel matrix through the scouring of the liquid metal melt and become internal inclusions.
Study on the properties of solidified materials of municipal waste incineration ash cementitious materials
Authors: Wang Ke , Weng Zhan , Zhang Jinghui , Du Jiahui , Li Mingfu , Liu Tiejun
Published: August 2024

MSWI FA needs to be treated effectively to prevent harmful effects on the environment and human beings. The use of different ratios of cementitious materials for the solidification of fly ash provides innovative ideas for the environmentally friendly treatment of MSWI FA. In this study, some raw materials were used to solidify fly ash, and it was revealed that the incorporation of appropriate concentrations of fly ash (20 and 30%) could improve the compressive strength, fluidity, pore structure, and rheological properties of the solidified materials, and reduce the setting time, the bleeding rate, and inhibit the phenomenon of drying shrinkage of the solidified materials. However, when the content of MSWI FA exceeded 40%, the performance of the solidified material decreased significantly due to the poor volcanic ash activity and the high water absorption capacity of MSWI FA.
Effect of process parameters on the temperature field of laser sintering of nylon PA2200 powder
Authors: Liu Kai
Published: August 2024

Utilizing the ANSYS finite element analysis software, a three-dimensional heat transfer finite element model for the SLS forming process of nylon PA2200 powder was constructed. The APDL parametric language was employed to control the movement of the Gaussian heat source, enabling numerical simulations of the temperature field during the single-layer, single-pass sintering process. Through numerical simulation analysis, the varying pattern of the melting width was derived. Based on the optimal overlap rate required for satisfactory SLS forming quality, the optimal parameter combination for nylon PA2200 powder sintering was determined to be a laser power of 40 W, a scanning speed of 5000 mm/s, a layer thickness of 0.12 mm, and a preheating temperature of 165°C. These findings provide valuable insights for optimizing the SLS process and enhancing the quality of the final sintering parts.
DLP 3D printing of high-resolution, temperature-responsive hydrogel microneedles with rapid customization capability
Authors: Zhou Xinmeng , Liu Huan , Li Huanjun
Published: August 2024

Hydrogel microneedles (MNs) are emerging as versatile transdermal drug delivery platforms for the treatment of various diseases. However, their conventional preparation method is plagued by a complex process, time-consuming nature, and low resolution. To address these challenges, we present a novel method for preparing temperature-responsive hydrogel MNs using a Digital Light Processing (DLP) strategy. The printed NIPAM-AA-AM hydrogel MNs can be rapidly customized (within 1 hour) into various shapes and heights with high resolution. The mechanical tests and H&E staining validate the ability of the MNs to penetrate the skin. In addition, the temperature-responsive drug delivery of the MNs was demonstrated through experiments and COSMOL simulations. Notably, these biocompatible microneedles showed non-toxicity in NIH-3T3 cells and low hemolysis rates, thereby indicating promising prospects for safe in vivo utilization. This study offers a simple and rapid alternative for the fabrication of smart responsive microneedles, opening up new avenues in personalized and efficient transdermal drug delivery strategies.
Preparation and performance verification of calcium silicate composite electrical fireproof materials
Authors: Wang Yin , Wang Yu , Yang Dedong , Fu Guanggang , Zheng Chong , Kong Fanfang , Nie Jingkai , Ji Jun
Published: August 2024

The wall bushings of the converter transformer are often sealed with rock wool for fire prevention, but the fire resistance is not enough for hydrocarbon fire for 1 h, which leads to frequent fires in the converter station. In this paper, calcium silicate-bound vermiculite lightweight materials with a density of less than 900 kg/m3 were prepared by static hydrothermal autoclaving reaction with calcium silicate-rich powder as raw material, expanded vermiculite as aggregate, and fiber reinforced. The effect of material ratio on bulk density, strength, and high temperature resistance was discussed. The results show that the micropore structure developed in the binding phase is mainly composed of Tobe mullite and xonotlite, and the interlamellar pores between Tobe mullite and vermiculite contributed to the high porosity of the material. At the same time, the combination phase and vermiculite interpenetrating combination structure, so that the material has a high strength. Low shrinkage and low thermal conductivity characteristics of the composite under electric fire.
Performance analysis of motorized axles
Authors: Yan Yan , Hang Peng , Cao Liangqiang , Huang Tao , Duan Jingjing , Wu Yahu
Published: August 2024

As the electric wheel requires the integration of the hub motor and brake within the hub, the integration scheme and structural parameters of each component in the electric wheel play a crucial role in the coordination with the electric wheel and its running performance. The finite element analysis is conducted on the axle of the electric wheel to judge whether the structural parameters meet the performance requirements, providing a basis for the axle design of the electric wheel. This will have a decisive role in the safety performance and life of the car, effectively improving the working stability of the electric wheel.
Research on the failure mechanism of non-metallic oil pipeline flange
Authors: Weng Yu , Li Dejun , Jiang Shuxuan , Yang Shuang , Wu Gang , Deng Zhian
Published: August 2024

Fiberglass flanges are gradually being applied in oil field mixed transportation pipelines due to their advantages such as corrosion resistance and easy forming. However, at the same time, the anisotropy and local discontinuity are present in glass fiber components. Starting from the discovery of cracking, leakage, and other issues in the fiberglass flange of a certain oilfield sewage export pipeline, a combination of experimental research and numerical analysis is used to study the on-site fiberglass flange joint. Considering the internal pressure, bending moment, bolt load, and other loads in actual operating conditions, mechanical performance tests are conducted on the flange substrate, and the mechanical properties and damage conditions are obtained. A finite element model including pipeline gasket flange is constructed, and the flange damage under preloading, operation, external bending moment, and other operating conditions is analyzed based on the nonlinear Hashin failure criterion and the Tserpes sudden stiffness degradation model. It is found that bolt holes are more prone to large-scale failure damage due to stress concentration. As the external bending moment increases, it will simultaneously reduce the gasket compressive stress and cause flange surface failure and damage. According to research, it is recommended that the pre-tightening force of bolts during pipeline operation should not exceed 400000 N, and the bending moment generated by factors such as wind load and soil load should not exceed 200 N·m.
Analysis of isothermal elastohydrodynamic lubrication on the rough surface of a new type of trident universal joint
Authors: Xu Yutian , Yang Yan , Wang Guowei , Niu Jiahong
Published: August 2024

Taking the roughness into consideration, this chapter mainly studies the isothermal elastohydrodynamic lubrication between the slider and the balls in the new three-pronged universal joint and gives the relevant equations under isothermal conditions. The Reynolds equation is the primary tool for iteration, and Matlab is used for programming and plotting. In the simulation experiment, the roughness is given as 0. Then the amplitude and frequency of the roughness are varied to observe the oil film thickness and pressure respectively. With the increase of surface fluctuation, the film thickness in the center of the contact range becomes thicker, the pressure changes more and more sharply, and the peak value of secondary pressure is basically unchanged. As the frequency of the sinusoidal roughness increases, the film thickness in the center of the contact area becomes thinner as the frequency of roughness enhances, the fluctuations become more and more frequent, the pressure fluctuates around the original curve more and more often, and the amplitude becomes larger and larger.
Multi-material optimal design of miura origami folds based on genetic algorithm
Authors: Jiang Yahong , Zhou Jinyu , Xue Yaping , Hu Haotian
Published: August 2024

Based on the theoretical model of Miura origami, this paper uses Python and Abaqus software to optimize the design of multi-material positions at the crease of Miura origami by using a genetic algorithm. Firstly, the parametric modeling of Miura origami is carried out; then linear cell meshing is performed at the origami crease, and polylactic acid (PLA) and thermoplastic polyurethane (TPU) are selected as the optimized materials; finally, the multi-material position distribution is optimized by the genetic algorithm according to the target value, to search for the optimal distribution of the materials. Therefore, the angular displacement of the Miura origami model under the thermal drive meets the desired target value. This method solves the problem of finding the optimal multi-material distribution design under the target deformation and provides important ideas and references for the design of space expandable mechanisms simultaneously.
Effect of boundary layer thickness and dimensionless wall distance y+ on numerical simulation of heat pipes
Authors: Zhao Wenjie , Deng Jiajia , Xue Dawen , Xu Lin
Published: August 2024

To consider the sway of boundary layer thickness and dimensionless wall distance y+ on the numerical simulation results of the thermo tube, taking the straight thermo tube as an example, using the continuity equation, momentum equation, energy equation, and turbulence model equation as the controlling equations, and adopting the finite volume method for the spatial discretization, the numerical simulation study of the heat pipe is carried out by controlling the changes of boundary layer thickness and dimensionless wall distance y+. Numerical simulation studies show that the boundary layer thickness and y+ have a large effect on the numerical simulation of heat pipes. Reasonably setting these two parameters within a certain range can improve the accuracy of heat pipe numerical calculations, and the results of the study can provide a reference for the security analysis of thermo tube reaction vessels.
Influence of pre-tightening force on bearing capacity of composite cylinder
Authors: Yang Bo
Published: August 2024

For investigating the effect of preload on the bearing capacity of the composite hydrogen storage cylinders, the FEM of fiber full-wound aluminum liner cylinder is established by ABAQUS software. Stress calculation was carried out with and without preload. The results show that under working pressure, the application of pre-tightening pressure can cause the reduction of lining stress level and increase fiber layer stress, and the application of pre-tightening pressure can improve the stress distribution of the lining and fiber layer.
Study on the effect of permanent magnet guideway surface defect on the mechanical properties of multi-surface high-temperature superconducting permanent magnet levitation system with halbach-type guideway
Authors: Peng Jiahao , Zhao Xianfeng , Guo Yulong
Published: August 2024

The purpose of this study is to discuss the effect of defects on the mechanical properties of halbach-type guideway surfaces in high-temperature superconducting permanent magnetic levitation systems with single-surface superconductor distribution versus multi-surface superconductor distribution. The study models the high-temperature superconducting permanent magnetic levitation system based on Maxwell’s system of equations and compares it with the experimental data to obtain the variation curve of the levitation force of the levitation system under ideal conditions. Through numerical simulation and data analysis, it is found that the levitation force and guiding force of the high-temperature superconducting permanent magnetic levitation system will regularly decrease with the expansion of the defects, which will lead to the reduction of the system’s load-carrying capacity and stability. These findings are of great significance for the design and application of high-temperature superconducting magnetic levitation systems, and provide theoretical support and technical guidance for the practical application of high-temperature superconducting magnetic levitation systems.
Study on the influence of hole shapes on the fluid and mechanical properties of perforated honeycomb sandwich structures
Authors: Xiao Pengfei , Zhou Chunping , Luo Yunfeng
Published: August 2024

Due to the high load and heat transfer capacity, porous honeycomb sandwich structures are widely in engineering. However, in functional requirements, mass and heat transfer should be realized which results and perforated holes being applied in sandwich structures. The shape of the holes plays a crucial role in further improving the load-bearing and flow-resistance performance of the structure. In this study, the influence of hole shape on the flow resistance, permeability, and mechanical properties of perforated honeycomb sandwich structures are systematically studied. Five different hole shapes with the same area are considered, and the flow resistance, permeability, and maximum Mises stress of the perforated honeycomb sandwich structure under the five conditions are calculated. The results show that the hole shape does have a significant influence on the flow resistance, permeability, and mechanical properties of the structure, and especially, it is especially found that the circular structure has the lowest flow resistance and the rectangular structure has the highest load-bearing capacity.
Simulation and analysis for residual stresses in anode-supported flat-plate solid oxide fuel cells for ships
Authors: Li Zhaoqiang , Wang Lingling , Yang Haijun , Ji Wendong , Zhang Yushan , Lu Baocheng
Published: August 2024

For investigating the distribution of residual stress in marine SOFC, this paper establishes a two-dimensional axisymmetric model of a SOFC single cell to simulate the temperature change in the cell preparation process, and the results find that: The residual stresses in the cell are mainly concentrated at the bond where the anode support layer and the electrolyte layer combine. At the outermost intersection, there is a maximum stress of 184.43 MPa. Meanwhile, we analyze the interaction of component thickness parameters for residual stresses, and the simulation results show that: The largest first principal stress of the assembly shows a straight-line decreasing trend when the thickness of the anode support layer increases; However, in the same scenario for the electrolyte layer, the maximum stress increases rapidly in the beginning and then increases slowly until it does not increase anymore; There is no effect of the variation in thickness parameters for the cathode and isolation layers on the maximum first principal stress of the module.
Study on the relationship between reflectivity and thickness of radar-absorbing material
Authors: He Song , Hu Jun , Chen Jinsong , Xi Qiushi
Published: August 2024

Radar-absorbing materials (RAM) have been widely used in civilian areas for electromagnetic interference shielding and in the defense sector for radar wave stealth. The thickness of radar-absorbing materials is one of the important parameters affecting their performance. This paper analyzes the relationship between the absorbing performance of radar-absorbing materials and thickness based on transmission line theory. Through theoretical derivation and simulation verification, the concepts of optimal usage thickness and cutoff thickness of materials are derived. The research results have important guiding significance for the application and optimization design of radar-absorbing materials.
Study on the effect of polypropylene fiber shape and admixture on the mechanical properties of concrete
Authors: Li Jiuyang , Fan Xinmei , Zhu Yuepeng , Luo Jingwei , Wang Xiaoyu , Guo Jinpeng , Li Fan , Zhang Zicheng
Published: August 2024

The effect of three different shapes of PPF on the mechanical properties of concrete at different dosages was investigated. Cubic compressive ability test, split tensile ability test, and flexural ability test were conducted on polypropylene fiber concrete to analyze the effect of PPF on compressive ability, tensile compression ratio, and flexural compression ratio. The study shows that as the shape and admixture of polypropylene fibers have an impact on the compressive strength of concrete, monofilament-type polypropylene fibers will have the worst effect on the enhancement of the effect when the choice of a mixture of 0.90% of embossed polypropylene fibers on the role of the compressive ability of the concrete has the best effect. The concrete tensile compression ratio is mainly affected by the mixing amount of polypropylene fibers, and the main factors affect the concrete folding compression ratio of the polypropylene fibers of the shape of the main factors.
Stress analysis and calculation of the inner anchor structure of pressure-type anchor
Authors: Ma Jian , Zhang Qi , Dan Hanbo , Pan Feng , Xu Gang , Guo Yong , Lü Qing
Published: August 2024

The pressure-type anchor transfers the load to the grouting body via the inner anchor structure at its bottom when bearing the uplift loads. In order to design the inner anchor structure reasonably, the elastic thin plate theory is used to analyze the inner anchor structure under uniformly distributed loads. Based on material properties, the calculation method and the recommended values for the size parameters of the inner anchor structure are given. A finite element model of the inner anchor structure is established with which the rationality of the proposed method and the recommended parametric values are verified by analyzing the stress situation of the internal anchor structure under ultimate load.