bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kalman-based estimation of loading conditions from ultrasonic guided wave measurements
Authors: Dalmora André , Imperiale Alexandre , Imperiale Sébastien , Moireau Philippe 
Published: September 2024

Abstract
Ultrasonic guided wave-based structural health monitoring (SHM) of structures can be perturbed by environmental and operations conditions (EOCs) that alter wave propagation. In this work, we present an estimation procedure to reconstruct an EOC-free baseline of the structure from the only available Ultrasonic guided wave measurements. This procedure could typically be used as a prior step to increase the robustness of a more general ultrasonic imaging algorithm or SHM process dedicated to flaw detection. Our approach is model-based, i.e. we use a precise modeling of the wave propagation altered by structure loading conditions. This model is coupled with the acquired data through a data assimilation procedure to estimate the deformation caused by the unknown loading conditions. From a methodological point of view, our approach is original since we have proposed an iterated reduced-order unscented Kalman strategy, which we justify as an alternative to a Levenberg–Marquardt strategy for minimizing the non quadratic least-squares estimation criteria. Therefore, from a data assimilation perspective, we provide a quasi-sequential strategy that can valuably replace more classical variational approaches. Indeed, our resulting algorithm proves to be computationally very effective, allowing us to successfully apply our strategy to realistic 3D industrial SHM configurations.
Design of bi-axial piezoelectric MEMS micro mirror with gimbal actuator for dynamic decoupling
Authors: Yang Hui-Ming , Hsu Chih-Chen , Lin Po-Chun , Lin Hung-Yu , Chen Si-Han , Cheng Hao-Chien , Fang Weileun 
Published: September 2024

Abstract
This study presents a novel structural design of a bi-axial piezoelectric micro-electro-mechanical-systems scanning mirror aimed at preventing the dynamic coupling between the two scanning axes and avoiding distortion of the scanning pattern. In the proposed design, the gimbal actuator, constrained by torsional springs at both ends, not only serves as the torque generation component for the actuation of one axis but also acts as a pivot to prevent structural interference between the two axes during scanning. This approach achieves the advantages of decoupling and compactness simultaneously. Simulations indicate that the gimbal actuator experiences very small displacement during y-axis actuation, thus realizing the dynamic decoupling from the x-axis scanning unit. To evaluate the proposed designs, fabrication processes were adopted on a silicon-on-insulator wafer with a lead zirconium titanate film. The miniaturized scanners, featuring a mirror with a 1.2 mm diameter, were realized on a compact 5 × 5 mm2 chip. Measurements indicate that the resonant frequencies of x-axis and y-axis scanning are 2.69 kHz and 4.29 kHz, respectively, and the optical scanning angles reach 33° and 21° under an 8 Vpp driving voltage. Additionally, measurements show that the displacement ratio between the central mirror and the gimbal actuator can reach up to 17 during y-axis actuation, verifying the concept of dynamic decoupling. The bi-axial Lissajous scanning pattern with straight edges also demonstrates the effective decoupling by the proposed gimbal actuator design.
Oxidative stress-modifying effects of TiO2 nanoparticles with varying content of Ti3+(Ti2+) ions
Authors: Kireev Viktor , Bespalova Iryna , Prokopiuk Volodymyr , Maksimchuk Pavel , Hubenko Kateryna , Grygorova Ganna , Demchenko Lesya , Onishchenko Anatolii , Tryfonyuk Liliya , Tomchuk Oleksandr , Tkachenko Anton , Yefimova Svitlana 
Published: September 2024

Abstract
Nanoparticles (NPs) with reactive oxygen species (ROS)-regulating ability have recently attracted great attention as promising agents for nanomedicine. In the present study, we have analyzed the effects of TiO2 defect structure related to the presence of stoichiometric (Ti4+) and non-stoichiometric (Ti3+ and Ti2+) titanium ions in the crystal lattice and TiO2 NPs aggregation ability on H2O2- and tert-butyl hydroperoxide (tBOOH)-induced ROS production in L929 cells. Synthesized TiO2-A, TiO2-B, and TiO2-C NPs with varying Ti3+(Ti2+) content were characterized by x-ray powder diffraction, transmission electron microscopy, small-angle x-ray scattering, x-ray photoelectron spectroscopy, and optical spectroscopy methods. Given the role of ROS-mediated toxicity for metal oxide NPs, L929 cell viability and changes in the intracellular ROS levels in H2O2- and tBOOH-treated L929 cells incubated with TiO2 NPs have been evaluated. Our research shows that both the amount of non-stoichiometric Ti3+ and Ti2+ ions in the crystal lattice of TiO2 NPs and NPs aggregative behavior affect their catalytic activity, in particular, H2O2 decomposition and, consequently, the efficiency of aggravating H2O2- and tBOOH-induced oxidative damage to L929 cells. TiO2-A NPs reveal the strongest H2O2 decomposition activity aligning with their less pronounced additional effects on H2O2-treated L929 cells due to the highest amount of Ti3+(Ti2+) ions. TiO2-C NPs with smaller amounts of Ti3+ ions and a tendency to aggregate in water solutions show lower antioxidant activity and, consequently, some elevation of the level of ROS in H2O2/tBOOH-treated L929 cells. Our findings suggest that synthesized TiO2 NPs capable of enhancing ROS generation at concentrations non-toxic for normal cells, which should be further investigated to assess their possible application in nanomedicine as ROS-regulating pharmaceutical agents.
On formal series solutions to 4th-order quadratic homogeneous differential equations and their convergence
Authors: Hosoi Tatsuya 
Published: September 2024

Abstract
It is known that all τ functions of the Painlevé equations satisfy the fourth-order quadratic differential equation. Among them, for the III, V, and VI equations, it is possible to express the formal series solutions combinatorially by using conformal blocks. In this paper, we show the convergence of the formal series, including the solutions of more general equations. The convergence of the conformal block function also follows in the case c = 1 by the absolute convergence of τ series, since it is a partial sum of the τ series. We also characterized the form of a homogeneous quadratic equation with a series solution similar to the tau functions of the Painlevé equations.
Phase-change ultrasound contrast agents for proton range verification: towards an in vivo application
Authors: Carlier Bram , Heymans Sophie V , Collado-Lara Gonzalo , Musetta Luigi , Ingram Marcus , Toumia Yosra , Paradossi Gaio , Vos Hendrik J , Roskams Tania , D’hooge Jan , Van Den Abeele Koen , Sterpin Edmond , Himmelreich Uwe 
Published: September 2024

Abstract

Objective. In proton therapy, range uncertainties prevent optimal benefit from the superior depth-dose characteristics of proton beams over conventional photon-based radiotherapy. To reduce these uncertainties we recently proposed the use of phase-change ultrasound contrast agents as an affordable and effective range verification tool. In particular, superheated nanodroplets can convert into echogenic microbubbles upon proton irradiation, whereby the resulting ultrasound contrast relates to the proton range with high reproducibility. Here, we provide a first in vivo proof-of-concept of this technology. Approach. First, the in vitro biocompatibility of radiation-sensitive poly(vinyl alcohol) perfluorobutane nanodroplets was investigated using several colorimetric assays. Then, in vivo ultrasound contrast was characterized using acoustic droplet vaporization (ADV) and later using proton beam irradiations at varying energies (49.7 MeV and 62 MeV) in healthy Sprague Dawley rats. A preliminary evaluation of the in vivo biocompatibility was performed using ADV and a combination of physiology monitoring and histology. Main results. Nanodroplets were non-toxic over a wide concentration range (<1 mM). In healthy rats, intravenously injected nanodroplets primarily accumulated in the organs of the reticuloendothelial system, where the lifetime of the generated ultrasound contrast (<30 min) was compatible with a typical radiotherapy fraction (<5 min). Spontaneous droplet vaporization did not result in significant background signals. Online ultrasound imaging of the liver of droplet-injected rats demonstrated an energy-dependent proton response, which can be tuned by varying the nanodroplet concentration. However, caution is warranted when deciding on the exact nanodroplet dose regimen as a mild physiological response (drop in cardiac rate, granuloma formation) was observed after ADV. Significance. These findings underline the potential of phase-change ultrasound contrast agents for in vivo proton range verification and provide the next step towards eventual clinical applications.
Effect of Cr3C2 on wear behavior of Ni45 laser cladding coating
Authors: Liang Limeng , Feng Dawei , Ma Shuli , Zhang Jie , Ding Guohua 
Published: September 2024

Abstract
To improve the performance of engineering components subjected to severe wear, temperature fluctuations, and corrosive conditions in industries such as chemical, aerospace, and power plants, Ni45-based coatings with varying Cr3C2 contents (0%, 10%, 20%, and 30%) were applied to a 45-steel surface. The microstructure of these coatings was examined by scanning electron microscopy (SEM), and their wear resistance was compared. As the Cr3C2 content in the cladding layer increased, there was a notable improvement in its wear resistance. Specifically, when the Cr3C2 content reached 30% by weight, the wear resistance of the cladding layer exceeded that of the GCr15 steel. Furthermore, the adhesive wear between the cladding layer and the GCr15 steel diminished, while the oxidation wear of the GCr15 steel intensified. This study aims to elucidate the primary wear mechanisms of the Cr3C2/Ni45 cladding layer and offer valuable insight into improving the durability of engineering components in harsh environments.
Effect of Ag coatings prepared by magnetron sputtering on the wear properties of Ti6Al4V alloy
Authors: Huang Xinyu , Rong Wenjuan , Wang Jialin 
Published: September 2024

Abstract
Ag coatings were prepared on the surface of Ti6Al4V alloy by magnetron sputtering technique, and the effects of different Ag target power and sputtering time on the coating properties were investigated. The coating thickness was firstly measured by a step meter, and then the coatings obtained under different parameters were characterized by Vickers hardness tester, scratch tester, and friction wear tester. The variation in the furnace temperature had a significant effect on the hardness of the coatings: the coating thickness increased slightly with increasing temperature, but the increase was not dramatical. The Vickers hardness of the coatings showed a tendency to increase and then decrease with increasing temperature, reaching a peak at 150 °C. The hardness of the coatings was found to increase with increasing temperature and then decrease with increasing temperature. Scratch tests further showed that the coatings prepared in the range of 150 °C to 180 °C exhibited superior bond strength with the substrate. The wear morphology of the coatings showed that the coatings prepared at 150 °C had the best wear resistance. At this temperature, the flaking of the coating due to adhesive wear was significantly reduced, and the depth of scratches due to abrasive wear was also reduced. The variation of the Ag target power also had a significant effect on the hardness of the coatings. As the target power increases, the coating thickness increases significantly, and the Vickers hardness increases and then decreases, reaching a maximum at 12 W. The coatings prepared at 10 W show better performance in terms of scratch and wear patterns. These experimental results provide strong data support for the subsequent preparation of Ti6Al4V joint prostheses.
Different temperature-dependent fluorescence properties of CsPbBr3 nanorods and nanowires
Authors: Chen Fengjiao , Li Liting , Shen Xiong , Zhang Jing , Ma Siyu , Wang Yue , An Limin 
Published: September 2024

Abstract
The morphology of totally inorganic metal halide perovskites has a certain influence on their optoelectronic properties. In this study, one-dimensional CsPbBr3 nanorods (NRs) and nanowires (NWs) were arranged utilizing a boiling injection strategy. By controlling the processing time, NRs with a length of roughly 63 nm and NWs with a length of 300 nm were obtained, and it was found that the nanowires were grown from the nanorods. Temperature-dependent photoluminescence (PL) measurements were conducted on CsPbBr3 NRs and NWs, and NRs exhibit a more stable excitonic state at high temperatures (>240 K). This study provides a method to change the morphology of one-dimensional metal halide perovskite nanomaterials without doping, further promoting the application of one-dimensional all-inorganic perovskite materials in the field of optoelectronics.
Research on moisture absorption characterization of wound composites based on surface concentration modified model
Authors: Yang Zilong , Hu Yuxia , Li Wusheng , Yang Fujiang 
Published: September 2024

Abstract
Four groups of hygroscopic experiments of T700/epoxy composite wound rings at temperatures and humidities of 45°C/60%, 45°C/90%, 70°C/60%, and 70°C/90% were completed in order to study the moisture absorption characterization. Surface concentration correction models characterized by different types of functions such as linear, quadratic, sinusoidal, exponential, and others were proposed to establish a “three-stage” moisture absorption model, in which the initial stage was smooth, the middle stage grew rapidly, and the later stage tended to equilibrium. The theoretically predicted hygroscopic curves derived from quadratic and exponential functions were in good agreement with the experimental data, which revealed the difference in the moisture absorption characterization between the wound rings with high fiber volume and that of the laminates and fabrics and provided a basis for the prediction of the mechanical degradation and life of the wound composites in hygrothermal environments.
Influence of secondary peak temperature on simulated ICCGHAZ microstructure and toughness of high-strength low-alloy steels
Authors: Bao Liangliang , Xu Yanhong , Zhang Xinming , Jiang Jun 
Published: September 2024

Abstract
The ICCGHAZ specimens of laser-arc hybrid welding under various secondary peak temperatures were prepared using welding thermal simulation technology. Investigations were conducted into how the toughness and microstructure of the simulated ICCGHAZ specimens were correlated with the secondary peak temperature. Results showed that the size, distribution, and morphology of the M-A constituents in the ICCGHAZ specimens were primarily influenced by the secondary peak temperature. With this temperature at 760 °C, the blocky M-A constituents mostly aggregated into chains along the grain boundaries. As the secondary peak temperature reached 800 °C, while the blocky M-A constituents typically stayed close to the grain boundaries, the necklace M-A constituents began dispersing. The former austenite grain boundaries vanished as the M-A constituents migrated outward when the temperature further rose to 840 °C. At secondary peak temperatures of 760 °C and 800 °C, the volume proportion of the M-A constituents was 2.9% and 3.2%, respectively. In comparison, the volume fraction rapidly decreased to 0.9% at 840 °C. The size of the M-A constituents shrank as the secondary peak temperature rose, whereas the crack initiation energy Ei, crack propagation energy Ep, and impact energy Et increased. The toughness of the ICCGHAZ specimen was diminished because of the grain boundary necklace distribution characterization and the large size of the M-A constituents.
Application of instrument indentation test for residual stress characterization of 5083 aluminium alloy
Authors: Du Zhuotong , Zhao Rutao , Gao Chen , Chen Pei , Xu Kuilong 
Published: September 2024

Abstract
An abnormal cracking phenomenon occurred at the corner of a ventilation window on the 5083 aluminum alloy wallboard used in certain transportation equipment. The residual stresses of the wallboard were measured using an instrumented indentation test. Initially, stress loading was applied to the 5083 specimens using a residual stress loading device to verify the effectiveness of the instrument indentation test (IIT) for testing the residual stresses of 5083 aluminum alloy. Subsequently, IIT was conducted under static conditions at the serving site of the equipment, and the working stresses under dynamic conditions were detected using a strain monitor. The results indicate that the total tensile stress at the uncracked corner of the ventilation window has exceeded the 5083 yield strength, so excessive tensile stress is the main cause of the abnormal cracking of the wallboard.
Molecular dynamics simulation of irradiation damage accumulation in α-Fe and model alloy FeMn1.4Ni0.7
Authors: Zhang Wenqing , Wu Jiaxin , Zhou Feng , Chen Jinhong , Zhu Fei , Song Ligang , Ma Xianfeng 
Published: September 2024

Abstract
The neutron irradiation of RPV steel leads to the generation of defects and further degrades the mechanical properties. MD simulation was used to study the accumulated damage of α-Fe and model alloy FeMn1.4Ni0.7 at room temperature. Two methods of introducing PKA, i.e., concentrated irradiation and uniform irradiation, were performed. The simulation results showed that concentrated irradiation is beneficial for the clustering of vacancies and the formation of vacancy DLs <100>. All the types of interstitial DLs are 1/2 < 111 >, and all the types of vacancy DLs are < 100 >. The addition of Mn and Ni restrained the clustering of interstitials under uniform irradiation conditions.
Outer spiral drill rod lunar soil sampling resistance moment simulation study
Authors: Li Dehui , Luo Haitao , Li Yuxin , Dong Yuming 
Published: September 2024

Abstract
The task of unmanned automated sampling of China’s lunar exploration is to bring back lunar soil samples with a certain depth, and sampling of external auger drill pipe is the best way. The power and moment size of the lunar surface is limited, so a special design is required. In this paper, a unique structural model of a double-auger drilling tool is designed. It is a movement analysis of lunar soil and drill pipe. We use simulated lunar soil simulations and experiments. The Hertz-Mindlin slip-free model in the discrete element software EDEM was used for numerical simulation. Given the disadvantage of the large amount of computation of discrete elements, the “embedding simulation method” proposed in this paper reduces the amount of computation. When drilling 0.4m and 1m under lunar and earth gravity, the magnitude and influence of drill pipe rotation and vertical velocity on the drag moment were analyzed. We provide the relevant technical parameters of the real unmanned drilling activities on the lunar surface. Through simulation, the rationality parameters of several groups of drill pipe drilling are obtained to ensure the smooth progress of drilling.
Theoretical investigation of Cu influence on the stability characteristics of T-phase in crossover alloys
Authors: Xue Boyu , Xiao Wei , Li Xiwu , Gao Guanjun , Li Xiaowu , Yan Hongwei , Yan Lizhen , Zhang Yongan , Xiong Baiqing 
Published: September 2024

Abstract
In crossover Al-Mg-Zn alloys, the T-phase (Mg32(Al, Zn)49) is crucial for reinforcement. The critical nucleation size of the precipitated T-phase is notably reduced by Cu addition, as well as the activation energy. There is a lack of theoretical research on the influence of Cu elements on the stability of T-phases and mechanical properties. In this work, we systematically investigate the influence of varying Cu concentration on the T-phases by examining their stability, mechanical properties, and electronic structure characteristics through first-principles calculations. The findings reveal that the T-phase maintains lattice stability within the 0 to 5% Cu content range, with a linear decrease in the lattice parameter and formation energy (–0.16 ~ –0.15 eV/atom). Additionally, there is an observable positive correlation trend between the elastic moduli (B, E, and G) of the T-type phase and the Cu content. It is shown that the T-phase exhibits inherent ductility. Analysis based on Pugh’s criterion and Poisson’s ratio indicates a reduction in the ductility with increasing Cu content in the T-phase. This work theoretically validates the previous experimental observations and reveals the impacts of Cu concentration on the T-phase.
Multipeak ultraviolet lasing based on F-P mode from in-situ ZnO nanowire
Authors: Zhang Ying , Liu Ruibin 
Published: September 2024

Abstract
High-quality ultraviolet singlemode and multimode lasing from zinc oxide nanowires are highly desirable. In this paper, we achieve high-Q lasing oscillation in vertically grown Zinc oxide (ZnO) microwires. The broad gain range reaches 13 lasing modes under high-energy excitation. We observe multiple peak emissions from the Fabry-Perot (F-P) lasing mode. In contrast, nanorod arrays with low aspect ratios exhibit amplified spontaneous emission (ASE) due to significant diffraction losses. Our work demonstrates that high-quality ZnO nanowires with an appropriate aspect ratio realize high-Q ultraviolet multipeak lasing based on F-P mode. These findings will benefit the design and fabrication of nanolasers based on nanowires.
Research on the influence of applying counterweight on the deflection and stability of cantilever beam of machine tool
Authors: Jiang Xinguo , Fang Xifeng , Li Zhiduo , Zhang Shengwen 
Published: September 2024

Abstract
The deflection and stability of the cantilever beam of the machine tool are important factors that affect the machining accuracy of the machine tool. Because of the space size, it needs to be weighted within a limited size. By designing different weighting schemes, the static analysis and modal analysis are carried out by finite element analysis software, and the influence law of the deflection and stress of the beam is obtained, so the appropriate weighting scheme is selected. Through the analysis of different schemes, it is known that the deflection of the beam is the smallest under the action of the arm of 900mm and the force of 1000N, and the machine tool structure is more compact, which is the key component of the subsequent machine tool.