bluuebunny/crossref_metadata_2025 huggingface dataset:
Generating magnon Bell states via parity measurement
Authors: Yan Jia-shun , Jing Jun
Published: April 2024

We propose a scheme to entangle two magnon modes based on parity measurements. In particular, we consider a system that two yttrium-iron-garnet spheres are coupled to a V-type superconducting qutrit through the indirect interactions mediated by cavity modes. An effective parity-measurement operator that can project the two macroscopic spin systems to the desired subspace emerges when the ancillary qutrit is projected onto the ground state. Consequently, conventional and multi-excitation magnon Bell states can be generated from any separable states with a nonvanishing population in the desired subspace. The target state can be distilled with a near-to-unit fidelity only by several rounds of measurements and can be stabilized in the presence of the measurement imperfection and environmental decoherence. In addition, a single-shot version of our scheme is obtained by shaping the detuning between magnon and qutrit in the time domain. Our scheme that does not rely on any nonlinear Hamiltonian brings insights into the entangled-state generation in massive ferrimagnetic materials via quantum measurements.
Flow and spray characteristics of a gas–liquid pintle injector under backpressure environment
Authors: Li Ziguang , Zhou Yaozhi , Cheng Peng , Bai Xiao , Li Qinglian
Published: April 2024

Both the flow and spray characteristics of a gas–liquid pintle injector element under the backpressure environment were investigated experimentally and numerically. The cold atomization tests were conducted with the backpressure range from 0.50 to 1.54 MPa. Both the interaction process between gas film and liquid jets and the detail distribution of the spray were obtained by the verified volume of fluid to discrete phase model. Results showed that there is a local high-pressure zone at the root of the liquid jets resulted by the collision of gas film and liquid jet. A semi-empirical model for predicting the discharge coefficient of the orifices is proposed considering the effect of local high-pressure zones based on the experiments. It was found that the discharge coefficient is mainly affected by the local momentum ratio (LMR) and ambient pressure. The discharge coefficient increases with the increase in LMR and ambient pressure. Before the primary breakup occurs, the liquid jets deform from rectangle jets to bow-shaped liquid films under the effect of the gas film. Then, both the gas and liquid mix in the range included by the gas passed by the windward surface and side of liquid jets. The droplet size is larger at the edges of the spray and the Sauter mean diameter (SMD) is beyond 100 μm. On the contrary, it is relatively small and uniform at the spray central, and the corresponding SMD is about 50 μm.
Numerical simulation of non-spherical microparticles' deposition on single fiber
Authors: Qian Ye-Cheng , Cai Rong-Rong , Zhang Li-Zhi
Published: April 2024

As a classical gas-solid two-phase flow system, the processes of fiber filtering microparticles are prevalent in nature and engineering. However, the impact of microparticle shape on fiber filtration processes is still largely unexplored. Herein, using the self-developed spheropolyhedral-based discrete element lattice Boltzmann method, the filtration process of non-spherical microparticles through a single fiber is investigated. Results show that the single fiber efficiency (SFE) for non-spherical particles exhibits a trend of initially increasing and subsequently decreasing trend with the increase in Stokes number (St), which is similar to the case of spherical particles. However, it is interesting to note that the peak values of SFE increase significantly with decreasing particle sphericity (ψ) and the corresponding St values become larger. As ψ decreases from 1.0 (sphere) to 0.671 (tetrahedron), the SFE increase from 0.205 to 0.49 and the corresponding St rises from 1.0 to 1.75. The enhanced SFE can be explained by elevated collision probability and adhesion probability, based on detailed particle kinematics and dynamics behavior analysis as well as microscopic depositional structure evaluation. The depositional structures of the non-spherical particles have larger capture areas, leading to higher initial collision probabilities. Meanwhile, the anisotropic collisions between non-spherical particles and fibers greatly contribute to higher secondary collision probabilities. In addition, compared to spherical particles of the same volume, the non-spherical particles experience greater fluid resistance, resulting in lower initial collision velocities and larger initial adhesion probabilities. The face-to-face contacts between non-spherical particles also lead to stronger interparticle adhesion and enhanced adhesion probabilities.
Effect of fabrication processes on BaTiO3 capacitor properties
Authors: Jiang Yizhe , Tian Zishen , Kavle Pravin , Pan Hao , Martin Lane W.
Published: April 2024

There is an increasing desire to utilize complex functional electronic materials such as ferroelectrics in next-generation microelectronics. As new materials are considered or introduced in this capacity, an understanding of how we can process these materials into those devices must be developed. Here, the effect of different fabrication processes on the ferroelectric and related properties of prototypical metal oxide (SrRuO3)/ferroelectric (BaTiO3)/metal oxide (SrRuO3) heterostructures is explored. Two different types of etching processes are studied, namely, wet etching of the top SrRuO3 using a NaIO4 solution and dry etching using an Ar+-ion beam (i.e., ion milling). Polarization-electric-field hysteresis loops for capacitors produced using both methods are compared. For the ion-milling process, it is found that the Ar+ beam can introduce defects into the SrRuO3/BaTiO3/SrRuO3 devices and that the milling depth strongly influences the defect level and can induce a voltage imprint on the function. Realizing that such processing approaches may be necessary, work is performed to ameliorate the imprint of the hysteresis loops via ex situ “healing” of the process-induced defects by annealing the ferroelectric material in a barium-and-oxygen-rich environment via a chemical-vapor-deposition-style process. This work provides a pathway for the nanoscale fabrication of these candidate materials for next-generation memory and logic applications.
Assigning macromolecular meaning to nonlinear continuum rheology
Authors: Poungthong P. , Giacomin A. J.
Published: April 2024

The Oldroyd 8-constant continuum framework has yielded elegant analytical solutions for many polymer processing flows. However, continuum frameworks are silent on macromolecular structure. We can assign macromolecular meaning to the continuum constants by bridging continuum frameworks to the macromolecular theory of polymeric liquid dynamics. When the Oldroyd 8-constant framework has been bridged to rigid dumbbell theory (two-step), no higher order rheology was predicted (ν1=ν2=0). By higher order, we mean the nonlinear rheology. This troubled Bird (1972), motivating his modified Oldroyd 8-constant continuum framework, which does predict higher order rheology, to which meaning in rigid dumbbell theory is assigned. By two-step, we mean we get the three Jeffreys model constants from the macromolecular expression for the complex viscosity, and then solve five equations simultaneously for the five remaining constants. In this paper, in three steps, we bridge the Bird 8-constant framework to the more versatile rotarance theory (general rigid bead-rod theory). By three-step, we mean we get the three Jeffreys model constants from the macromolecular expression for the complex viscosity, and then solve three equations simultaneously for the next three, and finally solving two equation simultaneously for the remaining two higher order constants. By versatile, we mean accommodating any axisymmetric macromolecular structure (including the rigid dumbbell). We find the constants in the Bird 8-constant framework to be explicit functions of just one dimensionless macromolecular attribute: the ratio of the moment of inertia about the molecular axis, to the moment about either transverse axis. We thus assign macromolecular meaning to the higher order rheology. In passing, we also discover a new bridge to the Oldroyd 8-constant framework (three-step), which also assigns macromolecular meaning to the higher order rheology.
Photonic crystal-coupled enhanced steering emission: A prism-free, objective-free, and metal-free loss-less approach for biosensing
Authors: Bhaskar Seemesh , Liu Weinan , Tibbs Joseph , Cunningham Brian T.
Published: April 2024

Diagnostic assays utilizing fluorescent reporters in the context of low abundance biomarkers for cancer and infectious disease can reach lower limits of detection through efficient collection of emitted photons into an optical sensor. In this work, we present the rational design, fabrication, and application of one-dimensional photonic crystal (PC) grating interfaces to accomplish a cost-effective prism-free, metal-free, and objective-free platform for augmentation of fluorescence emission collection efficiency. Guided mode resonance (GMR) of the PC is engineered to match the laser excitation (532 nm) and emission maximum (580 nm) of the radiating dipoles to arrive at optimized conditions. The photo-plasmonic hybrid nano-engineering using silver nanoparticles presented >110-fold steering fluorescence enhancement enabling placement of the sample between the excitation source and detector that are in a straight line. From the experimental and simulation inferences, we propose a radiating GMR model by scrutinizing the polarized emission properties of the hybrid substrate, in accordance with the radiating plasmon model. The augmented fluorescence intensity realized here with a simple detection instrument provides sub-nanomolar sensitivity to provide a path toward point-of-care scenarios.
AFM-IR study of interfacial nanostructures in high-temperature dilute nanocomposites
Authors: Zhu Wenyi , Rui Guanchun , Wetherington Maxwell Turner , Lee Jongcheol , Kim Seong H. , Zhang Q. M.
Published: April 2024

The dilute nanocomposite strategy facilitates a promising route for high-temperature polymer dielectrics to achieve high dielectric constant and energy density, robust breakdown strength, and low loss. The dielectric enhancement of the dilute nanocomposites strongly ties to the topological conditions of the nanofiller–polymer interface. Here, atomic force microscopy-based infrared spectroscopy was employed to observe the interfacial region of a high-temperature poly(arylene ether urea) (PEEU) dilute nanocomposite directly. The experimental results showed that the nanoparticles induce morphological changes in PEEU, and the interface region extends over 150 nm away from the nanofiller surfaces. Such nano-morphology changes are highly indicative of generating a large enhancement of the dielectric performance in the PEEU dilute nanocomposite.
High ODMR contrast and alignment of NV centers in microstructures grown on heteroepitaxial diamonds
Authors: Engels Jan , Weippert Jürgen , Luo Tingpeng , Kustermann Jan , Quellmalz Patricia , Mathes Niklas , Lindner Lukas , Giese Christian , Kirste Lutz , Knittel Peter , Jeske Jan , Lebedev Vadim
Published: April 2024

Heteroepitaxial chemical vapor deposition is the most promising option to fabricate wafer-scale monocrystalline diamonds for quantum applications. Previously, we demonstrated the feasibility to manufacture functional micrometer-sized pyramids on as-grown heteroepitaxial diamond as well as their quantum optical characteristics. Due to high background signals and microfabrication challenges, these pyramids could not compete with homoepitaxially grown structures. In this study, we overcame these problems with a nominally undoped buffer layer between the heteroepitaxial substrate and the pyramidal microstructure to reduce the signal-to-noise ratio from the substrate on the spin measurements of the nitrogen-vacancy (NV) center. Moreover, the microfabrication was improved to reach a higher angle of the pyramidal side plane, corresponding to the {111} facets. These improvements lead to pyramids on which each facet contains almost purely only one of the four possible NV orientations as shown by optically detected magnetic resonance (ODMR). ODMR shows a very high contrast of 19% without an external magnet and of 13% for a single spin resonance in the presence of a magnetic field. The contrast is more than doubled compared to our previous study. The T2* dephasing time of the NV centers of the samples ranges from 0.02 to 0.16 μs. The P1 center is a single substitutional nitrogen center, and the P1 densities range from 1.8 to 5 ppm.
Evaluating effects of physical soil and water conservation measures using farmers’ perception and soil analysis in southern Ethiopia
Authors: Ermias Habtamu , Wolka Kebede , Biazin Birhanu
Published: April 2024

Context Soil and water conservation (SWC) measures have been widely practiced on cultivated lands across regions but evidence on their effects is inadequate. Aims To examine the effects of variously aged SWC measures on cultivated land. Methods A total of 122 farm households were interviewed. At the 0–20 cm layer, soil samples (n = 59) were collected from soil bunds of <5 years, 5–10 years, and 10–15 years old, and no-bund adjacent fields and analysed in the laboratory. Key results Approximately 40% of respondents perceived soil erosion as a severe problem in their area. The respondents (70%) practiced the introduced SWC measures such as soil bunds. The introduced SWC measures are beneficial in improving soil fertility (78%) and thus 96% of the respondents were interested in repairing and sustaining it. The soil pH, soil organic carbon, total nitrogen, and available phosphorous were significantly (P < 0.05) greater in the fields with bunds of 10–15 years old than the fields with bunds of less than 10 years. The 10–15 year old bund showed greater soil organic carbon (37%), total nitrogen (40%), and available phosphorous (27%) than adjacent no-bund fields, implying that SWC can show effects on soil in the long term. Conclusions The results of the study revealed that the effects of physical SWC measures on soil properties can be observed after a decade of managing them. Implications Farmers are advised to repair and retain bunds if the erosion-prone areas are used for cultivating annual crop.
An inherited life-threatening arrhythmia model established by screening randomly mutagenized mice
Authors: Okabe Yuta , Murakoshi Nobuyuki , Kurebayashi Nagomi , Inoue Hana , Ito Yoko , Murayama Takashi , Miyoshi Chika , Funato Hiromasa , Ishii Koichiro , Xu Dongzhu , Tajiri Kazuko , Qin Rujie , Aonuma Kazuhiro , Murakata Yoshiko , Song Zonghu , Wakana Shigeharu , Yokoyama Utako , Sakurai Takashi , Aonuma Kazutaka , Ieda Masaki , Yanagisawa Masashi
Published: April 2024

Inherited arrhythmia syndromes (IASs) can cause life-threatening arrhythmias and are responsible for a significant proportion of sudden cardiac deaths (SCDs). Despite progress in the development of devices to prevent SCDs, the precise molecular mechanisms that induce detrimental arrhythmias remain to be fully investigated, and more effective therapies are desirable. In the present study, we screened a large-scale randomly mutagenized mouse library by electrocardiography to establish a disease model of IASs and consequently found one pedigree that exhibited spontaneous ventricular arrhythmias (VAs) followed by SCD within 1 y after birth. Genetic analysis successfully revealed a missense mutation (p.I4093V) of the ryanodine receptor 2 gene to be a cause of the arrhythmia. We found an age-related increase in arrhythmia frequency accompanied by cardiomegaly and decreased ventricular contractility in the
Ryr2
I4093V/+
mice. Ca
2+
signaling analysis and a ryanodine binding assay indicated that the mutant ryanodine receptor 2 had a gain-of-function phenotype and enhanced Ca
2+
sensitivity. Using this model, we detected the significant suppression of VA following flecainide or dantrolene treatment. Collectively, we established an inherited life-threatening arrhythmia mouse model from an electrocardiogram-based screen of randomly mutagenized mice. The present IAS model may prove feasible for use in investigating the mechanisms of SCD and assessing therapies.
Balancing economic and ecological functions in smallholder and industrial oil palm plantations
Authors: Wenzel Arne , Westphal Catrin , Ballauff Johannes , Berkelmann Dirk , Brambach Fabian , Buchori Damayanti , Camarretta Nicolò , Corre Marife D. , Daniel Rolf , Darras Kevin , Erasmi Stefan , Formaglio Greta , Hölscher Dirk , Iddris Najeeb Al-Amin , Irawan Bambang , Knohl Alexander , Kotowska Martyna M. , Krashevska Valentyna , Kreft Holger , Mulyani Yeni , Mußhoff Oliver , Paterno Gustavo B. , Polle Andrea , Potapov Anton , Röll Alexander , Scheu Stefan , Schlund Michael , Schneider Dominik , Sibhatu Kibrom T. , Stiegler Christian , Sundawati Leti , Tjoa Aiyen , Tscharntke Teja , Veldkamp Edzo , Waite Pierre-André , Wollni Meike , Zemp Delphine Clara , Grass Ingo
Published: April 2024

The expansion of the oil palm industry in Indonesia has improved livelihoods in rural communities, but comes at the cost of biodiversity and ecosystem degradation. Here, we investigated ways to balance ecological and economic outcomes of oil palm cultivation. We compared a wide range of production systems, including smallholder plantations, industrialized company estates, estates with improved agronomic management, and estates with native tree enrichment. Across all management types, we assessed multiple indicators of biodiversity, ecosystem functions, management, and landscape structure to identify factors that facilitate economic–ecological win–wins, using palm yields as measure of economic performance. Although, we found that yields in industrialized estates were, on average, twice as high as those in smallholder plantations, ecological indicators displayed substantial variability across systems, regardless of yield variations, highlighting potential for economic–ecological win–wins. Reducing management intensity (e.g., mechanical weeding instead of herbicide application) did not lower yields but improved ecological outcomes at moderate costs, making it a potential measure for balancing economic and ecological demands. Additionally, maintaining forest cover in the landscape generally enhanced local biodiversity and ecosystem functioning within plantations. Enriching plantations with native trees is also a promising strategy to increase ecological value without reducing productivity. Overall, we recommend closing yield gaps in smallholder cultivation through careful intensification, whereas conventional plantations could reduce management intensity without sacrificing yield. Our study highlights various pathways to reconcile the economics and ecology of palm oil production and identifies management practices for a more sustainable future of oil palm cultivation.
Substrate geometry affects population dynamics in a bacterial biofilm
Authors: Postek Witold , Staśkiewicz Klaudia , Lilja Elin , Wacław Bartłomiej
Published: April 2024

Biofilms inhabit a range of environments, such as dental plaques or soil micropores, often characterized by noneven surfaces. However, the impact of surface irregularities on the population dynamics of biofilms remains elusive, as most experiments are conducted on flat surfaces. Here, we show that the shape of the surface on which a biofilm grows influences genetic drift and selection within the biofilm. We culture

E
scherichia
coli

biofilms in microwells with a corrugated bottom surface and observe the emergence of clonal sectors whose size corresponds to that of the corrugations, despite no physical barrier separating different areas of the biofilm. The sectors are remarkably stable and do not invade each other; we attribute this stability to the characteristics of the velocity field within the biofilm, which hinders mixing and clonal expansion. A microscopically detailed computer model fully reproduces these findings and highlights the role of mechanical interactions such as adhesion and friction in microbial evolution. The model also predicts clonal expansion to be limited even for clones with a significant growth advantage—a finding which we confirm experimentally using a mixture of antibiotic-sensitive and antibiotic-resistant mutants in the presence of sublethal concentrations of the antibiotic rifampicin. The strong suppression of selection contrasts sharply with the behavior seen in range expansion experiments in bacterial colonies grown on agar. Our results show that biofilm population dynamics can be affected by patterning the surface and demonstrate how a better understanding of the physics of bacterial growth can be used to control microbial evolution.
Lipid scrambling is a general feature of protein insertases
Authors: Li Dazhi , Rocha-Roa Cristian , Schilling Matthew A. , Reinisch Karin M. , Vanni Stefano
Published: April 2024

Glycerophospholipids are synthesized primarily in the cytosolic leaflet of the endoplasmic reticulum (ER) membrane and must be equilibrated between bilayer leaflets to allow the ER and membranes derived from it to grow. Lipid equilibration is facilitated by integral membrane proteins called “scramblases.” These proteins feature a hydrophilic groove allowing the polar heads of lipids to traverse the hydrophobic membrane interior, similar to a credit card moving through a reader. Nevertheless, despite their fundamental role in membrane expansion and dynamics, the identity of most scramblases has remained elusive. Here, combining biochemical reconstitution and molecular dynamics simulations, we show that lipid scrambling is a general feature of protein insertases, integral membrane proteins which insert polypeptide chains into membranes of the ER and organelles disconnected from vesicle trafficking. Our data indicate that lipid scrambling occurs in the same hydrophilic channel through which protein insertion takes place and that scrambling is abolished in the presence of nascent polypeptide chains. We propose that protein insertases could have a so-far-overlooked role in membrane dynamics as scramblases.
OMA1 clears traffic jam in TOM tunnel in mammals
Authors: Sekine Shiori , Sekine Yusuke
Published: April 2024

Using an engineered mitochondrial clogger, Krakowczyk et al. (https://doi.org/10.1083/jcb.202306051) identified the OMA1 protease as a critical component that eliminates import failure at the TOM translocase in mammalian cells, providing a novel quality control mechanism that is distinct from those described in yeast.
Application of a mild data-driven technique to Lippmann–Schwinger inverse scattering in variable-exponent Lebesgue spaces for microwave imaging
Authors: Estatico Claudio , Schenone Valentina , Fedeli Alessandro , Randazzo Andrea
Published: April 2024

A mild data-driven approach for microwave imaging is considered in this paper. In particular, the developed technique relies upon the use of a Newton-type inversion scheme in variable-exponent Lebesgue spaces, which has been modified by including a data-driven operator to enforce the available a-priori information about the class of targets to be investigated. In this way, the performance of the method is improved, and the problems related to the possible convergence to local minima are mitigated. The effectiveness of the approach has been evaluated through numerical simulations involving the detection of defects inside (partially) known objects, showing good results.
Study of 113In(α, α) elastic scattering to determine α-optical potential relevant for astrophysical γ-process
Authors: Basak Dipali , Bar Tanmoy , Sahoo Lalit Kumar , Saha Sukhendu , Rana T K , Bhattacharya C , Manna S , Kundu Samir , Sahoo J K , Meena J K , Saha A K , Mondal Ashok Kumar , Basu Chinmay
Published: April 2024

The α-optical potential is one of the key input parameters used to measure the reaction rate of the (γ, α)-process using the Hauser-Feshbach statistical model and the principle of detailed balance. α-elastic scattering experiment on 113In p-nucleus was carried out in the energy range E
lab = 26−32 MeV. The vacuum evaporation technique was used to prepare the 113In target (∼86 μg cm−2). An energy-dependent local optical potential parameters set was obtained by analysing the experimental elastic scattering angular distribution data. The local potential parameters are extrapolated for lower energies and are used to calculate the 113In(α, γ) reaction cross-section.
Temperature field reconstruction based on femtosecond laser prepared of multiwavelength fibre bragg grating array
Authors: Niu Xiao , Si Jinhai , Chen Tao , Li Yingjie
Published: April 2024

Temperature field measurements are of great significance in industrial production, scientific research, and other fields. Contact temperature measurements usually achieve high spatial resolution by increasing the layout density of the sensors. However, in practical applications, achieving high-density sensor placement is often difficult. Therefore, when the number of sensors is limited, it is necessary to perform function fitting or interpolation of the temperature of the sampling points to reconstruct the temperature field distribution. This study proposed a temperature field reconstruction method based on femtosecond laser prepared multiwavelength fibre Bragg grating (FBG) array. A multiwavelength FBG array was prepared using the femtosecond laser phase mask method combined with stress stretching, and applied for measuring the temperature field distribution in a tubular high-temperature furnace. Cubic spline interpolation and backpropagation (BP) neural networks were used to construct two-dimensional temperature field models for the temperature field distribution data measured by the FBGs, and the prediction accuracies of the two models were compared. The test results show that the root mean square error of the temperature field distribution constructed using the BP neural network is 0.7333 °C, which is approximately 23.18% of the predicted results of the cubic spline interpolation model, indicating that it is a high-precision temperature field reconstruction method.
A simultaneous measurement method for multi-directional galloping of iced bundled conductors and its application in spatial galloping behavior
Authors: Cui Fujiang , Liu Peng , Wang Han , Li Zhiqiang , Xiang Jixin , Xu Jifeng , Ren He
Published: April 2024

The theoretical results indicate that iced bundled conductors experience spatial galloping due to wind-induced vibration, involving in-plane, out-of-plane, and torsional movements. To better understand the dynamic response of this behavior from an experimental perspective, an innovative experimental method has been proposed. The method can simultaneously measure the in-plane, out-of-plane, and torsional vibration signals of iced bundled conductors’ galloping. A testing system was established, and the method is applied in the galloping experiment of continuous iced bundled conductors, validating some theoretical results. This paper describes the construction of a wide-aperture, low-speed wind tunnel suitable for testing the galloping of continuous iced bundled conductors. A ‘cut-bury-glue’ method was proposed to create a model of continuous iced bundled conductors effectively, along with a method for connecting subconductors to improve experimental precision. The tests utilized laser displacement sensors and wireless posture sensors, considering the installation and data collection characteristics of the sensors. Through signal conversion, error correction, and other technical methods, simultaneous measurement of in-plane, out-of-plane, and torsional vibration signals was achieved. The spatial galloping behavior, changing with wind speed, exhibits limited-amplitude and synchronous characteristics. The participation of different modes shows elliptical orbital motion in single-mode galloping and ‘8’ shaped orbital motion in coupled-mode galloping. These results are consistent with previous theoretical research, offering a new approach to studying iced bundled conductors’ galloping.
Head surface strain measurement based wireless bolt sensor with self temperature compensating
Authors: Wang Tao , Zhang Wenxin , Yang Dan , Wang Hu , Lu Guangtao , Lu Mingge
Published: April 2024

Bolt loosening detection is crucial for ensuring the safe operation of equipment. Loosened bolts are hard to detect, and if left undetected, it can lead to catastrophic failures, especially for numerous bolts in large-scale structures. Therefore, the development of distributed bolt monitoring method and related sensors is highly necessary. In this paper, a novel bolt preload sensor with self-temperature compensation is proposed, based on the strain distribution of the bolt head end face. This study enhances previous research by conducting a detailed analysis of strain distribution at the edge of the bolt head surface. The finite element analysis results show that the bolt preload has almost no effect on the circumferential strain in the edge region of bolt head surface. Based on this feature, the strain gauge is applied circumferentially along the edge of the bolt head face as a temperature compensation gauge. In this way, the measuring strain gauge and the temperature compensation gauge can be integrated on the surface of the bolt head, thus achieving self-temperature compensation for the sensor. An experimental device has been established and the experimental results show that the designed sensor has excellent linearity to the bolt preload and effective temperature compensation. For the monitoring of numerous bolts with a wide distribution, a wireless sensing network utilizing the proposed sensor has been designed. The proposed wireless bolt sensor is easy to install and replace, without redesigning or changing the existing structure, thus providing a simple and effective way to monitor large number of bolts with wide distribution.
High precision vertical angle measurement system for calibration of various angle sensors and instruments
Authors: Kim Jong-Ahn , Lee Jae Yong , Kang Chu-Shik , Woo Jae Heun
Published: April 2024

A versatile measurement system was developed for efficient calibration of vertical angle sensors or instruments. The vertical angle measurement system (VAMS) comprises a precision rotation stage, a controller, and additional components for fixing an angle sensor or detecting angular deviation. It can generate single-axis rotation within ±120° range with a resolution of 0.01″. To detect angular deviation in angle instrument calibration, a special miniature autocollimator was developed using a diffractive optical element, providing high-precision angle measurement even with the short focal length of its lens. The performance of the VAMS was evaluated by comparing face angles of two optical polygons, measured by the VAMS and other reference systems. As typical exemplary calibrations, an electronic level and vertical angle readouts of a total station were calibrated with expanded uncertainty (k = 2) of 0.19″ and 0.51″, respectively.
2DLIW-SLAM:2D LiDAR-inertial-wheel odometry with real-time loop closure
Authors: Zhang Bin , Peng Zexin , Zeng Bi , Lu Junjie
Published: April 2024

Due to budgetary constraints, indoor navigation typically employs two-dimensional (2D) LiDAR rather than 3D LiDAR. However, the utilization of 2D LiDAR in simultaneous localization and mapping (SLAM) frequently encounters challenges related to motion degeneracy, particularly in geometrically similar environments. To address this problem, this paper proposes a robust, accurate, and multi-sensor-fused 2D LiDAR SLAM system specifically designed for indoor mobile robots. To commence, the original LiDAR data undergoes meticulous processing through point and line extraction. Leveraging the distinctive characteristics of indoor environments, line–line constraints are established to complement other sensor data effectively, thereby augmenting the overall robustness and precision of the system. Concurrently, a tightly-coupled front-end is created, integrating data from the 2D LiDAR, inertial measurement unit, and wheel odometry, thus enabling real-time state estimation. Building upon this solid foundation, a novel global feature point matching-based loop closure detection algorithm is proposed. This algorithm proves highly effective in mitigating front-end accumulated errors and ultimately constructs a globally consistent map. The experimental results indicate that our system fully meets real-time requirements. When compared to cartographer, our system not only exhibits lower trajectory errors but also demonstrates stronger robustness, particularly in degeneracy problem. We open source our methods here: https://github.com/LittleDang/2DLIW-SLAM.
Performance degradation trend prediction of proton exchange membrane fuel cell based on GA-TCN
Authors: Zhao Ziliang , Shen Senhao , Wang Zhangu
Published: April 2024

To improve the prediction accuracy of the performance degradation trend of proton exchange membrane fuel cell (PEMFC), this paper proposes a temporal convolutional network (TCN) model based on genetic algorithm (GA) optimization to predict the performance degradation trend of PEMFC. Firstly, variational mode decomposition and wavelet threshold denoising algorithms are used to denoise the original data. Then the hyperparameters of the TCN model are optimized by GA, and the GA-TCN model for predicting the performance degradation trend of PEMFC is constructed. Finally, this paper uses the PEMFC stack degradation experimental dataset disclosed in the IEEE PHM 2014 Data Challenge to verify, and compares the proposed model with the backpropagation neural networks model, the long short-term memory model and the classical TCN model. The results show that the proposed method has the highest performance degradation trend prediction accuracy. In particular, when the training dataset accounts for 30%, i.e. the training samples are small, the root mean square error, mean absolute error and mean absolute percentage error of the GA-TCN model are 0.004 726, 0.003 119 and 9.62%, respectively, which are 14.48%, 20.05% and 2.42% lower than that of the classical TCN model. Consequently, this methodology can forecast the degradation trend of PEMFC with high accuracy.
A high-accuracy system model and accuracy evaluation method for transfer alignment
Authors: Yang Jie , Wang Xinlong , Wang Bin , Hu Xiaodong
Published: April 2024

With the increasing demand for high-accuracy navigation, distributed payloads put forward higher requirements for the initial alignment accuracy of their equipped slave inertial navigation systems (INSs). However, the existing transfer alignment models have poor compensation effect on flexible deformation, resulting in low alignment accuracy. Moreover, these models cannot accurately evaluate the accuracy of transfer alignment due to ignoring the errors of the master INS. To address these two problems, a new high-accuracy transfer alignment system model is established by comprehensively considering errors of the master and slave INSs. Further, the propagation characteristics of the master and slave inertial sensor errors in transfer alignment are analyzed, and the relationship expression between the master and slave inertial sensor accuracy and the transfer alignment accuracy is derived. Thus, the accuracy of transfer alignment can be pre-evaluated according to the master and slave inertial sensor accuracy. The experiment results show that the alignment accuracy of the proposed method is improved by more than 71.56% compared with the traditional methods, and the relative errors between the proposed accuracy evaluation method and the Monte Carlo simulations are less than 9.14%. Thus, the correctness, effectiveness and superiority of the proposed method are verified.
Remaining life prediction of rolling bearings with secondary feature selection and BSBiLSTM
Authors: Song Feng , Wang Zhihai , Liu Xiaoqin , Ren Guoai , Liu Tao
Published: April 2024

Rolling element bearings are critical components in rotating machinery. To tackle the problem of difficult to accurately characterize the operating state of rolling bearings caused by irrelevance and varying sensitivity of multiple features to performance degradation, and introduction of subjective errors in determination of hyperparameters of deep learning models, which can affect the accuracy and efficiency of remaining useful life (RUL) prediction. To address these challenges, this paper proposed a novel RUL prediction method for rolling bearings with secondary feature selection and Bayesian optimization of self-attention mechanisms for bidirectional long short-term memory (BSBiLSTM). Firstly, multi-domain features are extracted from noise-reduced vibration signals. Then, a three-criterion constraint-based feature selection algorithm is used and a secondary selection algorithm with Pearson correlation coefficient is proposed to improve data quality. Next, the 3σ criterion is integrated to determine the first prediction time for rolling bearings and to divide the degradation stage. Subsequently, the BiLSTM model with Bayesian optimization and self-attention mechanism is proposed to predict the RUL of rolling bearings to further improve the algorithm efficiency. Finally, experimental validation is carried out based on the PRONOSTIA platform dataset and the XJTU-SY rolling bearing dataset, and the results show that the method proposed in this paper is better than many mainstream life prediction methods for rolling bearings at present, and the prediction accuracy is higher.
Enhanced photoelectrochemical water splitting by a 3D hierarchical sea urchin-like structure: ZnO nanorod arrays on TiO2 hollow hemisphere
Authors: Lee Wei Cheat , Fang Yuanxing , Le Huyen , Hodgson Ronan , Chan Hon Wing Boaz , Qian Rong , Alsohaimi Ibrahim H , Canciani Giacomo E , Alhar Munirah Sulaiman , Chen Qiao
Published: April 2024

A hierarchical sea urchin-like hybrid metal oxide nanostructure of ZnO nanorods deposited on TiO2 porous hollow hemispheres with a thin zinc titanate interface layer is specifically designed and synthesized to form a combined type I straddling and type II staggered junctions. The HHSs, synthesized by electrospinning, facilitate light trapping and scattering. The ZnO nanorods offer a large surface area for improved surface oxidation kinetics. The interface layer of zinc titanate (ZnTiO3) between the TiO2 HHSs and ZnO nanorods regulates the charge separation in a closely coupled hierarchy structure of ZnO/ZnTiO3/TiO2. The synergistic effects of the improved light trapping, charge separation, and fast surface reaction kinetics result in a superior photoconversion efficiency of 1.07% for the photoelectrochemical water splitting with an outstanding photocurrent density of 2.8 mA cm−2 at 1.23 V versus RHE.
Influence of printing parameters and hinge structure on shape memory performance at the hinge in 4D origami structures
Authors: Liu Kecheng , Yang Fei , Wang Xingyu , Yu Han , Zhang Juan , Wang Xingsheng , Mei Xinliang
Published: April 2024

Four-dimensionally (4D) printing technology effectively demonstrates the advantages of portability, foldability, and improved mechanical properties in origami structures. This study highlights the significance of printing process parameters and origami hinge structures in ensuring rapid and complete deployment of origami structures. Polylactic acid based semicrystalline shape memory polymer was utilized to produce 4D printed origami structures. Through response surface analysis methods and bending tests, optimal printing parameters were determined, including layer thickness of 0.31 mm, extrusion speed of 17 mm s−1, and infill percentage of 71%. Additionally, the study designed a U-shaped hinge and analyzed its recovery mechanism through micromorphology of bending hinges and recovery experiments.
A novel memristor Hopfield neural network with homogeneous coexisting multi-scroll attractors
Authors: Huang Lilian , Chen Fangyi , Yang Yan , Zheng Lei
Published: April 2024

Compared to conventional single-scroll or double-scroll attractors, multi-scroll chaotic attractors possess wide potential for application due to their adjustability and complex topology. However, neural network models for generating multiple scrolls are often implemented using memristors with piecewise nonlinear functions. To further explore multi-scroll attractors with different working mechanisms,a unique memristor containing a group of hyperbolic tangent functions is designed and then applied in a three-dimensional Hopfield neural network (HNN). The proposed memristive Hopfield neural network (MHNN) has multi-scroll chaotic attractors, where the number and parity of the scrolls be changed by adjusting the control parameters of the memristor. The complex dynamical behaviors of MHNN are studied by utilizing diverse numerical modeling approaches like bifurcation diagrams, Lyapunov exponents and phase plot. In addition, the proposed MHNN also has a complicated offset boosting coexisting behavior. By selecting suitable parameters, multiple coexisting chaotic attractors could be obtained. Homogeneous coexisting multi-scroll attractors can be shifted in multiple directions including unidirectional, planar and spatial ones. Moreover, theoretically speaking, there could be an infinite number of coexisting attractors. Finally, experimental results are validated through numerical simulations and circuit experiments to confirm the feasibility of the proposed MHNN model.
Laser processing characteristics of PCD tool and modeling analysis
Authors: Tan Ruiwang , Wang Xu , Yu Zhanjiang , Shi Guangfeng , Yang Shen , Li Yiquan , Xu Jinkai
Published: April 2024

Through in-depth analysis of the experimental details and forming patterns of the nanosecond laser ablation polycrystalline diamond (PCD) textured tool processing system, this study explores the microscopic morphology and dimensions of micro-pits texture on the surface of PCD tools influenced by defocus amount, laser power, and pulse frequency. Experimental results indicate that the micro-pit textures generated under different parameters exhibit diversity, including rounded structure, fragments, recast layers, and heat-affected zones. The diameter and depth of micro-pits are comprehensively affected by defocus amount, laser power, and pulse frequency, showing complex patterns. After a thorough analysis of the effects of each parameter on the texture morphology, an artificial neural network (ANN) model is introduced for the prediction of micro-pit dimensions. Through model training and optimization, accurate predictions of micro-pit diameter and depth are obtained. In comparison to traditional regression models, the ANN model demonstrates outstanding predictive performance, validating its applicability in complex machining processes. This study not only provides a profound understanding of the processing patterns of PCD textured tools but also offers an effective predictive model for the optimization and control of similar future machining processes.
Physical properties and maximum allowable mass-radius relation of complexity-free compact stellar objects within modified
gravity formalism*
Authors: Jasim M. K. , Maurya S. K. , Errehymy Abdelghani , Khalid Jassim Ali , Sooppy Nisar Kottakkaran , Abdel-Aty Abdel-Haleem
Published: April 2024

This paper investigates the physical properties and predicted radii of compact stars generated by the Tolman-IV complexity-free model within the background of modified gravity theory, particularly the

-gravity theory, under complexity formalism for a spherically symmetric spacetime proposed by L. Herrera [Phys Rev D 97: 044010, 2018]. By solving the resulting set of differential equations, we obtain the explicit forms of the energy-momentum (EM) tensor components, including the density, radial pressure, and tangential pressure. The influence of the parameter χ on various physical properties of the star is thoroughly investigated. The model undergoes a series of rigorous tests to determine its physical relevance. The findings indicate that the model exhibits regularity, stability, and a surface with vanishing pressure. The boundary of this surface is determined by carefully selecting the parameter space. The complexity method employed in

gravity offers an interesting approach for developing astrophysical models that are consistent with observable events as demonstrated by recent experiments. In this regard, we use observational data from the GW190814 event, detected by the LIGO and Virgo observatories, to investigate the validity of the Tolman-IV model in

gravity. The analysis includes comparing the model's predictions with the observed characteristics of the compact object involved in the merger. In addition, data from two-millisecond pulsars, PSR J1614-2230 and PSR J0952-0607, are incorporated to further constrain the theoretical theories. However, we present a diagram depicting the relationship between the total mass and radius of the compact object candidates for different values of χ.
Timing and Spectral Analysis of the Black Hole X-Ray Binary MAXI J1803-298 with Insight-HXMT Data
Authors: Xu Ying-Chen , Qu Jin-Lu , Méndez M. , Ma Rui-Can , Ji Long , Zhang Liang , Huang Yue , Bu Qing-Cui , Song Li-Ming
Published: April 2024

We present a comprehensive analysis of the 2021 outburst of MAXI J1803–298 utilizing observations of the Insight-Hard X-ray Modulation Telescope (Insight-HXMT) spanning from the low hard state to the high soft state. Within the Insight-HXMT data set, compared to the previous work, we identify a more prolonged presence of type-C quasi-periodic oscillations (QPOs) with centroid frequencies ranging from ∼0.16 to 6.3 Hz, which present correlations with the hardness ratio and the photon index of the Comptonized component. For QPO frequencies less than ∼2 Hz, the QPO phase lags are hard (photons of 10–19 keV arrive later than those of 1–4 keV), while at higher frequencies, the lags become soft at and above ∼4 Hz. Furthermore, the spectra in all Insight-HXMT observations consist of a multi-color blackbody component and a Comptonized component, as commonly observed in classical black hole X-ray binaries. We analyze state transitions and the evolution of accretion geometry in this work. The fitted inner disk radius increases abnormally during the low hard state, hypothesized to result from the corona condensing onto the inner disk. Additionally, two significant drops in flux are observed during the soft intermediate state, maybe implying changes in the corona/jet and the disk, respectively.