bluuebunny/crossref_metadata_2025 huggingface dataset:
Bifurcation analysis of a two-neuron central pattern generator model for both oscillatory and convergent neuronal activities
Authors: Muramatsu Kotaro , Kori Hiroshi
Published: September 2024

The neural oscillator model proposed by Matsuoka is a piecewise affine system that exhibits distinctive periodic solutions. Although such typical oscillation patterns have been widely studied, little is understood about the dynamics of convergence to certain fixed points and bifurcations between the periodic orbits and fixed points in this model. We performed fixed point analysis on a two-neuron version of the Matsuoka oscillator model, the result of which explains the mechanism of oscillation and the discontinuity-induced bifurcations such as subcritical/supercritical Hopf-like, homoclinic-like and grazing bifurcations. Furthermore, it provided theoretical predictions concerning a logarithmic oscillation-period scaling law and noise-induced oscillations observed around those bifurcations. These results are expected to underpin further investigations into oscillatory and transient neuronal activities concerning central pattern generators.
Numerical study on the motion characteristics of free fall lifeboats entering calm water and rough sea
Authors: Lu Wenhao , Wu Xiaodi , Zha Ruosi
Published: September 2024

As ocean engineering operations extend into deeper seas, the working environment becomes increasingly complex, making free fall lifeboats (FFLBs) more vital for maritime disaster rescues. Unlike traditional davit-launched lifeboats, FFLBs are propelled into the water at a specific velocity and angle, engaging in a complex motion process of launch, impact, submersion, and resurfacing. Therefore, to assess the safety of FFLBs, this paper regarding the lifeboat as a rigid body aims to investigate the six-degree-of-freedom motion characteristics of lifeboat entering the water with different entry angles θ and wave environment, with a specific focus on analyzing the primary causes of capsizing. The numerical simulations of water entry with various θ, wave heights H, and relative entry positions are carried out by combining large eddy simulation and overset mesh technology. The free surface is captured by the volume of fluid method, and the attitude change, acceleration change, motion trajectory, and free surface evolution law of lifeboats are analyzed. The findings suggest that lifeboats can enter calm water safely at θ of 20°–50° and maintain a stable posture. Moreover, in extreme conditions where θ is either 0° or 90°, there is a high risk of entry failure due to excessive vertical acceleration and poor motion attitude, respectively. Furthermore, when facing waves, lifeboats experience reduced horizontal displacement when entering at peak and downward zero point compared to calm water conditions, which poses challenges for avoiding potential dangers.
Sufficient condition for reliable logic operations in an over damped bistable system driven by Gaussian white noise
Authors: Zhu Weiyi , Yang Bo
Published: September 2024

In this paper, we investigate an overdamped bistable system subject to Gaussian white noise and logical inputs. By solving and estimating the steady distribution of the corresponding Fokker–Planck equation and considering the two essential features of the reliable logic operations (RLOs)—initial value independence and sign invariance—we establish the sufficient condition for RLO occurrence and identify parametric resonance phenomena in the system. Our numerical simulations confirm the reliability and accuracy of the theoretical results. This work offers insights into enhancing the accuracy of stochastic systems, particularly in the realm of logical stochastic resonance, thereby contributing to advancements in understanding and controlling stochastic dynamical systems.
Steady state stability features of the electron–positron plasma diode in a mode with particle reflection from potential extrema
Authors: Bakaleinikov L. A. , Kuznetsov V. I. , Flegontova E. Yu. , Barsukov D. P. , Morozov I. K.
Published: September 2024

Steady state stability features of a diode with electrons and positrons entering from opposite boundaries and moving without collisions in plasma are numerically studied. The most complex regime when charged particles are reflected from potential barriers is considered. This problem arises, in particular, when modeling pulsar diodes. A small perturbation evolution is studied. It has been established that at the initial stage of the process the perturbation amplitude changes in time according to an exponential law. It is shown that stationary solutions with a potential barrier for electrons located near the electron-emitting electrode and a potential barrier for positrons located near the opposite electrode are stable when the inter-electrode distance is below a certain threshold. As the inter-electrode distance increases, the solutions become unstable. Solutions of another type when barriers reflecting particles are located in the opposite to the emitting electrode parts of the gap are also studied. However, these solutions turned out to be unstable.
Thermal management optimization of natural convection in a triangular chamber: Role of heating positions and ternary hybrid nanofluid
Authors: Ighris Youness , Qaffou Mohsine , Baliti Jamal , Elguennouni Youssef , Hssikou Mohamed
Published: September 2024

In this paper, we used the multi-relaxation time lattice Boltzmann method to investigate natural convection in a triangular-shaped cavity filled with a tri-hybrid nanofluid. The cavity is partially heated by a chip of fixed size (l=L/2), the position of which varies on the left and bottom walls in order to find the optimal positions. The inclined side is maintained at a cool temperature, while the other parts are adiabatic. A detailed analysis is carried out on the impact of four essential parameters on the optimization of heat transfer: the Rayleigh number, ranging between Ra = 103 and Ra = 106; the partial heating position, showing the cavity in six different configurations; the fluid type, including pure water, nanofluid, hybrid nanofluid, and tri-hybrid nanofluid; and finally, the volume concentration of the nanoparticles for three values, ϕ = 0%, 3%, and 6%. Results are presented in the form of isotherms, streamlines, temperature and velocity profiles, and the mean Nusselt number values. As the results show, the position of the partial heater plays a crucial role, influencing natural convection heat transfer significantly in certain positions at all values of the Rayleigh number. The type of fluid has a remarkable impact on the amplification of natural convection at large values of the Rayleigh number, where the buoyancy force becomes strong. Notably, the use of tri-hybrid nanofluid shows a clear improvement in natural convection heat transfer. Furthermore, a substantial increase in thermal transmittance is observed with an increasing nanoparticle volume fraction. The validation results agree well with both numerical results and experimental data published in the literature.
Hall MHD waves: A fundamental departure from their MHD counterparts
Authors: Mahajan Swadesh M. , Sharma Prerana , Lingam Manasvi
Published: September 2024

It is demonstrated through a succinct derivation as to how the linear waves in Hall magnetohydrodynamics (HMHD) constitute a fundamental departure from the standard MHD waves. Apart from modifying the conventional MHD spectrum, the Hall current induces a distinct and new branch consisting of purely circularly polarized waves that may become the representative shear waves.
Dynamics of femtosecond laser-driven liquid jets
Authors: Chen Yutong , Hu Yuqi , Wang Ying , Jiang Yuanfei , Chen Anmin , Jin Mingxing
Published: September 2024

The complex dynamics of flowing liquids under external stimuli can lead to significant changes in the direction of liquid jets. In this study, we utilized a femtosecond laser to drive a flowing liquid column and analyzed the effect of varying laser energies on the direction of the liquid flow. Additionally, we examined how the diameter and volume of the liquid column influenced its directional behavior when driven by the laser. By comparing the driving angles under different conditions, we explored the principles governing the femtosecond laser-driven liquid columns. These findings offer valuable insights into the field of liquid dynamics, showcasing femtosecond lasers as a good method for controlling liquid flows.
ACCESS-S2 seasonal forecasts of rainfall and the SAM–rainfall relationship during the grain growing season in south-west Western Australia
Authors: Firth Rebecca , Kala Jatin , Hudson Debra , Hawke Kerryn , Marshall Andrew
Published: September 2024

South-west Western Australia (SWWA) is home to a world class grains industry that is significantly affected by periods of drought. Previous research has shown a link between the Southern Annular Mode (SAM) and rainfall in SWWA, especially during winter months. Hence, the predictability of the SAM and its relationship to SWWA rainfall can potentially improve forecasts of SWWA drought, which would provide valuable information for farmers. In this paper, focusing on the 0-month lead time forecast, we assess the bias and skill of ACCESS-S2, the Australian Bureau of Meteorology’s current operational sub-seasonal to seasonal forecasting system, in simulating seasonal rainfall for SWWA during the growing season (May–October). We then analyse the relationship between the SAM and SWWA precipitation and how well this is captured in ACCESS-S2 as well as how well ACCESS-S2 forecasts the monthly SAM index. Finally, ACCESS-S2 rainfall forecasts and the simulation of SAM are assessed for a case study of extreme drought in 2010. Our results show that forecasts tend to have greater skill in the earlier part of the season (May–July). ACCESS-S2 captures the significant inverse SAM–rainfall relationship but underestimates its strength. The model also shows overall skill in forecasting the monthly SAM index and simulating the MSLP and 850-hPa wind anomaly patterns associated with positive and negative SAM phases. However, for the 2010 drought case study, ACCESS-S2 does not indicate strong likelihoods of the upcoming dry conditions, particularly for later in the growing season, despite predicting a positive (although weaker than observed) SAM index. Although ACCESS-S2 is shown to skillfully depict the SAM–SWWA rainfall relationship and generally forecast the SAM index well, the seasonal rainfall forecasts still show limited skill. Hence it is likely that model errors unrelated to the SAM are contributing to limited skill in seasonal rainfall forecasts for SWWA, as well as the generally low seasonal-timescale predictability for the region.
Joint trajectory inference for single-cell genomics using deep learning with a mixture prior
Authors: Du Jin-Hong , Chen Tianyu , Gao Ming , Wang Jingshu
Published: September 2024

Trajectory inference methods are essential for analyzing the developmental paths of cells in single-cell sequencing datasets. It provides insights into cellular differentiation, transitions, and lineage hierarchies, helping unravel the dynamic processes underlying development and disease progression. However, many existing tools lack a coherent statistical model and reliable uncertainty quantification, limiting their utility and robustness. In this paper, we introduce VITAE (Variational Inference for Trajectory by AutoEncoder), a statistical approach that integrates a latent hierarchical mixture model with variational autoencoders to infer trajectories. The statistical hierarchical model enhances the interpretability of our framework, while the posterior approximations generated by our variational autoencoder ensure computational efficiency and provide uncertainty quantification of cell projections along trajectories. Specifically, VITAE enables simultaneous trajectory inference and data integration, improving the accuracy of learning a joint trajectory structure in the presence of biological and technical heterogeneity across datasets. We show that VITAE outperforms other state-of-the-art trajectory inference methods on both real and synthetic data under various trajectory topologies. Furthermore, we apply VITAE to jointly analyze three distinct single-cell RNA sequencing datasets of the mouse neocortex, unveiling comprehensive developmental lineages of projection neurons. VITAE effectively reduces batch effects within and across datasets and uncovers finer structures that might be overlooked in individual datasets. Additionally, we showcase VITAE’s efficacy in integrative analyses of multiomic datasets with continuous cell population structures.
Depressive symptoms during the transition to adolescence: Left hippocampal volume as a marker of social context sensitivity
Authors: Martinez Matias , Cai Tianying , Yang Beiming , Zhou Zexi , Shankman Stewart A. , Mittal Vijay A. , Haase Claudia M. , Qu Yang
Published: September 2024

The transition to adolescence is a critical period for mental health development. Socio-experiential environments play an important role in the emergence of depressive symptoms with some adolescents showing more sensitivity to social contexts than others. Drawing on recent developmental neuroscience advances, we examined whether hippocampal volume amplifies social context effects in the transition to adolescence. We analyzed 2-y longitudinal data from the Adolescent Brain Cognitive Development (ABCD
®
) study in a diverse sample of 11,832 youth (mean age: 9.914 y; range: 8.917 to 11.083 y; 47.8% girls) from 21 sites across the United States. Socio-experiential environments (i.e., family conflict, primary caregiver’s depressive symptoms, parental warmth, peer victimization, and prosocial school environment), hippocampal volume, and a wide range of demographic characteristics were measured at baseline. Youth’s symptoms of major depressive disorder were assessed at both baseline and 2 y later. Multilevel mixed-effects linear regression analyses showed that negative social environments (i.e., family conflict, primary caregiver’s depressive symptoms, and peer victimization) and the absence of positive social environments (i.e., parental warmth and prosocial school environment) predicted greater increases in youth’s depressive symptoms over 2 y. Importantly, left hippocampal volume amplified social context effects such that youth with larger left hippocampal volume experienced greater increases in depressive symptoms in more negative and less positive social environments. Consistent with brain–environment interaction models of mental health, these findings underscore the importance of families, peers, and schools in the development of depression during the transition to adolescence and show how neural structure amplifies social context sensitivity.
ER-associated degradation ligase HRD1 links ER stress to DNA damage repair by modulating the activity of DNA-PKcs
Authors: Xiang Zhiyuan , Hou Guixue , Zheng Shanliang , Lu Minqiao , Li Tianyu , Lin Qingyu , Liu Hao , Wang Xingwen , Guan Tianqi , Wei Yuhan , Zhang Wenxin , Zhang Yi , Liu Chaoran , Li Li , Lei Qun-ying , Hu Ying
Published: September 2024

Proteostasis and genomic integrity are respectively regulated by the endoplasmic reticulum–associated protein degradation (ERAD) and DNA damage repair signaling pathways, with both pathways essential for carcinogenesis and drug resistance. How these signaling pathways coordinate with each other remains unexplored. We found that ER stress specifically induces the DNA-PKcs-regulated nonhomologous end joining (NHEJ) pathway to amend DNA damage and impede cell death. Intriguingly, sustained ER stress rapidly decreased the activity of DNA-PKcs and DNA damage accumulated, facilitating a switch from adaptation to cell death. This DNA-PKcs inactivation was caused by increased KU70/KU80 protein degradation. Unexpectedly, the ERAD ligase HRD1 was found to efficiently destabilize the classic nuclear protein HDAC1 in the cytoplasm, by catalyzing HDAC1’s polyubiquitination at lysine 74, at a late stage of ER stress. By abolishing HDAC1-mediated KU70/KU80 deacetylation, HRD1 transmits ER signals to the nucleus. The resulting enhanced KU70/KU80 acetylation provides binding sites for the nuclear E3 ligase TRIM25, resulting in the promotion of polyubiquitination and the degradation of KU70/KU80 proteins. Both in vitro and in vivo cancer models showed that genetic or pharmacological inhibition of HADC1 or DNA-PKcs sensitizes colon cancer cells to ER stress inducers, including the Food and Drug Administration–approved drug celecoxib. The antitumor effects of the combined approach were also observed in patient-derived xenograft models. These findings identify a mechanistic link between ER stress (ERAD) in the cytoplasm and DNA damage (NHEJ) pathways in the nucleus, indicating that combined anticancer strategies may be developed that induce severe ER stress while simultaneously inhibiting KU70/KU80/DNA-PKcs-mediated NHEJ signaling.
Different temporal dynamics of foveal and peripheral visual processing during fixation
Authors: de la Malla Cristina , Poletti Martina
Published: September 2024

Humans explore visual scenes by alternating short fixations with saccades directing the fovea to points of interest. During fixation, the visual system not only examines the foveal stimulus at high resolution, but it also processes the extrafoveal input to plan the next saccade. Although foveal analysis and peripheral selection occur in parallel, little is known about the temporal dynamics of foveal and peripheral processing upon saccade landing, during fixation. Here we investigate whether the ability to localize changes across the visual field differs depending on when the change occurs during fixation, and on whether the change localization involves foveal, extrafoveal processing, or both. Our findings reveal that the ability to localize changes in peripheral areas of the visual field improves as a function of time after fixation onset, whereas localization accuracy for foveal stimuli remains approximately constant. Importantly, this pattern holds regardless of whether individuals monitor only foveal or peripheral stimuli, or both simultaneously. Altogether, these results show that the visual system is more attuned to the foveal input early on during fixation, whereas change localization for peripheral stimuli progressively improves throughout fixation, possibly as a consequence of an increased readiness to plan the next saccade.
Tip extension and simultaneous multiple fission in a filamentous bacterium
Authors: Chimileski Scott , Borisy Gary G. , Dewhirst Floyd E. , Mark Welch Jessica L.
Published: September 2024

Organisms display an immense variety of shapes, sizes, and reproductive strategies. At microscopic scales, bacterial cell morphology and growth dynamics are adaptive traits that influence the spatial organization of microbial communities. In one such community—the human dental plaque biofilm—a network of filamentous
Corynebacterium matruchotii
cells forms the core of bacterial consortia known as hedgehogs, but the processes that generate these structures are unclear. Here, using live-cell time-lapse microscopy and fluorescent D-amino acids to track peptidoglycan biosynthesis, we report an extraordinary example of simultaneous multiple division within the domain
Bacteria
. We show that
C. matruchotii
cells elongate at one pole through tip extension, similar to the growth strategy of soil-dwelling
Streptomyces
bacteria. Filaments elongate rapidly, at rates more than five times greater than other closely related bacterial species. Following elongation, many septa form simultaneously, and each cell divides into 3 to 14 daughter cells, depending on the length of the mother filament. The daughter cells then nucleate outgrowth of new thinner vegetative filaments, generating the classic “whip handle” morphology of this taxon. Our results expand the known diversity of bacterial cell cycles and help explain how this filamentous bacterium can compete for space, access nutrients, and form important interspecies interactions within dental plaque.
The rhotics of the Salvador, Bahia variety of Brazilian Portuguese
Authors: Jagiella Trey , Clements J. Clancy
Published: September 2024

Brazilian Portuguese has two rhotic phonemes: the alveolar flap /ɾ/ and another variable phoneme. This phoneme has
been cited as velar, uvular, and glottal fricatives, as well as alveolar trills and approximants. Variability of surface forms
occurs both within and across varieties. This phoneme occurs in simple onsets, codas, and intervocalically. Deletion of the
phoneme is common, particularly in word-final position. The goal of this project is to explore the variation in rhotic production
in Salvador, particularly with regards to substrate influence. Ten participants read predetermined stimuli of isolated tokens and
sentences, with a total of 1409 instances of the phoneme. The findings indicate that the range of possible surface forms is more
variable than previously cited, including palatal and uvular fricatives among others. We suggest that the degree of variability of
rhotic production in Salvador may be due to past contact between Africans and Portuguese in the city.
Modeling Linguistic Landscapes
Authors: Buschfeld Sarah , Weihs Claus , Ronan Patricia
Published: September 2024

Much work in Linguistic Landscapes approaches multilingual landscapes in qualitative terms; inferential
statistical approaches are still underrepresented. The present paper adds to filling this methodological gap by investigating the
Linguistic Landscapes of St Martin, a highly multilingual, eastern Caribbean island, divided into a formerly Dutch-colonized and
French-colonized part. It does so by employing an inferential statistical method to study the nature of linguistic diversity on
signs. Based on 372 and 373 signs respectively for each of the commercial districts of Philipsburg and Marigot, we quantitatively
analyze the occurrences of languages on the different signs and statistically model the data by means of Multi-Label
Classification (MLC; e.g. Rivolli & de Carvalho, 2018). The results show that both
shopping districts are characterized by multilingual patterns of Linguistic Landscapes but with differences in their exact
linguistic setups, most importantly the interplay and relationships between different languages, motivated by differences in their
sociolinguistic setup.
Towards a distinction between non-euphemistic and euphemism-based politically correct expressions
Authors: Golubeva Tatiana
Published: September 2024

This qualitative research is the first attempt to analyse differences in the interpretation of politically correct (PC) expressions by using relevance-theoretic and lexical pragmatics tools. The results suggest that PC language can be non-euphemistic and euphemism-based. Non-euphemistic PC expressions achieve relevance by explicitly communicating their lexically encoded conceptual content. Euphemism-based PC expressions become relevant by communicating some concepts and propositions that are not lexically encoded by them and are inferred logically from the utterance context or/and by accessing encyclopaedic information. These concepts and propositions constitute euphemistic meaning and are recovered at explicit and implicit levels, as well as with varying degrees of strength.
The relationship between nutrition and intestinal health in newborn lambs
Authors: Uysal Soner , Uysal Ayse
Published: September 2024

As with all animals, the period in their lives when lambs are most vulnerable is the period before and immediately after birth. Because this period (the suckling period) is the period of clinging to life in an environment open to microorganism contamination after the sterile uterine environment. It is very important that this difficulty can be reduced with good care and feeding practices that must be applied during this period and that the puppy lamb can have a healthy and highly productive life during this risky period and in the future. Regulation and enhancement of the intestinal microbiome is a crucial aspect for optimizing the health and performance of farm animals. This is mainly because diet and management practices greatly affect the intestinal microbiota, resulting in changes in nutrient utilization and the immune system. The intestinal health of newborn lambs is affected by feeding manipulations, as in other ruminants. In this review, the suckling period and digestive system development in newborn lambs are mentioned. Additionally, this review discusses some practices to manipulate intestinal development and microbial colonization in order to improve the production and health of newborn lambs at an early age when they are most susceptible to enteric diseases.
Design and performance analysis of an embedded amplified piezoelectric jetting dispensing valve
Authors: Yang Jingwei , Han Lintong , Wang Hongxin , Zhou Hongnan , Zhang Limin , He Lipeng
Published: September 2024

In order to satisfy the market’s demand for high-consistency, micro-dispensing of colloids, an embedded lever-amplified piezoelectric dispensing valve based on flexure hinge is designed. This structure has stable jetting performance, strong reliability, and can achieve micro-dispensing of medium and low viscosity glue. Theoretical analysis shows that the output displacement of the piezoelectric stack can meet the displacement requirement of dispensing after being amplified by this amplification mechanism. And the output displacement and mode of the amplification mechanism are calculated and analyzed by simulation. The rationality of the simulation model is verified by experiments, and the effect law of driving voltage, signal duty cycle and working frequency on the mass of glue droplets is obtained. The results show that under the conditions of driving voltage 100 V, duty cycle 50%, glue supply pressure 0.6 MPa, working frequency 100 Hz, the consistency deviation of single dispensing amount is ±2.01%, as a whole, 0.34–0.38 mg of uniform tiny glue dots can be obtained. The experimental results have verified the stability and micro-dispensing performance of the embedded lever amplification piezoelectric dispensing valve, providing reference for the subsequent application and research of jet dispensing.
Influence factors and improvement scheme on the breakdown behavior of pseudospark switch
Authors: Yuan Qi , Sun Guoxiang , Xue Haorui , Ding Weidong , Nie Shaohao , Yu Kunhao
Published: September 2024

High-power pulse generators are widely used in civil and military fields. The main switch directly determines the output characteristics of the high-power pulse generators, such as the voltage front time (t
f). Pseudospark switches (PSS) show a promising future for middle voltage, high repetitive frequency pulse power applications. However, how to further improve the breakdown behavior without reducing its advantages is a challenging task. In this paper, the influence of operating parameters (anode voltage U
A and gas pressure p) and structural parameter (number of cathode holes) on the breakdown behavior are investigated, the related mechanism are explained, and specific improvement schemes are proposed. It is found that the t
f of the single channel PSS (SCPSS) decreased significantly with increasing p, but hardly varied with U
A under moderate p. However, it is not a sound solution to increase the p excessively to reduce t
f. Besides, increasing the number of cathode holes can obtain a shorter t
f at low pressures (which implies superior repetition frequency performance). However, at 25 Pa, the jitter (which is defined as the standard deviation of t
f in multiple tests) of the 2-channel PSS is larger than that of the SCPSS. And the jitter of the 4-channel and 8-channel PSS is also greater than 6 ns and 2 ns, respectively. Through experimental and simulation analyses, it can be explained as the stepwise penetration of the virtual anode and the non-simultaneous ignition of the channels. A scheme to increase the trigger energy (ϵ) has been adopted to improve the simultaneous ignition probability, while shortening t
f and reducing jitter. After optimization, the good ignition probability of the 4-channel PSS has been improved to 82% and the jitter has been reduced to less than 1 ns at 25 Pa and 14.7 mJ.
Generation of GHz surface acoustic waves in (Sc,Al)N thin films grown on free-standing polycrystalline diamond wafers by plasma-assisted molecular beam epitaxy
Authors: Yuan Mingyun , Dinh Duc V , Mandal Soumen , Williams Oliver A , Chen Zhuohui , Brandt Oliver , Santos Paulo V
Published: September 2024

Telecommunication of the next generation demands filters that can operate in the 10 GHz range with sufficient bandwidths. For surface-acoustic-wave (SAW) devices this prerequisite translates into high sound velocities and high piezoelectric couplings. Wurtzite AlN on diamond, which exploits the strong piezoelectricity of AlN with the very high SAW velocity of diamond, has been considered a promising platform. A significant boost (up to a factor of 4) of the piezoelectric response can be obtained by alloying AlN with Sc. Here, the main challenge lies in the synthesis of highly-oriented thin (Sc,Al)N films on diamond. In this work, we aim at establishing a platform for SAW devices using plasma-assisted molecular beam epitaxy for the deposition of Sc0.2Al0.8N on diamond. We investigate the structural properties related to SAW generation gearing towards applications at high frequencies. To this end, we prepare (Sc,Al)N thin films on polished polycrystalline diamond wafers and demonstrate the efficient generation of SAW modes with frequencies up to 8 GHz. Systematic studies of the dependence of the SAW velocity and electromechanical coupling coefficient on the Sc0.2Al0.8N film thickness is presented for various SAW modes. Our result demonstrates the potential of this material combination for future application that requires large bandwidth in the ultra-high frequency range.
Coexistence of multiple magnetic interactions in oxygen-deficient V2O5 nanoparticles
Authors: Sarkar Tathagata , Biswas Soumya , Kakkar Sonali , Raghu A V , Kaushik S D , Bera Chandan , Kamble Vinayak B
Published: September 2024

This paper reports on the spin glass-like coexistence of competing magnetic orders in oxygen-deficient V2O5 nanoparticles having a broad size distribution. X-ray photoelectron spectroscopy yields the surface chemical stoichiometry of nearly V2O4.65 due to significant surface defect density. Temperature-dependent electrical conductivity and thermopower measurements demonstrate a polaronic conduction mechanism with a hopping energy of about 0.112 eV. The V2O5−δ
sample exhibits strong field as well as temperature-dependent magnetic behaviour when measured with a superconducting quantum interference device magnetometer, showing positive magnetic susceptibility across the temperature range of 2–350 K. Field-cooled and zero-field-cooled data indicate hysteresis, suggesting glassy behaviour. The formation of small polarons due to oxygen vacancy defects, compensated by V4+ charge defects, results in magneto-electronic phase separation (MEPS) and various magnetic exchanges, as predicted by first-principle calculations. This is evidenced by the strong hybridisation of V orbitals in the vicinity of vacant oxygen site. An increase in V4+ defects shows an antiferromagnetic (AFM) component in calculations. The magnetic diversity in undoped V2O4.9 originates from defect density and their random distribution, leading to MEPS. This involves localised spins in polarons and their ferromagnetic (FM) clusters on a paramagnetic (PM) background, while V4+ dimers induce AFM interactions. Electron paramagnetic resonance spectra measured at different temperatures indicate a dominant PM signal at a g-value of 1.97 due to oxygen defects, with a broad FM resonance-like hump. Both signals diminish with increasing temperature. Neutron diffraction (ND) data rules out long-range magnetic ordering, reflecting the composition as V2O4.886. Despite the FM hysteresis, no long-range order is observed in ND data, consistent with the polaron cluster-like FM with MEPS nature. This detailed study shall advance the understanding of the diverse magnetic behaviour observed in undoped non-magnetic systems.
Development of novel interferometric system for short and long gauge block calibration
Authors: Ahmed Khaled M , AlTalhh Yasser A , AlZamil Abdulhakim N , AlQahtani Nasser M
Published: September 2024

This paper presents the development of a novel multiwavelength Twyman–Green interferometer for gauge block (GB) calibration. In this work, a novel gauge block interferometer (GBI) for both short- and long-gauge block calibration at the SASO-NMCC was designed, built, tested, and described. The interferometer features an optomechanical modulation-based proprietary evaluation system, and the final length value was determined by applying Edlén’s equation to the refractive index of air. The developed interferometric system comprises two setups: one for short GB calibration, and the other for long GB calibration. The first short (GBI) setup utilizes two stabilized lasers, green and red, in vertical-mode operation. Another long GBI utilizes three stabilized lasers in the horizontal mode of operation. The primary characteristics of the interferometric system are explained. An uncertainty analysis with a careful study of the main components, such as wavelength standards, fringe fraction, temperature corrections, refractive index correction, obliquity correction, phase correction, block geometry correction, wavefront correction, and wringing correction, is presented. With interferometry, measurement method (ISO 3650 and ASME B89.1), using our described highly-precision horizontal mode system (GBI), we could achieve uncertainty level of ‘Q[49;0,28 l]nm l (mm)’ (k = 2) in the measurement range ‘125–1000 (mm)’. For the other system(GBI) for short gauge blocks, the associated uncertainty is ‘Q[30;0,27 l]nm l(mm)’ (k = 2) in the range of ‘0.5–100 (mm)’.
Underground concrete pipe crack damage monitoring by the fuzzy analysis of microseism
Authors: Tao Kai , Jiang Yaoxin
Published: September 2024

Underground concrete pipes are critical for the safety of urban infrastructure. Cracks could lead to accidents such as fluid spillage and ground subsidence, as well as waterlogging. Thus, it is of great significance to measure and monitor the crack of pipeline. In this study, a fuzzy monitoring method for concrete pipe crack damage based on the microseism signal Gaussian Mixed Model (GMM) analysis was proposed. First, the multiple parameters of the microseism signal were extracted. Then, Criteria Importance Through Intercriteria Correlation (CRITIC) weight vector was constructed using the importance information of parameters. Furthermore, the GMM membership matrix was created by the similarity of the probability density distribution. The crack condition was assessed by means of a fuzzy calculation between the weight vector and membership matrix. The experiment indicated that the proposed method can monitor and assess the different crack conditions in real time.
An improved YOLOv8-CGA-ASF-DBB method for multi-class wear debris recognition of online visual ferrograph image
Authors: Fan Bin , Wang Zhanyun , Feng Song , Wang Jindong , Peng Weigang
Published: September 2024

The analysis of wear based on on-line visual ferrograph provides crucial insights for the analysis of wear faults in mechanical equipment.However, online ferrograph analysis has been greatly limited by the low imaging quality and recognition accuracy of particle chains and high hubbles when analyzing lubricant oils in practical applications. To address this issue,this paper proposes an enhanced OLVF wear image detection model based on YOLOv8 and applies it to the multi-class intelligent recognition of ferrograph images .The cascade group attention module is introduced to enhance the diversity of features and improve computational efficiency. The attentional scale sequence fusion module is introduced to achieve precise and rapid recognition of small targets. This diverse branch block module is introduced efficiently to extracts features without compromising reasoning speed during training. For verification, a test of the bridge transmission box was conducted based on OLVF and 992 ferrograph images were collected. Experimental results reveal that the improved algorithm achieves an accuracy of 94.53% on the dataset of bridge transmission box ferrograph wear debris images collected through OLVF. This represents a 5.2% increase in recognition accuracy compared to the original algorithm while maintaining a processing time of only 0.69 ms per image. These findings provide compelling evidence for significant enhancements in both recognition accuracy and processing speed achieved by the improved algorithm, thereby establishing its considerable value for engineering applications.
The visual measurement method of the hole diameter and center-to-center distance of the box based on simplified external parameter calibration
Authors: Liu Siyuan , Wang Yanhao , Shao Tianchi , Miao Jianwei , Wang Conghui , Li Honglin , Pei Kai , Shao Junqi
Published: September 2024

The hole is a significant mechanical structure type. In this paper, two visual measurement models are established for chamfered and non-chamfered holes. A concentric cylinder with a known diameter is used as a calibration object to obtain the external parameters corresponding to the end face of the measured hole. This approach overcomes limitations associated with using calibration plates for external parameter calibration and aligns better with requirements in production sites. By utilizing the obtained external parameters, three-dimensional coordinates of edge points on the measured hole can be determined, and an ellipse fitting algorithm is employed to obtain aperture and center point coordinates. In the experiment, gearbox housing is used to measure hole diameter and center-to-center distance. The measurements are compared with a coordinate measuring machine, demonstrating a measurement accuracy up to 0.1 mm. The experimental results confirm both feasibility and effectiveness of measurement model while maintaining low operational complexity.
The linear swept sine method to determine the dispersion curve of structural pavement
Authors: Handayani Gunawan , Mabruri Hafidz
Published: September 2024

Pavement evaluation must be performed in nondestructive ways. This includes using the multichannel analysis of surface waves method by recording waves detected by multiple sensors from one active source. However, heavy traffic produces noise and reduces the detection quality as the sensor moves further away from the measurement source. We need a pavement evaluation method that is immune to noise. The linear swept-sine method presented in this paper has a very high resistance to noise by using a wide frequency band vibration source to the ground received by a single accelerometer at a small distance. The noise resistance is obtained by applying a tracking filter at the receiver (accelerometer), which accepts the signal with the frequency swept linearly at the same rate as the transmitter. This tracking filter has a low-frequency component equal to the phase delay between the source and the receiver, even when the transmitted source is generated in the high-frequency range. The dispersion curve is calculated and inverted by using the surface wave inversion method to obtain the velocity model below the pavement by calculating the delay for each data segment.
The ab initio study of n-type nitrogen and gallium co-doped diamond
Authors: Wang Zhen , Jin Peng , Qu Pengfei , Xu Dunzhou , Huo Xiaodi , Wu Ju , Wang Zhanguo
Published: September 2024

In order to better understand the influence of different complexes on the diamond co-doping system, N and Ga are chosen as co-dopants in diamond. The properties of several substitutional N
m
Ga
n

(
m
+
n
⩽
3
)

complexes with vacancy (Va) in the bulk diamond have been investigated by ab initio density functional technique, including their optimized lattice structures, formation energies, binding energies and thermodynamic transition levels. The calculational results show that N
m
Ga
n
complexes in the donor–acceptor–donor (DAD) configuration can provide ionization energies similar to phosphorus-doped diamond. All other complexes provide deep impurity levels. For the DAD configuration, the adsorption process on the diamond surface has been studied to demonstrate the feasibility of growing diamonds containing N-Ga-N in experiments. The desired complex configuration is not uniquely present in the co-doped system. Investigating these properties of different complexes beyond NGaN provides insight into the N and Ga codoped diamond system, yielding a more comprehensive understanding of its potential and limitations. Our research ideas can also be extended to other co-doped systems and help to evaluate other potential co-dopants for diamond.
Heat transport in SiCOH thin films: an experimental and molecular dynamics study
Authors: He Hu
Published: September 2024

Carbon-doped silicon dioxide (SiCOH) film is currently regarded as one of the most promising low-k materials in the integrated circuits (ICs) industry for advanced technology nodes. However, there have been limited studies on the thermal properties of SiCOH compared to its electrical and mechanical properties. In this study, we investigate the thermal conductivity of SiCOH thin films through molecular dynamics simulations (MD) and experimental characterizations. Our findings indicate that the size effect on thermal conductivity at 300 K is negligible when the thickness of SiCOH film is less than 20 nm. Additionally, we observe a contrasting temperature dependence law for the thermal conductivity of SiCOH thin films compared to crystal SiO2 thin films. Furthermore, we demonstrate a significant decrease in thermal conductivity with increasing porosity in SiCOH films; specifically, an increase in porosity from 5.35% to 42.77% results in a 60% reduction in thermal conductivity. Moreover, we validate our simulation results by characterizing the thermal conductivity of SiCOH using 3

ω

method.
An image encryption scheme based on an improved memristive neuron chaotic system
Authors: Wang Yanzhang
Published: September 2024

With fast-developing Internet and communication, the security transmission of image in network has become a research highlight. So far, researchers have designed a lot of image encryption methods based on chaotic models, some of them are not secure enough. To enhance security of image transmission on the network, in this paper, an image encryption method is developed from a 3D memeristive FitzHugh-Nagumo (FHN) neuron. First, a 3D memeristive FHN model is obtained by connecting a memeristor into a 2D FHN model, and dynamics for 3D FHN model are estimated by applying phase diagrams, bifurcation and Lyapunov exponent. Then, an image encryption algorithm is proposed by using this 3D model. Finally, security of encryption algorithm is estimated. Simulation results confirm the effectiveness of encryption scheme.
Utilizing quantum processor for the analysis of strongly correlated materials
Authors: Li Hengyue , Yang Yusheng , Lv Pin , Qu Jinglong , Wang Zhe-Hui , Sun Jian , Ying Shenggang
Published: September 2024

This study introduces a systematic approach for analyzing strongly correlated systems by adapting the conventional quantum cluster method to a quantum circuit model. We have developed a more concise formula for calculating the cluster’s Green’s function, requiring only real-number computations on the quantum circuit instead of complex ones. This approach is inherently more suited to quantum circuits, which primarily yield statistical probabilities. As an illustrative example, we explored the Hubbard model on a 2D lattice. The ground state was determined utilizing Xiaohong, a superconducting quantum processor equipped with 66 qubits, supplied by QuantumCTek Co., Ltd. Subsequently, we employed the circuit model with controllable noise to compute the real-time retarded Green’s function for the cluster, which is then used to determine the lattice Green’s function. We conducted an examination of the band structure in the insulator phase of the lattice system. This preliminary investigation lays the groundwork for exploring a wealth of innovative physics within the field of condensed matter physics.
Two-stage stochastic planning for distribution networks considering uncertainties of electric vehicles and distributed generators
Authors: Zheng Huhu , Ye Jianhua
Published: September 2024

A significant quantity of electric vehicles and distributed generator (DG) sources are connected to the distribution network (DN), resulting in the formation of a new power-transportation network (PTN). This integration introduces source-load uncertainty to the system. This research presents a stochastic planning model for PTN that focuses on making decisions on charging station locations. Initially, a model for the distribution network is created, which incorporates energy storage devices, demand response devices, and DG devices. The transportation network utilizes a P-median siting determination model. Ultimately, a two-stage stochastic planning approach is employed to address system uncertainty. The primary goal is to minimize both the investment cost and operation cost of the system while also considering several common situations. The efficacy of the proposed approach has been proven using a combined system consisting of a 33-node DN and a 25-node TN.
Optimal scheduling of virtual power plants considering integrated demand response
Authors: Wang Jinfeng , Wu Yulong , Wei Zhenze , Pang Jiale
Published: September 2024

In contemporary power system management, leveraging multilevel demand response strategies plays a pivotal role in balancing energy supply with demand, thereby enhancing system efficiency and flexibility. This paper introduces an innovative optimization model for virtual power plant operations that anticipates the scheduling needs several days in advance. It incorporates a comprehensive approach to demand response on the consumer side, highlighting two main types: price-based and substitution-based responses. Furthermore, the model integrates the functionalities of energy storage and conversion devices. This integration aims to facilitate effective load management, ensuring an optimized load distribution while minimizing the overall system costs.
Gear detection and research for hydraulic couplers based on AC electromagnetic field techniques
Authors: Han Yang , Liang Pengfei , Liu Xiaorui
Published: September 2024

To address the issue of fatigue cracks of hydraulic coupler gears in nuclear power plants, we construct an alternating current (AC) electromagnetic field detection system based on stress analysis of gear models. In this model, we design a probe suitable for gear detection in the main feedwater system of nuclear power plants. Moreover, artificial defects are machined into the gears to verify the feasibility of the AC electromagnetic techniques. Results indicate that the AC electromagnetic field techniques can detect the near-surface defects in the test piece with a greater detection depth and better detection effectiveness.
Analysis of hierarchical optimization control technology of distribution network with mobile energy storage
Authors: Lv Jiaolong , Gai Di , Liu Chuanbo , Bai Yuanlong , Zhang Mengyu , Han Yishu , Ma Shizhe , Ming Xin , Li Jialin , Xiao Ying
Published: September 2024

Mobile energy storage has many application scenarios and high scheduling flexibility. The article introduces the layered optimization control technology of distribution networks to ensure the safety of distribution network operation after mobile energy storage access. The article analyzes the logic principle of distribution network hierarchical control technology, constructs a distribution network hierarchical optimization control model, and introduces the solution algorithm of the optimization model. The case study findings indicate that the examined layered control strategy for distribution networks can appropriately manage the charge and discharge states of mobile energy storage. This enhances the utility of mobile energy storage and the operational dependability of the distribution network.