bluuebunny/crossref_metadata_2025 huggingface dataset:
Microcalorimetry reveals multi-state thermal denaturation of G. stearothermophilus tryptophanyl-tRNA synthetase
Authors: Chandrasekaran Srinivas Niranj , Das Jhuma , Dokholyan Nikolay V. , Carter Charles W.
Published: July 2023

Mechanistic studies of Geobacillus stearothermophilus tryptophanyl-tRNA synthetase (TrpRS) afford an unusually detailed description—the escapement mechanism—for the distinct steps coupling catalysis to domain motion, efficiently converting the free energy of ATP hydrolysis into biologically useful alternative forms of information and work. Further elucidation of the escapement mechanism requires understanding thermodynamic linkages between domain configuration and conformational stability. To that end, we compare experimental thermal melting of fully liganded and apo TrpRS with a computational simulation of the melting of its fully liganded form. The simulation also provides important structural cameos at successively higher temperatures, enabling more confident interpretation. Experimental and simulated melting both proceed through a succession of three transitions at successively higher temperature. The low-temperature transition occurs at approximately the growth temperature of the organism and so may be functionally relevant but remains too subtle to characterize structurally. Structural metrics from the simulation imply that the two higher-temperature transitions entail forming a molten globular state followed by unfolding of secondary structures. Ligands that stabilize the enzyme in a pre-transition (PreTS) state compress the temperature range over which these transitions occur and sharpen the transitions to the molten globule and fully denatured states, while broadening the low-temperature transition. The experimental enthalpy changes provide a key parameter necessary to convert changes in melting temperature of combinatorial mutants into mutationally induced conformational free energy changes. The TrpRS urzyme, an excerpted model representing an early ancestral form, containing virtually the entire catalytic apparatus, remains largely intact at the highest simulated temperatures.
Sequences of trees and higher-order renormalization group equations
Authors: Dugan William T. , Foissy Loïc , Yeats Karen
Published: July 2023

We define a notion of higher-order renormalization group equations and investigate when a sequence of trees satisfies such an equation. In the strongest sense, the sequence of trees satisfies a kth-order renormalization group equation when applying any choice of Feynman rules results in a Green function satisfying a kth-order renormalization group equation, and we characterize all such sequences of trees. We also make some comments on sequences of trees, which require special choices of Feynman rules in order to satisfy a higher-order renormalization group equation.
The synchronizing role of multiplexing noise: Exploring Kuramoto oscillators and breathing chimeras
Authors: Phillips Ewan T.
Published: July 2023

The synchronization of spatiotemporal patterns in a two-layer multiplex network of identical Kuramoto phase oscillators is studied, where each layer is a non-locally coupled ring. Particular focus is on the role played by a noisy inter-layer communication. It is shown that modulating the inter-layer coupling strength by uncommon noise has a significant impact on the dynamics of the network, in particular, that modulating the interlayer coupling by noise can counter-intuitively induce synchronization in networks. It is further shown that increasing the noise intensity has many other analogous effects to that of increasing the interlayer coupling strength. For example, the noise intensity can also induce state transitions in a similar way, in some cases causing the layers to completely synchronize within themselves. It is discussed how such disturbances may in many cases be beneficial to multilayer systems. These effects are demonstrated both for white noise and for other kinds of colored noise. A “floating” breathing chimera state is also discovered in this system.
Methods of controlled formation of instabilities during the electrical explosion of thin foils
Authors: Shelkovenko T. A. , Tilikin I. N. , Oginov A. V. , Mingaleev A. R. , Romanova V. M. , Pikuz S. A.
Published: July 2023

The results of a study of the electrical explosion of aluminum foils with an artificial periodic surface structure created by laser engraving are presented. Experiments were carried out on pulsed high-current generators BIN (270 kA, 300 kV, 100 ns) and KING (200 kA, 40 kV, 200 ns) with Al foil of thicknesses 16 and 4 μm, respectively. Images of the exploded foils were recorded by point projection radiography in the radiation from hybrid X-pinches. It is found that the application of an artificial periodic structure to the foil leads to a much more uniform and well-defined periodic structure of the exploded foil. Images recorded in the UV range using a microchannel-plate-intensified detector show that the radiation from a surface-modified foil is more uniform along the entire length and width of the foil than that from a foil without modification.
Head-on collision of large-scale high density plasmas jets: A first-principle kinetic simulation approach
Authors: Wu D. , Zhang J.
Published: July 2023

In the double-cone ignition (DCI) inertial confinement fusion (ICF) scheme, head-on collision of high density plasma jets is one of the most distinguished feature when compared with the traditional central ignition and fast ignition of ICF. However, the application of traditional hydrodynamic simulation methods becomes limited, due to serious plasma penetrations, mixing, and kinetic physics that might occur in the collision process. To overcome such limitations, we propose a new simulation method for large-scale high density plasmas. This method takes advantages of modern particle-in-cell simulation techniques and binary Monte Carlo collisions, including both long-range collective electromagnetic fields and short-range particle–particle interactions. Especially, in this method, the restrictions of simulation grid size and time step, which usually appear in a fully kinetic description, are eliminated. In addition, collisional coupling and state-dependent coefficients, which are usually approximately used with different forms in fluid descriptions, are also removed in this method. Energy and momentum exchanges among particles and species, such as thermal conductions and frictions, are modeled by “first principles” kinetic approaches. The correctness and robustness of the new simulation method are verified, by comparing with fully kinetic simulations at small scales and purely hydrodynamic simulations at large scale. Following the conceptual design of the DCI scheme, the colliding process of two plasma jets with initial density of 100 g/cc, initial thermal temperature of 65 eV, and counter-propagating velocity at 300 km/s is investigated using this new simulation method. Quantitative values, including density increment, increased plasma temperature, confinement time at stagnation, and conversion efficiency from the colliding kinetic energy to thermal energy, are obtained with a density increment of about three times, plasma temperature of 400 eV, confinement time at stagnation of 50 ps, and conversion efficiency of 85%. These values agree with the recent experimental measurements at a reasonable range.
Chemotaxis-driven stationary and oscillatory patterns in a diffusive HIV-1 model with CTL immune response and general sensitivity
Authors: Han Renji , Dai Binxiang , Chen Yuming
Published: July 2023

In this paper, a reaction–diffusion–chemotaxis HIV-1 model with a cytotoxic T lymphocyte (CTL) immune response and general sensitivity is investigated. We first prove the global classical solvability and L∞-boundedness for the considered model in a bounded domain with arbitrary spatial dimensions, which extends the previous existing results. Then, we apply the global existence result to the case with a linear proliferation immune response and an incidence rate. We study the spatiotemporal dynamics about the three types of spatially homogeneous steady states: infection-free steady state S0, CTL-inactivated infection steady state S1, and CTL-activated infection steady state S∗. Our analyses indicate that S0 is globally asymptotically stable if the basic reproduction number R0 is less than 1; if R0 is between 1 and a threshold, then S1 is globally asymptotically stable. However, if R0 is larger than the threshold, then the chemoattraction and chemorepulsion can destabilize S∗, and thus, a spatiotemporal pattern forms as the chemotactic sensitivity crosses certain critical values. We obtain two kinds of important patterns, which are induced by chemotaxis: stationary Turing pattern and irregular oscillatory pattern. We also find that different chemotactic response functions can affect system’s dynamics. Based on some empirical parameter values, numerical simulations are given to illustrate the effectiveness of the theoretical predications.
The effects of electron energy distribution and ionization cross section uncertainty on charge breeder ion source diagnostics with pulsed 1+ injection
Authors: Luntinen M. , Angot J. , Koivisto H. , Tarvainen O. , Thuillier T. , Toivanen V.
Published: July 2023

The consecutive transients (CT) method is a plasma diagnostic technique of charge breeder electron cyclotron resonance ion source plasmas. It is based on the short-pulse injection of singly charged ions and the measurement of the resulting transients of the extracted multi-charged ion beams. Here, we study the origin of the large uncertainty bounds yielded by the method to reveal avenues to improve its accuracy. We investigate effects of the assumed electron energy distribution (EED) and the uncertainty inherited from the ionization cross section data of K4+–K12+ ions on the resulting plasma electron density ne, average energy ⟨Ee⟩, and the characteristic times of ion confinement τq, electron impact ionization τinzq, and charge exchange τcxq provided by the CT method. The role of the EED was probed with Kappa and double-Maxwellian distributions, the latter resulting in a shift of the ne and ⟨Ee⟩ distributions. The uncertainty of the ionization cross section σq→q+1inz was artificially curtailed to investigate its impact on values and uncertainties of the plasma parameters. It is demonstrated that the hypothetical perfect knowledge of σq→q+1inz significantly reduces the uncertainties of τq, τinzq, and τcxq, which motivates the need for improved cross section data.
Recognition of bovine hemoglobin protein on molecularly imprinted polymer surfaces using nonlinear vibrational spectroscopy
Authors: Chaudhary Shilpi , Kaur Harsharan , Kaur Harpreet , Jena Kailash C.
Published: July 2023

Advancement in molecularly imprinted biomimetics has aided in developing robust artificial recognition-based materials, which can be customized for bio/chemo-sensing of distinct molecules. The present study reports a simple one-step synthesis and analysis of protein-imprinted polymer thin films as a recognition element directly onto a solid support. Dopamine has been explored as a versatile functional monomer for a molecularly imprinted polymer (MIP) matrix to fabricate polydopamine (PDA) thin films with bovine hemoglobin as a template protein molecule. A detailed molecular-level insight into the recognition of the template molecule at each step has been investigated using vibrational sum frequency generation (VSFG) spectroscopy. A suitable PDA-coated thin film is selected based on the extent of polymerized intermediates formed after non-imprinted polymer fabrication at different time durations. An optimally prepared film of MIP is specified by observing the spectral signature of the methyl groups from protein molecules at the air–polymer interface. The template removal from MIP films after the washing procedure and subsequent re-binding of the protein molecules were evaluated by VSFG spectroscopy. The insightful molecular-level findings from SFG spectroscopy demonstrate the fabrication of an imprinted matrix as a label-free chemical sensor.
Study of red blood cells and particles in stenosed microvessels using coupled discrete and continuous forcing immersed boundary methods
Authors: Yoon Daegeun , Mishra Rahul , You Donghyun
Published: July 2023

A computational study of the blood flow in a stenosed microvessel is presented using coupled discrete ghost-cell and continuous-forcing immersed boundary methods. This study focuses on studying platelet behaviors near the stenosis with deformable red blood cells (RBCs). The influence of varying hematocrit, area blockage, stenosis shape, and driving force on flow characteristics, RBCs, and particle behaviors is considered. Distinct flow characteristics are observed in stenosed microvessels in the presence of RBCs. The motion of RBCs is the major cause of time-dependent oscillations in flow rates, while the contribution of particles to the fluctuations is negligible. However, this effect decreases when the stenosis is elongated in the axial direction. Interestingly, as the hematocrit level increases, downstream particles move closer to the vessel wall due to the enhanced shear-induced lift force resulting from the interaction among RBCs and particles. Furthermore, it is observed that geometrical changes in the stenosis have a more significant impact on the axial profile of particle concentration compared to changes in hematocrit or driving force. An asymmetric stenosis leads to asymmetric profiles in the flow velocity and the distribution of cells and particles due to the geometric focusing effect of the stenosis. There is no significant change in flow rates until a blockage of 0%–50%, but a sudden increase in the root mean square of flow rates occurs at an 80% blockage. This study contributes to our understanding of the rheological behaviors of RBCs and rigid particles in a stenosed microvessel under various hemodynamic conditions.
Selective activation of topological valley corner states in C3-symmetric photonic crystals
Authors: He Jiangle , Jia Shiyin , Li Yaxuan , Hu Junzheng , Huang Renwen , Su Guangxu , Lu Minghui , Zhan Peng , Liu Fanxin
Published: July 2023

Higher-order topological insulators have drawn great research attention in nanophotonics due to their ability to both support robust edge states and lower dimensional corner states. In this work, we present a theoretical proposal for achieving topologically switchable and valley-selective corner states based on two-dimensional C3-symmetric photonic crystals (PCs), with breaking of inversion symmetry. Through the concatenation of two valley PCs with contrasting topological indices, we demonstrate the emergence of two types of valley-locked chiral topological edge states resulting from the valley–valley interaction. More importantly, we find that the system exhibits two distinct types of corner states, characterized by strong robustness and high localization, when the PCs are spliced at a 60° angle. However, the corner states are absent when the splicing angle is set as 120°. According to the theoretical analysis, the selective activation of topological valley corner states is related to the sign flip of valley Chern number at the corner. Based on this feature, we further propose a topological photonic switching device, in which the corner can be lighted up or off selectively. By combining the benefits of higher-order topology and valley degree of freedom, our work provides an efficient and flexible method for light manipulation.
On the reductions of airfoil–turbulence noise by curved wavy serrations
Authors: Singh Sushil Kumar , Narayanan S.
Published: July 2023

The present study provides an extensive experimental investigation into the use of curved sinusoidal (or wavy) trailing-edge (TE) serrations as a passive means for augmenting the airfoil broadband noise reduction over a broad range of frequencies. The curved sinusoidal TE serrated airfoils with parameters i = 20°, h/Co = 0.167, λ/Co = 0.134, and R/Co = 0.334 provide significant noise reduction benefits of about 4 dB with respect to the wider uniform serrations (i.e., λ/Co = 0.2), particularly from mid- to high-frequency ranges, where i, Co, h, λ, and R are the inclination angle, mean chord, serration amplitude, serration wavelength, and radius of curvature, respectively. Also, they provide an additional noise reduction of about 2.5 dB with respect to the narrow uniform serrations (i.e., λ/Co = 0.033), particularly from mid- to high-frequency ranges. On the whole, the curved sinusoidal TE serrations having an inclination angle of i = 15° and i = 20° could offer an average additional noise reduction benefit of about 1 and 2 dB for the range of frequencies from 1 to 10 kHz at all jet velocities. The normalized sound reduction (ΔPWL′) provided by the curved sinusoidal TE serrated airfoils show linear dependence with the modified Strouhal number for all jet speeds. Furthermore, the sound power reduction performance provided by curved sinusoidal TE serrations follows a modified Strouhal number scaling law from mid- to high-frequency ranges, which indicates their universal behavior on the noise reduction performance. The flow near the TE of the curved sinusoidal TE serrated airfoil undergoes multiple breakups, thus leading to non-uniform acoustic radiation throughout the span. The flow structures along the curvature undergo large-scale disintegration due to the presence of the inclination section in the curved sinusoidal TE serration. Thus, the granular structure of the turbulent eddies is fragmented into the fine length scales due to the presence of multiple breakups near the TE of the curved wavy serrations. Furthermore, the inclined portion of the curved wavy TE serration increases the disruption of the vortex shedding and reduces the velocity fluctuations, which reduces the surface pressure fluctuations close to the TE and, hence, the far-field noise.
Symmetry groupoids for pattern-selective feedback stabilization of the Chafee–Infante equation
Authors: Schneider I. , Dai J.-Y.
Published: July 2023

Reaction–diffusion equations are ubiquitous in various scientific domains and their patterns represent a fascinating area of investigation. However, many of these patterns are unstable and, therefore, challenging to observe. To overcome this limitation, we present new noninvasive feedback controls based on symmetry groupoids. As a concrete example, we employ these controls to selectively stabilize unstable equilibria of the Chafee–Infante equation under Dirichlet boundary conditions on the interval. Unlike conventional reflection-based control schemes, our approach incorporates additional symmetries that enable us to design new convolution controls for stabilization. By demonstrating the efficacy of our method, we provide a new tool for investigating and controlling systems with unstable patterns, with potential implications for a wide range of scientific disciplines.
Numerical simulation of modified nonlinear Schrodinger equation and turbulence generation
Authors: Kumar Praveen , Nandal P. , Uma R. , Sharma R. P.
Published: July 2023

This article presents a numerical model to study wave turbulence in fluids. The model equation is derived by incorporating energy conservation (along with the usual fluid equations of a compressible flow), and the source of nonlinearity is the rise in temperature due to the acoustic wave's high amplitude. The nonlinear Schrödinger (NLS) and modified nonlinear Schrödinger (MNLS) equations have been derived and then solved numerically. A numerical simulation of the MNLS equation is used for investigating the turbulence generation and a semi-analytical method to understand the physics of localized structures of nonlinear waves. The numerical simulation is based on a pseudo-spectral approach to resolve spatial regimes, a finite difference method for temporal evolution. The results show a periodic pattern viz. Fermi–Pasta–Ulam (FPU) recurrence for NLS, while turbulence generation breaks down the FPU recurrence in MNLS. The turbulent power spectrum in the inertial sub-range approximately follows the Kolmogorov–Zakharov scaling (∼k−1.2).
Effects of shear-thinning rheological properties on the energy loss characteristics of a biomass mixing vessel
Authors: Zheng Zhi , Wang Peng , He Naihu , Si Qiaorui , Li Guidong , Du Daolin , Yuan Jianpin
Published: July 2023

This study investigated the irreversible energy losses in the different sections of propeller blades. To the best of our knowledge, this is the first study to consider the properties of a shear-thinning fluid in evaluating irreversible energy losses based on the entropy generation theory. The numerical simulation results were consistent with the experimental results. The flow energy losses and the total mechanical energy loss gradient of an anaerobic digestion (AD) system were determined. The results indicated that the total mechanical energy loss occurred in the propeller region and was primarily influenced by the operation speed. The effects of rheology were neglected, although rheology notably affects the equivalent-volume velocity field within specific power characteristics, leading to an insufficient mixing field in the AD system. The energy losses primarily occurred around the propeller region, primarily in sections 3–5 under different flow rates. Viscous diffusion and velocity fluctuation are the primary factors contributing to the entropy of the system, accounting for more than 98%. According to the wall separation and friction loss on the suction and pressure surfaces of the propellers, sections 3–5 accounted for 90% of the energy loss. Energy dissipation in the propeller was mostly constituted by turbulence entropy and direct entropy. The rotation speed was the key factor causing viscous diffusion. Although the rheology effect on hydraulic loss is limited at low concentrations, the hydraulic loss in the blade tip region due to high-concentration fluids is significantly affected by rheology.
Pinched hysteresis loop and internal bias field in Ba4(La0.2Nd0.2Sm0.2Eu0.2Y0.2)2Ti4Nb6O30 tungsten bronze ceramics
Authors: Wang Ying , Zhu Xiao Li , Wu Shu Ya , Liu Xiao Qiang , Chen Xiang Ming
Published: July 2023

A-site high entropy Ba4(La0.2Nd0.2Sm0.2Eu0.2Y0.2)2Ti4Nb6O30 tungsten bronze ceramics were designed and prepared by a standard solid state sintering process. First-order ferroelectric transition occurs around 240 °C on heating, while around 136 °C on cooling. Pinched and asymmetric P–E hysteresis loops were observed within and below the thermal hysteresis temperature range of the ferroelectric transition. Pinched P–E hysteresis loops were attributed to the coupling between the ferroelectric transition and the commensurate/incommensurate modulation transition. The reason for the asymmetry of the hysteresis loop was the presence of an internal bias electric field. Different measuring procedures were designed to clarify the evolution of hysteresis loop asymmetry. The existence of oxygen vacancy and Eu3+/Eu2+ was identified by x-ray photoemission spectroscopy. The electric field cycling with elevated temperatures caused defect dipoles incline to align along the direction of spontaneous polarization leading to the internal bias electric field. Due to the A-site high entropy effect, dielectric strength of Ba4(La0.2Nd0.2Sm0.2Eu0.2Y0.2)2Ti4Nb6O30 ceramics is up to 300 kV/cm, which is increased by more than 50% than that with the single element in the A1-site.
Improved performance and stability in CH3NH3PbI3/Si heterojunction photodetectors realized by ZIF-67 additive assisted Co ion doping
Authors: Cheng Peiyu , Qiu Jing , Zhao Tong , Wang Yuling , Chen Mingming , Zhang Huimin , Liu Yuan , Cao Dawei , Dong Xiuxiu , Wang Quan
Published: July 2023

Lead halide perovskites have been regarded as promising materials for fabrication of high-performance photodetectors (PDs). However, spin-coated perovskite thin films generally have suffered from high-density grain boundaries and defect states, which severely deteriorated the performance and stability of resulting PDs. Fortunately, the above issues can be effectively solved via additive assisted metal ions doping. In this work, Co-based zeolite imidazole framework (ZIF-67) additive assisted Co ion doping has been proposed to prepare high-quality perovskite CH3NH3PbI3 (MAPbI3) thin films. Morphological, structural, optical, and electrical studies have shown that Co ion doping decreased grain boundaries as well as suppressed defect states, which greatly enhanced the performance and stability of MAPbI3/Si heterojunction PDs, including reducing dark current, increasing photocurrent, and increasing response speed. Finally, the mechanisms of suppression of defect states benefiting from Co ion doping were discussed based on density functional theory calculations. The results provided in this work will pave the way for development of high-performance and stable MAPbI3 PDs in the future.
DMD-based single-pixel off-axis interferometry for wavefront reconstruction of a biological sample
Authors: Du Zhiheng , Zhao Wenjing , Zhai Aiping , Zhang Zhaoxia , Wang Dong
Published: July 2023

Single-pixel detecting is suitable for wavefront reconstruction in some special wavelengths where array detectors are immature or even unavailable and/or under low light conditions. However, most of the demonstrations are generally realized by multi-step phase-shifting interferometry with a liquid crystal spatial light modulator (LC-SLM) that has a slow modulation speed, which limits the reconstruction speed, thus restricting practical applications of the technique. Here, we propose to use a digital-micromirror-device-(DMD)-based single-pixel off-axis common-path interferometry (SOCI) for faster wavefront reconstruction. The method utilizes passive detection based on the DMD to realize SOCI for accelerating wavefront reconstruction. As compared to the LC-SLM-based phase-shifting techniques, since the modulation speed of the DMD is hundreds of times faster than that of the LC-SLM, the DMD-based SOCI accelerates several folds of reconstruction speed further, which, thus, makes the final wavefront reconstruction three orders of magnitude faster. The effectiveness and advantages of our method are experimentally demonstrated by quantitatively reconstructing the amplitude and phase images of a biological sample.
Evaluation of stenosis and hematocrit for platelet activation and plaque injury in atherosclerosis blood vessels
Authors: Zhang Xuelan , Liu Chen , Zhu Jing , Luo Mingyao , Si Xinhui , Shu Chang
Published: July 2023

Atherosclerosis of lower extremity is often accompanied by thrombosis and plaque injury. Currently, there is a lack of comprehensive hemodynamics study that combines platelet activation related to thrombosis and plaque injury in atherosclerosis. Thus, we first analyze the mechanism of platelet activation and plaque injury and further investigate the effects of stenosis and hematocrit through hemodynamic results. An Euler–Euler method is used for the mixed fluid containing red blood cells (RBCs) coupled with a Lagrangian approach for the transport of plasma particles. To more realistically implement this mathematical model, we employ user-defined functions to incorporate platelet level of activation (LOA), vessel specific Windkessel model, RBCs form factor, and platelet form factor into the simulation calculation framework. Our results suggest that in a narrow larynx, high wall shear stress activates platelets. Subsequently, platelets accumulate downstream of the stenosis due to the reflux caused by the stenosis or hyperviscous blood stasis on account of increased hematocrit. The stenosis rises from 0.00% to 70.01%, or the hematocrit from 0.55 to 0.65, and increases LOA by 5.00% or 34.41%, respectively, in conclusion high stenosis and high hematocrit predispose to thrombosis and plaque injury. Therefore, it is necessary to regularly check the degree of stenosis in patients with atherosclerosis, especially in those with high hematocrit caused by related disease. The results obtained could provide a theoretical basis for the diagnosis and treatment of lower limb atherosclerosis.
360° detection of linear ZnO@CFs photoelectrochemical-type ultraviolet photodetector
Authors: Zhang Xinmiao , Ji Fanbo , Wang Gang , Li Jiang , Jin Mengjing , Zhou Jinyuan , Xie Erqing , Pan Xiaojun
Published: July 2023

Applications of omnidirectional ultraviolet (UV) detectors are numerous and promising. There is an increasing demand for flexible UV detectors toward the realization of intelligent and weavable systems. Carbon fibers (CFs) are used in flexible omnidirectional UV detectors due to their linear structure and unique flexibility. In this work, a flexible photoanode for omnidirectional photoelectrochemical (PEC)-type UV photodetectors (PDs) based on wurtzite hexagonal-phase ZnO nanowires grown on CFs is developed. The PD based on ZnO@CFs has a good response for rotation angles in the range from 0° to 360°. After being bent and twisted several hundred times, the PD still exhibits a stable switching period. Furthermore, the detector shows stable photocurrents up to 185 μA cm−2, reproducible switching periods, fast rising and falling response times of 0.17 and 0.12 s, respectively, and excellent spectral selectivity of 300–400 nm. The proposed flexible photoanode has potential applications in wearable PEC UV detectors with 360° detection.
Scalable wavelength-multiplexing photonic reservoir computing
Authors: Li Rui-Qian , Shen Yi-Wei , Lin Bao-De , Yu Jingyi , He Xuming , Wang Cheng
Published: July 2023

Photonic reservoir computing (PRC) is a special hardware recurrent neural network, which is featured with fast training speed and low training cost. This work shows a wavelength-multiplexing PRC architecture, taking advantage of the numerous longitudinal modes in a Fabry–Perot (FP) semiconductor laser. These modes construct connected physical neurons in parallel, while an optical feedback loop provides interactive virtual neurons in series. We experimentally demonstrate a four-channel wavelength-multiplexing PRC architecture with a total of 80 neurons. The clock rate of the multiplexing PRC reaches as high as 1.0 GHz, which is four times higher than that of the single-channel case. In addition, it is proved that the multiplexing PRC exhibits a superior performance on the task of signal equalization in an optical fiber communication link. This improved performance is owing to the rich neuron interconnections both in parallel and in series. In particular, this scheme is highly scalable owing to the rich mode resources in FP lasers.
Advancements in nearshore wave modeling: A unified one-layer nonhydrostatic approach
Authors: Wang Hang , Wang Gang , Zheng Jinhai , Liang Qiuhua , Tao Aifeng
Published: July 2023

This work presents a novel one-layer nonhydrostatic formulation and model for nearshore waves. The proposed governing equations define velocities and pressures at arbitrary distances from the still water and only contain spatial derivatives of maximum second order. The formulation can be unified into the existing nonhydrostatic models by defining the variables at the middle depth and neglecting certain additional terms. A Stokes-type Fourier analysis was performed to analyze the formulations' properties and determine the location of variables. The proposed formulation exhibited a clear superiority in describing both the linear and nonlinear properties of the coastal waves. The equations were numerically solved using a hybrid-finite, volume-finite difference scheme. The resulting model accurately described the wave-breaking and runup processes that occurred due to the adoption of a shock-capturing scheme and seabed elevation reconstruction. The suggested novel numerical model was validated against two theoretical benchmark tests and three wave transformation experiments.
Dynamic changes and importance of plasma concentrations of ether phospholipids, of which the majority are plasmalogens, in postpartum Holstein dairy cows
Authors: Saito Risa , Kubo Tomoaki , Wakatsuki Takuji , Asato Yuuki , Tanigawa Tamako , Kotaniguchi Miyako , Hashimoto Maki , Kitamura Shinichi , Kadokawa Hiroya
Published: July 2023

Context Ethanolamine plasmalogens (EPls) and choline plasmalogens (CPls) are classes of ethanolamine ether phospholipids (ePE) and choline ether phospholipids (ePC), respectively. EPls play crucial roles in maternal and breastfed infant bodies and stimulate gonadotropin secretion by gonadotrophs. Aims To estimate changes in and importance of plasma concentrations of EPls and CPls, utilising newly developed enzymatic fluorometric assays for ePE and ePC in postpartum Holstein cows. Methods Plasma samples were collected from 3 weeks before expected parturition until approximately 8 weeks after parturition (16 primiparous and 38 multiparous cows) for analysis. Key results Plasma concentrations of ePE and ePC, most of which are plasmalogens, declined before and increased after parturition and stabilised near the day of the first postpartum ovulation (1stOV). From weeks 2 to 3 after parturition, third-parity cows exhibited ePE concentrations that were higher than those of other parity cows. The days from parturition to 1stOV correlated with days from parturition to conception. On the day of 1stOV, milk yield correlated with plasma concentration of both ePE and ePC, while ePC concentration correlated negatively with milk fat percentage. At the early luteal phase after 1stOV, plasma ePE concentration correlated with plasma anti-Müllerian hormone concentration (r = 0.39, P < 0.01), and plasma ePC concentration correlated with plasma follicle-stimulating hormone concentration (r = 0.43, P < 0.01). Conclusion The concentrations of ePE and ePC changed dramatically around parturition and 1stOV, and the concentrations correlated with important parameters for milk production and reproduction. Implications The blood plasmalogen may play important roles in postpartum dairy cows.
Two different jumping mechanisms of water striders are determined by body size
Authors: Kim Woojoo , Amauger Juliette , Ha Jungmoon , Pham Thai Hong , Tran Anh Duc , Lee Jae Hong , Park Jinseok , Jablonski Piotr G. , Kim Ho-Young , Lee Sang-im
Published: July 2023

Current theory for surface tension-dominant jumps on water, created for small- and medium-sized water strider species and used in bioinspired engineering, predicts that jumping individuals are able to match their downward leg movement speed to their size and morphology such that they maximize the takeoff speed and minimize the takeoff delay without breaking the water surface. Here, we use empirical observations and theoretical modeling to show that large species (heavier than ~80 mg) could theoretically perform the surface-dominated jumps according to the existing model, but they do not conform to its predictions, and switch to using surface-breaking jumps in order to achieve jumping performance sufficient for evading attacks from underwater predators. This illustrates how natural selection for avoiding predators may break the theoretical scaling relationship between prey size and its jumping performance within one physical mechanism, leading to an evolutionary shift to another mechanism that provides protection from attacking predators. Hence, the results are consistent with a general idea: Natural selection for the maintenance of adaptive function of a specific behavior performed within environmental physical constraints leads to size-specific shift to behaviors that use a new physical mechanism that secure the adaptive function.
Modulation of inner junction proteins contributes to axoneme differentiation
Authors: Chen Zhe , Li Ming , Zhu Hao , Ou Guangshuo
Published: July 2023

Cilia build distinct subdomains with variable axonemal structures to perform diverse functions in cell motility and signaling. In sensory cilia across species, an axoneme differentiates longitudinally into a middle segment with nine microtubule (MT) doublets and a distal segment with nine MT singlets that extends from the A tubules of the doublets. Here, we study axoneme differentiation in
Caenorhabditis elegans
by analyzing the flagellar inner junction protein FAP20 and PCRG1 that connect A and B tubules in
Chlamydomonas
. The nematode CFAP-20 is restricted to the middle segment with doublets, and its loss disconnects A and B tubules. However, PCRG-1 is absent from most sensory cilia, and its deletion does not disrupt cilia. Ectopic introduction of PCRG-1 into cilia generated abnormal MT doublets in the distal segment and reduced intraflagellar transport and animal sensation. Thus, the absence of an inner junction protein prevents B-tubule extension, which contributes to axoneme differentiation and ciliary function.
T cell deletional tolerance restricts AQP4 but not MOG CNS autoimmunity
Authors: Sagan Sharon A. , Moinfar Zahra , Moseley Carson E. , Dandekar Ravi , Spencer Collin M. , Verkman Alan S. , Ottersen Ole Petter , Sobel Raymond A. , Sidney John , Sette Alessandro , Anderson Mark S. , Steinman Lawrence , Wilson Michael R. , Sabatino Joseph J. , Zamvil Scott S.
Published: July 2023

Aquaporin-4 (AQP4)-specific Th17 cells are thought to have a central role in neuromyelitis optica (NMO) pathogenesis. When modeling NMO, only AQP4-reactive Th17 cells from AQP4-deficient (AQP4
−/−
), but not wild-type (WT) mice, caused CNS autoimmunity in recipient WT mice, indicating that a tightly regulated mechanism normally ensures tolerance to AQP4. Here, we found that pathogenic AQP4 T cell epitopes bind MHC II with exceptionally high affinity. Examination of T cell receptor (TCR) α/β usage revealed that AQP4-specific T cells from AQP4
−/−
mice employed a distinct TCR repertoire and exhibited clonal expansion. Selective thymic AQP4 deficiency did not fully restore AQP4-reactive T cells, demonstrating that thymic negative selection alone did not account for AQP4-specific tolerance in WT mice. Indeed, AQP4-specific Th17 cells caused paralysis in recipient WT or B cell-deficient mice, which was followed by complete recovery that was associated with apoptosis of donor T cells. However, donor AQP4-reactive T cells survived and caused persistent paralysis in recipient mice deficient in both T and B cells or mice lacking T cells only. Thus, AQP4 CNS autoimmunity was limited by T cell–dependent deletion of AQP4-reactive T cells. In contrast, myelin oligodendrocyte glycoprotein (MOG)-specific T cells survived and caused sustained disease in WT mice. These findings underscore the importance of peripheral T cell deletional tolerance to AQP4, which may be relevant to understanding the balance of AQP4-reactive T cells in health and in NMO. T cell tolerance to AQP4, expressed in multiple tissues, is distinct from tolerance to MOG, an autoantigen restricted in its expression.
Magnetic anisotropy and planar topological Hall effect in SrMn
x
Ir1−
x
O3 films
Authors: Hou Pengxiang , Li Yao , Liu Zhiyu , Zhang Chenyu , Han Yajie , Xi Zhongnan , Li Jiayi , Li Man-Rong , Deng Yu , Yang Yurong , Hu Yong , Wu Di
Published: July 2023

Strong Coulomb repulsion and spin–orbit coupling are known to give rise to exotic physical phenomena in transition metal oxides. Here, we report magnetic and transport characteristics of (001) oriented epitaxial SrMn
x
Ir1−x
O3 thin films, having both 3d and 5d elements on the perovskite B sites. With the increase of Mn concentration, perpendicular magnetic anisotropy (PMA) decreases gradually in accompany with the magnetic easy axis tilting away from the out-of-plane [001] direction. X-ray absorption spectroscopy reveals that Mn e
g electrons preferentially occupy the

d

3

z

2

−

r

2

orbital, which produces the observed PMA in the framework of spin-orbital coupling. A planar topological Hall effect appears in SrMn
x
Ir1−x
O3 films with x about 0.30 when the magnetic field is applied along the current, which is a result of the noncoplanar spin structure due to the competition among the PMA, the magnetic exchange interaction and the Zeeman energy. These results provide an example to show the subtle balance among complex competitions in materials with both strong correlation and spin-orbit coupling.
Federated domain generalization with global robust model aggregation strategy for bearing fault diagnosis
Authors: Cong Xiao , Song Yan , Li Yibin , Jia Lei
Published: July 2023

Federated learning ensures the privacy of fault diagnosis by maintaining a decentralized and local training data approach, eliminating the need to share confidential information with a central server. However, the performance of trained models tends to significantly deteriorate when applied to completely unseen domains. To address this challenge, this paper introduces a novel method called federated domain generalization with a global robust model aggregation strategy. Our proposed method can collaboratively train a model with outstanding generalization ability and robustness to unseen target domains in a data-protecting way. Specifically, a maximum mean discrepancy is introduced in the central server to reduce the discrepancy of features from different source clients. Meanwhile, classification loss across source domains is designed as the weights for local model aggregation in the central server. Finally, experimental results under two different bearing fault datasets show that our method obtains higher classification accuracy than other compared methods, which demonstrates that the proposed method has better generalization ability and is promising in real industrial applications.
A conveyor belt characterization information extraction method based on YOLOv5 and the skeleton method
Authors: Zeng Fei , Zhou Jian , Wu Qing
Published: July 2023

To resolve the inaccurate localization of conveyor belt surface damage identification problem and to address the insufficiencies of the methods for extracting surface characterization information, this paper proposes a conveyor belt characterization information extraction method that integrates YOLOv5 deep learning and the skeleton method. By constructing a conveyor belt surface damage recognition model based on the YOLOv5 target detection algorithm, the identification, localization and cropping of the conveyor belt’s surface damage are implemented. After that, edge extraction and surface information extraction are also performed on the damaged parts. Finally, the collected data are analyzed and processed in real time by edge computing equipment to determine the degree of damage of the parts. Finally, intelligent operation of the belt conveyor is achieved with autonomous operations, unattended operations and decision alarms. The experimental results show that the recognition accuracy of YOLOv5 is approximately 93.11%, the speed is approximately 57 frames per second and the error of the data acquired by image processing is between 2% and 10%, which meets the real-time detection requirements of conveyor belt surface damage detection, and assists in the safety management supervision of the belt conveyer.
Multivariant microstructure evolution in Ti-alloys: insights from a quantitative phase-field study
Authors: Bandyopadhyay Soumya , Panwar Vishal , Guin Sandip , C R Anoop , Gurao Nilesh Prakash , Mukherjee Rajdip
Published: July 2023

In the present work, we employ a CALPHAD-integrated physics-based quantitative multi-phase field model to study the microstructure evolution in a multi-phase Ti-alloy. In this model we use the free energies obtained from TTTI3 thermodynamic database for Ti-based alloys using a CALPHAD approach. For numerical implementation of the model, we solve the governing equations in their weak form using the open-source MOOSE finite element framework. Our model is successfully able to capture all the possible orientational variants in Ti- alloy system. Moreover, we elucidate the complex interaction between the variants using two- and multi-particle simulations. We show that the elastic energies associated with the variants play significant role in their growth behavior. We also explore the effect of anisotropy in interfacial energy on the variant evolution.
Thermal performance of dual flow slotted fin mini channel heat sink using Al2O3-H2O and TiO2-H2O: a numerical and experimental approach
Authors: Baig Taha , Adil Amna , Manzoor S , Ebrahem M , Tariq Hussain Ahmed , Ali Hafiz Muhammad
Published: July 2023

To overcome the extensive heat generation inside the microprocessors nanofluids have gained importance because of their better thermophysical properties as compared with air and water. This work proposes a two-pronged strategy for thermal performance enhancement of mini channel heat sinks. Firstly, a novel dual flow slotted fin mini channel heat sink flow configuration is proposed. Secondly, a detailed numerical investigation is performed to assess heat transfer enhancement property of Al2O3-H2O and TiO2-H2O nanofluids. Considering the first step, fin spacing, number of slots, slot thickness and slot angle are investigated in detail yielding to the selection of best structural parameters. Two slots per fin of 0.5 mm thickness at an angle of 45° is selected because it provides better thermal performance as compared with water. Further, numerical assessment of nano fluid behavior was carried out at volumetric concentrations of 0.005% and 0.01%. For the case of novel dual flow slotted fin mini channel heat sink, maximum numerical and experimental advantages in all targeted system properties is observed for Al2O3-H2O nano fluid at volumetric concentration of 0.01%, as compared with water. Al2O3-H2O nano fluid provides better thermal performance both numerically and experimentally as compared with TiO2-H2O nanofluids. Increment in the pressure drop is noted with increasing volumetric concentrations.
Identifying critical nodes in complex networks based on neighborhood information
Authors: Zhao Na , Wang Hao , Wen Jun-jie , Li Jie , Jing Ming , Wang Jian
Published: July 2023

The identification of important nodes in complex networks has always been a prominent topic in the field of network science. Nowadays, the emergence of large-scale networks has sparked our research interest in complex network centrality methods that balance accuracy and efficiency. Therefore, this paper proposes a novel centrality method called Spon (Sum of the Proportion of Neighbors) Centrality, which combines algorithmic efficiency and accuracy. Spon only requires information within the three-hop neighborhood of a node to assess its centrality, thereby exhibiting lower time complexity and suitability for large-scale networks. To evaluate the performance of Spon, we conducted connectivity tests on 16 empirical unweighted networks and compared the monotonicity and algorithmic efficiency of Spon with other methods. Experimental results demonstrate that Spon achieves both accuracy and algorithmic efficiency, outperforming eight other methods, including CycleRatio, collective influence, and Social Capital. Additionally, we present a method called W-Spon to extend Spon to weighted networks. Comparative experimental results on 10 empirical weighted networks illustrate that W-Spon also possesses advantages compared to methods such as I-Core and M-Core.