bluuebunny/crossref_metadata_2025 huggingface dataset:
Ballistic performance and overshoot effects in gallenene nanoribbon field-effect transistors
Authors: Poljak Mirko , Matić Mislav , Prevarić Ivan , Japec Karolina
Published: April 2024

Gallenene is a novel metallic 2D material that can provide a semiconducting counterpart if patterned into quasi-one-dimensional (quasi-1D) nanostructures, i.e., gallenene nanoribbons (GaNRs). We investigate semiconducting GaNRs as a potential channel material for future ultrascaled field-effect transistors (FETs) by employing quantum transport simulations based on Green's functions and tight-binding Hamiltonians with the orbital resolution calibrated on ab initio calculations. The impact of GaNR width downscaling from ∼6 nm down to ∼0.2 nm on the electronic, transport, and ballistic device properties is investigated for the FET channel length of 15 nm. We report current enhancement and injection velocity overshoot effects for sub-1.2 nm-wide nFETs and pFETs, with a maximum current increase of 53% in the 1.2 nm-wide GaNR pFET in comparison to the widest device. In addition, promising current-driving capabilities of n- and p-channel GaNR FETs are observed with top ballistic currents of more than 2.2 mA/μm and injection velocities of up to 2.4 × 107 cm/s. The reported data are explained by analyzing the evolution of band structure and related parameters such as injection velocity, quantum capacitance, effective transport mass etc., with increasing quantum confinement effects in ultranarrow GaNRs. Generally, we find that quasi-1D gallenene is a promising channel material for future nanoscale FETs, especially for transistor architectures based on stacked nanosheets.
Flow field reconstruction from spray imaging: A hybrid physics-based and machine learning approach based on two-phase fluorescence particle image velocimetry measurements
Authors: Zhao Fengnian , Zhou Ziming , Hung David , Li Xuesong , Xu Min
Published: April 2024

The interaction between liquid spray and the surrounding air is crucial in fluid research, especially in the study of fuel spray and combustion. However, the fuel spray–air interaction is a complex process influenced by multiple factors, including fuel type, fuel injection pressure, and fuel temperature. These factors are coupled together, making it challenging and time-consuming to accurately capture the spray–air data using traditional experimental methods alone. The current study proposes a hybrid physics-based and machine learning model for utilizing spray images to reconstruct ambient flow fields. The novelty of this work lies in leveraging the spatial characteristics of spray and airflow data to optimize feature extraction and reduce unnecessary nonlinearity in the model. Consequently, the model offers complementary advantages, improving model interpretability and reducing its reliance on massive data. The training dataset is collected using a combined diagnostic approach, utilizing Mie-scattering imaging and fluorescence particle image velocimetry. The liquid spray and the ambient air velocity field are measured simultaneously under a wide range of experimental conditions, including different fuel types, fuel injection pressures, and fuel temperatures. The reconstruction results are validated against unseen experimental data. In general, the reconstruction results indicate that the model is accurate, fast, and robust for different fuel conditions and injector types. It provides an innovative way to reconstruct airflow fields based on spray images (spray density distribution). These findings highlight the potential of integrating physics-based and machine learning methods for multiphase flow diagnostics, paving the way for broader data-driven applications in fluid research.
Using the Zeno line to assess and refine molecular models
Authors: Paterson Thomas , Bannerman Marcus N. , Lue Leo
Published: April 2024

The Zeno line is the locus of points on the temperature–density plane where the compressibility factor of the fluid is equal to one. It has been observed to be straight for a broad variety of real fluids, although the underlying reasons for this are still unclear. In this work, a detailed study of the Zeno line and its relation to the vapor–liquid coexistence curve is performed for two simple model pair-potential fluids: attractive square-well fluids with varying well-widths λ and Mie n-6 fluids with different repulsive exponents n. Interestingly, the Zeno lines of these fluids are curved, regardless of the value of λ or n. We find that for square-well fluids, λ ≈ 1.8 presents a Zeno line, which is the most linear over the largest temperature range. For Mie n-6 fluids, we find that the straightest Zeno line occurs for n between 8 and 10. Additionally, the square-well and Mie fluids with the straightest Zeno line showed the closest quantitative agreement with the vapor–liquid coexistence curve for experimental fluids that follow the principle of corresponding states (e.g., argon, xenon, krypton, methane, nitrogen, and oxygen). These results suggest that the Zeno line can provide a useful additional feature, in complement to other properties, such as the phase envelope, to evaluate molecular models.
Coupled finite-volume method and smoothed-particle hydrodynamics method for numerical simulation of interactions between inviscid shock waves and structures
Authors: Ning Jianguo , Zheng Kai , Xu Xiangzhao , Li Jianqiao
Published: April 2024

In this work, a novel coupled finite-volume method (FVM) and a smoothed-particle-hydrodynamics (SPH) method were developed for the simulation of interactions between inviscid shock waves and structures. In this approach, which considers the particles of a meshless method immersed in an FVM grid, the FVM grid cells are classified into either pure or mixed FVM cells, the latter of which contain SPH particles. A finite-element-method shape function is applied to map the variables from the SPH particles to the FVM cells, and the nodal and cell velocities are then obtained. The interaction of the fluid with the structure is computed using moving reflection boundary conditions at cell interfaces with SPH particles. The interactions of the structure with the fluid are computed from the pressure differences around the SPH particles. The processes for computing the coupled FVM–SPH method are described in detail herein. The validity of the presented coupled FVM–SPH method was verified using a theoretical model of a piston, and the numerical results were found to agree well with the theoretical approximations, indicating the accuracy of the proposed coupled method. The results of the method were then compared with the results of an experiment involving a blast-driven steel plate. Good agreement between the experimental and numerical results was obtained, and the maximum difference was 3.44%, demonstrating the effectiveness of the proposed coupled FVM–SPH method when applied to the interaction of a shock wave with a structure.
Insight into porous fin microchannel heat sinks with improved thermo-hydraulic performance
Authors: Abdollahzadehsangroudi M. , Francisco M. , Lopes R. , Dolati F. , Pascoa J. C. , Rodrigues F.
Published: April 2024

The escalating demand for enhanced cooling systems, particularly in high-power computer processors, necessitates innovative solutions within the spatial constraints of computing environments. This paper introduces a design modification that strategically diverts a portion of the main flow toward and through the porous fin region, creating a “cross flow.” The novel approach aims to maximize heat transfer through the fins, harnessing both conduction and convection heat transfer mechanisms. The realization of these flow patterns is achieved through interdigitated blocking of the inlet and outlet reigns of the microchannel, coupled with the utilization of converging and diverging microchannel porous fins in distinct elbow and zigzag geometrical configurations. Numerical simulations using computational fluid dynamics are employed to assess the proposed microchannel heat sink's thermo-hydraulic performance. The proposed design innovation significantly enhances heat dissipation efficiency by augmenting the convection heat transfer mechanism within the porous fins, resulting in a remarkable 17% improvement in Nusselt number compared to conventional parallel microchannel heat sinks with porous fins. This study provides valuable insight into the thermal and hydraulic performance of the proposed design, offering promising prospects for addressing the escalating demand for enhanced cooling systems in high-power computing environments.
Effects of nonlinearities on the gap resonances between two free-heaving barges
Authors: Jing Penglin , He Guanghua , Zhang Cheng , He Runhua , Zhang Zhigang
Published: April 2024

The hydrodynamic characteristics of the gap resonances between two identical side-by-side barges are investigated in a constrained interpolation profile method-based numerical wave tank. Each barge can heave freely under the excitation of the incident waves. This paper mainly concentrates on the influences of the nonlinearities during the gap resonances on their hydrodynamic performance, via the parameter study of the incident-wave height. Numerical results demonstrated that the nonlinear gap resonances' magnitudes may reach close to or exceed that of the linear gap resonance and naturally contain strong nonlinearities when considering the heave responses of the side-by-side barges. Meanwhile, the effects of the heave responses on the key hydrodynamic parameters cannot be ignored as well. Therefore, the wave run-ups of the barges are of significant importance for the investigation. On the one hand, the wave run-ups directly reflect the coupling effects between the gap resonances and the twin barges' heave responses. On the other hand, the nonlinearities of the wave run-ups perform stronger than the wave elevation at the gap. Moreover, the linear wave run-ups are proposed via the linear formulas to qualitatively and quantitively investigate the effects of the nonlinearities on the inner process of the wave run-ups by comparison. Based on the harmonic analysis, the features of the distributions of the first four order harmonics of the wave elevation at the gap, the wave run-ups, and the wave loads are illustrated.
Improving gas adsorption modeling for MOFs by local calibration of Hubbard U parameters
Authors: Cho Yeongsu , Kulik Heather J.
Published: April 2024

While computational screening with density functional theory (DFT) is frequently employed for the screening of metal–organic frameworks (MOFs) for gas separation and storage, commonly applied generalized gradient approximations (GGAs) exhibit self-interaction errors, which hinder the predictions of adsorption energies. We investigate the Hubbard U parameter to augment DFT calculations for full periodic MOFs, targeting a more precise modeling of gas molecule–MOF interactions, specifically for N2, CO2, and O2. We introduce a calibration scheme for the U parameter, which is tailored for each MOF, by leveraging higher-level calculations on the secondary building unit (SBU) of the MOF. When applied to the full periodic MOF, the U parameter calibrated against hybrid HSE06 calculations of SBUs successfully reproduces hybrid-quality calculations of the adsorption energy of the periodic MOF. The mean absolute deviation of adsorption energies reduces from 0.13 eV for a standard GGA treatment to 0.06 eV with the calibrated U, demonstrating the utility of the calibration procedure when applied to the full MOF structure. Furthermore, attempting to use coupled cluster singles and doubles with perturbative triples calculations of isolated SBUs for this calibration procedure shows varying degrees of success in predicting the experimental heat of adsorption. It improves accuracy for N2 adsorption for cases of overbinding, whereas its impact on CO2 is minimal, and ambiguities in spin state assignment hinder consistent improvements of O2 adsorption. Our findings emphasize the limitations of cluster models and advocate the use of full periodic MOF systems with a calibrated U parameter, providing a more comprehensive understanding of gas adsorption in MOFs.
Energy transfer in compressible channel flows with two-dimensional sinusoidal rough walls
Authors: Chen Sanmu , Zhang Wen , Han Jiahui , Wan Minping
Published: April 2024

We perform direct numerical simulations to investigate the effect of two-dimensional sinusoidal roughness in the compressible channel flows with varying roughness height at Mach numbers M0=0.8 and 1.5. We observed the strong oblique shock waves and alternating compression/expansion regions are generated due to the roughness at higher Mach number, which also results in higher temperature in the channel center. The effects of roughness height on the transfer between the kinetic and internal energies are analyzed in detail. We found that the roughness significantly enhances the production of the turbulent kinetic energy while the Mach number has little influence on this term. The transfer terms between kinetic and internal energies are pressure- and viscosity-related, and is dominated by the viscous terms. The roughness-induced shock waves strongly affect the local distributions of the pressure-related terms, but its spatial average is only slightly modified. The energy transfer from the mean kinetic energy to both the internal energy and the turbulent kinetic energy is amplified by the roughness through the viscous terms. The average effect of roughness is intensified as the roughness height increases, but is insensitive to the Mach number variation.
Chemotactic particles as strong electrolytes: Debye–Hückel approximation and effective mobility law
Authors: Illien Pierre , Golestanian Ramin
Published: April 2024

We consider a binary mixture of chemically active particles that produce or consume solute molecules and that interact with each other through the long-range concentration fields they generate. We analytically calculate the effective phoretic mobility of these particles when the mixture is submitted to a constant, external concentration gradient, at leading order in the overall concentration. Relying on an analogy with the modeling of strong electrolytes, we show that the effective phoretic mobility decays with the square root of the concentration: our result is, therefore, a nonequilibrium counterpart to the celebrated Kohlrausch and Debye–Hückel–Onsager conductivity laws for electrolytes, which are extended here to particles with long-range nonreciprocal interactions. The effective mobility law we derive reveals the existence of a regime of maximal mobility and could find applications in the description of nanoscale transport phenomena in living cells.
Static versus dynamically polarizable environments within the many-body GW formalism
Authors: Amblard David , Blase Xavier , Duchemin Ivan
Published: April 2024

Continuum- or discrete-polarizable models for the study of optoelectronic processes in embedded subsystems rely mostly on the restriction of the surrounding electronic dielectric response to its low frequency limit. Such a description hinges on the assumption that the electrons in the surrounding medium react instantaneously to any excitation in the central subsystem, thus treating the environment in the adiabatic limit. Exploiting a recently developed embedded GW formalism with an environment described at the fully ab initio level, we assess the merits of the adiabatic limit with respect to an environment where the full dynamics of the dielectric response are considered. Furthermore, we show how to properly take the static limit of the environment’s susceptibility by introducing the so-called Coulomb-hole and screened-exchange contributions to the reaction field. As a first application, we consider a C60 molecule at the surface of a C60 crystal, namely, a case where the dynamics of the embedded and embedding subsystems are similar. The common adiabatic assumption, when properly treated, generates errors below 10% on the polarization energy associated with frontier energy levels and associated energy gaps. Finally, we consider a water molecule inside a metallic nanotube, the worst case for the environment’s adiabatic limit. The error on the gap polarization energy remains below 10%, even though the error on the frontier orbital polarization energies can reach a few tenths of an electronvolt.
Accurate low-energy pulse system for intravascular lithotripsy
Authors: Ren Jiacheng , Shen Qihui , Shao Jingzhen , Lin Ying , Liang Xu
Published: April 2024

In response to biomedical imperatives, a novel approach is presented for the endovascular management of atherosclerosis. This approach is grounded in the electrohydraulic effect of a precisely controlled low-energy pulse discharge system, coupled with sequential control within the incomplete discharge electrode, to generate shockwaves aimed at softening blood vessels and rupturing calcified plaques. Theoretical analysis encompassed circuit design, control timing, and operational processes, while experimental investigations demonstrated precise control of non-oscillation and incomplete discharge by adjusting key parameters. Utilizing a 3 kV DC high-voltage power supply, a 220 nF capacitor, and two sets of 3.3 Ω resistors in parallel, with pin–plate electrodes as the load for discharge in normal saline, resulted in a 1 kV reduction in voltage across the capacitor and a peak current of 170 A. Energy release occurred through non-oscillatory and incomplete discharge, effectively generating shockwaves with peak pressures of 5–10 MPa at distances of 1–2 mm from the discharge center to treat calcified lesions. Compared with the existing intravascular lithotripsy devices, the shockwave system realizes accurate control of discharge energy by adjusting the turn-off time of incomplete discharge so as to realize accurate control of shockwave energy. Doctors can choose different intensities of shockwaves according to different degrees of calcification in the treatment process so as to minimize the discomfort caused by shockwaves and improve safety. Valuable insights are provided for intravascular lithotripsy devices in engineering.
Vicariance and cryptic diversity revealed by molecular phylogenetic analyses of estuarine Gammarus species (Crustacea: Amphipoda) due to formation of the Labrador Current
Authors: Smith Liyah , Long Richard A. , Cannizzaro Andrew G. , Sawicki Thomas R.
Published: April 2024

The metapopulation of the estuarine species Gammarus tigrinus along the east coast of the United States has been hypothesised to represent two cryptic species divided biogeographically off the coast of North Carolina, USA. This divergence has been attributed to a strong temperature gradient created by the formation of the cold Labrador Current c. 3.0 million years ago. In addition, the northern phylogeographic clade of G. tigrinus has been demonstrated to be invasive in estuarine habitats across a large portion of northern Europe. Recent collections of G. tigrinus from Florida and Maryland, USA, allow for new approaches to test this hypothesis. Using the nuclear 18S and 28S rRNA, and mitochondrial 16S rRNA and cytochrome c oxidase subunit I genes, species delimitation models provide support that the genetic divergence of the northern and southern clades is equivalent to species level. In addition, molecular clock data demonstrate that this phylogeographic divergence coincides with the formation of the Labrador Current. Furthermore, the collections of G. daiberi from Florida, a species with biogeographical and ecological characteristics similar to those of G. tigrinus, provide independent support for the hypothesis. The potential for invasive species to be cryptic highlights the need for accurate identification of taxa to ensure that appropriate biogeographical assessment of potential source populations and mechanisms of dispersal can be made.
Trialling a new method to attract feral cats (Felis catus) in situ – the Mata Hari Judas queen
Authors: Dennien Abby L. , Edwards Megan C. , Hoy Julia M. , Nicolson Vere , Brady Megan J. , Murray Peter J.
Published: April 2024

Context Feral cats are a significant threat to wildlife in Australia and globally. Current feral cat management techniques have limitations that can result in wary, remnant individuals persisting in the landscape and reducing overall pest control efficacy, thus there is a need for additional innovative management techniques. Aims This research aimed to identify whether the Mata Hari Judas technique could be applied to female cats (queens) in situ as a means of attracting and assisting the capture of feral cats. Methods Three queens were induced into prolonged oestrus and contained in enclosures (vennels) in situ with traps attached to capture attracted feral cats. Two vennel treatments were trialled, one housing a Mata Hari Judas queen (queen vennel) and another using auditory and olfactory lures from a Mata Hari Judas queen (faux queen vennel) to compare the attractiveness of the two treatments at three study sites. Camera traps and soil plots were used to monitor and compare cat activity surrounding the vennels prior to, during and after the presence of a Mata Hari Judas queen or her lures. Key results Both vennel treatments attracted multiple feral cats of both sexes, and each trapped one male cat, demonstrating proof of concept for this technique. The queen vennel was significantly more attractive than the faux queen vennel, as demonstrated by higher frequency of cat detections and the duration of time feral cats spent at this vennel. Comparisons between monitoring periods and when the vennels were active showed significant differences in the frequency of cats attracted to the area, further supporting that both the queen and her lures were attractive to cats. Conclusions This research is the first instance where Mata Hari Judas queens have been successfully used in situ to attract and capture feral cats. Future studies should aim to assess this technique in a controlled area with a known cat population to allow for a direct comparison of efficacy with more traditional feral cat management methods. Implications With further refinement, the use of Mata Hari Judas queens in situ could provide an efficient technique for removing remnant cats.
APOBEC2 safeguards skeletal muscle cell fate through binding chromatin and regulating transcription of non-muscle genes during myoblast differentiation
Authors: Lorenzo J. Paulo , Molla Linda , Amro Elias Moris , Ibarra Ignacio L. , Ruf Sandra , Neber Cedrik , Gkougkousis Christos , Ridani Jana , Subramani Poorani Ganesh , Boulais Jonathan , Harjanto Dewi , Vonica Alin , Di Noia Javier M. , Dieterich Christoph , Zaugg Judith B. , Papavasiliou F. Nina
Published: April 2024

The apolipoprotein B messenger RNA editing enzyme, catalytic polypeptide (APOBEC) family is composed of nucleic acid editors with roles ranging from antibody diversification to RNA editing. APOBEC2, a member of this family with an evolutionarily conserved nucleic acid–binding cytidine deaminase domain, has neither an established substrate nor function. Using a cellular model of muscle differentiation where APOBEC2 is inducibly expressed, we confirmed that APOBEC2 does not have the attributed molecular functions of the APOBEC family, such as RNA editing, DNA demethylation, and DNA mutation. Instead, we found that during muscle differentiation APOBEC2 occupied a specific motif within promoter regions; its removal from those regions resulted in transcriptional changes. Mechanistically, these changes reflect the direct interaction of APOBEC2 with histone deacetylase (HDAC) transcriptional corepressor complexes. We also found that APOBEC2 could bind DNA directly, in a sequence-specific fashion, suggesting that it functions as a recruiter of HDAC to specific genes whose promoters it occupies. These genes are normally suppressed during muscle cell differentiation, and their suppression may contribute to the safeguarding of muscle cell fate. Altogether, our results reveal a unique role for APOBEC2 within the APOBEC family.
A frictional soliton controls the resistance law of shear-thickening suspensions in pipes
Authors: Bougouin Alexis , Metzger Bloen , Forterre Yoël , Boustingorry Pascal , Lhuissier Henri
Published: April 2024

Pipe flows are commonly found in nature and industry as an effective mean of transporting fluids. They are primarily characterized by their resistance law, which relates the mean flow rate to the driving pressure gradient. Since Poiseuille and Hagen, various flow regimes and fluid rheologies have been investigated, but the behavior of shear-thickening suspensions, which jam above a critical shear stress, remains poorly understood despite important applications (e.g., concrete or food processing). In this study, we build on recent advances in the physics of shear-thickening suspensions to address their flow through pipes and establish their resistance law. We find that for discontinuously shear-thickening suspensions (large particule volume fractions), the flow rate saturates at high driving stress. Local pressure and velocity measurements reveal that this saturation stems from the emergence of a frictional soliton: a unique, localized, superdissipative, and backpropagating flow structure coexisting with the laminar frictionless flow phase observed at low driving stress. We characterize the remarkably steep effective rheology of the frictional soliton and show that it sets the resistance law at the whole pipe scale. These findings offer an unusual perspective on low-Reynolds suspension flows through pipes, intriguingly reminiscent of the transition to turbulence for simple fluids. They also provide a predictive law for the transport of such suspensions in pipe systems, with implications for a wide range of applications.
Carboxyl-terminal sequences in APOA5 are important for suppressing ANGPTL3/8 activity
Authors: Chen Yan Q. , Yang Ye , Zhen Eugene Y. , Beyer Thomas P. , Li Hongxia , Wen Yi , Ehsani Mariam , Jackson Nicholas , Xie Katherine , Jung Hyesoo , Scheithauer Julia L. , Kumari Anni , Birrane Gabriel , Russell Anna M. , Balasubramaniam Deepa , Liao Zhongping , Siegel Robert W. , Qian Yuewei , Ploug Michael , Young Stephen G. , Konrad Robert J.
Published: April 2024

Apolipoprotein AV (APOA5) lowers plasma triglyceride (TG) levels by binding to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppressing its capacity to inhibit lipoprotein lipase (LPL) catalytic activity and its ability to detach LPL from binding sites within capillaries. However, the sequences in APOA5 that are required for suppressing ANGPTL3/8 activity have never been defined. A clue to the identity of those sequences was the presence of severe hypertriglyceridemia in two patients harboring an
APOA5
mutation that truncates APOA5 by 35 residues (“APOA5Δ35”). We found that wild-type (WT) human APOA5, but not APOA5Δ35, suppressed ANGPTL3/8’s ability to inhibit LPL catalytic activity. To pursue that finding, we prepared a mutant mouse APOA5 protein lacking 40 C-terminal amino acids (“APOA5Δ40”). Mouse WT-APOA5, but not APOA5Δ40, suppressed ANGPTL3/8’s capacity to inhibit LPL catalytic activity and sharply reduced plasma TG levels in mice. WT-APOA5, but not APOA5Δ40, increased intracapillary LPL levels and reduced plasma TG levels in
Apoa5
−/−
mice (where TG levels are high and intravascular LPL levels are low). Also, WT-APOA5, but not APOA5Δ40, blocked the ability of ANGPTL3/8 to detach LPL from cultured cells. Finally, an antibody against a synthetic peptide corresponding to the last 26 amino acids of mouse APOA5 reduced intracapillary LPL levels and increased plasma TG levels in WT mice. We conclude that C-terminal sequences in APOA5 are crucial for suppressing ANGPTL3/8 activity in vitro and for regulating intracapillary LPL levels and plasma TG levels in vivo.
The serine phosphorylations in the IRS-1 PIR domain abrogate IRS-1 and IR interaction
Authors: Woo Ju Rang , Bae Seung-Hyun , Wales Thomas E. , Engen John R. , Lee Jongsoon , Jang Hyonchol , Park SangYoun
Published: April 2024

Serine phosphorylations on insulin receptor substrate 1 (IRS-1) by diverse kinases aoccur widely during obesity-, stress-, and inflammation-induced conditions in models of insulin resistance and type 2 diabetes. In this study, we define a region within the human IRS-1, which is directly C-terminal to the PTB domain encompassing numerous serine phosphorylation sites including Ser307 (mouse Ser302) and Ser312 (mouse 307) creating a phosphorylation insulin resistance (PIR) domain. We demonstrate that the IRS-1 PTB-PIR with its unphosphorylated serine residues interacts with the insulin receptor (IR) but loses the IR-binding when they are phosphorylated. Surface plasmon resonance studies further confirm that the PTB-PIR binds stronger to IR than just the PTB domain, and that phosphorylations at Ser307, Ser312, Ser315, and Ser323 within the PIR domain result in abrogating the binding. Insulin-responsive cells containing the mutant IRS-1 with all these four serines changed into glutamates to mimic phosphorylations show decreased levels of phosphorylations in IR, IRS-1, and AKT compared to the wild-type IRS-1. Hydrogen–deuterium exchange mass spectrometry experiments indicating the PIR domain interacting with the N-terminal lobe and the hinge regions of the IR kinase domain further suggest the possibility that the IRS-1 PIR domain protects the IR from the PTP1B-mediated dephosphorylation.
Surface acoustic wave induced transport and strain phenomena in van der Waals materials
Authors: Zhao P , Sharma C H , Tiemann L , Blick R H
Published: April 2024

Surface acoustic waves, the microcosmic cousins of seismic waves, can be generated and precisely controlled on a microscopic scale by applying a periodic electrical signal to a piezoelectric substrate. Harnessing and exploring their interactions with two-dimensional van der Waals (vdW) systems opens new frontiers in materials science and engineering. As part of a special issue on these guided elastic waves for hybrid nano- and quantum technologies, our review highlights work focusing on acoustically-induced transport phenomena at low temperatures that arise from the interaction between the surface acoustic waves in a piezoelectric substrate and a vdW material on its surface. A main focus is on technological methods to control the carrier concentration in transport and strain-related effects that can act on the carrier motion as an effective magnetic field.
Binary and ternary ferromagnetic alloy/C nanocapsules for improved X-band microwave absorption
Authors: Hassan Sibt Ul , Yang Yang , Kuang Daitao , Qamar Tauqeer Haider , Zai MinMing , Zafar Sana , Hou Lizhen , Wang Shiliang
Published: April 2024

The dielectric-magnetic matching effect emerges from the presence of dual dielectric relaxation and multiple magnetic resonances. This phenomenon becomes a strategic approach in the quest to enhance microwave absorption performance by optimizing magnetic components. Herein, binary and ternary ferromagnetic alloy with tunable components embedded in carbon skeleton (core/shell) nanocapsules has been successfully fabricated by one step metal-organic chemical vapor deposition. The core/shell structure design introduces numerous interfaces that amplify dielectric loss stemming from polarization. It is important to emphasize that modifying the composition of magnetic core in these nanocapsules effectively regulates the impedance matching characteristics. As a result, the CoFeNi/C nanocapsules demonstrate an optimal reflection loss (RLmin) of −53.6 dB at a thickness of 2.55 mm, alongside an effective absorption bandwidth of 5.92 GHz at a thickness of 2.05 mm, with a filling ratio as low as 20 wt%. This study has provided valuable insights into a promising avenue for fabricating dielectric-magnetic nanocomposites with outstanding microwave attenuation capabilities through the manipulation of composited elements.
The oblique parameters in the 2HDM with vector-like quarks: confronting M

W
CDF-II anomaly
Authors: Abouabid H , Arhrib A , Benbrik R , Boukidi M , El Falaki J
Published: April 2024

The CDF collaboration has released a new measurement of the W boson mass using their complete data set with 8.8 fb−1 in

p

p

¯

collisions. This result deviates from the Standard Model prediction by around 7σ. We explain how the two Higgs doublet model (2HDM) with vector-like quarks (VLQs) is affected by the recently discovered W boson mass. In our study, we include both theoretical constraints such as perturbative unitarity and vacuum stability as well as a number of experimental constraints. We also look into how the effective mixing angle, measured by the SLD collaboration in addition to the CDF W-boson mass, is used to determine the S and T parameters. In the alignment limit, we investigate the case where the lighter CP-even neutral Higgs boson of the 2HDM is the one found at the LHC and demonstrate how the parameter space of the 2HDM type II in the presence of VLQs is constrained. It is found that in most cases, there is a cancellation between the 2HDM and VLQs contributions, which enlarges the parameter space of both models.
Meshless track assimilation (MTA) of 3D PTV data
Authors: Sperotto Pietro , Watz Bo , Hess David
Published: April 2024

We propose a data assimilation algorithm to improve the resolution of 3D particle tracking velocimetry (PTV) data and, as a byproduct, it estimates the pressure field. The proposed method, called meshless tracking assimilation (MTA), does not rely on a mesh to compute derivatives. Instead, it exploits the analytical formulation of the obtained field to extract the gradients of the involved quantities in arbitrary points. MTA actively constraints PTV data points to satisfy the Navier–Stokes equations in both time and space at user-defined spatial locations. Three test cases are investigated. The first one is a synthetic dataset reconstructed from a direct numerical simulation and it serves to ensure that the method is properly implemented and working. The second one is the 2020 data assimilation challenge which gives a qualitative comparison with other data assimilation methods. Finally, MTA is used on a Tomographic PTV experiment of a Jet Flow with

R

e
D

≃
3000

to ensure it can be implemented successfully on experimental data. The first and third test cases show a significant performance boost compared to the classic linear interpolation. This improvement allows for a higher level of structural resolution without sacrificing the temporal and spatial smoothness of the solution. The second test case generally aligns well with other state-of-the-art data assimilation techniques in terms of performance, but there are some noticeable differences.
Dual-path multi-scale attention residual network for fault diagnosis of rolling bearings under complex operating conditions
Authors: Deng Linfeng , Zhang Yuanwen , Zhao Cheng , Wang Guojun
Published: April 2024

Rolling bearing faults inevitably occur during the long-term continuous operation of rotating machinery. Therefore, fault diagnosis is greatly important for ensuring the normal and safe operation of rolling bearings. However, the complexity and diversity of working conditions of rolling bearings present a significant challenge in extracting fault characteristics accurately, which further affects the ultimate fault diagnosis results. In this article, we propose a new model, called dual-path multi-scale attention residual network (DPMARN), for diagnosing bearing faults under complex operating conditions. DPMARN can effectively capture the feature-feature correlation information at different scales, which is more beneficial for fusing fault features at different scales to improve the model’s performance. The main contributions of this work are summarized as follows: (1) the designed dual-path network model which incorporates parallel multi-scale branches of convolutional kernels and serially connects skip-layer multi-scale branches can integrate both low-frequency and high-frequency information and enhance the multi-scale feature extraction and complex data representation abilities. (2) The squeeze-and-excitation attention mechanism is embedded into the residual blocks to improve the ability of learning feature correlations and utilizing feature information effectively, which is helpful for extracting important fault characteristics. Extensive experiments conducted on two public bearing datasets demonstrate the superior performance of the DPMARN model for addressing the complex fault diagnosis problem. These results indicate that our proposed approach provides an effective solution for fault diagnosis of rolling bearings under complex operating conditions.
Ionization layer with collision-free atoms at the edge of partially to fully ionized plasmas
Authors: Benilov M S
Published: April 2024

When a hot arc spot has just formed on the cathode surface, e.g. in the course of arc ignition on a cold cathode, a significant part of the current still flows in the glow-discharge mode to the cold surface outside the spot. The near-cathode voltage continues to be high at all points of the cathode surface. The mean free path for collisions between the atoms and the ions within the plasma ball near the spot is comparable to, or exceeds, the thickness of the ionization layer, which is a part of the near-cathode non-equilibrium layer where the ion current to the cathode is generated. The evaluation of the ion current to the cathode surface under such conditions is revisited. A fluid description of the ion motion in the ionization layer is combined with a kinetic description of the atom motion. The resulting problem admits a simple analytical solution. Formulas for the evaluation of the ion current to the cathode for a wide range of conditions are derived and the possibilities of using these formulas to improve the accuracy of existing methods for modeling high-pressure arc discharges in relation to glow-to-arc transitions are discussed.
Laser ablation of thin SiN
x
layer coated on silicon wafer—evaluation of process performance for PERC solar cell application
Authors: Rana Pinal , Prasad Khatri Durga , Kottantharayil Anil , Marla Deepak
Published: April 2024

In fabricating passivated emitter and rear contact (PERC) solar cells, creating small openings on the SiN

x

coated silicon substrate to establish metal contacts necessitates using a nanosecond pulsed green laser for ablation. However, the thermal nature of laser ablation poses a challenge. Excessive nitrogen diffusion from SiN

x

into the silicon substrate can compromise the electrical performance of solar cells. Therefore, this study aims to comprehensively understand how laser parameters impact the electrical properties of such solar cells. PERC solar cell precursors were initially fabricated by ablating the SiN

x

layer at four laser fluences, each corresponding to different regimes: solid, liquid, vapor, and phase explosion. Subsequently, various optical, chemical, and electrical characterizations were conducted on the solar cell precursors. Complete PERC solar cells were also fabricated to measure quantum efficiency (QE). In the solid regime, SiN

x

removal is precise, with minimal thermal damage, resulting in a nitrogen concentration of approximately 0.15%. Photoluminescence count and carrier lifetime are notably higher by 21% in the solid regime compared to the explosive regime. The QE measurement at 984 nm quantitatively assesses rear-side recombination losses. Notably, 26% of the area exhibits a 56% QE in the solid state, while this number drops to around 22% in the explosive state. This decline can be attributed to increased thermal damage in the explosive regime, which augments recombination centers and diminishes the solar cell performance. PERC solar cells ablated in the solid regime showcase lower subsurface damage, superior electrical characteristics, and higher performance than those ablated in the explosive regime.
Vortex-glass transition and vortex pinning behavior in three-dimensional NbTiN epitaxial films
Authors: Han Zi-Yan , Jing Tian-Yu , Yang Jian , Cai Wen-Bo , Li Zhi-Qing
Published: April 2024

In the present paper, the vortex dynamics in two NbTiN epitaxial films have been explored via analyzing the current–voltage (I–V) curves measured at different temperatures and fields. The thicknesses of the two films are ∼50 and ∼100 nm, respectively, and they are three-dimensional (3D) with respect to superconductivity. The films transform from normal state to superconducting state with decreasing temperature at zero field, and the values of superconducting transition temperature

T
c

are 8.73 and 12.03 K for the ∼50- and ∼100-nm-thick films, respectively. When a magnetic field with magnitude

0.5

T
≲

μ
0

H
≲
7

 T and perpendicular to the film plane is applied, the isothermal I–V data show a 3D vortex-glass (VG) scaling collapse at each field, suggesting that a 3D vortex-liquid phase to VG phase transition occurs in the NbTiN films. By analyzing the critical current density, we found that core pinning is the main pinning mechanism in the films. In addition, it is found that the normal point-like pinning dominates the pinning behavior at low field regime. While in the high field regime, besides the normal point-like pinning, other pinning mechanisms, such as Δκ pinning, also exist in the films. Our results not only provide strong experimental support for the occurrence of VG phase transition in conventional superconductors, but also provide fundamental information for the application of NbTiN films.
Steady-state entanglement production in a quantum thermal machine with continuous feedback control
Authors: Francesco Diotallevi Giovanni , Annby-Andersson Björn , Samuelsson Peter , Tavakoli Armin , Bakhshinezhad Pharnam
Published: April 2024

Quantum thermal machines can generate steady-state entanglement by harvesting spontaneous interactions with local environments. However, using minimal resources and control, the entanglement is typically weak. Here, we study entanglement generation in a two-qubit quantum thermal machine in the presence of a continuous feedback protocol. Each qubit is measured continuously and the outcomes are used for real-time feedback to control the local system-environment interactions. We show that there exists an ideal operation regime where the quality of entanglement is significantly improved, to the extent that it can violate standard Bell inequalities and uphold quantum teleportation. In agreement with (Khandelwal et al 2020 New J. Phys.
22 073039), we also find, for ideal operation, that the heat current across the system is proportional to the entanglement concurrence. Finally, we investigate the robustness of entanglement production when the machine operates away from the ideal conditions.
Uncertainty relation and the constrained quadratic programming
Authors: Zhang Lin , Wu Dade , Zhao Ming-Jing , Nan Hua
Published: April 2024

The uncertainty relation is a fundamental concept in quantum theory, plays a pivotal role in various quantum information processing tasks. In this study, we explore the additive uncertainty relation pertaining to two or more observables, in terms of their variance, by utilizing the generalized Gell-Mann representation in qudit systems. We find that the tight state-independent lower bound of the variance sum can be characterized as a quadratic programming problem with nonlinear constraints in optimization theory. As illustrative examples, we derive analytical solutions for these quadratic programming problems in lower-dimensional systems, which align with the state-independent lower bounds. Additionally, we introduce a numerical algorithm tailored for solving these quadratic programming instances, highlighting its efficiency and accuracy. The advantage of our approach lies in its potential ability to simultaneously achieve the optimal value of the quadratic programming problem with nonlinear constraints but also precisely identify the extremal state where this optimal value is attained. This enables us to establish a tight state-independent lower bound for the sum of variances, and further identify the extremal state at which this lower bound is realized.
Recent advancements in supercapacitors and their charge storage mechanism and progress in transition metal sulfide-based electrodes
Authors: Khan Mohd Shakir , Shariq Mohammad , Bouzgarrou Souhail Mohammed , Azooz Rehab E , Ali Syed kashif , Ghaly Waleed A , Hassan K F
Published: April 2024

Efficient energy storage strategies have become a major priority in the last few years. Transition metal sulphides are popularly known as attractive electrode materials or supercapacitors due to their high theoretical capacitance, excellent electrical conductivity, and favourable redox properties. Through compositional and structural engineering, some transition metal sulphides like Mn, V, Co, Fe, Cu, Ni, Mo, Zn, W, and Sn have shown substantial improvements in electrochemical performance. Composite engineering and morphological control are two of the key strategies employed to improve the TMS electrode’s electrochemical performance. Excellent electrochemical TMSs address the issues of slow kinetics, poor stability, and large volume expansions. This study reveal optimised TMSs potential to transform supercapacitor applications and provides viable approaches to conquer current hurdles to shape the forthcoming century’s high-performance and low-cost energy storage technology. The effects of composite engineering and morphological control on the ultimate electrochemical performance of the electrode materials are the primary focus of this investigation. Challenges to the further advancement of transition metal sulphide-based electrode materials are also explored in this article. Critical approaches to resolving significant issues in our current understanding of the kinetic and mechanistic perspectives of charge storage processes, i.e., slow kinetics, poor stability, and volume expansions, are also highlighted. Ultimately, future potentials, challenges, and possible solutions to tackle these problems are broadly discussed.
Optical properties of the O3+-ion implanted and femtosecond-laser ablated ridge waveguide in the Er3+-doped germanate glass
Authors: Zhao Jie , Ni Xiao , Huo Yuan-Yang , Sun Wang , Zhang Liao-Lin , Liu Chun-Xiao
Published: April 2024

Er3+-doped germanate glass is a kind of polyfunctional material for optical and photonic applications. The work reports on the preparation and properties of O3+-ion implanted and femtosecond-laser ablated Er3+-doped germanate glass optical ridge waveguide. The energy is 6.0 MeV and the fluence is 5 × 1014 ions cm−2 for the O3+-ion implantation. The pulse energy and the scanning speed of the femtosecond-laser ablation are 3 μJ and 50 μm s−1, respectively. The SRIM 2013 is used to calculate the vacancy profile induced by the implantation in the Er3+-doped germanate glass for the physical mechanisms of the waveguide formation. The optical microscopy images of the cross-section of the waveguide are captured by the Nikon microscope. The light-guiding properties of the ion-implanted and laser-ablated waveguides are studied by the end-face coupling system. The ridge waveguide has been produced by combining the FS ablation with ion implantation technologies for the first time in the Er3+-doped germanate glass. The propagation of light field indicates that it has the potential for photonics applications based on the planar and ridge Er3+-doped germanate glass waveguides.