bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast switching Ga2O3 Schottky barrier power diode with beveled-mesa and BaTiO3 field plate edge termination
Authors: Sun N. , Gong H. H. , Hu T. C. , Zhou F. , Wang Z. P. , Yu X. X. , Ren F.-F , Gu S. L. , Lu H. , Zhang R. , Ye J. D.
Published: October 2024

Power devices rely on ideal edge termination to suppress the electric field crowding and avoid premature breakdown before the material's critical field is reached. In this work, a hybrid electric field management configuration, featuring the combination of beveled-mesa (BM) termination and high-k oxide BaTiO3 field plate (FP), was implemented in Ga2O3 Schottky barrier diodes (SBDs). This BMFP-SBD realizes a breakdown voltage (BV) of 1.7 kV with extremely low reverse leakage current, outperforming the BM terminated SBD with BV of 0.64 kV and bare SBD with BV of 0.22 kV. Based on the temperature-dependent reverse characteristics, the dominant leakage mechanism transforms from Poole–Frenkel (P–F) emission in BM-SBD to variable-range-hopping (VRH) in BMFP-SBD at high bias. In particular, under switching conditions of di/dt up to 420 A/μs, the BMFP-SBD exhibits superior dynamic switching characteristics with a short reverse recovery time of 10.1 ns, which are comparable with those in advanced commercial SiC SBDs. These findings underscore the potential of Ga2O3 SBD enabled by BM and high-k FP edge termination for high-speed and high-voltage power electronics applications.
Challenges and opportunities in high efficiency scalable and stable perovskite solar cells
Authors: Hossain Kashimul , Nayak Suryanarayan , Kabra Dinesh
Published: October 2024

Perovskite solar cells (PSCs) are the fastest-growing photovoltaic (PV) technology and hold great promise for the photovoltaic industry due to their low-cost fabrication and excellent efficiency. To achieve commercial readiness level, the most important factor would be yield beyond 95% at the PSC module levels. The current essential requirements for PSCs are reproducibility of high efficiency devices, scalability, and stability. The reported certified high efficiency (24–26%) results are based on the use of FAPbI3 perovskites with a bandgap of Eg≈ 1.5 eV, and the typical device's active area ranges from ≈ 0.1 cm2 to a maximum of 1 cm2. However, relatively higher bandgap PSCs are essential, especially in tandem solar cell applications. Hence, optimization of higher bandgap PSCs is a necessity. As the bandgap of the perovskites increases, the efficiency goes down due to reduced JSC and increased VOC loss. Therefore, understanding the loss mechanism and corresponding solutions need to be developed. Scaling up the device's active area without compromising the fill factor and, hence, efficiency is non-trivial. So, understanding the loss mechanism in large area devices is crucial. The stability analysis reported in the literature is inconsistent, preventing data comparison and identifying various degradation factors or failure mechanisms. Moreover, how the accelerated tests would be useful in predicting the real lifetime of the solar cells is yet to be developed. So, understanding the knowledge and the technological gaps between laboratory and industry-scale production is crucial for further development. Therefore, in this review article, we discuss the challenges and opportunities for scalable and stable high efficiency PSCs.
Dynamics of non-Newtonian fluid–fiber interactions and void formation mechanism based on fused filament fabrication
Authors: Guo Pengyue , Wu Jiang , Zhang Hao , Ji Jingbo , An Xizhong , Yang Dongmin
Published: October 2024

Due to the presence of internal defects such as voids in the composites manufactured by material extrusion additive manufacturing (MEX AM), the mechanical properties of the composites are significantly below the theoretical optimum. Under this circumstance, this paper is intended to investigate the effects of nozzle feeding angles and to analyze the void formation and evolution of multiphase flow, in which systematic computational fluid dynamics numerical simulations are conducted. The volume of fluid model and overset grid method are used to simulate the extrusion deposition process of carbon fiber-reinforced polymer composites, and the Carreau model is used to represent the shear-thinning behavior of molten polymer. The numerical method is validated against previously experimental and numerical simulation data. The numerical results show that the key factor leading to void formation is the vortices caused by fiber oscillation. The intense vortex at the front end of the fibers disrupts the interface between molten polymer and air, creating a beneficial condition for air to enter. Nozzle tilting can effectively reduce the probability of void formation by decreasing the fiber oscillation velocity. The results of the present study provide insights into the development and optimization of printer nozzles to enable the printing of longer fibers with less probability of potential void formation.
Marangoni-driven pattern formation in an absorbing binary mixture
Authors: Arroiabe P. F. , Martinez-Agirre M. , Nepomnyashchy A. , Bou-Ali M. M. , Shevtsova V.
Published: October 2024

We investigate the evolution of convective instability in a LiBr–water binary mixture, driven by thermal and solutal Marangoni stresses, through numerical simulations. A small perturbation in absorption at the surface disturbs the equilibrium, generating surface tension gradients that drive Marangoni flows. To isolate and better understand the interplay between the Marangoni effect and absorption, we extended the previous study by investigating the LiBr–water binary system in the absence of gravity. For the first time, we observed the formation of a stable rim in an absorbing binary mixture, which underwent a slight contraction followed by rapid Marangoni spreading. This behavior shows similarities with the flow patterns seen in the “coffee-ring” and Marangoni spreading phenomena in evaporating binary mixtures. On the subsurface, convective motion breaks into several vortices, accompanied by the formation of plumes with reduced mass fraction. As the system evolves, the symmetry of the flow pattern around the cell center breaks down. The absence of buoyancy-driven forces eliminates a key counterforce to Marangoni flows, transforming the previously ordered patterns into non-periodic oscillations, followed by the development of non-stationary but regular patterns. These results complement our earlier findings [P. F. Arroiabe et al., Phys. Fluids 36, 022119 (2024)] where gravitational forces obscured these phenomena.
Near-field wake dynamics of propellers affected by double-sided barnacles attachment
Authors: Wang Zhengren , Wu Tiecheng , Wang Lianzhou , Cao Weitao , Luo Wanzhen
Published: October 2024

This study employs the improved delayed detached-eddy simulation method for detailed numerical simulations to investigate the impact of barnacle attachment on the hydrodynamic performance of propellers. The simulations were conducted on an unstructured grid comprising 50.7 × 106 cells, ensuring high fidelity in capturing complex flow phenomena. The study examines the near-field evolution of the propeller wake, focusing on the changes in vortex structures and flow characteristics caused by barnacle attachment. The results indicate that barnacles not only reduce the propeller's propulsion efficiency but also significantly alter the topology of tip vortices, leading to increased turbulence intensity. The simulations also reveal the mechanism by which barnacles affect the hydrodynamic performance of the propeller, notably by significantly altering the flow direction around the blades, exacerbating flow separation and the generation of localized vortices. In addition to affecting normal thrust generation, the interaction between small-scale vortices and tip vortices further destabilizes the tip vortices. These findings provide insight into the complex flow interactions in marine environments and their impact on propeller efficiency and durability.
Medicare-reimbursed psychiatric consultations before and after telehealth expansion in Australia: a time series study
Authors: Woon Luke Sy-Cherng , Maguire Paul A. , Reay Rebecca E. , Mittinty Murthy , Bastiampillai Tarun , Looi Jeffrey C. L.
Published: October 2024

Objective Telepsychiatry consultations grew rapidly with increased total consultations and reduced face-to-face consultations following the pandemic-triggered expansion of Medicare Benefits Schedule (MBS) telehealth items. It was unclear how much telehealth expansion independently impacted overall and face-to-face consultation trends after accounting for lockdown severity. Methods We extracted monthly MBS Item Reports for psychiatric consultations (January 2012–December 2023). The monthly average Stringency Index (SI) for Australia represented lockdown severity from January 2020 to December 2022. A dichotomous variable denoted telehealth expansion (March 2020 onward). We constructed consecutive multiple linear regression models for combined consultations and face-to-face consultations to include seasonality, trend, SI, and telehealth expansion. We compared model performance using information criteria. Results Median monthly total consultations increased from 148,413 (Interquartile range, IQR: 138,219–153,709) pre-expansion (January 2012–February 2020) to 173,016 (IQR: 158,292–182,463) post-expansion (March 2020–December 2023). Contrarily, median monthly face-to-face consultations decreased from 143,726 (IQR: 135,812–150,153) to 99,272 (IQR: 87,513–107,778). Seasonality and trend were present in both time series. The time series regression model with expansion but excluding SI best explained all consultations, while both telehealth expansion and SI were significant in the best-fit model for face-to-face consultations. Conclusion MBS telehealth expansion was associated with total and face-to-face consultations independent of lockdown severity changes. Policy changes allowing wider access to new telehealth services have possibly led to increased uptake of psychiatric care and addressed previously unmet needs.
GAMBUT field measurement of emissions from a tropical peatland fire experiment: from ignition to spread to suppression
Authors: Hu Yuqi , Smith Thomas E. L. , Santoso Muhammad A. , Amin Hafiz M. F. , Christensen Eirik , Cui Wuquan , Purnomo Dwi M. J. , Nugroho Yulianto S. , Rein Guillermo
Published: October 2024

Background Accurate quantification of emissions from peatland wildfire is crucial for understanding their feedback to the atmospheric and Earth system. However, current knowledge on this topic is limited to a few laboratory and field studies, which report substantial variability in terms of the fire emission factors (EFs). Aims We aim to understand how emissions vary across the life cycle of a peatland fire. Methods In August/September 2018, we conducted the largest and longest to-date field-scale experimental burn on a tropical peatland in Sumatra, Indonesia. Field measurements of gas emissions from the fire experiment were conducted using an open-path Fourier transform infrared spectroscopy to retrieve mole fractions of 11 gas species. Key results For the first time, we calculated and reported EFs from 40 measurement sessions conducted over 2 weeks of burning, encompassing different fire stages (e.g. ignition, smouldering spread, and suppression) and weather events (e.g. rainfall). Our findings provide field evidence to indicate that EFs vary significantly among fire stages and weather events. We also observed that the heterogeneous physicochemical properties of peatland site (e.g. moisture content) influenced the EFs. We also found that modified combustion efficiency was highly sensitive to complex field variables and could introduce large uncertainties when determining the regimes of a peat fire. Conclusions and implications Further studies to investigate peat fire emissions are needed, and more comprehensive mapping of peatland heterogeneity and land use for emissions inventories, accounting for spatial and temporal variability in EFs since the initiation of a fire event is required.
Spatiotemporal responses of ungulates to hunting in a fenced multi-use area
Authors: van Roekel Koen M. , Snijders Lysanne , Visscher Darcy R.
Published: October 2024

Context Human activities, such as tourism and hunting, affect the spatiotemporal behaviour of wildlife. For example, it is well documented that ungulates change their spatiotemporal behaviour as a response to hunting pressure, but less is known about ungulate responses to hunting in areas where human activity is common throughout the year and ungulates are constrained by fences. Aims In this camera-trap study, we analysed the change in spatiotemporal behaviour of wild ungulates (elk, Cervus canadensis (3519 events), moose, Alces alces (1153 events), and white-tailed deer, Odocoileus virginianus (2708 events)) in response to the hunting period in a recreational and fenced park, the Cooking Lake–Blackfoot Provincial Area, Canada. Methods We used general linear models to compare species-specific patterns of intensity of use, calculated as events per week, in response to changes in the nature of human disturbance, namely a shift from recreation to hunting activity. In particular, we compared intensity of use in and out of the hunting season to determine whether species engaged in spatial patterns of avoidance with respect to hunting. We used daily and seasonal patterns of activity to determine how ungulates shifted their temporal use in response to hunting activity and whether they became more nocturnal as a result. Key results We found that ungulates responded temporally to the hunting period by generally shifting their activity to more nocturnal hours, with white-tailed deer showing the biggest temporal shift, suggesting that the ungulates distinguish between consumptive and non-consumptive human activities. Nevertheless, temporal overlap between humans and all ungulate species increased during the hunting period as humans targeted times of increased ungulate activity. Spatially, the response was less distinctive and was species-specific. Elk showed little change in spatial behaviour in response to the hunting period. In contrast, moose decreased the use of trail areas and other areas frequented by humans, whereas deer, counterintuitively, increased the use of trail areas, albeit their use became much more nocturnal. Conclusions We have shown that responses of ungulates to hunting exceed those to non-consumptive recreational use, and whereas temporal responses (increased nocturnality) were consistent across ungulate species, spatial responses were species-specific. Implications Management in small fenced multi-use areas needs to account for shifts in the intensity of disturbance resulting from a change in human disturbance from recreational activity to hunting. Providing spatial opportunities for avoidance of humans is key for most species if hours of operation in these areas already limit the timing of human activity.
Artificial light at night reveals hotspots and rapid development of industrial activity in the Arctic
Authors: Akandil Cengiz , Plekhanova Elena , Rietze Nils , Oehri Jacqueline , Román Miguel O. , Wang Zhuosen , Radeloff Volker C. , Schaepman-Strub Gabriela
Published: October 2024

Climate warming enables easier access and operation in the Arctic, fostering industrial and urban development. However, there is no comprehensive pan-Arctic overview of industrial and urban development, which is crucial for the planning of sustainable development of the region. In this study, we utilize satellite-derived artificial light at night (ALAN) data to quantify the hotspots and the development of light-emitting human activity across the Arctic from 1992 to 2013. We find that out of 16.4 million km
2
analyzed a total area of 839,710 km
2
(5.14%) is lit by human activity with an annual increase of 4.8%. The European Arctic and the oil and gas extraction regions in Russia and Alaska are hotspots of ALAN with up to a third of the land area lit, while the Canadian Arctic remains dark to a large extent. On average, only 15% of lit area in the Arctic contains human settlement, indicating that artificial light is largely attributable to industrial human activity. With this study, we provide a standardized approach to spatially assess human industrial activity across the Arctic, independent from economic data. Our results provide a crucial baseline for sustainable development and conservation planning across the highly vulnerable Arctic region.
Receptor usage of Syncytin-1: ASCT2, but not ASCT1, is a functional receptor and effector of cell fusion in the human placenta
Authors: Štafl Kryštof , Trávníček Martin , Janovská Anna , Kučerová Dana , Pecnová Ľubomíra , Yang Zhiqi , Stepanec Vladimír , Jech Lukáš , Salker Madhuri S. , Hejnar Jiří , Trejbalová Kateřina
Published: October 2024

Syncytin-1, a human fusogenic protein of retroviral origin, is crucial for placental syncytiotrophoblast formation. To mediate cell-to-cell fusion, Syncytin-1 requires specific interaction with its cognate receptor. Two trimeric transmembrane proteins, Alanine, Serine, Cysteine Transporters 1 and 2 (ASCT1 and ASCT2), were suggested and widely accepted as Syncytin-1 cellular receptors. To quantitatively assess the individual contributions of human ASCT1 and ASCT2 to the fusogenic activity of Syncytin-1, we developed a model system where the
ASCT1
and
ASCT2
double knockout was rescued by ectopic expression of either ASCT1 or ASCT2. We demonstrated that ASCT2 was required for Syncytin-1 binding, cellular entry, and cell-to-cell fusion, while ASCT1 was not involved in this receptor interaction. We experimentally validated the ASCT1–ASCT2 heterotrimers as a possible explanation for the previous misidentification of ASCT1 as a receptor for Syncytin-1. This redefinition of receptor specificity is important for proper understanding of Syncytin-1 function in normal and pathological pregnancy.
WDR20 prevents hepatocellular carcinoma senescence by orchestrating the simultaneous USP12/46-mediated deubiquitination of c-Myc
Authors: Jiang Li , Qi Xuxin , Lai Minshan , Zhou Jiahao , Yuan Meng , You Jieqiong , Liu Qiang , Pan Jinchang , Zhao Luyao , Ying Meidan , Ji Junfang , Li Ke , Zhang Yan , Pan Weiwei , He Qiaojun , Yang Bo , Cao Ji
Published: October 2024

The dysfunction of the ubiquitin–proteasome system (UPS) facilitates the malignant progression of hepatocellular carcinoma (HCC). While targeting the UPS for HCC therapy has been proposed, identifying effective targets has been challenging. In this study, we conducted a focused screen of siRNA libraries targeting UPS-related WD40 repeat (WDR) proteins and found that silencing WDR20, a deubiquitinating enzyme activating factor, selectively inhibited the proliferation of HCC cells without affecting normal hepatocytes. Moreover, the downregulation of WDR20 expression induced HCC cellular senescence and suppressed tumor progression in xenograft, sleeping beauty transposon/transposase, and hydrodynamic tail vein injection-induced HCC models, and
Alb-Cre
+
/
MYC
+
HCC transgenic mouse models. Mechanistically, we found that WDR20 silencing disturbed the protein stability of c-Myc, orchestrating the simultaneous USP12/46-mediated deubiquitination of c-Myc, thereby promoting the transcriptional activation of
CDKN1A
. Further investigation revealed a positive coexpression of WDR20 and c-Myc in a tissue microarray with 88 HCC clinical samples. By employing three patient-derived organoids from individuals with HCC, we have validated the decrease in c-Myc expression and the significant induction of senescence and growth inhibition following silencing of WDR20. This study not only uncovers the biological function of WDR20 and elucidates the molecular mechanism underlying its negative regulation of HCC cellular senescence but also highlight the potential of WDR20 as a promising target for HCC therapy.
Ecological change increases malaria risk in the Brazilian Amazon
Authors: Arisco Nicholas J. , Peterka Cassio , Diniz Cesar , Singer Burton H. , Castro Marcia C.
Published: October 2024

Ecological change in the Brazilian Amazon is closely linked to human mobility and health. Mining, agriculture, logging, and other activities alter highly diverse ecological and demographic contexts and subsequent exposure to diseases such as malaria. Studies that have attempted to quantify the impact of deforestation on malaria in the Brazilian Amazon have produced conflicting results. However, they varied in methodology and data sources. Most importantly, all studies used annual data, neglecting the subannual seasonal dynamics of malaria. Here, we fill the knowledge gap on the subannual relationship between ecological change in the Brazilian Amazon and malaria transmission. Using the highest spatiotemporal resolution available, we estimated the effect of deforestation on malaria cases between 2003 and 2022 using a stratified Bayesian spatiotemporal hierarchical zero-inflated Poisson model fitted with the Integrated Nested Laplace Approximation. The model was also stratified by state. We found that a 1% increase in 1-mo lagged deforestation increased malaria cases in a given month and municipality by 6.3% [95% credible interval (Crl): 6.2, 6.5%]. Based on an interaction term included in the model, the effect of deforestation on malaria was even larger in areas with higher forest cover. We found that the coefficients for deforestation and mobility were highly variable when stratified by state. Our results provide detailed evidence that, on average, deforestation increases malaria transmission, but that the relationship is not spatiotemporally uniform. These results have implications for stratifying malaria control interventions based on ecological dynamics to help Brazil achieve its goal of malaria elimination by 2035.
NFAT5 governs cellular plasticity-driven resistance to KRAS-targeted therapy in pancreatic cancer
Authors: Deng Daiyong , Begum Habeebunnisa , Liu Tong , Zhang Jiangyan , Zhang Qiang , Chu Ting-yu , Li Hong , Lemenze Alexander , Hoque Mainul , Soteropoulos Patricia , Hou Pingping
Published: October 2024

Resistance to KRAS therapy in pancreatic ductal adenocarcinoma (PDAC) involves cellular plasticity, particularly the epithelial-to-mesenchymal transition (EMT), which poses challenges for effective targeting. Chronic pancreatitis, a known risk factor for PDAC, elevates TGFβ levels in the tumor microenvironment (TME), promoting resistance to KRAS therapy. Mechanistically, TGFβ induces the formation of a novel protein complex composed of SMAD3, SMAD4, and the nuclear factor NFAT5, triggering EMT and resistance by activating key mediators such as S100A4. Inhibiting NFAT5 attenuates pancreatitis-induced resistance to KRAS inhibition and extends mouse survival. Additionally, TGFβ stimulates PDAC cells to secrete CCL2, recruiting macrophages that contribute to KRAS bypass through paracrine S100A4. Our findings elucidate the role of TGFβ signaling in EMT-associated KRAS therapy resistance and identify NFAT5 as a druggable target. Targeting NFAT5 could disrupt this regulatory network, offering a potential avenue for preventing resistance in PDAC.
Finding NEMO in the thymus
Authors: Ocampo-Godinez Juan Moises , Kreins Alexandra Y.
Published: October 2024

Rosain et al. (https://doi.org/10.1084/jem.20231152) describe the association between anti-type I interferon autoantibodies and severe viral infections in patients with incontinentia pigmenti and heterozygous loss-of-function NEMO variants, suggesting a role for canonical NF-κB signaling in immune tolerance. The mechanisms behind this selective autoimmunity remain unclear.
Electrical and optical characteristics of a nanosecond pulsed electrical discharge in air in contact with a water droplet for various electrical conductivities
Authors: Sebih Lyes , Carbone Emile , Hamdan Ahmad
Published: October 2024

Interactions between pulsed electrical discharges and liquid dielectric materials have emerged as a growing research field with interests in fundamental discharge physics and subsequent applications. Herein, we present an experimental study on the dynamics of nanosecond discharges in air in the presence of a water droplet with various electrical conductivities (EC) and at different applied voltages (V
a). The discharges are characterized optically, by employing time-resolved ICCD imaging and optical emission spectroscopy, and electrically, by acquiring the current–voltage waveforms for every discharge. The results show that three modes of discharge can be obtained: i) streamer discharge between the cathode and the droplet, ii) streamer discharge between the cathode and the droplet as well as between the anode and the droplet, and iii) spark discharge that connects the two electrodes and propagates over the droplet. We find that the probability to obtain one of the three discharge modes is strongly related to the droplet’s EC and V
a. Although the streamer’s ignition is relatively insensitive to EC, its transition to a spark can be finely controlled by the droplet’s EC. Time-resolved ICCD images show that the discharge initiates in the gap between the cathode and the droplet, followed by ignition between the anode/ground electrode and the droplet. Next, an extinction phase is observed before the ignition of a secondary streamer. Depending on the conditions, the discharge may transition to a spark, that is a channel with high emission intensity. We find that the duration of each stage of discharge propagation and the corresponding emission (path and intensity) are sensitive to the droplet’s EC. Finally, emissions from streamers (primary and secondary) and from sparks are analyzed using optical spectroscopy. We find that the emission from the streamers is dominated by the second positive system of N2, and that the droplet’s EC does not significantly affect the emission spectra nor the estimated rotational temperature of N2.
Low-rank rotation matrices-based DOA estimation with a moored circular vector sensor array
Authors: Liu Guolong , Li Ying , Wang Jinjin , Lan Tian , Qiu Longhao , Liang Guolong
Published: October 2024

Water currents affect circular vector sensor arrays (CVSAs) suspended from a moored platform, causing them to rotate underwater. This rotation alters the direction of sources within the array coordinate system over time. Traditional methods that rely on numerous snapshots often yield inaccurate results, particularly for faint sources. To improve the accuracy, we introduce a direction-finding technique for CVSAs that employs low-rank rotation matrices (RM). The low-rank RM are constructed using the heading information of the CVSAs and the subregion array manifold vector matrices to achieve spatial focusing. When these matrices are applied to the measurement data, the resulting covariance matrix displays subspace characteristics similar to that of a stationary CVSA. Our performance analysis revealed that low-rank RM offer higher focusing gains than conventional RM. The method proposed in this study effectively improves the direction estimation performance for weak targets and extends the practical applicability of measurement techniques for rotating platforms. Both simulations and experiments confirm that our approach outperforms the modified traditional beamforming and other spatial focusing techniques in terms of resolution and precision. Notably, when the signal-to-noise ratio is below −4 dB, the resolution for distinguishing between the two sources increases by more than 50%.
Two types of corner states in two dimensional photonic crystals with finite sizes
Authors: Zhang Zirui , Yao Yongxi , Zhang Yu , Zhao Bao , Zhang Hongfang , Shi Qiang , Yang Bing
Published: October 2024

Using two-dimensional square lattice photonic crystals (PCs) with different topological properties, we design different combined structures to construct two types of topological corner states (CSs), named as Type I and Type II CSs. Then by tuning sizes of inner PCs in the combined structures, we systematically investigate size effects on the two types of CSs. Numerical results demonstrate as the structures decrease to their critical sizes, due to the interactions of opposite interfaces and the couplings of corners, size changes of inner PCs in the combined structures have significant effects on the frequencies, degeneracies and mode field distributions of the two types of CSs. Moreover, Type I CSs peform better topological stability than Type II CSs during the size changes of structures. We also monitor mode field localizations of the two types of CSs and reveal that their localizations are only related to the types of the CSs, and have no relations to sizes and overall symmetries of the combined structures. Our research enriches the study of higher order topological CSs and paves the way for design and manufacture of optical micro–nano devices with photonic topological CSs.
Andreev reflection in topological nodal-line semimetals superconductor junction
Authors: Cheng Xue-Yan , Yang Ning-Xuan , Wang Rui , Liao Hui , Song Chun-Yan , Song Ting-Ting
Published: October 2024

Andreev reflection is an important quantum tunneling phenomenon in the conductor-superconductor junction. The Andreev reflection coefficients T
AR of a hybrid system with s-wave superconductor connected by topological nodal-line semimetals (TNLSMs-SC junction system) is calculated theoretically by using the Landauer–Büttiker formula combined with the nonequilibrium Green’s function method. The results show that when the direction of the boundary state electron and the incident electron are the same, only the bulk states of the TNLSMs involve the Andreev reflection of the hybrid system, and the Andreev reflection coefficients T
AR enhance with the increase of the Fermi energy

E
F

. We also study the effect of on-site energy ε

z
and mass term m on the Andreev reflection and find that the Andreev reflection in the system decreases rapidly with the increase of on-site energy ε

z
and mass term m. Moreover, we find that only in the presence of a mass term m, the Andreev reflection coefficients T

AR
of the system changes with the rise of the Fermi energy EF
. When a perpendicular magnetic field is applied in the system, the Andreev reflection coefficients T
AR in the superconducting gap will appear a series of oscillating peaks. For a hybrid system with the large perpendicular magnetic field applied, we find that the maximum Andreev reflection coefficients

T

AR

=
7.2

at the Fermi energy

E
F

=
0.0

and the incident electron energy

E
=
±
0.1

. The Andreev reflection coefficients T
AR is gradually enhanced in the superconducting gap (incident energy

|
E

|

⩽
0.2

) when a disorder is applied to the superconductor region of the system. However, the symmetry of the Andreev reflection coefficients T
AR is broken when the perpendicular magnetic field is applied to the system. These peculiar transport properties of the TNLSMs-SC junction system are expected to provide theoretical guidance for future applications.
Photon blockade in a high-damping cavity via a gain-type coupler
Authors: Li Shiyan , Wang Nan , Zhu Ai-Dong , Zhang Da-Wei
Published: October 2024

We propose a scheme to implement photon blockade in a non-Hermitian circuit quantum electrodynamics (circuit-QED) system where a single-mode cavity interacts with a two-level emitter through virtual photon excitation mediated by a coupler resonator. A damping compensation regime is introduced by the phase-lag arising from the medium mode, thereby the periodic exceptional points (EPs) are observed at which the system achieves gain-damping balance. This regime enables photon blockade to occur within the single-mode cavity with high-damping rate by controlling the gain circuit of the coupler, which breaks the limitation of a low-damping rate for photon blockade under weak drive and relaxes the stringent requirements on the quality factor of the cavity. The numerical simulations for the second-order correlation function, obtained using reported experimental parameters, exhibit excellent agreement with our analytical results. The findings of this study provide a circuit-QED solution for single-quantum devices based on the high-damping cavities, which is of great significance for integrated quantum computing networks.
System response time and optimal path
Authors: Melgarejo Augusto , Langoni Laura , Ruscitti Claudia
Published: October 2024

In this work we study, in general terms, the optimal path for an out-of-equilibrium process from a geometric perspective constructed from a probability density function belonging to the exponential family (PDFE). With this objective we have constructed the speed of entropy production for a system out of equilibrium. This speed of entropy production is not determined with respect to the clock time t but rather with respect to a dimensionless time

ξ

t

associated with a characteristic response time of each system

λ

t

.

In this context, we demonstrate that the constant entropy production speed condition leads to the system moving on a geodesic of the manifold constructed from the probability density function. In the last part of this work we apply our general results to study the Ornstein–Uhlenbeck process (OU), which is a well-known stochastic process that strictly speaking describes the velocity of a Brownian particle under the influence of friction. As the system evolves we find that dimensionless time

ξ

t

passes slower than clock time t.
Structural, electronic, optical, mechanical, and phononic bulk properties of tetragonal trirutile antimonate MSb2O6 (M = Fe, Co, Ni, or Zn): a first-principles prediction for optoelectronic applications
Authors: Charif Rania , Makhloufi Rachid , Mouna Sarah Chaba , Chadli Abdelhakim , Barkat Ayoub , Nouiri Mourad
Published: October 2024

This work does an extensive analysis of the optoelectronic and mechanical properties of the tri rutile structure type 3d transition metal Antimonate MSb2O6 (M = Fe, Co, Ni, or Zn), for the first time, utilizing the pseudo-potential plane wave approach within the density functional theory framework. When calculating the structural, optical, and mechanical properties, the exchange–correlation interactions were studied using the GGA-PBE functional, whereas when computing electronic, it is analyzed using the HSE06 hybrid functional. The equilibrium lattice parameters exhibit good agreement with the available experimental results. The electronic properties were estimated using the GGA-PBE and HSE06 functionals. Based on the calculated electronic properties with the GGA-PBE functional, the FeSb2O6, CoSb2O6, and NiSb2O6 materials exhibit metallic behavior with energy gap values of 0 eV, while ZnSb2O6 is a semiconductor with a narrow direct band gap (Γ–Γ) of 0.5 eV. Furthermore, the computed band gaps using the HSE06 functional are 0 eV, 0 eV, 1 eV (Γ–Γ), and 4 eV (Γ–Γ) for FeSb2O6, CoSb2O6, NiSb2O6, and ZnSb2O6, respectively. Density of states diagrams were used to gain deeper insights into the characteristics of the energy bands. The optical properties of these compounds, such as the dielectric function, energy loss function, conductivity, reflectivity, refractive index, and absorption coefficient were investigated over the energy range of 0 to 40 eV. The materials exhibited a high absorption coefficient and a significantly low reflectivity within the UV–vis energy spectrum. The negative cohesive energy Ecoh implies the chemical (thermodynamic) stability of the trirutile MSb2O6 (M = Fe, Co, Ni, or Zn). Mechanical stability is confirmed by applying the Born stability criteria using elastic constants (Cij). The absence of imaginary frequencies in the phonon spectrum calculations confirms the dynamic stability of the studied compounds. These results are consistent with previous experimental research on these materials in photocatalysis and gas sensor applications. On the other hand, these compounds possess exceptional high and broad optical absorption UV range, making them suitable for use in next-generation ultraviolet photodetectors.
Entropy-based geometric measures of correlations for bell diagonal states via measurement
Authors: Liu Yutong , Nan Hua , Zhang Lin , Jin Yan , Hong Yicheng
Published: October 2024

The classification and quantification of quantum correlations are the important issues in quantum information theory. Quantum relative entropy and Rényi relative entropy are both non-negative, and can therefore be regarded as generalized distances between quantum states. We first introduced the method proposed by Brodutch and Modi for constructing measurements of classical and quantum correlations. Subsequently, we use this method to construct measurement-induced geometric classical and quantum correlations based on quantum relative entropy and Rényi−

1

2

relative entropy. For two-qubit Bell diagonal states, the analytic expressions for these geometric classical correlations and quantum correlations are obtained.
Variability in individual native fibrin fiber mechanics
Authors: Helms Christine C
Published: October 2024

Fibrin fibers are important structural elements in blood coagulation. They form a mesh network that acts as a scaffold and imparts mechanical strength to the clot. A review of published work measuring the mechanics of fibrin fibers reveals a range of values for fiber extensibility. This study investigates fibrinogen concentration as a variable responsible for variability in fibrin mechanics. It expands previous work to describe the modulus, strain hardening, extensibility, and the force required for fiber failure when fibers are formed with different fibrinogen concentrations using lateral force atomic force microscopy. Analysis of the mechanical properties showed fibers formed from 1 mg ml−1 and 2 mg ml−1 fibrinogen had significantly different mechanical properties. To help clarify our findings we developed two behavior profiles to describe individual fiber mechanics. The first describes a fiber with low initial modulus and high extensible, that undergoes significant strain hardening, and has moderate strength. Most fibers formed with 1 mg ml−1 fibrinogen had this behavior profile. The second profile describes a fiber with a high initial modulus, minimal strain hardening, high strength, and low extensibility. Most fibrin fibers formed with 2 mg ml−1 fibrinogen were described by this second profile. In conclusion, we see a range of behaviors from fibers formed from native fibrinogen molecules but various fibrinogen concentrations. Potential differences in fiber formation are investigated with SEM. It is likely this range of behaviors also occurs in vivo. Understanding the variability in mechanical properties could contribute to a deeper understanding of pathophysiology of coagulative disorders.
Wavemeter calibration by frequency comb
Authors: Egan Patrick F
Published: October 2024

Upgrades to the vacuum wavelength calibration service at the National Institute of Standards and Technology are reported. The instrumentation centerpiece is an optical frequency comb stabilized to a GPS-disciplined oscillator, thereby providing direct traceability to the SI second. Historically, the service has covered lasers at the popular interferometry wavelengths red and green. Recently, capability has been added for calibrating wavemeters at multiple telecom wavelengths in the range

(
1520
<
λ
<
1570
)
 
nm

. For most commercially available wavemeters, the test uncertainty ratio is about 104.
Experimental study on enhancing pedestrian efficiency and crowd safety with regular sound under open boundaries
Authors: Fu Zhijian , Wei Pengchen , Chen Cheng , Luo Lin , Yuan Zhilu , Li Jian
Published: October 2024

We empirically investigated the impact of regular sound on planar pedestrian movement in open boundary environments, a rarely studied topic. Participants walked to regular sound with different tempos (70 BPM vs. 100 BPM) and types (monotone vs. periodic ‘tick-tack’ rhythm). We found that regular sounds at 100 BPM, close to the normal walking pace, improve pedestrian efficiency. They reduce passing time by 8.41% and increase average flow by 9.50%. This efficiency enhancement is lower compared to single-file experiment with periodic boundaries, where reaching a high-density jammed phase is easier. Additionally, this efficiency enhancement from sound is reduced by unstable step synchronization under open boundaries and turning behavior. Regular sound significantly improves crowd safety in turning areas, where congestion levels (Cls) and crowd danger (Cd) are highest. Cls decrease by 8.27% with the 100 BPM monotone, and Cd decreases by 19.1% with the 100 BPM periodic rhythm. Operationally, regular sounds at 100 BPM can be used to guide pedestrian flow smoothly and effectively in crowd management.
An exactly solvable model for non-Fickian transport in dynamically heterogeneous media
Authors: Kim Ji-Hyun
Published: October 2024

Diffusion, observed in various condensed phases, finds its theoretical background in Einstein’s theory of Brownian motion, characterized by the linear time-dependence of mean square displacement (MSD) denoting Fickian behavior and the Gaussian distribution of particle displacement. Nevertheless, diverse systems exhibit either non-linear, non-Fickian time-dependence of the MSD or non-Gaussian displacement distribution. Montroll and Weiss’s continuous-time random walk (CTRW) model and the stochastic diffusivity (SD) model have provided insights into anomalous diffusion phenomena and Fickian-yet-non-Gaussian transport in dynamically heterogeneous environments, respectively. Building upon these approaches, Song et al developed a generalized transport equation with an environment-dependent diffusion kernel, providing a quantitative explanation for non-Fickian MSD and non-Gaussian displacement distribution. Based on the generalized transport equation, this study introduces an exactly solvable model for a non-Gaussian displacement distribution, accommodating arbitrary time profiles in its MSD, including both Fickian and non-Fickian behaviors. Our findings confirm the model’s capability in describing such transport processes. Furthermore, the proposed model unifies the CTRW model under fast environmental fluctuations and the SD model under Fickian time dependencies, making it suitable for understanding tracer particle motion within explicit solvent or complex media.
Generalized hydrodynamics and approach to generalized Gibbs equilibrium for a classical harmonic chain
Authors: Pandey Saurav , Dhar Abhishek , Kundu Anupam
Published: October 2024

We study the evolution of a classical harmonic chain with nearest-neighbor interactions starting from domain wall initial conditions. The initial state is taken to be either a product of two Gibbs ensembles (GEs) with unequal temperatures on the two halves of the chain or a product of two generalized Gibbs ensembles (GGEs) with different parameters in the two halves. For this system, we construct the Wigner function and demonstrate that its evolution defines the generalized hydrodynamics (GHD) describing the evolution of the conserved quantities. We solve the GHD for both finite and infinite chains and compute the evolution of conserved densities and currents. For a finite chain with fixed boundaries, we show that these quantities relax as

∼

1

/

t

to their respective steady-state values given by the final expected GE or GGE state, depending on the initial conditions. Exact expressions for the Lagrange multipliers of the final expected GGE state are obtained in terms of the steady-state densities. In the case of an infinite chain, we find that the conserved densities and currents at any finite time exhibit ballistic scaling while, at infinite time, any finite segment of the system can be described by a current-carrying non-equilibrium steady state (NESS). We compute the scaling functions analytically and show that the relaxation to the NESS occurs as

∼

1

/

t

for the densities and as

∼

1

/

t
2

for the currents. We compare the analytical results from hydrodynamics with those from exact microscopic numerics and find excellent agreement.
Analysis of cooperative cooling performance between the battery and cabin of pure electric vehicles
Authors: Tang Rongjiang , Guan Lei , Xu Chen , Shi Fangjian , Lu ZengJun , Nong Donghua
Published: October 2024

The cooperative cooling of the cabin and battery in pure electric vehicles (PEVs) is crucial for the comfort, thermal safety of the occupants, and the lifespan of the batteries. Therefore, a well-designed thermal management system (TMS) is particularly important. Thus, this paper constructs an cooperative cooling for the battery pack circuit and the cabin circuit in parallel, aiming to enhance the vehicle system’s integration and reduce energy consumption. Firstly, a one-dimensional simulation model of the cooperative TMS is established, and the model is calibrated through experiments. Subsequently, the system’s performance is analyzed under different ambient temperatures. The study finds that as the ambient temperature increases, the system’s energy consumption rises, and the Coefficient of Performance (COP) decreases. Moreover, when the system switches from the simultaneous cooling mode of the cabin and battery to the sole cooling mode of the cabin, the temperature of the cabin will fluctuate to a certain extent, within a range of 2°C. At same time, the COP value also increases with the switch of the mode. Finally, the analysis of the simultaneous cooling mode of the cabin and battery side under different ambient temperatures reveals that as the ambient temperature increases from 34°C to 42°C, the exhaust temperature, pressure ratio, and compressor speed increase accordingly, while the compressor efficiency decreases. The condenser and chiller experience a reduction in their heat transfer efficiency by 59.4 watts per degree Celsius and 218.5 watts per degree Celsius, respectively. Conversely, the evaporator’s heat transfer efficiency undergoes an enhancement of 6.77 watts per degree Celsius.
Analysis and research on the hydrodynamic performance of offshore floating photovoltaic systems under large tidal variations
Authors: Gao Xubing , Guo Jianting
Published: October 2024

This paper focuses on the multi-module connected offshore floating photovoltaic system, designing a mooring system with buoys, considering the effects of buoy size, position on the motion response of the photovoltaic system, mooring cable tension, and photovoltaic air gap. Based on the three-dimensional potential flow theory, optimal parameters for buoys were selected using regular waves at an average depth of 10 meters. Subsequently, factors such as tidal differences, randomness of waves, wind, and currents were taken into account, and the motion response, mooring tension, and photovoltaic air gap were calculated separately at water depths of 8 m, 10 m, and 12 m. The analysis results indicate that the offshore floating photovoltaic system with a buoy mooring system, under the influence of tidal differences, does not show significant differences in the minimum air-gap height of the photovoltaic system, ensuring safe and stable operation.