bluuebunny/crossref_metadata_2025 huggingface dataset:
NeuroRoots, a bio-inspired, seamless brain machine interface for long-term recording in delicate brain regions
Authors: Ferro Marc D. , Proctor Christopher M. , Gonzalez Alexander , Jayabal Sriram , Zhao Eric , Gagnon Maxwell , Slézia Andrea , Pas Jolien , Dijk Gerwin , Donahue Mary J. , Williamson Adam , Raymond Jennifer , Malliaras George G. , Giocomo Lisa , Melosh Nicholas A.
Published: August 2024

Scalable electronic brain implants with long-term stability and low biological perturbation are crucial technologies for high-quality brain–machine interfaces that can seamlessly access delicate and hard-to-reach regions of the brain. Here, we created “NeuroRoots,” a biomimetic multi-channel implant with similar dimensions (7 μm wide and 1.5 μm thick), mechanical compliance, and spatial distribution as axons in the brain. Unlike planar shank implants, these devices consist of a number of individual electrode “roots,” each tendril independent from the other. A simple microscale delivery approach based on commercially available apparatus minimally perturbs existing neural architectures during surgery. NeuroRoots enables high density single unit recording from the cerebellum in vitro and in vivo. NeuroRoots also reliably recorded action potentials in various brain regions for at least 7 weeks during behavioral experiments in freely-moving rats, without adjustment of electrode position. This minimally invasive axon-like implant design is an important step toward improving the integration and stability of brain–machine interfacing.
Physico-chemical characterization of cupola slag: Enhancing its utility in construction
Authors: Meshram S. S. , Raut S. P. , Giri Jayant , Sathish T. , Khan Salahuddin , Giri Pallavi
Published: August 2024

Cupola slag is a waste material of the steel and iron industries. Its composition is determined by the cupola furnace and other elements used in steel and iron manufacturing. This paper investigates the characterization behavior of various cupola slag materials. As a result, x-ray fluorescence (XRF), x-ray diffraction (XRD), thermogravimetry differential thermal analysis, and scanning electron microscopy (SEM) methods were used to characterize three cupola slag samples from distinct origins. In addition, various physical properties were used to compare different cupola slags. The specific gravity values of CS-1 (cupola slag-1 sample), CS-2 (cupola slag-2 sample), and CS-3 (cupola slag-3 sample) are 1.36, 2.5, and 2.917, respectively. The density and water absorption for CS-1, CS-2, and CS-3 are 1414.86, 1477.71, and 1796 kg/m3, and 0.37%, 0.32%, and 0.26%, respectively. Cupola slag also includes a larger percentage of lime, according to XRF data, which contributes to its improved binding characteristics. A higher calcium oxide content in CS-3 could facilitate the pozzolanic process. The presence of angular particles that aid in material binding is seen in the SEM image. Compounds with a nanostructure are then flawlessly blended into the mixture and grouped with calcium alumina silicates formed by cement hydration. The XRD pattern of cupola slag exhibits high peaks, indicating that the material is crystalline in character and can be utilized as sand. It also shows the presence of other chemical compounds, such as silica, which ranges from 30% to 45%. CS-1 and CS-2 have comparable XRD patterns. However, CS-3 has a somewhat different pattern because of the greater CaO content. Weight loss begins at higher temperatures, which shows that the material is stable at higher temperatures, according to a thermo-gravimetric study. The differential thermal analysis curve of CS-3 indicates that the material remains stable up to a temperature of 600 °C. The physical characteristics of all cupola slag samples show that cupola slag may be utilized to make sustainable building materials because of its lower specific gravity, density, and water absorption.
Inhibiting the imprint effect of the TiN/HZO/TiN ferroelectric capacitor by introducing a protective HfO2 layer
Authors: Yu Shihao , Zhang Yefan , Yang Peng , Luo Xiaopeng , Sun Zhenyuan , Liu Haijun , Liu Sen
Published: August 2024

Interfacial differences between the Hf0.5Zr0.5O2 (HZO) and the top/bottom electrodes caused by the process sequence could lead to the imprint effect of the TiN/HZO/TiN ferroelectric capacitor, which leads to serious reliability problems. In this article, a method of introducing a HfO2 protective layer is proposed to inhibit the imprint effect of the TiN/HZO/TiN ferroelectric capacitor. By introducing the HfO2 protective layer, the leakage current at the positive electric field is reduced by three orders of magnitude, the asymmetry of the coercive field is reduced from 1.5 to 0.1 MV/cm, and the endurance is improved by two orders of magnitude with no degradation in retention. The proposed method provides a feasible strategy to inhibit the imprint effect of TiN/HZO/TiN ferroelectric capacitors and is more compatible with complementary metal–oxide–semiconductor processes.
‘Data Deficient’ but potentially threatened: first biological observations on the poorly known quagga catshark (Halaelurus quagga)
Authors: Abisha Chinthamani , Dahanukar Neelesh , Ranjeet Kutty , Raghavan Rajeev
Published: August 2024

Context The quagga catshark (Halaelurus quagga) is a small-sized (~370-mm total length), deep-water catshark (Family: Pentanchidae), assessed as Data Deficient on the IUCN Red List. Aim We aimed to bridge critical knowledge gaps on aspects of the life history and exploitation of H. quagga to make a meaningful Red List assessment, and develop management plans. Methods Specimens landed as bycatch in three harbours along the Laccadive Sea coast of south-western India were examined to gather the first information on exploited length classes and aspects of reproductive biology. Key results Halaelurus quagga had a female-dominated sex ratio, a positively allometric growth in females, and isometric growth in males. Mature H. quagga males ranged between 294 and 336 mm, and females between 315 and 370 mm, with pregnant females carrying two, three or four egg cases with embryos in each uterus. Conclusions This study provides the first information on the biology and exploitation of H. quagga, showing that the species is landed (and discarded) as bycatch in trawl fisheries, with the catches comprising a significant amount of reproductively active individuals. Implications The intense deep-sea bottom-trawling off south-western India is a major threat to H. quagga, and, if left unmanaged, could likely trigger a threatened category on the IUCN Red List.
Spatiotemporal variations of precipitation patterns in the middle and lower reaches of Yangtze River Basin
Authors: Xiao Yang , Gu Ran , Zhou Qiang , Chen Mengyang , Zhang Taotao , Xu Chen , Zhu Zhenhong
Published: August 2024

Context With escalating global climate change, regional flood disasters have become increasingly prevalent. Precipitation, as a primary influencing factor, has garnered significant attention. Aims This study is based on precipitation data to investigate the spatiotemporal characteristics of precipitation in the middle and lower reaches of Yangtze River Basin (MLYB), trying to explore more concise methods for precipitation forecasting. Methods Statistical methods were employed to analyse historical precipitation patterns, followed by forecasting future trends using statistical time series models. Key results Precipitation in the MLYB exhibited a decreasing trend during 1961–2010, which shifted to an increasing trend after 2011, becoming more pronounced since 2017. Precipitation patterns in the MLYB were clearly increasing in the east and decreasing in the west, with the Taihu Basin showing the greatest rise. The ARIMA model predicted a significant increase in precipitation after 2022. Conclusions In recent years, precipitation in the MLYB has significantly increased, especially in downstream areas. Although the ARIMA model offers an effective and reasonably simple method for short-term forecast, it struggles with complex terrain influences. Implications These findings provide a theoretical basis for flood prevention in the MLYB, as well as a reference for precipitation prediction simulations in data-limited regions.
The intact and the imperilled: contrasting mammal population trajectories between two large adjacent islands
Authors: Neave Georgina , Murphy Brett P. , Rangers Tiwi , Andersen Alan N. , Davies Hugh F.
Published: August 2024

Context Native mammals continue to suffer widespread and severe declines across northern Australia’s tropical savannas. There is an increasing body of evidence that the primary driver of these declines is predation by feral cats (Felis catus) and that this is exacerbated by high-severity disturbance regimes (frequent high-intensity fires, and grazing and trampling by exotic megaherbivores) that simplify habitat, thereby increasing hunting efficiency. The large islands off the northern Australian coast – where some threats are either reduced or absent – provide a means of testing the conceptual model’s predictions. Aims To compare the trajectory and distribution of native mammal populations on two large, adjacent islands with markedly different disturbance regimes. Methods In 2020 and 2021, we resurveyed 111 historical sites across the two largest of the Tiwi Islands, Bathurst Island (42 sites) and Melville Island (69 sites) that were previously surveyed between 2000 and 2002. The Melville Island sites had also been resurveyed in 2015. We used the same live trapping method used in 2000–2002, supplemented with camera trapping. Key results On Bathurst Island, feral cats are rare, and we found no significant decrease in native mammal trap success or species richness, and the threatened brush-tailed rabbit-rat (Conilurus penicillatus melibius) appears stable. Conversely, cats occurred at relatively high abundance on Melville Island, and there was a 52% decline in trap success, a 47% reduction in species richness, and a 93% decline in trap success for the brush-tailed rabbit-rat over the 20-year period. The highest decreases in native mammal abundance and richness were in areas that were frequently burnt and had higher activity of feral cats. In contrast, in the absence of cats on Bathurst Island, native mammal abundance increased in frequently burnt areas. Conclusions While Bathurst Island remains one of Australia’s most important refuges for native mammals, neighbouring Melville Island is experiencing severe and ongoing mammal decline. We contend that this pattern primarily reflects the high abundance of cats on Melville Island compared to Bathurst Island. Implications Native mammal decline in northern Australian savannas is associated with abundant feral cats, but the relative contribution of disturbances in driving cat abundance remains less clear. An improved understanding of the constraints to feral cat populations in tropical savannas could enhance conservation management.
Fast and scalable ensemble learning method for versatile polygenic risk prediction
Authors: Chen Tony , Zhang Haoyu , Mazumder Rahul , Lin Xihong
Published: August 2024

Polygenic risk scores (PRS) enhance population risk stratification and advance personalized medicine, but existing methods face several limitations, encompassing issues related to computational burden, predictive accuracy, and adaptability to a wide range of genetic architectures. To address these issues, we propose Aggregated L0Learn using Summary-level data (ALL-Sum), a fast and scalable ensemble learning method for computing PRS using summary statistics from genome-wide association studies (GWAS). ALL-Sum leverages a L0L2 penalized regression and ensemble learning across tuning parameters to flexibly model traits with diverse genetic architectures. In extensive large-scale simulations across a wide range of polygenicity and GWAS sample sizes, ALL-Sum consistently outperformed popular alternative methods in terms of prediction accuracy, runtime, and memory usage by 10%, 20-fold, and threefold, respectively, and demonstrated robustness to diverse genetic architectures. We validated the performance of ALL-Sum in real data analysis of 11 complex traits using GWAS summary statistics from nine data sources, including the Global Lipids Genetics Consortium, Breast Cancer Association Consortium, and FinnGen Biobank, with validation in the UK Biobank. Our results show that on average, ALL-Sum obtained PRS with 25% higher accuracy on average, with 15 times faster computation and half the memory than the current state-of-the-art methods, and had robust performance across a wide range of traits and diseases. Furthermore, our method demonstrates stable prediction when using linkage disequilibrium computed from different data sources. ALL-Sum is available as a user-friendly R software package with publicly available reference data for streamlined analysis.
All-back-contact neutral-colored transparent crystalline silicon solar cells enabling seamless modularization
Authors: Park Jeonghwan , Lee Kangmin , Lee Jungtaek , Kim Dawon , Lee Myounghyun , Seo Kwanyong
Published: August 2024

Transparent solar cells (TSCs) hold substantial potential as continuous energy generators, enabling their use in situations where conventional devices may not be feasible. However, research aimed at modularizing TSCs for the purpose of regulating the overall voltage and current they produce, a critical step toward practical application, is still in its nascent stages. In this study, we explored a custom-designed, all-back-contact (ABC) configuration, which situates all electrical contacts on the rear side, to create glass-like transparent crystalline silicon (
c-
Si) solar cells and seamless modules. The ABC design not only demonstrates high power conversion efficiency (PCE) in solar cells but also ensures unobstructed visibility through transparent solar modules. Notably, ABC
-
transparent
c-
Si solar cells achieved a peak PCE of 15.8% while maintaining an average visible transmittance of 20%. Through seamlessly interconnecting the unit cells, the output voltage and power were systematically tuned from 0.64 V and 15.8 mW (for a 1 cm
2
-sized unit cell) to 10.0 V and 235 mW (for a 16 cm
2
-sized module). Furthermore, we successfully demonstrated the photocharging of a smartphone using a transparent ABC solar module.
Molecular mechanism and functional significance of Wapl interaction with the Cohesin complex
Authors: Yuan Xueying , Yan Lu , Chen Qinfu , Zhu Shukai , Zhou Xinyu , Zeng Ling-Hui , Liu Mingjie , He Xiaojing , Huang Jun , Lu Weiguo , Zhang Long , Yan Haiyan , Wang Fangwei
Published: August 2024

The ring-shaped Cohesin complex, consisting of core subunits Smc1, Smc3, Scc1, and SA2 (or its paralog SA1), topologically entraps two duplicated sister DNA molecules to establish sister chromatid cohesion in S-phase. It remains largely elusive how the Cohesin release factor Wapl binds the Cohesin complex, thereby inducing Cohesin disassociation from mitotic chromosomes to allow proper resolution and separation of sister chromatids. Here, we show that Wapl uses two structural modules containing the FGF motif and the YNARHWN motif, respectively, to simultaneously bind distinct pockets in the extensive composite interface between Scc1 and SA2. Strikingly, only when both docking modules are mutated, Wapl completely loses the ability to bind the Scc1-SA2 interface and release Cohesin, leading to erroneous chromosome segregation in mitosis. Surprisingly, Sororin, which contains a conserved FGF motif and functions as a master antagonist of Wapl in S-phase and G2-phase, does not bind the Scc1-SA2 interface. Moreover, Sgo1, the major protector of Cohesin at mitotic centromeres, can only compete with the FGF motif but not the YNARHWN motif of Wapl for binding Scc1-SA2 interface. Our data uncover the molecular mechanism by which Wapl binds Cohesin to ensure precise chromosome segregation.
Lessons from Iceland: Natural Disaster Planning and Response
Authors: Thanh Nguyen Phuong , Jiang Tianzhi , Tang Jinxuan , Ibrahim Zainub
Published: August 2024

This case study evaluates Iceland’s emergency response plans for mitigating the impact of natural disasters on tourists. Recent natural disasters, including earthquakes and volcanic eruptions from late 2023 to early 2024, are discussed to illustrate the implementation of these plans. The study outlines the main components of Iceland’s emergency response plan, highlighting the roles of government agencies, police districts, and tourism-related groups. It emphasizes the plan’s effectiveness in prioritizing the safety of tourists through evacuation procedures, mitigation measures, and coordination among stakeholders. Recommendations for improvement include the implementation of disaster aid insurance plans and regular reviews and adjustments to the emergency response plan. These recommendations aim to enhance preparedness and resilience in the face of future disasters.

Information

© The Authors 2024
Discriminating motilities: Coordinating IFT with flagellar beating patterns
Authors: Alves Aline Araujo , Bastin Philippe
Published: August 2024

Intraflagellar transport has traditionally been studied in immobilized flagella. In this issue, Gray et al. (https://doi.org/10.1083/jcb.202401154) introduced a novel methodology for fast imaging in free-swimming Leishmania, revealing the impacts of flagellum immobilization on intraflagellar transport and its inverse correlation with cell swimming speed.
A new fixed-time sliding mode control scheme for synchronization of chaotic systems
Authors: Wang Liangyu , Dong Wenjie , Ding Qun
Published: August 2024

Chaotic synchronization is crucial in the field of secure communication, and fixed-time synchronization has realistic application prospects and demands. Aiming at the traditional sliding mode synchronization control method with chattering problem, based on the Lyapunov stability theory and incorporating the continuous time fixed time stability theorem, this paper proposed a new fixed-time sliding mode control scheme for synchronization of chaotic systems. The traditional finite-time sliding mode synchronization is compared with the proposed fixed-time sliding mode synchronization scheme and the results are discussed. The efficacy of the controller is validated using MATLAB simulations, which eliminates the chatter problem in the traditional sliding mode synchronization scheme and has the advantage of short synchronization time. In addition, the parameters of the controller can be set flexibly, which is an advantage of the fixed-time synchronous control scheme.
Analysis of structural, dielectric, magnetic and impedance spectroscopy of ZnO/CuFe2O4 nanocomposites
Authors: Ali Kashif , Ilyas Asif
Published: August 2024

The nanocomposites of ZnO/CuFe
2
O
4; abbreviated as (ZnO)

x

/(COF)
1-x
(x; 10 ∼ 50 wt%) were prepared by powder mixing method. The x-ray diffraction pattern revealed the formation of nanocomposites (NCs) with inverse spinel structure of COF and hexagonal wurtzite structure of ZnO. The scanning electron microscope analysis depicts the nano-plates like morphology, non-homogenous mixing and agglomeration of particles. The dielectric properties and impedance spectroscopy of NCPs were measured by LCR meter in the frequency range of 1 kHz to 2 MHz. There is decrease in the real and imaginary parts of dielectric constant (ε′ and ε″) were observed with frequency, which is explained by Maxwell–Wagner’s polarization mechanism. The real and imaginary parts of impedance (Z′ and Z″) also show decreasing trend with frequency owing to increase in hopping of charge carriers that result in enhancement of a.c. conductivity (σ

a.c
). The impedance spectroscopy shows a semicircular arc at higher frequency which is attributed to the conduction from grains. Finally, the vibrating sample magnetometer result showed the change in the magnetic nature of NCPs; as saturation magnetization (M

s
) and coercivity (H

c
) decreases substantially with incorporation of non-magnetic ZnO weight fractions.
Insights into electron and phonon topology: multi-fold fermions and Dirac nodal-line net bosons in SiX2 (X=P and As)
Authors: T Aiswarya , Singh Jaspreet , Kanchana V , Vaitheeswaran G
Published: August 2024

There has been a notable increase in enthusiasm for delving into new (quasi) particles within the domains of condensed matter and materials. Particularly, a distinctive excitement has arisen over a recently theorized exotic excitation found in a three-dimensional material, showcasing linear dispersion and the possibility of multi-fold degeneracy. In this article, we embark on an extensive investigation into the multi-fold degenerate exotic fermions beyond Dirac and Weyl in the pyrite-structured SiX2 compounds (with X as P and As). We delve into the topological attributes of band-touching nodes in fermions, featuring four- and six-fold degeneracy positioned at the Γ and R points in the first Brillouin zone, analyzing them through symmetry analysis. Regarding bosons, employing symmetry analysis, this study identifies distinctive properties where three-nodal surfaces (NSs) and phononic Dirac nodal-line (DNL) nets coexist. These phononic DNL nets comprise three phononic DNLs that share a common nodal point in momentum space, positioned at the intersection of two out of the three k

i
planes (i = x, y, z). The presence of observable phononic surface states in these materials may facilitate their experimental detection, suggesting these materials’ potential as prime candidates for realizing such phononic states in solid-state materials. Our investigation highlights the pyrite-structured SiX2 as a promising platform for studying multi-fold fermions and delving into their potential applications.
Enhanced gamma-ray shielding capabilities of Bi-Se-Ge chalcogenide glasses: analytical and simulation insights
Authors: Issa Shams A. M. , Khandaker Mayeen Uddin , Badawi Ali , Zakaly Hesham M H
Published: August 2024

This study investigates the gamma-ray shielding properties of Bi-Se-Ge chalcogenide glasses using advanced computational tools. The Phy-X/PSD and FLUKA programs were utilized to determine critical shielding parameters such as linear attenuation coefficient (

G

LAC

), mass attenuation coefficient (

G

MAC

), half-value layer (

G

HVL

), mean free path (

G

MFP

), and effective atomic number (

Z

eff

). Our findings reveal that these glasses exhibit superior shielding capabilities compared to traditional materials. For instance, the

G

MAC

values for the glasses ranged from 101.472 cm2/g to 177.475 cm2/g at a photon energy of 0.015 MeV. Additionally, the

G

HVL

values decreased significantly with increasing Bi content, from 4.082 cm to 3.104 cm at an energy level of 15 MeV. The effective atomic number (

Z

eff

) also increased from 36.12 to 53.23 with higher Bi concentrations. These insights, derived from precise computational analysis, highlight the potential of Bi-Se-Ge glasses for applications in radiation protection. The discussion also examines the impact of substituting Bi atoms with Se on the shielding capabilities of the original Bi-Se-Ge glass.

Future work will focus on experimental validation of these results to further substantiate our findings.
Retardation theory of eleven galaxies
Authors: Wagman Michal , Horwitz Lawrence Paul , Yahalom Asher
Published: August 2024

The missing mass problem has been with us since the 1970s, as Newtonian gravity using baryonic mass cannot account for various observations. We investigate the viability of retardation theory, an alternative to the Dark Matter paradigm (DM) which does not seek to modify the General Principal of Relativity but to improve solutions within it by exploring its weak field approximation to solve the said problem in a galactic context. This approach have yielded satisfactory results, with respect to galactic rotation curves, the Tully-Fisher relation and missing mass derived from gravitational lensing. Recently it was able to introduce a necessary correction to the virial theorem explaining mass excess in clusters of galaxies. The current work presents eleven rotation curves calculated using Retardation Theory. The calculated rotation curves are compared with observed rotation curves. Values for the change in mass flux to mass ratio are extracted from the fitting process as a free fitting parameter. Those quantities are interpreted here and in previous works using galactic processes. Retardation Theory was able to successfully reproduce rotation curves and a preliminary correlation with star birthrate index is seen, suggesting a possible link between galactic winds and observed rotation curves. Retardation Theory shows promising results within current observations. More research is needed to elucidate the suggested mechanism and the processes which contribute to it. Galactic mass outflows carried by galactic winds may affect rotation curves.
Depinning of domain walls in a notched ferromagnetic nanostrip: role of inertial and nonlinear damping effects
Authors: Dolui Sarabindu , Maity Sumit , Dwivedi Sharad , Consolo Giancarlo
Published: August 2024

In this work, we investigate theoretically the static and kinetic depinning field of a domain wall in a notched magnetic nanostrip under the generalized framework of the Landau–Lifshitz-Gilbert equation, which combines inertial and nonlinear viscous-dry friction damping effects. We assume a head-to-head transverse domain wall configuration and analyzed its motion subject to a time-varying external magnetic field. To deduce the equation ruling the spatio-temporal evoution of the magnetic domain wall, we adopt the Schryer and Walker trial function approach. The results show that static and kinetic depinning fields increase as the dry friction dissipation increases. Moreover, viscous dissipation exhibits a weak dependence on the kinetic depinning field and saturated domain wall velocity, while inertial damping due to the relaxation time of angular momentum significantly impacts the kinetic depinning field, depinning time, and breakdown velocity. Our numerical results are in good qualitative agreement with the recent observations reported in the literature.
Phase sensitivity of entanglement in the Quantum Phase Estimation algorithm
Authors: Amouzou Grâce , Atchonouglo Kossi , Holweck Frédéric
Published: August 2024

We study entanglement in the steps before Quantum Fourier Transform (pre-QFT) part of the Quantum Phase Estimation and the Quantum Counting algorithms (QPEA—QCA) with the use of three entanglement detection tools. In particular we focus on the sensitivity of entanglement to the input value (the phase ϕ and the ratio of marked elements

M

N

) in some basic cases. One starts from numerical observations and deduce some general results in particular regarding the classes of entanglement. More precisely, when the second register of both algorithms (i.e. the register on which a specific unitary operator act, see section 2) is initialized in the non-entangled superposition of two (separable) eigenvectors, one proves that the QPEA and QCA curves of entanglement evolution are the same up to a scalar multiplication of the parameter ϕ. One demonstrates that a local minimum is obtained and corresponds to an EPR (Einstein-Podolsky-Rosen) state and finally one proves that, up to Stochastic Local Operation and Classical Communication (SLOCC), all states, except for a few values of ϕ, are equivalent to the product of a separable state and a generalized GHZ (Greenberger-Horen-Zeilinger) state , i.e.

GHZ

n
+
1

=

1

2

(

00
...
0

+

11
...
1

)

.
Anomalous hot electron generation from two-plasmon decay instability driven by broadband laser pulses with intensity modulations
Authors: Yao C. , Li J. , Hao L. , Yan R. , Wang C. , Lei A. , Ding Y-K. , Zheng J.
Published: August 2024

We investigate the hot electrons generated from two-plasmon decay (TPD) instability driven by laser pulses with intensity modulated by a frequency Δω

m
using theoretical and numerical approaches. Our primary focus lies on scenarios where Δω

m
is on the same order of the TPD growth rate γ
0 (

Δ

ω
m

∼

γ
0

), corresponding to moderate laser frequency bandwidths for TPD mitigation. With Δω

m
conveniently modeled by a basic two-color scheme of the laser wave fields in fully-kinetic particle-in-cell simulations, we demonstrate that the energies of TPD modes and hot electrons exhibit intermittent evolution at the frequency Δω

m
, particularly when

Δ

ω
m

∼

γ
0

. With the dynamic TPD behavior, the overall ratio of hot electron energy to the incident laser energy,

f

hot

, changes significantly with Δω

m
. While

f

hot

drops notably with increasing Δω

m
at large Δω

m
limit as expected, it goes anomalously beyond the hot electron energy ratio for a single-frequency incident laser pulse with the same average intensity when Δω

m
falls below a specific threshold frequency Δω

c
. This anomaly arises from the pronounced sensitivity of

f

hot

to variations in laser intensity. We find this threshold frequency Δω

c
primarily depends on γ
0 and the collisional damping rate of plasma waves, with relatively lower sensitivity to the density scale length. We develop a scaling model characterizing the relation of Δω

c
and laser plasma conditions, enabling the potential extention of our findings to more complex and realistic scenarios.
Asymptotic behaviour of a phase field system derived from a generalization of Maxwell–Cattaneo’s law with a singular potential
Authors: Landry Doumbé Bangola Brice , Ali Ipopa Mohamed , Andami Ovono Armel
Published: August 2024

In this paper, we study the asymptotic behaviour of a Caginalp-type phase field system derived from a heat conduction law which is a generalization of the Maxwell–Cattanéo law and whose potential is singular. This type of law has the advantage of correcting the paradox of heat conduction that appears when the Fourier law is considered. The potential considered is typically logarithmic. Using such a potential makes the model much more relevant from a physical point of view. However, from a theoretical point of view, it is essential to obtain the strict separation property of the phase field in order to give sense of the equations. We first prove the existence and uniqueness of the solution thanks to the separation property. We also address the question of the dissipativity of the system. Finally, we obtain the existence of the global attractor.
Combining Nitellopsis obtusa autofluorescence intensity and F680/F750 ratio to discriminate responses to environmental stressors
Authors: Navickaite Ausrine , Pupkis Vilmantas , Kalnaityte-Vengeliene Agne , Lapeikaite Indre , Kisnieriene Vilma , Bagdonas Saulius
Published: August 2024

Detection of autofluorescence parameters is a useful approach to gain insight into the physiological state of plants and algae, but the effect of reabsorption hinders unambiguous interpretation of in vivo data. The exceptional morphological features of Nitellopsis obtusa made it possible to measure autofluorescence spectra along single internodal cells and estimate relative changes in autofluorescence intensity in selected spectral regions at room temperatures, avoiding the problems associated with thick or optically dense samples. The response of algal cells to controlled white light and DCMU herbicide was analyzed by monitoring changes in peak FL intensity at 680 nm and in F680/F750 ratio. Determining the association between the selected spectral FL parameters revealed an exponential relationship, which provides a quantitative description of photoinduced changes. The ability to discern the effect of DCMU not only in the autofluorescence spectra of dark-adapted cells, but also in the case of light-adapted cells, and even after certain doses of excess light, suggests that the proposed autofluorescence analysis of N. obtusa may be useful for detecting external stressors in the field.
A leaf sequencing algorithm for an orthogonal dual-layer multileaf collimator
Authors: Cui Weijie , Dai Jianrong
Published: August 2024

Purpose. Dual layer MLC (DMLC) has have been adopted in several commercial products and one major challenge in DMLC usage is leaf sequencing for intensity-modulated radiation therapy (IMRT). In this study we developed a leaf sequencing algorithm for IMRT with an orthogonal DMLC. Methods and Materials. This new algorithm is inspired by the algorithm proposed by Dai and Zhu for IMRT with single layer MLC (SMLC). It iterately determines a delivery segment intensity and corresponding segment shape for a given fluence matrix and leaves residual fluence matrix to following iterations. The segment intensity is determined according to complexities of residual fluence matrix when segment intensity varies from one to highest level in the matrix. The segment intensity and corresponding segment shape that result least complexity was selected. Although the algorithm framework is similar to Dai and Zhu’s algorithm, this new algorithm develops complexity algorithms along with rules for determining segment leaf settings when delivered with orthogonal DMLC. This algorithm has been evaluated with 9 groups of randomly generated fluence matrices with various dimensions and intensity levels. Sixteen fluence matrices generated in Pinnacle system for two clinical IMRT examples were also used for evaluation. Statistical information of leaf sequences generated with this algorithm for both the random and clinical matrices were compared to the results of two typical algorithms for SMLC: that proposed by Dai and Zhu and that proposed by Bortfled. Results. Compared to the SMLC delivery sequences generated with Dai and Zhu’s algorithm, the proposed algorithm for orthogonal DMLC delivery reduces the average number of segments by 27.7% ∼ 41.8% for 9 groups of randomly generated fluence matrices and 10.5% ∼ 41.7% for clinical ones. When comparing MU efficiency between different algorithms, it is observed that the proposed algorithm performs better than the optimal efficiency of SMLC delivery when dealing with simple fluence matrices, but slightly worse when handling complex ones. Conclusion. This new algorithm generates leaf sequences for orthogonal DMLC delivery with high delivery efficiency in terms of number of leaf segments. This algorithm has potential to work well with orthogonal DMLC for improving efficiency or quality of IMRT.
Urban sprawl and thermal response in the Guangdong-Hong Kong-Macao Greater Bay Area, 2000–2020
Authors: Yuan Hao , Chen Yonglin , Zhang Yunping , Ming Lei , Xie Yuntao
Published: August 2024

The urban heat island (UHI) environment is closely related to the daily life of residents, and the impact of UHI is further expanding in the era of rapid urbanization, which is particularly obvious in the Beijing-Tianjin-Hebei urban agglomeration and Guangdong-Hong Kong-Macao Greater Bay Area (GBA). To explore the connection between UHI and urban expansion, this study takes GBA as the study area, based on Google Earth Engine platform and Landsat satellite data. The urban-rural temperature difference method was used to analyze the heat island zoning in the GBA from 2000 to 2020, and the direction and type of urban expansion in the GBA were investigated by standard deviation ellipse and LEI, to explore the link between the type of urban expansion and the heat island region through geospatial analysis methods. The results of the study show that: (1) The proportion of the area of strong and extreme heat islands in the GBA was 37.64% in 2000; 38.61% in 2005; 47.07% in 2010; 55.76% in 2015; and finally 59.69% in 2020. The proportion of the area of heat island regions in the period from 2000 to 2020 showed an overall increasing trend, with the largest increase in heat island regions in the period from 2015 to 2020. (2) The intensity of urban expansion in the GBA is 32% in both 2000–2005 and 2005–2010, which is significantly higher than the 9% in 2010–2015, and then increases to 24 per cent in 2015–2020. The speed of movement of urban centroids decreases in 2000–2015 and increases in 2015–2020. The direction of urban expansion in the first 5 years is dominated by the northeast, and the direction of urban expansion in the latter 15 years is generally dominated by the southwest, and the type of urban expansion is dominated by the fringe type, with the enclave type of expansion accounting for a smaller proportion. (3) Pearson correlation analysis further confirms that there is a significant positive correlation between urban sprawl and the urban heat island effect, with a correlation coefficient of 0.78 and a p-value of 0.041. There is a high degree of spatial consistency between the distribution of built-up urban areas and the distribution of heat island areas in GBA, and the direction of the evolution of the urban heat island areas is the same as the direction of the evolution of the built-up urban areas in general, and the thermal response of the marginal expansion to the ground surface temperature is stronger than that of enclave expansion. The thermal response to the surface temperature is stronger than that of the enclave type of expansion.
Research on hammering characteristics of hammer mill based on discrete element method
Authors: Li Tianqi , Shi Guangfeng , Zhang Qing
Published: August 2024

In hammer mill crushing, the speed change of the rotor hammer head will have an effect on the efficiency of crushing, and so on. This paper takes the hammer mill rotor as the research object and carries out a simulation study, establishes the material particle crushing model, and verifies the validity of the model. The discrete element method (DEM) is used to simulate the movement of the material inside the hammer mill after crushing, revealing that the working principle of the hammer mill is based on the form of particle movement, and to study the law of the particle collision fracture bond energy, compressive stress and particle collision impact energy of the hammer mill. Through comparison, the final working condition of the hammer mill is that at the rotor speed of 1600 r min−1, the working efficiency of the whole equipment is the highest.
Investigations on the influence of hot rolling on the creep characteristics of additively manufactured Mg-5Ag alloy
Authors: Karthik S Hare , Jaganath D , Balan K Siva , Ramasubramanian M , R Vaira Vignesh , M Govindaraju , Suganya Priyadharshini G , Baghad Abd
Published: August 2024

The requirement for lightweight materials that can survive increasingly severe conditions for aerospace components has fueled the research on magnesium alloys. The current work investigates the influence of hot rolling on the creep characteristics of the Mg-5Ag alloy that is fabricated through a selective laser melting process. The creep properties of parent material (PM) and hot-rolled specimens (HRA) are determined by indentation creep tests at 250 °C, 275 °C, and 300 °C. The microstructural evolution, phase transformation kinetics, and texture evolution were deduced using instrumental analysis, including SEM, EBSD, TEM, and XRD. The specimen PM features α-Mg grains with intermetallic Mg-Ag particles along grain boundaries and random grain orientations with low-angle boundaries. However, specimen HRA has a more fraction of Mg-Ag precipitates, a dominant (0001) grain orientation, and higher peak intensity from the (002) plane. The HRA specimen also demonstrates higher apparent activation energies, attributed to microstructural changes from hot rolling. The results show that the creep resistance of the hot rolled Mg-5Ag alloy is superior to as-fabricated Mg-5Ag alloy based on the creep velocity, stress exponent, and apparent activation energy.
Au – MoS2 nanoflowers sensors on interdigitated electrode for monitoring human respiration
Authors: Pujari Sakshi , Tripathi Himadri , Dobhal Anshuman , Rawat S , Dangwal Shivani , Bala Shashi , Rani Chanchal , Dwivedi C , Kumar Rajesh , Sharma M , Sharma Himani
Published: August 2024

Respiratory humidity sensors are essential for monitoring breath conditions in a variety of applications such as respiratory disease diagnosis, sleep apnea screening, and personalized medicine. With the increasing prevalence of respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and sleep apnea, they have become essential tools for healthcare professionals, researchers and individuals. However, existing humidity sensors often suffer from poor sensitivity, slow response, and limited flexibility. In this paper, we report a novel Au – MoS2 respiratory humidity sensor that exhibits high resistivity, fast response, and excellent flexibility. The sensor is fabricated by drop casting a thin layer of Au decorated MoS2 on copper interdigitated electrodes (fabricated using copper clad PCB). The increase in the intensity of the peak was observed in Au – MoS2 hybrids in comparison to MoS2 analyzed using micro–Raman Spectroscopy. Using scanning electron microscopy (SEM), the morphology of MoS2 was observed, confirming its flower like structure. The Au nanoparticles were detected on the edges of MoS2, confirmed by transmission electron microscope (TEM).The interfacial electronic interaction suggests that there is the formation of Schottky barrier between Au and MoS2 as confirmed by X–Ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). The improved electronic interaction results in better sensing properties. The high dielectric constant and excellent surface-to-volume ratio of the MoS2 layer make it extremely sensitive to humidity; the Au nanoparticles offer good electrical conductivity and mechanical flexibility in its place. The study tested a respiratory sensor in a simulated environment, finding it more responsive to breathing and quick to return to rest. This suggests potential for the Au-MoS2 sensor in tracking breath states due to its sensitivity and adaptability, promising applications across various fields.
A comparative study of broadband PbS quantum dots/graphene photodetectors with monolayer and bilayer graphene
Authors: Olson Austin , Chambers Dakeya , Gotfredson Sarah , Shultz Andrew , Liu Bo , Gong Maogang , Wu Judy Z
Published: August 2024

Colloidal quantum dots (QDs)/graphene nanohybrids provide a unique platform to design photodetectors of high performance. These photodetectors are quantum sensors due to the strong quantum confinement in QDs for spectral tunability, and in graphene for high charge mobility. Quantitatively, the high carrier mobility of graphene plays a critical role to enable high photoconductive gain and understanding its impact on the photodetector performance is imperative. Herein, we report a comparative study of PbS QDs/graphene nanohybrids with monolayer and bilayer graphene for broadband photodetection ranging from ultraviolet, visible, near-infrared to short-wave infrared spectra (wavelength: 400 nm–1750 nm) to determine if a specific advantage exists for one over the other. This study has revealed that both the monolayer and bilayer graphene grown in chemical vapor deposition can provide a highly efficient charge transfer channel for photo-generated carriers for high broadband photoresponse.
Analysis of the Taylor-Hood surface finite element method for the surface Stokes equation
Authors: Reusken Arnold
Published: August 2024

We consider the surface Stokes equation on a smooth closed hypersurface in

R

3

\mathbb {R}^3

. For discretization of this problem a generalization of the surface finite element method (SFEM) of Dziuk-Elliott combined with a Hood-Taylor pair of finite element spaces has been used in the literature. We call this method Hood-Taylor-SFEM. This method uses a penalty technique to weakly satisfy the tangentiality constraint. In this paper we present a discretization error analysis of this method resulting in optimal discretization error bounds in an energy norm. We also address linear algebra aspects related to (pre)conditioning of the system matrix.
On certain equivalences of metric spaces
Authors: Pernecká Eva , Spěvák Jan
Published: August 2024

The normed spaces of molecules constructed by Arens and Eells allow us to define two natural equivalence relations on the class of complete metric spaces. We say that two complete metric spaces

M
M

and

N
N

are

M

o
l

\mathcal {M}\hspace {-1.5pt}\mathcal {ol}

-equivalent if their normed spaces of molecules are isomorphic and we say that they are

F

\mathcal {F}

-equivalent if the corresponding completions – the Lipschitz-free Banach spaces

F

(
M
)

\mathcal {F}(M)

and

F

(
N
)

\mathcal {F}(N)

– are isomorphic.

In this note, we compare these and some other relevant equivalences of metric spaces. Clearly,

M

o
l

\mathcal {M}\hspace {-1.5pt}\mathcal {ol}

-equivalent spaces are

F

\mathcal {F}

-equivalent. Our main result states that

M

o
l

\mathcal {M}\hspace {-1.5pt}\mathcal {ol}

-equivalent spaces must have the same covering dimension. In combination with the work of Godard, this implies that

M

o
l

\mathcal {M}\hspace {-1.5pt}\mathcal {ol}

-equivalence is indeed strictly stronger than

F

\mathcal {F}

-equivalence. However,

M

o
l

\mathcal {M}\hspace {-1.5pt}\mathcal {ol}

-equivalent spaces need not be homeomorphic, as we demonstrate through a general construction. We also observe that

M

o
l

\mathcal {M}\hspace {-1.5pt}\mathcal {ol}

-equivalence does not preserve the Assouad dimension.

We introduce a natural notion of a free basis to simplify the notation.
Semialgebraicity of the convergence domain of an algebraic power series
Authors: Kaiser Tobias
Published: August 2024

Given a power series in finitely many variables that is algebraic over the corresponding polynomial ring over a subfield of the reals, we show that its convergence domain is semialgebraic over the real closure of the subfield. This gives in particular that the convergence radius of a univariate Puiseux series that is algebraic in the above sense belongs to the real closure or is infinity.
Notes on a conjecture by Paszkiewicz on an ordered product of positive contractions
Authors: Ando Hiroshi
Published: August 2024

Paszkiewicz’s conjecture asserts that given a decreasing sequence

T
1

≥

T
2

≥
…

T_1\ge T_2\ge \dots

of positive contractions on a separable infinite-dimensional Hilbert space

H
H

, the product

S
n

=

T
n

T

n
−
1

⋯

T
1

S_n=T_nT_{n-1}\cdots T_1

converges in the strong operator topology. In these notes, we give an equivalent, more precise formulation of his conjecture. Moreover, we show that the conjecture is true for the following two cases: (1)

1
1

is not in the essential spectrum of

T
n

T_n

for some

n
∈

N

n\in \mathbb {N}

. (2) The von Neumann algebra generated by

{

T
n

∣
n
∈

N

}

\{T_n\mid n\in \mathbb {N}\}

admits a faithful normal tracial state. We also remark that the analogous conjecture for the weak convergence is true.
Lusztig correspondence and the finite Gan-Gross-Prasad problem
Authors: Wang Zhicheng
Published: August 2024

The Gan-Gross-Prasad problem is to describe the restriction of representations of a classical group

G
G

to smaller groups

H
H

of the same kind. In previous work by Liu and Wang [Trans. Amer. Math. Soc. 373 (2020), pp. 4223–4253; Manuscripta Math. 165 (2021), pp. 159–189; Math. Z. 297 (2021), pp. 997–1021] and Wang [Adv. Math. 393 (2021), p. 72], we study the Gan-Gross-Prasad problem for unipotent representations of finite classical groups. In this paper, we solved the Gan-Gross-Prasad problem over finite fields completely. The main tools used are the Lusztig correspondence and a formula of Reeder [J. Amer. Math. Soc. 20 (2007), pp. 573–602] for the pairings of Deligne-Lusztig characters. We give a reduction decomposition of Reeder’s formula and reduce the Gan-Gross-Prasad problem for arbitrary representations to the unipotent representations by Lusztig correspondence.
On well-posedness of 𝛼-SQG equations in the half-plane
Authors: Jeong In-Jee , Kim Junha , Yao Yao
Published: August 2024

We investigate the well-posedness of

α
\alpha

-surface quasi-geostrophic (

α
\alpha

-SQG) equations in the half-plane, where

α
=
0

\alpha =0

and

α
=
1

\alpha =1

correspond to the 2D Euler and SQG equations respectively. For

0
>
α
≤
1

/

2

0>\alpha \le 1/2

, we prove local well-posedness in certain weighted anisotropic Hölder spaces. We also show that such a well-posedness result is sharp: for any

0
>
α
≤
1

0>\alpha \le 1

, we prove nonexistence of Hölder regular solutions (with the Hölder regularity depending on

α
\alpha

) for initial data smooth up to the boundary.