bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of peptide hydrophilicity on membrane curvature and permeation
Authors: Mathath Anjana V. , Chakraborty Debashree 
Published: October 2024

Using a well-developed reaction coordinate in umbrella sampling, we studied the single peptide permeation through a model cancerous cell membrane, varying the hydrophilicity and the charge of the peptides. Two peptides, melittin and pHD108, were studied. The permeation mechanism differs from a barrel-stave-like mechanism to toroidal pore and vesicle formation based on the number and the placement of the hydrophilic amino acids in the peptide. Membrane curvature changes dynamically as the permeation process occurs. In the case of vesicles, the peptide traverses along a smooth, homogenous pathway, whereas a rugged, steep pathway was found when lipid molecules did not line up along the wall of the membrane (barrel-stave-like mechanism). A mechanism similar to a toroidal pore consists of multiple minima. Higher free energy was found for the permeating terminal containing charged amino acid residues. Vesicle formation was found for pHD108 peptide N-terminal with a maximum membrane thinning effect of 54.4% with free energy cost of 8.20 ± 0.10 kcal mol−1 and pore radius of 2.33 ± 0.07 nm. Insights gained from this study can help to build synthetic peptides for drug delivery.
A multi-modal high pressure and high temperature reaction cell for combined x-ray spectroscopy, scattering, and imaging
Authors: Kathyola Thokozile A. , Keylock Stephen J. , Ignatyev Konstantin , Filik Jacob , Drnec Jakub , Webb Paul B. , Kroner Anna B. , Diaz-Moreno Sofia 
Published: October 2024

A free-standing and compact reaction cell for combined in situ/operando x-ray spectroscopy, scattering, and imaging measurements at high pressures and high temperatures is described. The cell permits measurements under realistic operating conditions (up to 50 bar and 1000 °C), under static and flow conditions (up to 100 ml/min), over a wide range of hard x-ray energies, variable detection modes (transmission, fluorescence, and scattering), and at all angles of rotation. An operando XAS, x-ray fluorescence, x-ray computed tomography, and x-ray diffraction computed tomography case study on the reduction of a heterogeneous catalyst is presented to illustrate the performance of the reaction cell.
Predicting kinetics of spin-dependent reactions in an external magnetic field with nonadiabatic statistical theory
Authors: Rooein Mitra , Varganov Sergey A. 
Published: October 2024

We introduce a theoretical framework to study the kinetics of the chemical reactions involving transitions between electronic states with different spin quantum numbers in an external magnetic field. The new equations for calculating transition probabilities and rate constants are used to generalize the nonadiabatic statistical theory, which now accounts for both the spin–orbit and Zeeman couplings between electronic states. Focusing on the singlet–triplet transitions, we define two dimensionless parameters to characterize (1) the magnetic field strength relative to the strength of spin–orbit coupling and (2) the relative magnitudes of the spin–orbit coupling matrix elements that couple the singlet state to different components of the triplet state. Based on the values of these dimensionless parameters, we define distinct coupling regimes and propose specific approaches to calculating the transition probabilities and rate constants in these regimes. We apply the introduced theoretical framework to study the effect of an external magnetic field on the kinetics of spin-forbidden isomerization of the Ni(dpp)Cl2 [dpp = 1,3-bis(diphenylphosphino)propane] complex in the strong and weak field regimes. Our calculations predict that in a magnetic field of 50 T, the isomerization rate constant increases by about 10%. We hope this work will facilitate renewed efforts in controlling spin-dependent chemical reactions with an external magnetic field.
Systematic Uncertainties from Gribov Copies in Lattice Calculation of Parton Distributions in the Coulomb Gauge
Authors: Gao Xiang , He Jinchen , Zhang Rui , Zhao Yong 
Published: October 2024

Abstract
Recently, a new method has been proposed to compute parton distributions using boosted correlators fixed in the Coulomb gauge (CG) within the framework of large-momentum effective theory. This approach, which does not involve Wilson lines, could greatly improve the efficiency and precision of lattice quantum chromodynamics calculations. However, concerns remain regarding whether systematic uncertainties from Gribov copies, which correspond to ambiguities in lattice gauge-fixing, are adequately controlled. This work assesses the effects of Gribov copies on Coulomb-gauge-fixed quark correlators. We utilize different strategies for Coulomb-gauge fixing, selecting two different groups of Gribov copies based on lattice gauge configurations. We examine the differences in the resulting spatial quark correlators in both vacuum and pion states. Our findings indicate that the statistical errors of the matrix elements from both Gribov copies, regardless of the correlation range, decrease proportionally to the square root of the number of gauge configurations. The difference between the strategies does not show statistical significance compared to the gauge noise, demonstrating that the effect of the Gribov copies can be neglected in practical lattice calculations of quark parton distributions.
On the convergence of cosmographic expansions in Lemaître–Tolman–Bondi models
Authors: Modan Asha B , Koksbang S M 
Published: October 2024

AbstractWe study cosmographic expansions of the luminosity distance for a variety of Lemaître–Tolman–Bondi (LTB) models which we specify inspired by local large-scale structures of the Universe. We consider cosmographic expansions valid for general spacetimes and compare to the Friedmann–Lemaître–Robertson–Walker (FLRW) limit of the expansions as well as to its naive isotropic extrapolation to an inhomogeneous Universe. The FLRW expansions are often poor near the observer but become better at higher redshifts, where the light rays have reached the FLRW background. In line with this we find that the effective Hubble, deceleration and jerk parameters of the general cosmographic expansion are often very different from the global ΛCDM values, with deviations up to several orders of magnitude. By comparing with the naive isotropic extrapolation of the FLRW expansion, we assess that these large deviations are mainly due to gradients of the shear. Very close to the observer, the general cosmographic expansion is always best and becomes more precise when more expansion terms are included. However, we find that the convergence radius of the general cosmographic expansion is small for all studied models and observers and the general cosmographic expansion becomes poor for most of the studied observers already before a single LTB structure has been traversed. The small radius of convergence of the general cosmographic expansion has also been indicated by earlier work and may need careful attention before we can safely apply the general cosmographic expansion to real data.
Back-decay of the muonic molecular ion

(
α
μ
t

)

01

2
+

resonantly formed in

(
t
μ
)

1
s

+
4

HeH

+

collision
Authors: Czapliński Wilhelm 
Published: October 2024

Abstract
Resonant formation of the muonic molecular ion

(
α
μ
t

)

01

2
+

in the collision of the muonic tritium atom with the helium hydride ion,

(
t
μ
)

1
s

+
4

HeH

+

→

[

(
α
μ
t
)

01

2
+

,
p
,
e
e
]

+

, is proposed. The

(
α
μ
t
)

01

2
+

ion is formed in the rotational-vibrational state (0,1) as one of the two nuclei of the final complex. Back-decay process

[

(
α
μ
t
)

01

2
+

,

p
,
e
e
]

K
n

+

→

(
t
μ
)

1
s

+
4

HeH

K
′

n
′

+

, where K and n (

K
′

and

n
′

) is the rotational and vibrational quantum number, respectively, is considered in detail and the corresponding decay widths for all possible rotational-vibrational

(
K
,
n
)
→
(

K
′

,

n
′

)

transitions are calculated. Numerous inelastic decay channels of

(
α
μ
t

)

01

2
+

are also presented and discussed. The possible fast resonant formation of the

(
α
μ
t
)

01

2
+

ion may provide an interesting tool for experimental studies of

t

(
α
,
γ
)

7

Li

nuclear fusion, which is one of the most important reactions in Big-Bang nucleosynthesis models. Studying this reaction may prove important for solving the lithium problem.
Geometry, anomaly, topology, and transport in Weyl fermions
Authors: Ahmad Azaz , K Gautham Varma , Sharma Gargee 
Published: October 2024

Abstract
Weyl fermions are one of the simplest objects that link ideas in geometry and topology to high-energy physics and condensed matter physics. Although the existence of Weyl fermions as elementary particles remains dubious, there is mounting evidence of their existence as quasiparticles in certain condensed matter systems. Such systems are termed Weyl semimetals (WSMs). Needless to say, WSMs have emerged as a fascinating class of materials with unique electronic properties, offering a rich playground for both fundamental research and potential technological applications. This review examines recent advancements in understanding electron transport in WSMs. We begin with a pedagogical introduction to the geometric and topological concepts critical to understanding quantum transport in Weyl fermions. We then explore chiral anomaly, a defining feature of WSMs, and its impact on transport phenomena such as longitudinal magnetoconductance and planar Hall effect. The Maxwell-Boltzmann transport theory extended beyond the standard relaxation-time approximation is then discussed in the context of Weyl fermions, which is used to evaluate various transport properties. Attention is also given to the effects of strain-induced gauge fields and external magnetic fields in both time-reversal broken and inversion asymmetric inhomogeneous WSMs. The review synthesizes theoretical insights, experimental observations, and numerical simulations to provide a comprehensive understanding of the complex transport behaviors in WSMs, aiming to bridge the gap between theoretical predictions and experimental verification.
Online classroom student engagement analysis based on facial expression recognition using enhanced YOLOv5 for mitigating cyberbullying
Authors: Wang Shuai , Chen Miaoxia , Ratnavelu K , Bin Shibghatullah Abdul Samad , Keoy Kay Hooi 
Published: October 2024

Abstract
The rapid expansion of online education has heightened concerns about cyberbullying in virtual classrooms. This paper presents a comprehensive approach for detecting cyberbullying by analyzing students’ engagement and emotional responses in online classrooms. Due to the influence of camera resolution and surrounding light in online classrooms, students’ facial expressions are often blurry, and the changes in facial features may not be significant. Moreover, most current recognition algorithms utilize larger models, which may not be suitable for real-time detection in online environments. To address these challenges, this study introduces a student facial expression recognition (SFER) method based on an enhanced YOLOv5 (you only look once version 5) model, termed SFER-YOLOv5. Firstly, the improved soft-non-maximum suppression (NMS) is employed to replace the original NMS, effectively enhancing training efficiency. Then, the coordinate attention module is incorporated into the backbone network to improve detection accuracy, particularly in classroom settings with multiple students or when students are at a considerable distance from the camera. Next, the efficient intersection over union (EIoU) loss function is utilized. EIoU calculates width and height losses separately based on complete-IoU, replacing the aspect ratio. Finally, focal loss is introduced to address sample imbalance issues. The comparative results show that SFER-YOLOv5 achieves an mAP@0.5 of 78.4% on the facial expression recognition-2013 dataset, 98.1% on the CK+ dataset, and 88.9% on our self-constructed dataset student facial expressions in classroom (SFEC). These results underscore the effectiveness of SFER-YOLOv5 in enhancing the accuracy of SFER. The proposed method detects reduced engagement, offering a preventive strategy for mitigating cyberbullying in virtual learning environments.
Elucidating a proper framework for the determination of threading dislocation densities in semiconductor films: a comprehensive study based on Ge/Si(001)
Authors: Xu Chi , Wu Zhengjie , Li Yue , Wang Xiaoyu , Chang Xiyan , Xie Changjiang , Wang Caile , Chen Chen , Wang Yixin , Cong Hui , Xue Chunlai 
Published: October 2024

Abstract
Methods of deducing threading dislocation densities (TDDs) from x-ray diffraction (XRD) peak widths have been reevaluated based on crystallography theories. Moreover, Ge/Si heteroepitaxial structures were taken as model materials for investigation. The procedure is tailored in accordance with the specific designs of modern XRD systems to minimize instrumental interference, whereas practical characteristics of heteroepitaxial films are also considered to avoid intrinsic errors. TDDs of samples grown with different epitaxy methods were investigated using the newly implemented XRD method and etch pit density (EPD) method, and satisfactory agreement has been achieved among three independently calculated sets of TDD results: two from XRD and one from EPD. These values were further corroborated by cross-sectional transmission electron microscopy analysis. Key considerations that are of scientific and technical importance in TDD studies are also discussed in detail. The present work provides not only the most up-to-date elucidation on obtaining TDD values in semiconductor epitaxial films, but also insights into the long-existing ambiguity in TDD calculation methods, which will be helpful for the future studies of defect density characterizations in various material systems.
Enhanced photocatalytic degradation of organic pollutants by randomly oriented 2D SnS2 nanostructures
Authors: Kumari Ritu , Kumar Rakesh 
Published: October 2024

Abstract
In this study, we present a bottom-up solvothermal technique using tin tetrachloride pentahydrate (SnCl4.5H2O) and thioacetamide as precursors to synthesize SnS2 nanostructures. Different solvents including isopropyl alcohol, ethanol (EN), and ethylene glycol were used in the reaction to enhance the photodegradation efficiency of organic pollutants, Methylene Blue (MB), and Tetracycline (TC) in an aqueous medium under simulated solar light irradiation. The SnS2 nanostructures synthesized with these solvents were characterized using various structural, morphological, and optical techniques, including x-ray diffraction, RAMAN, field emission scanning electron microscope, x-ray photoelectron spectroscopy, UV–Vis, and Brunauer–Emmett–Teller analysis. The choice of solvent was found to significantly affect the structural, morphological, and optical properties of the SnS2 nanostructures. Notably, the sample synthesized with EN as the solvent displayed a unique morphology, enhanced light-harvesting ability, efficient charge carrier separation, and a larger specific surface area, all of which contributed to its superior photocatalytic activity. This sample achieved 99.9% degradation of MB and 95% degradation of TC within 20 and 40 min, respectively. The kinetic analysis revealed maximum rate constant (k) values of 0.15242 min−1 for MB and 0.060 95 min−1 for TC, as determined by the pseudo-first-order kinetic model. We also discuss the plausible mechanism involving visible light-induced electron–hole pairs that generate reactive species, leading to the mineralization of dyes into H2O, CO2, and other gaseous products. The synthesized SnS2 nanostructures demonstrate significant potential for enhanced photocatalytic activity in organic pollutant degradation, underscoring their promise in addressing water pollution challenges.
Self-similarity of multilayer networks
Authors: Wang 王 Bing 冰 , Yu 于 Huizhi 蕙芷 , Wei 魏 Daijun 代俊 
Published: October 2024

Abstract
Research on the self-similarity of multilayer networks is scarce, when compared to the extensive research conducted on the dynamics of these networks. In this paper, we use entropy to determine the edge weights in each sub-network, and apply the degree–degree distance to unify the weight values of connecting edges between different sub-networks, and unify the edges with different meanings in the multilayer network numerically. At this time, the multilayer network is compressed into a single-layer network, also known as the aggregated network. Furthermore, the self-similarity of the multilayer network is represented by analyzing the self-similarity of the aggregate network. The study of self-similarity was conducted on two classical fractal networks and a real-world multilayer network. The results show that multilayer networks exhibit more pronounced self-similarity, and the intensity of self-similarity in multilayer networks can vary with the connection mode of sub-networks.
Exact quantum dynamics for two-level systems with time-dependent driving
Authors: He 贺 Zhi-Cheng 郅程 , Wu 吴 Yi-Xuan 奕璇 , Xue 薛 Zheng-Yuan 正远 
Published: October 2024

Abstract
It is well known that the time-dependent Schrrödinger equation can only be solved exactly in very rare cases, even for two-level quantum systems. Thus, finding the exact quantum dynamics under a time-dependent Hamiltonian is not only fundamentally important in quantum physics but also facilitates active quantum manipulations for quantum information processing. In this work, we present a method for generating nearly infinite analytically assisted solutions to the Schrödinger equation for a qubit under time-dependent driving. These analytically assisted solutions feature free parameters with only boundary restrictions, making them applicable in a variety of precise quantum manipulations. Due to the general form of the time-dependent Hamiltonian in our approach, it can be readily implemented in various experimental setups involving qubits. Consequently, our scheme offers new solutions to the Schrödinger equation, providing an alternative analytical framework for precise control over qubits.
Experimental test of an extension of the Rosenzweig–Porter model to mixed integrable-chaotic systems experiencing time-reversal invariance violation
Authors: Zhang 张 Xiaodong 晓东 , Che 车 Jiongning 炯宁 , Dietz Barbara 
Published: October 2024

Abstract
We report on the theoretical and experimental investigations of the transition of a typical quantum system with mixed regular-integrable classical dynamics to one with violated time-reversal (

T

) invariance. The measurements are performed with a flat superconducting microwave resonator with circular shape in which chaoticity is induced by using either long antennas or inserting two circular disks into the cavity, and by magnetizing a ferrite disk placed at its center, which leads to violation of

T

invariance. We propose an extension of the Rosenzweig–Porter (RP) model, which interpolates between mixed regular-chaotic instead of integrable dynamics and fully chaotic dynamics with violated

T

-invariance, and derive a Wigner-surmise like analytical expression for the corresponding nearest-neighbor spacing distribution. We propose a procedure involving this result and those for the RP model to determine the size of

T

-invariance violation and chaoticity and validate it employing the experimental eigenfrequency spectra.
Higher-order topological corner states and origin in monolayer LaBrO
Authors: Wang 王 Qing 庆 , Hao 郝 Ning 宁 
Published: October 2024

Abstract
Intrinsic higher-order topological insulators driven solely by orbital coupling are rare in electronic materials. Here, we propose that monolayer LaBrO is an intrinsic two-dimensional second-order topological insulator. The generalized second-order topological phase arises from the coupling between the 5d orbital of the La atom and the 2p orbital of the O atom. The underlying physics can be thoroughly described by a four-band generalized higher-order topological model. Notably, the edge states and corner states of monolayer LaBrO exhibit different characteristics in terms of morphology, number, and location distribution under different boundary and nanocluster configurations. Furthermore, the higher-order topological corner states of monolayer LaBrO are robust against variations in spin–orbit coupling and different values of Hubbard U. This provides a material platform for studying intrinsic 2D second-order topological insulators.
Multi-feature Fusion Recognition Method of Rail Surface State Based on SVM Algorithm
Authors: Liu Lili , Zuo Jihong , Yang Chuanyin , Tang Yufeng 
Published: October 2024

Abstract
In order to solve the problems that the rail surface status is still judged by manual experience and the recognition efficiency is low, a multi-feature fusion recognition method of rail surface status based on SVM algorithm is proposed. First, the rail surface image database is obtained by preprocessing the collected rail surface images in different states. The preprocessing includes image graying, image denoising and image extraction. Then, the gray mean and variance of the contact surface region are calculated to describe the color features of the rail surface image. And the texture features of the contact surface region are extracted using the gray level co-occurrence matrix. Then the two features are fused as the basis for judging the rail surface state. SVM is used to recognize the rail surface state. Finally, the proposed method is verified and analyzed by experimental simulation, and the results prove the effectiveness of the proposed method.
VMD-BiGRU for Short-term Power Load Forecasting with Energy Valley Optimizer Enhancement
Authors: Lai Yibo , Wang Qifeng , Chen Gang , Sun Quan , Liao Xiaojing , Shen Zhilong , Bai Yu 
Published: October 2024

Abstract
Electrical load, given context of this modern era, is recognized to have distinct characteristics: diversity, flexibility, and inherently, non-linearity and temporality. Aiming to leverage these characteristics and counteract the challenges within, we propose an electrical load forecasting method, namely EVO-VMD-BiGRU. The proposed technique initiates by utilizing Variational Mode Decomposition (VMD) for the breakdown of the load data into constituent modes, extract the principal modes, and merge them with the features of air temperature, wind speed, precipitation, electricity price and holidays. The modes are then fed to the BiGRU model for training to forecast. The Energy Valley Optimizer (EVO) is applied to search for optimal hyperparameters of the BiGRU model, with the objective of minimizing the RMSE, in order to obtain models for each mode. Finally, the method utilizes these models to forecast the values of each mode, summing them to generate the final predictions. T The efficacy of this approach was confirmed through testing on load datasets sourced from Singapore and Australia. The proposed method achieved an RMSE of 81.20 MW and 30.15 MW on the respective datasets, the MAPE of 0.79% and 0.47%, and the R-squared (R2) of 0.99 and 0.99, which are superior to the alternative methods in the experiments. Results show that the proposed method achieves superior outcomes in short-term electricity load forecasting and exhibits promising potential for practical use.