bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy spectrum of basic electrons in Pb1–xSnxTe in the vicinity of the magnetic phase transition
Authors: Bratashevskii Yu. A. , Prozorovskii V. D. , Kharionovskii Yu. S.
Published: November 2024

Independent studies of diamagnetic resonance and dispersion of helicon waves revealed a marked rearrangement of the energy spectrum of basic electrons in n-type Pb1–xSnxTe single-crystal specimens in the vicinity of the ferromagnetic ordering of the system in the temperature range from 1.7 to 8°K. When the specimens are heated by 3 to 4°K, the coefficient of effective-mass anisotropy more than doubles and the transverse effective electron mass decreases by more than 30%.
“Anomalous” behavior of quantum oscillations of transport kinetic coefficients in the magnetic breakdown regime
Authors: Ginzburg VI. L. , Slutskin A. A.
Published: November 2024

The quantum magnetic breakdown oscillations of the static conductivity tensor and of the thermoelectric power in metals with specific “difference” periods, absent in the oscillations of thermodynamic properties, are considered. The treatment is based on the quantum kinetic equation under the assumption that the frequency of electron collisions with dislocations is much higher than the electron-impurity collision frequency, but much lower than the characteristic Larmor frequency. It is shown that a specific “interaction” exists between the “difference” harmonics and the giant magnetic breakdown oscillations of kinetic coefficients, leading to a significant enhancement of the “difference” harmonic amplitudes. The theory developed explains a number of recently observed experimental data.
The ESR spectrum and spin-lattice relaxation of dislocation spin chains
Authors: Vinokur V. M. , Kravchenko V. Ya.
Published: November 2024

We study the structure of the ESR spectrum of the dislocation spin system in silicon. It is shown that its features can be explained by the existence of different types of dislocations in the deformed crystal. The temperature dependence of the spin-lattice relaxation time τ is obtained. It is shown that the anomalously weak temperature dependence of τ in the region where Raman scattering dominates is due to dislocation-localized phonons which play the main role in the spin-lattice energy exchange.
Motion of ferroelectric domain boundaries in strong fields
Authors: Fedosov V. N. , Chursina E. I.
Published: November 2024

The structure is found for a domain wall moving in a constant external field and the polarization wave spectrum is investigated.
A minimum in the resistance of beryllium
Authors: Tszyan Yu. N. , Ordynets A. G.
Published: November 2024

The temperature dependence of the resistance of single crystal beryllium specimens with widely varying impurity concentrations is studied in a longitudinal magnetic field over the temperature range 4.2–20 °K. It is demonstrated that the resistance changes nonmonotonically with temperature, and that application of a magnetic field of H∼10–20 kOe eliminates this anomalous resistance behavior. On the basis of the experimental data the preliminary conclusion is drawn that the observed resistance behavior is produced by magnetic impurities (the Kondo effect).
Long-term relaxation of orientational disorder and structural modifications in molecular nitrogen at high pressure
Authors: Tschauner Oliver , Navon Oded , Schmidt Christian , Wirth Richard , Weiss Yaakov , Kempe Yael , Remennik Sergei , Liu Wenjun , Chariton Stella , Prakapenka Vitali B.
Published: November 2024

Up to 17 GPa, the crystalline phases of N2 are characterized by pronounced orientational disorder, whereas the higher-pressure phases of molecular N2 are ordered. This raises the question about long-term relaxation of orientational disorder within the low- to intermediate-pressure regime. Here, this question is addressed by comparing synthetic with natural, chemically pure, solid N2 that resides as inclusions in diamonds at 300 K for about 108 years at pressures up to 11 GPa. It is shown that disorder prevails at 8.7 GPa, 300 K, where both synthetic and natural N2 assume the same structure. However, at 10.8 GPa, natural solid N2 exhibits monoclinic distortion and partial orientational ordering of the molecules, both of which are not observed in synthetic material. This difference is interpreted as the result of long-term structural relaxation. The ordering mechanism is examined and placed into the context of the δ- to ε-N2 transition. We present explanations for the absence of complete ordering of δ-N2.
Fabrication of disk ultramicroelectrode using nanoskiving method
Authors: Geng Yanquan , Zhao Hainan , Yan Yongda , Fang Zhuo , Wang Jiqiang
Published: November 2024

The detection time of the ultramicroelectrode can be reduced to nanoseconds when compared to the macroscopic electrode, enabling real-time monitoring of the instantaneous electrochemical behavior of the microstructure. Preparing ultramicroelectrode thus has drawn great attention recently. In the present study, a novel method for the preparation of disk ultramicroelectrodes with controllable electrode end sizes based on the nanoskiving method is proposed. The feature dimensions of the ultramicroelectrode can be controlled by the nanoskiving parameters. The electrochemical performance of the prepared ultramicroelectrode is evaluated in the solution system consisting of a 1 mM FcMeOH (ferrocenyl methanol) and 0.1 M KCl aqueous solution. The steady-state limit current deviation rate of the electrode is 7%, and it can work continuously for 600 s. Moreover, the electrode is integrated with micrometer precision scanning and positioning devices, which conduct electrochemical characterization of the micron structure array sample. The electrochemical image of the tin-doped indium oxide sample is measured successfully. The funding in this study provides a novel method to prepare ultramicroelectrodes. Importantly, high-precision electrochemical imaging equipment is established that can be used to measure electrochemical images.
Photon localization transition in a magnetorheological fluid
Authors: Sahoo Himadri , Parekh Kinnari , Masud Laskar Junaid , Mujumdar Sushil
Published: November 2024

We investigate photon transport in magnetically tunable fluids, specifically magnetic nanofluids and magnetorheological fluids (MRFs). Our study focuses on the statistical analysis of light transport in these fluids, with a particular focus on earlier theoretical proposals related to the possibility of Anderson localization in these systems. We employ a well-known mesoscopic quantifier, the generalized conductance, to assess the domain of light transport in these systems. Magnetic nanofluids, which contain nanometer-sized magnetite particles, exhibit weak scattering with no substantial consequence on conductance, regardless of the applied magnetic field. In contrast, magnetorheological fluids, a bidispersion of micrometer-sized magnetizable spheres in a magnetic nanofluid, show a decrease in conductance to values below unity as the magnetic field strength increases. This decrease occurs at the magnetic-field-induced photonic bandgap in MRFs, which plays a crucial role in the localization process and is characterized by reduced transmitted intensity, altered speckle patterns, and significant changes in intensity statistics. Our findings also highlight the temporal evolution of field-induced speckles, where the initial high correlation decreases over time, and the correlation width widens indicating that the duration of sustained correlation enhances as the system reaches equilibrium. Consequently, the evolution of field-induced scatterers in MRFs significantly emulates light localization effects as the system attains equilibrium. This study concludes that our system is a prime candidate to observe possible strong localization in a magnetically tunable, dissipative complex system. Such systems hold potential applications in optical switching, adaptive optics, and smart materials design through controlled light manipulation using external magnetic fields.
Al@Al2O3 core-shell plasmonic design for the dilemma between high responsivity and low dark current of MoS2 photodetector
Authors: Shen Ziquan , Wang Wanyu , Xu Zhe , Shi Kaixi , Li Jinhua , Fang Xuan , Xu Mingze
Published: November 2024

The localized surface plasmon resonance (LSPR) effect induced by metal nanoparticles (NPs) can solve the problem of low light absorption in two-dimensional (2D) materials limited by atomic scale. However, the accompanying problem is the rise in dark current due to plenty of electrons from metal NPs injecting into the 2D materials, which decreases the performance of plasmonic photodetectors. Here, we designed the structure of Al NPs coated with Al2O3 by low temperature oxidation treatment method to balance the dilemma between high photoresponse and low dark current. Raman spectrum and finite-difference time-domain simulations were used to verify that Al2O3 does not affect the LSPR effect of Al NPs. Compared to that of the pristine MoS2/Al photodetector, the MoS2/Al@Al2O3 plasmonic photodetector achieved a fourfold decrease in dark current, threefold increase in detectivity, and 1.5-fold increase in responsivity. As a result, the optimized plasmonic device achieves a high responsivity of ∼1719 A/W, an excellent detectivity of ∼6.0 × 1011 Jones, and an ultra-fast response speed of ∼15 ns. Our work reveals that constructing metal NPs covered by ultra-thin oxide layer is a feasible strategy for plasmonic photodetectors to decrease dark current and achieve high performance index.
The influence of wildfire risk reduction programs and practices on recreation visitation
Authors: White Eric M. , Winder Samantha G. , Wood Spencer A.
Published: November 2024

Background The increasing extent and severity of uncharacteristic wildfire has prompted numerous policies and programs promoting landscape-scale fuels reduction. Aims We used novel data sources to measure how recreation was influenced by fuels reduction efforts under the US Forest Service Collaborative Forest Landscape Restoration (CFLR) Program. Methods We used posts to four social media platforms to estimate the number of social media user-days within CFLR landscapes and asked: (1) did visitation within CFLR Program landscapes between 2012 and 2020 change in a manner consistent with the pattern on nearby lands, and (2) was there a relationship between the magnitudes of specific fuel treatment activities within CFLR landscapes and visitation to that landscape? Key results In aggregate, visitation to the CFLR landscapes changed at a rate mirroring the trend observed elsewhere. Within CFLR landscapes, pre-commercial thinning and pruning had slight positive influences on visitation whereas prescribed burning and managed wildfire had slight negative influences. Conclusions Fuel treatments can have a modest influence on visitation, but we didnot find any wholesale changes in visitation within CFLR landscapes. Implications Social media and other novel data sources offer an opportunity to fill in gaps in empirical data on recreation to better understand social-ecological system linkages.
Social learning with complex contagion
Authors: Chiba-Okabe Hiroaki , Plotkin Joshua B.
Published: November 2024

Traditional models of social learning by imitation are based on simple contagion—where an individual may imitate a more successful neighbor following a single interaction. But real-world contagion processes are often complex, meaning that multiple exposures may be required before an individual considers changing their type. We introduce a framework that combines the concepts of simple payoff-biased imitation with complex contagion, to describe how social behaviors spread through a population. We formulate this model as a discrete time and state stochastic process in a finite population, and we derive its continuum limit as an ordinary differential equation that generalizes the replicator equation, a widely used dynamical model in evolutionary game theory. When applied to linear frequency-dependent games, social learning with complex contagion produces qualitatively different outcomes than traditional imitation dynamics: it can shift the Prisoner’s Dilemma from a unique all-defector equilibrium to either a stable mixture of cooperators and defectors in the population, or a bistable system; it changes the Snowdrift game from a single to a bistable equilibrium; and it can alter the Coordination game from bistability at the boundaries to two internal equilibria. The long-term outcome depends on the balance between the complexity of the contagion process and the strength of selection that biases imitation toward more successful types. Our analysis intercalates the fields of evolutionary game theory with complex contagions, and it provides a synthetic framework to describe more realistic forms of behavioral change in social systems.
CO
2
protects cells from iron-Fenton oxidative DNA damage in
Escherichia coli
and humans
Authors: Fleming Aaron M. , Dingman Justin C. , Burrows Cynthia J.
Published: November 2024

While hydroxyl radical is commonly named as the Fenton product responsible for DNA and RNA damage in cells, here we demonstrate that the cellular reaction generates carbonate radical anion due to physiological bicarbonate levels. In human and
Escherichia coli
models, their transcriptomes were analyzed by RNA direct nanopore sequencing of ribosomal RNA and chromatography coupled to electrochemical detection to quantify oxidation products in order to follow the bicarbonate dependency in H
2
O
2
-induced oxidation. These transcriptomic studies identified physiologically relevant levels of bicarbonate focused oxidation on the guanine base favorably yielding 8-oxo-7,8-dihydroguanine (OG). In human cells, the bicarbonate-dependent oxidation was further analyzed in the metabolome by mass spectrometry, and a glycosylase-dependent qPCR assay to quantify oxidation sites in telomeres. These analyses further identify guanine as the site of oxidation when bicarbonate is present upon H
2
O
2
exposure. Labile iron as the catalyst for forming carbonate radical anion was demonstrated by repeating the bicarbonate-dependent oxidations in cells experiencing ferroptosis, which had a >fivefold increase in redox-active iron, to find enhanced overall guanine-specific oxidation when bicarbonate was present. The complete profiling of nucleic acid oxidation in the genome, transcriptome, and metabolome supports the conclusion that a cellular Fe(II)-carbonate complex redirects the Fenton reaction to yield carbonate radical anion. Focusing H
2
O
2
-induced oxidative modification on one pathway is consistent with the highly evolved base excision repair suite of enzymes to locate G-oxidation sites for repair and gene regulation in response to oxidative stress.
In search of home
Authors: Kjærgård Jonas Ross
Published: November 2024

Secret History tells the story of two sisters, Mary and Clara, who have joined
Clara’s husband as he attempts to regain his lost colonial possessions in the final period of the Haitian Revolution.
In contrast to the frights she experiences in war-ridden Saint-Domingue, Mary dreams longingly of a stable home. This
chapter analyzes the novel’s dichotomy of horrifying fear and happy dreams on the level of figurative language,
composition, and literary geography. It argues that Secret History engages with the specific
challenge of forging a North-American cultural identity. The chapter also explores Sansay’s use of the sentimental
mode, showing that it is used to interrogate the humanity of friends and foes, enslaved and free.
Showing and feeling the atrocities of slavery
Authors: Köhler Sigrid G.
Published: November 2024

German-language playwrights inscribed themselves into the international debate on abolition at the
end of the 18th century, making themselves part of a transnational political communicative space. Most of these
authors are rarely read today, except for August von Kotzebue, the most frequently performed German-language author of
this period. These authors usually conceived their plays as discourse dramas that reflected the contradiction between
the ideals of the Enlightenment and the system of enslavement and denounced slavery as a violation of human rights. To
this end, as an analysis of Kotzebue’s play The Negro Slaves will show, they transgress the
sentimentalist aesthetics prevailing in contemporary theatre and develop an implicit poetics and aesthetics of what I
call the ‘drastic.’
Melodramatic tableaux vivants
Authors: Simonsen Karen-Margrethe
Published: November 2024

The novel Sab (1841) by the Cuban-Spanish writer Gertrudis Gómez de Avellaneda has
been called both a radical anti-slavery novel (Sommer 1991, Davies 2013) and an anti-abolitionist novel that only pays lip service to the
abolitionist cause (Williams 2008, Gomariz, 2009). In this article I approach this ambiguity by moving the focus from content to form and
from story to reader. Building on insights by Peter Brooks (1976), Jacky Bowring (2017) and David Denby
(1994), I argue that formally the novel is a melodramatic tragedy and that its melodramatic tableaux
vivants foster moral reflection in the reader by creating a clash between the ideal and the real and between surface
and depth. I develop this in critical dialogue with ideas about the (dis)connection between emotionality, empathy and
human rights developed by Lynn Hunt (Hunt 2007) and Lynn Festa (2006).
“No one can imagine my feelings”
Authors: Dwyer Erin Austin
Published: November 2024

This chapter details the ideological foundations of the emotional norms of slavery and debates over
whether those practices and feelings were tied to race or to slave status. It examines how theories of racialized
emotional difference circulated, and the proslavery ramifications of those ideas, as well as how formerly enslaved
people used the medium of slave narratives to refute white supremacist ideas about their affective inferiority and
subvert the expectations of sentimental audiences. Abolitionists’ argument that emotional differences were rooted in
slave status, not race, jeopardized proslavery ideology and individual slaveholders, as it meant that after
Emancipation, black people would expect the same emotional liberty as free people.
Haunting slavery
Authors: Robison Lori
Published: November 2024

This chapter considers the disruptive power of two nineteenth-century literary scenes, one from
Harriet Beecher Stowe’s Uncle Tom’s Cabin (1852) and one
from Lydia Maria Child’s A Romance of the Republic (1867),
in which portrayals of enslaved women activate the emotions of readers while challenging the usual workings of
sympathy. Drawing on the work of film theorist Todd McGowan, it locates in these scenes a Lacanian gaze that unsettles
readers by looking back at them, creating an opportunity for them to see ideology as ideology. Through this approach,
the chapter identifies a textual strategy that challenges slavery and racism while pushing back against the racial
objectifications inherent in the dynamics of sympathy: a strategy that could ultimately intervene in the cultural
construction of whiteness and blackness.
The blood-stained-gate
Authors: Murphy Laura T.
Published: November 2024

This chapter suggests that the slave narrative employs metonymy as an archive of memory when
authors are unwilling or unable to articulate the experience of trauma explicitly. Drawing on Frederick Douglass’s use
of the “blood-stained gate” metaphor as a repository for his emotional suffering, it describes how blood serves as a
metonymic vehicle for communicating authenticity in narratives in which affective descriptions run counter to the
ambitions of the genre. Ismael Beah’s A Long Way Gone: Memoirs of a Boy Soldier (2007) and Emmanuel
Jal’s War Child (2008) present contrasting cases of
blood’s capacity to serve as a repository for the emotional content of war. The trope of blood is then is used a lens
for understanding why audiences respond skeptically to slave narratives and suggests a less suspicious reading
practice among scholars and activists.
Reflecting on the LK-99 fervour: insights and future prospects
Authors: Sukhenko I V , Karbivskyy V L
Published: November 2024

A Copper-substituted lead apatite, named LK-99 by its authors, has recently emerged as a candidate for the world’s first ambient-conditions superconductor, but has since not demonstrated the anticipated properties when subject to independent scrutiny. In this review we cover the experimental and theoretical studies that have been dedicated to this unusual material, while briefly discussing the original arXiv papers. So far, all the synthesis methods result in the formation of a multiphase material with unpredictable structure and unstable stoichiometry. This is a core reason why the studies discussed in the review yield different results when it comes to magnetic, electrophysical properties and even visual appearance of the material. DFT studies of the electronic structure of Pb9Cu(PO4)6O are reviewed and compared with our original calculations, and the limitations of the DFT approach are discussed. While reviewing theoretical publications on the matter, we bring forward the flat-band superconductivity model and discuss the nature of flat bands and their ability to sustain superconducting transport in the model material. The possibility of the compound being a Mott insulator, given the specifics of its electronic structure, as well as the role of doping, is highlighted. Finally, we raise the question of viability of achieving superconductivity in doped apatites beyond the LK-99 formula.
First principle calculations of structural, electronic, and optical properties of XSnO3 (X: Ca, Mg, Sr) perovskite oxides
Authors: Larbi Rekia , Candan Ilhan , Cakmak Azad , Sahnoun Omar , Sahnoun Mohamed
Published: November 2024

The perovskite oxides XSnO3 have garnered significant attention due to their potential applications in various fields, including electronics, photonics, and renewable energy technologies. This study presents a comprehensive theoretical investigation of the structural, electronic, and optical properties of XSnO3 (X: Ca, Mg, Sr) compounds with density functional theory based on the full potential linearized augmented plane wave method. Our analysis begins with thoroughly examining the structural stability and lattice parameters of XSnO3 compounds, revealing their robust perovskite crystal structures. These compounds’ lattice constants, total energy, bulk modulus, and cohesive energy were determined. Subsequently, we delve into the electronic properties of XSnO3, elucidating their electronic band structures, density of states, and charge densities. The studied compounds are indirect bandgap semiconductors having band gaps in the visible range. Furthermore, our investigation extends to the optical properties of XSnO3, encompassing absorption spectra, refractive indices, energy loss function, reflectivity, extinction coefficient, and dielectric functions across a wide range of wavelengths. Overall, the excellent optical properties of these compounds make them suitable for optoelectronic applications.
Engineering the band structure of type-II MoSe2/WSe2 van der Waals heterostructure by electric field and twist angle: a first principles perspective
Authors: Yu Fangqi , Yang Weihua , Kang Jun , Huang Rao , Li Lei , Wen Yuhua
Published: November 2024

Type-II heterostructures composed of transition-metal dichalcogenides have attracted enormous attention due to their facilitation in efficient electron–hole separation. In this work, we performed density-functional theory calculations to systematically investigate the atomic and electronic structures of MoSe2/WSe2 van der Waals heterostructure. Its six high-symmetry configurations with different interlayer coupling under external electric field and twist angle were addressed. Our results reveal that all the configurations exhibit type-II band alignment and their band gaps can be effectively modulated by the electric field. Notably, the direct to indirect band gap transition only occurs in the configurations with strong interlayer coupling. Moreover, twist-induced symmetry breaking weakens the interlayer interactions, thus decreasing interlayer charge transfer. Owing to large interlayer distance and weak interlayer coupling, the band structure of the heterostructure remained unchanged for the twist angles ranging from 13.2° to 46.8°. These findings demonstrate the great potential of the MoSe2/WSe2 heterostructure for applications in optoelectronic and nanoelectronic devices.
Quantum spin-liquid in Ba3CuSb2O9 epitaxial thin films
Authors: Kaipamangalath Aswathi , Pathak Riya , Akram Wasim , Nath Ramesh , Maity Tuhin
Published: November 2024

Hexagonal perovskite materials are emerging quantum spin liquid (QSL) systems providing a fertile ground to realize novel quantum phenomena. The epitaxially grown thin films of such materials offer a compelling approach to utilize exotic quantum phases for device applications with better control over the structure. We fabricate the intriguing QSL triple perovskite Ba3CuSb2O9 epitaxially onto a MgO (100) substrate by pulsed laser deposition technique as well as in bulk form for comparison. The presence of only (00l) parallel planes of Ba3CuSb2O9 in x-ray diffraction validates the epitaxial growth of the thin film. Temperature-dependent magnetization of thin film reveals no magnetic ordering down to 400 mK, with a large antiferromagnetic Curie–Weiss temperature (

θ

CW

≈
−

11.68 K). This indicates strong magnetic frustration and QSL behaviour, similar to bulk Ba3CuSb2O9. The presence of magnetic correlations at low temperature (in the quantum spin liquid state) is further confirmed by analysing the low temperature magnetic isotherms. These experimental findings underscore the potential of this quantum material for its use in quantum technologies.
Dynamic calibration of a high-resolution wind tunnel model for ultra-low-range fluctuating surface pressure measurement
Authors: Schmeer Joy , Hayden Paul , Birch David M
Published: November 2024

Measuring surface pressures in a low-speed wind tunnel which are well-resolved in both space and time can be particularly challenging. A technique has therefore been developed for the simultaneous dynamic calibration of large numbers of pressure tappings on a wind tunnel model. A portable, variable-volume plenum is used to calibrate the model in situ. A forcing function consisting of sequential sinusoids at varying frequencies is used to obtain the spectral responses, with feedback control implemented to ensure consistent amplitudes independent of the plenum’s own dynamics. This discrete calibration technique is shown to significantly reduce uncertainty propagation compared to white noise, chirp or step functions. The effectiveness of the dynamic calibration is validated against laser diagnostics in turbulent flow. As a demonstration of the capability of this technique, spatially-resolved surface pressure statistics are then presented for the five wetted faces of a cube in an atmospheric wind tunnel turbulent boundary layer.
Chemo-mechanical benchmark for phase-field approaches
Authors: Kannenberg Thea , Prahs Andreas , Svendsen Bob , Nestler Britta , Schneider Daniel
Published: November 2024

Phase-field approaches have gained increasing popularity as a consequence of their ability to model complex coupled multi-physical problems. The efficient modeling of migrating diffuse phase boundaries is a fundamental characteristic. A notable advantage of phase-field methods is their ability to account for diverse physical driving forces for interfacial motion due to diffusive, mechanical, electro-chemical, and other processes. As a result of this versatility, phase-field methods are frequently employed in the fields of materials science, mechanics, and physics, and are continually undergoing development. To test the accuracy of these developments, it is indispensable to establish standardized benchmark tests, to ensure the thermodynamic consistency of studies carried out. This work presents a series of such tests based on chemo-elastic equilibrium states for Fe-C binary alloys, benchmarking the performance of a phase-field model with chemo-elastic coupling based on the grand potential density. Use of parameters for the Fe-C system from a Calphad database allows for the determination of the Gibbs free energy, thereby enabling the quantification of chemical driving forces. For a circular inclusion, the capillary driving force is derived on a geometrically motivated basis using the lever rule and expressed as a function of the chemical potential. These simulations contribute to the development of standardized benchmark tests that validate chemical, capillary, and mechanical driving forces separately and in combination. The present study compares phase-field simulation results with results from the analytic solution of chemo-elastic boundary value problems and the generalized Gibbs–Thomson equation.
Synthesis of nitrogen-doped carbon dot/tin disulfide nanosheet composite electro-catalysts for dye-sensitized solar cells
Authors: Chen Lin-Jiun , Yu Cheng-Ju , Sahoo Prasanta Kumar , Wang Yu-Xuan , Lin Yi-Xuan , Lee Chuan-Pei
Published: November 2024

Nitrogen-doped carbon dots (N-CDs) and vertically-grown tin disulfide (SnS2) nanosheets are synthesized via hydrothermal method and chemical vapor deposition technique, respectively. The SnS2 nanosheets are directly fabricated on flexible carbon cloth (CC), and then their basal planes are decorated with N-CDs. The as-prepared composite electrodes are used as the counter electrode for the application in dye-sensitized solar cells (DSSCs). The characterizations of N-CDs and SnS2 nanosheets are studied by high resolution transmission electron microscopy, scanning electron microscopic, energy dispersive x-ray spectrometer, Raman spectrometer and x-ray photoelectron spectroscopy etc. Moreover, the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and photocurrent-density voltage are utilized to understand the electro-catalytic performance of N-CDs/SnS2/CC composite counter electrode. The N-CDs/SnS2/CC composite electrode shows higher cathodic reduction current density and lower charge transfer resistance in CV and EIS measurements, respectively, as compared to those of the electrodes with N-CDs or SnS2 alone. Meanwhile, the DSSC using N-CDs/SnS2/CC exhibits cell efficiency (η) of 7.68%, which is higher than those of cells having SnS2/CC (η = 7.54%) and N-CDs/CC (η = 5.66%) counter electrodes, respectively; it also reaches 94% cell efficiency of the cell using Pt/CC counter electrode (η = 8.15%). The design concept of the modification of the basal planes by defect-rich carbon dots (i.e. N-CDs) and highly-exposed edge sites (i.e. vertically-grown SnS2 nanosheets) makes promising route to enhance the performance of two-dimensional electro-catalysts.
Insights into stripping losses of negative ions in an ITER-like pre-acceleration system
Authors: Navarro A , Barnes M , den Harder N , Wünderlich D , Fantz U
Published: November 2024

The ELISE test facility at IPP Garching hosts an RF-driven negative hydrogen ion source and extraction and acceleration system. Its target is to demonstrate the performance foreseen for the ITER neutral beam injection (NBI) system in terms of extracted current density (329 A m−2 in hydrogen, 286 A m−2 in deuterium), electron-ion-ratio (

<

1) and pulse length (up to 3600 s in deuterium and 1000 s in hydrogen). NBI systems are compromised by a process commonly known as stripping losses (neutralization of negative ions before they achieve full acceleration). According to theoretical estimations, for a source filling pressure of

p

fill

=
0.3

Pa, 29% of the extracted

H

−

/

D

−

ions are lost by stripping in the ITER full-scale NBI system. Experimentally, stripping losses are monitored using Beam Emission Spectroscopy (BES). Previous experimental measurements of the stripping losses at ELISE yielded values around 1.7%, which were much lower than the 10% predicted for the pre-accelerator system. The notable difference has sparked concern about the conventional interpretation of the BES experimental measurements used at IPP. The Bavarian Beam Code for Negative Ions (BBCNI) is a full 3D particle tracking code that can also produce synthetic BES spectra. BBCNI is used to evaluate how accurately different analysis techniques determine the stripping losses from the BES. This is achieved by comparing the results with the total simulated count of stripping losses. The analysis method that produces the most accurate results is identified and then systematically applied to evaluate ELISE’s data from various experimental campaigns. For a nominal source filling pressure

p

fill

=
0.3

Pa an average of 5.8% is measured experimentally when evaluating the data with this method. Although higher than previously determined with BES, stripping losses are still smaller than predicted values. This may open the option to increase the filling pressure in the source as a means to facilitate achieving the targeted ITER conditions.
Numerical simulation of YSO jet collimated by toroidal magnetic fields and radiative cooling effect
Authors: Feng Li , Lv Chong , Yuan Wenqiang , Sun Wei , He Chuangye
Published: November 2024

The mechanism of generation and collimation of young stellar object jets remains an unsolved problem and is a research hotspot in contemporary astrophysics. Here, we conducted a two-dimensional cylindrical coordinates simulation experiment using radiative magnetic-hydro-dynamic FLASH code and systematically analyzed the effects of toroidal magnetic fields generated by Biermann battery term and radiative cooling effect on jet evolution. In the simulation, strong toroidal magnetic fields are generated at the boundary of the plasma flow. A comparison of jets generated in different cases indicates that the magnetic fields play a significant role in hydrocarbon (CH) plasma jet collimation, surpassing the impact of radiative cooling effects. Additionally, it is observed that the magnetic fields can alter knots velocities. This platform provides a way to investigate the role of toroidal magnetic fields in jet evolution without external devices and provides a better understanding of the evolution of protostellar jets.
Role of magnetic doping in topological HgTe and application of the Gram–Schmidt method for computing impurity states in quantum wells
Authors: Bugajewski D , Dietl T
Published: November 2024

The quantum spin Hall effect in non-magnetic and Mn-doped HgTe quantum well (QW) is strongly affected by Kondo scattering of edge electrons by holes localized on acceptors. A generalized eigenvalue method is usually employed for determining impurity binding energies from the multiband Kohn–Luttinger Hamiltonians in bulk samples and semiconductor quantum structures. Such an approach provides accurate values of the level positions but its applicability for determining the impurity localization radius can be questioned. As an alternative method we propose here the Gram–Schmidt orthogonalization procedure allowing to employ the standard eigenvalue algorithms and, thus, to determine both impurity level energies and the set of normalized eigenvectors. We apply this approach to singly-ionized acceptor states in HgTe QWs and obtain impurity level energies and localization radiuses even for states degenerate with the continuum of band states. Such information allows us to assess the energy of bound magnetic polarons in QWs doped with magnetic ions. We determine the polaron energies and discuss consequences of the resonant polaron formation on band transport in the bulk samples and QWs in the regimes of quantum Hall effects.
Study on the friction and wear properties of nickel-based-WC-10Ni composite coatings prepared on the surface of TC4 titanium alloy
Authors: Ma Shangbo , Xu Xiangping , Wang Xiling , Feng Yizheng , Xia Chunzhi , Teng Hong
Published: November 2024

A nickel-based WC-10Ni composite coating was fabricated via vacuum brazing at 1160 °C, using TC4 titanium alloy as the matrix, WC-10Ni powder as the hard phase, and BNi-5 as the brazing material. The study examined the coating’s microstructure and analyzed the impact of the WC-10Ni ratio and friction test temperature on its wear resistance, alongside a discussion of the wear mechanism. The results revealed that the hard layer of the composite coating comprised TiC, W, and minor amounts of Ti5Si3 and α-Ti, while the interface layer displayed a network structure of Ti2Ni and Ti5Si3. Using a Si3N4 ceramic ball as the counter-wear material, under conditions of a 10N load, 318 r min−1 rotational speed, 3 mm wear radius, and 30 min wear duration, the average friction coefficients of the three composite coatings were 0.289, 0.241, and 0.271, and their wear rates were 65.8%, 39.7%, and 52.7% of the substrate, respectively. The 50% WC-10Ni coating exhibited the best wear resistance, with adhesive wear being the dominant mechanism, accompanied by minor abrasive wear. Friction tests on the 50% WC-10Ni coating at 200 °C, 400 °C, 600 °C, and 800 °C revealed that the lowest wear rate, 0.35 × 10−5 mm3 N−1 m−1, occurred at 600 °C, where the average friction coefficient was 0.432 and oxidative wear was predominant. At 800 °C, the coating suffered significant damage, resulting in deteriorated wear resistance.
Rheology-dependent surface wave characteristics in an advanced geomaterial flexoelectric plate with viscoelastic coating
Authors: Seema  , Singhal Abhinav , Tiwari Rakhi , Gupta Vipin , Dutta Rachaita , Ahmad Hijaz , Das Soumik
Published: November 2024

This study investigates the transmission of seismic surface waves in a composite framework comprising a viscoelastic layer overlying a flexoelectric material. The study focuses on understanding the impact of different viscoelastic models (Maxwell, Newtonian, and Kelvin-Voigt) and interface conditions (smooth and welded contact) on the damping and dispersion characteristics of these waves. To achieve this, the study employs a variable-separable technique and appropriate boundary conditions to derive complex frequency relations for electrically open and short circuits scenarios. These relations are subsequently divided into real and imaginary parts to examine the dispersion and dampening properties, respectively. Numerical simulations are conducted to analyze the response of flexoelectric coefficient, viscoelastic layer thickness, and bonding parameter on phase velocity and dampening coefficient. The research findings indicate that the attenuation properties of the Maxwell and Newtonian models are lower compared to the Kelvin-Voigt model. Graphical comparisons highlight the influence of viscoelastic models and interface characteristics on wave propagation. This research can help in the development of sensors, energy harvesters, and wave manipulation devices that employ flexoelectric materials with viscoelastic coatings. Knowledge of surface wave dynamics in these structures is vital for their optimal performance.
A novel scheme for modelling dissipation (gain) and thermalization in open quantum systems
Authors: Kheirandish F , Bolandhemmat E , Cheraghpour N , Moradi R , Ahmadian S
Published: November 2024

In this letter, we introduce a novel method for investigating dissipation (gain) and thermalization in an open quantum system. In this method, the quantum system is coupled linearly with a copy of itself or with another system described by a finite number of bosonic operators. The time-dependent coupling functions play a fundamental role in this scheme. To demonstrate the efficiency and significance of the method, we apply it to some ubiquitous open quantum systems. Firstly, we investigate a quantum oscillator in the presence of a thermal bath at the inverse temperature β, obtaining the reduced density matrix, the Husimi distribution function, and the quantum heat distribution function accurately. The results are consistent with existing literature by appropriate choices for the time-dependent coupling function. To illustrate the generalizability of this method to systems interacting with multiple thermal baths, we study the interaction of a quantum oscillator with two thermal baths at different temperatures and obtain compatible results. Subsequently, we analyze a two-level atom with energy or phase dissipation and derive the spontaneous emission and the pure dephasing processes consistently using the new method. Finally, we investigate the Markovianity in a dissipative two-level system.
Design of magnetic field with high homogeneity for single-turn coil
Authors: Ge Aoming , Pan Ziying , Liu Zhengyang , Yang Haocheng , Lv Yiliang , Peng Tao
Published: November 2024

Single-turn coil (STC) is a kind of destructive pulsed magnet aiming at ultra high magnetic field. In this study, the simple geometry optimization approach to improve the magnetic field homogeneity of STC is proposed. By making the conductor inner surface concave, the amplitude of the magnetic field is decreased by only 15%, while the space volume of the homogeneous magnetic field is increased by 200%–600%. Through three STC examples with different conductor inner diameters and different discharge currents, the effectiveness of this method is validated. In particular, it is theoretically proven that the volume of the homogeneous magnetic field increases as the inner surface concave curvature radius decreases. This geometry optimization method provides the theoretical support for homogeneous field design of STC.
Spectrum of primordial gravitational waves in the presence of a cosmic string
Authors: Azar Ag Ghaleh S. , Abbassi A.M. , Abbassi M.H.
Published: November 2024

In this paper we consider an inflating universe with long straight cosmic string along z-axis. We demonstrate that cosmic string's effect can be treated as a perturbation on the background of FRW metric. By performing cosmological perturbations on this inflating cosmic string background, we derived the linearized Einstein field equations. We show that at leading order (neglecting the mixing terms of cosmic string perturbations with gravitational tensor perturbations), the cosmic string appears as an inhomogeneous term on the right hand side of wave equation for tensor perturbations. Finally, by finding analytical solution of the wave equation for slow-roll inflation, we illustrate its impact on the spectrum of primordial gravitational waves.
Dark photon constraints from CMB temperature anisotropies
Authors: Aramburo-Garcia Andres , Bondarenko Kyrylo , Boyarsky Alexey , Kashko Pavlo , Pradler Josef , Sokolenko Anastasia , Kugel Roi , Schaller Matthieu , Schaye Joop
Published: November 2024

The resonant conversion, within the inter-galactic medium, of regular photons into dark photons amplifies the anisotropy observed in the CMB, thereby imposing stringent constraints on the existence of light dark photons. In this study, we investigate the impact of light dark photons, with masses in the range 3 × 10-15 eV < mA
' < 3 × 10-12 eV on the power spectrum of temperature anisotropies within the cosmic microwave background (CMB) radiation utilizing the state-of-the-art large-volume FLAMINGO cosmological simulations. Our results show that using full Planck data, one can expect the existing constraints on the dark photon mixing parameter in this mass range to improve by an order of magnitude.
Double-well inflation: observational constraints and theoretical implications
Authors: Rodrigues G. , Rodrigues J.G. , dos Santos F.B.M. , Alcaniz J.S.
Published: November 2024

We revisit the small field double-well inflationary model and investigate its observational viability in light of the current Cosmic Microwave Background data. In particular, considering scenarios with minimal and nonminimal coupling between the inflaton field and the Ricci scalar, we perform a Monte Carlo Markov chain analysis to probe the model's parameter space. We also investigate the consequences of the cosmological results in the canonical type-I seesaw mechanism context and obtain constraints on the vacuum expectation value of the inflaton field, together with the amplitude of the coupling to gravity in the nonminimal case. We employ a Bayesian procedure to compare the model's predictions with the Starobinsky inflationary scenario and find a strong statistical preference for the latter against the minimal and nonminimal coupled double-well scenario.
Charge ratio of cosmic ray muons in momentum range ∼ 1 to 3 GeV/c
Authors: Shah Raj , John J.M. , Mondal Suryanarayan , Pethuraj S. , Majumder G. , Shukla P.
Published: November 2024

This work presents the measurements of the cosmic muon charge ratio as a function of full azimuthal angle and momentum within the range of 0.8 to 3.0 GeV/c, using the mini-ICAL detector. The detector, comprising 10 layers of RPCs, has collected cosmic muon data since August 2018 till recent time, at an altitude of 160 m above sea level at the Inter-Institutional Center for High Energy Physics in Madurai, India (9∘56' N, 78∘00' E). The muon charge identification is achieved through the use of a magnetic field of strength 1.4 T. The analysis shows that the cosmic muon charge ratio, Rμ
= N

μ
+/Nμ

-, ranges from 1.1 to 1.2 and has small dependency on the zenith angle. The charge ratio's dependence on momentum and azimuthal angle is thoroughly examined for a wide range of zenith angle upto 50∘. These measurements are compared with the predictions from various combinations of different hadronic models in CORSIKA extensive air shower simulations.
Limits on the parameter space of (3+2) sterile neutrino scenario by IceCube data
Authors: Cabrera Emilse , Esmaili Arman , Quiroga Alexander A.
Published: November 2024

The neutrino sector of the standard model of particles can contain more than one sterile neutrino states. Generally, existence of more sterile states leads to better, or at least equally good, fit to the short baseline anomalous data due to the larger number of parameters and interferences which create features in the oscillation pattern. However, for experiments like IceCube, where the sterile states distort the oscillation pattern of high energy atmospheric neutrinos through parametric and MSW resonances, addition of more sterile states leads to a more intense effect. Although the limits on one additional sterile neutrino state by IceCube data have been studied in the literature, bounds on the models with more sterile states are lacking. We analyze the one-year data set of atmospheric neutrinos collected by IceCube during the 2011–2012 and derive the limits on the parameter space of (3+2) scenario with two sterile neutrino states, taking into account the relevant systematic and statistical uncertainties and atmospheric neutrino flux variants. To facilitate the joint analysis of IceCube and short baseline data, we provide the table of χ
2 values from IceCube's data analysis as function of the parameters.
Some regularity properties of scattering data for the derivative nonlinear Schrödinger equation
Authors: Weng Weifang , Yan Zhenya
Published: November 2024

In this paper, we present some properties of scattering data for the derivative nonlinear Schrödinger equation in

H

s

(
R
)
(
s
≥

1

2

)

starting from the Lax pair. We show that the reciprocal of the transmission coefficient can be expressed as the sum of some iterative integrals, and its logarithm can be written as the sum of some connected iterative integrals. We provide the asymptotic properties of the first few iterative integrals of the reciprocal of the transmission coefficient. Moreover, we provide some regularity properties of the reciprocal of the transmission coefficient related to scattering data in

H

s

(
R
)

.
A test of measurement results with increased sensitivity to inconsistency
Authors: Willink R
Published: November 2024

This paper demonstrates that the chi-square test of consistency of a set of measurement results is improved upon when each measured value is compared with the weighted mean of all the other measured values, not the overall weighted mean. The corresponding test is a Monte Carlo test, where the null distribution for the new test statistic is obtained by simulation. Basing the procedure on the measurement results with smaller uncertainties would give further improvement.