bluuebunny/crossref_metadata_2025 huggingface dataset:
Retro and specular Andreev reflections and valley-spin switching effect in graphene superconducting heterojunction
Authors: Li Wan-Ying , Wu Qing-Ping , Liu Zheng-Fang , Liu Fei-Fei , Xiao Xian-Bo
Published: April 2023

We investigated Andreev reflection of graphene-based normal/superconductor single and double junctions under the modulation of non-resonant circularly polarized light, staggered potential, and exchange field. In the graphene-based normal/superconductor single junction, we discovered that the circularly polarized light can adjust the bandgap of retro Andreev reflection and specular Andreev reflection. The exchange field can change the position of the transition point between retro Andreev reflection and specular Andreev reflection. In the graphene-based normal/superconductor/normal double junction, when the light field is modulated from left circularly polarized light to right circularly polarized light, the valley-spin switching effect between pure elastic co-tunneling and pure crossed Andreev reflection can be realized. By changing the exchange field, we achieved the conversion of non-local transport between pure elastic co-tunneling and pure crossed Andreev reflection. In addition, the energy location and range of crossed Andreev reflection and elastic co-tunneling can be controlled by the staggered potential and the exchange field. Our results suggest that the device can implement light and exchange field control of the Andreev reflection process and the spin-valley switch.
A hybrid boundary element method based model for wave interaction with submerged viscoelastic plates with an arbitrary bottom profile in frequency and time domain
Authors: Panduranga Kottala , Koley Santanu , Meylan Michael H.
Published: April 2023

This study investigates the scattering of surface ocean waves by a submerged viscoelastic plate placed over the variable bottom topography under the assumptions of linear theory. The solution is derived using the hybrid boundary element method. The boundary element method is faster and easier to use when compared to the most widely used analytical method, such as the eigenfunction expansion method. Moreover, the application of analytical methods is restricted to structures with regular geometries and flat sea bottom. However, the present solution technique works for the plate at any angle placed over the variable bottom topography. Furthermore, as a particular case, the scattering problem is analyzed when a rigid wall is placed downstream. Energy balance relations are derived to check the accuracy of the computed numerical results. The effect of sinusoidally varying bottom topography, damping parameter, and plate edge conditions on the Bragg resonance phenomenon is analyzed. Initially, the solutions are presented in the frequency domain using the hybrid boundary element method and then extended to the time domain using the Fourier transform. It is observed that when the edges of the submerged plate are fixed, the Bragg resonance occurs at lower values of the frequency parameter. However, the Bragg resonance occurs around the primary Bragg value when the plate has free edges. For certain incident wave frequencies, the viscoelastic plate that completely covers the undulating bed dissipates a greater amount of wave energy than when the plate only partially covers the seabed.
Generation of entangled-photons by a quantum dot cascade source in polarized cavities: Using cavity resonances to boost signals and preserve the entanglements
Authors: Nasiri Avanaki K. , Schatz George C.
Published: April 2023

Motivated by recent advances in the development of single photon emitters for quantum information sciences, here we design and formulate a quantum cascade model that describes cascade emission by a quantum dot (QD) in a cavity structure while preserving entanglement that stores information needed for single photon emission. The theoretical approach is based on a photonic structure that consists of two orthogonal cavities in which resonance with either the first or second of the two emitted photons is possible, leading to amplification and rerouting of the entangled light. The cavity–QD scheme uses a four-level cascade emitter that involves three levels for each polarization, leading to two spatially entangled photons for each polarization. By solving the Schrodinger equation, we identify the characteristic properties of the system, which can be used in conjunction with optimization techniques to achieve the “best” design relative to a set of prioritized criteria or constraints in our optical system. The theoretical investigations include an analysis of emission spectra in addition to the joint spectral density profile, and the results demonstrate the ability of the cavities to act as frequency filters for the photons that make up the entanglements and to modify entanglement properties. The results provide new opportunities for the experimental design and engineering of on-demand single photon sources.
The interplay of intra- and inter-layer interactions in bending rigidity of ultrathin 2D materials
Authors: Jiang Yingchun , Sridhar Srividhya , Liu Zihan , Wang Dingli , Zhou Huimin , Deng Jia , Chew Huck Beng , Ke Changhong
Published: April 2023

Continuum mechanics break down in bending stiffness calculations of mono- and few-layered two-dimensional (2D) van der Waals crystal sheets, because their layered atomistic structures are uniquely characterized by strong in-plane bonding coupled with weak interlayer interactions. Here, we elucidate how the bending rigidities of pristine mono- and few-layered molybdenum disulfide (MoS2), graphene, and hexagonal boron nitride (hBN) are governed by their structural geometry and intra- and inter-layer bonding interactions. Atomic force microscopy experiments on the self-folded conformations of these 2D materials on flat substrates show that the bending rigidity of MoS2 significantly exceeds those of graphene or hBN of comparable layers, despite its much lower tensile modulus. Even on a per-thickness basis, MoS2 is found to possess similar bending stiffness to hBN and is much stiffer than graphene. Density functional theory calculations suggest that this high bending rigidity of MoS2 is due to its large interlayer thickness and strong interlayer shear, which prevail over its weak in-plane bonding.
GHz adhesion dynamics of gold nanoparticles down to 40 nm in diameter
Authors: Cavigelli M. , Frimmer M. , Novotny L.
Published: April 2023

We investigate the acoustic vibrations of single gold nanoparticles on a glass substrate using time-resolved optical spectroscopy. Using a two-color pump–probe setup, we measure the transient change of a particle's reflectivity induced by an optical pump pulse. Our measurements identify both the axial mode, which corresponds to an oscillation of the distance between nanoparticle and substrate, and the particle's fundamental breathing mode, an oscillation of particle diameter. We investigate the scaling of the axial mode frequency with the radial mode frequency. Our analysis reveals that the scaling established for larger particles extends down to diameters of 40 nm. This finding strongly suggests that continuum models of contact mechanics hold for contact areas comprising only a few thousand atoms.
Effects of the 10B/11B isotopic substitution on shear relaxation in supercooled B2O3 liquid: A validation of the elastic model of viscous flow
Authors: Lovi Jacob M. , Sen Sabyasachi
Published: April 2023

The effects of atomic mass in terms of its zero-point vibrational energy, on molar volume, glass transition temperature Tg, and viscosity are studied in glassy and supercooled B2O3 liquids using boron isotope substitutions. The molar volume decreases and Tg and isothermal viscosity increase on the substitution of lighter 10B isotopes with the heavier 11B isotopes. These effects are argued to be a manifestation of the higher zero-point vibrational energy of the lighter isotope, which along with the anharmonicity of the potential well, results in a longer equilibrium inter-atomic distance and larger mean-square displacement with respect to that for the heavier isotope. The isotope effect on viscosity is increasingly enhanced as the temperature approaches Tg, which is shown to be consistent with the prediction of the elastic models of viscous flow and shear relaxation.
A new magnetic state selection method in high-performance optically detected compact cesium beam clocks
Authors: Chen Sifei , Liu Chen , Fan Lifeng , Li Chaojie , Li Yuanhao , Liu Chang , Wang Yanhui
Published: April 2023

We perform a new scheme of magnetic state selection in optically detected compact cesium beam clocks. Unlike the conventional method, we select atoms in the ground state |F = 4, mF ≠ −4⟩ by pointing the atomic collimator to the convex pole of the magnet realizing the two-wire magnetic field and detect atoms in |F = 3⟩ after interacting with the microwave field using a distributed feedback laser. The fluorescence background is greatly reduced as the inherent residual atoms |F = 4, mF = −4⟩ are avoided in this reversed scheme. The velocity distribution is narrowed, and the most probable velocity is decreased, since atomic trajectories are close to the weak-field region. We also investigate the relationship between the position of the atomic collimator and the distributions of the atomic beam, which is consistent with the Monte Carlo-based simulation model. By applying the reversed scheme and setting the deviated position of the collimator to 1.3 mm, the signal contrast is improved from 0.7 to 3, and the short-term frequency stability reaches 3.0 × 10−12 τ−1/2, nearly three times better than that of the high-performance version of Microsemi 5071A.
Activity of free-ranging dogs (Canis familiaris) in the Arcadia Valley, Queensland
Authors: Meek Paul D. , Ballard Guy , Marshall Darren , Marshall Lachlan , Smith Deane , Fleming Peter J. S.
Published: April 2023

GPS tracking collars were fitted to five free-ranging dogs (Canis familiaris) in the Arcadia Valley, Queensland to establish baseline movement data in this unique topographical landscape. Activity areas were generated with three home range methods using seasonally constrained fixes. Activity areas (Brownian Bridge and Utilisation Distribution) ranged from 2.9 to 689 km2 in this landscape, and revealed that topographical features previously thought to confine free-ranging dog movement were no barrier to habitat use.
Nitrate supply decreases fermentation and alleviates oxidative and ionic stress in nitrogen-fixing soybean exposed to saline waterlogging
Authors: Martins Tamires da Silva , Da-Silva Cristiane Jovelina , Shimoia Eduardo Pereira , Posso Douglas Antônio , Carvalho Ivan Ricardo , de Oliveira Ana Claudia Barneche , do Amarante Luciano
Published: April 2023

Nitrate (NO3−) nutrition is known to mitigate the damages caused by individual stresses of waterlogging and salinity. Here, we investigated the role of NO3− in soybean plants exposed to these stresses in combination. Nodulated soybean cultivated under greenhouse conditions and daily fertilised with a nutrient solution without nitrogen were subjected to the following treatments: Water, NO3−, NaCl, and NaCl + NO3−. Then, plants were exposed to waterlogging (6 days) and drainage (2 days). Compared to plants exposed to isolated stress, the saline waterlogging resulted in higher concentrations of H2O2, O2˙−, and lipid peroxidation at the whole-plant level, mainly during drainage. Furthermore, saline waterlogging increased fermentation and the concentrations of Na+ and K+ in roots and leaves both during waterlogging and drainage. NO3− supplementation led to augments in NO3− and NO levels, and stimulated nitrate reductase activity in both organs. In addition, NO3− nutrition alleviated oxidative stress and fermentation besides increasing the K+/Na+ ratio in plants exposed to saline waterlogging. In conclusion, NO3− supplementation is a useful strategy to help soybean plants overcome saline waterlogging stress. These findings are of high relevance for agriculture as soybean is an important commodity and has been cultivated in areas prone to saline waterlogging.
ABL kinases regulate the stabilization of HIF-1α and MYC through CPSF1
Authors: Mayro Benjamin , Hoj Jacob P. , Cerda-Smith Christian G. , Hutchinson Haley M. , Caminear Michael W. , Thrash Hannah L. , Winter Peter S. , Wardell Suzanne E. , McDonnell Donald P. , Wu Colleen , Wood Kris C. , Pendergast Ann Marie
Published: April 2023

The hypoxia-inducible factor 1-α (HIF-1α) enables cells to adapt and respond to hypoxia (Hx), and the activity of this transcription factor is regulated by several oncogenic signals and cellular stressors. While the pathways controlling normoxic degradation of HIF-1α are well understood, the mechanisms supporting the sustained stabilization and activity of HIF-1α under Hx are less clear. We report that ABL kinase activity protects HIF-1α from proteasomal degradation during Hx. Using a fluorescence-activated cell sorting (FACS)-based CRISPR/Cas9 screen, we identified HIF-1α as a substrate of the cleavage and polyadenylation specificity factor-1 (CPSF1), an E3-ligase which targets HIF-1α for degradation in the presence of an ABL kinase inhibitor in Hx. We show that ABL kinases phosphorylate and interact with CUL4A, a cullin ring ligase adaptor, and compete with CPSF1 for CUL4A binding, leading to increased HIF-1α protein levels. Further, we identified the MYC proto-oncogene protein as a second CPSF1 substrate and show that active ABL kinase protects MYC from CPSF1-mediated degradation. These studies uncover a role for CPSF1 in cancer pathobiology as an E3-ligase antagonizing the expression of the oncogenic transcription factors, HIF-1α and MYC.
Educating for inclusion: Diversity education programs can reduce prejudice toward outgroups in Israel
Authors: Weiss Chagai M. , Ran Shira , Halperin Eran
Published: April 2023

Intergroup prejudice is pervasive in many contexts worldwide, leading to discrimination and conflict. Existing research suggests that prejudice is acquired at an early age and that durably improving intergroup relations is extremely challenging, often requiring intense interventions. Building on existing research in social psychology and inspired by the Israeli TV series “You Can’t Ask That,” which depicts charismatic children from minority groups broaching sensitive topics at the core of intergroup relations, we develop a month-long diversity education program. Our program exposed students to the TV series and facilitated follow-up classroom discussions in which students constructively addressed various sensitive topics at the core of intergroup relations and learned about intergroup similarities, intragroup heterogeneity, and the value of taking others’ perspectives. Through two field experiments implemented in Israeli schools, we show that integrating our intervention into school curricula improved Jewish students’ attitudes toward minorities and increased some pro-diversity behavior up to 13 wk posttreatment. We further provide suggestive evidence that the intervention was effective by encouraging students to take their outgroups’ perspectives and address an element of scalability by delegating implementation responsibilities to classroom teachers in our second study. Our findings suggest that theoretically informed intensive education programs are a promising route to reducing prejudice at a young age.
Design strategies for the self-assembly of polyhedral shells
Authors: Pinto Diogo E. P. , Šulc Petr , Sciortino Francesco , Russo John
Published: April 2023

The control over the self-assembly of complex structures is a long-standing challenge of material science, especially at the colloidal scale, as the desired assembly pathway is often kinetically derailed by the formation of amorphous aggregates. Here, we investigate in detail the problem of the self-assembly of the three Archimedean shells with five contact points per vertex, i.e., the icosahedron, the snub cube, and the snub dodecahedron. We use patchy particles with five interaction sites (or patches) as model for the building blocks and recast the assembly problem as a Boolean satisfiability problem (SAT) for the patch–patch interactions. This allows us to find effective designs for all targets and to selectively suppress unwanted structures. By tuning the geometrical arrangement and the specific interactions of the patches, we demonstrate that lowering the symmetry of the building blocks reduces the number of competing structures, which in turn can considerably increase the yield of the target structure. These results cement SAT-assembly as an invaluable tool to solve inverse design problems.
Oxygen doping of cobalt-single-atom coordination enhances peroxymonosulfate activation and high-valent cobalt–oxo species formation
Authors: Wu Qian-Yuan , Yang Zheng-Wei , Wang Zhi-Wei , Wang Wen-Long
Published: April 2023

The high-valent cobalt–oxo species (Co(IV)=O) is being increasingly investigated for water purification because of its high redox potential, long half-life, and antiinterference properties. However, generation of Co(IV)=O is inefficient and unsustainable. Here, a cobalt-single-atom catalyst with N/O dual coordination was synthesized by O-doping engineering. The O-doped catalyst (Co-OCN) greatly activated peroxymonosulfate (PMS) and achieved a pollutant degradation kinetic constant of 73.12 min
−1
 g
−2
, which was 4.9 times higher than that of Co-CN (catalyst without O-doping) and higher than those of most reported single-atom catalytic PMS systems. Co-OCN/PMS realized Co(IV)=O dominant oxidation of pollutants by increasing the steady-state concentration of Co(IV)=O (1.03 × 10
−10
 M) by 5.9 times compared with Co-CN/PMS. A competitive kinetics calculation showed that the oxidation contribution of Co(IV)=O to micropollutant degradation was 97.5% during the Co-OCN/PMS process. Density functional theory calculations showed that O-doping influenced the charge density (increased the Bader charge transfer from 0.68 to 0.85 e), optimized the electron distribution of the Co center (increased the d-band center from −1.14 to −1.06 eV), enhanced the PMS adsorption energy from −2.46 to −3.03 eV, and lowered the energy barrier for generation of the key reaction intermediate (*O*H
2
O) during Co(IV)=O formation from 1.12 to 0.98 eV. The Co-OCN catalyst was fabricated on carbon felt for a flow-through device, which achieved continuous and efficient removal of micropollutants (degradation efficiency of >85% after 36 h operation). This study provides a new protocol for PMS activation and pollutant elimination through single-atom catalyst heteroatom-doping and high-valent metal–oxo formation during water purification.
Two structural switches in HIV-1 capsid regulate capsid curvature and host factor binding
Authors: Stacey James C. V. , Tan Aaron , Lu John M. , James Leo C. , Dick Robert A. , Briggs John A. G.
Published: April 2023

The mature HIV-1 capsid protects the viral genome and interacts with host proteins to travel from the cell periphery into the nucleus. To achieve this, the capsid protein, CA, constructs conical capsids from a lattice of hexamers and pentamers, and engages in and then relinquishes multiple interactions with cellular proteins in an orchestrated fashion. Cellular host factors including Nup153, CPSF6, and Sec24C engage the same pocket within CA hexamers. How CA assembles pentamers and hexamers of different curvatures, how CA oligomerization states or curvature might modulate host–protein interactions, and how binding of multiple cofactors to a single site is coordinated, all remain to be elucidated. Here, using single-particle cryoEM, we have determined the structure of the mature HIV-1 CA pentamer and hexamer from conical CA-IP
6
polyhedra to ~3 Å resolution. We also determined structures of hexamers in the context of multiple lattice curvatures and number of pentamer contacts. Comparison of these structures, bound or not to host protein peptides, revealed two structural switches within HIV-1 CA that modulate peptide binding according to CA lattice curvature and whether CA is hexameric or pentameric. These observations suggest that the conical HIV-1 capsid has different host–protein binding properties at different positions on its surface, which may facilitate cell entry and represent an evolutionary advantage of conical morphology.
Polygonal tessellations as predictive models of molecular monolayers
Authors: Regős Krisztina , Pawlak Rémy , Wang Xing , Meyer Ernst , Decurtins Silvio , Domokos Gábor , Novoselov Kostya S. , Liu Shi-Xia , Aschauer Ulrich
Published: April 2023

Molecular self-assembly plays a very important role in various aspects of technology as well as in biological systems. Governed by covalent, hydrogen or van der Waals interactions–self-assembly of alike molecules results in a large variety of complex patterns even in two dimensions (2D). Prediction of pattern formation for 2D molecular networks is extremely important, though very challenging, and so far, relied on computationally involved approaches such as density functional theory, classical molecular dynamics, Monte Carlo, or machine learning. Such methods, however, do not guarantee that all possible patterns will be considered and often rely on intuition. Here, we introduce a much simpler, though rigorous, hierarchical geometric model founded on the mean-field theory of 2D polygonal tessellations to predict extended network patterns based on molecular-level information. Based on graph theory, this approach yields pattern classification and pattern prediction within well-defined ranges. When applied to existing experimental data, our model provides a different view of self-assembled molecular patterns, leading to interesting predictions on admissible patterns and potential additional phases. While developed for hydrogen-bonded systems, an extension to covalently bonded graphene-derived materials or 3D structures such as fullerenes is possible, significantly opening the range of potential future applications.
B cell peripheral tolerance is promoted by cathepsin B protease
Authors: Chou Marissa Y. , Liu Dan , An Jinping , Xu Ying , Cyster Jason G.
Published: April 2023

B cells that bind soluble autoantigens receive chronic signaling via the B cell receptor (signal-1) in the absence of strong costimulatory signals (signal-2), and this leads to their elimination in peripheral tissues. The factors determining the extent of soluble autoantigen-binding B cell elimination are not fully understood. Here we demonstrate that the elimination of B cells chronically exposed to signal-1 is promoted by cathepsin B (Ctsb). Using hen egg lysozyme-specific (HEL-specific) immunoglobulin transgenic (MD4) B cells and mice harboring circulating HEL, we found improved survival and increased proliferation of HEL-binding B cells in Ctsb-deficient mice. Bone marrow chimera experiments established that both hematopoietic and nonhematopoietic sources of Ctsb were sufficient to promote peripheral B cell deletion. The depletion of CD4
+
T cells overcame the survival and growth advantage provided by Ctsb deficiency, as did blocking CD40L or removing CD40 from the chronically antigen-engaged B cells. Thus, we suggest that Ctsb acts extracellularly to reduce soluble autoantigen-binding B cell survival and that its actions restrain CD40L-dependent pro-survival effects. These findings identify a role for cell-extrinsic protease activity in establishing a peripheral self-tolerance checkpoint.
Cross-language influences in the processing of L2 multi-word expressions
Authors: Du Lingli , Siyanova-Chanturia Anna , Elgort Irina
Published: April 2023

The present chapter provides a state-of-the-art review of research into cross-language influences in the processing of multi-word expressions (MWEs) in a second language (L2). Two lines of research are considered: first, how L2 speakers process congruent MWEs versus L2-only MWEs; second, how L2 speakers process L1-only MWEs translated into the L2 compared with control phrases. Studies have shown that congruent MWEs generally have a processing advantage over L2-only MWEs in L2 speakers. In contrast, evidence is mixed with regard to whether or not translated L1-only MWEs exhibit a processing advantage over matched controls in L2 speakers, with facilitation so far observed for idioms, but not for other types of MWEs. We consider possible reasons for these mixed findings.
Comment dirais-je ? Que veux-tu ? Comment ça va ?
Authors: Tutin Agnès
Published: April 2023

Cet article porte sur les phrases préfabriquées propres aux interactions, dans lesquelles on observe une proportion importante de phrases interrogatives directes partielles commecomment dirais-je ?ouque veux-tu ?Après une présentation des principales structures syntaxiques et des principales fonctions de ces énoncés, nous examinons un échantillon de 10 phrases préfabriquées représentatives à partir des corpus oraux ORFEO-CEFC et ESLO2 et du corpus de romans PhraseoRom. Les résultats montrent que ces énoncés, divers dans leurs fonctions sémantiques et pragmatiques, ne se caractérisent pas de prime abord par le figement syntaxique, mais présentent dans l’ensemble une forte variation selon le registre et la modalité écrite ou orale (même si une variation à l’intérieur du même corpus est aussi perceptible). Cependant, certaines caractéristiques syntaxiques peuvent clairement être attribuées au statut préfabriqué dans le corpus oral (surreprésentation de l’inversion clitique, sous-représentation de la structurein situ).
Contextual graffiti and collective action frames at the Chilean social outbreak in 2019
Authors: Miranda Correa Melisa
Published: April 2023

Protest graffiti as visual activism provides a democratic space for demonstrators to articulate their narratives.
Nevertheless, the lack of leadership in the Chilean social outburst in 2019 becomes a challenge in outlining its impact. Thus,
this article provides an empirical case of political graffiti and explains how graffiti had a constitutive role in the social
movement and the immediate country’s political course after that. This paper proposes a transdisciplinary approach by combining
the analysis of graffiti as contextual texts (Pennycook, 2007) with ‘collective action
frames’ in studying political graffiti collected in a six-kilometre walk in Santiago, Chile. As a result, graffiti frameworks of
injustice denounce the state and police violence; frameworks of agency tend to organise protesters’ ideas for change, such as a
new constitution and the end of the current pension systems; and a strong sense of feminism conforms part of identity frames.
Exploring the status of filled pauses as pragmatic markers
Authors: Kosmala Loulou
Published: April 2023

The present study aims to explore the status of filled pauses as pragmatic markers by taking into account their
accompanying visual and gestural behavior. This aspect has not yet been widely explored, and the current study breaks new ground
by demonstrating that the analysis of gaze and gesture can shed substantial light on the pragmatic functions of filled pauses and
other pausing phenomena. Filled pauses (FPs) serve several pragmatic functions in speech, mainly planning but also turn-holding
and emphasis, and their use is also highly determined by register and setting. This research explores the different pragmatic
functions of FPs by analyzing their distribution in two different communication settings (conversation vs presentation setting),
combining a quantitative and a qualitative methodology, following Kosmala & Crible’s (2021) study on the same data. Particular
attention was paid to the co-occurring gestural activity of uh/ums and gaze behavior. Analyses show that the
pragmatic functions of FPs are also embodied in kinetic activities which differ according to the setting: more pragmatic and
referential ones were found during FPs in conversation than in the presentation setting, as well as more eye-contact, which
reflects their potential communicative role during interactional sequences.
The role of assessments in providing evasive answers in news interviews
Authors: Alroumi Abdulrahman , Lahlali El Mustapha
Published: April 2023

This paper examines the role of assessments in the design of interviewees’ answers in news interviews settings on
two Arabic networks. It employs a Conversation Analysis approach, in addition to quantitative analysis, to observe the most
recurrent positions for emerging assessments in interviewees’ answers. In addition, it examines the role of these assessments in
providing evasive answers to interviewers’ questions. The data consists of twenty-eight hours of recorded Arab news interviews
from four shows: Liqāʾ Xāṣ (Special Interview) and Bilā Ḥudūd (Without Bounds) on Aljazeera and
Nuqṭat Niḏ̣ām (Point of Order) and Muqābalah Xāṣah (Special Interview) on Al-Arabiya. The
findings reveal that assessments emerge in recurrent positions in interviewees’ answers and play a role in their design. Likewise,
they show the role of assessments in the design of evasive answers.
Effect of Ca content on microstructure and strength of as-extruded Mg-1.0Al-xCa alloy
Authors: He Zhaoxiang , Wang Sen , Ge Chuncheng , Yang Chubin , Yang Qingshan , Pan Hucheng , Qin Gaowu
Published: April 2023

In this work, the effects of Ca content and extrusion temperature on the microstructures and mechanical properties of Mg–1Al– xCa alloys have been investigated. For Mg–1.0Al–0.4Ca (wt-%, AX10) dilute alloy, decreasing extrusion temperature from 290°C to 260°C can inhibit the dynamic recrystallisation (DRX) process, and the yield strength (YS) is also increased from ∼266 ± 6 MPa to ∼309 ± 3 MPa. When increasing the Ca content, Mg–1.0Al–0.8Ca (wt-%, AX11), a higher density of the Al2Ca phase is dispersed at the grain boundaries, which can further restrict the growth of DRXed grains, only ∼1.0 µm. Consequently, the higher YS of ∼330 ± 5 MPa can be obtained. The relevant results can shed light on designing other high-strength and low-alloyed Mg wrought alloys.
PERK prevents rhodopsin degradation during retinitis pigmentosa by inhibiting IRE1-induced autophagy
Authors: Zhao Ning , Li Ning , Wang Tao
Published: April 2023

Chronic endoplasmic reticulum (ER) stress is the underlying cause of many degenerative diseases, including autosomal dominant retinitis pigmentosa (adRP). In adRP, mutant rhodopsins accumulate and cause ER stress. This destabilizes wild-type rhodopsin and triggers photoreceptor cell degeneration. To reveal the mechanisms by which these mutant rhodopsins exert their dominant-negative effects, we established an in vivo fluorescence reporter system to monitor mutant and wild-type rhodopsin in Drosophila. By performing a genome-wide genetic screen, we found that PERK signaling plays a key role in maintaining rhodopsin homeostasis by attenuating IRE1 activities. Degradation of wild-type rhodopsin is mediated by selective autophagy of ER, which is induced by uncontrolled IRE1/XBP1 signaling and insufficient proteasome activities. Moreover, upregulation of PERK signaling prevents autophagy and suppresses retinal degeneration in the adRP model. These findings establish a pathological role for autophagy in this neurodegenerative condition and indicate that promoting PERK activity could be used to treat ER stress-related neuropathies, including adRP.
Time-delay interferometry infinity for tilt-to-length noise estimation in LISA
Authors: Houba Niklas , Delchambre Simon , Hechenblaikner Gerald , Ziegler Tobias , Fichter Walter
Published: April 2023

The Laser Interferometer Space Antenna (LISA) mission is a space-borne observatory designed to detect and characterize gravitational wave sources inaccessible to ground-based detectors. The mission relies on laser interferometry to measure changes in space-time. In this context, non-avoidable noise sources within the LISA system, including tilt-to-length (TTL) coupling, reduce the detector’s resolution and complicate achieving the mission’s goals unless appropriate mitigation strategies are implemented. This paper applies time-delay interferometry infinity (TDI-

∞

) for TTL noise estimation in LISA and assesses its suitability from the perspective of system identification and calibration for the first time. The recently published TDI-

∞

concept indicates a different frequency response within the LISA measurement band compared to the standard methodology of TDI second-generation. Our main contribution is demonstrating the advantages of the TDI-

∞

algorithm for TTL noise calibration in space-borne interferometer constellations. Specifically, we show that this algorithm improves the estimation performance of TTL noise due to its frequency behavior while requiring less computation time. The reduction in computational effort afforded by the TDI-

∞

algorithm could accelerate the availability of calibrated TDI data for astrophysical analysis if required by the LISA science community. The improvement in estimation performance underscores the concept’s potential to enhance the detector’s sensitivity further.
Motion equations in a Kerr–Newman–de Sitter spacetime: some methods of integration and application to black holes shadowing in Scilab
Authors: Garnier Arthur
Published: April 2023

In this paper, we recall some basic facts about the Kerr–Newman–(anti) de Sitter (KNdS) spacetime and review several formulations and integration methods for the geodesic equation of a test particle in such a spacetime. In particular, we introduce some basic general symplectic integrators in the Hamiltonian formalism and we re-derive the separated motion equations using Carter’s method. After this theoretical background, we explain how to ray-trace a KNdS black hole, equipped with a thin accretion disk, using Scilab. We compare the accuracy and execution time of the previous methods, concluding that the Carter equations is the best one. Then, inspired by Hagihara, we apply Weierstrass’ elliptic functions to the non-rotating case, yielding a fairly fast shadowing program for such a spacetime. We provide some illustrations of the code, including a depiction of the effects of the cosmological constant on shadows and accretion disk, as well as a simulation of M87*.
Complex actions and causality violations: applications to Lorentzian quantum cosmology
Authors: Asante Seth K , Dittrich Bianca , Padua-Argüelles José
Published: April 2023

For the construction of the Lorentzian path integral for gravity one faces two main questions: firstly, what configurations to include, in particular whether to allow Lorentzian metrics that violate causality conditions. And secondly, how to evaluate a highly oscillatory path integral over unbounded domains. Relying on Picard–Lefschetz theory to address the second question for discrete Regge gravity, we will illustrate that it can also answer the first question. To this end we will define the Regge action for complexified variables and study its analytical continuation. Although there have been previously two different versions defined for the Lorentzian Regge action, we will show that the complex action is unique. More precisely, starting from the different definitions for the action one arrives at equivalent analytical extensions. The difference between the two Lorentzian versions is only realized along branch cuts which arise for a certain class of causality violating configurations. As an application we discuss the path integral describing a finite evolution step of the discretized de Sitter Universe. We will in particular consider an evolution from vanishing to finite scale factor, for which the path integral defines the no-boundary wave function.
Teleparallel Newton–Cartan gravity
Authors: Schwartz Philip K
Published: April 2023

We discuss a teleparallel version of Newton–Cartan gravity. This theory arises as a formal large-speed-of-light limit of the teleparallel equivalent of general relativity (TEGR). Thus, it provides a geometric formulation of the Newtonian limit of TEGR, similar to standard Newton–Cartan gravity being the Newtonian limit of general relativity. We show how by a certain gauge-fixing the standard formulation of Newtonian gravity can be recovered.
Pair production in the rainbow dS2 space
Authors: Sahin O , Salti M , Aydogdu O , Sogut K
Published: April 2023

The study is devoted to discuss the rate of pair production in a two-dimensional de Sitter (dS2) type manifold with the help of the rainbow gravity formalism and the method of the Bogoliubov transformations. After obtaining exact analytical solutions of the Dirac equation for the selected rainbow metric, we focus on the creation rate of massive spin-1/2 particles.
Using transfer-learning-based algorithms as data reduction strategies for volatile organic compounds classification using plasma spectroscopy
Authors: Zhang Xuan-Lun , Hsu Cheng-Che
Published: April 2023

This work presents the use of transfer-learning-based algorithms as data reduction strategies for the classification of volatile organic compounds (VOCs) using the optical emission spectroscopy of plasmas. The plasma used is generated with a home-made microplasma generation device (MGD) ignited in the mixtures of Ar and VOCs. The spectra are acquired from ten MGDs. The VOCs tested are methanol, ethanol, and isopropanol. VOCs are classified using a convolutional neural network. In addition, gradient-weighted class activation mapping is used as the explainable artificial intelligent technique. It ensures the model classification is based upon rational plasma physics by considering appropriate wavelengths. The VOC concentrations are then quantified using linear regression and an artificial neural network (ANN). The transfer learning-based algorithms tested are parameter transfer, REPTILE, and self-training. Spectral data from ten MGDs are grouped into source and target datasets. Ten MGDs are tested individually using a model that was trained on the other nine MGDs. The three MGDs with the lowest accuracy are chosen as the target dataset, while the other seven MGDs make up the source dataset. The original target dataset has 22 500 spectra and is further reduced to 12 600, 9000, 1800, 225, and 22 spectra to test the behavior of each algorithm. With 225 spectra used for training, the model trained with the random initial model shows an accuracy of 0.82. The models trained with parameter transfer and REPTILE have accuracies of 0.98 and 0.95, respectively. Finally, an ANN model is used to quantify the VOC concentration with an R
2 value of 0.9996. The results demonstrate the potential using transfer-learning-based algorithms as the data reduction strategies for classification of spectroscopic data.
Partial EEDF analysis and electron diagnostics of atmospheric-pressure argon and argon–helium DBD plasma
Authors: van der Gaag Thijs , Nezu Atsushi , Akatsuka Hiroshi
Published: April 2023

Partial arbitrary electron energy distribution function (EEDF) results for cold atmospheric-pressure plasma are reported. The EEDF is obtained using the visible bremsstrahlung inversion (VBI) method. This machine learning method requires only optical emission spectroscopy (OES) measurement and a momentum transfer cross section to determine a partial EEDF. Numerical EEDF of a pure-argon dielectric barrier discharge dataset with changing peak-to-peak voltage and a helium–argon discharge with changing mixture ratio are reported. Resemblance between the numerical EEDF and a two-temperature Maxwell distribution is observed and a simplified three-point numerical EEDF is obtained. The electron temperature and relative electron number density for the bulk and high-energy electron populations are measured. The bulk electron temperature was consistently 0.3 eV. For pure argon, the high-energy electron temperature decreased exponentially from 3 to 2.2 eV with increasing peak-to-peak voltage from 3.6 to 6.3 kV. For the helium–argon dataset, the high-energy electron temperature decreased linearly from 4.2 to 2.2 eV with increasing argon fraction 25%–100%. From an OES measurement, the arbitrary EEDF can be observed by utilization of the VBI method. Based on this numerical EEDF, appropriate assumptions can be applied to simplify the quantification of electron diagnostics.
Insights into electronic properties of strained two-dimensional semiconductors by out-of-plane bending
Authors: Chen Daohong , Wang Leixi , Lv Yawei , Liao Lei , Li Kenli , Jiang Changzhong
Published: April 2023

Strain engineering is an important strategy to modulate the electronic and optical properties of two-dimensional (2D) semiconductors. In experiments, an effective and feasible method to induce strains on 2D semiconductors is the out-of-plane bending. However, in contrast to the in-plane methods, it will generate a combined strain effect on 2D semiconductors, which deserves further explorations. In this work, we theoretically investigate the carrier transport-related electronic properties of arsenene, antimonene, phosphorene, and MoS2 under the out-of-plane bending. The bending effect can be disassembled into the in-plane and out-of-plane rolling strains. We find that the rolling always degrades the transport performance, while the in-plane strain could boost carrier mobilities by restraining the intervalley scattering. In other words, pursuing the maximum in-plane strain at the expense of minimum rolling should be the primary strategy to promote transports in 2D semiconductors through bending. Electrons in 2D semiconductors usually suffer from the serious intervalley scattering caused by optical phonons. The in-plane strain can break the crystal symmetry and separate nonequivalent energy valleys at band edges energetically, confining carrier transports at the Brillouin zone Γ point and eliminating the intervalley scattering. Investigation results show that the arsenene and antimonene are suitable for the bending technology, because of their small layer thicknesses which can relieve the rolling burden. Their electron and hole mobilities can be doubled simultaneously, compared with their unstrained 2D structures. From this study, the rules for the out-of-plane bending technology towards promoting transport abilities in 2D semiconductors are obtained.
Stretching effects on non-adiabatic electron dynamic behavior in poly(dG)-poly(dC) DNA upon the proton irradiation
Authors: Hu Zhihua , Deng Zun-Yi , Feng Hong-Jian
Published: April 2023

The electronic excitations caused by DNA when exposed to ion radiation is essential to DNA damage. In this paper, we investigated the energy deposition and electron excitation process of DNA with reasonable stretching range upon proton irradiation based on time-dependent density functional theory. Stretching changes the strength of hydrogen bonding between the DNA base pairs, which in turn affects the Coulomb interaction between the projectile and DNA. As a semi-flexible molecule, the way of energy deposition is weakly sensitive to the stretching rate of DNA. However, the increase of stretching rate causes the increase of charge density along the trajectory channel, sequentially resulting in an increase in proton resistance along the intruding channel. The Mulliken charge analysis indicates that the guanine base and guanine ribose are ionized, meanwhile the cytosine base and cytosine ribose are reduced at all stretching rates. In a few femtoseconds, there exists an electron flow passing through the guanine ribose, guanine, cytosine base and the cytosine ribose in turn. This electron flow increases electron transfer and DNA ionization, promoting the side chain damage of the DNA upon ion irradiation. Our results provide a theoretical insight for deciphering the physical mechanism of the early stage of the irradiation process, and are also of great significance for the study of particle beam cancer therapy in different biological tissues.
A novel abnormal data detection method based on dynamic adaptive local outlier factor for the vibration signals of rotating parts
Authors: Wang Haiming , Yang Shaopu , Liu Yongqiang , Li Qiang
Published: April 2023

Abnormal signals are inevitable in big data acquired from harsh industrial environments. Abnormal data detection is a crucial component of condition monitoring for rotating parts and is also the premise of data cleaning, compensation, and mining. To detect abnormal data segments of rolling bearings, this paper proposes a dynamic adaptive local outlier factor (DALOF) anomaly detection method. First, a data dynamic segmentation method based on sliding windows is designed to determine samples with variable lengths. Then, a time-domain feature extraction and fusion method based on principal component analysis is exploited to reduce the feature space discrepancy. To improve the accuracy of abnormal data detection, a data quality evaluation model is established to assess each data segment using DALOF. The validity of the proposed method is also verified by analyzing signals including missing data, random interference data, and drift data. Several other methods are respectively applied to identify these abnormal data to further demonstrate the benefits of the developed methodology.
Gray level residual field: an effective metric for pixelwise matching quality evaluation in local digital image correlation
Authors: Chi Yuxi , Zhao Wei , Pan Bing
Published: April 2023

Gray level residual (GLR), also known as correlation residual field or image difference, reflects the intensity differences between reference and deformed images. In finite element-based global digital image correlation (DIC), GLR field can be readily computed and has been successfully used for crack or damage detection. The computation of pixelwise GLR field requires dense displacement results, which can be obtained using mesh interpolation in global DIC. To obtain the GLR field in subset-based local DIC, in which results are obtained at discrete calculation points, a simple, efficient and practical computation method for GLR field is presented, which accounts for the influence of illumination variations unavoidably occurred in real DIC tests. The proposed method can be easily implemented on both central process unit and graphics process unit to realize real-time visualization. Experiments showed that the GLR field can quantitatively and intuitively evaluate the pixelwise matching quality and provide clearer and finer locations for new components or textures (e.g. cracks) presented in deformed images. By fully leveraging the pixelwise matching quality information provided by the GLR field, the capability and robustness of local DIC is expected to be further enhanced.
A 3D shape measurement method for high-reflective surface based on dual-view multi-intensity projection
Authors: Zhou Peng , Wang Hengyu , Wang Yao , Yao Chuanwei , Lin Bin
Published: April 2023

Phase shifting profilometry has been commonly used in three-dimensional shape measurement with the advantages of high-precision and non-contact. However, it is still challenging to measure high-reflective surface because image saturation will lead to absolute phase errors and reconstruction errors. In this paper, a dual-view multi-intensity projection method was proposed. Compared with the single-view method, the proposed method can reconstruct more points at each projection intensity especially for pixels around the specular angle and reduce the number of projections to reduce the time consumption. First, we established the dual-view structured light system consisting of two monocular systems that share the same projector. Subsequently, a dual-view saturated pixel judging method was proposed that enables the reconstruction results under two views to be combined without duplicate points. The multi-intensity projection method was adopted by reducing the input projection intensity step by step and reconstructing the remaining pixels around the specular angle. Finally, the reconstruction result can be obtained by stitching point clouds at each projection intensity. Experiments verified that the proposed method could improve the integrity of reconstructed point clouds and measurement efficiency.