bluuebunny/crossref_metadata_2025 huggingface dataset:
Visualization of the flow behind a backward-facing step using a schlieren technique and tetrafluoroethane
Authors: Itsariyapinyo Pititat
Published: November 2022

This paper explores the possibility of visualizing the low-speed, near-wall flow using a schlieren imaging technique. In this investigation, wind tunnel testing is conducted on a backward-facing step at step Reynolds numbers of 2940, 5140, and 6120. Tetrafluoroethane is injected through a rectangular slot mounted flush to the wind tunnel floor and is introduced to the downstream region of the step as refractive tracers. The visualization acquired at the midsection suggests that the mass flux of tetrafluoroethane should be approximately 5%–10% lower than that of the freestream air to ensure that the injection is less intrusive to the flow field while still achieving the visibility required to characterize the flow field. For long-exposure photography, the reattachment length or the length scale behind the step can be estimated when the exposure time of a camera is 3.2–12 times longer than the timescale of vortex roll-up. For high-speed photography, the sequence of vortex shedding can be adequately visualized when the frame rate of a camera is at least four times higher than the vortex shedding frequency.
Selective area heteroepitaxy of InAs nanostructures on nanopillar-patterned GaAs(111)A
Authors: Riedl Thomas , Kunnathully Vinay S. , Verma Akshay K. , Langer Timo , Reuter Dirk , Büker Björn , Hütten Andreas , Lindner Jörg K. N.
Published: November 2022

A process sequence enabling the large-area fabrication of nanopillar-patterned semiconductor templates for selective-area heteroepitaxy is developed. Herein, the nanopillar tops surrounded by a SiNx mask film serve as nanoscale growth areas. The molecular beam epitaxial growth of InAs on such patterned GaAs(111)A templates is investigated by means of electron microscopy. It is found that defect-free nanoscale InAs islands grow selectively on the nanopillar tops at a substrate temperature of 425 °C. High-angle annular dark-field scanning transmission electron microscopy imaging reveals that for a growth temperature of 400 °C, the InAs islands show a tendency to form wurtzite phase arms extending along the lateral ⟨112¯⟩ directions from the central zinc blende region of the islands. This is ascribed to a temporary self-catalyzed vapor–liquid–solid growth on {111¯} B facets, which leads to a kinetically induced preference for the nucleation of the wurtzite phase driven by the local, instantaneous V/III ratio, and to a concomitant reduction of surface energy of the nanoscale diameter arms.
Photoluminescence from InSb1−xBix alloys at extended wavelengths on InSb
Authors: White R. C. , Nordin L. J. , Muhowski A. J. , Wasserman D. , Bank S. R.
Published: November 2022

The incorporation of dilute concentrations of bismuth into traditional III–V alloys produces significant reductions in bandgap energy presenting unique opportunities in strain and bandgap engineering. However, the disparity between the ideal growth conditions for the host matrix and those required for substitutional bismuth incorporation has caused the material quality of these III–V–Bi alloys to lag behind that of conventional III–V semiconductors. InSb1−xBix, while experimentally underexplored, is a promising candidate for high-quality III–V–Bi alloys due to the relatively similar ideal growth temperatures for InSb and III–Bi materials. By identifying a highly kinetically limited growth regime, we demonstrate the growth of high-quality InSb1−xBix by molecular beam epitaxy. X-ray diffraction and Rutherford backscattering spectrometry (RBS) measurements of the alloy's bismuth concentration, coupled with smooth surface morphologies as measured by atomic force microscopy, suggest unity-sticking bismuth incorporation for a range of bismuth concentrations from 0.8% to 1.5% as measured by RBS. In addition, the first photoluminescence was observed from InSb1−xBix and demonstrated wavelength extension up to 7.6 μm at 230 K, with a bismuth-induced bandgap reduction of ∼29 meV/% Bi. Furthermore, we report the temperature dependence of the bandgap of InSb1−xBix and observed behavior consistent with that of a traditional III–V alloy. The results presented highlight the potential of InSb1−xBix as an alternative emerging candidate for accessing the longwave-infrared.
Growth of fiberform nanostructures on metal surfaces by helium plasma irradiation
Authors: Kajita Shin , Ito Atsushi M. , Ibano Kenzo
Published: November 2022

Helium plasma irradiation to various metals leads to peculiar morphology changes as forming fiberform nanostructures called fuzz when a certain set of conditions is satisfied. In this Tutorial, we overview experimental observations about the fuzz growth process, conditions, growth rate, etc. on tungsten (W), and fuzz growth observed on other various metals. The fuzz growth mechanism, open questions about fuzz growth, and current understandings on these issues are discussed based on simulation and theoretical works. Several applications (gas sensors and photocatalytic application) with fuzz are shown. We hope that this Tutorial will help new researchers in this field to perform experiments and simulations to reveal new perspectives of fuzz.
Tunneling injection to trap-limited space-charge conduction for metal-insulator junction
Authors: Chua Cherq , Ang Yee Sin , Ang Lay Kee
Published: November 2022

For a biased trap-filled insulator, the current transport is governed by the physics of charge injection from the metallic electrode and also the trap-limited space-charge conduction in the insulator. With a Schottky barrier at the interface of the metal-insulator junction, charge tunneling injection from a metal into the trap-filled insulator is different from an Ohmic contact. At sufficiently large amount of charge injection at high voltages, the charge transport becomes the trap-limited space-charge conduction. In this paper, we develop a consistent model to calculate the correct IV characteristics up to a breakdown field strength of 1 V/nm. Using this model, we analyze the transport characteristic of three different metal-insulator junctions (ITO/PPV, Al/h-BN, and Al/ZrO2) and identify the conduction mechanisms over a wide range of the applied voltage, insulator's thickness, and properties of the traps. Our findings report the interplay between various transport mechanisms, which is useful to characterize the correct current transport for novel insulators such as organic semiconductors, 2D insulators, and metal-oxide electronics.
Unsteady disturbances in a swept wing boundary layer due to plasma forcing
Authors: Peng K. , Avallone F. , Kotsonis M.
Published: November 2022

This work investigates the response of a transitional boundary layer to spanwise-invariant dielectric barrier discharge plasma actuator (PA) forcing on a 45° swept wing at a chord Reynolds number of 2.17×106. Two important parameters of the PA operation are scrutinized, namely, the forcing frequency and the streamwise location of forcing. An array of passive discrete roughness elements is installed near the leading edge to promote and condition a set of critical stationary crossflow (CF) instability modes. Numerical solutions of the boundary layer equations and linear stability theory are used in combination with the experimental pressure distribution to provide predictions of critical stationary and traveling CF instabilities. The laminar–turbulent transition front is visualized and quantified by means of infrared thermography. Measurements of velocity fields are performed using hotwire anemometry scans at specific chordwise locations. The results demonstrate the inherent introduction of unsteady velocity disturbances by the plasma forcing. It is shown that, depending on actuator frequency and location, these disturbances can evolve into typical CF instabilities. Positive traveling low-frequency type III modes are generally amplified by PA in all tested cases, while the occurrence of negative traveling high-frequency type I secondary modes is favored when PA is operating at high frequency and at relatively downstream locations, with respect to the leading edge.
Repeatable room temperature negative differential resistance in AlN/GaN resonant tunneling diodes grown on silicon
Authors: Zhang Baoqing , Yang Liuyun , Wang Ding , Quach Patrick , Sheng Shanshan , Li Duo , Wang Tao , Sheng Bowen , Li Tai , Yang Jiajia , Yuan Ye , Shen Bo , Wang Xinqiang
Published: November 2022

We report repeatable AlN/GaN resonant tunneling diodes (RTDs) grown on a silicon substrate by plasma-assisted molecular-beam epitaxy. The RTDs exhibit stable negative differential resistance without hysteresis at room temperature, where no degradation is observed even after 500 continuous bidirectional sweeps. The peak-to-valley current ratio is 1.36, and the peak current density is 24.38 kA/cm2. When the temperature is changed from 77 to 475 K, the peak current remains almost unchanged and the valley current increases gradually, resulting in a reduced peak-to-valley current ratio from 1.59 to 1.07. Our work softens the material quality constraints on realizing the room-temperature repeatable negative differential resistance and paves the way to low-cost III-nitride-based monolithic and hybrid microwave integrated circuits on large-size silicon wafers.
The first-principles study of structural and electronic properties of two-dimensional SiC/GeC lateral polar heterostructures
Authors: Alharbi Safia Abdullah R. , Tasnim Kazi Jannatul , Yu Ming
Published: November 2022

Two-dimensional (2D) lateral polar heterostructures, constructed by seamlessly stitching 2D polar materials, exhibit unique properties triggered by the in-plane charge transfer between different elements in each domain. Our first-principles study of 2D SiC/GeC lateral polar heterostructures has unraveled their interesting characteristics. The local strain induced by a lattice mismatch leads to an artificial uniaxial strain along the interface. The synergistic effect of such uniaxial strain, the microstructure of interface, and the width of domains modulates the feature of the bandgap with an indirect bandgap nature in armchair lateral heterostructures and a direct bandgap nature in zigzag lateral heterostructures. The bandgap monotonically decreases with increasing the width of domains, showing its tunability. Furthermore, the valence band maximum is found to be mainly contributed from C-2p orbitals located at both GeC and SiC domains, and the conduction band minimum is mainly contributed from Ge-4p orbitals located at the GeC domain, implying that most excited electrons prefer to stay at the GeC domain of the SiC/GeC lateral polar heterostructures. Interestingly, a net charge transfer from the SiC domain to the GeC domain was found, resulting in a spontaneous lateral p–n junction, and there is a net charge redistribution at the interfacial region leading to a built-in electric field which is expected to reduce the carrier recombination losses, implying the promising application for visible light photocatalyst, photovoltaics, and water splitting to achieve clean and renewable energy.
Computer simulation of the early stages of self-assembly and thermal decomposition of ZIF-8
Authors: Balestra S. R. G. , Semino R.
Published: November 2022

We employ all-atom well-tempered metadynamics simulations to study the mechanistic details of both the early stages of nucleation and crystal decomposition for the benchmark metal–organic framework (MOF) ZIF-8. To do so, we developed and validated a force field that reliably models the modes of coordination bonds via a Morse potential functional form and employs cationic and anionic dummy atoms to capture coordination symmetry. We also explored a set of physically relevant collective variables and carefully selected an appropriate subset for our problem at hand. After a rapid increase of the Zn–N connectivity, we observe the evaporation of small clusters in favor of a few large clusters, which leads to the formation of an amorphous highly connected aggregate. Zn(MIm)42− and Zn(MIm)3− complexes are observed with lifetimes in the order of a few picoseconds, while larger structures, such as four-, five-, and six-membered rings, have substantially longer lifetimes of a few nanoseconds. The free ligands act as “templating agents” for the formation of sodalite cages. ZIF-8 crystal decomposition results in the formation of a vitreous phase. Our findings contribute to a fundamental understanding of MOF’s synthesis that paves the way to controlling synthesis products. Furthermore, our developed force field and methodology can be applied to model solution processes that require coordination bond reactivity for other ZIFs besides ZIF-8.
Hedgehog-interacting protein acts in the habenula to regulate nicotine intake
Authors: Caligiuri Stephanie P. B. , Howe William M. , Wills Lauren , Smith Alexander C. W. , Lei Ye , Bali Purva , Heyer Mary P. , Moen Janna K. , Ables Jessica L. , Elayouby Karim S. , Williams Maya , Fillinger Clementine , Oketokoun Zainab , Lehmann Vanessa E. , DiFeliceantonio Alexandra G. , Johnson Paul M. , Beaumont Kristin , Sebra Robert P. , Ibanez-Tallon Ines , Kenny Paul J.
Published: November 2022

Hedgehog-interacting protein (HHIP) sequesters Hedgehog ligands to repress Smoothened (SMO)-mediated recruitment of the GLI family of transcription factors. Allelic variation in HHIP confers risk of chronic obstructive pulmonary disease and other smoking-related lung diseases, but underlying mechanisms are unclear. Using single-cell and cell-type-specific translational profiling, we show that HHIP expression is highly enriched in medial habenula (MHb) neurons, particularly MHb cholinergic neurons that regulate aversive behavioral responses to nicotine. HHIP deficiency dysregulated the expression of genes involved in cholinergic signaling in the MHb and disrupted the function of nicotinic acetylcholine receptors (nAChRs) through a PTCH-1/cholesterol-dependent mechanism. Further, CRISPR/Cas9-mediated genomic cleavage of the
Hhip
gene in MHb neurons enhanced the motivational properties of nicotine in mice. These findings suggest that HHIP influences vulnerability to smoking-related lung diseases in part by regulating the actions of nicotine on habenular aversion circuits.
The highest-elevation frog provides insights into mechanisms and evolution of defenses against high UV radiation
Authors: Fu Ting-Ting , Sun Yan-Bo , Gao Wei , Long Cheng-Bo , Yang Chun-Hua , Yang Xin-Wang , Zhang Yi , Lan Xin-Qiang , Huang Song , Jin Jie-Qiong , Murphy Robert W. , Zhang Yun , Lai Ren , Hillis David M. , Zhang Ya-Ping , Che Jing
Published: November 2022

Defense against ultraviolet (UV) radiation exposure is essential for survival, especially in high-elevation species. Although some specific genes involved in UV response have been reported, the full view of UV defense mechanisms remains largely unexplored. Herein, we used integrated approaches to analyze UV responses in the highest-elevation frog,
Nanorana parkeri
. We show less damage and more efficient antioxidant activity in skin of this frog than those of its lower-elevation relatives after UV exposure. We also reveal genes related to UV defense and a corresponding temporal expression pattern in
N. parkeri
. Genomic and metabolomic analysis along with large-scale transcriptomic profiling revealed a time-dependent coordinated defense mechanism in
N. parkeri
. We also identified several microRNAs that play important regulatory roles, especially in decreasing the expression levels of cell cycle genes. Moreover, multiple defense genes (i.e.,
TYR
for melanogenesis) exhibit positive selection with function-enhancing substitutions. Thus, both expression shifts and gene mutations contribute to UV adaptation in
N. parkeri
. Our work demonstrates a genetic framework for evolution of UV defense in a natural environment.
El condicional en las lenguas romances de la Península Ibérica
Authors: Lara Bermejo Víctor
Published: November 2022

Abstracta

El condicional como tiempo verbal en las lenguas romances de la Península Ibérica se debate entre valores temporales y modales. En este artículo, pretendemos dar cuenta de su vigencia en la lengua vernácula de todas las áreas lingüísticas iberorromances y compararla con los usos que exhibía hace cien años. Para ello, hemos sacado datos de cinco corpus sociolingüísticos actuales así como delAtlas lingüístico de la Península Ibérica. Los resultados muestran una evolución drástica en el empleo del condicional, liderada por el español y el portugués, los cuales han convertido el condicional en una marca morfológica de evidencialidad. Frente a estos, el gallego y el catalán mantienen usos modales que no se relacionan con los evidenciales. Además, el análisis demuestra que el matiz temporal es ínfimo y a menudo inexistente en gran parte del ámbito peninsular, como ya sugerían los datos de hace cien años.
Transnational wisdom literature goes pop in translation
Authors: Washbourne Kelly
Published: November 2022

The genre of self-help often is nurtured – or hijacked – from highbrow literary traditions such as conduct literature and sacred texts. Translation is the mechanism whereby an ‘esotouristic’ or new-ageified text travels in ready consumability, a commercializing process that asserts forms that themselves are ideological, and dramatically shifts ‘mirrors for princes’ and works considered ‘high literature’ to works of mass marketability. The branding of yogic and Kabbalistic texts, and of authors Kahlil Gibran, Baltasar Gracián, Rumi, and Sun Tzu, is analyzed in this light. I object to the ‘timeless classic’ positioning of texts that deterritorializes, dehistoricizes, and deculturizes, and map these publications as forms of manipulation, especially exoticizing, genre shifting, radical recontextualizing, and allegorizing. The resulting hyper-acceptability of the distorted products for a self-helpified readership calls into question the translator’s complicity in appropriative, otherized cultural production.
Interface welding mechanism and strengthening principle during friction stir spot welding of ultra-high strength C–Mn–Si martensitic steel
Authors: Wang Xiaopei , Morisada Yoshiaki , Ushioda Kohsaku , Fujii Hidetoshi
Published: November 2022

Solid-state welding mechanism of ultra-high strength C–Mn–Si martensitic steel during friction stir spot welding (FSSW) was clarified and interface strengthening principle was revealed. We found that the generated oxides in the interface became spherical and dispersed, which was caused by selective oxidation due to the reduced oxygen partial pressure during high welding temperature. Then, these oxides were further refined and dispersed by severe material flow around the welding interface. Consequently, the refined and spherical (Mn, Si, Al)O amorphous oxides were formed. In addition, strong material flow introduced large drive force for grain boundary migration around the welding interface, which further facilitated the migration and dispersion of the generated (Mn, Si, Al)O oxides, giving rise to a high-strength welding interface.
A 3D-printed spiral actuator for focus adjustment in circumferential scanning endomicroscopy
Authors: Zöğ İsra Salaheldin , Gürcüoğlu Oğuz , Özdemir Özgür , Yelten Mustafa Berke , Ferhanoğlu Onur
Published: November 2022

In this study, we showcase the design, manufacturing, and characterization of the focus adjustment actuator for use in capsule endoscopy. The actuator has a spiral flexure, carrying a lens and multiple magnets at its center to facilitate focusing through electromagnetic actuation. The interplay between the spiral flexure length and the lens size is investigated for optimal performance. An external coil is utilized to drive the lens actuator with a low power (∼5 mW) to acquire data from targets placed at multiple depths, axially spanning a range of 5 mm. The proposed actuator was intended for use in a circumferentially scanning wireless capsule endoscopy to provide high-resolution imaging at multiple depth sections throughout the gastrointestinal tract. The proposed device, targeted for confocal imaging, comprises a laser source and a light detector, the 3D-printed focus adjusting actuator to address different layers, a prism integrated micro-motor for circumferential scanning. We showcase a proof of principle data acquisition from reflective targets placed at different depths, through utilizing a scanning micromotor in conjunction with the developed focus actuator. With further development, the proposed actuator can be adapted to clinical environment to perform optical biopsies.
Design and fabrication of non-resonant PZT MEMS micromirror with buried piezoresistors for closed loop position control
Authors: Vergara Andrea , Tsukamoto Takashiro , Fang Weileun , Tanaka Shuji
Published: November 2022

This paper reports on a 1D PZT micromirror integrated with buried piezoresistors for quasi-static feedback position control. The piezoresistors located along or below the PZT actuators could achieve the sensitivity as high as 3.1 mV/°, which was two orders of magnitude higher than the traditional ones located at the torsion springs (8.2 μV/°). This increased the signal-to-noise ratio by 2 orders of magnitude, which could enable the accurate position control. The response of the longitudinal sensors along the beams had a fast settling time less than 1 ms. The average position error was 0.975%, which was much better than that from the conventional shear stress sensor on the torsion bar of 3.1%.
Engineering and manipulating topological edge states in a tunable magnon chain
Authors: Li Bo , Li Shuai , Wang Yongsheng , Zhang Yanpeng , Li Feng
Published: November 2022

We propose an effective scheme for manipulating the topological edge states in a tunable magnon chain with yttrium iron garnet spheres. In this setup, the coupling interactions between two magnons are realized indirectly via a split-ring resonator. With these indirect magnon–magnon couplings, we design a finite dimer chain with the Su–Schrieffer–Heeger Hamiltonian, show that Rabi oscillations between the left and right edge modes may be observed in an even-numbered case. For comparison, the characteristic of the edge state in an odd-numbered case is different, and we find that topological pumping of the edge state can be achieved via an adiabatic passage protocol. More importantly, we theoretically demonstrate that both the Rabi dynamics and the adiabatic pumping protocol could be used for long-range quantum state transfer, but the adiabatic-pumping transfer is particularly robust against intensity noise. This work provides a promising platform for creating topological devices, which may further be applied in quantum information processing.
Automated classification of breast cancer histologic grade using multiphoton microscopy and generative adversarial networks
Authors: Xi Gangqin , Wang Qing , Zhan Huiling , Kang Deyong , Liu Yulan , Luo Tianyi , Xu Mingyu , Kong Qinglin , Zheng Liqin , Chen Guannan , Chen Jianxin , Zhuo Shuangmu
Published: November 2022

Histological grade is one of the most powerful prognostic factors for breast cancer and impacts treatment decisions. However, a label-free and automated classification system for histological grading of breast tumors has not yet been developed. In this study, we employed label-free multiphoton microscopy (MPM) to acquire subcellular-resolution images of unstained breast cancer tissues. Subsequently, a deep-learning algorithm based on the generative adversarial network (GAN) was introduced to learn a representation using only MPM images without the histological grade information. Furthermore, to obtain abundant image information and determine the detailed differences between MPM images of different grades, a multiple-feature discriminator network based on the GAN was leveraged to learn the multi-scale spatial features of MPM images through unlabeled data. The experimental results showed that the classification accuracies for tumors of grades 1, 2, and 3 were 92.4%, 88.6%, and 89.0%, respectively. Our results suggest that the fusion of multiphoton microscopy and the GAN-based deep learning algorithm can be used as a fast and powerful clinical tool for the computer-aided intelligent pathological diagnosis of breast cancer.
Ion dynamics in the magnetic nozzle of a waveguide ECR thruster via laser-induced fluorescence spectroscopy
Authors: Vinci Alfio E , Inchingolo Marco R , Mazouffre Stéphane , Navarro-Cavallé Jaume
Published: November 2022

Xenon ion velocity is mapped in the magnetic nozzle (MN) of a circular waveguide electron cyclotron resonance thruster operating at 5.8 GHz by means of laser-induced fluorescence spectroscopy in the near-infrared spectral range. An array of thruster operational parameters are explored to investigate the influence on the acceleration profile and terminal ion velocity. Owing to several mechanisms which broaden the measured spectra, e.g. Paschen-Back/Zeeman effect, inference of the most probable velocity along with the axial kinetic temperature requires full lineshape modeling, especially in the near-field plume and inside the source. Ions are effectively accelerated along the MN, reaching up to 12 000 m s−1 for the lowest neutral pressure tested. A relatively large axial kinetic temperature is observed, typically in the order of 5000 K, which can be attributed to an extended ionization region that overlaps with the acceleration region.
Two-atom-thin topological crystalline insulators lacking out of plane inversion symmetry
Authors: Barraza-Lopez Salvador , Naumis Gerardo G
Published: November 2022

A two-dimensional topological crystalline insulator (TCI) with a single unit cell (u.c.) thickness is demonstrated here. To that end, one first shows that tetragonal (C
4 in-plane) symmetry is not a necessary condition for the creation of zero-energy metallic surface states on TCI slabs of finite-thicknesses, because zero-energy states persist even as all the in-plane rotational symmetries—furnishing topological protection—are completely removed. In other words, zero-energy levels on the model are not due to (nor are they protected by) topology. Furthermore, effective two-fold energy degeneracies taking place at few discrete k-points away from zero energy in the bulk Hamiltonian—that are topologically protected—persist at the u.c. thickness limit. The chiral nature of the bulk TCI Hamiltonian permits creating a

2
×
2

square Hamiltonian, whose topological properties remarkably hold invariant at both the bulk and at the single u.c. thickness limits. The identical topological characterization for bulk and u.c.-thick phases is further guaranteed by a calculation involving Pfaffians. This way, a two-atom-thick TCI is deployed hereby, in a demonstration of a topological phase that holds both in the bulk, and in two dimensions.
Split Bregman algorithm based on adaptive parameter for planar array sensor imaging
Authors: Sun Yurong , Zhang Yuyan , Wen Yintang
Published: November 2022

Planar array capacitance imaging is a visualization imaging technique based on the edge effect of electric fields. However, there are ill-posed problem and soft-field effects in the imaging process, which results in unstable and susceptible imaging. To address this issue, the inverse solution of planar array capacitive imaging system is transformed into an optimization problem with the approximate solution of linear-squares. A new cost function with total variation sparse reconstruction model is presented, which considers the sparsity of regularization operator to improve the stability of the inversion process. The adaptive split Bregman iterative algorithm is proposed to solve the inverse optimization problem. The computation is simplified by splitting the complex optimization problem into simple subproblems. The results show that the algorithm can obtain stable model updates, and numerical experiments prove the effectiveness and reliability of the algorithm.
Phase separation enabled silver nano-array
Authors: Liu Tianchi , Chang Tzu-Lan , Zhou Xiaqing , Ruppel Scott , Liang Jun F
Published: November 2022

The surface-supported silver nanoparticles have been studied and applied in various applications. Many unique nanostructures have been introduced into this field to improve the functionalities of the surfaces depending on application purposes. We created featured silver nano-array surfaces by utilizing the solvent-mediated phase transition on the surface grafted with poly (acrylic) acids polymer chains and taking advantage of the low temperature of argon gas discharged plasma as a reducing agent. The applied solvents and grafted polymer chain densities affected the phase transition and thus determined the outcome of surface nano-array patterns. However, the total loaded silver ions on the surface affected silver nano-array structures at the sub-micron levels. The featured silver patterned surfaces made in the optimal conditions present a favorable surface-enhanced Raman spectroscopy enhancement as well as recyclability for detection re-usage. This novel method prepares tunable silver nanopatterned surfaces and provides a new approach to various potential applications.
Selective sensing properties and enhanced ferromagnetism in CrI3 monolayer via gas adsorption
Authors: Ai Wen , Hu Xiaohui , Yang Jian , Lu Chunhua , Sun Litao
Published: November 2022

Recent fabrication of chromium triiodide (CrI3) monolayers has raised potential prospects of developing two-dimensional (2D) ferromagnetic materials for spintronic device applications. The low Curie temperature has stimulated further interest for improving the ferromagnetic stability of CrI3 monolayer. Here, based on density functional theory calculations, we investigated the adsorption energy, charge transfer, electronic and magnetic properties of gases (CO, CO2, N2, NH3, NO, NO2, O2, and SO2) adsorption on the CrI3 monolayer. It is found that CrI3 is sensitive to the NH3, NO, and NO2 adsorption due to the high adsorption energy and large charge transfer. The electrical transport results show that the conductivity of CrI3 monolayer is significantly reduced with the adsorption of N-based gases, suggesting that CrI3 exhibits superior sensitivity and selectivity toward N-based gases. In addition, the ferromagnetic stability and Curie temperature (T
C) of CrI3 monolayer can be effectively enhanced by the adsorption of magnetic gases (NO, NO2, O2). This work not only demonstrates that CrI3 monolayer can be used as a promising candidate for gas sensing, but also brings further interest to tune the electronic and magnetic properties of 2D ferromagnetic materials via gas adsorption.
Linear Newman-Penrose charges as subleading BMS and dual BMS charges
Authors: Long George
Published: November 2022

In this paper, we further develop previous work on asymptotically flat spacetimes and extend subleading BMS and dual BMS charges in a large r expansion to all orders in r
−1. This forms a complete account of this prescription in relation to the previously discovered Newman-Penrose charges. We provide an explanation for the origin of the infinite tower of linear Newman-Penrose charges with regards to asymptotic symmetries and justify why these charges fail to be conserved at the non-linear level as well as failing to exhibit full supertranslation invariance even at the linear level.
Experimental mapping of the ozone distribution in a pulsed positive corona discharge to estimate the efficiency of ozone production
Authors: Wattieaux Gaëtan , Ferrer Valentin , Sarrette Jean-Philippe , Merbahi Nofel , Eichwald Olivier
Published: November 2022

The spatial and temporal evolution of the ozone density has been measured in a 1 cm electrode gap tip to plane positive pulsed corona discharge in air at atmospheric pressure with no gas flow. It was expected to observe a higher ozone density in the vicinity of the discharge gap but ozone has been found at a quasi uniform density level up to 10 cm from the electrode gap after only 30 s of ignition. Such a wide distribution of ozone in the reactor cell is attributed to strong turbulence mostly triggered by the ionic wind. The mapping of the ozone density associated to the power measurement led to the estimation of the ozone production yield in term of mass per electrical energy.
Mechanism of pyrite photoconductance under an 808 nm-laser irradiation: a photo-thermal synergism
Authors: Miao Xinyang , Li Yudong , Wu Zhicong , Wang Lijun , Liu Xuecong , Zhan Honglei , Zhao Kun
Published: November 2022

As an earth-abundant mineral semiconductor, pyrite absorbs and converts photons under solar radiation to produce electrons, which is considered one of the important basic energy forms newly discovered in nature, and the response mechanism of light radiation on semiconductor minerals remains to be further explained. Here in this study, we focus on the photoconductance mechanism of natural pyrite, that is, an optical and electrical phenomenon in which the conductivity of a semi-coke is enhanced by absorption of an 808 nm wavelength laser. On the one hand, the photon energy of the 808 nm laser is higher than the band gap of pyrite, thus it can excite photogenerated charge carriers. On the other hand, the thermal effect produced by pyrite after absorbing the light energy will also improve the electrical conductivity. By monitoring the relationship between photoconductance, temperature, and time under laser irradiation, a photo-thermal synergism can be observed and evaluated. We aim to provide a basis for the study of the basic physical properties of natural pyrite, which will help to describe its role in geological and biological evolution.
Observation of $\Omega(2012) \to \Xi(1530)\bar{K}$ and measurement of the effective couplings of $\Omega(2012)$ to $\Xi(1530)\bar{K}$ and $\Xi\bar{K}$
Authors: Shen Chengping
Published: November 2022

Using $\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$ data collected by the Belle detector, we discover a new resonant three-body decay $\Omega(2012)^-\to \Xi(1530)^0K^-\to\Xi^-\pi^+K^-$ with a significance of 5.2$\sigma$. The mass of the $\Omega(2012)^-$ is $(2012.5\pm0.7\pm0.5)$ MeV and its effective couplings to $\Xi(1530)\bar{K}$ and $\Xi\bar{K}$ are $(41.1\pm35.8\pm6.0)\times10^{-2}$ and $(1.7\pm0.3\pm0.3)\times10^{-2}$, where the first uncertainties are statistical and the second are systematic. The ratio of the branching fraction for the resonant three-body decay to that for the two-body decay to $\Xi\bar{K}$ is $0.97\pm0.24\pm0.07$ assuming isospin symmetry, consistent with the molecular model of the $\Omega(2012)$, which predicts comparable rates for $\Omega(2012)$ decay to $\Xi(1530)\bar{K}$ and $\Xi\bar{K}$. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.
High resolution, wide field optical imaging of macaque visual cortex with a curved detector
Authors: Racicot Isabelle , Muslimov Eduard , Chemla Sandrine , Blaize Kévin , Ferrari Marc , Chavane Frédéric
Published: November 2022

Objective. Cortical activity can be recorded using a variety of tools, ranging in scale from the single neuron (microscopic) to the whole brain (macroscopic). There is usually a trade-off between scale and resolution; optical imaging techniques, with their high spatio-temporal resolution and wide field of view, are best suited to study brain activity at the mesoscale. Optical imaging of cortical areas is however in practice limited by the curvature of the brain, which causes the image quality to deteriorate significantly away from the center of the image. Approach. To address this issue and harness the full potential of optical cortical imaging techniques, we developed a new wide-field optical imaging system adapted to the macaque brain. Our system is composed of a curved detector, an aspherical lens and a ring composed of light emitting diodes providing uniform illumination at wavelengths relevant for the different optical imaging methods, including intrinsic and fluorescence imaging. Main results. The system was characterized and compared with the standard macroscope used for cortical imaging, and a three-fold increase of the area in focus was measured as well as a four-fold increase in the evenness of the optical quality in vivo. Significance. This new instrument, which is to the best of our knowledge the first use of a curved detector for cortical imaging, should facilitate the observation of wide mesoscale phenomena such as dynamic propagating waves within and between cortical maps, which are otherwise difficult to observe due to technical limitations of the currently available recording tools.
Quasifibrations of graphs to find symmetries and reconstruct biological networks
Authors: Boldi Paolo , Leifer Ian , Makse Hernán A
Published: November 2022

A fibration of graphs is a homomorphism that is a local isomorphism of in-neighborhoods. Recently, it has been shown that graph fibrations are useful tools to uncover symmetries and cluster synchronization in biological networks ranging from gene, protein, and metabolic networks to the brain. However, the inherent incompleteness and disordered nature of biological data preclude the application of the definition of fibration as it is. As a consequence, also the currently known algorithms to identify fibrations fail in these domains. In this paper, we introduce and develop systematically the theory of quasifibrations which attempts to capture more realistic patterns of quasi-symmetry in such networks. We provide an algorithmic solution to the problem of finding quasifibrations in networks where the existence of missing links and variability across samples preclude the identification of perfect fibration symmetries. We test our algorithm against other strategies to repair missing links in incomplete networks using real connectome data and synthetic networks. Quasifibrations can be applied to reconstruct any incomplete network structure characterized by underlying symmetrical and almost symmetrical clusters. The most direct application of our algorithms is that of helping researchers to find hidden symmetries in unknown (or partially unknown) networks, especially (but not exclusively) of biological nature.
A pedestal looseness fault diagnosis method based on NA-MEMD
Authors: Ma Shengheng , Li Gang , Chen Changshan , Wang Xiao , Guo Xianguang , An Xueli
Published: November 2022

When pedestal looseness fault occurs, rotor system’s vibration signals have non-stationary modulation characteristics. And traditional resonance demodulation method is difficult to determine the filter parameters. According to the fact, a pedestal looseness fault determination strategy of rotor system by using NA-MEMD (Noise-Assisted MEMD) is proposed. We use NA-MEMD to disassemble vibration signal into several stationary components. Envelope demodulation strategy is utilized to analyze each component. The vibration signal’s fault message can be acquired through this way. The displayed strategy is utilized to analyze the simulated signal and pedestal looseness fault vibration signal. The comes about appear that the displayed strategy can successfully extricate vibration signal’s fault characteristics of pedestal looseness fault in rotating machinery.
Distribution Network Reactive Power Optimization Method Based on Filter Coordinated Quantum State Transfer Algorithm
Authors: Ji Chenyun , Zhu Xiaohan
Published: November 2022

To solve the problem of mixed integer nonlinear programming in dynamic reactive power optimization of distribution networks, a two-stage dynamic reactive power optimization model is used to reduce the size of the reactive power optimization calculation.The first stage is nonlinear planning, with the objective of minimizing the combined system network loss and node voltage offset. The second stage is a mixed-integer planning, with the objective of minimizing the incremental power system network loss on the basis of satisfying the constraints such as the number of equipment regulation throughout the day. In view of the fact that the conventional penalty function method to deal with the constraints will result in improper selection of penalty factors, an improved quantum state transfer algorithm with mixed filter technique is proposed. The algorithm adopts a two-population parallel search approach, and the individual adaptation degree and constraint violation degree are constituted as filter pairs as evaluation metrics to replace the penalty functions. Finally, the proposed algorithm, the traditional state transfer algorithm and Colony Algorithm are solved separately for the model using the IEEE 14 system as examples, and the correctness of the proposed model and algorithm is verified by comparing and analyzing the simulation results.
Layout planning method of automation terminal in rural distribution network
Authors: Wu Er Lei
Published: November 2022

In order to solve the problem of distribution terminal layout in rural distribution automation planning, a scientific planning method for distribution automation terminal layout including microgrid is proposed. Firstly, the principle of distribution automation terminal configuration is analyzed, and the reliability evaluation method of distribution network considering distribution automation is studied. On this basis, an optimization model with the goal of minimizing the sum of the investment cost, operating cost, abandonment cost and power failure cost of the distribution terminal is established, and the genetic algorithm is used to solve the optimization model, so as to determine the distribution network Layout planning of automation terminals. The result of the improved IEEE RBTS Bus6-F4 example show that the method can obtain reasonable distribution automation terminal layout result.
Research on online monitoring system of fusion transmission line based on multi-source data
Authors: Du Xingkai , Qu Wanjun , Yu Xin , Wang Di , Zhao Xia , Gao Yinghong , Du Jikuan , Yu Aoyang
Published: November 2022

With the rapid development of China’s national economy, the length of transmission lines is increasing steadily, and the operating status of high-voltage transmission lines is directly related to the operational safety and efficiency of the entire power grid, but the sensors of transmission lines can only monitor one type of fault, and the fault analysis has limitations, which makes it impossible to comprehensively judge the operating status of transmission lines. This paper designs a transmission line online monitoring system based on multi-source data fusion, which adopts the improved Kalman filter algorithm. The data collected by the front-end system is fused, analyzed and shared in real time through the edge computing fusion terminal, so as to achieve a comprehensive judgment on the operation of transmission lines and improve the safe and stable operation level of transmission lines.
Fault Location of Distribution Network Based on Multi-population Particle Swarm Optimization Algorithm
Authors: Lei Jiaxing , Guo Yaosong , Luo Dashi , Xu Zhongyuan , Wang Rui
Published: November 2022

Fault location of the distribution network is an important direction in the construction of distribution automation. For the problem of slow convergence of intelligent optimization algorithms and easy to fall into local optimality, the multi-population particle swarm optimization algorithm is proposed. The algorithm is compared with single population particle swarm algorithm on IEEE69 node model, it is proved that the new algorithm can find fault location faster. Then the effectiveness of the algorithm in a variety of distribution network fault location scenarios is verified, including single fault location and multiple fault location, and the algorithm can also accurately locate when the input information is distorted which shows good fault tolerance.
Analysis of Influence of Distributed Photovoltaic on 10kV Line Relay Protection
Authors: Guo Xirong
Published: November 2022

Photovoltaic power generation is the most significant way to utilize solar energy in the world today. Facing the severe fossil energy crisis and environmental crisis facing the world today, photovoltaic power generation has obvious advantages from the perspective of resource sustainability and environmental friendliness. The access of distributed photovoltaic power sources will change the power flow distribution in the distribution network. If the grid-connected load of photovoltaic access is light, the photovoltaic capacity is large. After the photovoltaic is connected, the distribution network will become a multi-source network, and the photovoltaic output will be large. During this period, the line is prone to reverse current flow, which increases the line voltage and affects the power quality of the distribution network. Thence, it is essential to consider adopting strategies to control the voltage of the distribution network to ensure the safe and steady operation of the distribution network.
Influence of convex spherical device on the local field distribution in the microwave reaction cavity
Authors: Zhong Runeng , Li Lin , Yao Bin , Xiang Tai
Published: November 2022

Uneven energy distribution and “hotspot” phenomenon are bottlenecks restricting the development of the microwave heating industry. The formation of high-intensity electric field aggregation areas can be effectively repressed by optimizing the reaction cavity structures. With a box-type microwave reaction cavity as the study object and a built-in convex spherical as the induction device, the influences of the structural parameters of different devices on the microwave local field distribution were analytically explored through the simulation technology, and a “hotspot” early warning method was proposed. This study provides a reference for inhibiting the “hotspot” phenomenon on microwave fields and optimally designing microwave reactors.
Multi-energy joint optimal scheduling mechanism based on cooperative game considering transmission section limitation
Authors: Jinping Shi , Hanbing Zhang , Qianyun Du , yumin Wang , Yi Qiu , Xia Pan
Published: November 2022

The construction of power grid infrastructure lags behind the growth rate of installed power capacity, which makes it difficult to deliver clean energy in some areas, and multiple clean energy sources seize power generation channels. Taking the power system in a certain area of Zhejiang Province as the research object, the day-ahead scheduling mechanism suitable for the joint optimization of multiple power sources under the limitation of transmission section is discussed, and an improved comprehensive power generation benefit evaluation system is established. Firstly, the coefficient matrix of objective function is defined, and a mixed linear integer programming model with variable objective function is established. Then, the transmission channel load rate and transmission power smoothness are defined as the social benefits of power generation in this area. Finally, the optimal cooperation strategy and unit output combination are determined by changing the objective function coefficient matrix. The analysis of an example shows that the comprehensive power generation benefit can be optimized by adopting the strategy of the big alliance cooperative game.