bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi-colour light emission from InGaN nanowires monolithically grown on Si substrate by MBE
Authors: Gridchin Vladislav O , Kotlyar Konstantin P , Reznik Rodion R , Dragunova Anna S , Kryzhanovskaya Natalia V , Lendyashova Vera V , Kirilenko Demid A , Soshnikov Ilya P , Shevchuk Dmitrii S , Cirlin George G 
Published: May 2021

Abstract
InGaN nanostructures are among the most promising candidates for visible solid-state lighting and renewable energy sources. To date, there is still a lack of information about the influence of the growth conditions on the physical properties of these nanostructures. Here, we extend the study of InGaN nanowires growth directly on Si substrates by plasma-assisted molecular beam epitaxy. The results of the study showed that under appropriate growth conditions a change in the growth temperature of just 10 °C leads to a significant change in the structural and optical properties of the nanowires. InGaN nanowires with the areas containing 4%–10% of In with increasing tendency towards the top are formed at the growth temperature of 665 °C, while at the growth temperatures range of 655 °C–660 °C the spontaneously core–shell NWs are typically presented. In the latter case, the In contents in the core and the shell are about an order of magnitude different (e.g. 35% and 4% for 655 °C, respectively). The photoluminescence study of the NWs demonstrates a shift in the spectra from blue to orange in accordance with an increase of In content. Based on these results, a novel approach to the monolithic growth of In
x
Ga1−x
N NWs with multi-colour light emission on Si substrates by setting a temperature gradient over the substrate surface is proposed.
Frictional characteristics of graphene layers with embedded nanopores
Authors: Tong Mingjie , Jiang Yan , Wang Liya , Wang Chengyuan , Tang Chun 
Published: May 2021

Abstract
Graphite possessing extraordinary frictional properties has been widely used as solid lubricants. Interesting frictional characteristics have been observed for pristine graphene layers, for defective graphene, the frictional signal shows richer behaviors such as those found in topological defective graphene and graphene step edges. Recently discovered nanoporous graphene represents a new category of defect in graphene and its impact on graphene frictional properties has not yet been explored. In this work, we perform molecular dynamics simulations on the frictional responses of nanoporous graphene layers when slid using a silicon tip. We show that the buried nanopore raises maximum friction signal amplitude while preserving the stick-slip character, the size of the nanopore plays a key role in determining the maximum frictional force. Negative friction is observed when the silicon tip scanned towards the center of the nanopore, this phenomenon originates from the asymmetrical variation of the in-plane strain and the out-of-plane deformation when indented by the silicon tip. Moreover, the layer dependent frictional character is examined for the buried graphene nanopores, showing that increasing graphene layers weakens the effect of nanopore on the frictional signal.
Supersymmetry with self-consistent Schrödinger–Poisson equations: finding partner potentials and breaking symmetry
Authors: Abouzaid Amine , Levi A F J 
Published: May 2021

Abstract
It is shown that isospectral Hamiltonians and partner potentials can be found for self-consistent solutions of the Schrödinger and Poisson equations in the presence of identical non-interacting electrons. Perturbation of these systems by an external electric field can be used to break symmetry and spectrally distinguish between states. For a given pair of partner potentials, symmetry may also be broken by a change of electron density or temperature.
Gravitational waves from type II axion-like curvaton model and its implication for NANOGrav result
Authors: Kawasaki Masahiro , Nakatsuka Hiromasa 
Published: May 2021

Abstract
The recent report of NANOGrav is gathering attention since its signal can be explained by a stochastic background of gravitational waves (GWs) with an abundance of ΩGW ∼ 10-9 at the reference frequency f ∼ 10-8.
The PBH formation scenario is one of the candidates for the NANOGrav signal, which can simultaneously explain the observed 30M☉ black holes in the binary merger events in LIGO-Virgo collaboration.
We focus on the type-II axion-like curvaton model of the PBH formation.
In the type II model, the complex field whose phase part is the axion rolls down from the origin of the potential.
It is found that type II model achieves the broad power spectrum of the density perturbations and can simultaneously explain the LIGO-Virgo events and the NANOGrav signal.
We also improve the treatment of the non-Gaussianity of perturbations in our model to accurately estimate the amplitude of the induced GWs.
Recent results from EDELWEISS Dark Matter searches
Authors: Gascon J. 
Published: May 2021

Abstract
The EDELWEISS collaboration is performing direct searches for light Dark Matter particles using cryogenic germanium detectors equipped with a charge and thermal signal readout. This versatile and highly performing technology opens new possibilities for searches for signals involving either electrons or nuclear recoils. This is attested to by results on Axion- Like Particles in the keV range, and by the attainment of the first sub-GeV spin-independent dark matter limit based on a germanium target. The search has been extended to Strongly Interacting Particles (SIMP) down to 45 MeV by exploiting the Migdal effect. New results on SIMPs with spin-dependent interactions will also be presented.
Dark Matter Search Results from DAMIC
Authors: Chavarria A.E. 
Published: May 2021

Abstract
We present the current status of DAMIC at SNOLAB: a search for low-mass dark matter (DM) particles with low-noise CCDs. A 40 g 7-CCD array started operation in February 2017 and DM search data was acquired throughout 2017–2019. We summarize recent results on the search for few-e
− ionization signals induced by electronic recoils from the scattering of DM particles with masses ˜MeVc
−2 or the absorption of hidden photons with masses 1–10 eV c
−2. We report on the status of the search for ionization signals greater than 15 e
− from recoiling silicon nuclei following the scattering of DM particles with masses ˜GeV c
−2.
Search for WIMP-129Xe inelastic scattering using particle identification in the XMASS experiment
Authors: Suzuki Takumi 
Published: May 2021

Abstract
The inelastic scattering of Weakly Interacting Massive Particles (WIMPs) and 129Xe nuclei was searched for in the XMASS experiment. When excited by the inelastic scattering, the nuclei emit 39.6 keV γ-ray. The exposure of the data was 327 kg × 800.0 days. To improve the sensitivity of the signal, the events were classified by their pulse shapes, which discriminates between γ-rays and β-rays. As no significant signal was found, the upper limits of the inelastic channel cross section at the 90% confidence level were set. For a 200 GeV/c
2 WIMP, the limit was 4.1 × 10−39 cm2. This is the most stringent limit of the SD WIMP-neutron interaction.
Search for charged excitations of dark matter by KamLAND-Zen experiment
Authors: Hosokawa Keishi 
Published: May 2021

Abstract
There are many scenarios in which dark matter is a part of a multiplet with an electrically charged state. If WIMP dark matter is accompanied by a charged state separated by a small mass difference, it can form stable bound states with nuclei. The region of observable energy deposition via this process of bound state formation is O(1˜10 MeV). KamLAND-Zen is a large scintillator detector designed for neutrino-less double-beta decay search. This detector is also useful to detect dark matter bound state formations with nuclei. The result from the KamLAND-Zen 400 dataset is reported.
Ten years of cosmic muons observation with Borexino
Authors: D’Angelo Davide , Agostini M. , Altenmüller K. , Appel S. , Atroshchenko V. , Bagdasarian Z. , Basilico D. , Bellini G. , Benziger J. , Bick D. , Bonfini G. , Bravo D. , Caccianiga B. , Calaprice F. , Caminata A. , Cappelli L. , Cavalcante P. , Cavanna F. , Chepurnov A. , Choi K. , D’Angelo D. , Davini S. , Derbin A. , Di Giacinto A. , Di Marcello V. , Ding X.F. , Di Ludovico A. , Di Noto L. , Drachnev I. , Fomenko K. , Formozov A. , Franco D. , Gabriele F. , Galbiati C. , Gschwender M. , Ghiano C. , Giammarchi M. , Goretti A. , Gromov M. , Guffanti D. , Hagner C. , Hungerford E. , Ianni Aldo , Ianni Andrea , Jany A. , Jeschke D. , Kumaran S. , Kobychev V. , Korga G. , Lachenmaier T. , Laubenstein M. , Litvinovich E. , Lombardi P. , Lomskaya I. , Ludhova L. , Lukyanchenko G. , Lukyanchenko L. , Machulin I. , Manuzio G. , Marcocci S. , Maricic J. , Martyn J. , Meroni E. , Meyer M. , Miramonti L. , Misiaszek M. , Muratova V. , Neumair B. , Nieslony M. , Oberauer L. , Orekhov V. , Ortica F. , Pallavicini M. , Papp L. , Penek O. , Pietrofaccia L. , Pilipenko N. , Pocar A. , Raikov G. , Ranalli M.T. , Ranucci G. , Razeto A. , Re A. , Redchuk M. , Romani A. , Rossi N. , Rottenanger S. , Schönert S. , Semenov D. , Skorokhvatov M. , Smirnov O. , Sotnikov A. , Suvorov Y. , Tartaglia R. , Testera G. , Thurn J. , Unzhakov E. , Vishneva A. , Vogelaar R.B. , von Feilitzsch F. , Wojcik M. , Wurm M. , Zaimidoroga O. , Zavatarelli S. , Zuber K. , Zuzel G. 
Published: May 2021

Abstract
The Borexino detector at Gran Sasso has now accumulated over ten years of continuous data which represent a magnificent opportunity to study the cosmic muon flux at a deep underground location. We present here a precision measurement of the flux and of the expected seasonal modulation. We present the correlation with the atmospheric temperature variations from global atmospheric models. We measure the correlation parameters and infer the kaon-to-pion ratio in the production of cosmic muons from high energy primaries. We also find evidence of a long term modulation that is not present in the atmospheric data and we investigate a possible positive correlation with the solar activity. Finally we observe a seasonal modulation of the production rate of cosmogenic neutrons that is in phase with the muon modulation but shows a surprisingly larger amplitude.
Prospects for THEIA: an advanced liquid scintillator neutrino experiment
Authors: Guffanti D 
Published: May 2021

Abstract
THEIA is a proposed large-scale neutrino experiment based on advanced liquid scintillator and readout by high-quantum efficiency and fast photosensors. In order to combine the advantages of water Cherenkov detectors (i.e. large mass, direction reconstruction and low cost) with the ones of liquid scintillator (high light yield, low threshold) THEIA will deploy a Water-based Liquid Scintillator, which is currently at the center of an active R&D program. This detector concept has the potential to pursue a broad physics program that is summarized in this contribution. As a long baseline experiment installed at Homestake, THEIA will be complementary to the forthcoming DUNE experiment for the determination of the neutrino mass hierarchy and of the CP phase. At the same time, the low energy threshold and efficient neutron tagging makes THEIA an excellent detector for solar and supernova neutrinos measurements as well as for the search of neutrinoless ββ-decay and of other rare phenomena.
Development of new trigger system for KamLAND2-Zen
Authors: Takeuchi Atsuto , Kawada Nanami 
Published: May 2021

Abstract
KamLAND2-Zen is the future plan for the existing KamLND-Zen experiment, which will search for neutrinoless double-beta decay. In this experiment, muon spallation products are expected to be the main background. Spallation backgrounds can be tagged by delayed coincidence with neutrons emitted in spallation. Therefore, it is important to detect neutrons with high efficiency. However, enhancement of light yield will increase after-pulses and fake triggers due to them resulting in DAQ deadtime and low detection efficiency of neutrons. To solve this problem, a new trigger scheme which uses simultaneous hit of neighboring PMTs was developed. According to a simulation performed with real PMT waveforms, this scheme is expected to improve neutron detection efficiency from 54% to 89%. Consequently 99% of 10C background events can be tagged.
Evaluation of position dependent performance of 3-inch PMTs for Multi-PMT development
Authors: Izumi N , Ishitsuka M , Kuze M , Nishimura Y , Quilain B 
Published: May 2021

Abstract
Hyper-Kamiokande detector is proposed as a next generation underground water Cherenkov detector in Japan, and is planned to be an order of magnitude bigger than its predecessor, Super-Kamiokande. In order to further improve the detector capabilities in both low and high energy sectors, the multi-PMT modules instrumented with multiple 3-inch PMTs are being developed, in addition to the improved high quantum efficiency 20-inch PMTs. We developed a moveable laser system that can illuminate different positions on the photocathode to measure the characterization of the 3-inch PMTs as a function of the position on the photocathode.
Status of JSNS2 - J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source
Authors: Rott Carsten 
Published: May 2021

Abstract
The JSNS2 experiment will search for neutrino oscillations with Δm2 ≃ 1 eV2 from

v
¯

μ

to

v
¯

e

, detected via the inverse beta decay (IBD) reaction

(

v
¯

e

+
p
→

e
+

+
n
)

and tagged via gammas from neutron capture on Gadolinium. A 3 GeV 1 MW proton beam incident on a mercury target at the Materials and Life Science Experimental Facility at J-PARC produces an intense neutrino flux from muon decay at rest

(

μ
+

→

e
+

+

v
¯

μ

+

v
e

)

. The first of two 50 tons liquid scintillator detectors is nearly completed and will be located at a distance of 24 m from the neutrino source. JSNS2 can directly test the LSND anomaly and is expected to start taking data in early 2020.
Study of the radon removal and detection for JUNO
Authors: Zhang Y.P , Guo C. , Liu J.C. , Zhang P. , Yang C.G. 
Published: May 2021

Abstract
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose underground experiment with primary physics goal the neutrino mass hierarchy determination. For the sake of suppressing the radioactivity from the surrounding rocks and tagging the cosmic muons, the central detector is surrounded by a water Cherenkov detector. Therefore, the strict requirements are put forward for intrinsic radioactivity in water, i.e., the radon concentration should be less than 0.2 Bq/m3. In order to monitor the radon concentration in water, a high sensitivity detector has been developed. The degassing membrane device and the micro-bubble generator were installed in the JUNO prototype water system to study the radon removal in water.
Research on Task Analysis Framework for Unconventional Sudden Decision-making Problems
Authors: Pengfei Peng , Linru Zhou , Li Gong 
Published: May 2021

Abstract
In view of the structural uncertainty, suddenness and unpredictability of the current unconventional sudden decision-making problems, the analysis of the unconventional sudden emergency decision-making task analysis proposes a task analysis from task description to scenario construction and task analysis plan optimization process. In the task analysis, the joint extraction model is used to extract the task entities and the relationship between the task entities in the decision-making problem; the scenario construction is used to supplement the task description and constraint conditions; the cyclic neural network is used to simulate the thinking of the decision maker to complete the task analysis plan optimization. This analysis method adds hidden information such as the environment and constraints in the analysis to the analysis process, which is conducive to improving the suitability of the task analysis plan, and has application and promotion value in the research of task analysis framework for unconventional sudden decision problems.
Multi-exposure image fusion based on recursive filter
Authors: Li Ting , Xie Kai , Li Tong , Yan Yubing , Huang Ling 
Published: May 2021

Abstract
Multi-exposure image fusion technology is to fuse images of the same scene with different exposures into a high-quality image that contains more scene information. This paper proposes a multi-exposure image fusion method based on a recursive filter. The method first calculates three characteristic indicators of the multi-exposure image sequence: image contrast, entropy, and exposure information. And use three characteristic indicators to estimate the initial image fusion. In order to obtain a more accurate weight map for image fusion, a recursive filter is used to refine the weight map. Finally, the weighted sum method is used to construct the fused image. The experimental results show that the fusion results obtained by the algorithm in this paper have high image clarity, better subjective visual fusion effects and objective performance indicators, and maintain a high computational efficiency.
Detecting Fake News With Machine Learning
Authors: Huang Jeffrey 
Published: May 2021

Abstract
Fake news is increasingly prevalent in our modern digital age. It ranges from misleading writing and disguised opinion pieces to pieces of satire. With the advent of social media and the growth of the internet in the 21st century, the creation, access, and spread of false information are rapidly increasing in volume. Widespread fake news can foster many problems, including misinformed public opinions and dangerous levels of political division. Current methods of tackling fake news revolve around manual reviews, fact-checking organizations, and black-listing unreliable sources. However, many of these tactics are easily exploited or ineffective. This paper applied machine learning on a Kaggle dataset to predict whether an article of news was real or fake. We applied three different classifiers, all yielding promising results.
How NLOS Signals affect GNSS relative positioning
Authors: Ye Xiaozhou , Ma Pengcheng , Liu Wenxiang , Wang Feixue 
Published: May 2021

Abstract
Owing to the existence of non-line-of-sight (NLOS) signals in global navigation satellite system (GNSS) challenged environment, the accuracy of GNSS relative positioning is seriously damaged. This paper demonstrates the effects of NLOS measurement error on GNSS relative positioning for short-baseline in both theory and field test. The results show that the effects of NLOS signal in both pseudorange and carrier phase make the ambiguity unable to be successfully fixed. In addition, we have found that after removing the labelled NLOS observations, the positioning accuracy can be significantly improved. The more the available LOS satellites, the more the robustness against NLOS satellites of the ambiguity resolution. This implies that GNSS Multi-Frequency Multi-System technology might improve the performance of GNSS relative positioning because there would be sufficient LOS signals after the NLOS signals are removed.
A Comparison of Single-Buffer and Double-Buffer Design in a Systolic Array Generator
Authors: Su Dongchu , Li Yong 
Published: May 2021

Abstract
In application fields such as face recognition and image recognition using deep learning, more convolution operations are required for the increasing amount of data. Therefore, the use of systolic array acceleration is becoming a key technology trend to accelerate the development of deep learning applications. In previous designs, most of the systolic array used single-buffer or double-buffer structures, but most of them did not compare the difference between the two in detail. This work designs and implements a three-level systolic array generator, which can be configured in single-buffer or double-buffer modes. We also program the generated systolic array accelerator on Nexys-Vedio FPGA to explore the performance and overhead of single-buffer and double-buffer structure modes. The results show that the throughput of the double-buffer structure is increased by nearly 3 × compared to the single-buffer structure while only brings an additional 28% power consumption and 25% area overhead under the SIMC 130nm technology. And compared with the previous work, the proposed systolic array generator reduces power consumption by 75% and area overhead by 34% with almost no loss in performance.
Investigation of monolayer and submonolayer films using X-ray photoelectron spectroscopy
Authors: Afanas’ev V P , Selyakov D N , Ridzel O Yu , Semenov-Shefov M A , Strukov A N 
Published: May 2021

Abstract
A method of layer thickness determination by X-ray photoelectron spectroscopy (XPS) is analyzed. Angle-resolved XPS spectra measured for three samples (gold films of different thicknesses located on top of silicon substrates) have been interpreted by the straight line approximation (SLA) model. Two configurations of films were considered: (i) a flat surface of a semi-infinite layer (substrate) is covered with a flat homogeneous layer, (ii) coating constitutes an island (cluster) structure. It is shown that the simplest model of an island coating makes it possible to qualitatively explain the effect of decreasing of the effective average coating thickness observed in the angle-resolved XPS experiments.
Ion irradiation effect (Ar+, E = 20-40 keV) on the mechanical properties and microstructure of aluminum V95 alloy
Authors: Gushchina N V , Makhin’ko F F , Ovchinnikov V V , Kaigorodova L I , Rasposienko D Yu , Vichuzhanin D I 
Published: May 2021

Abstract
The effect of 20-40 keV Ar+ ion irradiation on the mechanical properties and structural and phase state of hot-pressed profiles 6 mm thick made of an V95 alloy (Al-Zn-Mg-Cu system) after artificial aging has been studied. Irradiation (without causing heating) at fluences of 2∙1015 cm−2 and 1 ∙ 1016 cm−2 has been revealed to increase the relative elongation by 5%, without changing the strength characteristics. Electron microscopy examination has showed that irradiation has an effect on the state of the subgrain structure of the alloy. Irradiation at these fluences results in partial enlargement of the subgrain structure, and at higher fluence of 9.4∙ 1016 cm−2 it completely transforms the structure into coarse-grained one. At a distance of 150 μm from the irradiated surface, there is a slight increase in the subgrain size. The irradiation changes the morphology of Al6(Fe, Mn) intermetallic compounds in both the surface layer and the sample volume; namely, it sharply decreases the bulk density of lath-shaped intermetallic compounds and increases the density of the equiaxed ones. The degree of influence depend on the irradiation mode.
Microstructure of 1469 aluminum alloy after severe plastic deformation and ion irradiation
Authors: Gushchina N V , Ovchinnikov V V , Makhin’ko F F , Kaigorodova L I , Rasposienko D Yu 
Published: May 2021

Abstract
The effect of accelerated Ar+ ion beams with an energy of 10 keV on the microstructure and phase composition in 1469 alloy (Al-Cu-Li-Ag-Mg-Zr-Sc) initially subjected to severe plastic deformation (SPD) has been investigated by transmission electron microscopy. Irradiation has been found to result in the formation of a predominantly recrystallized nanocrystalline or fully recrystallized submicrocrystalline structure in the alloy, depending on the ion fluence. The irradiation liquidates the banded structure found in the alloy after SPD. Therefore, the structural elements (nanofragments, nanograins, submicrocrystals) are distributed uniformly in the volume of the irradiated sample. In addition, irradiation increases the volume fraction and the size bimodality of heterogeneously-generated T2-phase particles. The mechanism of nucleation and growth of excess phases has been proposed. The structure changes at a higher rate than it does during a long low-temperature annealing process, and structural changes are observed at a distance of ∼200 μm from the surface, which considerably exceeds the projected ion range (∼ 10 nm).