bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybrid x-ray laser-plasma/laser-synchrotron facility for pump–probe studies of the extreme state of matter at NRC “Kurchatov Institute”
Authors: Potemkin Fedor V. , Mareev Evgeny I. , Garmatina Alena A. , Nazarov Maxim M. , Fomin Evgeniy A. , Stirin Alexander I. , Korchuganov Vladimir N. , Kvardakov Vladimir V. , Gordienko Viacheslav M. , Panchenko Vladislav Ya. , Kovalchuk Mikhail M. 
Published: May 2021

We developed a hybrid optical pump–x-ray probe facility based on the “Kurchatov’s synchrotron radiation source” and terawatt (TW) femtosecond laser. The bright x-ray photon source is based on either synchrotron radiation [up to 6 × 1014 photons/(s mm2 mrad2 0.1% bandwidth)] or laser-plasma generators (up to 108 photons/sr/pulse). The terawatt (TW) femtosecond laser pulse initiated phase transitions and a non-stationary “extreme” state of matter, while the delayed x-ray pulse acts as a probe. The synchronization between synchrotron radiation and laser pulses is achieved at 60.3 MHz using an intelligent field-programmable gate array-based phased locked loop. The timing jitter of the system is less than 30 ps. In laser-plasma sources, the x-ray and laser pulses are automatically synchronized because they are produced by using the same laser source (TW laser system). We have reached an x-ray yield of about 106 photons/sr/pulse with 6-mJ sub-ps laser pulses and using helium as a local gas medium. Under vacuum conditions, the laser energy increase up to 40 mJ leads to the enhancement of the x-ray yield of up to 108 photons/sr/pulse. The developed hybrid facility paves the way for a new class of time-resolved x-ray optical pump–probe experiments in the time interval from femtoseconds to microseconds and the energy spectrum from 3 to 30 keV.
Modeling proton interactions with magnetodynamic targets for electromagnetic field mapping
Authors: Zellner M. B. , Freeman M. S. , Neukirch L. P. , Uhlig W. C. , Berning P. R. , Doney R. L. , Phillips D. 
Published: May 2021

Proton radiography’s utilization of positively charged probing particles makes it susceptible to potential influences from electromagnetic forces generated at the target object. In this work, we investigate how the 800 MeV proton radiography system of Los Alamos National Laboratory would respond to such influences with intentions to develop proton radiography/deflectometry diagnostics capable of probing electromagnetic fields inside dynamically changing objects. To understand how the proton radiography system responds to object-generated electromagnetic fields, a series of simulations were performed, which map proton trajectories through the system. This leads to an understanding of how the radiographic images, normally dominated by multiple Coulomb scattering, would be modified. The simulations also highlight novel ways in which additional data could be collected to glean more information about electromagnetic influences within and around the target object.
Furan monomers and polymers from renewable plant biomass
Authors: Kashparova Vera P. , Chernysheva Daria V. , Klushin Victor A. , Andreeva Veronika E. , Kravchenko Oleg A. , Smirnova Nina V. 
Published: May 2021

Plant biomass is considered the main source of renewable carbon raw materials, which is a viable alternative to crude oil and natural gas and provides compounds with a low carbon footprint. The most promising direction for the conversion of biomass is the synthesis of 5-hydroxymethylfurfural, which is regarded as a platform chemical, the basis for the synthesis of valuable compounds, including monomers and polymers. The move of the polymer industry to renewable plant materials will contribute to solving global environmental problems and ensure the sustainability and environmental safety of plastics production. This review analyzes recent advances in the preparation of key C6-furan platform chemicals, such as 5-hydroxymethylfurfural, 2,5-furandicarboxylic acid, 2,5-diformylfuran, 2,5-bis(hydroxymethyl)furan, levulinic acid, and their use for the production of monomers and polymers based on renewable plant biomass. Production processes of widely known furan polyesters and polyamides, such as polyethylene-, polypropylene-, polybutylene furanoates, polyhexamethylene furanamide, are considered, as well as developments towards novel promising materials that are furan copolymers and polymer mixtures. For the first time, studies have been systematized aimed at converting liquid and solid wastes of the synthesis of platform chemicals, known as humins, into a range of value-added products, including organic compounds, porous carbon materials, thermosetting binders, and anticorrosive coatings that can replace similar materials based on fossil raw materials. Economic and environmental prospects and problems of production and consumption of furan polymers are considered.
The bibliography includes 275 references.
Isotropic FMR frequency enhancement in thin Py/FeMn bilayers under strong magnetic proximity effect
Authors: Polishchuk D M , Polek T I , Borynskyi V Yu , Kravets A F , Tovstolytkin A I , Korenivski V 
Published: May 2021

Abstract
Exchange biasing in ferromagnet/antiferromagnet bilayers is known to enhance the material’s ferromagnetic resonance frequency and make it strongly angle dependent due to the unidirectional anisotropy induced at the interface. We observe a ten-fold enhancement in frequency and angle-independent ferromagnetic resonance in bilayers of Py/FeMn with ultrathin FeMn, accompanied by a significantly enhanced magnetic moment. The observed isotropic frequency enhancement is consistent with rotatable rather than unidirectional magnetic anisotropy and the induced magnetic moment links this anisotropy with the ferromagnet-proximity effect. The estimated effective anisotropy field acting on the proximity-induced moment in ultrathin FeMn can be as high as 0.5 T at room temperature. Our results show the potential of the ferromagnetic proximity effect combined with the inherent exchange anisotropy in antiferromagnets for high-speed spintronic applications.
Caudal autotomy and regeneration of arc in a 3D gliding arc discharge plasma
Authors: Zhang Si-Yuan , Li Xiao-Song , Li He-Ping , Liu Jing-Lin , Zhu Ai-Min 
Published: May 2021

Abstract
To gain a better understanding of the mechanism governing arc dynamics in 3D gliding arc discharge (GAD) plasma, the spatio-temporal evolution of GAD was investigated in a reverse vortex flow by a novel reactor with ring (powered electrode, PE) and truncated cone (ground electrode, GE) electrodes. A newly underlying mechanism governing arc evolution in 3D GAD was gained with combination of flow field simulation, synchronous electrical characteristics, intensified charge coupled device images and high-speed photos. The spatio-temporal analysis indicates that, being different from the well-known ignition–gliding–extinction mechanism occurring in traditional GAD, the PE arc root glides continuously in the 3D GAD, but the GE arc root features jumps from the end of the gliding path to the beginning of the next one. By means of the jumping, the arc auto-sheds the caudal part of the arc and a new arc tail is simultaneously generated, rather than rebuilding a new arc channel back to the shortest electrode gap. With this special behavior of caudal autotomy and regeneration, the main part of the arc remains for each jump. This new insight improves the understanding of the discharge mechanism governing arc evolution in 3D GAD and provides a reference for optimization design of gliding arc plasma in a vortex flow.
Effects of annealing in air on microstructure and hardness of hydroxyapatite ceramics
Authors: Zhu Wenliang , Imamura Hayata , Marin Elia , Adachi Tetsuya , Miyamoto Nao , Yamamoto Toshiro , Kanamura Narisato , Pezzotti Giuseppe 
Published: May 2021

Abstract
In this study, microstructural variation of hydroxyapatite (HAp) ceramics upon thermal treatment in air at different temperatures was investigated by x-ray diffraction patterns, Raman and x-ray photoelectron spectroscopies. The results revealed a significant dependence of the microstructure of nonstoichiometric HAp on temperature, because of the competition between hydroxylation and different kinds of dehydroxylation at different temperatures, and a gradual increase in material hardness with annealing temperature because of structural reconstruction. In summary, a suitable thermal treatment can effectively tailor microstructure and defect contents, as well as chemical composition and mechanical hardness of HAp ceramics.
Photon-in/photon-out spectroscopy at the I20-scanning beamline at diamond light source
Authors: Hayama Shusaku , Boada Roberto , Chaboy Jesús , Birt Adrian , Duller Graham , Cahill Leo , Freeman Adam , Amboage Monica , Keenan Luke , Diaz-Moreno Sofia 
Published: May 2021

Abstract
A scanning multi-crystal x-ray emission spectrometer to perform photon-in/photon-out spectroscopy at the I20-Scanning beamline at Diamond Light Source is described. The instrument, equipped with three analyzer crystals, is based on a 1 m Rowland circle spectrometer operating in the vertical plane. The energy resolution of the spectrometer is of the order of 1 eV, having sufficient resolving power to overcome the core-hole lifetime broadening of most of the transition metals K-edges. Examples showing the capability of the beamline for performing high energy resolution fluorescence detection x-ray absorption spectroscopy (HERFD-XAS), non-resonant x-ray emission spectroscopy (XES) and resonant x-ray emission spectroscopy are presented. The comparison of the Zn and Mn K-edge HERFD–XANES of ZnO and MnO with ab initio calculations shows that the technique provides enhanced validation of the models by making subtle spectral features more visible.
Proposed extension of double-ended gauge block interferometers for measuring spheres
Authors: Schödel René , Fischedick Markus 
Published: May 2021

Abstract
Double-ended gauge block interferometers (DEI) are becoming more and more established. This paper suggests its extension for enabling interferometric measurement of diameter topographies of spheres as an alternative to the existing spherical Fizeau interferometers. The extension essentially consists in the addition of two lenses which are as similar as possible, which are arranged symmetrically around the sphere to be measured. The determination of the diameter topography from the interferometric measurements with inserted and without sphere in the extended DEI is derived and specific aspects are discussed. An adjustment strategy for the extended DEI is also suggested. In conclusion, the proposed extension appears to be a promising measurement tool, especially for measuring small spheres, as required for applications in coordinate metrology.
Optical form measurement employing a tiltable line scanning, low coherence interferometer for annular subaperture stitching interferometry
Authors: Schake Markus , Riebeling Jörg , Lehmann Peter , Ehret Gerd 
Published: May 2021

Abstract
This contribution presents experimental and simulation results of a tiltable line scanning low coherence interferometer applied for form measurement of spherical and aspherical objects with a diameter of up to 300 mm. The region of interest is sampled by multiple annular subapertures that are realigned employing stitching algorithms based on Cartesian- and Zernike polynomial fittings. The paper addresses common challenges in the reduction and modeling of displacement errors associated with the motion of the interferometric sensor between subaperture measurements and compares the topography deviations of the experimental results with those simulated by a Monte Carlo based model.
A novel nonenzymatic ascorbic acid electrochemical sensor based on gold nanoparticals-chicken egg white-copper phosphate-graphene oxide hybrid nanoflowers
Authors: Gao Jiaojiao , Liu Hui , Wu Kexin , Yan Jifeng , Tong Cheng 
Published: May 2021

Abstract
Au-CEW-Cu3(PO4)2-GO nanoflowers (HNFs), which were assembled of gold nanoparticals (Au NPs), chicken egg white (CEW), copper phosphate (Cu3(PO4)2) and graphene oxide (GO) together to form a flower-like organic/inorganic hybrid nanocomposite, were synthesized through a simple and gentle one-pot co-precipitation method. The prepared samples were well characterized by scanning electron microscope, transmission electron microscope, energy dispersive x-ray spectrometer, x-ray diffraction and Raman spectrometer. The prepared Au-CEW-Cu3(PO4)2-GO HNFs was used to modify glassy carbon electrode to fabricate an electrochemical sensor for detection of ascorbic acid (AA). The electrochemical test results show that the linear range of the developed sensor is 8–300 μM and the detection limit is 2.67 μM (S/N = 3). While this sensor displays high sensitivity of 6.01 × 10–3
μA μM−1 cm−2 and low detection potential of 35 mV due to the combination of the high conductivity of Au NPs, the larger specific surface area of GO and the intrinsic electrocatalytic activity of CEW-Cu3(PO4)2 HNFs. Moreover, the Au-CEW-Cu3(PO4)2-GO HNFs-based sensor was successfully developed for application in electrochemical detection of AA in vitamin C tablets.
Gold nanorods doping induced performance improvement of room temperature OTFT NO2 sensors
Authors: Hou Sihui , Shao Bingyao , Yu Xinge , Yu Junsheng 
Published: May 2021

Abstract
Solution-processed organic thin-film transistors (OTFTs) are regarded as the promising candidates for low-cost gas sensors due to their advantages of high throughput, large-area and sensitive to various gas analytes. Microstructure control of organic active layers in OTFTs is an effective route to improve the sensing performance. In this work, we report a simple method to modify the morphology of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) thin films via doping gold nanorods (Au NRs) for enhancing the performance of the corresponding OTFT sensors for nitrogen dioxide (NO2) detection. With the optimized doping ratio of Au nanorods, the TIPS-pentacene OTFT snesors not only exhibit a 3-fold increase in mobility, but also obtain a high sensitivity of 70% to 18 ppm NO2 with a detection limit of 270 ppb. The microstructures and morphologies of the modified TIPS-pentacene thin film characterized by atomic force microscopy and field scanning electron microscope. The experimental results indicate that the proper addition of Au NRs could effectively regulate the grain size of TIPS-pentacene, and therein control the density of grain boundaries during the crystallization, which is essential for the high-performance gas sensors.
Suppressing ion migration of CsPbBr
x
I3-x
nanocrystals by Nickel doping and the application in high-efficiency WLEDs
Authors: Yang Supeng , Zhu Hanwen , Xu Enze , Li Junchun , Yang Heming , Zhang Yan , Zhu Zhifeng , Jiang Yang 
Published: May 2021

Abstract
All inorganic perovskite nanocrystals CsPbX3(X = Cl, Br, I) are the great potential candidates for the application of high-performance light emitting diodes (LED) due to their high Photoluminescence Quantum Yield (PLQY), high defect tolerance, narrow full-width half-maximum and tunable wavelength of 410–700 nm. However, the application of red-emitting (630–650 nm) CsPbBr
x
I3-x
nanocrystals are perplexed by phase segregation due to the composition of mixed halides and the difference in halide ion mobility. Herein, we provide an effective strategy to suppressing the migration of Br/I ions through Ni2+ doping via a facile Hot-Injection method and the PLQY was improved as well. DFT calculations show that the introduction of Ni2+ causes a slight contraction of the host crystal structure, which improves the bond energy between Pb and halides and reduces the level of surface defects. Therefore, the phase stability is improved by Ni2+ doping because the phase segregation caused by ion migration in the mixed phase is effectively inhibited. Meanwhile, the non-radiative recombination in the exciton transition process is reduced and the PLQY is improved. What’s more, benefiting from the suppressed ion migration and enhanced PLQY, we combine the Ni2+-doped CsPbBr
x
I3-x
nanocrystals with different Br/I ratios and YAG: Ce3+ phosphors as color conversion layers to fabricate high efficiency WLED. When the ratio of Br/I is 9:11, WLED has a color coordinate of (0.3621, 0.3458), the color temperature of 4336 K and presents a high luminous efficiency of 113.20 lm W−1, color rendering index of 94.9 under the driving current of 20 mA and exhibits excellent stability, which shows great potential in the application of LED.
Radiation-induced magnetoresistance oscillations with massive Dirac fermions
Authors: Iñarrea Jesús , Platero Gloria 
Published: May 2021

Abstract
We report on a theoretical study on the rise of radiation-induced magnetoresistance oscillations in two-dimensional (2D) systems of massive Dirac fermions. We study the bilayer system of monolayer graphene and hexagonal boron nitride (h-BN/graphene) and the trilayer system of hexagonal boron nitride encapsulated graphene (h-BN/graphene/h-BN). We extend the radiation-driven electron orbit model that was previously devised to study the same oscillations in 2D systems of Schrödinger electrons (GaAs/AlGaAS heterostructure) to the case of massive Dirac fermions. In the simulations we obtain clear oscillations for radiation frequencies in the terahertz and far-infrared bands. We investigate also the power and temperatures dependence. For the former we obtain similar results as for Schrödinger electrons and predict the rise of zero resistance states. For the latter we obtain a similar qualitatively dependence but quantitatively different when increasing temperature. While in GaAs the oscillations are wiped out in a few degrees, interestingly enough, for massive Dirac fermions, we obtain observable oscillations for temperatures above 100 K and even at room temperature for the higher frequencies used in the simulations.
Electromagnetic instability analysis of functionally graded tapered nano-tweezers
Authors: Yaghoobi Majid , Koochi Ali 
Published: May 2021

Abstract
Increasing the application of electromechanical nano-tweezers for biological purposes results in new operating conditions such as an external magnetic field. This study deals with investigating the electromagnetic instability of nano-wire manufactured tweezers. To enhance the nano-tweezers’ operating range, a pair of functionally graded nano-wire-based tweezers with linearly varying diameter is considered. The impact of Lorentz forces due to external magnetic flux is simulated by developing Maxwell’s equation. The material distribution along the length of the nano-tweezers arms is modeled based on the power-law distribution. The size-dependent nonlinear constitutive equation of the system is extracted by employing the couple stress theory in combination with Hamilton’s principle. A finite element procedure is proposed to simulate the nano-system and investigate electromechanical instability behavior. The role of influential parameters, including the external magnetic field, the size dependency, material distribution, the Casimir force, and the geometry on the tweezering range and instability voltage of nano-tweezers, are investigated.
Dependence of upstream SOL density shoulder on divertor neutral pressure observed in L-mode and H-mode plasmas in the EAST superconducting tokamak
Authors: Yan N. , Chen L. , Xu G.S. , Wu X.Q. , Liu S.C. , Wang Y.F. , Meng L.Y. , Hu G.H. , Zhao N. , Lan H. , Naulin V. , Nielsen A.H. , Juul Rasmussen J. , Li K.D. , Wang L. , Yang Q.Q. , Li M.H. , Ye Y. , Ding R. , Tao Y.Q. , Qian Y.Z. , Hou J.L. , Liu X. , Liu J.B. 
Published: May 2021

Abstract
Upstream density profiles in the scrape-off layer (SOL) have been examined in low-confinement mode (L-mode) and high-confinement mode (H-mode) plasmas in the EAST superconducting tokamak. A weak density shoulder forms in the near SOL region in upper single-null configurations when the neutral pressure measured at the lower divertor exceeds a threshold value of 2 × 10−2 Pa in L-mode plasmas. When the neutral pressure is below this threshold, the weak density shoulder is absent and the sidebands of the lower hybrid waves associated with SOL parametric instabilities are reduced. Active detachment control with neon–deuterium seeding demonstrate that the weak density shoulder can form before the onset of the outer divertor detachment as long as the neutral pressure is above the threshold. Furthermore, no remarkable expansion of a shoulder is observed during divertor detachment, suggesting that divertor detachment is not a necessary condition for the formation or growth of a density shoulder. Through the increase in neutral pressure in the lower divertor by an order of magnitude, the weak shoulder was observed to expand into the far SOL and reach the leading edge of the limiter. The results in L-mode discharges identified the neutral pressure in the lower divertor as a primary factor for the formation of an SOL density shoulder in the upper single-null discharges. For the type-I ELMy H-mode plasmas, a similar density shoulder was detected during the inter-ELM phase when the neutral pressure in the lower divertor exceeded a threshold value of 4 × 10−2 Pa. On the other hand, the shoulder was absent when the divertor neutral pressure went below this threshold even though the plasma discharge was conducted with a higher core line-averaged density and divertor collisionality. This is consistent with the observations in L-mode plasmas. The neutral particle ionization of the working gas is thus believed to play a key role during the formation of the SOL density shoulder in the EAST tokamak.
Summary of the IAEA technical meeting on plasma disruptions and their mitigation
Authors: Bandyopadhyay Indranil , Barbarino Matteo , Bhattacharjee Amitava , Eidietis Nicholas , Huber Alexander , Isayama Akihiko , Kim Jayhyun , Konovalov Sergey , Lehnen Michael , Nardon Eric , Pautasso Gabriella , Rea Cristina , Sozzi Carlo , Villone Fabio , Zeng Long 
Published: May 2021

Abstract
This report summarizes the contributions presented at the IAEA technical meeting on plasma disruptions and their mitigation, held virtually, 20–23 July 2020. The meeting brought together more than 120 experts from nuclear fusion research sites worldwide to discuss experimental, theoretical and modelling work in the field of plasma disruptions with special emphasis on developing a solid basis for possible disruption mitigation strategies in ITER and next generation fusion devices. The main topics of the meeting were: (i) disruption consequences, including electromagnetic loads, heat loads, and runaway electrons; (ii) disruption prediction and avoidance, including machine learning and physics-based approaches, and control aspects; and (iii) disruption mitigation, including shattered pellet injection, alternative techniques and general aspects of disruption mitigation.
Elaboration of an App for calculations of dosimetric quantities aiming at radiological protection
Authors: Ramos MS , Razuck FB 
Published: May 2021

Abstract
In routine operations of services and standard practices that use ionizing radiation sources, safety is required in relation to the calculations of the variables, according to the operation. The safe distance to operate at, the conversions of units and other important quantities need metrological precision, to avoid any unfortunate unwanted affects. In this sense, this work aims to demonstrate the benefits of an App that can be used free of charge for calculating dosimetric quantities. This App proved to be efficient and accurate in tests, for example, in calculations for Gammagraphy.