bluuebunny/crossref_metadata_2025_split huggingface dataset:
A combined TEM and SAXS study of the growth and self-assembly of ultrathin Pt nanowires
Authors: McGuire Scott C , Zhang Yugang , Wong Stanislaus S 
Published: August 2022

Abstract
Ultrathin Pt nanowires possess high activity for various electrocatalytic applications. However, little work has focused on understanding their growth mechanisms. Herein, we utilize a combination of time-dependent, ex situ transmission electron microscopy (TEM) and small angle x-ray scattering (SAXS) techniques to observe the growth process in addition to associated surfactant-based interactions. TEM images indicate that initially nanoparticles are formed within 30 s; these small ‘seed’ particles quickly elongate to form ultrathin nanowires after 2 min. These motifs remain relatively unchanged in size and shape up to 480 min of reaction. Complementary SAXS data suggests that the initial nanoparticles, which are coated by a surfactant bilayer, arrange into a bcc superlattice. With increasing reaction time, the bcc lattice disappears as the nanoparticles grow into nanowires, which then self-assemble into a columnar hexagonal structure in which the individual nanowires are covered by a CTAB monolayer. The hexagonal structure eventually degrades, thereby leading to the formation of lamellar stacking phases comprised of surfactant bilayers. To the best of our knowledge, this is the first time that SAXS has been used to monitor the growth and self-assembly of Pt nanowires. These insights can be used to better understand and rationally control the formation of anisotropic motifs of other metallic nanostructures.
Intratidal compliance of the lung and the total respiratory system
Authors: Dzierzawski Patryk , Oswalt Jakob , Wirth Steffen , Schumann Stefan 
Published: August 2022

Abstract

Objective. The worldwide rising quantity of surgeries and the corresponding need of mechanical ventilation means a rising number of patients are at risk of suffering from post-operative pulmonary complications. To prevent this risk, individual mechanics of the lung should be considered when setting the parameters of mechanical ventilation. Intratidal compliance analysis based on transpulmonal pressure would provide an estimate for individual lung mechanics. The downside of such measure, however, is its invasiveness. Accurate measurement requires recording of the esophageal pressure as surrogate for the actual pleural pressure. Measuring pressure at the airway opening is considerably easier, but the resulting mechanics of the respiratory system may not represent the actual lung mechanics in a straightforward fashion. Approach. In order to evaluate if the mechanics of the lungs are represented by analysis of the mechanics of the respiratory system we determined intratidal dynamic compliance-volume profiles of both in 23 lung-healthy mechanically ventilated patients undergoing elective surgery. We also compared the accuracy of the compliance profiles resulting from analysis of the total breath with those resulting from the analysis of inspiration data only. Main results. When the whole breath was analyzed 54.3%, and with only inspiration data 69.6%, of compliance profiles of the respiratory system matched those of the lung. With both approaches profiles of the lung and the respiratory system matched or deviated by only one neighboring step (75% whole breath, 91.3% inspiration only), and never contradicted each other. Significance. Compliance profiles calculated from volume and pressure data of the respiratory system are an adequate surrogate for the compliance profiles of the lungs of lung-healthy patients. Therefore, invasive assessment of esophageal pressure for achievement of intrapleural pressure is unnecessary. The compliance profiles based on only inspiratory data appear more sensitive for indicating intratidal derecruitment than those based on data of the whole breath.
Kinetic investigation of plasma catalytic synthesis of ammonia: insights into the role of excited states and plasma-enhanced surface chemistry
Authors: Sun Jintao , Chen Qi , Zhao Xuteng , Lin He , Qin Wanyue 
Published: August 2022

Abstract
The present work investigates the kinetics of catalytic ammonia synthesis in a N2/H2 mixture activated by a nanosecond pulsed discharge plasma experimentally and numerically. X-ray diffraction, high-resolution transmission electron microscopy and x-ray photoelectron spectroscopy are combined to characterize the morphology and surface electronic properties of the catalyst. Special attention is placed on the role of excited species in promoting the formation of important intermediates and the plasma-enhanced surface chemistry. A detailed kinetic mechanism consisting of atoms, radicals, excited species, molecules, ions, and surface species is developed and studied by incorporating a set of the electron impact reactions, reactions involving excited species, ionic reactions, direct and dissociative adsorption reactions, and surface reactions. A zero-dimensional model incorporating the plasma kinetics solver is used to calculate the temporal evolution of species densities in a N2/H2 plasma catalysis system. The results show that the coupling of Fe/γ–Al2O3 catalyst with plasma is much more effective in ammonia synthesis than the Fe/γ–Al2O3 catalyst alone and plasma alone. The numerical model has a good agreement with experiments in ammonia formation. The path flux analysis shows the significant roles of excited species N(2D), H2(v1), N2(v) in stimulating the formation of precursors NH, NH2, and adsorbed N(s) through the pathways N(2D) + H2 → NH + H, H2(v1) + NH → NH2 + H and N2(v) + 2Fe(s) → N(s) + N(s), respectively. Furthermore, the results show that the adsorption reaction N + Fe(s) → N(s) and Eley–Ridel interactions N(s) + H → NH(s), N + H(s) → NH(s), NH + H(s) → NH2(s) and NH2 + H(s) → NH3(s) can kinetically enhance the formation of ammonia, which further highlights the plasma-enhanced surface chemistry. This work provides new insights into the roles of excited species and plasma-enhanced surface chemistry in the plasma catalytic ammonia synthesis.
Surface processes involving nitrogen molecules and atoms on silica surface at low temperature: the role of energy exchanges
Authors: Rutigliano Maria , Pirani Fernando 
Published: August 2022

Abstract
The dynamics of elementary surface processes, promoted by nitrogen atoms and molecules impacting a silica surface, has been investigated by adopting a semiclassical scattering method. The appropriate treatment of the long-range interaction forces emphasized the crucial control exercised by the weakly bound precursor state on the stereo-dynamics of all basic elementary processes occurring at the gas-surface inter-phase. Molecular dynamics simulations have highlighted the role of vibrationally excited molecules in plasma dynamics. Indeed, N2 molecules, impinging the surface in low-medium vibrational levels, conserve the initial vibration state while are inelastically scattered, rotationally excited and translationally colder. Moreover, N2 molecules nascent from the atomic recombination on the surface have a fair probability of forming at very high vibrational levels, with a consistent part of reaction exothermicity transferred to the translational energy. Consequently, the surface induces a strong non-equilibrium condition, influencing directly the dynamics of processes occurring in the plasma bulk.
A computational study of accelerating, steady and fading negative streamers in ambient air
Authors: Guo Baohong , Li Xiaoran , Ebert Ute , Teunissen Jannis 
Published: August 2022

Abstract
We study negative streamers in ambient air using a 2D axisymmetric fluid model. Depending on the background electric field, we observe accelerating, steady and fading negative streamers. Fading occurs in low background fields, when negative streamers lose their field enhancement and when their velocities become comparable to their maximal electron drift velocities. Our focus is on the steady propagation mode, during which streamer properties like radius and velocity hardly change. However, this mode is unstable, in the sense that a small change in conditions leads to acceleration or deceleration. We observe steady negative streamers in background fields ranging from 9.19 kV cm−1 to 15.75 kV cm−1, indicating that there is no unique steady propagation field (or stability field). Another finding is that steady negative streamers are able to keep propagating over tens of centimeters, with only a finite conductive length behind their heads, similar to steady positive streamers. Approximately linear relationships are observed between the optical diameter and properties like the streamer velocity and the streamer head potential. From these linear relations, we obtain rough lower bounds of about 0.27 mm to 0.35 mm for the minimal optical diameter of steady negative streamers. The lowest background field in which a steady negative streamer could be obtained is 9.19 kV cm−1. In contrast, steady positive streamers have recently been obtained in a background field as low as 4.05 kV cm−1. We find that the properties of steady negative and positive streamers differ significantly. For example, for steady negative streamers the ratio between streamer velocity and maximal electron drift velocity ranges from about 2 to 4.5, whereas for steady positive streamers this ratio ranges from about 0.05 to 0.26.
Multiband effects in thermoelectric and electrical transport properties of kagome superconductors AV3Sb5 (A = K, Rb, Cs)
Authors: Mi Xinrun , Xia Wei , Zhang Long , Gan Yuhan , Yang Kunya , Wang Aifeng , Chai Yisheng , Guo Yanfeng , Zhou Xiaoyuan , He Mingquan 
Published: August 2022

Abstract
We studied the effects of multiband electronic structure on the thermoelectric and electrical transport properties in the normal state of kagome superconductors AV3Sb5 (A = K, Rb, Cs). In all three members, the multiband nature is manifested by sign changes in the temperature dependence of the Seebeck and Hall resistivity, together with sublinear response of the isothermal Nernst and Hall effects to external magnetic fields in the charge ordered state. Moreover, ambipolar transport effects appear ubiquitously in all three systems, giving rise to sizable Nernst signal. Finally, possible origins of the sign reversal in the temperature dependence of the Hall effect are discussed.
Unconditionally secure digital signatures implemented in an eight-user quantum network*
Authors: Pelet Yoann , Puthoor Ittoop Vergheese , Venkatachalam Natarajan , Wengerowsky Sören , Lončarić Martin , Neumann Sebastian Philipp , Liu Bo , Samec Željko , Stipčević Mario , Ursin Rupert , Andersson Erika , Rarity John G , Aktas Djeylan , Joshi Siddarth Koduru 
Published: August 2022

Abstract
The ability to know and verifiably demonstrate the origins of messages can often be as important as encrypting the message itself. Here we present an experimental demonstration of an unconditionally secure digital signature (USS) protocol implemented for the first time, to the best of our knowledge, on a fully connected quantum network without trusted nodes. We choose a USS protocol which is secure against forging, repudiation and messages are transferrable. We show the feasibility of unconditionally secure signatures using only bi-partite entangled states distributed throughout the network and experimentally evaluate the performance of the protocol in real world scenarios with varying message lengths.
Momentum transfer models of interacting dark energy
Authors: Linton Mark S. , Crittenden Robert , Pourtsidou Alkistis 
Published: August 2022

Abstract
We consider two models of interacting dark energy, both of which interact only through momentum exchange. One is a phenomenological one-parameter extension to wCDM, and the other is a coupled quintessence model described by a Lagrangian formalism. Using a variety of high and low redshift data sets, we perform a global fitting of cosmological parameters and compare to ΛCDM, uncoupled quintessence, and wCDM. We find that the models are competitive with ΛCDM, even obtaining a better fit when certain data sets are included.
Capture of primordial black holes in extrasolar systems
Authors: Lehmann Benjamin V. , Webber Ava , Ross Olivia G. , Profumo Stefano 
Published: August 2022

Abstract
The vast datasets associated with extrasolar systems promise to offer sensitive probes of new physics in the near future. We consider the possibility that such systems may capture primordial black holes (PBHs) or other exotic compact objects, giving rise to unique observational signatures. We estimate the rate of captures by extrasolar systems, accounting for several distinct mechanisms. We find that the capture rate is negligible unless PBHs account for the entirety of dark matter in a narrow mass range just above the threshold of existing constraints from evaporation. In this scenario, luminous evaporating PBHs may be detectable by exoplanet searches.
The processing network of high-frequency acoustoelectric signal in the living rat brain
Authors: Song Xizi , Huang Peishan , Chen Xinrui , Xu Minpeng , Ming Dong 
Published: August 2022

Abstract

Objective. Acoustoelectric brain imaging (ABI) is a potential noninvasive electrophysiological neuroimaging method with high spatiotemporal resolution. At the focal spot of the focused ultrasound, with the couple of acoustic and electric fields, high-frequency acoustoelectric (HF AE) signal is generated. Because the brain is a volume conductor, HF AE signal can be detected in other brain cortex. The processing of HF AE signal is critical for improving decoding precision, further improving the spatial resolution performance of ABI. This study investigates the processing network of HF AE signal in the living rat brain. Approach. When HF AE generated on the left primary visual cortex (V1-L), low-frequency (LF) electroencephalography and HF AE signals on different cortex were recorded at the same time. Firstly, AE signal on different sides of the brain cortex were compared, including prefrontal cortex (FrA) and primary somatosensory cortex (S1FL). Then, we constructed and analyzed functional networks of two signals. Main results. In the same cortex, HF AE signal on the right side had stronger intensity. And compared with LF networks, HF AE network had larger global efficiency and shorter characteristic path length, denoting the stronger processing and transmission of AE signal. Additionally, in HF AE network, the node had significantly increased local properties and the connection were concentrated in the occipital lobe, reflecting the occipital lobe plays an important role in the processing. Significance. Experiment results demonstrate that, compared with LF network, HF AE network is more efficient and had stronger transmission capabilities. And the connection of HF AE network is concentrated in the occipital lobe. This work preliminarily reveals the HF AE signal processing, which is significant for improving the ABI quality and provides a new insight for understanding the brain HF signal.
AI Acceleration Enabled by Nanoelectronic Memristive Devices
Authors: Bordanov I A , Zuev A D , Danilin S N , Khranilov V P , Bukvarev E A , Kim S , Gryaznov E G , Mikhaylov A N , Shchanikov S A 
Published: August 2022

Abstract
Here we present an analysis of the current state in the field of development of hardware accelerators of artificial intelligence (AI). Despite the fairly good progress made over the past decades, this area is experiencing a number of significant difficulties in its development. The solution to this problem lies in the application of new approaches to the organization of computing, in particular, computing in memory enabled by nanoelectronic memristive devices. We provide an overview of state-of-art systems, as well as our own version of the experimental concept of AI accelerators based on metal-oxide memristive devices and the massively parallel architecture for information processing.
Investigation of material heating under the action of ultrashort laser pulses
Authors: Kharkova A V , Khorkov K S , Egorova A V 
Published: August 2022

Abstract
The aim of this work was to study the heating of an AISI 304 plate in the ablative mode of femtosecond laser pulses. The variable parameter was the change in the speed of movement of the laser beam over the treated surface. The paper presents the results of measuring the heating temperature of the sample surface exposed to laser radiation without scanning laser radiation with different pulse energies. The results of the dependence of the heating of the material surface on the speed of movement of the laser radiation with a constant number of acting pulses are presenting.
Research of the physical and mechanical properties of AISI 321 steel manufactured by selective laser melting
Authors: Zhdanov A V , Raznoschikov A S , Voznesenskaya A A , Poltorakova K S , Belyaev I V 
Published: August 2022

Abstract
In this paper, the problems of creating parts by selective laser melting from AISI 321 powder material are considered. Samples were made from powder material with a granulometric composition of 10-63 microns at a selective laser melting plant. Microslips were made to study the physical and mechanical properties. The structure of the samples and their porosity were evaluated using optical microscopy. The change of physical and mechanical properties depending on the change in the scanning speed is investigated. The connection between the modes of selective laser melting and the physical and mechanical properties of the resulting products has been established.
Birefringent tuner for narrowband alexandrite laser
Authors: Putilov A G , Antipov A A , Shepelev A E , Osipov A V , Arakelian S M 
Published: August 2022

Abstract
This article discusses the possibility of using Lyot interference-polarization tuners to create tunable lasers. The use of various variations and layouts of phase-shifting plates makes it possible to generate both dual-wave and single-wave radiation with the possibility of tuning. The tuning range depends both on the specific type of tuner used and on the parameters of the cavity and active medium. Dual-wave and single-wavelength generation of an alexandrite laser is demonstrated.
Deflection of particles of a laser erosion plume under the action of a high-voltage electrostatic field during ablation processing of titanium
Authors: Firsov I V , Zolotov A N , Efremov I M , Egorova A V 
Published: August 2022

Abstract
The ablative particles of the laser erosion torch during the processing of titanium with subpicosecond pulses were analyzed for vertical deflection under the action of an electrostatic field. The installation of a solid-state ytterbium laser with a radiation wavelength of 1030 nm was used. The photographs of the registered deviations of ablation particles in the region of propagation of the electrostatic field were obtained. The dependence of the vertical deflections of ablated particles on the laser pulse energy and the distance from the electrodes to the target is calculated.
Fractal models of the PbTe nanocluster structures on a solid surface
Authors: Bukharov D N , Abramov A S , Novikova O A , Samyshkin V D 
Published: August 2022

Abstract
A fractal approach is proposed for modeling systems of PbTe nanoclusters on a solid surface. The systems under consideration were generated by solid-phase laser modification. For the obtained samples, their fractal dimension was estimated. In accordance with the proximity to it, the corresponding chaotic fractal structures were selected.
Topological photonics – 4D-laser technology for nanoelectronics on new physical principles to create the element base of next generation
Authors: Kucherik A , Kutrovskaya S , Bukharov D , Khudaiberganov T 
Published: August 2022

Abstract
In the paper we consider femtonanophotonics of the topological controlled low-dimensional dynamic structures in thin films induced by laser radiation on the surface of solids, using the achievements of quantum technologies and nonlinear dynamics for different regimes of electroconductivity.
We completed several laser procedures for obtaining nanostructures and thin films with controllable topology. They occur under the development of different nonlinear processes in the system (thermodiffusion, gas-dynamic evaporation in pore-like structures with bubbles, ablation products, ballistic movement of the particles in liquid). A simple 2-steps mechanism for enhancement of quantum behavior (e.g. in electroconductivity) exists for different conditions.
First, when inelastic length l
inelastic > a
cluster (size of cluster) we have no incoherent electron-phonon (e-ph) scattering, and coherent process occurs with scale ℓcoh.
Second, when de Broglie length λdB ≡ ℓcoh > Λ (Λ – spatial period of the nanoparticle distribution) the coherent tunneling without loss occurs, and a long-range order with interference of the states takes place in the medium due to lattice structure in system.
Under such conditions, the electroconductivity enhancement can result in paradoxical phenomenon when electroconductivity in granulated structure may be higher than in monolith sample due to many surface/boundary units – like topological states in topological insulator.
Distribution of laser radiation in opaque porous media
Authors: Voznesenskaya A A , Raznoschikov A S , Galkin A F , Oparin E S , Zavitkov A V , Loktev A S , Gusev D S 
Published: August 2022

Abstract
The work is aimed at studying the interaction of laser radiation and powder material, in particular, the nature of propagation and absorption of laser radiation in a porous medium. Measurements of the nature of propagation and interaction of laser radiation with a powder material were carried out using a low-power laser in the “before reflow” mode. The paper presents the results of measuring the intensity of the passage of a laser beam through layers of powder material made of an aluminum alloy AlSi10Mg with an average fraction of 30 μm of various thicknesses. The results of measuring the heating of the powder material under the action of laser radiation and the dependence of the depth of penetration of the laser beam into the powder material are presented.
Design of multi-layer grid in a giant electrostatic collection vessel of ultra-high sensitivity radon monitor
Authors: Mo Yixiang , Tang Jianfeng , Fan Zhongkai , Hu Tao , Lin Fen , Xie Ruomei , Yuan Shuai , Liu Shuaibin , Yuan Hongzhi , Tan Yanliang 
Published: August 2022

Abstract
Developing an ultra-high sensitivity electrostatic
collection radon monitor benefits the scientific experiments of
China Jinping Underground Laboratory. Here, a one cubic meter
electrostatic collection vessel with a multi-layer hemispherical
metal grid was designed to increase the collection efficiency of
positively charged Po-218 ions. The 3D model of the giant
electrostatic collection vessel was constructed using the COMSOL
Multiphysics simulation software, and the potential and electric
field distributions in the vessel were simulated. Numerical
simulation results were obtained according to the different radii
and voltages applied to the grid. The electric field between the
vessel wall and grid, between two grids, and between the grid and
surface of the PIPS detector must be set uniformly to reduce the
collection time of the positively charged Po-218 ions. Simulation
results showed that setting a charged metal grid in the vessel can
optimize the electric field distribution, and setting a two-layer
charged metal grid in the giant vessel can further increase the cost
performance. The average collection times of the electrostatic
collection vessel with the two-layer grid along the vertical and
oblique lines approximately 15% and 13% of that without the
grid. The rates of positively charged Po-218 ions that could pass
through the one and two-layer metal grids were 86.78% and
50%. Optimizing the electric field can greatly increase the
sensitivity of radon monitors and reduce the humidity restrictions.