bluuebunny/crossref_metadata_2025_split huggingface dataset:
Establishment of heterochromatin in domain-size-dependent bursts
Authors: Nickels Jan Fabio , Edwards Ashleigh Katrine , Charlton Sebastian Jespersen , Mortensen Amanda Møller , Hougaard Sif Christine Lykke , Trusina Ala , Sneppen Kim , Thon Geneviève 
Published: April 2021

Significance
How repressive heterochromatic states propagate along chromosomes and are subsequently maintained for many cell divisions remain important unanswered questions in biology. Combining mathematical modeling and single-cell measurements, we find that heterochromatin does not propagate in a purely linear manner as often assumed. Rather, sudden transitions can affect large domains globally at once. We suggest this is due to long-range interactions that bring distant nucleosomes close to each other to facilitate their modification. This supports the notion that the compartmentalization of chromatin components within the nucleus and the folding of chromatin into loops dynamically control heterochromatin propagation in three dimensions by bringing nucleosomes and their modifiers into close proximity.
The electrohydrodynamic force distribution in surface AC dielectric barrier discharge actuators: do streamers dictate the ionic wind profiles?
Authors: Kourtzanidis K , Dufour G , Rogier F 
Published: April 2021

Abstract
We show that the spatio-temporal electrohydrodynamic (EHD) force production in surface alternative current-dielectric barrier discharge (AC-DBD) actuators is strongly influenced by both the streamer regime during the positive phase and the micro-discharge regime during the negative phase. Focusing on the spatial EHD force profiles, we demonstrate that the ionic wind spatial distribution can only be explained by the positive contribution of the streamer regime. The location of maximum ionic wind is found to be directly linked with the maximum elongation of the streamers at several millimeters from the exposed electrode. In both positive and negative phases of the AC-DBD operation, residual volumetric and surface charges once again linked to the streamer formation and afterburn, result to a variety of positive EHD force zones which, when time-averaged in one AC period, contribute to the generation of the experimentally observed induced thin wall jet. Through a thorough elaboration of our numerical results, we provide an illustrative explanation of the EHD force spatio-temporal evolution, showcase the importance of streamers and retrieve a correct representation of the ionic wind spatial profiles when compared to experiments.
Impact of oxygen flow rate on performance of indium-tin-oxide-based RRAMs
Authors: Tsai Tsung-Ming , Tan Yung-Fang , Wu Cheng-Hsien , Yang Chih-Cheng , Chen Wen-Chung , Lin Chun-Chu , Wu Pei-Yu , Zhang Yong-Ci , Chou Sheng-Yao , Chen Zi-Yu , Lin Tzu-Heng 
Published: April 2021

Abstract
This paper investigates the effect of oxygen flow rates on the performance of the resistive random access memory (RRAM) of indium-tin-oxide (ITO)/ITO(O2)/TiN configuration. By using a co-sputtering deposition system with oxygen gas at different flow rates, oxygen-rich ITO thin films, such as the RRAM switching layer, can be realized. The relationship between oxygen flow rates and electrical characteristics is provided in this research. Further, the material analyses indicate that the oxygen exhibits different bonding characteristics. As a result, the device with the lower oxygen flow rate has better electrical characteristics and reliability. In addition, to explain the experimental results, the Schottky emission conduction mechanism for the high-resistance state and the Ohmic conduction mechanism for the low-resistance state are determined through the current fitting results, and appropriate models are proposed.
Exploration of structural, thermal stability and band-gap tunability of organic and inorganic mixed cation (MA)1−x
Cs
x
PbBr3 perovskite harvester via ultrasonication synthesis route
Authors: Singh Rajan Kumar , Masood Khalid Bin , Jain Neha , Tamrakar Radha , Singh Jai , Kumar Ranveer 
Published: April 2021

Abstract
Extensive investigation over the last few years has been done on halide based perovskite light harvester due to higher power conversion efficiency but the thermal stability with organic cation i.e. methylamine is challenging for the commercialization. Therefore, for improved structural and thermal stability, it is significant to develop a mixed cation base perovskite compound. To improve the thermal and structural stability of the material and easy synthesis method for industrialization of the material, we have demonstrated the compositional engineering of MA/CsPbBr3 perovskite material via ultrasonication synthesis process. The x-ray diffraction, transmission electron microscope, diffuse reflectance spectrometer and simultaneous thermal analyzer (STA) analysis were performed in order to understand the impact of the Cs+ into MAPbBr3 perovskite structure. Structural study reveals that up to 40% Cs+ incorporation into MAPbBr3 has pure Pm−3m cubic phase of perovskite compound with continuously increase in micro strain and lattice contraction. On the other hand, with increasing the concentration of Cs+ than MA+, optical band gap slightly increases. The thermodynamic behavior and thermal stability of the sample was studied with STA (differential scanning calorimetry/thermogravimetry). For the new generation optoelectronics with admirable stability, we believe that pure phase MA0.60Cs0.40PbBr3 perovskite compound may be a promising candidate.
Exploring phase transitions and the emergence of structural complexity at the ESRF extremely brilliant source
Authors: Mezouar M , Garbarino G 
Published: April 2021

Abstract
The underlying mechanisms of phase transitions and the emergence of complexity are long-standing fundamental subjects for which a complete and unified description is still missing. This is due to the intrinsic nature of condensed matter, which contains a very large number of interacting particles. The partial or complete resolution of these open questions will require a considerable development of the experimental and theoretical means. In this context, the newly developed extremely brilliant x-ray source at the European Synchrotron Radiation Facility with its unprecedented performances will provide the scientific community with a unique tool to tackle such challenging objectives. In this review article, we will discuss, through some selected examples, the potential impact this new instrument could have in the short and long term in this field of research.
An adaptive algorithm for multipath-assisted simultaneous localization and mapping using belief propagation
Authors: Dan Zesheng , Lian Baowang , Tang Chengkai 
Published: April 2021

Abstract
In multipath-assisted simultaneous localization and mapping (SLAM), position-related information (delays and angles) in multipath components of radio signals is used to simultaneously localize user equipment (UE) and map the environment. Multipath-assisted SLAM often involves unknown parameters that are potentially time varying, such as measurement noise. Knowledge of the measurement noise is of critical importance to multipath-assisted SLAM, and uncertainty in such knowledge will seriously affect estimation accuracy. We address this challenge by improving the belief propagation (BP)-based SLAM algorithm and proposing an adaptive multipath-assisted SLAM algorithm in a Bayesian tracking framework, which enables accommodation of a model mismatch of the measurement noise online. Specifically, we describe the evolution of the measurement noise standard deviation via a Markov chain and integrate it into the factor graph representing the Bayesian model of the multipath-assisted SLAM. Then, the BP message passing algorithm is leveraged to calculate the marginal posterior distributions of the UE, environmental features and the measurement noise standard deviation to achieve SLAM and the adaptive adjustment of the measurement noise. Finally, the experimental results verify the robustness of the proposed adaptive multipath-assisted SLAM algorithm against the uncertainty of the measurement noise.
Survivability of the thermographic phosphors YAG:Pr and SMP:Sn in a premixed flame
Authors: Kopf A , Bardi M , Kohler E , Endres T , Bruneaux G , Schulz C 
Published: April 2021

Abstract
The survivability of two thermographic phosphors, YAG:Pr3+ and SMP:Sn2+ ((Sr,Mg)3(PO4)2:Sn2+), in a combustion environment is studied in the post-flame regime of a premixed propane/air flame. While the laser-induced luminescence of YAG:Pr3+ can be exploited for in situ temperature measurements in the exhaust gas above the flame, there is no in situ detectable luminescence for SMP:Sn2+ for any reaction conditions within the stability limits of the flame. The phosphor particles are recaptured above the flame and ex situ analyzed for chemical or structural changes using microscopic analysis (SEM/EDX) and x-ray diffraction. The microscopic analysis of post-flame YAG:Pr3+ does not show any alteration, whereas morphology and chemical composition of SMP:Sn2+ have been modified upon passing through the reaction zone, which is responsible for the loss of its luminescence properties.
Influencing factors and growth kinetics analysis of carbon nanotube growth on the surface of continuous fibers
Authors: Qin Jianjie , Wang Chengguo , Yao Zhiqiang , Ma Ziming , Cui Xuanhao , Gao Quan , Wang Yanxiang , Wang Qifen , Wei Huazhen 
Published: April 2021

Abstract
Carbon nanotubes (CNTs) were continuously grown on the surface of the moving carbon fiber by chemical vapor deposition method using a custom-designed production line to prepare composite reinforcements on a large-scale. The systematic study of different parameters affecting the CNT growth revealed simple growth kinetics, which helps to control the surface morphology and structural quality of CNTs. Since hydrogen maintains the activity of the catalyst, it promotes the growth of CNTs in a continuous process. The increase of acetylene partial pressure promotes the accumulation of amorphous or graphite carbon on the catalyst surface, resulting in the decrease of CNT growth rate when acetylene concentration reaches 40%. The growth temperature significantly affects the CNT diameter and structural quality. As the temperature increases, the crystallinity of the tube wall increases obviously, and the CNT diameter increases due to the aggregate growth of the catalyst particles. According to the Arrhenius formula, the apparent activation energy is observed to be 0.67 eV, which proves that both bulk diffusion and surface diffusion exist when activated carbon passes through the catalyst to form CNTs.
Widely tunable surface plasmon resonance and uniquely superior SERS performance of Au nanotube network films
Authors: Lin Yongxing , Wang Liang , Zhang Haibao , Wu Linfeng , Fan Huibo , Liu Xianglan , Zheng Ruobing , Tian Xingyou , He Hui 
Published: April 2021

Abstract
Three-dimensional Au network films with flexibility and transferability were fabricated based on sputtering deposition onto electrospun nanofibers as a template. The films are constructed using long Au nanotubes that are cross-linked with each other and that have dense nanoparticles on the tube wall surface. The surface plasmon resonance (SPR) peaks for the films are tunable in a wide range, from visible light to the near-infrared region, by tuning the inner diameter and/or wall thickness of the nanotubes. Such structured film exhibits significant surface-enhanced Raman scattering (SERS) activity with good signal uniformity and stability, and possesses great potential in the in situ detection of trace organic pollutants on a solid surface by simple transferring. This study provides a Au film with a unique structure and widely tunable SPR for in situ SERS sensing and other needs.
Kinetics control over the Schiff base formation reaction for fabrication of hierarchical porous carbon materials with tunable morphology for high-performance supercapacitors
Authors: Liu Ling , Li Yuntong , Lu Zhenwu , Chen Ting , Cai Qipeng , Xu Yiting , Zeng Birong , Yuan Conghui , Kuo Shiao-Wei , Dai Lizong 
Published: April 2021

Abstract
Schiff base formation reaction is highly dynamic, and the microstructure of Schiff base polymers is greatly affected by reaction kinetics. Herein, a series of Schiff base cross-linked polymers (SPs) with different morphologies are synthesized through adjusting the species and amount of catalysts. Nitrogen/oxygen co-doped hierarchical porous carbon nanoparticles (HPCNs), with tunable morphology, specific surface area (SSA) and porosity, are obtained after one-step carbonization. The optimal sample (HPCN-3) possesses a coral reef-like microstructure, high SSA up to 1003 m2 g−1, and a hierarchical porous structure, exhibiting a remarkable specific capacitance of 359.5 F g−1 (at 0.5 A g−1), outstanding rate capability and cycle stability in a 1 M H2SO4 electrolyte. Additionally, the normalized electric double layer capacitance (EDLC) and faradaic capacitance of HPCN-3 are 0.239 F m−2 and 10.24 F g−1 respectively, certifying its superior electrochemical performance deriving from coral reef-like structure, high external surface area and efficient utilization of heteroatoms. The semi-solid-state symmetrical supercapacitor based on HPCN-3 delivers a capacitance of 55 F g−1 at 0.5 A g−1, good cycle stability of 86.7% after 5000 GCD cycles at 10 A g−1, and the energy density ranges from 7.64 to 4.86 Wh kg−1.
Branching TiO2 nanowire arrays for enhanced ethanol sensing
Authors: Jin Qi , Wen Wei , Zheng Shilie , Jiang Rui , Wu Jin-Ming 
Published: April 2021

Abstract
Nanostructure modulation is effective to achieve high performance TiO2-based gas sensors. We herein report a wet-chemistry route to precipitate directly branched TiO2 nanowire arrays on alumina tubes for gas sensing applications. The optimized branched TiO2 nanowire array exhibits a response of 9.2 towards 100 ppm ethanol; whilst those of the pristine TiO2 nanowire array and the branched TiO2 nanowire powders randomly distributed are 5.1 and 3.1, respectively. The enhanced response is mainly contributed to the unique porous architecture and quasi-aligned nanostructure, which provide more active sites and also favor gas migration. Phase junctions between the backbone and the branch of the branched TiO2 nanowire arrays help the resistance modulation as a result of potential barriers. The facile precipitation of quasi-aligned arrays of branched TiO2 nanowires, which are in situ grown on ceramic tubes, thus provides a new economical synthetic route to TiO2-based sensors with excellent properties.
Prediction of high-performance scenario with localized magnetic shear reversal on EAST tokamak
Authors: Zhang X X , Wu M Q , Li G Q , Ding S Y , Liu X J , Qian J P , Gong X Z , Gao X , Gao S L , Wu X H , Li K 
Published: April 2021

Abstract
An advanced scenario with high poloidal beta, large-radius internal transport barriers (ITBs) and localized reversed-shear q-profile, has been demonstrated in DIII-D/EAST joint experiments recently on the DIII-D tokamak. This scenario is also one of the future explorations on EAST. In this article, integrated modeling has been utilized to explore the regime with localized reversed-shear q-profile and high performance based on the developed long-pulse scenario on EAST. A scenario with a strong reversed-shear q-profile has been achieved with the combination of 2 MW off-axis ECH, 2.6 MW LHW and 2 MW NBI (H98y2 ∼ 1.35,

β

P

∼ 2.56,

β

N

∼ 2.23,

f

bs

∼
56
%

). In addition, a small amount (∼0.1 MW) of centrally deposited ECH facilitates the generation of the bootstrap current on or near the axis, and hence reduces the level of the q-profile in this region; thus, a scenario with localized magnetic shear reversal and strong large-radius ITBs is obtained (H98y2 ∼ 1.4,

β

P

∼ 2.66,

β

N

∼ 2.31,

f

bs

∼
60
%

). Modeling predictions indicate that off-axis ECH/LHW and high plasma density promote the formation of large-radius ITBs. A further increase in the injected power of centrally deposited ECH (0.15 MW) or NBI (4 MW) leads to an increase in the temperature gradient, especially the electron temperature near the axis, and large-radius ITBs disappear in all channels (T
e, T
i, n
e); also, the confinement quality decreases. The bootstrap current density profiles and LHW-driven current profiles tend to peak near the axis due to the increase in electron temperature profiles, which eventually leads to peaked total current profiles, similar to the EAST long-pulse scenario. Changes in magnetic shear result in the disappearance of large-radius ITBs. Modeling validation will be carried out in the near future on the EAST tokamak.
Theoretical description of chirping waves using phase-space waterbags
Authors: Hezaveh H , Qu Z S , Hole M J , Dewar R L 
Published: April 2021

Abstract
The guiding centre dynamics of fast particles can alter the behaviour of energetic particle (EP) driven modes with chirping frequencies. In this paper, the applicability of an earlier trapped/passing locus model (Hezaveh et al 2017 Nucl. Fusion
57 126010) has been extended to regimes where the wave trapping region can expand and trap ambient particles. This extension allows the study of waves with up-ward and down-ward frequency chirping across the full range of EP orbits. Under the adiabatic approximation, the phase-space of EPs is analysed by a Lagrangian contour approach where the islands are discretised using phase-space waterbags. In order to resolve the dynamics during the fast formation of phase-space islands and find an appropriate initialisation for the system, full-scale modelling is implemented using the bump-on-tail code. In addition to investigating the evolution of chirping waves with deepening potentials in a single resonance, we choose specific pitch-angle ranges in which higher resonances can have a relatively considerable contribution to the wave-particle interaction. Hence, the model is also solved in a double-resonance scenario where we report on the significant modifications to the behaviour of the chirping waves due to the 2nd resonance. The model presented in this paper gives a comprehensive 1D paradigm of long range frequency chirping signals observed in experiments with both up-ward and down-ward chirping and multiple resonances.
Optical constants of crystalline Bi2Sr2CaCu2O

8+δ

by Brillouin light scattering spectroscopy
Authors: McNiven B D E , LeBlanc J P F , Andrews G T 
Published: April 2021

Abstract
Room-temperature optical constants of crystalline Bi2Sr2CaCu2O

8
+
δ

were determined using data extracted from Brillouin light scattering spectra. Optical extinction coefficient-to-refractive index ratios at a wavelength of 532 nm were obtained from bulk phonon peak linewidth and frequency shift measurements and range from

0.19
⩽
2
κ
/
n
⩽
0.29

for directions close to the crystallographic c-axis. These ratios, and optical extinction coefficients, absorption coefficients, and imaginary parts of the dielectric function determined from these ratios and known refractive index, are in general agreement with values found in optical reflectance studies, but are 5–7 times larger than those extracted from optical interference measurements.
Saturating multiple ionization in intense mid-infrared laser fields
Authors: Haniel Franz E , Schröder Hartmut , Kahaly Subhendu , Nayak Arjun , Dumergue Mathieu , Mondal Sudipta , Zoltán Filus , Flender Roland , Kurucz Máté , Haizer Ludovit , Kiss Bálint , Charalambidis Dimitris , Kling Matthias F , Tzallas Paraskevas , Bergues Boris 
Published: April 2021

Abstract
The interpretation of experimental data from novel mid-infrared few-cycle laser sources requires an understanding of ionization mechanisms and knowledge about related ion yields. Experimental studies have indicated sequential double ionization as the dominant process above 1014 W cm−2. These results contradict a recent prediction that in this spectral region, non-sequential processes dominate the double ionization of xenon up to intensities of about 1015 W cm−2. In either case, the ratio of doubly to singly charged xenon yield reported in previous studies has been limited to a few percent, indicating a regime well below the onset of saturation of the double ionization process. We present an experimental study of double ionization of xenon and krypton atoms exposed to intense near four-cycle pulses at 3.2 μm. Our experiments rely on the ion microscopy technique, which facilitates the detection of ions originating from a restricted region within the interaction volume, thereby reducing the impact of focal averaging. Our measurements suggest that at intensities of close to 1.2 × 1014 W cm−2, double ionization of xenon and krypton is already significantly saturated. In particular, we find a doubly to singly charged yield ratio of about 75 percent for xenon and 25 percent for krypton. We compare our results with the predictions of different models accounting for the effects of volume averaging and focal geometry. We find that in the deeply saturated regime of our experiment, the Perelomov–Popov–Terentyev theory significantly underestimates the observed double ionization yield.
Radial profile of bottom quarks in jets in high-energy nuclear collisions *
Authors: Wang Sa , Dai Wei , Zhang Ben-Wei , Wang Enke 
Published: April 2021

Abstract
Angular correlations between a heavy quark (HQ) and its tagged jet are potentially new tools to gain insight into the in-medium partonic interactions in relativistic heavy-ion collisions. In this work, we present the first theoretical study on the radial profiles of B mesons in jets in Pb+Pb collisions at the Large Hadron Collider (LHC). The initial production of a bottom quark tagged jet in p+p is computed by SHERPA, which matches the next-to-leading order matrix elements with contributions of parton showers, whereas the massive quark traversing the quark-gluon plasma is described by a Monte Carlo model, SHELL, which can simultaneously simulate light and heavy flavor in-medium energy loss within the framework of Langevin evolution. In p+p collisions, we find that at lower

the radial profiles of heavy flavors in jets are sensitive to the heavy quark mass. In 0-10% Pb+Pb collisions at

TeV, we observe an inverse modification pattern of the B meson radial profiles in jets at

GeV compared to those of D mesons: the jet quenching effects narrow the jet radial profiles of B mesons in jets while broadening those of D mesons in jets. We find that in A+A collisions, the contribution dissipated from the higher

GeV region naturally has a narrower initial distribution and consequently leads to a narrower modification pattern of the radial profile; however the diffusion nature of the heavy flavor in-medium interactions will give rise to a broader modification pattern of the radial profile. These two effects consequently compete and offset with each other, and the b quarks in jets benefit more from the former and suffer less diffusion effect compared to that of c quarks in jets. These findings can be tested in the future experimental measurements at the LHC to gain better understanding of the mass effect of jet quenching.