bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-time feedback system for divertor heat flux control at COMPASS tokamak
Authors: Khodunov I , Komm M , Havranek A , Adamek J , Bohm P , Cavalier J , Seidl J , Devitre A , Dimitrova M , Elmore S , Faitsch M , Hacek P , Havlicek J , Hron M , Imrisek M , Krbec J , Peterka M , Panek R , Samoylov O , Tomes M , Tomova K , Vondracek P , Weinzettl V 
Published: March 2021

Abstract
The reduction of the incident heat flux onto the divertor will be a necessity for the future thermonuclear reactors. Impurity seeding is recognized as an efficient way to achieve the partial detachment regime, which allows to dissipate a large fraction of power flux by radiation. This paper presents a heat flux real-time feedback system (RTFS) based on impurity seeding controlled by a combined ball-pen and Langmuir probe divertor array in the COMPASS tokamak. A number of features of the system have been studied, such as the type of impurity, seeding location, constants used in the real-time controller and the diagnostic selections. A detailed description of the designed RTFS and the results of the implementation are presented. The findings confirm the applicability of the RTFS for reduction and control of the divertor heat fluxes. Another important implication of this research is the ability of installing such systems in next-step devices.
The minimal seesaw and leptogenesis models
Authors: Xing Zhi-zhong , Zhao Zhen-hua 
Published: March 2021

Abstract
Given its briefness and predictability, the minimal seesaw—a simplified version of the canonical seesaw mechanism with only two right-handed neutrino fields—has been studied in depth and from many perspectives, and now it is being pushed close to a position of directly facing experimental tests. This article is intended to provide an up-to-date review of various phenomenological aspects of the minimal seesaw and its associated leptogenesis mechanism in neutrino physics and cosmology. Our focus is on possible flavor structures of such benchmark seesaw and leptogenesis scenarios and confronting their predictions with current neutrino oscillation data and cosmological observations. In this connection particular attention will be paid to the topics of lepton number violation, lepton flavor violation, discrete flavor symmetries, CP violation and antimatter of the Universe.
Performance analysis of surface plasmon resonance sensors using bimetallic alloy-perovskite-bimetallic alloy and perovskite-bimetallic alloy-perovskite nanostructures
Authors: Dhibi Abdelhak , Hakami Jabir , Abassi Amel 
Published: March 2021

Abstract
In this paper, four SPR sensors have been proposed and analyzed theoretically. The proposed SPR sensors are prism—Au-Ag alloy—CH3NH3PbI3—Au-Ag alloy—graphene—sensing medium, prism—Au-Al alloy—CH3NH3PbI3—Au-Al alloy—graphene—sensing medium, prism—CH3NH3PbI3—Au-Ag alloy—CH3NH3PbI3—graphene—sensing medium and prism—CH3NH3PbI3—Au-Al alloy—CH3NH3PbI3—graphene—sensing medium. Matrix method for N-layer model has been utilized to analysis the performance parameters of the proposed sensors. The performance parameters were determined in terms of the detection accuracy (DA), sensitivity, and figure of Merit (FoM). The thicknesses of bimetallic alloy and CH3NH3PbI3 layers and bimetallic alloy composition have been optimized to achieve the best performance of the sensors. It is found that the best detection accuracy, sensitivity and figure of Merit of the proposed sensors are 0.279 deg−1, 85.2 deg/RIU and 23.79 RIU−1 for configuration I; 0.414 deg−1, 77.2 deg/RIU and 32.03 RIU−1 for configuration II; 0.120 deg−1, 106.60 deg/RIU and 12.81 RIU−1 for configuration III; and 0.186 deg−1, 93 deg/RIU and 17.35 RIU−1 for configuration IV.
Effect of Y-doped NbB2.5 on structural and superconducting properties
Authors: Arévalo-López E P , Rosas-Huerta J L , Huerta L , Marquina M L , Romero M , Escamilla R 
Published: March 2021

Abstract
The crystal structure and magnetic properties of Nb1−xYxB2.5 with 0.000 ≤ x ≤ 0.050 compositions are reported. Rietveld refinement of XRD patterns shows that the partial substitution with yttrium atoms in niobium sites increases the unit cell volume. Magnetization measurements show that the critical temperature (T

c
) changes from 9.0 K to 9.9 K for x = 0.000 and x = 0.050, respectively. Using the XPS measurements, the Nb 3d and B 1s core levels were identified, and the XPS valence band of XPS was measured. Our results show an increase in the valence band at zero eV as the yttrium content increases, which might be related to the T

c
change. The electron-phonon coupling constant was calculated from the McMillan equation; our results indicate that the Nb1−xYxB2.5 compounds are weak-coupled superconductors. Our work stablishes the effect of light doping on the structure and physical properties of these superconductors.
Experimental studies on photoabsorption by endohedral fullerene ions with a focus on Xe@C60
+ confinement resonances
Authors: Müller A , L D Kilcoyne A , Schippers S , A Phaneuf R 
Published: March 2021

Abstract
A brief overview on the status of experimental investigations into photoionization and fragmentation of fullerenes and endohedral fullerenes by absorption of a single short-wavelength photon is presented. The focus of this paper is on the endohedral Xe@C60
+ molecular ion in which a xenon atom is centrally encapsulated inside a

C

60

+

fullerene cage. Confinement resonances that result from the interference of Xe photoelectron matter waves emerging from the

C

60

+

cavity were studied by exposing Xe@C60
+ ions to synchrotron radiation of 60 to 150 eV energy which is the region of the well-known giant atomic Xe

4
d

excitation resonance. Photoions Xe@C
n

q+ (with final charge states

q
=
2
,
3
,
4

of the product ions and numbers

n
=
60
,
58
,
56
,
54

of carbon atoms left in the cage) were recorded as a function of photon energy and cross sections for the individual reaction channels were determined. In addition to previous work, new final channels (

q
=
2
;
n
=
60
,
58

and

q
=
4
;
n
=
58
,
56

) were observed, and thus, about 70% of the oscillator strength expected for the encapsulated Xe atom in the investigated energy range could be recovered. The present results establish the first and, so far, only conclusive experimental observation of confinement resonances in an endohedral fullerene. The data are in remarkable agreement with relativistic R-matrix calculations that accompanied the previous experimental work.
Retrograde polish doughnuts around boson stars
Authors: Teodoro Matheus C. , Collodel Lucas G. , Kunz Jutta 
Published: March 2021

Abstract
We investigate polish doughnuts with a uniform constant specific angular momentum distribution in the space-times of rotating boson stars. In such space-times thick tori can exhibit unique features not present in Kerr space-times. For instance, in the context of retrograde tori, they may possess two centers connected or not by a cusp. Rotating boson stars also feature a static ring, neither present in Kerr space-times. This static ring consists of static orbits, where particles are at rest with respect to a zero angular momentum observer at infinity. Here we show that the presence of a static ring allows for an associated static surface of a retrograde thick torus, where inside the static surface the fluid moves in prograde direction. We classify the retrograde Polish doughnuts and present several specific examples.
Gravitational dark matter production in Palatini preheating
Authors: Karam Alexandros , Raidal Martti , Tomberg Eemeli 
Published: March 2021

Abstract
We study preheating in plateau inflation in the Palatini
formulation of general relativity, in a special case that resembles
Higgs inflation. It was previously shown that the oscillating
inflaton field returns to the plateau repeatedly in this model, and
this leads to tachyonic production of inflaton particles. We show
that a minimally coupled spectator scalar field can be produced even
more efficiently by a similar mechanism. The mechanism is purely
gravitational, and the scalar field mass can be of order
1013 GeV, larger than the Hubble scale by many orders of
magnitude, making this a candidate for superheavy dark matter.
Notch fatigue of Cu50Zr50 metallic glasses under cyclic loading: molecular dynamics simulations
Authors: Yang Yong , Li Hairui , Yang Zailin , Liu Jin , Kabutey Kateye Evans , Zhao Jianwei 
Published: March 2021

Abstract
Molecular dynamics simulation is performed to simulate the tension–compression fatigue of notched metallic glasses (MGs), and the notch effect of MGs is explored. The notches will accelerate the accumulation of shear transition zones, leading to faster shear banding around the notches’ root causing it to undergo severe plastic deformation. Furthermore, a qualitative investigation of the notched MGs demonstrates that fatigue life gradually becomes shorter with the increase in sharpness until it reaches a critical scale. The fatigue performance of blunt notches is stronger than that of sharp notches. Making the notches blunter can improve the fatigue life of MGs.
Orbital period correction and light curve modeling of the W-subtype shallow contact binary OW Leo
Authors: Zhou Xiao , Qian Sheng-Bang 
Published: March 2021

Abstract
Orbital period and multi-color light curves′ investigation of OW Leo are presented for the first time. The orbital period of OW Leo is corrected from P = 0.325545 days to P = 0.32554052 days in our work, and the observational data from the All-Sky Automated Survey for SuperNovae (ASAS-SN) are used to test the newly determined orbital period. Then, the phased light curves are calculated with the new period and the Wilson-Devinney program is applied to model the light curves, which reveal that OW Leo is a W-subtype shallow contact binary system (q = 3.05, f = 12.8 %). The absolute physical parameters of the two component stars are estimated to be M
1 = 0.31(1)M
⊙, M
2 = 0.95(3)M
⊙, R
1 = 0.63(1)R
⊙, R
2 = 1.04(1)R
⊙, L
1 = 0.43(1)L
⊙ and L
2 = 1.01(2)L
⊙. The evolutionary status shows that the more massive star is less evolved than the less massive star. OW Leo has very low metal abundance, which means its formation and evolution are hardly influenced by any additional component. It is formed from an initially detached binary system through nuclear evolution and angular momentum loss via magnetic braking, and has passed a very long time of main sequence evolution.
Seamless maps of major elements of the Moon: Results from high-resolution geostationary satellite
Authors: Lu Yu , Wu Yun-Zhao , Li Cui , Ma Jin-Song , Qi Wen-Wen , Tan Wei , Li Xiao-Man , Shi Zhi-Cheng , He Hong-Yan , Dai Shu-Wu , Li Guo , Liu Feng-Jing , Wang Jing-Qiao , Wang Xiao-Yan , Wang Qi , Meng Ling-Jie 
Published: March 2021

Abstract
Major elements such as Fe, Ti, Mg, Al, Ca and Si play very important roles in understanding the origin and evolution of the Moon. Previous maps of these major elements derived from orbital data are based on mosaic images or low-resolution gamma-ray data. The hue variations and gaps among orbital boundaries in the mosaic images are not conducive to geological studies. This paper aims to produce seamless and homogenous distribution maps of major elements using the single-exposure image of the whole lunar disk obtained by China’s high-resolution geostationary satellite, Gaofen-4, with a spatial resolution of ∼ 500 m. The elemental contents of soil samples returned by Apollo and Luna missions are regarded as ground truth, and are correlated with the reflectance of the sampling sites extracted from Gaofen-4 data. The final distribution maps of these major oxides are generated with the statistical regression model. With these products, the average contents and proportions of the major elements for maria and highlands were estimated and compared. The results showed that SiO2 and TiO2 have the highest and lowest fractions in mare and highland areas, respectively. Moreover, the relative concentrations of these elements could serve as indicators of geologic processes, e.g., the obviously asymmetric distributions of Al2O3, CaO and SiO2 around Tycho crater may suggest that Tycho crater was formed by an oblique impact from the southwest direction.
The conformity of H i galaxies in ALFALFA-SDSS sample
Authors: Li Lin-Cheng , Qin Bo , Wang Jie , Wang Jing , Wang You-Gang 
Published: March 2021

Abstract
The conformity effect, indicating the evolution of galaxies is related to its surrounding neighbor galaxies as far as a few Mpc, is an interesting phenomenon in the modeling of galaxy and evolution. Here we study the conformity effect of HI galaxies in a matched galaxy sample between SDSS DR7 and ALFALFA surveys. By checking the probability difference for the detected H i galaxies as a function of distance around a normal or an H i galaxy, we find that this effect is significant out to 5 Mpc. It also shows a dependence on the stellar mass of galaxies, with the strength the strongest in the stellar mass range of 1010 < M
*/M⊙ < 1010.5. However, when the sample is confined to central galaxies in groups with virial radii smaller than 1 Mpc, the 1-halo conformity signal is still evident, while the 2-halo conformity signal is reduced to a very weak amplitude. Our results confirm the previous study in the optical band that the 2-halo term is possibly caused by the bias effect in the sample selection. Furthermore, we confirm the existence of the 1-halo conformity discovered in the optical and radio band in previous investigations. Our results provide another viewpoint on the conformity effect and hope to shed light on the co-evolution of the galaxies and their neighbors in the current galaxy formation models.
Numerically investigating the peculiar periphery of a supernova remnant in the medium with a density gradient: the case of RCW 103
Authors: Lu Chun-Yan , Yan Jing-Wen , Wen Lu , Fang Jun 
Published: March 2021

Abstract
The young shell-type supernova remnant RCW 103 has peculiar properties in the X-ray morphology obtained with Chandra. The southeastern shell is brighter in the X-rays, and the curved border of the shell in this region is flatter than the other part.We investigate the formation of the peculiar periphery of the supernova remnant RCW 103 using 3D hydrodynamical simulation. Assuming that the supernova ejecta has been evolved in the medium with a density gradient, the detected shape of the periphery can be generally reproduced. For RCW 103, with the ejecta mass of 3.0 M
⊙, the density of the background material of 2.0 cm−3, and a gradient of 3.3 − 4.0 cm−3 pc−1, the X-ray periphery can be generally reproduced. The simulation turned out that the asymmetry of the SNR RCW 103 is mainly due to the inhomogeneous medium with a density gradient.
Can we constrain the evolution of HI bias using configuration entropy?
Authors: Das Biswajit , Pandey Biswajit 
Published: March 2021

Abstract
We study the evolution of the configuration entropy of HI distribution in the post-reionization era assuming different time evolution of HI bias. We describe time evolution of linear bias of HI distribution using a simple form b(a) = b
0
an
with different index n. The derivative of the configuration entropy rate is known to exhibit a peak at the scale factor corresponding to the Λ-matter equality in the unbiased ΛCDM model. We show that in the ΛCDM model with time-dependent linear bias, the peak shifts to smaller scale factors for negative values of n. This is related to the fact that the growth of structures in the HI density field can significantly slow down even before the onset of Λ domination in the presence of a strong time evolution of the HI bias. We find that the shift is linearly related to the index n. We obtain the best fit relation between these two parameters and propose that identifying the location of this peak from observations would allow us to constrain the time evolution of HI bias within the framework of the ΛCDM model.
Searching for r-process-enhanced stars in the LAMOST survey I: the method
Authors: Chen Tian-Yi , Shi Jian-Rong , Beers Timothy C. , Yan Hong-Liang , Gao Qi , Li Chun-Qian , Li Hai-Ning , Zhao Gang 
Published: March 2021

Abstract
The abundance patterns of r-process-enhanced stars contain key information required to constrain the astrophysical site(s) of r-process nucleosynthesis, and to deepen our understanding of the chemical evolution of our Galaxy. To expand the sample of known r-process-enhanced stars, we have developed a method to search for candidates in the LAMOST medium-resolution (R ∼ 7500) spectroscopic survey by matching the observed spectra to synthetic templates around the Eu ii line at 6645.1 Å. We obtain a sample of 13 metal-poor (−2.35 < [Fe/H] < −0.91) candidates from 12 209 unique stars with 32 774 mediumresolution spectra. These candidates will be further studied by high-resolution follow-up observations in the near future. We describe some extensions of this effort to include larger samples of stars, in particular at lower metallicity, using the strength of the Ba ii line at 6496.9 Å.
The optimization of satellite orbit for Space-VLBI observation
Authors: Liu Lei , Zheng Wei-Min 
Published: March 2021

Abstract
By sending one or more telescopes into space, Space-VLBI (SVLBI) is able to achieve even higher angular resolution and is therefore the trend of the VLBI technique. For the SVLBI program, the design of satellite orbits plays an important role for the success of planned observation. In this paper, we present our orbit optimization scheme, so as to facilitate the design of satellite orbits for SVLBI observation. To achieve that, we characterize the uv coverage with a measure index and minimize it by finding out the corresponding orbit configuration. In this way, the design of satellite orbit is converted to an optimization problem. We can prove that, with an appropriate global minimization method, the best orbit configuration can be found within the reasonable time. Besides that, we demonstrate that this scheme can be used for the scheduling of SVLBI observations.
On the encounter desorption of hydrogen atoms on an ice mantle
Authors: Chang Qiang , Zheng Xu-Li , Zhang Xia , Quan Dong-Hui , Lu Yang , Meng Qing-Kuan , Li Xiao-Hu , Chen Long-Fei 
Published: March 2021

Abstract
At low temperatures (∼10 K), hydrogen atoms can diffuse quickly on grain ice mantles and frequently encounter hydrogen molecules, which cover a notable fraction of grain surface. The desorption energy of H atoms on H2 substrates is much less than that on water ice. The H atom encounter desorption mechanism is adopted to study the enhanced desorption of H atoms on H2 substrates. Using a small reaction network, we show that the steady-state surface H abundances predicted by the rate equation model that includes H atom encounter desorption agree reasonably well with the results from the more rigorous microscopic Monte Carlo method. For a full gas-grain model, H atom encounter desorption can reduce surface H abundances. Therefore, if a model adopts the encounter desorption of H atoms, it becomes more difficult for hydrogenation products such as methanol to form, but it is easier for C, O and N atoms to bond with each other on grain surfaces.
A new telescope with three fields of view to measure the orientation parameters of the Moon and terrestrial planets
Authors: Sun Li-Zao , Huang Cheng-Li , Yu Yong , Qi Zhao-Xiang , Tang Zheng-Hong , Zhao Ming , Yang De-Hua , Wu Tong 
Published: March 2021

Abstract
For lots of scientific questions about lunar physics deep inside the Moon, in-situ observation on lunar physical libration is one of the most potential ways. In this paper, we propose a brand new optical telescope functioned with simultaneously observing multiple (here there are three) fields of view (FOVs) for in-situ observation of lunar physical libration. The telescope can be placed at any place with any attitude on the Moon and do not require manned install, control or operation. It passively, continuously and simultaneously observe stars in three FOVs along with rotation of the Moon. Libration is to be measured and studied from celestial motion of the directions of three FOVs from image processing. The concept and design of this telescope are firstly introduced in this paper. The principle and feasibility of the method of in-situ observation are also demonstrated. From simulation, precision of the determined lunar physical libration is expected to be several milliarcsecs, about two orders of magnitude better than the current precision of libration by lunar laser ranging observation. Libration data with milliarcsec precision level can play a valuable role in the study of the physics and dynamics of the interior of the Moon. This telescope can also be applied to observe the rotation of other terrestrial planets like Mars.
Spin-down and emission variations for PSR J0742−2822
Authors: Dang Shi-Jun , Wang Na , Wang Hui-Hui , Yuan Jian-Ping , Shang Lun-Hua , Yuen Rai , Ge Ming-Yu , Zhou Xia , Wang Shuang-Qiang , Kou Fei-Fei , Yan Wen-Ming , Wang Jing-Bo , Wen Zhi-Gang , Bai Jun-Tao , Liu Zhi-Yong , Zhou Zu-Rong 
Published: March 2021

Abstract
PSR J0742−2822 is known for its quasi-periodic changes in the observed pulse profile and spindown rate. In this paper, we analyzed 13 years of timing data obtained with the Nanshan 25-m radio telescope and the Parkes 64-m radio telescope. We found that the average values of the spin-down rate (

〈

ν
˙

〉

) of this pulsar changed in four different states. We investigated the correlation between

ν
˙

and W
50, and ascertained that the correlation changed in different

〈

ν
˙

〉

states. Moreover, not all the changes in

〈

ν
˙

〉

states and correlation can be associated with glitch activities. We examined the long term evolution of γ-ray flux (0.1–300 GeV) and the pulse profiles corresponding to the four different states using Fermi-LAT Pass 8 (P8R3) data from 2008 August 5 to 2019 October 1. We did not detect a significant change in γ-ray flux or the pulse profile. Our results suggest that the connection between pulsar rotation and emission is more complex than previously reported for this pulsar.
Anomalies in Young's modulus behavior after annealing in polycrystalline SmS
Authors: Kaminskii V. V. , Sharenkova N. V. , Kamenskaya G. A. , Grevtsev M. A. , Lyubimova Yu. V. 
Published: March 2021

Abstract
In this paper, the dependencies of Young's modulus and attenuation decrement on samarium sulfide polycrystals (SmS) under various annealing temperatures are studied by the piezoelectric ultrasonic composite oscillator technique at a frequency of 100 kHz in the temperature range of 80–300 K. A decrease in Young's modulus with an increase of the annealing temperature due to the texturing of the material was revealed. At the same time, attenuation peaks were observed at temperatures about 90 and 125 K, presumably due to Niblett-Wilks and Bordoni relaxations.
A 1.2 V, 3.1% 3σ-accuracy thermal sensor analog front-end circuit in 12 nm CMOS process
Authors: Yang Liqiong , Wang Linfeng , Xiao Junhua , Zhang Longbing , Wang Jian 
Published: March 2021

Abstract
This paper presents a 1.2 V high accuracy thermal sensor analog front-end circuit with 7 probes placed around the microprocessor chip. This analog front-end consists of a BGR (bandgap reference), a DEM (dynamic element matching) control, and probes. The BGR generates the voltages linear changed with temperature, which are followed by the data read out circuits. The superior accuracy of the BGR’s output voltage is a key factor for sensors fabricated via the FinFET digital process. Here, a 4-stage folded current bias structure is proposed, to increase DC accuracy and confer immunity against FinFET process variation due to limited device length and low current bias. At the same time, DEM is also adopted, so as to filter out current branch mismatches. Having been fabricated via a 12 nm FinFET CMOS process, 200 chips were tested. The measurement results demonstrate that these analog front-end circuits can work steadily below 1.2 V, and a less than 3.1% 3σ-accuracy level is achieved. Temperature stability is 0.088 mV/°C across a range from –40 to 130 °C.