bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detailed band alignment of high-B-composition BGaN with GaN and AlN
Authors: AlQatari F , Liao C-H , Aguileta-Vazquez R R , Tang X , Lopatin S , Li X 
Published: June 2023

Abstract
The electronic structure of B0.097Ga0.903N was determined by examining its bandgap and valence band offset (VBO) in detail. The BGaN sample was grown using a horizontal reactor metalorganic chemical vapor deposition. For bandgap determination, three different techniques were utilized yielding similar results, which are: UV–Vis spectroscopy, Schottky photodiodes, and electron energy-loss spectroscopy. The bandgap was determined to be ∼3.55 eV. For measuring the VBO, the valence edges and the core levels of Al 2s and Ga 2p were measured using x-ray photoelectron spectroscopy (XPS). The valence edges were then fitted and processed along with the core levels using the standard Kraut method for VBO determination with AlN. The BGaN/AlN alignment was found to be −1.1 ± 0.1 eV. Due to core level interference between GaN and BGaN, the Kraut method fails to provide precise VBO for this heterojunction. Therefore, a different technique is devised to analyze the measured XPS data which utilizes the alignment of the Fermi levels of the BGaN and GaN layers when in contact. Statistical analysis was used to determine the BGaN/GaN alignment with decent precision. The value was found to be −0.3 ± 0.1 eV.
Spin-liquid state with precursor ferromagnetic clusters interacting antiferromagnetically in frustrated glassy tetragonal spinel Zn0.8Cu0.2FeMnO4
Authors: Jena S K , Seehra M S , Sarkar T , Reehuis M , Hoser A , Weise B , Thota S 
Published: June 2023

Abstract
Spinels (AB
2O4) with magnetic ions occupying only the octahedral B sites have inherent magnetic frustration which inhibits magnetic long-range order (LRO) but may lead to exotic states. Here we report on the magnetic properties of the tetragonal spinel Zn0.8Cu0.2FeMnO4, the tetragonality resulting from the Jahn–Teller active Mn3+ ions. X-ray diffraction and x-ray photoelectron spectroscopy of the sample yielded the composition (

Zn

0.8

2
+

Cu

0.2

2
+

)
A
[

Fe

0.4

2
+

Fe

0.6

3
+

M

n

3
+

]
B
O4‒δ
. Analysis of the temperature dependence of magnetization (M), ac magnetic susceptibilities (χ′ and χ′′), dc susceptibility (χ), heat capacity Cp
, and neutron diffraction (ND) measurements show complex temperature-dependent short-range order (SRO) but without LRO. The data of χ vs. T fits the Curie–Weiss law: χ = C/(T ‒ θ) from T = 250 K to 400 K with θ ≃ 185 K signifying dominant ferromagnetic (FM) coupling with the FM exchange constant J/k
B = 17 K, and C = 3.29 emu K mol‒1 Oe‒1 yielding an effective magnetic moment µ
eff = 5.13 µ
B resulting from the high-spin states of Cu2+ (A site) and Fe2+ (B site), while the B site trivalent ions Mn3+ and Fe3+ are in their low-spin states. The extrapolated saturation magnetization obtained from the M vs. H data at T = 2 K is explained using the spin arrangement (Cu2+↓)
A
[Fe2+↑, Fe3+↓, Mn3+↑]
B
leading to FM clusters interact antiferromagnetically at low temperatures. Temperature dependence of d(χT)/dT shows the onset of ferrimagnetism below ∼100 K and peaks near 47 K and 24 K. The relaxation time τ obtained from temperature and frequency dependence of χ″ when fit to the power law and Vogel–Fulcher laws confirm the cluster spin-glass (SG) state. The magnetic field dependence of the SG temperature

T

SG

H

follows the equation:

T

SG

H

=

T

SG

0

1
−
A

H

2

/

ϕ

with T
SG (0) = 46.6 K, A = 8.6 × 10‒3 Oe‒0.593 and

ϕ

= 3.37. The temperature dependence of hysteresis loops yields coercivity HC
∼ 3.8 kOe at 2 K without exchange-bias, but HC
decreases with increase in T becoming zero above 24 K, the T
SG(H) for H = 800 Oe. Variations of Cp vs. T from 2 K to 200 K in H
= 0 and H
= 90 kOe do not show any peak characteristic of LRO. However, after correcting for the lattice contribution, a broad weak peak typically of SRO becomes evident centered around 40 K. For T < 9 K, Cp
varies as T2
; a typical signature of spin-liquids (SLs). Comparison of the ND measurements at 1.7 K and 79.4 K shows absence of LRO. Time dependence of thermo-remanent magnetization M
TRM(t) studies below 9 K reveal weakening of the inter-cluster interaction with increase in temperature. A summary of these results is that in Zn0.8Cu0.2FeMnO4, ferromagnetic clusters interact antiferromagnetically without LRO but producing a cluster SG state at T
SG(0) = 46.6 K, followed by SL behavior below 9 K.
Controllable resistive switching behaviors in heteroepitaxial LaNiO3/Nb:SrTiO3 Schottky junctions through oxygen vacancies engineering
Authors: Zhang Yong , Gao Shunhua , Cao Guiming , Ma Chunrui , Nan Hu , Liu Ming 
Published: June 2023

Abstract
Perovskite oxide-based memristors have been extensively investigated for the application of non-volatile memories, and the oxygen vacancies associated with Schottky barrier changing are considered as the origin of the memristive behaviors. However, due to the difference of device fabrication progress, various resistive switching (RS) behaviors have been observed even in one device, deteriorating the stability and reproducibility of devices. Precisely controlling the oxygen vacancies distribution and shedding light on the behind physic mechanism of these RS behaviors, are highly desired to help improve the performance and stability of such Schottky junction-based memristors. In this work, the epitaxial LaNiO3 (LNO)/Nb:SrTiO3 (NSTO) is adopted to explore the influence of oxygen vacancy profiles on these abundant RS phenomena. It demonstrates that the migration of oxygen vacancy in LNO films plays a key role in memristive behaviors. When the effect of oxygen vacancies at the LNO/NSTO interface is negligible, improving the oxygen vacancies concentration in LNO film could facilitate resistance on/off ratio of HRS and LRS, and the corresponding conducting mechanisms attributes to the thermionic emission and tunneling-assisted thermionic emission, respectively. Moreover, it is found that reasonably increasing the oxygen vacancies at LNO/NSTO interface makes trap-assisted tunneling possible, also providing an effective way to improve the performance of the device. The results in this work have clearly elucidated the relationship between oxygen vacancy profile and RS behaviors, and give physical insights into the strategies for improving the device performance of Schottky junction-based memristors.
Positive solutions of the Gross–Pitaevskii equation for energy critical and supercritical nonlinearities
Authors: Pelinovsky Dmitry E , Wei Juncheng , Wu Yuanze 
Published: June 2023

Abstract
We consider positive and spatially decaying solutions to the following Gross–Pitaevskii equation with a harmonic potential:

−
Δ
u
+

|

x

|

2

u
=
ω
u
+

|

u

|

p
−
2

u

in

R

d

,

where

d
⩾
3

, p > 2 and ω > 0. For

p
=

2
d

d
−
2

(energy-critical case) there exists a ground state u

ω
if and only if

ω
∈
(

ω
∗

,
d
)

, where

ω
∗

=
1

for d = 3 and

ω
∗

=
0

for

d
⩾
4

. We give a precise description on asymptotic behaviours of u

ω
as

ω
→

ω
∗

up to the leading order term for different values of

d
⩾
3

. When

p
>

2
d

d
−
2

(energy-supercritical case) there exists a singular solution

u
∞

for some

ω
∈
(
0
,
d
)

. We compute the Morse index of

u
∞

in the class of radial functions and show that the Morse index of

u
∞

is infinite in the oscillatory case, is equal to 1 or 2 in the monotone case for p not large enough and is equal to 1 in the monotone case for p sufficiently large.
Experimental and numerical investigation of surface streamers in a nanosecond pulsed packed bed reactor
Authors: Li Mengbo , Chen She , Zhu Yifei , Li Yunjie , Wang Feng , Cui Yingzhe , Zhuang Chijie 
Published: June 2023

Abstract
Packed bed reactor (PBR) is the commonly used configuration in plasma catalysis, and its plasma characteristics have been extensively investigated. The filled catalysts in PBR make it challenging to carry out in-situ measurements of electric fields, and limited experimental data have been obtained. We investigated the surface streamer propagation and electric field distribution in a simplified PBR through simulations and experiments. The simplified PBR in the experiments is comprised of a blade-plate electrode structure filled with an Al2O3 column (ϵr
= 9) in the discharge gap. An ICCD camera and an electric field diagnosis method called EFISH (electric field induced second harmonic generation) were employed, and a two-dimensional fluid model was established for the simulation. Four discharge types in the PBR were identified based on ICCD images and simulation results, including polar discharge at the contact areas, surface streamer along the dielectric column, expansion of surface discharge along the dielectric column, and surface ionization waves along the dielectric plate. Surface streamers with opposite propagation directions were found in the model, namely the forward streamer during the pulse rising time and the reverse streamer during the pulse falling time. Notably, the reverse streamer exhibits a significantly lower velocity compared to the forward streamer. Both experimental measurements and simulation were conducted to investigate the spatiotemporal electric field near the surface of the packing material. The results of both E
exp and E
sim showed peaks with opposite polarities, and exhibited similar trends. In the simulation, the forward streamer head showed a higher electric field compared to the reverse streamer head. Moreover, during the rest pulse time, the surface electric field was more intense at the contact areas than in other regions. The findings of this work provide valuable insights into the discharge mechanism and electric field on the catalytic material surface within the PBR.
A comparison of template vs. direct model fitting for redshift-space distortions in BOSS
Authors: Maus Mark , Chen Shi-Fan , White Martin 
Published: June 2023

Abstract
The growth of large-scale structure, as revealed in the anisotropic of clustering of
galaxies in the low redshift Universe at z < 2, provides a stringent test of our
cosmological model. The strongest current constraints come from the BOSS and eBOSS surveys, with
uncertainties on σ
8, the amplitude of clustering on an 8 h
-1Mpc scale, of
less than 10 per cent. A number of different approaches have been taken to fitting this signal,
leading to discrepancies of up to 1σ in the measurements of the amplitude of
fluctuations at late times. We compare in some detail two of the leading approaches, one based on
fitting a template cosmology whose amplitude and length scales are allowed to float with one based
on varying the underlying parameters of a cosmological model directly, when fitting to
the BOSS DR12 data. Holding the input data, scale cuts, window functions and modeling framework
fixed we are able to isolate the cause of the differences and discuss the implications for future
surveys.
Pinning down the primordial black hole formation mechanism with gamma-rays and gravitational waves
Authors: Xie Ke-Pan 
Published: June 2023

Abstract
Primordial black holes (PBHs) are predicted in many models via different formation mechanisms. Identifying the origin of PBHs is of the same importance as probing their existence. We propose to probe the asteroid-mass PBHs [𝒪(1017) g ≲ M ≲ 𝒪 (1022) g] with gamma-rays from Hawking radiation and the stochastic gravitational waves (GWs) from the early Universe. We consider four concrete formation mechanisms, including collapse from primordial curvature perturbations, first-order phase transitions, or cosmic strings, and derive the extended PBH mass functions of each mechanism for phenomenological study. The results demonstrate that by combining gamma-rays and GW signals we can probe PBHs up to 𝒪(1019) g and identify their physical origins.
The Design, Verification, and Performance of the James Webb Space Telescope
Authors: Menzel M. , Davis M. , Parrish K. , Lawrence J. , Stewart A. , Cooper J. , Irish S. , Mosier G. , Levine M. , Pitman J. , Walsh G. , Maghami P. , Thomson S. , Wooldridge E. , Boucarut R. , Feinberg L. , Turner G. , Kalia P. , Bowers C. 
Published: June 2023

Abstract
The James Webb Space Telescope (JWST) is NASA’s flagship mission successor to the highly successful Hubble Space Telescope. It is an infrared observatory featuring a cryogenic 6.6 m aperture, deployable Optical Telescope Element (OTE) with a payload of four science instruments (SIs) assembled into an Integrated Science Instrument Module (ISIM) that provide imagery and spectroscopy in the near-infrared band between 0.6 and 5 μm and in the mid-infrared band between 5 and 28.1 μm. JWST was successfully launched on 2021 December 25 aboard an Ariane 5 launch vehicle. All 50 major deployments were successfully completed on 2022 January 8. The observatory performed all midcourse correction maneuvers and achieved its operational mission orbit around the Sun–Earth second Lagrange point (L2). All commissioning and calibration activities have been completed, and JWST has begun its science mission. This paper will provide a description of the driving requirements and their technical challenges, the engineering processes involved in the design formulation, the resulting observatory design, the verification programs that proved it to be flightworthy, and the measured on-orbit performance of the observatory. Since companion papers will describe the details of the OTE and SIs, this paper will concentrate on describing the key features of the observatory architecture that accommodates these elements, particularly those features and capabilities associated with accommodating the radiometric and image-quality performance.
Intelligent Medical Knowledge Robot Based on Knowledge Graph
Authors: Li Jingyu , Han Mingxu , Dong Guangyu , Wei Huimei , Li Yao 
Published: June 2023

Abstract
Artificial intelligence has been gradually integrated into life, and knowledge graph is also particularly important, and its application is gradually maturing. In recent years researchers have used the rich entity and relationship information in the knowledge graph to overcome many difficulties. Through the fusion, reasoning, and deep learning of large-scale knowledge graphs, knowledge graphs link and apply these memories to generate wisdom. It can be said that knowledge graph has become the infrastructure of the era of artificial intelligence. The article combines Neo4j with ECharts visualization to develop a visual question answering robot in the medical field. This uses a more scientific method to understand and present data, provides a humanized visual question answering robot. And finally shows the effect of visual knowledge graph as well as assists users in the analysis of specific diseases.
Remote Laboratory Experiments: Fan Map Generation and Airfoil Flow Characterization
Authors: Eleftheriou K , Efstathiadis T , Kalfas A I 
Published: June 2023

Abstract
This paper presents the procedure followed to conduct two various experiments as part of the ‘Mechanical Laboratory’ course of the Mechanical Engineering department, at Aristotle University of Thessaloniki, during the Covid-19 period. Adapting to the personal contact restrictions imposed by the health issue outbreak, a remote experimental method is proposed. In the first experiment, the students had to generate the operational map of a cooling computer fan while on the second one the characteristic parameters of a symmetric airfoil needed to be measured. Multifunctional control panel interfaces were introduced to the students. Through these applications, the student had the opportunity to run the experiments, assess the raw data, monitor all the necessary flow parameters and acquire the important variables. The students had to post-process the results and submit two reports, one for each experiment. This teaching method provided the students with the experience of real research project and guided them to use modern tools to enhance the quality of their future work. This publication focuses on the address of the challenges, arose during the automation of the experiments. The remote experimental sessions indicated some advantages in learning procedure which was also reflected on the assignment grades. The development of the procedure has been successfully implemented and tested over a couple of years while the quarantine measure have been in place. Furthermore, the experience gained will be used to implement modern communication protocols in the experimental set-ups.
Laser triangulation measurement of blade oscillation in a transonic compressor cascade
Authors: Šidlof Petr , Šidlof Pavel , Štěpán Martin , Šimurda David , Lepicovsky Jan 
Published: June 2023

Abstract
The paper describes a method for optical measurement of oscillation of blades in a linear cascade designed for flutter research. The method uses laser triangulation, which measures the distance between the sensor and the oscillation object. The distance can be recalculated to angular displacement of the blade. However, the relation is nonlinear due to the curvature of the blade. The nonlinear dependence between the distance and angular displacement is derived and quantified analytically. The paper further analyzes the influence of light refraction in the optical window, surface quality and sensor inclination. A procedure for the nonlinear calibration is proposed and used during wind tunnel measurements in a blade cascade with forced oscillation of the middle blade.
A flow field around a cylindrical probe in proximity to stator blades and its effect on the measurements
Authors: Sedunin V A , Xu L , Kalinin I A , Marchenko I G , Komarov O V 
Published: June 2023

Abstract
In multistage axial compressors of gas turbine engines, there is a need for a detailed understanding of the flow field in between the blade rows, which could be obtained by spanwise traversing. This requires a pneumatic probe to be immersed into the flow path between the blade rows, where the space is limited. Therefore, the probe will affect the flow field around it and in the blade channel, and the probe readings will be affected by that flow field. As a result, these probe readings cannot be translated to flow parameters based on just the freestream calibration characteristics, obtained in the idealized wind tunnel. In our paper, we provide a computational analysis of the flow field around the cylindrical probe in a constrained inter-blade-row environment at different circumferential locations and flow conditions both upstream and downstream of the stator blade row. It is shown that the flow angle measurement error can reach up to five degrees in the mid-pitch locations compared to undistorted flow, and dynamic head measurements can be up to 30% away from the actual mean values of the flow. These deviations are shown to be caused by flow field interaction inside the blade channel and, as a result, measured values, obtained during industrial compressor testing, could be corrected accordingly. The universal correction procedure is proposed for further use in the industry
Inverse design of optical mode converters by topology optimization: tutorial
Authors: Christiansen Rasmus E 
Published: June 2023

Abstract
This tutorial details the use of topology optimization (TopOpt) for the inverse design of electromagnetic mode-converters. First, the design problem under consideration is stated. Second, suitable models for the geometry and physics are formulated and third the TopOpt method is outlined. Then follows three increasingly advanced design examples. In the first, the mode converter is allowed to consist of a non-physically-realizable material distribution, leading to a design exhibiting near perfect conversion from the input mode i to the output mode o in terms of power conversion

, providing a performance benchmark. Then follows two examples demonstrating the imposition of relevant restrictions on the design, first ensuring a physically realizable device blueprint, and second introducing feature-size control and ensuring device connectivity. These examples demonstrate how TopOpt can be used to design device blueprints that only require a minimum of post-processing prior to fabrication, which only incur a minor reduction of performance compared to the initial unconstrained design. A software tool is provided for reproducing the first design example. This tool may be extended to implement the other design examples in the paper, to explore other device configurations or, given sufficient computational resources, to design 3D devices.
Highly doped graphene on ion-exchanged glass
Authors: Graham Christina , Marchena Miriam , Paulillo Bruno , Bhattacharyya Indrani , Mazumder Prantik , Pruneri Valerio 
Published: June 2023

Abstract
Engineering the doping level in graphene is essential to realizing functional electronic and optoelectronic devices. While achieving strong p-doping is relatively straightforward, electrostatic or chemical approaches to negatively dope graphene have yielded electron densities (ns
) of −9.5 × 1012 cm−2 or below. In this work, we demonstrate very high ns
(−1013 to −1014 cm−2) in graphene, on an ion-exchanged glass substrate, which is widely used in touch screen displays (e.g. smart phones). Moreover, the proposed method, which is easy to implement and scalable, leads to relatively stable graphene doping, with about a 40% increase in sheet resistance over 5 months at ambient conditions.
Spatially explicit simulation of deforestation using the Ising-like neutral model
Authors: Stepinski Tomasz F 
Published: June 2023

Abstract
Deforestation is a prominent example of anthropogenic land change. Here we investigate deforestation from a landscape ecology perspective by process-based modeling of a sequence of consecutive landscape patterns starting from a homogeneous forest and ending in homogeneous agricultural land. We propose an Ising-like neutral model to mimic the deforestation dynamics. Our goal is to demonstrate that such a simple conceptualization of the deforestation process is capable of simulating an evolutionary sequence of landscape patterns matching empirical data. The model has only two parameters, one representing an external pressure (for or against deforestation), and another representing a propensity of land for spatial autocorrelation. We perform a suite of simulations to link a process, as parameterized by the values of the two parameters, to the sequence of landscape patterns. We have found a narrow range of parameters for which the model quantitatively and visually matches empirical data. This indicates that the Ising-like neutral model captures the essential aspects of a deforestation process and that the temporal sequence of intermediate landscape patterns does not depend on the details of the process.