bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visible-Light-Driven Selenyl-Radical-Mediated Cascade Spirocyclization of 3-(2-Isocyanobenzyl)indoles with Diselenides
Authors: Qi Lin , Wang Li-Jing , Cao Tong-Yang , Dong Yi-Chen , Cao Jie-Hui 
Published: July 2023

AbstractWe present a facile, visible-light-driven, selenyl-radical-mediated, cascade spirocyclization of 3-(2-isocyanobenzyl)indoles with diselenides that affords various selenylated spiro[indole-3,3′-quinoline] derivatives under mild conditions. This protocol has good functional-group tolerance and a broad substrate scope; both diaryl and dialkyl diselenides are tolerated.
End-of-Life and Palliative Care Issues for Patients Living with Pulmonary Arterial Hypertension: Barriers and Opportunities
Authors: Ali Hyeon-Ju , Sahay Sandeep 
Published: July 2023

AbstractPulmonary arterial hypertension (PAH) is a progressive, incurable disease that results in significant symptom burden, health care utilization, and eventually premature death. Despite the advancements made in treatment and management strategies, survival has remained poor. End-of-life care is a challenging issue in management of PAH, especially when patients are in younger age group. End-of-life care revolves around symptom palliation and reducing psychosocial disease burden for a dying patient and entails advanced care planning that are often challenging. Thus, support from palliative care specialist becomes extremely important in these patients. Early introduction to palliative care in patients with high symptom burden and psychosocial suffering is suggested. Despite of the benefits of an early intervention, palliative care remains underutilized in patients with PAH, and this significantly raises issues around end-of-life care in PAH. In this review, we will discuss the opportunities offered and the existing barriers in addressing high symptom burden and end-of-life care issues. We will focus on the current evidence, identify areas for future research, and provide a call-to-action for better guidance to PAH specialists in making timely, appropriate interventions that can help mitigate end-of-life care issues.
A self-powered human gait monitoring sensor for osteoarthritis prevention
Authors: Ding Yunyi , Luo Yichen , Zhou Xue , Zhang Shaojie , Zhang Bin , Li Yayu 
Published: July 2023

Recently, wearable sensors for human motion posture and medical diagnosis have received widespread attention. However, most wearable sensors rely on a power supply, and their preparation technology still faces limitations. Here, we used eyebrow powder to fabricate a triboelectric nanogenerator (E-TENG) for bio-mechanical energy harvesting and gait monitoring of patients with osteoarthritis. Under a maximum separation distance (5 mm) and a maximum motion frequency (6 Hz), the E-TENG device can attain a open-circuit voltage (Voc) of 169 V and a short-circuit current (Isc) of 5.5 µA. Meanwhile, the maximum output power of the E-TENG can arrive at 175 µW (load resistance: 20 MΩ). The E-TENG can detect human gait patterns (walking, running, and jumping), finger motion, and elbow joint movements. Further research has shown that the E-TENG can be used for gait recognition and monitoring in patients with osteoarthritis, providing reference data for osteoarthritis prevention and treatment. This research can promote the application of TENG devices based on cosmetic materials in medical diagnosis and adjuvant treatment.
Discovery of charge order in a cuprate Mott insulator
Authors: Kang Mingu , Zhang Chao C. , Schierle Enrico , McCoy Stephen , Li Jiarui , Sutarto Ronny , Suter Andreas , Prokscha Thomas , Salman Zaher , Weschke Eugene , Cybart Shane , Wei John Y. T. , Comin Riccardo 
Published: July 2023

Copper oxide superconductors universally exhibit multiple forms of electronically ordered phases that break the native translational symmetry of the CuO
2
planes. In underdoped cuprates with correlated metallic ground states, charge/spin stripes and incommensurate charge density waves (CDWs) have been experimentally observed over the years, while early theoretical studies also predicted the emergence of a Coulomb-frustrated ‘charge crystal’ phase in the very lightly doped, insulating limit of CuO
2
planes. Here, we search for signatures of CDW order in very lightly hole-doped cuprates from the 123 family
R
Ba
2
Cu
3
O

7 −
δ

(
R
BCO;
R
: Y or rare earth), by using resonant X-ray scattering, electron transport, and muon spin rotation measurements to resolve the electronic and magnetic ground states fully. Specifically, Pr is used to substitute Y at the
R
-site to systematically suppress the superconductivity and access the extremely low hole-doping regime of the cuprate phase diagram without changing the oxygen stoichiometry. X-ray scattering data taken on Pr-doped YBCO thin films reveal an in-plane CDW order that follows the same linear evolution of wave vector versus hole concentration as oxygen-underdoped YBCO but extends all the way to the insulating and magnetically ordered Mott limit. Combined with the recent observation of charge crystal phase on an insulating surface of Bi
2
Sr
2
CaCu
2
O

8 +
z

, our results in
R
BCO suggest that this electronic symmetry breaking is universally present in very lightly doped CuO
2
planes. These findings bridge the gap between the Mott insulating state and the underdoped metallic state and underscore the prominent role that Coulomb-frustrated electronic phase separation plays among all cuprates.
Bilevel inverse problems in neuromorphic imaging
Authors: Antil Harbir , Sayre David 
Published: July 2023

Abstract
Event or neuromorphic cameras are novel biologically inspired sensors that record data based on the change in light intensity at each pixel asynchronously. They have a temporal resolution of microseconds. This is useful for scenes with fast moving objects that can cause motion blur in traditional cameras, which record the average light intensity over an exposure time for each pixel synchronously. This paper presents a bilevel inverse problem framework for neuromorphic imaging. Existence of solution to the inverse problem is established. Second order sufficient conditions are derived under special situations for this nonconvex problem. A second order Newton type solver is derived to solve the problem. The efficacy of the approach is shown on several examples.
Edge passivation oxidation-enhanced spin caloritronics in zigzag blue phosphorus nanoribbons
Authors: Xu Jintao , Li Mingjun , Wang Qian , Zhang Xiaojiao , Fei Jiajia , Shi Yuechao , Zhang Bei , Long Meng-Qiu 
Published: July 2023

Abstract
In this study, the spin caloritronics of zigzag blue phosphorus nanoribbons (ZBPNRs) with edge hydrogenation and oxidation were studied using first-principles calculations and the non-equilibrium Green’s function method. Three different cases were considered: two edges of the ZBPNR were oxidized (2O-ZBPNR) and hydrogenated (2H-ZBPNR), one edge was oxidized, and the other was hydrogenated (HO-ZBPNR). Our results show that a perfect thermal spin filtering effect (SFE) and a negative differential thermoelectric resistance (NDTR) can be observed in structures with both 2O-ZBPNR and HO-ZBPNR, whereas these features were not found for 2H-ZBPNR. Furthermore, we confirmed that edge oxygen atoms in ZBPNRs offer different transport pathways for spin-up and spin-down states, leading to thermal SFE, and devices with oxygen-passivated ZBPNRs exhibited strong spin figures of merit (∼38) and large spin Seebeck coefficients (∼9 mV K−1).
State estimation of the dynamic behavior of plasma properties in a Hall effect thruster discharge
Authors: Troyetsky D E , Greve C M , Tsikata S , Hara K 
Published: July 2023

Abstract
The dynamic behaviors of the plasma properties in a Hall effect thruster discharge channel are estimated using a physics-constrained extended Kalman filter (PC-EKF) with a zero-dimensional global plasma model. The state estimates obtained using the global plasma EKF model are augmented by experimental data, in this case a discharge current signal. The use of state estimation allows for the determination of time-resolved plasma behaviors that may be difficult to measure experimentally, such as electron temperature and bulk velocity. The model is applied to investigate the plasma behavior at various thruster operating conditions, i.e. at varying discharge voltages and discharge currents. The estimated plasma properties are used to determine the classical electron collision frequency and the anomalous electron scattering frequency, which are shown to vary in time.
Optical properties of γ-sensing β-GaLaS3:Er crystal
Authors: Halyan V V , Yatcynyuk T K , Yukhymchuk V O , Virko S V , Lyaschuk Yu M , Valakh M Ya , Ivashchenko I A , Lebed O O , Skoryk M A , Litvinchuk A P 
Published: July 2023

Abstract
An erbium-doped β-GaLaS3 crystal has been grown by the solution-melt method, and the effect of γ-irradiation on their vibrational and radiative properties has been investigated. Experiments have demonstrated that the crystal is transparent in the near and mid-infrared (IR) regions (transparency ∼62% in the range of 350–7100 cm−1), which allows it to be used as an effective matrix for creating lasers in this spectral range. For the first time, the vibrational spectrum of the crystal and the density of phonon states have been calculated using the density-functional theory (DFT) method. Both the original and γ-irradiated β-GaLaS3:Er crystals were investigated by Raman and IR spectroscopy. It has been established that irradiation with a dose of up to 5000 Gray does not lead to structural changes in the crystals. The effect of the formed defects is more clearly manifested in the IR reflection spectra, compared to the Raman spectra. The mechanism of the occurrence of excited states and the emission of Er ions embedded in the lattice has been established, and the effect of γ-irradiation on the radiative properties of β-GaLaS3:Er due to the occurrence of radiation-induced defects has been analyzed. A model has been constructed that explains the Stokes and anti-Stokes radiation of the erbium ions in the crystal. It has been demonstrated that the grown crystal has good prospects for sensor and laser technology of the near and mid-IR ranges due to relatively high values of optical transparency and the intense radiative capacity of the erbium ions.
Equal-spin Andreev reflection in antiferromagnet/normal/superconductor junctions with Rashba spin–orbit coupling
Authors: Niu Zhi Ping , Zhang Yong Mei 
Published: July 2023

Abstract
We have theoretically investigated the Andreev reflection (AR)-induced conductance spectra through antiferromagnet/normal layer/superconductor junctions with hexagonal lattices. When the PT symmetry is broken by the staggered sublattice potential, antiferromagnet may exhibit spin polarization. A gap-edge conductance peak is usually shown, reflecting the characteristic of conventional AR. Equal-spin AR can be generated by the spin-flip scattering caused by Rashba spin–orbit coupling in the normal layer. Surprisingly, when the equal-spin AR process dominates, the conductance peak divides into two peaks near the singlet-gap energy, indicating the existence of spin-triplet pairings in the antiferromagnet. Furthermore, as the amplitudes of the conventional and equal-spin ARs can be modulated by the staggered sublattice potential and electrostatic potential, a conversion from the conductance peak to the conductance peak splitting can be realized, which can help us to distinguish between the spin-singlet and spin-triplet pairings. These findings make the antiferromagnet/superconductor junctions as promising platforms for future superconducting spintronics applications.
Rolling bearing fault diagnosis based on multi-scale weighted visibility graph and multi-channel graph convolution network
Authors: Zuo Dong , Tang Tang , Chen Ming 
Published: July 2023

Abstract
Current data-driven fault diagnosis methods are prone to overfitting and a decrease in accuracy when working with only a limited number of labeled samples. Additionally, existing graph neural network-based fault diagnosis methods often fail to comprehensively utilize both global and local features. To address these challenges, we propose a rolling bearing fault diagnosis method based on multi-scale weighted visibility graph and a multi-channel graph convolutional network (MCGCN). Our approach converts vibration signals into multiple weighted graphs from the perspective of geometric meaning and extracts local node feature information and global topology information of graphs using MCGCN. Experimental results demonstrate that our method achieves excellent performance under both sufficient and limited data conditions, providing a promising approach for real-world industrial bearing fault diagnosis.
Design and optimization of lightweight bending strain energy harvesters using irradiation cross-linked polypropylene ferroelectret
Authors: Holzmann H , Park Y J , Stoll G , Atzrodt H , Herold S 
Published: July 2023

Abstract
In this work, a concept for bending strain energy harvesting with lightweight ferroelectrets subject to metallic host structures is proposed. The energy harvester (EH) works with the ferroelectret irradiation cross-linked polypropylene (IXPP) and uses the piezoelectric δ
33-mode by transferring in-plane bending strain energy of a host structure to a compression of an IXPP stack. This is achieved with a simple and lightweight transmission made of structural steel. In this way, a high ratio of generated power per used EH mass can be achieved, being the main design goal of this paper. To demonstrate this, miniature EHs as unit cells for larger EH systems are investigated. The strain magnitude of the excitation in an aircraft wing of

4.5
⋅

10

−
5

m

m

−
1

at 1.5 Hz from previous work is partly taken into account for calculations. In an analytical modeling approach, the energy conversion abilities of the presented concept is compared to concepts using lead zirconate titanate ceramics to stress the usefulness in cases where strain energy is the prominent source of vibration energy. Further, an optimization algorithm is presented for a static and a dynamic case without a host structure and for a dynamic case with an aluminum host structure. The optimized power output and power output per total EH mass for the three cases is calculated to

1.52
μ

W

and

271
μ

W

k
g

−
1

, 0.7 mW and 80 mW kg−1 as well as

6.53
μ

W

(at 1 N excitation magnitude) and

10.8

m
W

k
g

−
1

(at 1 N excitation magnitude) respectively. Finally, experimental results for case three are presented to validate the model of the proposed and optimized EH topology up to 500 Hz. The results further show a good mechanical reproducibility of the measured transfer behavior and a fairly good reproducibility of the mechanical-electrical results due to deviations in material properties. A comparison of the model with the experimental results shows a good agreement. Therefore a linear ferroelectret model appears to be suitable to predict the system behavior in lower and higher frequency ranges as well as for high ferroelectret material strains. The optimized EH provides a comparably high ratio of power output per mass when added to a structure like an aircraft which is shown in a comparison to other research works. The performance in a real application can be further improved to 52 mW within a 1 m2 area using a clustering approach, discussed in the paper. Large deformations of lightweight structures like aircraft wings at low and high frequencies can thus be exploited to provide enough electrical power decentrally for low-power consumers.
Abnormally autofocusing vortex Swallowtail Gaussian vector beam with low spatial coherence
Authors: Shi Jingyi , Liang Zehong , Wu You , Wei Quanfeng , Shui Lingling , Deng Dongmei 
Published: July 2023

Abstract
The precondition for the application of light beams is the ability to devise light distribution with high precision. Controlling more dimensions for structured light fields is an effective method to improve the ability to devise light distribution. The Swallowtail beam, due to its rich regulatory parameters, provides the possibility to design a light field with a specific intensity distribution. Utilizing the Swallowtail beam as a foundation, we design its initial phase, polarization, and coherent structure, and propose a partially coherent azimuthally polarized circular vortex Swallowtail Gaussian beam (PCAPCVSGB) in our paper. This beam exhibits an abnormal self-focusing ability and forms an easily adjustable optical potential well at the focal plane, providing another effective tool for achieving optical manipulation. In addition, the PCAPCVSGB also shows an interesting vector property. It possesses a stable polarization singularity even with changes in coherence and topological charges, which exhibits a potential application value in optical communication.
Nondegenerate two-way edge channels of plasmons in networks
Authors: Sasaki Ken-ichi 
Published: July 2023

Abstract
An effective one-dimensional channel is formed at the periphery of a two-dimensional electron gas by electronic edge states. Robust edge states with suppressed dissipation arise from the Landau quantization in a strong magnetic field, and propagation through an edge channel formed by these states is one-way. In general, two-way edge channels rather than one-way ones have more advantages for applications and are the main topic of topological insulators. However, two-way edge channels of these are degenerate in their energies, which causes backscattering and dissipation. Here, we show that excited states in networks composed of capacitively coupled integer quantum Hall systems exhibit macroscopic two-way edge channels with different energies. Theoretical results are derived on the basis of two known effects; each system has plasmonic excitations known as edge magnetoplasmons, and the chirality of each system is diverted only locally by the capacitive interaction between nearest-neighbor systems. Because of the simplicity of the model, various extensions from regular networks to more complicated higher-dimensional networks are possible. The networks provide an ideal platform to test the functionality of plasmonic one-dimensional edge channels and suggest a dynamical model of fractional Quantum Hall systems.
Gaussian beam propagation in a Lorentz-violating vacuum in the presence of a semi-transparent mirror
Authors: Escobar C A , Martín-Ruiz A , Mondragón M , Jáuregui R 
Published: July 2023

Abstract
In this paper we study the propagation of structured optical scalar beams in a Lorentz-violating (LV) vacuum parametrized by a constant 4-vector u

μ
and in the presence of a semi-transparent mirror. The two bosonic degrees of freedom of the electromagnetic field can be described by a LV extension of the massless scalar field theory, whose LV part is characterized by the term (u · ∂ϕ)2. The mirror at a surface Σ is modelled by a delta-type potential in the Lagrange density for the LV scalar field, i.e. λ
δ(Σ)ϕ
2, where the parameter λ controls the degree of transparency of the mirror. Using Green’s function techniques, we investigate the propagation of a Gaussian beam in the presence of a mirror which is perpendicular to the propagation direction and for two particular choices of the background 4-vector: parallel and perpendicular to the propagation direction. To quantify the Lorentz-violating effects we introduce the fidelity as a measurement of the closeness of the propagated field distribution with respect to that in the conventional vacuum. In the absence of the mirror (λ = 0) the fidelity is found to be close to one, and hence LV effects are quite small. However in the presence of the mirror, there are regions where the fidelity drops to zero, thus implying that LV effects could be clearly differentiated from the propagation in vacuum. Within the paraxial approximation we determine analytically the LV effects upon the Rayleigh range, the radius of the beam, the Gouy phase and the radius of curvature of the wavefronts. We discuss possible scenarios where our results could apply, by using optically transparent multiferroic materials, which offer unprecedented opportunities to tailor structured beam propagation, as well as to simulate an LV vacuum.
PIC simulations of stable surface waves on a subcritical fast magnetosonic shock front
Authors: Dieckmann M E , Huete C , Cobos F , Bret A , Folini D , Eliasson B , Walder R 
Published: July 2023

Abstract
We study with particle-in-cell (PIC) simulations the stability of fast magnetosonic shocks. They expand across a collisionless plasma and an orthogonal magnetic field that is aligned with one of the directions resolved by the 2D simulations. The shock speed is 1.6 times the fast magnetosonic speed when it enters a layer with a reduced density of mobile ions, which decreases the shock speed by up to 15% in 1D simulations. In the 2D simulations, the density of mobile ions in the layer varies sinusoidally perpendicularly to the shock normal. We resolve one sine period. This variation only leads to small changes in the shock speed evidencing a restoring force that opposes a shock deformation. As the shock propagates through the layer, the ion density becomes increasingly spatially modulated along the shock front and the magnetic field bulges out where the mobile ion density is lowest. The perturbed shock eventually reaches a steady state. Once it leaves the layer, the perturbations of the ion density and magnetic field oscillate along its front at a frequency close to the lower-hybrid frequency; the shock is mediated by a standing wave composed of obliquely propagating lower-hybrid waves. We perform three 2D simulations with different box lengths along the shock front. The shock front oscillations are aperiodically damped in the smallest box with the fastest variation of the ion density, strongly damped in the intermediate one, and weakly damped in the largest box. The shock front oscillations perturb the magnetic field in a spatial interval that extends by several electron skin depths upstream and downstream of the shock front and could give rise to Whistler waves that propagate along the shock’s magnetic field overshoot. Similar waves were observed in hybrid and PIC simulations and by the MMS satellite mission.
Tuning of magnetic properties of Al-doped cobalt ferrite nanofiber prepared by electrospinning technique
Authors: Das Tupan , Noor Saima , Kumari Suman , Mallick Jyotirekha , Shukla Anant , Datta Subhadeep , Manglam Murli Kumar , Kar Manoranjan 
Published: July 2023

Abstract
The Al-doped cobalt ferrite (CoFe2-xAlxO4) nanofiber has been prepared by employing the electrospinning technique. All the nanofibers are characterized by the XRD technique. The Rietveld refinement of the XRD pattern reveals the spinel cubic structure with the Fd

3
¯

m space group. The TEM micrographs confirm the formation of nanofiber with a nearly uniform diameter of ∼137 ± 10 nm. The magnetic properties of all the nanofibers have been investigated by measuring the M-H hysteresis loops with the help of a Vibrating sample magnetometer (VSM). The M-H loops analysis demonstrates a reduction in the saturation magnetization, and coercivity from 106.88 emu g−1 to 40.01 emu g−1 and 0.897 kOe to 0.324 kOe, respectively, with the increase in Al concentration in the nanofibers. The ‘Law of Approach to Saturation’ technique has been employed to understand the magnetocrystalline anisotropy constant in the samples. The magnetocrystalline anisotropy constant (K
1) decreases with the increase in Al3+ substitution in place of Fe3+ in the spinel cobalt ferrite nanofibers. A squeezing effect on the M-H loop near M = 0 is observed and, it has been analyzed by a hysteresis loop width (∆H) versus magnetization (M) plot. The squeezing effect has been observed due to the exchange interaction phenomenon between the magnetic and non-magnetic atoms in the Al-doped cobalt ferrite nanofiber. The magnetic properties study demonstrates that Al-doped cobalt ferrite nanofiber exhibits soft magnetic nature.