bluuebunny/crossref_metadata_2025_split huggingface dataset:
Existence of density inhomogeneity of liquid Te associated with liquid–liquid phase transition
Authors: Kajihara Yukio , Inui Masanori , Matsuda Kazuhiro , Ohara Koji 
Published: May 2024

Abstract
We performed small-angle x-ray scattering measurements of liquid Te using a synchrotron radiation facility and observed maximum scattering intensity near 620 K in the supercooled region (melting temperature 723 K). This indicates that density inhomogeneity exists in liquid Te, and the fact that this temperature coincides with the temperature at which the specific heat, sound velocity, and thermal expansion coefficient reach their maxima means that this density inhomogeneity is the cause of these thermodynamic anomalies. The thermodynamic anomalies in liquid Te had already been shown in the 1980s to be comprehensively explained by the inhomogeneity associated with the continuous liquid–liquid phase transition (LLT), but direct experimental evidence for the existence of the inhomogeneity had not been obtained. The present results, together with those already obtained for mixture systems (Te–Se, Te–Ge), indicate the existence of inhomogeneity associated with LLT in liquid Te systems, and strongly support the model. Recently, similar maximum scattering intensity has also been observed in supercooled liquid water, which exhibits thermodynamic anomalies similar to those of Te, indicating the universality of the inhomogeneous model or LLT scenario to explain the thermodynamics of such ‘anomalous liquids’. Further development of the LLT scenario is expected in near future.
Study of conduction mechanisms of InSeSb nano-chalcogenide alloys
Authors: Thakur Diksha , Rangra Vir Singh 
Published: May 2024

Abstract
The electrical conduction mechanisms for bulk samples of In0.1Se0.9−x
Sb
x
(x = 0, 0.04, 0.08 and 0.12) nano-chalcogenide system, synthesized by the melt-quenching technique are investigated through current–voltage (I–V) characteristics. For the detailed study of conduction mechanism pellets of bulk samples are prepared. A thorough examination of electrical conductivity is done in the temperature range of 295–318 K and 0–50 V voltage range. From I–V measurements it is observed that samples are showing ohmic nature at lower field and non-ohmic nature at relatively higher field values. The temperature dependence of DC conductivity is analyzed using the Arrhenius relationship which is found to increase with Sb content. The value of activation energy and pre-exponential factor are calculated, which revealed that the conduction is due to the hopping of charge carriers among the localized states. Different parameters of Mott’s variable range hopping such as degree of disorder T
0, density of localized states N(E
F), hopping distance (R
hop), and hopping energy (W) are calculated. For the high field conduction process Poole–Frenkel, and Schottky processes are studied.
Modulating electronic structure by interlayer spacing and twist on bilayer bismuthene
Authors: Zhang Hongfei , Cheng Shuwei , Chen Yuanping , Chu Shibing 
Published: May 2024

Abstract
Modulation of the electronic structure has played a crucial role in advancing the field of two-dimensional materials, but there are still many unexplored directions, such as the twist angle for a novel degree of freedom, for modulating the properties of heterostructures. We observed a distinct pattern in the energy bands of bilayer bismuthene, demonstrating that modulating the twist angle and interlayer spacing significantly influences interlayer interactions. Our study of various interlayer spacings and twist angles revealed a close relationship between bandgap size and interlayer spacing, while the twist angle notably affects the shape of the energy bands. Furthermore, we observed a synergistic effect between these two factors. As the twist angle decreases, the energy bands become flat, and flat bands can be generated without requiring a specific angle on bilayer bismuthene. Our results suggest a promising way to tailor the energy band structure of bilayer 2D materials by varying the interlayer spacing and twist angle.
Multiparameter measurement depending on the cavity-length differentiation characteristics of a microfiber Fabry–Perot interferometer
Authors: Liu Fangfang , Ran Xin , Liu Xinyang , Jiang Ying , Yan Pen , Li Shizhao , Li Hongli , Zhao Huining , Xia Haojie 
Published: May 2024

Abstract
To solve the cross-sensitivity problem affecting optical fiber sensors and realize multiparameter measurement, a microfiber Fabry–Perot interferometer (MFPI) is proposed and experimentally demonstrated. Simultaneous measurement of two distinct physical parameter (temperature and strain) is realized by monitoring wavelength and reflectivity of MFPI. In the temperature field range of 22 °C–36 °C, the maximum temperature sensitivity can reach 12 pm °C−1. The maximum strain sensitivity is up to 0.8 pm/μϵ in the strain range of 0–800 μϵ. In the simultaneous measurement experiments, the relative errors of temperature and strain were 4.0% and 0.8%, respectively. Furthermore, the sensing element used in this method was just a single fiber grating sensor without any coating layer, which demonstrated the significant advantage of the proposed method in reducing the complexity and cost of multiparameter measurement.
Radial vibration measurement of rotating shaft using constant density fringe pattern and line scan camera
Authors: Huang Yuexin , Liu Dongming , Zhong Jianfeng , Zhong Shuncong 
Published: May 2024

Abstract
The radial vibration signals of the rotor can provide abundant information about the health condition of the machine. In this paper, a simple vision-based measurement system is proposed to simultaneously measure two-dimensional displacements in radial directions for the rotating shaft, where the system consists of a constant density fringe pattern (CDFP), a line scan camera (LSC), and a lens. The CDFP should be installed around the surface of the rotating shaft to make the density of the fringe constant along the shaft axis, while the shaft axis is vertical to the optical axis of the LSC but not parallel to the line-array sensor of the LSC. Therefore, the density of the fringe imaged on the LSC is not constant because of the modulation of the circular surface of the shaft, and the distribution of the fringe density on the LSC is a U-shaped curve. Thus, the shaft centreline orbit can be tracked by the lowest point of the density distribution curve (DDC) of the fringe. Then, an efficient and accurate parameterized instantaneous frequency estimation method is employed to estimate the DDC of the fringe, because the variable density fringe can be regarded as an amplitude-modulated and frequency-modulated nonstationary signal whose instantaneous frequency function is equivalent to the DDC. Experimental results verify the feasibility and effectiveness of the proposed method by comparing it to the eddy current sensors.
Fluorescence lifetime of plant leaves with sub-nanosecond resolution
Authors: Illés L , Sági-Kazár M , Steinbach F , Hembrom R , Mihailova G , Georgieva K , Solymosi K , Barócsi A , Solti Á , Lenk S 
Published: May 2024

Abstract
The study aimed to develop a measurement apparatus for in vivo chlorophyll-a (Chl-a) fluorescence decay measurements of plants by means of time correlated single photon counting. In this approach, sub-nanosecond laser pulses with a repetition rate of 10 MHz are applied to excite the sample, followed by the analysis of arrival times of the emitted fluorescence photons. Photon statistics are generated by iteratively fitting the sum of two exponential functions. The tool was tested on both plastid and in vivo leaf samples of Savoy cabbage (Brassica oleracea var. sabauda) with 3–4 subsequent leaves giving a complete sample coverage starting from the outermost. The Chl-a fluorescence lifetime exhibited a gradual increase in both the isolated plastid suspensions and the in vivo leaf samples towards the innermost leaf layers explained by an increase of natural absence of light (etiolation syndrome). Furthermore, cadmium stress and iron deficiency were investigated on treated sugar beet (Beta vulgaris) samples in vivo using TCSPS measurements. The reduced fluorescence quenching resulted in an increased fluorescence lifetime. Finally, a long-term (10 week) testing of the setup was carried out on Chl-retaining resurrection Haberlea rhodopensis plants protecting themselves by an elevated non-photochemical quenching yielding a decrease of fluorescence lifetime during their desiccation.
A reference-point-method-based online proton treatment plan re-optimization strategy and a novel solution to planning constraint infeasibility problem
Authors: Qiu Zihang , Depauw Nicolas , Gorissen Bram L , Madden Thomas , Ajdari Ali , den Hertog Dick , Bortfeld Thomas 
Published: May 2024

Abstract

Objective. Propose a highly automated treatment plan re-optimization strategy suitable for online adaptive proton therapy. The strategy includes a rapid re-optimization method that generates quality replans and a novel solution that efficiently addresses the planning constraint infeasibility issue that can significantly prolong the re-optimization process. Approach. We propose a systematic reference point method (RPM) model that minimizes the l-infinity norm from the initial treatment plan in the daily objective space for online re-optimization. This model minimizes the largest objective value deviation among the objectives of the daily replan from their reference values, leading to a daily replan similar to the initial plan. Whether a set of planning constraints is feasible with respect to the daily anatomy cannot be known before solving the corresponding optimization problem. The conventional trial-and-error-based relaxation process can cost a significant amount of time. To that end, we propose an optimization problem that first estimates the magnitude of daily violation of each planning constraint. Guided by the violation magnitude and clinical importance of the constraints, the constraints are then iteratively converted into objectives based on their priority until the infeasibility issue is solved. Main results. The proposed RPM-based strategy generated replans similar to the offline manual replans within the online time requirement for six head and neck and four breast patients. The average target D
95 and relevant organ at risk sparing parameter differences between the RPM replans and clinical offline replans were −0.23, −1.62 Gy for head and neck cases and 0.29, −0.39 Gy for breast cases. The proposed constraint relaxation solution made the RPM problem feasible after one round of relaxation for all four patients who encountered the infeasibility issue. Significance. We proposed a novel RPM-based re-optimization strategy and demonstrated its effectiveness on complex cases, regardless of whether constraint infeasibility is encountered.
Directional TV algorithm for image reconstruction from sparse-view projections in EPR imaging
Authors: Qiao Zhiwei , Liu Peng , Fang Chenyun , Redler Gage , Epel Boris , Halpern Howard 
Published: May 2024

Abstract

Objective. Electron paramagnetic resonance (EPR) imaging is an advanced in vivo oxygen imaging modality. The main drawback of EPR imaging is the long scanning time. Sparse-view projections collection is an effective fast scanning pattern. However, the commonly-used filtered back projection (FBP) algorithm is not competent to accurately reconstruct images from sparse-view projections because of the severe streak artifacts. The aim of this work is to develop an advanced algorithm for sparse reconstruction of 3D EPR imaging. Methods. The optimization based algorithms including the total variation (TV) algorithm have proven to be effective in sparse reconstruction in EPR imaging. To further improve the reconstruction accuracy, we propose the directional TV (DTV) model and derive its Chambolle–Pock solving algorithm. Results. After the algorithm correctness validation on simulation data, we explore the sparse reconstruction capability of the DTV algorithm via a simulated six-sphere phantom and two real bottle phantoms filled with OX063 trityl solution and scanned by an EPR imager with a magnetic field strength of 250 G. Conclusion. Both the simulated and real data experiments show that the DTV algorithm is superior to the existing FBP and TV-type algorithms and a deep learning based method according to visual inspection and quantitative evaluations in sparse reconstruction of EPR imaging. Significance. These insights gained in this work may be used in the development of fast EPR imaging workflow of practical significance.
Comparison of admittance and cardiac magnetic resonance generated pressure-volume loops in a porcine model
Authors: Andersen Stine , Laursen Pernille Holmberg , Wood Gregory John , Lyhne Mads Dam , Madsen Tobias Lynge , Hansen Esben Søvsø Szocska , Johansen Peter , Kim Won Yong , Andersen Mads Jønsson 
Published: May 2024

Abstract

Objective. Pressure-volume loop analysis, traditionally performed by invasive pressure and volume measurements, is the optimal method for assessing ventricular function, while cardiac magnetic resonance (CMR) imaging is the gold standard for ventricular volume estimation. The aim of this study was to investigate the agreement between the assessment of end-systolic elastance (Ees) assessed with combined CMR and simultaneous pressure catheter measurements compared with admittance catheters in a porcine model. Approach. Seven healthy pigs underwent admittance-based pressure-volume loop evaluation followed by a second assessment with CMR during simultaneous pressure measurements. Main results. Admittance overestimated end-diastolic volume for both the left ventricle (LV) and the right ventricle (RV) compared with CMR. Further, there was an underestimation of RV end-systolic volume with admittance. For the RV, however, Ees was systematically higher when assessed with CMR plus simultaneous pressure measurements compared with admittance whereas there was no systematic difference in Ees but large differences between admittance and CMR-based methods for the LV. Significance. LV and RV Ees can be obtained from both admittance and CMR based techniques. There were discrepancies in volume estimates between admittance and CMR based methods, especially for the RV. RV Ees was higher when estimated by CMR with simultaneous pressure measurements compared with admittance.
A novel double-gate trench SOI LDMOS with double-dielectric material by TCAD simulation study
Authors: Guo Jinjun , Dai Hongli , Wang Luoxin , Xue Yuming , Lyu Haitao , Niu Wenze 
Published: May 2024

Abstract
In this paper, a novel double-gate trench silicon-on-insulator lateral double-diffused metal oxide semiconductor field-effect transistor (LDMOS) with double-dielectric material (DGDK-LDMOS) is proposed. DGDK-LDMOS has two dielectric materials: a reverse-L-shaped high-k (HK) thin film and an low-k (LK) buried oxide layer. The HK thin film optimizes the electric field distribution on the drift region surface, attracting electric flux, and the excellent withstand voltage of the LK buried oxide layer can significantly improve the breakdown voltage (BV) and reduce specific on-resistance (R
on,sp) of the device. The modulation mechanism of LDMOS by HK thin film and LK buried oxide layer is analyzed. The results show that compared with conventional LDMOS, when the permittivity of HK thin film is 25 and the permittivity of LK buried oxide is 3, the BV of DGDK-LDMOS is increased by 89.6%, the R
on,sp is decreased by 26.4%, and the figure of merit (FOM, FOM = BV2/R
on,sp) is increased by 397.2% from 3.6 MW cm−2 to 17.9 MW cm−2. Meanwhile, the output characteristics, transfer characteristics, lattice temperature, AC characteristics and switching characteristics of DGDK-LDMOS are also discussed and compared.
Self-centering of steel braced frames equipped with Fe-SMA TADAS dampers
Authors: Torabizadeh Amirreza , Foyouzat Alireza , Asghari Abazar , Mohammadi Soheil 
Published: May 2024

Abstract
This study proposes a novel triangular added damping and stiffness (TADAS) damper that uses the shape memory effect of iron-based shape memory alloy (Fe-SMA) to provide a self-centering system to recover the initial shape of a structure after significant inelastic deformation induced by nonlinear response of fused elements, without the need for difficult and expensive replacement procedures of conventional TADAS systems. Unlike most studies which consider simplified uniaxial behavior of Fe-SMAs, the present non-linear finite element simulations cover the full 3D material non-linearity of Fe-SMA component based on the SMA constitutive law to capture both flexural and shear behavior in various coupled thermomechanical loadings, including the mechanical loading/unloading, the heating, and the final cooling (as the recovering process). Simulations performed on a one-bay steel frame for different drift ratios reveal that although the dissipation energy of the new device is at most 10% less than the ordinary one, it enjoys the self-centering property to recover the initial shape of the frame before loading, showing that the proposed damper is an effective alternative to ordinary TADAS yielding dampers to achieve the self-centering characteristics.
Spin-charge-lattice couplings and Co doping effect in Ba(Fe

1
−
x

Co

x

)2As2: an ab initio molecular dynamics study
Authors: He Hui-Hui , Yang Huan-Cheng , Lu Zhong-Yi , Liu Kai 
Published: May 2024

Abstract
As one of the typical iron-based superconductors, Ba(Fe

1
−
x

Co
x
)2As2 exhibits a dome-like evolution of superconducting transition temperature T
c with the Co doping (x), which provides an ideal platform to explore the mechanism of unconventional superconductivity. Through ab initio molecular dynamics (AIMD) studies, we find that the spin, charge, and lattice degrees of freedom in Ba(Fe

1
−
x

Co
x
)2As2 are intimately coupled with a characteristic frequency around 5.5 THz, which originates from the

A

1
g

phonon mode of the As atoms. Compared with the undoped BaFe2As2, the spin dynamics in Ba(Fe

1
−
x

Co
x
)2As2 (x = 0.0625, 0.1250, 0.1875) shows enhanced spatial inhomogeneities, though the features of the charge dynamics are rarely modified. Along with the increasing Co doping, the spatial inhomogeneities of Fe spin dynamics display nonmonotonic changes, meanwhile the lattice vibrational spectra first show peak broadening and then restore the main peak around 5.5 THz, being both consistent with the nonmonotonic behavior of superconducting T
c. Our study provides a molecular dynamics approach to investigate the couplings of spin, charge, and lattice in doped BaFe2As2, which could also be applied to explore the dome-like evolution of superconductivity in other Fe-based superconductors.
High critical current properties of multi-filamentary MgB2 superconducting wires fabricated using an internal Mg diffusion method
Authors: Chen Wenwu , Nong Xiaoyao , Wang Zhihan , Li Jianwei , Yang Luan , Lin He , Pan Xifeng 
Published: May 2024

Abstract
Although both the mass density and grain connectivity of MgB2 superconducting layers can be greatly improved via an internal Mg diffusion (IMD) process, the poor structural uniformity and low MgB2 filling factor of IMD wires limit further enhancement of their superconducting performance. Herein, we prepared 19-filament and 37-filament IMD-MgB2 superconducting wires using a combination of optimization of the component structure and the introduction of an intermediate annealing process. Microstructure analysis suggests that good structural uniformity and high layer density have been achieved in the multi-filamentary MgB2 wires, and the MgB2 filling factor reaches 9.3%–11.0%. The magnetic superconducting transition of MgB2 wires is relatively sharp, and the onset T
c is around 37 K. Remarkably, there is no magnetic flux jump for 37-filament wires in the low-field region at 5 K. At 4.2 K and 4 T, the transport layer J
c values of 19-filament and 37-filament MgB2 wires are as high as 1.5 × 105 A cm−2 and 2.2 × 105 A cm−2, respectively, with, accordingly, engineering J
e values of 1.7 × 104 A cm−2 and 2.0 × 104 A cm−2. These results indicate that the performance of multi-filamentary IMD-MgB2 wires can compete with traditional powder-in-tube-MgB2 wires applied in industry.
The average transmitted wave in random particulate materials
Authors: Karnezis Aristeidis , Piva Paulo S , Gower Art L 
Published: May 2024

Abstract
Microwave remote sensing is significantly altered when passing through clouds or dense ice. This phenomenon is not unique to microwaves; for instance, ultrasound is also disrupted when traversing through heterogeneous tissues. Understanding the average transmission in particle-filled environments is central to improve data extraction or even to create materials that can selectively block or absorb certain wave frequencies. Most methods that calculate the average transmitted field assume that it satisfies a wave equation with a complex effective wavenumber. However, recent theoretical work has predicted more than one effective wave propagating even in a material which is statistically isotropic and for scalar waves. In this work we provide the first clear evidence of these predicted multiple effective waves by using high-fidelity Monte-Carlo simulations that do not make any statistical assumptions. To achieve this, it was necessary to fill in a missing link in the theory for particulate materials: we prove that the incident wave does not propagate within the material, which is usually taken as an assumption called the Ewald–Oseen extinction theorem. By proving this we conclude that the extinction length—the distance it takes for the incident wave to be extinct—is equal to the correlation length between the particles.
Strong-coupling mean-field and classical percolation approach to produce the phase diagram of disordered Bose–Hubbard model at fixed n = 1 filling
Authors: Gupta Manjari 
Published: May 2024

Abstract
We perform strong-coupling mean-field along with classical percolation analysis to produce the phase diagram of disordered Bose–Hubbard model with chemical potential disorder in two dimensional square lattice. The phase diagram in the disorder strength (Δ) and the on-site repulsion (U), for two and three dimensional system at fixed n = 1 filling show interesting re-entrant superfluid phase sandwiched between Bose-glass phases, as observed by the previous QMC results. We produce the phase diagram exhibiting the re-entrant phenomenon as well as phenomenologically demonstrate the robustness of the re-entrant phenomena within this method. We also discuss the importance of the method and applicability in further analysis of the same phase diagram.