bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase controllable FSR design and its application into a high-gain transmitarray antenna with a low radar cross-section
Authors: Zhang Zhiyun , Cao Xiangyu , Yang Huanhuan , Li Tong , Li Sijia , Ji Kefeng 
Published: October 2022

Abstract
In this study, a high-gain transmitarray antenna (TAA) is proposed to achieve a low radar cross-section (RCS) with polarization-insensitive characteristic. Initially, an anisotropic frequency selective rasorber (FSR) structure is constructed by a detailed analysis of the current distributions and parameter adjustments. Hence, manipulations of absorption and transmission are achieved, along with covering a transmission phase cycle by rotating the element at 90°. Then, employing a phase-controllable FSR and focal length optimization, a low-RCS and high-gain TAA is presented. For the radiation case, the proposed antenna has a pencil pattern with a peak gain of 21.8 dBi. The F/D ratio is low when a wide-beam feed is utilized. At scattering state, in-band and out-of-band 6 dB RCS reductions are realized ranging from 7.6 to 10.4 GHz and 11.6–12.4 GHz compared to the reference TA. Moreover, its bistatic RCS is reduced in approximately ±90° of angular space under normal incidence. The effectiveness of the proposed design is verified by experiments.
Two-dimensional axisymmetric radiation hydrodynamics model of moderate-intensity nanosecond laser-produced plasmas
Authors: Min Qi , Shen Ruizi , Su Maogen , Lu Haidong , He Siqi , Liu Xingbang , Li Yue , Tao Qianqian , Wu Yanhong , Sun Duixiong , Cao Shiquan , Dong Chenzhong 
Published: October 2022

Abstract
A two-dimensional axisymmetric radiation hydrodynamics model has been proposed to simulate nanosecond laser ablation of a solid target in ambient argon, air and helium at different pressures. The heat conduction equation used to simulate the conduction of laser deposition energy in the target and gas dynamic equations to describe the interaction between laser and vapor plasma and the evolution of plasma are coupled through the Knudsen layer relations at the target-vapor interface. A collisional-radiative model including 12 atomic processes is used to calculate the population of atomic energy levels and fractional ion abundance. The internal energy and pressure of the plasma are expressed by the equations of state based on a real gas approximation, which divides the internal energy into the ionization energy, thermal energy, and excitation energy of atoms and ions. The distributions of the temperature, pressure, density and velocity of the target and plasma are calculated by using this model, and the results are analyzed. Experimental results of multiple diagnostic tools including fast photography, shadowgraphy images, spatio-temporally resolved optical emission spectroscopy and laser interferometry, are used to benchmark the simulation results, and satisfactory consistencies are obtained. The model provides a numerical tool to interpret experimental data of a moderate-intensity nanosecond laser ablated solid target when the temperature of the target surface does not reach the critical value.
GaAs a model system to study the role of electron–phonon coupling on ionization stimulated damage recovery
Authors: Chakravorty Anusmita , Dufour Ch , Mishra Ambuj , Kanjilal D , Kabiraj Debdulal 
Published: October 2022

Abstract
The latent ion tracks observed in various materials after swift heavy ion (SHI) irradiation is often explained in the framework of thermal spike model (TSM). Dominantly, SHIs deposit most of their energy via intense ionization leading to a very high density of localized electronic excitations. The energy transfer from electrons to lattice, within a time of electronic cooling ∼100 fs, is governed by the ‘electron-phonon coupling’ parameter g. In this work, GaAs is used as a model system for studying ionization-stimulated damage recovery. Controlled damage is introduced using 300 KeV Ar ion irradiation, followed by successive irradiation using 100 MeV Ag ions at ∼80 K by varying the fluence (ions cm−2). The TSM is utilized to explain the observed recovery. Using the previously published value of

g
=
3.2
×

1012 W cm−3 K−1 for GaAs, the existing thermal spike code resulted in melting and quick quenching within ∼10 ps, suggesting the formation of SHI-induced tracks. However, experimental observations do not support the formation of tracks in pristine GaAs. Multiple simulation runs, for different g values, predict that for no melting in GaAs, g should be

⩽

1.4 × 1012 W cm−3 K−1. Finally, the 3D version of the TSM is used to simulate the temperature profiles after an impact of SHI irradiation on an amorphous nano-zone embedded in a crystalline GaAs matrix. Simulations predict that the thermal spike in this zone is confined, indicating melt-flow at the crystalline-amorphous interface that can promote recovery. This lattice recovery is further supported by both RBS/C and TEM results.
Delocalization and insulator to metal transition in PEDOT:PSS
Authors: Mohan Arya , Menon Reghu 
Published: October 2022

Abstract
Charge transport in poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS), with systematic increase in the percentages of dimethyl sulfoxide (DMSO) and ethylene glycol (EG), is investigated as a function of temperature and electric field down to 4.2 K. The conductivity in pristine PEDOT:PSS (1.4 S cm−1) increased to 1070 S cm−1 with 10% of DMSO, and to 565 S cm−1 with 6% of EG. The conductivity ratio (

σ
r

=

σ

300K

/

σ

4

.2K

) is substantially reduced to 2.5 in 10% DMSO sample. This gradual transition from insulator (variable range hopping) to disordered metal (T
1/2 fit), with an intermediate critical regime (power law), is observed by small variations in the volume fractions of these solvents. The temperature dependence of the ratio of hopping length to localization length (

R

/

L

c

)

is rather weak for samples (2D & 4EG) near the transition. As the delocalization increases in more conducting samples, larger electric field dependence of conductivity is observed at lower fields (0.1 V cm−1). The real part of impedance decreases at higher frequency and the peak in the imaginary part of impedance shifts to higher frequency as the sample conductivity increases.
Importance of magnetic shape anisotropy in determining magnetic and electronic properties of monolayer VSi2P4
Authors: Guo San-Dong , Tao Yu-Ling , Cheng Kai , Wang Bing , Ang Yee Sin 
Published: October 2022

Abstract
Two-dimensional (2D) ferromagnets have been a fascinating subject of research, and magnetic anisotropy (MA) is indispensable for stabilizing the 2D magnetic order. Here, we investigate magnetic anisotropy energy (MAE), magnetic and electronic properties of

V
S

i
2

P
4

by using the generalized gradient approximation plus U approach. For large U, the magnetic shape anisotropy (MSA) energy has a more pronounced contribution to the MAE, which can overcome the magnetocrystalline anisotropy (MCA) energy to evince an easy-plane. For fixed out-of-plane MA, monolayer

V
S

i
2

P
4

undergoes ferrovalley (FV), half-valley-metal (HVM), valley-polarized quantum anomalous Hall insulator (VQAHI), HVM and FV states with increasing U. However, for assumptive in-plane MA, there is no special quantum anomalous Hall (QAH) state and spontaneous valley polarization within considered U range. According to the MAE and electronic structure with fixed out-of-plane or in-plane MA, the intrinsic phase diagram shows common magnetic semiconductor, FV and VQAHI in monolayer

V
S

i
2

P
4

. At representative U = 3 eV widely used in references,

V
S

i
2

P
4

can be regarded as a 2D-XY magnet, not Ising-like 2D long-range order magnets predicted in previous works with only considering MCA energy. Our findings shed light on importance of MSA in determining magnetic and electronic properties of monolayer

V
S

i
2

P
4

.
Automated weak signal frequency estimation method based on Duffing oscillator and particle swarm optimization
Authors: Wang Yifan , Cheng Yuhua , Wang Li , Yan Yanjun , Zou Songting , Chen Kai 
Published: October 2022

Abstract
The frequency of a weak signal is used for fault diagnosis and target identification in various fields. By introducing particle swarm optimization (PSO) and spectral entropy (SE), an automated weak signal frequency estimation method based on the Duffing oscillator is proposed. The proposed method uses the differential structure to enhance the timing difference of the Duffing oscillator between the chaotic and large-scale periodic states, which is quantitatively distinguished by SE. Then, the frequency of the internal driving force is adaptively adjusted by the PSO to allow the SE to reach a minimum value where the driving frequency equals the weak signal frequency. A group of weak signals with different frequencies has been tested. The maximum relative frequency error is only 0.68%. Unlike other chaotic oscillator-based frequency estimation methods, the proposed method does not need to determine the phase state manually. A rough initial frequency search range is sufficient for automatic frequency measurement of the proposed method in this paper.
Novel scanning system with error separation for high-accuracy profile measurement
Authors: Guo Jingyang , Zhai Dede , Chen Shanyong , Liu Junfeng 
Published: October 2022

Abstract
This paper proposes a method based on a single-probe scanning system for measuring the profile error of an artifact. Our system employs the movement accuracy of a single sensor to achieve a virtual multi-sensor configuration that can function like a traditional multi-sensor. This novel virtual multi-probe scanning system and its corresponding method have the following benefits: (a) A high-accuracy profile can be reconstructed free of the guidance error of the scanning stage. The reconstructed profile has a very high lateral resolution, depending on the lateral resolution (µm level) of the probe. (b) Sensor drift can be restrained using our method, based on the principle of differential reconstruction. The high steep profile can also be measured with a scanning system moving along the measuring direction, thus extending the measuring range. We developed the measurement system and tested the effects of noise, drift, and other factors on the reconstruction results. Finally, some optical surfaces were measured, and comparisons were made between the results obtained from our method and those of a Zygo interferometer. There was high agreement between the two methods, with a deviation of approximately 0.1 μm.
Fast algorithm for time decay estimation with applications to electrostatic ion beam traps
Authors: Trigano T , Fradkin Z 
Published: October 2022

Abstract
The ability of peptide trapping in an electrostatic ion beam trap (EIBT) is used for the measurement of renin substrate lifetime dependence from the pressure. The time decay estimation is traditionally obtained by optimization of nonlinear curve-fitting in the least-squares sense. This paper presents a novel algorithm to address this problem, using a numerical differentiation method as the basis for lifetime estimation. Simulations results show that the proposed method provides results similar to those obtained with the classical approach, but is faster by about two orders of magnitude. An experimental result is detailed, which shows the adequacy of this algorithm for the real-life monitoring of decay measurements, not only for EIBT, but also for other processes such as luminescence where exponential decay is involved.
Error compensation for phase retrieval in deflectometry based on deep learning
Authors: Guan Jingtian , Li Ji , Yang Xiao , Chen Xiaobo , Xi Juntong 
Published: October 2022

Abstract
Fringe patterns are widely applied in optical metrology, and phase retrieval is an essential process for decoding surface information. In the field of phase measuring deflectometry (PMD), phase errors in the phase retrieval process have more significant effects for PMD is a slope-based technique and is more sensitive to low-frequency errors. The main factors affecting the quality of the captured fringe images include the gamma effect of the liquid crystal display screen, the random noise from the charge-coupled device camera, and the random noise amplified by the defocused fringe patterns. Conventional methods compensated the phase errors of these factors separately with different methods, which are inefficient in handling the errors from coupling factors effectively. In this paper, we propose a deep neural network to compensate for the phase errors resulting from the combination of the factors. Experimental results demonstrate that the proposed network can significantly suppress the errors in phase retrieval with non-ideal fringe images. The phase errors can be reduced in both simulated and authentic data for deflectometry, which verifies the robustness and effectiveness of the proposed method.
Highly sensitive triethylamine gas sensor by Pt-loaded p–n heterojunction Co3O4/WO3
Authors: Song Zhenlin , Zeng Jiyang , Zi Baoye , Chen Fengying , Zhang Yumin , Zhang Genlin , Zhu Zhongqi , Zhang Jin , Liu Qingju 
Published: October 2022

Abstract
Triethylamine (TEA) exists widely in production and life and is extremely volatile, which seriously endangers human health. It is required to develop high-performance TEA sensors to protect human health. We fabricated Pt-Co3O4/WO3 based on our previous work, and the performance was tested against volatile organic compounds. Compared with the previous work, its operating temperature was greatly reduced from 240 °C to 180 °C. The response value of Pt-Co3O4/WO3 was increased from 1101 to 1532 for 10 ppm TEA with good selectivity. These results show a significant step toward practical use of the Pt-Co3O4/WO3 sensor.
Measurement of wave propagation through a tube using dual transducers for elastography in arteries
Authors: Lee Hyoung-Ki , Capron Charles B , Liu Hsiao-Chuan , Roy Tuhin , Guddati Murthy N , Greenleaf James F , Urban Matthew W 
Published: October 2022

Abstract

Objective. Measuring waves induced with acoustic radiation force (ARF) in arteries has been studied over the last decade. To date, it remains a challenge to quantitatively assess the local arterial biomechanical properties. The cylindrical shape and waveguide behavior of waves propagating in the arterial wall pose complexities to determining the mechanical properties of the artery. Approach. In this paper, an artery-mimicking tube in water is examined utilizing three-dimensional measurements. The cross-section of the tube is measured while a transducer is translated over 41 different positions along the length of the tube. Motion in the radial direction is calculated using two components of motion which are measured from the two orthogonal views of the cross-section. This enables more accurate estimation of motion along the circumference of tube. Main results. The results provide more information to categorize the motion in tube wall into two types of responses: a transient response and a steady state response. The transient response is caused by ARF application and the waves travel along the length of the tube for a relatively short period of time. This corresponds to the axial and circumferential propagating waves. The two circumferential waves travel along the circumference of tube in CW (clockwise) and CCW (counter-clockwise) direction and result in a standing wave. By using a directional filter, the two waves were successfully separated, and their propagation was more clearly visualized. As a steady state response, a circumferential mode is generated showing a symmetric motion (i.e. the proximal and distal walls move in the opposite direction) following the transient response. Significance. This study provides a more comprehensive understanding of the waves produced in an artery-mimicking tube with ARF application, which will provide opportunities for improving measurement of arterial mechanical properties.
3D model-based super-resolution motion-corrected cardiac T1 mapping
Authors: Hufnagel Simone , Metzner Selma , Kerkering Kirsten Miriam , Aigner Christoph Stefan , Kofler Andreas , Schulz-Menger Jeanette , Schaeffter Tobias , Kolbitsch Christoph 
Published: October 2022

Abstract

Objective. To provide 3D high-resolution cardiac T1 maps using model-based super-resolution reconstruction (SRR). Approach. Due to signal-to-noise ratio limitations and the motion of the heart during imaging, often 2D T1 maps with only low through-plane resolution (i.e. slice thickness of 6–8 mm) can be obtained. Here, a model-based SRR approach is presented, which combines multiple stacks of 2D acquisitions with 6–8 mm slice thickness and generates 3D high-resolution T1 maps with a slice thickness of 1.5–2 mm. Every stack was acquired in a different breath hold (BH) and any misalignment between BH was corrected retrospectively. The novelty of the proposed approach is the BH correction and the application of model-based SRR on cardiac T1 Mapping. The proposed approach was evaluated in numerical simulations and phantom experiments and demonstrated in four healthy subjects. Main results. Alignment of BH states was essential for SRR even in healthy volunteers. In simulations, respiratory motion could be estimated with an RMS error of 0.18 ± 0.28 mm. SRR improved the visualization of small structures. High accuracy and precision (average standard deviation of 69.62 ms) of the T1 values was ensured by SRR while the detectability of small structures increased by 40%. Significance. The proposed SRR approach provided T1 maps with high in-plane and high through-plane resolution (1.3 × 1.3 × 1.5–2 mm3). The approach led to improvements in the visualization of small structures and precise T1 values.
Developing magnetorelaxometry imaging for human applications
Authors: Arsalani Soudabeh , Radon Patricia , Schier Peter , Jaufenthaler Aaron , Liebl Maik , Baumgarten Daniel , Wiekhorst Frank 
Published: October 2022

Abstract

Objective. Magnetic nanoparticles (MNPs) are a promising tool in biomedical applications such as cancer therapy and diagnosis, where localization and quantification of MNP distributions are often mandatory. This can be obtained by magnetorelaxometry imaging (MRXI). Approach. In this work, the capability of MRXI for quantitative imaging of MNP inside larger volumes such as a human head is investigated. We developed a human head phantom simulating a glioblastoma multiforme (GBM) tumor containing MNP for magnetic hyperthermia treatment. The sensitivity of our MRXI setup for detection of MNP concentrations in the range of 3–19 mg cm−3 was studied. Main result. The results show the high capability of MRXI to detect MNPs in a human head sized volume. Superficial sources with a concentration larger than 12 mg cm-3 could be reconstructed with a resulotion of about 1 cm-3. Significance. The reconstruction of the MNP distribution, mimicking a GBM tumor of 7 cm3 volume with clinically relevant iron concentration, demonstrates the in vivo feasibility of MRXI in humans.
Investigation of raman spectrum, structural, morphological, and optical features of Fe2O3 and Fe2O3/reduced graphene oxide hybrid nanocomposites
Authors: Abdel-Salam Ahmed I , Gomaa Islam , Khalid A , Soliman T S 
Published: October 2022

Abstract
The Hematite (Fe2O3) nanoparticles and Fe2O3-reduced graphene oxide (rGO) nanocomposite were successfully synthesized via co-precipitation method. The rGO was used as passivation layer to improve the optical properties of the Fe2O3. X-ray diffraction, transmission electron microscopy, Raman, and Fourier transform-infrared spectroscopy were used to investigate the modification in the Fe2O3 structure in the presence of rGO. UV-visible absorption spectra were investigated, and the optical bandgap was determined. Using different relations like Moss, Rivandra, Anani, and others, the refractive index was calculated depending on the obtained optical bandgap. The refractive index values were compared with the data calculated from Duffy relation and good accordance was found between them. The optical bandgap and electronegativity were found to decrease by the addition of rGO in Fe2O3 matrix, while the refractive index was found to increase. Consequently, the Fe2O3-rGO nanocomposites capacity to control optical properties makes it a perfect contender for a variety of applications.
Absorbing boundary condition as limiting case of imaginary potentials
Authors: Tumulka Roderich 
Published: October 2022

Abstract
Imaginary potentials such as V(x) = −iσ1Ω(x) (with σ > 0 a constant, Ω a subset of 3-space, and 1Ω its characteristic function) have been used in quantum mechanics as models of a detector. They represent the effect of a ‘soft’ detector that takes a while to notice a particle in the detector volume Ω. In order to model a ‘hard’ detector (i.e. one that registers a particle as soon as it enters Ω), one may think of taking the limit σ → ∞ of increasing detector strength σ. However, as pointed out by Allcock, in this limit the particle never enters Ω; its wave function gets reflected at the boundary ∂Ω of Ω in the same way as by a Dirichlet boundary condition on ∂Ω. This phenomenon, a cousin of the ‘quantum Zeno effect,’ might suggest that a hard detector is mathematically impossible. Nevertheless, a mathematical description of a hard detector has recently been put forward in the form of the ‘absorbing boundary rule’ involving an absorbing boundary condition on the detecting surface ∂Ω. We show here that in a suitable (non-obvious) limit, the imaginary potential V yields a non-trivial distribution of detection time and place in agreement with the absorbing boundary rule. That is, a hard detector can be obtained as a limit, but it is a different limit than Allcock considered.
Electron thermal internal transport barriers triggered by the effect of ion shielding
Authors: Ye Lei , Luo Zhengping , Xiao Xiaotao , Pan Chengkang , Wang Yuehang , Huang Yao , Zang Qing , Chen Fei , Jin Yifei , Wang Shouxin , Ding Bojiang , Xiao Bingjia , Wang Shaojie 
Published: October 2022

Abstract
The formation of electron thermal internal transport barriers (eITBs) is investigated by critical gradient threshold analysis for recent EAST experiments with dominant RF heating and low torque injection. The ratio of electron temperature to ion temperature, τ = T
e/T
i, is identified to be the key parameter that triggers eITB in the hot electron mode through electron turbulence suppression by the effect of ion shielding. The critical gradient of electron-temperature-gradient turbulence can be greatly increased with τ due to strong electron heating and weak electron–ion energy coupling. The formation and evolution of eITB is found to be determined by the critical temperature gradient of electron turbulence.
Selective Separation of Gases by Metal Organic Framework Materials (Mofs)
Authors: Hu Jiayi , Wang Yining , Wu Leyi 
Published: October 2022

Abstract
Gas separation is used to separate one or more gases from a mixture, which is crucial in the chemical industry. Compared with conventional porous materials, the distinctive physicochemical traits of MOFs play a dominant role in gas storage and separation. This review focuses on MOF materials in selective gas separation and current challenges. According to research, the usage of porous materials has achieved effective separation and greatly reduced energy consumption in nitrogen/oxygen (N2/O2) separation, acetylene/ethylene (C2H2/C2H4) separation, carbon capture and toxic gas separation. MOF’s unique structural features lead to the promising status for gas storage and separation. However, MOF materials still have some problems and challenges, e.g., the lack of practice for scientists to easily find a high-performance MOFs, high cost of MOF materials and shaping process. In the future, researchers around the world are looking to synthesize more and more artificial MOFs. Overall, these results offer a guideline for improvement of MOF materials.