bluuebunny/crossref_metadata_2025 huggingface dataset:
Accelerating the magnetic island by the modulated resonant magnetic perturbation for the disruption avoidance on J-TEXT
Authors: Li Da , Wang Nengchao , Ding Yonghua , Yu Qingquan , Li Mao , Hu Qiming , He Ying , Mao Feiyue , Shen Chengshuo , Jia Ruo , Huang Zhuo , Zhou Song , Li Shuhao , Bala Abba Alhaji , Chen Zhipeng , Chen Zhongyong , Yang Zhoujun , Rao Bo , Jiang Zhonghe , Yi Lin , Yu Kexun , Pan Yuan
Published: August 2022

The acceleration of the magnetic island rotation by the modulated resonant magnetic perturbation (MRMP) has been studied in J-TEXT tokamak experiments. After applying the MRMP, the phase difference between the tearing mode (TM) and MRMP, Δξ, oscillated near the effective phase difference, Δξ
eff, which was defined as the time averaged value of Δξ. When the Δξ
eff was closed to the—π/2, the MRMP only contributed an accelerating torque on the TM. As the result, the TM rotation frequency was increased by a few kilohertz for the optimized relative phase by small RMPs of the order of 10−5 of the toroidal field and the locked mode induced disruption was avoided. It is found that the TM rotation could be increased to a higher frequency by applying a stronger MRMP. There is a negative sinusoidal relationship between TM frequency and Δξ
eff.
The crossed-beam energy transfer model without empirical factor for multi-beam irradiation of a spherical laser target
Authors: Demchenko N N
Published: August 2022

Stimulated Brillouin scattering of laser radiation in an expanding plasma during compression of a spherical target can significantly reduce the fraction of absorbed energy. A model of CBET (crossed-beam energy transfer) stimulated scattering under multi-beam irradiation of a spherical target has been developed. The model does not contain empirical factor, unlike the model known in the literature. This makes it possible to use it in calculations for the conditions of planned experiments. Calculations of the fraction ΔCB of energy released from the plasma due to CBET scattering for experimental conditions at the OMEGA installation have been carried out. It is shown that this fraction depends on the factor fe
of the electron heat flux limitation. With fe
values in the range 0.04–0.06, the calculated values of ΔCB (0.12–0.084) are close to the value 0.1 obtained in the experiment and in numerical simulation at fe
= 0.06.
The principle of minimal power
Authors: Kolobov Vladimir I , Golubovskii Yuri B
Published: August 2022

This article is devoted to the memory of Yuri P Raizer, who passed away in 2021. He left a noticeable trace in gas discharge physics. The principle of minimal power (the state that requires minimal power is most probable) is thoroughly used in his books. Although the fundamental laws of physics do not imply this ad hoc principle, a detailed analysis of underlying phenomena can often reveal why nature prefers this path. Raizer illustrated this principle for plasma stratification, formation of electrode spots, discharge constriction, the shape of an arc channel, etc. We argue that the nonlinearity of equations describing gas discharges can often justify the realization of a plasma state maintained at minimal electric power. This nonlinearity appears because small groups of energetic electrons often control the ionization processes. The number of these electrons depends strongly on the ratio of the electric field to gas density, E/N. Under certain conditions, the ionization rate can also depend nonlinearly on electron density due to stepwise ionization and Coulomb collisions. We use the principle of minimal power to illustrate some of Raizer’s contributions to gas discharge physics from a single point of view. We demonstrate that nonlinearity of ionization processes in gas discharges can substantiate this principle for plasma stratification. However, striations of s, p, and r types in neon could exist with minimal or no ionization enhancement. This reminds us of Raizer’s warning that applying the minimal power principle could lead to erroneous predictions, and a proper theory is required in each case to justify its use. ‘The phenomenon of striations satisfies the principle of minimal power’ – Yuri Raizer
Design of film supported single mesa Schottky diodes for above 1THz application with submicron T-junction
Authors: Liu Xiaoyu , Zhang Yong , Zhou Jingtao , Wei Haomiao , Wu Nan , Jin Zhi , Yan Bo , Xu Ruimin
Published: August 2022

A high-performance terahertz Schottky barrier diode (SBD) with a film-supported single mesa structure featuring a low structural parasitic with extremely low dielectric loss is reported in this brief. The fabricated substrate-free SBD is supported with a 2–3 µm polymer film using a low parasitic coupling capacitor of about 0.12 fF. It significantly reduces the electromagnetic coupling effect between the anode and cathode pads by 90% compared with the traditional structure of the same size. To reduce the Schottky junction capacitance at the anode, a submicron T-junction process is used with a low junction capacitance of 0.15 fF. The cutoff frequency calculated by the total capacitance of the diode is up to 4 THz. The substrate-free terahertz monolithic integration circuit based on this film-supported single mesa SBD has better performance in reducing the circuit dielectric loss, exhibiting a remarkable potential for high-frequency applications.
Understanding of carriers’ kinetic energy in steep-slope P+N+P+N+ feedback field effect transistor
Authors: Sung Juho , Shin Changhwan
Published: August 2022

A feedback field-effect transistor takes advantage of the charges accumulated in its potential well and the restriction of carrier flow by its internal potential barrier to achieve superior electrical properties such as a subthreshold swing, threshold voltage, transconductance, and on/off current ratio. However, the device must deal with the modulation of non-uniformity under forward/reverse bias and with completely losing carrier flow control during reverse bias below a certain channel length. In this work, we address these significant issues by focusing on the width of the source/drain and demonstrate the operation of positive feedback in n-type metal oxide semiconductor field-effect transistor (nMOSFET) using only one additional step, resulting in a superior subthreshold swing (∼3 mV/decade at 300 K), a low threshold voltage (∼0.26 V), hysteresis window (0.018 V), and clear saturation region.
Evaluation of vibrational properties and local structure change during phase transition in Ge2Sb2Te5 and In3SbTe2 phase change materials
Authors: Pathak Anushmita , Tanwar Manushree , Kumar Rajesh , Pandey Shivendra Kumar
Published: August 2022

Temperature-dependent local structural details of In3SbTe2 (IST) and Ge2Sb2Te5 (GST) phase change materials are explored with the aid of Raman scattering and x-ray photoelectron spectroscopy (XPS) techniques. Significant temperature-induced changes occur in the local structure of the phase change material, facilitating the amorphous to crystalline phase transformation. These two phases exhibit a large resistivity contrast, which is utilized to store data in the phase change memory application. The Raman spectra recorded for IST material suggest that the as-deposited sample (amorphous phase) first crystallized around 300

∘

C

annealing temperature with two binary phases InTe and InSb formations. InTe and InSb phases were obtained at ∼85.5 cm−1 and ∼180 cm−1 Raman shift, respectively, having vibration modes associated with B1g symmetry and transversal optical phonons with Г15 symmetry. Further annealing at a higher temperature of 400

∘

C

, a ternary IST phase is obtained at ∼163 cm−1 Raman shift indicating the transformation to a fully crystalline state. On the other hand, the amorphous GST material forms a metastable face-centred cubic phase and stable hexagonal (HEX) phase upon crystallization. The Raman findings demonstrate the changes in vibration modes of Ge–Te and Sb–Te bonds during phase switching without any phase separation. Crystalline GST (HEX phase) comprises rising peaks of GeTe4 and GeTe4−n
Ge
n
(n = 1, 2) corner-sharing tetrahedra with A1 mode at ∼104.5 cm−1 and ∼137 cm−1 Raman shift, respectively, and a declining Sb2Te3 peak at ∼175 cm−1, having A1g (2) vibration mode. Furthermore, the XPS analysis displays the changes in the bonding mechanism of the elements present in the phase change material during the amorphous to crystalline phase transition, firmly supporting the Raman observations.
GaN MSM structure UV photodetector detector based on nonplanar Si substrate and its performance optimization
Authors: Jiang Hang-Hui , Zhang Yan , Li Xue , Luo Yuan-Hang , Wen Chao , Xing Ya-kun , Xiao Meng-Zhen , Li Xin-Jian
Published: August 2022

Silicon (Si) based gallium nitride (GaN) possesses great development potential in fabricating integrated photodetectors. Nevertheless, the large lattice and thermal mismatch between Si and GaN usually brings about high-density dislocations and other line defects, which as a whole will seriously affect the responsiveness, working stability and service life of Si-based GaN (GaN/Si) devices. In this paper, we report that a GaN/Si ultraviolet photodetector (UV PD) with a metal-semiconductor-metal structure was prepared, using silicon nanoporous pillar array (Si-NPA) as nonplanar substrates. It will be shown that high-quality GaN/Si can be prepared and further improved by subsequent annealing treatment, by means of a three-dimensional stress release process brought about by using patterned Si substrates. Under a bias voltage of 1 V, the responsivity, specific detectivity, external quantum efficiency and rise/decay time of the detector were 71.4 mA·W−1, 7.1 × 108 Jones, 24.3% and 0.2/7.6 s, respectively. The results demonstrate that growing GaN on patterned Si substrates might be an effect route for constructing high-performance GaN/Si UV PDs.
Design, analysis and experiments of a stick-slip piezoelectric actuator working under the self-deformation mode
Authors: Yang Zhixin , Zhou Xiaoqin , Huang Hu
Published: August 2022

In this paper, the self-deformation mode of the stick-slip principle was proposed, and accordingly a piezoelectric actuator based on the self-deformation mode was designed, which could achieve stable bidirectional outputs with long stroke. To increase the stepping displacement of the output end and reduce the structural stress, an arc-shape flexible hinge with variable section was employed as the output part of the flexible hinge mechanism. The self-deformation motion was obtained by the deformation of the driving mechanism caused by the reaction force of the mover in the driving process. The stepping and self-locking characteristics of the actuator under various initial gaps were tested, and the evolution of stepping characteristics with the driving voltage, frequency and external load was analyzed. The experimental results showed that by the self-deformation mode, the long stroke with good linearity could be easily achieved for both the forward and reverse motions, and the maximum self-locking force reached 5 N. Furthermore, the maximum driving speed reached 2754 μm s−1 under the driving voltage of 120 V.
Effect of Be and P doping on the electron density, electrical and optoelectronic conduct of half-Heusler LiMgN within ab initio scheme
Authors: Ziat Younes , Zarhri Zakaryaa , Belkhanchi Hamza , Ifguis Ousama , Cano Andrés Domínguez , Lazrak Charaf
Published: August 2022

The effect of (Be- and P-) dopant has been investigated on the electronic structure and optoelectronic properties of LiMgN alloy, where the (Be and P) amount is 6.25%. The LiMgN alloy has an
XYZ
form which is crystallized in the

F

4

¯

3
m

(N° 216) space group. The ‘X
and
Y
’ are being substituted by Be and
Z
is substituted by P. The present investigation is carried out within the Wien2K package inside the TB-mBJ approximation. The present findings show that the Burstein–Moss (BM) shift is observed when Be is being in the Li position, and the Fermi level lies inside the CB. The ‘apparent band gap’ of Be doped LiMgN semiconductor is increased as the absorption edge is pushed to higher energies as a result of some states close to the CB being populated. This conduct is significant, as it gives a chance to get different optical characteristics for the same material and the ‘apparent band gap’ is equal to the actual band gap plus Burstein–Moss (BM) shift. The transmittance T(%) of Be element in the
Y
site is 76%. For the P doped LiMgN, the transmittance is 73%.
Third order nonlinearity and optical power limiting studies of PS/ZnO nanocomposite foils for photonic applications
Authors: Barala Monika , Maidur Shivaraj R , Mohan Devendra , Sanghi Sujata
Published: August 2022

The present work focuses on the preparation of Polystyrene (PS) and PS/ZnO nanocomposite foils by solution casting method and study their structural and nonlinear optical (NLO) characterizations. The Zinc Oxide (ZnO) nanoparticles were synthesized by Sol-gel method. Structural analysis of the prepared nanocomposite foils was carried out by x-ray diffraction (XRD) with an estimated average crystallite size of 27.33 nm. UV–vis-NIR spectra reveal that the nanocomposite foils are transparent in the visible region. FESEM micrographs show the surface morphology of the prepared nanocomposite foils. Energy Dispersive x-ray Spectroscopy (EDX) of the prepared foils confirmed the compositional and spatial distribution of the elements. The NLO properties such as nonlinear absorption coefficient (β), nonlinear index of refraction (n2), and third-order nonlinear susceptibilityχ3were investigated by Z-scan technique at a wavelength of 532 nm and 200 mW with field intensityI0=5.43KWcm−2.The values ofβwere found to bein the order of ∼ 10−7cm W−1, n2in the order of ∼10−12cm2W−1andχ3in the range 4.99 × 10−7– 38.7 × 10−7e.s.u. Further, the optical power limiting threshold was calculated to be 3.646 KW cm−2for 8 wt % of PS/ZnO nanocomposite foil which is a better candidate to act as an optical limiter. The figure of merit has also been determined that establishes the suitability of nanocomposite foils for optical limiting and/or optical switching applications in the visible region.
Doppler boosting the stochastic gravitational wave background
Authors: Cusin Giulia , Tasinato Gianmassimo
Published: August 2022

One of the guaranteed features of the stochastic gravitational wave background (SGWB) is the presence of Doppler anisotropies induced by the motion of the detector with respect to the rest frame of the SGWB source. We point out that kinematic effects can be amplified if the SGWB is characterised by large tilts in its spectrum as a function of frequency, or by sizeable intrinsic anisotropies. Hence we examine the possibility to use Doppler effects as complementary probes of the SGWB frequency profile. For this purpose we work in multipole space, and we study the effect of kinematic modulation and aberration on the GW energy density parameter and on its angular power spectrum. We develop a Fisher forecast analysis and we discuss prospects for constraining parameters controlling kinematically induced anisotropies with future detector networks. As a case study, we apply our framework to a background component with constant slope in frequency, potentially detectable by a network of future ground-based interferometers. For this specific example, we show that a measurement of kinematic anisotropies with a network of Einstein Telescope and Cosmic Explorer will allow us to constrain the spectral shape with a precision of about 16%. We also show that, if a reconstruction of the spectral shape is done via other methods, e.g. frequency binning, a study of kinematic anisotropies can allow one to constrain our peculiar velocity with respect to the CMB frame with a precision of 30%. Finally, we identify cosmological and astrophysical scenarios where kinematic effects are enhanced in frequency ranges probed by current and future GW experiments.
Distinguishing Dirac vs. Majorana neutrinos: a cosmological probe
Authors: Hernandez-Molinero Beatriz , Jimenez Raul , Peña Garay Carlos
Published: August 2022

Cosmic background neutrinos (CνB) helicity composition is different for Dirac or Majorana neutrinos making detectors based onCνBcapture sensitive to the nature of neutrinos. We calculate, for the first time, the helicity changes of neutrinos crossing dark matter fields, to quantitatively calculate this effect on the capture rate. We show that a fraction of neutrinos change their helicity, regardless of them being deflected by a void or a dark matter halo. The average signal from the 100 most massive voids or halos in a Gpc3gives a prediction that if neutrinos are Dirac, the density of theCνBbackground measured on Earth should be 48 cm-3for left-helical neutrinos, a decrease of 15% (53.6 cm-3; 5%) for a halo (void) with respect to the standard calculation without including gravitational effects due to large scale structures. In terms of the total capture rate in a 100 g tritium detector, this translates in 4.9+1.1-0.8neutrinos per year for the Dirac case, as a function of the unknown neutrino mass scale, or 8.1 per year if neutrinos are Majorana. Thus although smaller than the factor two for the non-relativistic case, it is still large enough to be detected and it highlights the power of futureCνBdetectors, as an alternative to neutrinoless double beta decay experiments, to discover the neutrino nature.
Duality-symmetric axion electrodynamics and haloscopes of various geometries
Authors: Le Dai-Nam , Hoang Le Phuong , Xuan Cao Binh
Published: August 2022

Within the dual symmetric point of view, the theory for seeking axion dark matter via haloscope experiments is derived by exactly solving the dual symmetric axion electrodynamics equation. Notwithstanding that the conventional theory of axion electrodynamics presented in [9,11] is more commonly used in haloscope theory, we show that the dual symmetric axion electrodynamics has more advantages to apply into haloscope theory. First, the dual symmetric and conventional perspective of axion electrodynamics coincide under long-wavelength approximation. Moreover, dual symmetric theory can obtain an exact analytical expression of the axion-induced electromagnetic field for any states of axion. This solution has been used in conventional theory for long-wavelength approximation. The difference between two theories can occur in directional axion detection or electric sensing haloscopes. For illustrative purposes, we consider the various type of resonant cavities: cylindrical solenoid, spherical solenoid, two-parallel-sheet cavity, toroidal solenoid with a rectangular cross-section, and with a circular cross-section. The resonance of the axion-induced signal as well as the ratio of the energy difference over the stored energy inside the cavity are investigated in these types of cavity.
On the effective metric of axial black hole perturbations in DHOST gravity
Authors: Langlois David , Noui Karim , Roussille Hugo
Published: August 2022

We study axial (or odd-parity) perturbations about static and spherically symmetric hairy black hole (BH) solutions in shift-symmetric DHOST (Degenerate Higher-Order Scalar-Tensor) theories. We first extend to the family of DHOST theories the first-order formulation that we recently developed for Horndeski theories. Remarkably, we find that the dynamics of DHOST axial perturbations is equivalent to that of axial perturbations in general relativity (GR) evolving in a, distinct, effective metric. In the particular case of quadratic DHOST theories, this effective metric is derived from the background BH metric via a disformal transformation. We illustrate our general study with three examples of BH solutions. In some so-called stealth solutions, the effective metric is Schwarzschild with a shifted horizon. We also give an example of BH solution for which the effective metric is associated with a naked singularity.
Lepton asymmetric universe
Authors: Kawasaki Masahiro , Murai Kai
Published: August 2022

The recent observation of4He implies that our universe has a large lepton asymmetry. We consider the Affleck-Dine (AD) mechanism for lepton number generation. In the AD mechanism, non-topological solitons called L-balls are produced, and the generated lepton number is confined in them. The L-balls protect the generated lepton number from being converted to baryon number through the sphaleron processes. We study the formation and evolution of the L-balls and find that the universe with large lepton asymmetry suggested by the recent4He measurement can be realized.
Effect of near



-symmetric potentials on nonlinear modes for higher-order generalized Ginzburg–Landau model
Authors: Lin Da , Dong Kai-Ru , Zhang Jia-Rui , Shen Yu-Jia
Published: August 2022

In this paper, we study the higher-order generalized Ginzburg–Landau model which contributes to describing the propagation of optical solitons in fibers. By means of the Hirota bilinear method, the analytical solutions are obtained and the effect of relevant parameters is analyzed. Modulated by the near parity-time-symmetric potentials, the nonlinear modes with 5% initial random noise are numerically simulated to possess stable evolution. Furthermore, the evolution of nonlinear modes is displayed through the adiabatical change of some parameters. The investigation of the present work is intended as a contribution to the work for the higher-order generalized Ginzburg–Landau model.
Four-stage cascaded variable optical attenuator with large attenuation range for quantum key distribution
Authors: Liu Qing-Hai , Pan Pan , You Jin , Zhang Jia-Shun , Wang Ya , Wang Yu-Ting , Wang Liang-Liang , An Jun-Ming , Cui Da-Jian , Zhou Lang , Chen Wei
Published: August 2022

A four-stage cascaded variable optical attenuator (VOA) with a large attenuation range is presented. The VOA is based on a Mach–Zehnder interferometer (MZI) and fabricated in a silica-based planar lightwave circuit (PLC) platform. The thermo-optic effect is used to achieve intensity modulation. The measured maximum attenuation of the four-stage cascaded VOA is 88.38 dB. The chip is also tested in a quantum key distribution (QKD) system to generate signal and decoy states. The mean photon number after attenuation of the four-stage cascaded VOA is less than 0.1, which can meet the requirement of QKD.
Angle-dependent spin wave spectra of permalloy ring arrays
Authors: Wu Shuxuan , Zhu Zengtai , Ma Yunxu , Wei Jinwu , Zhang Senfu , Wang Jianbo , Liu Qingfang
Published: August 2022

We investigated the angle-dependent spin wave spectra of permalloy ring arrays with the fixed outer diameter and various inner diameters by ferromagnetic resonance spectroscopy and micromagnetic simulation. When the field is obliquely applied to the ring, local resonance mode can be observed in different parts of the rings. And the resonance mode will change to perpendicular spin standing waves if the magnetic field is applied along the perpendicular direction. The simulation results demonstrated this evolution and implied more resonance modes that maybe exist. And the mathematical fitting results based on the Kittel equation further proved the existence of local resonance mode.
Bidirectional visible light absorber based on nanodisk arrays
Authors: Wang Qi , Zhu Fei-Fan , Li Rui , Zhang Shi-Jie , Zhang Da-Wei
Published: August 2022

A perfect bidirectional broadband visible light absorber composed of titanium nitride and tungsten nanodisk arrays is proposed. The average absorption of the absorber exceeds 89% at 400 nm–800 nm when light is normally incident on the front-side. Illumination from the opposite direction (back-side) results in absorption of more than 75%. Through the theoretical analysis of the electric and magnetic fields, the physical mechanism of the broadband perfect absorption is attributed to the synergy of localized surface plasmons, propagating surface plasmons, and plasmonic resonant cavity modes. Furthermore, the absorber also exhibits excellent polarization-independence performance and a high angular tolerance of ∼ 30° for both front- and back-side incidence. The designed bidirectional broadband visible light absorber here has wide application prospects in the fields of solar cells and ink-free printing.
Faint Space Debris Detection Algorithm Based on Small Aperture Telescope Detection System
Authors: Jiang Ping , Liu Chengzhi , Kang Zhe , Yang Wenbo , Li Zhenwei
Published: August 2022

Ground-based optical observation has unique advantages in space target observation. However, due to the weak light-gathering ability of small-aperture optoelectronic observation telescopes, the space debris in the image is weak and easily drowned in noise. In order to solve the above problems, we use digital image processing technology to extract faint space debris. We propose a high detection rate space debris automatic extraction algorithm, aiming to automatically detect space debris. We first establish a new space target description model. Our algorithm is mainly divided into two stages. The purpose of the first stage is to reduce the influence of a large number of stars. We perform wavelet transform and guided filtering for three consecutive frames, and the reconstructed wavelet that takes the median value can achieve the effect of eliminating stars. In the second stage, we adopt the method of robust principal component analysis and attribute the problem of target detection to the problem of separating the target and background of a single frame of image. After a large number of experimental results analysis, it is proved that the algorithm can effectively detect faint debris in the monitoring system of small aperture telescope, and has high precision and low computational complexity.
Decoding working memory-related information from repeated psychophysiological EEG experiments using convolutional and contrastive neural networks
Authors: Żygierewicz Jarosław , Janik Romuald A , Podolak Igor T , Drozd Alan , Malinowska Urszula , Poziomska Martyna , Wojciechowski Jakub , Ogniewski Paweł , Niedbalski Paweł , Terczynska Iwona , Rogala Jacek
Published: August 2022

Objective. Extracting reliable information from electroencephalogram (EEG) is difficult because the low signal-to-noise ratio and significant intersubject variability seriously hinder statistical analyses. However, recent advances in explainable machine learning open a new strategy to address this problem. Approach. The current study evaluates this approach using results from the classification and decoding of electrical brain activity associated with information retention. We designed four neural network models differing in architecture, training strategies, and input representation to classify single experimental trials of a working memory task. Main results. Our best models achieved an accuracy (ACC) of 65.29 ± 0.76 and Matthews correlation coefficient of 0.288 ± 0.018, outperforming the reference model trained on the same data. The highest correlation between classification score and behavioral performance was 0.36 (p = 0.0007). Using analysis of input perturbation, we estimated the importance of EEG channels and frequency bands in the task at hand. The set of essential features identified for each network varies. We identified a subset of features common to all models that identified brain regions and frequency bands consistent with current neurophysiological knowledge of the processes critical to attention and working memory. Finally, we proposed sanity checks to examine further the robustness of each model’s set of features. Significance. Our results indicate that explainable deep learning is a powerful tool for decoding information from EEG signals. It is crucial to train and analyze a range of models to identify stable and reliable features. Our results highlight the need for explainable modeling as the model with the highest ACC appeared to use residual artifactual activity.
Defects minimisation promoted by lead-volatility in (Pb,La)(Zr,Ti)O3ferroelectric ceramics
Authors: Silva A C , Mendez-González Y , Lima E C , Guerra J D S
Published: August 2022

La-modified PbZrTiO3ferroelectric ceramics with Pb0.92La0.08(Zr0.686Ti0.294)O3nominal composition were obtained via the conventional solid-state reaction method, by considering different PbO excess (5, 10 and 15 mol %). The structural properties, were investigated from X-ray diffraction (XRD) and Raman Spectroscopy techniques, both at room temperature. Results confirmed the formation of the perovskite structure with rhombohedral symmetry (R3mspace-group) for all the samples. The dielectric properties were also investigated, from the temperature dependence of the dielectric response, and results revealed the characteristic response of ferroelectric materials for all the compositions. The obtained very broad peak in the maximum dielectric permittivity, around Tm (~107°C), suggests the diffuse character of the ferroelectric-paraelectric phase transition.
Investigating the Structural and Electronic Properties of LiMO2 (M: Mn, Ni, Co) as Potential Cathode Materials: A DFT Study
Authors: Tsebesebe N.T. , Kgatwane K.M. , Ledwaba R.S. , Ngoepe P.E.
Published: August 2022

The layered transition metal oxides formulated LiMO2 (M: Mn, Ni and Co) are a state-of-art cathode material for lithium-ion batteries. They have attracted considerable attention due to their capability to optimize the capacity, cyclic rate, electrochemical stability, and lifetime. This paper reports the DFT+U calculations performed on LiMnO2, LiNiO2 and LiCoO2 materials. The heats of formations predict that the LiNiO2 is the most thermodynamically stable material while the LiMnO2 is the least thermodynamically stable material. The energy bandgap for LiNiO2 is relatively small suggesting that the material is high in conductivity. Conversely, the energy bandgaps of LiMnO2 and LiCoO2 are relatively wide suggesting that the materials are low in electrical conductivity. All independent elastic constants are positive and satisfying the mechanical stability criterion. Lastly, the phonon dispersion curves display imaginary vibration along high symmetry direction for LiCoO2. However, the material is inferred stable with support from the elastic constants. The LiNiO2 is the most stable material and LiCoO2 is the least stable material.
Alexandrite: investigation of a natural material for radiation dosimetry
Authors: Trindade N M , Nunes M C S , Dardengo S L , Silva A O , Kunzel R , Ulsen C , Yoshimura E M
Published: August 2022

In this work we performed experimental analyses of the dose-response curves of natural alexandrite, using thermoluminescence (TL) and optically stimulated luminescence (OSL). The natural alexandrite crystals from Bahia, Brazil, were pulverized and the optical absorption measurements were carried out in the range of 200 to 800 nm, comparing a non-irradiated sample with a 10 Gy beta irradiated one. OSL and TL measurements were performed using the Risø equipment (model DA-20) with irradiation doses from 1 to 5 Gy. Glow curve analysis was done using GlowFit software for TL, and R Studio software for OSL measurements. The irradiated sample (10 Gy) shows an absorption spectrum similar to the non-irradiated one, containing the same bands. The samples of natural alexandrite showed a linear dose-response for both OSL and TL measurements. From the TL and OSL analyses, it was possible to infer a correlation between the slow OSL component with the most intense TL peaks of alexandrite.
Surface net heat flux estimated from drifter observations
Authors: Wu Lingwei , Wang Guihua
Published: August 2022

The ocean mixed layer temperature equation is used to estimate the surface net heat flux from drifter measurements. The net heat flux is determined for both the climatologic and tropical cyclone (TC) conditions. The spatial distributions of the drifter-derived heat fluxes under both the two conditions are similar to those derived from satellite observations. However, the drifter-derived climatologic heat flux appears to be weaker in magnitude than that derived from satellites, and performs better in closing the energy budget with a global mean value of 3.9 W m−2. The drifter-derived heat flux also performs better than the satellite-derived heat flux under TCs, using the buoy observations as a reference considering metrics such as the meen error, mean absolute error, root mean-square error and percent bias. The spatially averaged mean net heat flux derived from drifters under TCs is −124 W m−2 at 10° N, and decreases to −85 W m−2 at 30° N, however, these values are much larger than those obtained from satellites (−63 W m−2 and −21 W m−2, respectively). As additional components for the mixed layer temperature equation, both the entrainment velocity and eddy diffusivity in climatology show large amplitudes in regions with strong currents such as the Western Boundary Current and Antarctic Circumpolar Current. However, under TC conditions large values of the entrainment velocity and eddy diffusivity mostly appear in regions with strong winds.
Screen-printed, erasable mask on filter membrane for silver nanowires patterning and application in flexible electroluminescent devices
Authors: Wang Jiayi , Lin Yong , Yuan Wei , Su Wenming , Cui Zheng
Published: August 2022

Silver nanowires (AgNWs) have been widely used in transparent conductive films (TCFs) for wearable optoelectronic devices due to their high transmittance, high conductivity. Mask-assisted vacuum filtration is a straightforward and effective patterning strategy for AgNWs with high aspect ratio. However, currently reported non-erasable masks result in the filter membrane being unable to be recycled, which greatly increase the manufacturing cost of patterned TCFs. Herein, we propose an improved method to construct an erasable mask on the filter membrane by screen printing polyvinyl alcohol (PVA) solution. The printed PVA mask is strongly attached to the filter membrane, which lead to the AgNWs pattern with smooth and distinct edges after vacuum filtration. The deposited AgNWs patterns can be transferred to the polydimethylsiloxane film by hot pressing to prepare the patterned TCFs. After the transfer, the printed PVA mask can be easily erased or cleaned from the filter membrane in hot water without damaging its pore structure, enabling the recycling of the filter membrane. As a proof, ten pieces of TCFs with square shape were prepared by recycling one filter membrane and all of them had excellent consistency in sheet resistance, optical transmittance and bending durability. Alternating current electroluminescence devices made from the TCFs were consistent in luminance, emission spectrum and Commission Internationale de l’eclairage coordinates. The erasable mask technique can be extended to patterning process of various nanomaterials other than AgNWs under vacuum filtration to enhance the utilization efficiency of filter membrane and to reduce the manufacturing cost.
Bibliometric analysis and systematic review of environmental, social, and governance disclosure papers: current topics and recommendations for future research
Authors: Ellili Nejla Ould Daoud
Published: August 2022

This study analyzes the literature on environmental, social, and governance (ESG) disclosure by applying a bibliometric analysis of documents published in the Scopus database. The bibliometric analysis allows researchers to highlight the theoretical foundations of a specific research field, identify the main findings of previous studies, and determine future research ideas. This analysis was based on bibliometric authors’ citation analysis, bibliometric papers’ co-citation analysis, bibliometric references’ co-citation analysis, bibliometric journals’ co-citation analysis, co-occurrence keywords cartography analysis, trend and evolution analyses of ESG disclosure publications over the years, and qualitative content analysis. This study reviews 161 documents on ESG disclosure published in the Scopus database. Bibliometric analysis was conducted using VOSviewer, evolution analysis was performed using CiteSpace, and content analysis was performed using Wordstat. The study identified four major clusters: corporate social responsibility, corporate strategy, financial performance, and environmental economics. It also highlights the increasing number of citations and documents related to ESG disclosures. In addition, the journal ‘Business Strategy and the Environment’ significantly contributes to the ESG disclosure research field in terms of number of papers and citations. Additionally, this study highlights various future research opportunities in this field. The findings of this study have practical implications for ESG disclosure, such as the impact of integrating ESG into a company’s business strategy on corporate and financial policies. This study is the only one to review key topics on ESG disclosure that can be largely used for ESG practices. This study provides an overview of how the literature on ESG disclosure has developed, as well as a summary of the most influential authors along with countries, organizations, and journal sources. This offers the opportunity for future research to focus on this topic.
Preprint Highlight: Evolution of selfish multicellularity collective organisation of individual spatio-temporal regulatory strategies
Authors: De Lora Jacqueline A.
Published: August 2022

In origins-of-life studies, how interactions between unicellular individuals give rise to multicellular organisms is an open question. Presumably, the evolution of cell adhesion enables responses to emergent selection pressures, driving cell collective formation, and migration. This study implements a multiscale computational model of unicellular individuals possessing regulatory gene networks and evolvable adhesion proteins, or not, within changing environments. In an initial environment that is resource limited, cells with evolvable adhesions divide first and migrate as a cluster later, exploiting cooperativity to move toward resource-abundant locations as a collective while maximizing lineage propagation. This link between the evolution of resource competition dynamics and cellular adhesion interactions provides insight into how unicellular ancestors might have made the progression to multicellular collectives.
Preprint Highlight: Real-time denoising of fluorescence time-lapse imaging enables high-sensitivity observations of biological dynamics beyond the shot-noise limit
Authors: Takao Daisuke
Published: August 2022

Denoising in fluorescence imaging is a key technology to boost sensitivity and detect low signals buried in noise. While previous deep learning-based algorithms have been demonstrated to improve denoising quality, their application has been limited by the time-consuming processing step. This study demonstrates a much faster deep learning-based denoising algorithm, DeepCAD-RT, that enables real-time processing of fluorescence live cell images and can be incorporated into the data acquisition pipeline of a microscopy system. In addition to its obvious advantage in improving workflow efficiency, DeepCAD-RT could also have an impact on robotics technologies, such as automatic microinjection and cell picking, that require highly sensitive and real-time recognition of cells under a microscope.
Exiles, Migrants, and Refugees
Authors: Goyal Yogita
Published: August 2022

The introduction to this special issue argues that new work on borders and refugees does not simply serve as an urgent response to contemporary politics but requires an unsettling of core conceptions of nation and empire, citizenship and migrancy, and rights and rightlessness. Prioritizing the perspectives of exiles, migrants, and refugees entails new understandings of the relationship between mutating racial formations and international border regimes across past and present landscapes. Reading the refugee necessitates rethinking belonging in order to expand our political imagination beyond anodyne notions of multiculturalism or liminality. Such work undoes American Studies from the inside rather than institutionalizing a distinct sub-field of border studies. Recognizing that the border is everywhere, and is not limited to the construction of a wall or checkpoint, such study strives to undo the exceptionality of the border as a site to link the practices of surveillance, capture, and detention that operate there to similar practices within the domestic sphere.

An attempt to grasp US literary history from the vantage of exiles, migrants, and refugees is not timely, but fundamentally belated—impossible to arrive at and long overdue.
Ante-Possession: A History of Dispossession’s Present
Authors: Kazanjian David
Published: August 2022

This article examines efforts by the dispossessed to challenge dispossession without claiming prior possession or demanding renewed possession as a singular remedy. It juxtaposes the author’s work as a volunteer advocate for migrants detained in El Paso, Texas, with late seventeenth-century records of the trial of an enslaved Black man named Juan Patricio for assaulting a priest after helping a Maya woman named Fabiana Pech, in Yucatán, Mexico. This juxtaposition reveals a long history of dispossession and Black and Indigenous challenges to it, as well as a method for reading that history by attending to the poiesis of the archive, or the manner in which sources imaginatively remake what we know and how we act in ways that are not dependent upon the willful volition of individual actors. The article proposes a shift away from theories of dispossession that presuppose prior possession and toward a theory of ante-possession: lives lived prior to, in opposition to, or in apposition to possession as such.

“We could call these social relations ante-possessive to capture the many ways they thrive before, against, or alongside racial capitalist modes of possession.”
Security, Exile, Population: Colonization from David Walker to the Liberia Herald
Authors: Castronovo Russ
Published: August 2022

By looking at colonization at white responses to Black population increase in the US, this essay argues that exile and other biopolitical mechanisms undo the logic of security by showing how the search for safety itself generates and amplifies insecurity. Framed against contemporary meditations on exile, the essay examines how whites presented the deportation of US Blacks to Liberia as a solution to a national security crisis. In response, Black activists and writers such as James Forten and Russell Parrott demonstrated how white concerns created insecurity among the US Black population. To offset the vulnerability of exile that other colonizationists mandated for Black people, the use of racial arithmetic in Freedom’s Journal, the first African American newspaper, and by David Walker shows that security for Blacks can be achieved, at least rhetorically, by mobilizing biopower and exploiting arithmetical ratios of Blacks to whites. In a twist, however, the editor of Freedom’s Journal, John Russwurm, emigrated to West Africa to publish the Liberia Herald whose columns reveal how in the exile’s safe haven racial differences upheld by the US continued to have meaning. In exile, security and insecurity remained twined about each other in cycles of violence.

Extermination is population security at its most absolute. . . . if the problem of security is the population’s ceaseless potential for being born, reproducing, and dying, then, exile and colonization serve as technologies for radically altering the polity in the name of national interest.
Anti-phytopathogenic-bacterial fatty acids from the mycelia of the edible mushroom Agaricus blazei
Authors: Wang Junhong , Wu Jing , Ogura Ryuhei , Kobori Hajime , Choi Jae-Hoon , Hirai Hirofumi , Takikawa Yuichi , Kawagishi Hirokazu
Published: August 2022

Five compounds including a new compound (1) were isolated from mycelia of a mushroom-forming fungus Agaricus blazei. Compound 2 was isolated from nature for the first time. Their structures were determined by the interpretation of spectroscopic data. In the bioassay examining growth inhibitory activity against phytopathogenic bacteria Clavibacter michiganensis, Burkholderia glumae, and Peptobacterium carotovorum, all the compounds showed inhibition effects on C. michiganensis. Compounds 3 and 4 also showed weak inhibitory activity against growth of B. glumae.
Blue flower coloration of Salvia macrophylla by the metalloanthocyanin, protodelphin
Authors: Yoshida Kumi , Teppabut Yada , Sugita Chieko , Oyama Kin-ichi
Published: August 2022

A survey of metalloanthocyanin by in vivo visible spectrum and circular dichroism suggested that blue petals of Salvia macrophylla contain metalloanthocyanins. Chemical analysis of the purified blue pigment proved that the pigment in the petals is protodelphin, which is the same pigment present in the blue petals of Salvia patens composed of malonylawobanin, apigenin 7,4′-diglucosides and Mg2+.
A Bayesian framework for incorporating exposure uncertainty into health analyses with application to air pollution and stillbirth
Authors: Comess Saskia , Chang Howard H , Warren Joshua L
Published: August 2022

Studies of the relationships between environmental exposures and adverse health outcomes often rely on a two-stage statistical modeling approach, where exposure is modeled/predicted in the first stage and used as input to a separately fit health outcome analysis in the second stage. Uncertainty in these predictions is frequently ignored, or accounted for in an overly simplistic manner when estimating the associations of interest. Working in the Bayesian setting, we propose a flexible kernel density estimation (KDE) approach for fully utilizing posterior output from the first stage modeling/prediction to make accurate inference on the association between exposure and health in the second stage, derive the full conditional distributions needed for efficient model fitting, detail its connections with existing approaches, and compare its performance through simulation. Our KDE approach is shown to generally have improved performance across several settings and model comparison metrics. Using competing approaches, we investigate the association between lagged daily ambient fine particulate matter levels and stillbirth counts in New Jersey (2011–2015), observing an increase in risk with elevated exposure 3 days prior to delivery. The newly developed methods are available in the R package KDExp.