bluuebunny/crossref_metadata_2025 huggingface dataset:
Obtaining thermal images of creole corn by means of photoacoustic microscopy
Authors: Dominguez-Pacheco A. , Hernandez-Aguilar C. , Cruz-Orea A.
Published: June 2022

The use of non-destructive techniques, such as photothermal techniques, can be used for characterization of non-homogeneous materials with different components and thermophysical properties. Among the photothermal techniques, the photoacoustic microscopy (PAM) has been used to obtain thermal images of different samples, ranging from semiconductors to biological materials. In the present study, the thermal imaging of six different creole corn varieties was obtained by using PAM. According to the color, these varieties were nominated as M1 (orange–yellow), M2 (blue), M3 (blue), M4 (light yellow), M5 (yellow), and M6 (red). Thermal images allowed us visualize corn characteristic features and structures, with higher values of photoacoustic signal amplitude in floury regions and pedicel. The highest values of photoacoustic signal amplitude corresponded to M1 (0.39), M6 (0.35), and M5 (0.34) corn samples, followed by M4 sample. Also, colorimetric parameters L*a* and b* of the creole corn samples were evaluated, and they showed significant statistical differences (p < 0.5). The colorimetric results were analyzed by the statistical method of Kernel density estimation, showing a higher density of data in the B component, followed by R and G. The non-destructive techniques allow characterizing non-homogeneous materials with different components. Thermal images, obtained by using PAM, can be analyzed by several statistical methods.
Coexistence of ferroelectric phases in barium titanate single-domain thin films
Authors: Baudry Laurent
Published: June 2022

In about twenty years, the temperature-misfit strain phase diagrams have become valuable tools to describe ferroelectric thin film properties. The background theoretical approach consists in searching for the position of the global minimum of the potential landscape and deducing the thermodynamically stable phase. In temperature-misfit strain phase diagrams, lines separate the stable phase regions, and the analysis of the polarization continuity properties across these lines allows us to determine the order of phase transition. This work revealed additional important information relative to the properties of first order phase transitions; we determined the limit of stability of the metastable phases and plotted the corresponding lines in the traditional temperature-misfit strain diagrams. These one dimensional boundaries are the analog to the superheating and supercooling temperature points in the context of bulk ferroelectric crystal. We highlight two dimensional coexistence regions adjacent to first order thermodynamic transition lines. The location and the shape of these regions are strongly dependent on the set of parameters used to describe the bulk crystal. We illustrate the interest in the revelation of coexistence regions, showing that the corresponding multi-stability properties could be used to design non-binary memory cells by using barium titanate thin films.
Dual-mode microresonators as straightforward access to octave-spanning dissipative Kerr solitons
Authors: Weng Haizhong , Afridi Adnan Ali , Li Jing , McDermott Michael , Tu Huilan , Barry Liam P. , Lu Qiaoyin , Guo Weihua , Donegan John F.
Published: June 2022

The Kerr soliton frequency comb is a revolutionary compact ruler of coherent light that allows applications from precision metrology to quantum information technology. The universal, reliable, and low-cost soliton microcomb source is key to these applications. As a development and extension of the direct creation of a soliton microcomb with the dual-mode scheme in an aluminum nitride microresonator, this paper thoroughly presents the design strategy to reliably attain such dual-modes in the silicon nitride (Si3N4) platform, separated by ∼10 GHz, which stabilizes soliton formation without using additional auxiliary laser or RF components. We demonstrate the deterministic generation of the refined single-solitons that span 1.5-octaves, i.e., near 200 THz, via adiabatic pump wavelength tuning. The ultra-wide soliton existence range up to 17 GHz not only suggests the robustness of the system but will also extend the applications of soliton combs. Moreover, the proposed scheme is found to easily give rise to multi-solitons as well as the soliton crystals featuring enhanced repetition rate (2 and 3 THz) and conversion efficiency greater than 10%. We also show the effective thermal tuning of mode separation to increase the possibility to access the single-soliton state. Our results are crucial for the chip-scale self-referenced frequency combs with a simplified configuration.
Transient surface photovoltage spectroscopy of diamond
Authors: Dittrich Th.
Published: June 2022

Contactless and highly sensitive probing of electronic transitions in diamond over a wide spectral range from near infrared to deep ultraviolet is still challenging. Surface photovoltage (SPV) signals depend on electronic transitions and transport phenomena leading to charge separation in space and allow for a contactless study of electronic transitions. Here, transient SPV spectroscopy in an arrangement with a charge amplifier and a laser tunable over a wide range was applied to study an undoped diamond single crystal between 0.8 and 5.9 eV at room temperature in ambient air. SPV transients were measured without and with weak visible bias light, which allowed for suppression of possible parasitic contributions in SPV signals not related to diamond and distinction of processes of charge separation that were independent of band bending. Transitions at 1.0 and 3.1 eV led to preferential separation of photogenerated holes toward the surface. In contrast, a transition at 1.8 eV caused preferential separation of photogenerated electrons toward the surface. Transitions near the indirect bandgap of diamond were observed at 5.27, 5.32, 5.48, and 5.53 eV and could be assigned to absorption assisted (i) by an indirect exciton and absorption of longitudinal optical and acoustic phonons, (ii) by absorption of transverse acoustic phonons, (iii) by emission of transverse acoustic phonons, and (iv) by emission of longitudinal optical and acoustic phonons, respectively. Charge separation under excitation at 5.27 eV was caused by directed charge transfer at/near the diamond surface after exciton diffusion followed by exciton dissociation.
Interplay of diffusio- and thermo-osmotic flows generated by single light stimulus
Authors: Muraveva Valeriia , Bekir Marek , Lomadze Nino , Großmann Robert , Beta Carsten , Santer Svetlana
Published: June 2022

Flow control is a highly relevant topic for micromanipulation of colloidal particles in microfluidic applications. Here, we report on a system that combines two-surface bound flows emanating from thermo-osmotic and diffusio-osmotic mechanisms. These opposing flows are generated at a gold surface immersed into an aqueous solution containing a photo-sensitive surfactant, which is irradiated by a focused UV laser beam. At low power of incoming light, diffusio-osmotic flow due to local photo-isomerization of the surfactant dominates, resulting in a flow pattern oriented away from the irradiated area. In contrast, thermo-osmotic flow takes over due to local heating of the gold surface at larger power, consequently inducing a flow pointing toward the hotspot. In this way, this system allows one to reversibly switch from outward to inward liquid flow with an intermittent range of zero flow at which tracer particles undergo thermal motion by just tuning the laser intensity only. Our work, thus, demonstrates an optofluidic system for flow generation with a high degree of controllability that is necessary to transport particles precisely to desired locations, thereby opening innovative possibilities to generate advanced microfluidic applications.
Effect of amplitude and wavelength in the cooperative motion of Taylor lines
Authors: Khan Mohd Yasir , Babu Sujin B.
Published: June 2022

In the present study, we have modeled the clustering of binary Taylor line swimmers in a Newtonian fluid. The fluid is modeled using the particle-based simulation method multiparticle collision dynamics, while for the Taylor line, we use a bead spring arrangement with a sine wave passing through it using a bending wave potential. The binary swimmers have the same propulsion speed, but they differ from each other in the shape of the Taylor line ensured by different amplitudes and lengths. We observe that an optimal amplitude exists for the Taylor line swimmer leading to large clusters formation. The size distribution of the clusters was observed to follow a power-law behavior followed by an exponential cutoff. We also calculated the probability of finding a bead of the swimmer as a function of the fractional distance from the center of the bounding circle and observed that when the amplitude is close to the optimal value, the swimmer forms clusters closer to the walls; otherwise, the swimmer stays almost uniformly distributed around the bounding area. When the ratio of the amplitude is high, the clusters formed at the center of the bounding area become stable and have a wedge-shape. By calculating the speed of the swimmer as a function of the fractional distance from the center of the bounding area, we show that the swimmers speed increases with the maximum at the walls. The simulation with a smaller system has revealed that the maximum clustering happens for an amplitude parameter of ∼0.17.
Fabrication of multi-channel filter array mold based on fast tool servo turning
Authors: Huang Yuetian , Li Shijie , Zhang Jin , Yang Chen , Liang Haifeng
Published: June 2022

To realize a multi-channel integrated filter on a single substrate, a new preparation method is proposed in this paper, which was to adjust the thickness of the space layer based on the Fabry–Pérot interferometer theory. Optical thickness adjustment is achieved by integrating multispectral channels on a single substrate that is fabricated combined with coating, nanoimprinting, and single point diamond turning. A multi-channel filter is integrated on a mold and machined once, and three kinds of multi-channel array filter molds are fabricated utilizing fast tool servo turning. The accuracy of each channel is analyzed for the machine accuracy of the mold, which affords the key to this method. Although there exists a slight oscillation error on the surface of each channel, the maximum error is less than 4 nm and the ratio of error and differentials designed is less than 7%. The results indicate that the processing method of the multi-channel filter mold is feasible. As far as this technology is concerned, it provides technical support for mass manufacturing of large-scale multi-channel array filters.
Laser cooling and electronic structure of Be halide anions BeX− (X = Cl, Br, F, and I)
Authors: Madi Amal , El-Kork Nayla , Zeid Israa , Korek Mahmoud
Published: June 2022

The adiabatic potential energy curves of the low lying electronic states of the Be halide anions BeX− (Cl, Br, F, and I) have been investigated in the representation 2s+1Λ(+/−) by using the complete active space self-consistent field with a multireference configuration interaction method. The spectroscopic parameters Te, Re, ωe, and Be and the static and transition dipole moment μe were studied, and a rovibrational study of the investigated electronic states was performed. New electronic states were investigated here for the first time. The calculated highly diagonal Franck–Condon factor and the short radiative lifetime among the lowest vibrational levels of the X1Σ0+ − (1)3Π1 transitions of the molecular anion BeF− prove its candidacy for Doppler laser cooling. The experimental proof of the stability and the calculated experimental parameters, such as the vibrational branching ratio, the slowing distance, the recoil, and Doppler temperatures with the experimental conditions of the buffer gas cell of this anion, open the route for experimental work on the BeF− molecular ion.
Electron transport properties of a narrow-bandgap semiconductor Bi2O2Te nanosheet
Authors: Li Xiaobo , Su Haitian , Xu H. Q.
Published: June 2022

A thin, narrow-bandgap semiconductor Bi2O2Te nanosheet is obtained via mechanical exfoliation, and a Hall-bar device is fabricated from it on a heavily doped Si/SiO2 substrate and studied at low temperatures. Gate transfer characteristic measurements show that the transport carriers in the nanosheet are of n-type. The carrier density, mobility, and mean free path in the nanosheet are determined by measurements of the Hall resistance and the longitudinal resistance of the Hall-bar device, and it is found that the electron transport in the nanosheet is in a quasi-two-dimensional (2D), strongly disordered regime. Magnetotransport measurements for the device at magnetic fields applied perpendicular to the nanosheet plane show dominantly weak antilocalization (WAL) characteristics at low fields and a linear magnetoresistance (LMR) behavior at high fields. We attribute the WAL characteristics to strong spin–orbit interaction (SOI) and the LMR to the classical origin of strong disorder in the nanosheet. Low-field magnetoconductivity measurements are also performed and are analyzed based on the multi-channel Hikami–Larkin–Nagaoka theory with the LMR correction being taken into account. The phase coherence length, spin relaxation length, effective 2D conduction channel number, and coefficient in the linear term due to the LMR in the nanosheet are extracted. It is found that the spin relaxation length in the Bi2O2Te nanosheet is several times smaller than that in its counterpart Bi2O2Se nanosheet, and thus, an ultra-strong SOI is present in the Bi2O2Te nanosheet. Our results reported in this study would greatly encourage further studies and applications of this emerging narrow-bandgap semiconductor 2D material.
Phonon decay in BaSnO3 perovskite
Authors: Neupane Chandra P. , Sylvester Jeremy , Xu Xianghan , Cheong Sang-Wook , Ganikhanov Feruz
Published: June 2022

Time-domain coherent Raman techniques have been utilized to selectively measure ultrafast decay rates of optical phonons in cubic BaSnO3 perovskite. Measurements were made within a 350–1300 cm−1 frequency range with time and equivalent spectral resolution of ∼120 fs and less than 0.1 cm−1, respectively. The phonon mode damping rates are found to be within 1.27–1.59 ps−1 at room temperature, indicating that the homogeneously broadened Raman linewidths are within 6.7–8.4 cm−1. Phonon decay mechanisms are being discussed within the framework of parametric phonon interactions due to lattice anharmonicity. Characteristics of the Raman active modes are essential in understanding the limiting factors for achieving high carrier mobility in device applications of the material.
Spectral features of the wake and power fluctuations of model wind turbines under low-level jets
Authors: Evans Humberto Bocanegra , Doosttalab Ali , Siguenza-Alvarado Diego , Cheng Shyuan , Chamorro Leonardo P. , Castillo Luciano
Published: June 2022

Laboratory experiments are conducted to inspect the modulation of model low-level-jet (LLJ) velocity profiles on the wake of a model wind turbine and power output fluctuations and a spectral structure of a simple two-turbine system in an aligned configuration. The scenario with a canonical incoming turbulent boundary layer profile is included for comparison. The results reveal a significant effect of the relative height of the LLJ peak velocity on the near and intermediate wake and power output fluctuations. Those effects are more notorious with the LLJ peak velocity coincident with the turbine top tip. The strong mean shear right above the wake promotes enhanced vertical transport and generation of energetic coherent motions. In particular, the near and intermediate wake velocity spectra showed a robust local signature with a streamwise length on the order of ∼4 times the rotor diameter. Although this shear layer did not significantly affect the spectrum of the power output fluctuations, the relatively large-scale velocity fluctuations may affect wind turbines' downwind in arrays.
Boron nitride neutron detector with the ability for detecting both thermal and fast neutrons
Authors: Tingsuwatit A. , Maity A. , Grenadier S. J. , Li J. , Lin J. Y. , Jiang H. X.
Published: June 2022

The detection of fast neutrons is regarded technically challenging because the interaction probability of fast neutron with matter is extremely low. Based on our recent development of hexagonal boron nitride (BN) semiconductor thermal neutron detectors with a record high efficiency of 59%, we report here the feasibility studies of BN detectors for detecting fast neutrons. A BN detector with a detection area of 2.1 cm2 was fabricated from a 90 μm thick BN epilayer. In the presence of a bare Cf-252 source emitting fast neutrons ranging from 1 to 9 MeV, the detection efficiency was estimated to be about 0.1%. The measured mean free path of fast neutron in BN is about 7.6 cm. Together with the capability of BN for thermal neutron detection, the present results indicate that by incorporating BN with a large thickness, BN neutron detectors are expected to possess the unique capability of directly detecting thermal to fast neutrons as well as outstanding features resulting from the ultrawide bandgap of BN. The identification of a single material that is sensitive to both thermal and fast neutrons is valuable for the development of novel neutron detection technologies.
Spatially composition-graded monolayer tungsten selenium telluride
Authors: Xu Kai , Hao Zheng , Alsalman Hussain , Kang Junzhe , Chen Changqiang , Wang Zhiyu , Zhao Zijing , Low Tony , Zhu Wenjuan
Published: June 2022

Heterogeneous materials with spatially modulated bandgaps have many unique applications, such as super-broadband nanolasers, color engineered displays, hyperspectral detectors, and full spectrum solar cells. In this work, spatially composition-graded WSe2 − 2xTe2x flakes are synthesized through an in situ chemical vapor deposition method. Furthermore, a monolayer flake topography is confirmed by atomic force microscopy. Photoluminescence and Raman line-scanning characterization indicate the bandgap changes continuously from center (1.46 eV) to edge (∼1.61 eV) within a monolayer flake. Electronic devices based on this spatially composition-graded material exhibit tunable transfer curves. First principal calculation reveals that the electron affinity increases, while the bandgap decreases based on tellurium composition. This is consistent with experimentally observed non-monotonic dependence of the hole current on tellurium composition. This work provides the experimental groundwork for synthesis of the composition-graded transition metal dichalcogenide materials and offers a route toward tailoring their electrical properties by bandgap engineering in the future.
Influence of the Hall current on the convective and magnetorotational instability in a thin layer of an electrically conductive nanofluid
Authors: Kopp M. I. , Yanovsky V. V.
Published: June 2022

This study investigates the combined influence of the Hall current and the axial magnetic field on the criterion for the onset of convection in a nonuniformly rotating layer of electrically conductive nanofluids taking into account the effects of Brownian diffusion and thermophoresis. The analytical and numerical computations are presented for water-based nanofluids with alumina nanoparticles. In the absence of a temperature gradient, a new type of magnetorotational instability in an axial magnetic field in a thin layer of a nanofluid is considered. The growth rate and regions of development of this instability are numerically obtained depending on the angular velocity profile (the Rossby number Ro) and the radial wavenumber k. In the presence of temperature and nanoparticle concentration gradients, the stationary regime of nonuniformly rotating magnetoconvection is studied. The exact analytical expression for critical Rayleigh number Rast is obtained in terms of various nondimensional parameters. The results indicate that the increase in the Lewis number, the modified diffusivity ratio, and the concentration Rayleigh number is to accelerate the onset of convection. The increase in the Hall current parameter can delay or enhance the onset of convective instability. Rotation profiles with negative Rossby numbers lower the threshold for the development of thermal instability and stimulate the onset of convection. The conditions for stabilization and destabilization of stationary convection in an axial magnetic field are determined. The results are represented graphically and verified numerically.
Collective dynamics in a glass-former with Mari–Kurchan interactions
Authors: Nishikawa Yoshihiko , Ikeda Atsushi , Berthier Ludovic
Published: June 2022

We numerically study the equilibrium relaxation dynamics of a two-dimensional Mari–Kurchan glass model. The tree-like structure of particle interactions forbids both nontrivial structural motifs and the emergence of a complex free-energy landscape leading to a thermodynamic glass transition, while the finite-dimensional nature of the model prevents the existence of a mode-coupling singularity. Nevertheless, the equilibrium relaxation dynamics is shown to be in excellent agreement with simulations performed in conventional glass-formers. Averaged time correlation functions display a phenomenology typical of supercooled liquids, including the emergence of an excess signal in relaxation spectra at intermediate frequencies. We show that this evolution is accompanied by strong signatures of collective and heterogeneous dynamics that cannot be interpreted in terms of single particle hopping and emerge from dynamic facilitation. Our study demonstrates that an off-lattice interacting particle model with extremely simple structural correlations displays quantitatively realistic glassy dynamics.
Electrically tunable WGM lasing in a metal-dielectric core–shell hybrid microcavity
Authors: Ge Kun , Niu Ben , Liu Fangyuan , Ruan Jun , Xu Zhiyang , Guo Dan , Wang Xiaolei , Lv Linzheng , Zhai Tianrui
Published: June 2022

We present a hybrid cavity designed to manipulate lasing modes, consisting of a metal-dielectric core–shell hybrid microcavity fabricated using a simple brush-coating method. Single and multiple modes can be obtained in the proposed laser device by the trade-off between loss and gain. Moreover, we achieve electrically tunable whispering-gallery-mode lasing by employing the thermo-optic effect in the hybrid microcavity. The lasing peak of the modes can be electrically tuned by quantitative control of Joule heating. We measure a tuning rate of 15.3 pm/J for all the lasing peaks.
Off-axis electron holography for the direct visualization of perpendicular shape anisotropy in nanoscale 3D magnetic random-access-memory devices
Authors: Almeida Trevor P. , Palomino Alvaro , Lequeux Steven , Boureau Victor , Fruchart Olivier , Prejbeanu Ioan Lucian , Dieny Bernard , Cooper David
Published: June 2022

Perpendicular shape anisotropy (PSA) and double magnetic tunnel junctions (DMTJs) offer practical solutions to downscale spin-transfer-torque Magnetic Random-Access Memory (STT-MRAM) beyond 20 nm technology nodes, while retaining their thermal stability and reducing critical currents applied. However, as these modern devices become smaller and three-dimensionally (3D) complex, our understanding of their functional magnetic behavior is often indirect, relying on magnetoresistance measurements and micromagnetic modeling. In this paper, we review recent work that was performed on these structures using a range of advanced electron microscopy techniques, focusing on aspects specific to the 3D and nanoscale nature of such elements. We present the methodology for the systematic transfer of individual SST-MRAM nano-pillars from large-scale arrays to image their magnetic configurations directly using off-axis electron holography. We show that improved phase sensitivity through stacking of electron holograms can be used to image subtle variations in DMTJs and the thermal stability of <20 nm PSA-STT-MRAM nano-pillars during in situ heating. The experimental practicalities, benefits, and limits of using electron holography for the analysis of MRAM devices are discussed, unlocking practical pathways for direct imaging of the functional magnetic performance of these systems with high spatial resolution and sensitivity.
High-performance broadband photodetector based on PdSe2/black phosphorus heterodiode
Authors: Dong Qingsong , Wang Fang , Hu Xin , Lu Yuan , Zhao Dongxu , Zhang Min , Han Tao , Hou Xingyuan , Wang Shaoliang , Long Mingsheng , Shan Lei
Published: June 2022

Uncooled long-wavelength infrared photodetectors based on two-dimensional materials have wide applications, such as remote sensing, missile guide, imaging, and night vision. However, realizing high-performance photodetectors based on 2D materials with high photoresponsivity and fast response speed is still a challenge. Here, we report an ultra-broadband photodetector based on the PdSe2/BP van der Waals heterodiode with a fast response speed. The detection range of the PdSe2/BP heterodiode is covered from visible to long-wave infrared (0.4–10.6 μm). A high photoresponsivity of 116.0 A/W and a low noise equivalence power of 8.4 × 10−16 W/Hz1/2 and D* of 2.05 × 109 cm Hz1/2/W were demonstrated. Notably, the heterodiode exhibits a very fast response speed with τr = 2.9 and τd = 4.0 μs. Our results introduced a promising application in broadband and fast photoresponse at weak light intensity.
Multireference configuration interaction study of the predissociation of C2 via its F1Π
u state
Authors: Xu Zhongxing , Federman S. R. , Jackson William M. , Ng Cheuk-Yiu , Wang Lee-Ping , Crabtree Kyle N.
Published: June 2022

Photodissociation is one of the main destruction pathways for dicarbon (C2) in astronomical environments, such as diffuse interstellar clouds, yet the accuracy of modern astrochemical models is limited by a lack of accurate photodissociation cross sections in the vacuum ultraviolet range. C2 features a strong predissociative F1Πu−X1Σg+ electronic transition near 130 nm originally measured in 1969; however, no experimental studies of this transition have been carried out since, and theoretical studies of the F1Πu state are limited. In this work, potential energy curves of excited electronic states of C2 are calculated with the aim of describing the predissociative nature of the F1Πu state and providing new ab initio photodissociation cross sections for astrochemical applications. Accurate electronic calculations of 56 singlet, triplet, and quintet states are carried out at the DW-SA-CASSCF/MRCI+Q level of theory with a CAS(8,12) active space and the aug-cc-pV5Z basis set augmented with additional diffuse functions. Photodissociation cross sections arising from the vibronic ground state to the F1Πu state are calculated by a coupled-channel model. The total integrated cross section through the F1Πu v = 0 and v = 1 bands is 1.198 × 10−13 cm2 cm−1, giving rise to a photodissociation rate of 5.02 × 10−10 s−1 under the standard interstellar radiation field, much larger than the rate in the Leiden photodissociation database. In addition, we report a new 21Σu+ state that should be detectable via a strong 21Σu+−X1Σg+ band around 116 nm.
Scaling patch analysis of planar turbulent wakes
Authors: Wei Tie , Livescu Daniel , Liu Xiaofeng
Published: June 2022

A scaling patch approach is used to investigate the proper scales in planar turbulent wakes. A proper scale for the mean axial flow is the well-known maximum velocity deficit Uref=U∞−Uctr, where U∞ is the free stream velocity and Uctr is the mean axial velocity at the wake centerline. From an admissible scaling of the mean continuity equation, a proper scale for the mean transverse flow is found as Vref=(dδ/dx)Uref, where dδ/dx is the growth rate of the wake width. From an admissible scaling of the mean momentum equation, a proper scale for the kinematic Reynolds shear stress is found as Ruv,ref=U∞Vref, which is a mixed scale of the free stream velocity and the mean transverse flow scale. Expressions are derived for the scaled mean transverse velocity and Reynolds shear stress in the far field of planar turbulent wakes. Using a Gaussian function for the mean axial velocity deficit, approximate functions for the scaled mean transverse velocity and Reynolds shear stress are developed and found to agree well with experimental and simulation data. This work reveals that the mean transverse flow, despite its small magnitude, plays an important role in the scaling and understanding of the planar turbulent wake.
A detection method for impact point water columns based on improved YOLO X
Authors: Wang Zhi , Shi Zhangsong , Tong Jijin , Gong Wenbin , Wu Zhonghong
Published: June 2022

This paper proposes an improved method to accurately and expediently detect water columns at the shells’ impact point. The suggested method combines a lightweight depthwise convolutional neural network (MobileNet v3) with the You Only Look Once X (YOLO X) algorithm, namely, YOLO X-m (MobileNet v3) that aims to simplify the network’s structure. Specifically, we used a weighted average pooling network and a spatial pyramid pooling network comprising multiple convolutional layers to retain as many features as possible. Moreover, we improve the activation and loss functions to reduce network calculations and afford better precision as well as fast and accurate water column detection. The experimental results reveal that YOLO X-m (MobileNet v3) ensures a good detection performance and adaptability to various light intensities, distances, and multiple water columns. Compared with the original YOLO X-m model, the improved network model achieves a 75.76% frames per second improvement and a 71.11% capacity reduction, while its AP50 decreases by only 1.29%. The proposed method is challenged against the single shot multibox detector and various YOLO variants, revealing its appealing accuracy, real-time detection performance, and suitability for practical applications and projects.
Microwave magnetic field strength imaging based on Rabi resonance with alkali-atom vapor cell
Authors: Chen Lang , Yao Minghao , Shi Yang , Duan Junyi , Kang Songbai , Wang Pengfei , Yu Zhilong , Guo Shuo , Liu Xiaochi
Published: June 2022

The present Rabi resonance microwave sensing technique cannot fully describe the microwave magnetic field strength distribution due to the signal detection method. Here, we propose an alternative Rabi resonance-based microwave imaging technique using a digital micromirror device and an alkali atomic cell. The experimental results well describe the distribution of the microwave field quantitatively and agree with the absorption imaging results. This technique can also be used as a method to analyze and measure the relaxation rate in an atomic vapor cell and offers a SI-traceable imaging approach for the microwave magnetic field. Its simple architecture holds great potential for the development of compact/miniature microwave field sensors.
Intramolecular vibrational redistribution in formic acid and its deuterated forms
Authors: Aerts Antoine , Brown Alex , Gatti Fabien
Published: June 2022

The intramolecular vibrational relaxation dynamics of formic acid and its deuterated isotopologues is simulated on the full-dimensional potential energy surface of Richter and Carbonnière [J. Chem. Phys. 148, 064303 (2018)] using the Heidelberg MCTDH package. We focus on couplings with the torsion vibrational modes close to the trans–cis isomerization coordinate from the dynamics of artificially excited vibrational mode overtones. The bright C–O stretch vibrational mode is coupled to the out-of-the plane torsion mode in HCOOH, where this coupling could be exploited for laser-induced trans-to-cis isomerization. Strong isotopic effects are observed: deuteration of the hydroxyl group, i.e., in HCOOD and DCOOD, destroys the C–O stretch to torsion mode coupling whereas in DCOOH, little to no effect is observed.
Disease and economic burden of infections in hospitalised children in New South Wales, Australia
Authors: McMullan Brendan J. , Valentine Jake C. , Hall Lisa , Thursky Karin
Published: June 2022

Objectives To describe the burden of disease and hospitalisation costs in children with common infections using statewide administrative data. Methods We analysed hospitalisation prevalence and costs for 10 infections: appendicitis, cellulitis, cervical lymphadenitis, meningitis, osteomyelitis, pneumonia, pyelonephritis, sepsis, septic arthritis, and urinary tract infections in children aged <18 years admitted to hospital within New South Wales, Australia, using an activity-based management administrative dataset over three financial years (1 July 2016–30 June 2019). Results Among 339 077 admissions, 28 748 (8.48%) were coded with one of the 10 infections, associated with a total hospitalisation cost of AUD230 905 190 and a per episode median length-of-stay of 3 bed-days. Pneumonia was the most prevalent coded infection (3.1% [n = 10 524] of all admissions), followed by appendicitis (1.61%; n = 5460), cellulitis (1.22%; n = 4126) and urinary tract infections (0.94%; n = 3193). Eighty per cent of children (n = 22 529) were admitted to a non-paediatric hospital. Mean costs were increased 1.18-fold per additional bed-day, 2.14-fold with paediatric hospital admissions, and 5.49-fold with intensive care unit admissions, which were both also associated with greater total bed-day occupancy. Indigenous children comprised 9.7% of children admitted with these infections, and mean per episode costs, and median bed-days were reduced compared with non-Indigenous children (0.84 [95% CI 0.78, 0.89] and 3 (IQR: 2,5) vs 2 (IQR: 2,4), respectively. Conclusions Infections in children requiring hospitalisation contribute a substantial burden of disease and cost to the community. This varies by infection, facility type, and patient demographics, and this information should be used to inform and prioritise programs to improve care for children.
Deadwood mass and microclimate affect labile soil carbon and nitrogen under thinning of a naturally regenerated oak forest
Authors: Kim Seongjun , Kim Hyun-Jun , Kim Choonsig , Lee Sang-Tae , Son Yowhan
Published: June 2022

Context Labile soil carbon and nitrogen are important indicators for evaluating carbon sequestration and nutrient availability under forest management such as thinning. Aims This study assessed the effects of thinning on labile soil carbon and nitrogen indices in a naturally regenerated oak forest. Methods Un-thinned control, 15% thinning, and 30% thinning were set up, and labile soil carbon and nitrogen (microbial biomass, permanganate oxidisable carbon, dissolved carbon and nitrogen, and inorganic nitrogen) and C:N balance indices (C:N ratio and threshold element ratio) were measured after 6 years. Key results Thinning generally increased labile soil carbon and nitrogen concentrations (P < 0.01); however, their fraction within the total soil carbon and nitrogen decreased under thinning. Redundancy analysis revealed that the remaining deadwood mass was the most influential factor affecting such differences in labile soil carbon and nitrogen indices across the three treatments (P < 0.01), although soil moisture had an effect as well (P < 0.05). Furthermore, the dissolved C:N ratio was higher than threshold element ratio only in 15% and 30% thinnings, indicating that thinning could shift the limiting factor for microbial growth from carbon to nitrogen by adding deadwoods, which provided carbon-rich substrates. Conclusions Overall, results demonstrate that deadwood retention and soil microclimatic changes could be the significant factors affecting soil carbon and nitrogen storage and the associated microbial affinity in thinned forests. Implications Therefore, sustainable forestry strategies for thinning residue management should be addressed to reinforce soil carbon and nitrogen conditions and the forest ecosystem functions.
Hepatitis E virus infects brain microvascular endothelial cells, crosses the blood–brain barrier, and invades the central nervous system
Authors: Tian Debin , Li Wen , Heffron C. Lynn , Wang Bo , Mahsoub Hassan M. , Sooryanarain Harini , Hassebroek Anna M. , Clark-Deener Sherrie , LeRoith Tanya , Meng Xiang-Jin
Published: June 2022

Hepatitis E virus (HEV) is an important but understudied zoonotic virus causing both acute and chronic viral hepatitis. A proportion of HEV-infected individuals also developed neurological diseases such as Guillain–Barré syndrome, neuralgic amyotrophy, encephalitis, and myelitis, although the mechanism remains unknown. In this study, by using an in vitro blood–brain barrier (BBB) model, we first investigated whether HEV can cross the BBB and whether the quasi-enveloped HEV virions are more permissible to the BBB than the nonenveloped virions. We found that both quasi-enveloped and nonenveloped HEVs can similarly cross the BBB and that addition of proinflammatory cytokine tumor necrosis factor alpha (TNF-α) has no significant effect on the ability of HEV to cross the BBB in vitro. To explore the possible mechanism of HEV entry across the BBB, we tested the susceptibility of human brain microvascular endothelial cells lining the BBB to HEV infection and showed that brain microvascular endothelial cells support productive HEV infection. To further confirm the in vitro observation, we conducted an experimental HEV infection study in pigs and showed that both quasi-enveloped and nonenveloped HEVs invade the central nervous system (CNS) in pigs, as HEV RNA was detected in the brain and spinal cord of infected pigs. The HEV-infected pigs with detectable viral RNA in CNS tissues had histological lesions in brain and spinal cord and significantly higher levels of proinflammatory cytokines TNF-α and interleukin 18 than the HEV-infected pigs without detectable viral RNA in CNS tissues. The findings suggest a potential mechanism of HEV-associated neuroinvasion.
Cicero, Academica 1.45
Authors: Snyder Charles
Published: June 2022

Focused on the reference to Socrates’ confession of ignorance at Academica 1.45, this paper
challenges the common assumption that the passage transmits Arcesilaus’ conception of Socrates. This paper develops in two steps
a more plausible reading of the passage. According to this reading, Cicero presents an interpretation of Arcesilaus’ historical
relation to Socrates. In conclusion, the paper argues that traditional readings of Acad. 1.45 underestimate not
only Cicero’s originality as an historical thinker, but also his clever reconstruction of Academic history, as it effectively
opposes the controversial Academic history defended by Antiochus in the early first century BCE.
Humanismus und Wahrheit
Authors: Law Esteban
Published: June 2022

This paper analyses the Verlagsanzeige of the humanist, mathematician, astronomer and publisher Johannes Regiomontanus (1436–1476). How is humanism expressed in this famous document from German early printing and what is its relationship to philosophy? The article shows that Regiomontanus advocated a special form of humanism that went beyond the standard humanism that he valued, with ‘truth’ as its most important aspect. From the epistemological perspective of the history of philosophy in Regiomontanus’s publishing programme, the ‘truth’ of mathematics is seen, analogous to some predecessors, as a paradigm of programmatic testimony. The integration of philosophy is evident in this, as in another specified way as well.
The derivative structure of Mandarin disyllabic verbs
Authors: Robson Shin Yong
Published: June 2022

With detailed examinations of the four characters that are known to be the most commonly used verb suffixes
(huà, dé/de, yú and yĭ) and their correlative implementations in Mandarin disyllabic verbs,
this article discusses the traits of the derivative structure that are formed with a content morpheme and a suffix. The
observations show that not all of the disyllabic words where these characters are the second morpheme are derivative verbs. On the
other hand, being the derivational components of the disyllabic verbs, these suffixes all have their individual qualities that
lead to their non-uniformed morphological representations.
Differences in the Delivery of Medications for Opioid use Disorder during Hospitalization by Racial Categories: A Retrospective Cohort Analysis;
Authors: Priest Kelsey C. , King Caroline A. , Englander Honora , Lovejoy Travis I. , McCarty Dennis
Published: June 2022

Background: As the drug-related overdose crisis and COVID-19 pandemic continue, communities need increased access to medications for opioid use disorder (MOUD) (i.e., buprenorphine and methadone). Disparities in the type of MOUD prescribed or administered by racial and ethnic categories are well described in the outpatient clinical environment. It is unknown, however, if these disparities persist when MOUD is provided in acute care hospitals. Methods: This study assessed differences in the delivery of buprenorphine versus methadone during acute medical or surgical hospitalizations for veterans with opioid use disorder (OUD) by racial categories (Black Non-Hispanic or Latino vs. White Non-Hispanic or Latino). Data were obtained retrospectively from the Veterans Health Administration (VHA) for federal fiscal year 2017. We built logistic regression models, adjusted for individual and hospital-related covariates, and calculated the predicted probabilities of MOUD delivery by racial categories. Results: The study cohort ( n = 1,313 unique patients; N = 107 VHA hospitals) had a mean age of 57 (range 23 to 87 years), was predominantly male (96%), and composed entirely of Black (29%) or White (71%) patients. White patients were 11% more likely than Black patients to receive buprenorphine than methadone during hospitalization ( p = 0.010; 95% CI: 2.7%, 20.0%). Among patients on MOUD prior to hospitalization, White patients were 21% more likely than Black patients to receive buprenorphine ( p = 0.000; 95% CI: 9.8%, 31.5%). Among patients newly initiated on MOUD during hospitalization, there were no differences by racial categories. Conclusion: We observed disparities in the delivery of buprenorphine versus methadone during hospitalization by racial categories. The observed differences in hospital-based MOUD delivery may be influenced by MOUD received prior to hospitalization within the racialized outpatient addiction treatment system. The VHA and health systems more broadly must address all aspects of racism that contribute to inequitable MOUD access throughout all clinical contexts.
Features of the primordial Universe in f(R)-gravity as viewed in the Jordan frame
Authors: Bamonti Nicola , Costantini Andrea , Montani Giovanni
Published: June 2022

We analyze some features of the primordial Universe as viewed in the Jordan frame formulation of the f(R)-gravity when the potential term is negligible. We start formulating the Hamiltonian picture using the three-metric determinant as a basic variable and we outline that its conjugated momentum appears linearly only in the scalar constraint. We construct the formalism to characterize the dynamics of a generic inhomogeneous cosmological model and specialize it to describe behaviors of the Bianchi Universes, both on a classical and a quantum regime. We demonstrate that, when the potential term of the additional scalar mode is negligible near to the initial singularity, the Bianchi IX cosmology is no longer affected by the chaotic behavior, typical in the vacuum of the Einsteinian dynamics. In fact, the presence of the Kasner stability region and its attractive character are properly characterized. Finally, we investigate the canonical quantization of the Bianchi I model, using as time variable the non-minimally coupled scalar field and showing that the existence of a conserved current is outlined for the corresponding Wheeler–DeWitt equation. The behavior of a localized wave-packet for the isotropic Universe is also evolved, demonstrating that the singularity is still present in this revised quantum dynamics.
Bright and dark Autler–Townes states in the atomic Rydberg multilevel spectroscopy
Authors: Bevilacqua Giuseppe , Arimondo Ennio
Published: June 2022

We investigated the Autler–Townes (AT) splitting produced by microwave (mw) transitions between atomic Rydberg states explored by optical spectroscopy from the ground electronic state. The laser-atom Hamiltonian describing the double irradiation of such a multilevel system is analysed on the basis of the Morris–Shore transformation. The application of this transformation to the mw-dressed atomic system allows the identification of bright, dark, and spectator states associated with different configurations of atomic states and mw polarisations. We derived synthetic spectra that show the main features of Rydberg spectroscopy. Complex AT spectra are obtained in a regime of strong mw dressing, where a hybridisation of the Rydberg fine structure states is produced by the driving.
The degradation of silicone rubber composites with ZnO microvaristors under impulse voltage
Authors: Huang Zhiwen , Yang Xiao , Yuan Zhikang , Sun Gang , Sun Ya , Hu Jun , He Jinliang
Published: June 2022

In this study, the degradation behavior of silicone rubber (SiR) composites with ZnO microvaristors under impulse voltage was investigated. Typical impulse voltages with different amplitudes were applied to the samples, and the degraded threshold electric field (E
b) and nonlinear coefficient (α) of the samples were obtained by conductivity test after every impulse was applied. Scanning electron microscope and energy dispersive spectroscopy were used to characterize the micro performance of the samples. The failure of the SiR composites was found to be attributed to the aging behavior in the microstructure of ZnO microvaristors, which was divided into four stages caused by the precipitation of Bi2O3 and the dissipation of the honeycomb grain-boundary structure. The mechanism of degradation was internal local heat accumulation and damage of the microelement caused by the thermal stress, generated by impulse voltage. This work is helpful to develop smart composite
materials with self-adaptive capability to control high electrical field and increase
the stability and durability of power apparatus and electronic devices.
Rotational and translational microrheology from shape-anisotropic particles
Authors: Arauz-Lara José Luis , Ramírez-Saíto Ángeles , Haro-Pérez Catalina
Published: June 2022

In this work, we report measurements of the mean squared angular and translational displacements of a colloidal dumbbell immersed in a viscoelastic fluid using digital microscopy. From the mean squared displacements, we obtain the mechanical properties of the media. Both angular and translational motions provide the same viscoelastic complex modulus and agree with that obtained from the translational motion of a spherical probe particle.