bluuebunny/crossref_metadata_2025 huggingface dataset:
Pregnancy in a Patient with Idiopathic Pulmonary Fibrosis: A Case Report
Authors: Horgan Rebecca , Kassem Zeinab , Too Gloria , Abuhamad Alfred , Warsof Steven
Published: January 2023

Idiopathic pulmonary fibrosis (IPF) is a progressive restrictive lung disease. Data on the impact of pregnancy on IPF and maternal outcome is extremely limited. We present the case of a 35-year-old woman, gravida 1 para 0 with familial IPF with no oxygen requirement prior to pregnancy. The patient demonstrated significant deterioration in her lung function beginning at 22 weeks' gestation and underwent hospitalization at 272/7 weeks gestation due to acute on chronic hypoxic respiratory failure, ultimately requiring delivery at 28 weeks' gestation. The patient has not regained her baseline pulmonary function and remains oxygen dependent at 5 months postpartum. Based on limited available data, significant maternal morbidity and mortality is reported for women with IPF who become pregnant.

Key Points
Low-cost telescope introduces infrared astronomy to the classroom
Authors: Thompson Avery
Published: January 2023

Infrared sensors provide an opportunity for introductory students to experience light outside the visible range.
Measuring gravity using cold atoms and quantum metrology
Authors: Ikenson Ben
Published: January 2023

A focus on frequency may enable smaller interferometers with greater precision
EXAFS investigation of strontium adsorption onto weathered biotite
Authors: Honda Mitsunori , Kaneta Yui , Yaita Tsuyoshi
Published: January 2023

The efficiency of the sorption of Sr2+ on weathered biotite (WB), a type of clay mineral, was investigated. Removal of Sr2+ and Cs+ is important in the treatment of contaminated water from the 1F accident, which is one of the radionuclide waste treatment problems. We focused on developing an adsorption method for Sr ions using WB, which is abundant in Fukushima. Applying a molten salt treatment, the amount of sorbed Sr2+ simply increased as the added mass ratio of strontium chloride (SrCl2) increased from 1:1, 1:5, and 1:10 for the onefold, fivefold, and tenfold additions of SrCl2, respectively. Then, the crystal structure of WB as an adsorbent was evaluated by x-ray diffraction (XRD) analysis. Thus, it was observed that the WB retained its original crystal structure even after the sorption of Sr2+. Extended x-ray absorption fine structure (EXAFS) analysis was performed to investigate the local sorption structure of Sr2+ in the WB. The results revealed that Sr2+ was preferentially sorbed into the SiO4 and Al2O3 layers when Sr2+ was in the low mass ratio, whereas it was mainly sorbed into the SiO4 layer when the ratio was high.
Reduction of motion axis by sensitivity calibration of sensor in shape measurement instrument using normal vector tracing
Authors: Miyawaki Takashi , Ikuchi Mikiya , Endo Katsuyoshi
Published: January 2023

High-precision free-form surface mirrors are required for synchrotron radiation facilities in the scientific field and semiconductor lithography systems in the industrial field. Previously, we developed a nano-profiler with the goal of achieving a measurement accuracy of 30 nm. The nano-profiler scanned and measured the slope angle of the surface to be measured with laser light and calculated the shape from the angle information. By driving the optical head and surface to be measured with four rotation axes and one translation axis, the surface could be scanned while keeping the optical path length constant. Although the rotation axis was controlled by a high-precision rotary encoder, pitching and yawing errors occurred in the translation axis. In this study, we attempt to eliminate the error of pitching and yawing from the conventional measurement operation of four axes of rotation and one axis of translation to the drive of only four axes of rotation. If the translation drive is eliminated, the optical path length will not be constant, and the sensitivity of the light-receiving element will change. Therefore, we propose a new method to calibrate the sensitivity of the receiving element and perform a comparative measurement with the conventional measurement method. Comparing the measured shapes obtained by both measurement results, it was found that the shapes had a maximum peak to valley difference of 6.2 nm. Thus, the proposed novel measurement method allows a significant reduction in pitching and yawing errors.
Purcell enhanced single-photon emission from a quantum dot coupled to a truncated Gaussian microcavity
Authors: Engel Lena , Kolatschek Sascha , Herzog Thomas , Vollmer Sergej , Jetter Michael , Portalupi Simone L. , Michler Peter
Published: January 2023

Purcell enhancement of quantum dot (QD) single-photon emission and increased device brightness have been demonstrated with various types of microcavities. Here, we present the first realization of a truncated Gaussian-shaped microcavity coupled to a QD. The implementation is based on wet-chemical etching and epitaxial semiconductor overgrowth. The cavity modes and their spatial profiles are experimentally studied and agree well with simulations. The fundamental mode wavelength with Q-factors around 6000 and a small polarization splitting of 29 μeV can be reproducibly controlled via fabrication design, enabling the adaption of the cavity to a specific QD. Finally, transitions of a QD inside a cavity are tuned on and off resonance via temperature tuning. A reduced decay time by a factor above 3 on resonance clearly indicates Purcell enhancement while second-order correlation measurements of g(2)(0) = 0.057 prove that the QDs single-photon characteristic is preserved.
Ionization dynamics and damage conditions in fused silica irradiated with mid-infrared femtosecond pulses
Authors: Tsibidis George D. , Stratakis Emmanuel
Published: January 2023

The employment of ultrashort laser sources at the mid-infrared (mid-IR) spectral region for dielectrics is expected to open innovative routes for laser patterning and a wealth of exciting applications in optics and photonics. To elucidate the material response to irradiation with mid-IR laser sources, a consistent analysis of the interaction of long wavelength femtosecond pulses with dielectric materials is presented. The influence of the pulse duration is particularly emphasized in specifying the laser parameters for which photoionization and impact ionization are important. Simulation results using pulses at 2.2, 3.2, and 5 μm are conducted to illustrate optimum conditions for the onset of damage on the solid that is related to the occurrence of the optical breakdown. The results predict that the damage threshold scales as ∼τpa (0.31≤a≤0.37) at all laser wavelengths. Given the significant effect of the induced excitation level on excitation of surface plasmons (SPs), which account for the formation of laser-induced periodic structures oriented perpendicular to the laser polarization, a correlation of the produced electron densities with SPs and the threshold of SP excitation (∼τpβ, 0.33≤β≤0.39) are also discussed in this as yet unexplored spectral region. The results are expected to guide development of an innovative approach to surface patterning using strong mid-IR pulses for advanced applications.
Generation of spin-polarized electronic currents using perpendicularly magnetized cobalt ferrite spin-filtering barriers grown on spinel-type-conductive layers
Authors: Tanaka Masaaki , Furuta Motoharu , Ichikawa Tomoyuki , Morishita Masaya , Hung Yu-Min , Honda Syuta , Ono Teruo , Mibu Ko
Published: January 2023

We demonstrated the generation of perpendicularly spin-polarized electronic currents using a tunnel spin-filtering effect through insulative Fe-rich cobalt ferrite CoxFe3−xO4+δ (I-CFO) barriers with perpendicular magnetic anisotropy (PMA). The I-CFO films grown on conductive Fe-rich cobalt ferrite CoyFe3−yO4 (C-CFO) films, which were deposited on additional I-CFO buffer layers on MgO(001) substrates, exhibited PMA induced by an epitaxial strain. Magnetic tunnel junctions (MTJs), which comprise C-CFO electrode layers, I-CFO barrier layers, and perpendicularly magnetized Co/{Tb/Co}15/Co spin detection layers, showed a tunnel magnetoresistance (TMR) effect. This indicated that spin-polarized tunnel currents were injected into the spin detection layers. A spin injection efficiency of −28% was observed for the MTJs with an I-CFO barrier of 3.0 nm in thickness at 100 K. The voltage dependence of the TMR effect indicates that the spin-injection efficiency is affected by voltage-dependent changes in the effective spin-dependent barrier width. The combination of spinel-type C-CFO and I-CFO films with well-controlled compositions and lattice strains is, therefore, applicable as a spin-injection source for spintronics devices when perpendicularly spin-polarized electronic currents are required.
Machine learning assisted coarse-grained molecular dynamics modeling of meso-scale interfacial fluids
Authors: Ge Pei , Zhang Linfeng , Lei Huan
Published: January 2023

A hallmark of meso-scale interfacial fluids is the multi-faceted, scale-dependent interfacial energy, which often manifests different characteristics across the molecular and continuum scale. The multi-scale nature imposes a challenge to construct reliable coarse-grained (CG) models, where the CG potential function needs to faithfully encode the many-body interactions arising from the unresolved atomistic interactions and account for the heterogeneous density distributions across the interface. We construct the CG models of both single- and two-component polymeric fluid systems based on the recently developed deep coarse-grained potential [Zhang et al., J. Chem. Phys. 149, 034101 (2018)] scheme, where each polymer molecule is modeled as a CG particle. By only using the training samples of the instantaneous force under the thermal equilibrium state, the constructed CG models can accurately reproduce both the probability density function of the void formation in bulk and the spectrum of the capillary wave across the fluid interface. More importantly, the CG models accurately predict the volume-to-area scaling transition for the apolar solvation energy, illustrating the effectiveness to probe the meso-scale collective behaviors encoded with molecular-level fidelity.
Suppression of laser beam’s polarization and intensity fluctuation via a Mach–Zehnder interferometer with proper feedback
Authors: Hou Xiaokai , Liu Shuo , Wang Xin , Lu Feifei , He Jun , Wang Junmin
Published: January 2023

Long ground-Rydberg coherence lifetime is interesting for implementing high-fidelity quantum logic gates, many-body physics, and other quantum information protocols. However, the potential well formed by a conventional far-off-resonance red-detuned optical-dipole trap that is attractive for ground-state cold atoms is usually repulsive for Rydberg atoms, which will result in the rapid loss of atoms and low repetition rate of the experimental sequence. Moreover, the coherence time will be sharply shortened due to the residual thermal motion of cold atoms. These issues can be addressed by a one-dimensional magic lattice trap, which can form a deeper potential trap than the traveling wave optical dipole trap when the output power is limited. In addition, these common techniques for atomic confinement generally have certain requirements for the polarization and intensity stability of the laser. Here, we demonstrated a method to suppress both the polarization drift and power fluctuation only based on the phase management of the Mach–Zehnder interferometer for a one-dimensional magic lattice trap. With the combination of three wave plates and the interferometer, we used the instrument to collect data in the time domain, analyzed the fluctuation of laser intensity, and calculated the noise power spectral density. We found that the total intensity fluctuation comprising laser power fluctuation and polarization drift was significantly suppressed, and the noise power spectral density after closed-loop locking with a typical bandwidth of 1–3000 Hz was significantly lower than that under the free running of the laser system. Typically, at 1000 Hz, the noise power spectral density after locking was about 10 dB lower than that under the free running of a master oscillator power amplifier system. The intensity–polarization control technique provides potential applications for atomic confinement protocols that demand fixed polarization and intensity.
Tutorial: Lead sulfide colloidal quantum dot infrared photodetector
Authors: Wu Haobo , Ning Zhijun
Published: January 2023

Lead sulfide (PbS) colloidal quantum dots (CQDs) is emerging as a promising material for infrared photodetectors because of its strong absorbance in the near infrared region, the tunable energy gap, facile fabrication, and excellent electrical properties. This Tutorial gives a comprehensive introduction of materials and devices of PbS CQD based infrared photodetectors. First, we introduce the concept of CQDs and the typical characters of CQDs. The synthesis of PbS CQDs and a solid film fabrication method are then summarized. Subsequently, the study for defect passivation and carrier transport in a PbS CQD thin film is presented. In the end, the device structure, the electrical diagram, and strategies for enhancing device performance of three kinds of infrared photodetector are concluded.
Fluorine-regulated cathode electrolyte interphase enables high-energy quasi-solid-state lithium metal batteries
Authors: Hou Wangshu , Zhai Yanfang , Chen Zongyuan , Liu Chengyong , Ouyang Chuying , Hu Ning , Liang Xiao , Paoprasert Peerasak , Song Shufeng
Published: January 2023

Lithium metal batteries (LMBs) enabled by quasi-solid electrolytes are under consideration for their prospect of reliable safety and high energy density. The limited oxidative stabilization and inferior chemical compatibility of quasi-solid electrolytes toward high-voltage cathodes are a long-standing challenge. Herein, we report that an additive level (0.05 M) of LiPF6 is introduced to a polymeric concentrated quasi-solid electrolyte (10 M LiFSI in poly-1,3-dioxolane [poly-DOL], ethylene carbonate [EC], and ethyl methyl carbonate [EMC]) to build in situ a fluorine-regulated cathode electrolyte interphase (CEI) on a highly catalytic LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode. The CEI with a conformal thickness of ∼7 nm features a fluorine-rich outer layer and manipulative LiF/organofluorine species, which mitigates the detrimental side reactions between the quasi-solid electrolyte and NCM cathode and maintains the structure of cycled NCM, as demonstrated by the characterizations of SEM, TEM, XRD, Raman spectroscopy, AFM, EDS, and XPS. As a result, the LiPF6-contained polymeric concentrated quasi-solid electrolyte not only provides a superior ionic conductivity of 3.1 × 10−4 S cm−1 at 25 °C and a remarkable electrochemical stability window of 5.5 V vs Li/Li+, but also achieves an excellent capacity retention of 74% after 100 cycles for LiǁNCM811 quasi-solid-state LMB, bringing a quasi-solid electrolyte design strategy of engineered CEI chemistry for LMBs.
The effect of nutation angle on the flow inside a precessing cylinder and its dynamo action
Authors: Kumar Vivaswat , Pizzi Federico , Giesecke André , Šimkanin Ján , Gundrum Thomas , Ratajczak Matthias , Stefani Frank
Published: January 2023

The effect of the nutation angle on the flow inside a precessing cylinder is experimentally explored and compared with numerical simulations. The focus is laid on the typical breakdown of the directly forced m = 1 Kelvin mode for increasing precession ratio (Poincaré number) and the accompanying transition between laminar and turbulent flows. Compared to the reference case with a 90° nutation angle, prograde rotation leads to an earlier breakdown, while in the retrograde case, the forced mode continues to exist also for higher Poincaré numbers. Depending largely on the occurrence and intensity of an axisymmetric double-roll mode, a kinematic dynamo study reveals a sensitive dependence of the self-excitation condition on the nutation angle and the Poincaré number. Optimal dynamo conditions are found for 90° angle which, however, might shift to slightly retrograde precession for higher Reynolds numbers.
Numerical investigation of two-dimensional axisymmetric and three-dimensional flow simulations over a benchmark underwater vehicle
Authors: Rahul Krishna H. , Issac Manoj T. , Ebenezer D. D.
Published: January 2023

Two-dimensional (2D) axisymmetric simulation is an efficient and time-saving computational fluid dynamics (CFD) technique when the body is axisymmetric, and the flow is along the length of the body. In the present paper, this technique is used to investigate turbulent flow around the bare hull configuration of the Defense Advanced Research Project Agency submarine model. Verification and validation of the results are done at three levels. The values of the total resistance, the distribution of the wall shear stress and the pressure on the surface, and the velocity profiles at various distances from the nose are compared with results obtained by using three-dimensional (3D) simulations and experimental results from the literature. The uncertainty in CFD results due to meshing is reported using Richardson Extrapolation. It is shown that the errors are minor, and the savings in computer memory and computation time are tremendous using 2D axisymmetric simulations. Good CFD practices essential for 2D axisymmetric simulations are also presented in this article, which will be helpful for the CFD community to conduct numerical investigations on any other axisymmetric bare hull bodies, such as torpedoes, missiles, submarines, and autonomous underwater vehicles in the future. Finally, the components of drag, coefficient of pressure, and wall shear stress at the highest speed (9.26 m/s) are also obtained using 2D axisymmetric simulation, which has not been previously reported in any other literature. The level of rigor in the 2D axisymmetric simulation reported here is rarely seen in recent literature.
Simulation of two-dimensional infrared Raman spectroscopy with application to proteins
Authors: van Hengel Carleen D. N. , van Adrichem Kim E. , Jansen Thomas L. C.
Published: January 2023

Two-dimensional infrared Raman spectroscopy is a powerful technique for studying the structure and interaction in molecular and biological systems. Here, we present a new implementation of the simulation of the two-dimensional infrared Raman signals. The implementation builds on the numerical integration of the Schrödinger equation approach. It combines the prediction of dynamics from molecular dynamics with a map-based approach for obtaining Hamiltonian trajectories and response function calculations. The new implementation is tested on the amide-I region for two proteins, where one is dominated by α-helices and the other by β-sheets. We find that the predicted spectra agree well with experimental observations. We further find that the two-dimensional infrared Raman spectra at least of the studied proteins are much less sensitive to the laser polarization used compared to conventional two-dimensional infrared experiments. The present implementation and findings pave the way for future applications for the interpretation of two-dimensional infrared Raman spectra.
Stable dingo population structure and purity over 11 years of lethal management
Authors: Stephens Danielle , Kennedy Malcolm S. , Kreplins Tracey L.
Published: January 2023

Context Interaction between predators and humans is a key driver of human–wildlife conflicts, and can underpin management of predator populations. Management of the impacts of dingoes on livestock and native species is a prime example of a persistent and contentious predator management issue with potential impacts on the integrity of dingo populations. To manage the potential impacts of dingoes and their control, it is imperative to understand the effects of control approaches on their populations in the short and long term. Hybridisation of dingoes with domestic dogs also threatens the genetic integrity of pure dingoes. It has been hypothesised that lethal control of dingoes can facilitate hybridisation through disrupting pack social structures leading to increased dingo–domestic dog interactions. Aims We aimed to to investigate how dingo population structure and genetic purity have changed, assessing dingo purity, individual relatedness, population clustering and gene flow, particularly across land use types and barrier fences, in the context of ongoing lethal control within the Murchison Regional Vermin Cell area in Western Australia (WA). Methods We tested dingo genetic samples from three distinct sampling periods (2009, 2014 and 2020) for changes in population summary statistics and dingo ancestry. Barriers and corridors to gene flow were also examined. Key results We identified three genetically distinct populations in the study area, consistent with previous genetic studies in WA. We did not find any evidence of change in dingo purity or population characteristics; however, barrier fencing may be influencing recent gene flow. Conclusions The metapopulation of dingoes in the southern rangelands of WA appears to be stable over the 11 years assessed. Implications Because we were unable to demonstrate that lethal control has accelerated hybridisation between dingoes and domestic dogs in the study area over the last 11 years, we have no evidence that lethal control to reduce losses to livestock production and for conservation of native wildlife in the southern rangelands of WA is putting dingo purity at risk. Fencing appears to be an effective management tool because there is some evidence it is congruent with reduced gene flow in areas where the fences are well maintained.
Recovery of a marine keystone predator transforms terrestrial predator–prey dynamics
Authors: Roffler Gretchen H. , Eriksson Charlotte E. , Allen Jennifer M. , Levi Taal
Published: January 2023

Sea otters (Enhydra lutris) and wolves (Canis lupus) are two apex predators with strong and cascading effects on ecosystem structure and function. After decades of recovery from near extirpation, their ranges now overlap, allowing sea otters and wolves to interact for the first time in the scientific record. We intensively studied wolves during 2015 to 2021 in an island system colonized by sea otters in the 2000s and by wolves in 2013. After wolf colonization, we quantified shifts in foraging behavior with DNA metabarcoding of 689 wolf scats and stable isotope analyses, both revealing a dietary switch from Sitka black-tailed deer (Odocoileus hemionus), the terrestrial in situ primary prey, to sea otters. Here we show an unexpected result of the reintroduction and restoration of sea otters, which became an abundant marine subsidy for wolves following population recovery. The availability of sea otters allowed wolves to persist and continue to reproduce, subsequently nearly eliminating deer. Genotypes from 390 wolf scats and telemetry data from 13 wolves confirmed island fidelity constituting one of the highest known wolf population densities and upending standardly accepted wolf density predictions based on ungulate abundance. Whereas marine subsidies in other systems are generally derived from lower trophic levels, here an apex nearshore predator became a key prey species and linked nearshore and terrestrial food webs in a recently deglaciated and rapidly changing ecosystem. These results underscore that species restoration may serve as an unanticipated nutrient pathway for recipient ecosystems even resulting in cross-boundary subsidy cascades.
Genome editing in plants using the compact editor CasΦ
Authors: Li Zheng , Zhong Zhenhui , Wu Zhongshou , Pausch Patrick , Al-Shayeb Basem , Amerasekera Jasmine , Doudna Jennifer A. , Jacobsen Steven E.
Published: January 2023

Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) systems have been developed as important tools for plant genome engineering. Here, we demonstrate that the hypercompact CasΦ nuclease is able to generate stably inherited gene edits in
Arabidopsis
, and that CasΦ guide RNAs can be expressed with either the Pol-III U6 promoter or a Pol-II promoter together with ribozyme mediated RNA processing. Using the
Arabidopsis fwa
epiallele, we show that CasΦ displays higher editing efficiency when the target locus is not DNA methylated, suggesting that CasΦ is sensitive to chromatin environment. Importantly, two CasΦ protein variants, vCasΦ and nCasΦ, both showed much higher editing efficiency relative to the wild-type CasΦ enzyme. Consistently, vCasΦ and nCasΦ yielded offspring plants with inherited edits at much higher rates compared to WTCasΦ. Extensive genomic analysis of gene edited plants showed no off-target editing, suggesting that CasΦ is highly specific. The hypercompact size, T-rich minimal protospacer adjacent motif (PAM), and wide range of working temperatures make CasΦ an excellent supplement to existing plant genome editing systems.
Micropolíticas lingüísticas familiares de resistencia
Authors: Nandi Anik
Published: January 2023

Cada individuo, independientemente de su edad, tiene prácticas lingüísticas propias en el seno familiar y, además, unas creencias sobre la elección de la lengua o lenguas en una sociedad multilingüe. Las prácticas lingüísticas en el ámbito familiar son sumamente importantes para entender la transmisión intergeneracional de un idioma minoritario. Partiendo de datos etnográficos, en este trabajo se analizan notas de campo y observación, entrevistas semiestructuradas individuales a progenitores y dos grupos de discusión formados por cuatro familias cada uno, con el objetivo de investigar las estrategias parentales para la transmisión intergeneracional del gallego en los hábitats urbanos y periurbanos de Galicia, donde el castellano es el principal idioma de socialización. El artículo pretende aportar conocimiento sobre la agencia de los progenitores pro gallego que, a través de sus creencias, gestión y prácticas lingüísticas individuales, juegan un papel significativo en la revitalización y mantenimiento del gallego fuera de la escuela, concretamente en el ámbito doméstico.
STAT3 regulates CD8+ T cell differentiation and functions in cancer and acute infection
Authors: Sun Qinli , Zhao Xiaohong , Li Ruifeng , Liu Dingfeng , Pan Birui , Xie Bowen , Chi Xinxin , Cai Dongli , Wei Peng , Xu Wei , Wei Kun , Zhao Zixuan , Fu Yujie , Ni Ling , Dong Chen
Published: January 2023

In cancer, persistent antigens drive CD8+ T cell differentiation into exhausted progenitor (Texprog) and terminally exhausted (Texterm) cells. However, how the extrinsic and intrinsic regulatory mechanisms cooperate during this process still remains not well understood. Here, we found that STAT3 signaling plays essential roles in promoting intratumor Texterm cell development by enhancing their effector functions and survival, which results in better tumor control. In tumor microenvironments, STAT3 is predominantly activated by IL-10 and IL-21, but not IL-6. Besides, STAT3 also plays critical roles in the development and function of terminally differentiated effector CD8+ T cells in acute infection. Mechanistically, STAT3 transcriptionally promotes the expression of effector function-related genes, while it suppresses those expressed by the progenitor Tex subset. Moreover, STAT3 functions in collaboration with BATF and IRF4 to mediate chromatin activation at the effector gene loci. Thus, we have elucidated the roles of STAT3 signaling in terminally differentiated CD8+ T cell development, especially in cancer, which benefits the development of more effective immunotherapies against tumors.
A mathematical framework for nonlinear wavefront reconstruction in adaptive optics systems with Fourier-type wavefront sensing
Authors: Hutterer Victoria , Neubauer Andreas , Shatokhina Julia
Published: January 2023

Advanced adaptive optics (AO) instruments have applications in ophthalmic imaging, free-space optical communications and the future generation of extremely large telescopes. These AO systems are designed to perform real-time corrections of dynamic wavefront aberrations. The corrections can be performed by converting wavefront measurements into deformable mirror (DM) actuator commands. The role of the DM is to mitigate aberrations by restoring a planar wavefront. Optimal DM actuator commands therefore require precise phase measurements across the entire wavefront. Reconstructing a wavefront from wavefront sensor (WFS) data is an inverse problem that depends on the type of WFS implemented. Nonlinear Fourier-type WFSs are included in the design of many current and upcoming AO systems. Conventionally, these sensors perform AO control based on simplifications and linearisations of the underlying models. However, in nonlinear regimes, approximation errors critically degrade image quality. This study looks at overcoming nonlinear wavefront sensing regimes by introducing a nonlinear, iterative algorithm for Fourier-type wavefront reconstruction. The algorithm used is well-known in the field of inverse problems. The underlying mathematical theory for modelling Fourier-type WFSs is provided, along with how these models can be used to perform nonlinear wavefront reconstruction. A significant advantage of the analysis presented is its generalised applicability to any Fourier-type sensor. The only input required is the mathematical expression for the optical element transfer function. The generalised and full mathematical model of Fourier-type WFSs is introduced in a Sobolev space setting. Necessary inputs are derived for the nonlinear iterative algorithms, such as Fréchet derivatives and adjoints. The generalised theory is then expanded to solve the inverse problem of wavefront reconstruction for all Fourier-type WFSs. Moreover, the study concentrates on the pyramid WFS (PWFS)—one of the most well-known Fourier-type WFSs—and shows a Hilbert transform representation of the amplitude of the incoming light on its detector. The developed theory is demonstrated using a simulated PWFS to measure an example wavefront.
Analysis of ionization characteristics during single discharge of microcathode arc thruster
Authors: Ji Tianyuan , Wei Liqiu , Wang Lu , Li Ji , Zhao Yongguo , Li Tingwan , Liang Tiance , Li Hong , Zhu Ximing , Ding Yongjie
Published: January 2023

In this investigation, to monitor the cathodic ionization process of the microcathodic arc thruster, electrical detection was combined with enhanced ICCD spectroscopic detection to diagnose the cathodic ionization characteristics of microcathode arc thrusters with 1 μs time resolution for examining the microsecond-level discharge process. After we used the titanium ion spectroscopy model to calculate the ion density distribution during the cathode ionization of the microcathode arc thruster, we found that the microcathode arc thruster showed a double peak of titanium ions in one cycle. This phenomenon may be related to the combined effect of arc heat transfer and ion current impact on the cathode during the discharge of the microcathode arc thruster. The results showed that changes in the input energy of the power processing unit can effectively affect the temporal relationship between arc power peak and arc current peak, which in turn affects the ionization of the cathode of the microcathode arc thruster.
Perpendicular antiferromagnetic ordering and canted spins in van der Waals FePS3 probed by spin Hall magnetoresistance
Authors: Hui Yajuan , Lu Jun , Jiang Hui , Lin Weinan , Dong Chao , Dong Kaifeng , He Qiang , Miao Xiangshui
Published: January 2023

Van der Waals antiferromagnets (AFMs) provide a two-dimensional (2D) platform for spintronic devices with exceptional properties. However, the electric transport features of the magnetic order of van der Waals AFM influenced by different field directions and amplitudes has not been demonstrated systematically. In this letter, we investigate the magnetic texture of the exfoliated van der Waals FePS3, a uniaxial AFM with perpendicular anisotropy, detected by the spin Hall magnetoresistance (SMR). Magnetic field- and temperature- dependent longitudinal magnetoresistance measurements in three orthogonal directions for the exfoliated FePS3/Pt nanostructures are conducted. The modulations in the SMR signal enable the separation of two contributions to the SMR, one of which corresponds to the negative signature of AFM SMR caused by in-plane field rotations, and the other of which is caused by canted spins in perpendicular AFM order. Our findings offer great guidance for further research and investigation using SMR approach of the magnetic texture in van der Waals AFMs.
Chiral photocurrent in a Quasi-1D TiS3 (001) phototransistor
Authors: Gilbert Simeon J , Li Mingxing , Chen Jia-Shiang , Yi Hemian , Lipatov Alexey , Avila Jose , Sinitskii Alexander , Asensio Maria C , Dowben Peter A , Yost Andrew J
Published: January 2023

The presence of in-plane chiral effects, hence spin–orbit coupling, is evident in the changes in the photocurrent produced in a TiS3(001) field-effect phototransistor with left versus right circularly polarized light. The direction of the photocurrent is protected by the presence of strong spin–orbit coupling and the anisotropy of the band structure as indicated in NanoARPES measurements. Dark electronic transport measurements indicate that TiS3 is n-type and has an electron mobility in the range of 1–6 cm2V−1s−1. I–V measurements under laser illumination indicate the photocurrent exhibits a bias directionality dependence, reminiscent of bipolar spin diode behavior. Because the TiS3 contains no heavy elements, the presence of spin–orbit coupling must be attributed to the observed loss of inversion symmetry at the TiS3(001) surface.
Curvature-induced stabilization and field-driven dynamics of magnetic hopfions in toroidal nanorings
Authors: Corona R M , Saavedra E , Castillo-Sepulveda S , Escrig J , Altbir D , Carvalho-Santos V L
Published: January 2023

Three dimensional magnetic textures are a cornerstone in magnetism research. In this work, we analyze the stabilization and dynamic response of a magnetic hopfion hosted in a toroidal nanoring with intrinsic Dzyaloshinskii–Moriya interaction simulating FeGe. Our results evidence that unlike their planar counterparts, where perpendicular magnetic anisotropies are necessary to stabilize hopfions, the shape anisotropy originated on the torus symmetry naturally yields the nucleation of these topological textures. We also analyze the magnetization dynamical response by applying a magnetic field pulse to differentiate among several magnetic patterns. Finally, to understand the nature of spin wave modes, we analyze the spatial distributions of the resonant mode amplitudes and phases and describe the differences among bulk and surface modes. Importantly, hopfions lying in toroidal nanorings present a non-circularly symmetric poloidal resonant mode, which is not observed in other systems hosting hopfions.
Solvability and pullback attractor for a class of differential hemivariational inequalities with its applications
Authors: Li Xiuwen , Liu Zhenhai , Papageorgiou Nikolaos S
Published: January 2023

In this paper, we consider an abstract system which consists of a nonlinear differential inclusion and a parabolic hemivariational inequality (DPHVI) in Banach spaces. The objective of this paper is four fold. The first target is to deal with the existence of solutions and the properties which involve the boundedness and continuous dependence results of the solution set to parabolic hemivariational inequality. The second aim is to investigate the existence of mild solutions to DPHVI by means of a fixed point technique. The third one is to study the existence of a pullback attractor for the multivalued processes governed by DPHVI. Finally, the fourth goal is to demonstrate a concrete application of our main results arising from the dynamic thermoviscoelasticity problems.
Vibration acoustic modulation for bolt looseness monitoring based on frequency-swept excitation and bispectrum
Authors: Zhao Nan , Linsheng Huo , Song Gangbing
Published: January 2023

The monitoring of bolt looseness is crucial to ensure the safety and reliability of structures. Prior studies have demonstrated that the vibro-acoustic modulation (VAM) method based on the nonlinear ultrasonic theory is sensitive to the early looseness of bolted connections. However, one limitation of the traditional VAM method is that the low frequency (LF) and high frequency (HF) for excitation should be specified in advance. The resonant frequency of the bolted structures changes after loosening, leading to inaccuracies in monitoring results if pre-specified excitation frequencies are used and not adapted to the new situation. To address this limitation, this paper improves the VAM method by using swept sine signals for both LF and HF excitations and relying on the bispectrum energy of the measured response to indicate the bolt pre-load. A steel bolted connection was fabricated and loaded on a universal testing machine to simulate different bolt pre-loads. Three low-cost lead zirconate titanate patches served as the LF actuator, HF actuator and sensor in the experiment. The experimental results demonstrate that the improved VAM method can evaluate the bolt looseness with better efficiency and robustness than the traditional VAM methods which use fixed frequencies as excitations. Therefore, the proposed method in this paper can potentially monitor the damages in complex structures based on nonlinear ultrasound theory.
On the limiting rate of generation of random sequences and the principle of particle identity
Authors: Molotkov S N
Published: January 2023

Estimates for the limiting rate of generation of random sequences in random number generators dictated by fundamental prohibitions of Nature are obtained. The relationship between the limiting rate of the generation of random sequences and the principle of particle identity is established.
Studies in pulse shape discrimination for an optimized ASIC design
Authors: Boxer B. , Godfrey B. , Grace C. , Johnson J. , Khandwala R. , Tripathi M.
Published: January 2023

The continued advancements of Silicon Photomultipliers (SiPMs) have made them viable photosensors for low recoil energy Pulse Shape Discrimination (PSD) between fast neutron and gamma interactions when coupled to an appropriate scintillator. At the same time, the large number of channels in a typical array calls for the development of low-cost and low-power electronics. A custom integrated circuit (ASIC) is an ideal solution for this purpose. To assess the requirements for such an ASIC, studies were performed using two scintillators, Stilbene and EJ-276, coupled to a 6 × 6 mm SiPM from Onsemi. We demonstrate that both scintillators are viable for performing PSD for interaction energies from 100 keV to several MeV while optimizing the integration periods used in the PSD metric. These measurements inform the design parameters of the ASIC under development.
n/γ discrimination for CLYC detector using a one-dimensional Convolutional Neural Network
Authors: Zhao Keqing , Feng Changqing , Wang Shuwen , Shen Zhongtao , Zhang Kan , Liu Shubin
Published: January 2023

In this work, a one-dimensional convolutional neural network
(1D-CNN) is used for performing pulse shape discrimination (PSD)
between the neutrons and gamma rays detected by the
Cs2LiYCl6: Ce3+(CLYC) crystal. We use three different
optimizers to train the CNN for comparing the effects of different
optimizers on the training results. The neural network that uses the
RMSProp optimizer performed the best. The accuracy of the AmBe
source reaches 99.395%, and the false alarm rates (FARs) of the
gamma source, i.e., 137Cs and 22Na are only 0.003% and
0.020%, separately. By the same dataset, we introduced several
other methods to compare, including the classic charge integral
(CI), partial charge-to-peak ratio (PCPR), decision tree (DT),
support vector machine (SVM), K-nearest neighbor (KNN), and
artificial neural network (ANN). Among these introduced methods, the
FARs of the ANN method are better, which are 0.004% and 0.031%;
however, its error is higher than that of the CNN method. A detailed
discussion of the discrimination capability as a function of the
sampling rate of the digitizer is also presented. We compare the
performance of the CNN method and the traditional integral method
under different sampling rates. The results show that even under a
low sampling rate, the discrimination of the CNN method is almost
unchanged, while the accuracy of the traditional integral method
deteriorates rapidly. In addition, the CNN method is used for
classifying more complicated particles, neutrons, gamma-rays, noise,
and pile-up waveforms. The classification results show that the CNN
has the ability to separate the four signals from the dataset
efficiently.
A method for portable PPG signal dynamic acquisition and denoise based on CEEMDAN and wavelet transform
Authors: Tian Ziwei , Jia Yunfang
Published: January 2023

Photoplethysmography (PPG) is a non-invasive technology and widely used in medical monitoring. Nowadays, dynamic vital signs monitoring based on PPG technology is in emergence and shows great potential for commercialization, however, it is still challenged by massive noise evoked by respiration and muscle contraction. Herein, a portable PPG signal's dynamic acquisition and denoise system is constructed and applied to blood pressure (BP) estimation, in which an improved PPG denoise method based on complete ensemble empirical mode decomposition with adaptive noise and wavelet transform (CEEMDAN-WT), is described. Firstly, original PPG signal is measured by the proposed hardware, then CEEMDAN decomposes it into a group of components. Secondly, the noise dominated components are found by calculating the coefficients between the components and original signal, and removed by WT. Thirdly, fast Fourier transform is performed to remove the component whose dominant frequency exceeds 0.5–20 Hz. Fourthly, a fresh PPG signal is reconstructed and compared with the signal rebuilt by other methods, which proves that CEEMDAN-WT has higher signal-to-noise ratio and lower root mean square error. Last but not least, the reconstructed signal is applied to estimate systolic and diastolic BP, according to Windkessel model and aided by neural network algorithm. Overall, this work demonstrates the feasibility of the portable PPG dynamic acquisition and its application for dynamic vital signs monitoring, in which CEEMDAN-WT algorithm can effectively remove most of the noises in dynamic PPG signal. In conclusion, it demonstrates CEEMDAN-WT method can effectively remove noise from PPG signals in the state of motion, it may have a good potential for calculating other physiological indexes besides BP, and push PPG applications from professional medical to daily life.
Prediction errors for penalized regressions based on generalized approximate message passing
Authors: Sakata Ayaka
Published: January 2023

We discuss the prediction accuracy of assumed statistical models in terms of prediction errors for the generalized linear model and penalized maximum likelihood methods. We derive the forms of estimators for the prediction errors, such asCpcriterion, information criteria, and leave-one-out cross validation (LOOCV) error, using the generalized approximate message passing (GAMP) algorithm and replica method. These estimators coincide with each other when the number of model parameters is sufficiently small; however, there is a discrepancy between them in particular in the parameter region where the number of model parameters is larger than the data dimension. In this paper, we review the prediction errors and corresponding estimators, and discuss their differences. In the framework of GAMP, we show that the information criteria can be expressed by using the variance of the estimates. Further, we demonstrate how to approach LOOCV error from the information criteria by utilizing the expression provided by GAMP.
Multicontact formulation for non-conservative field theories
Authors: de León Manuel , Gaset Jordi , Muñoz-Lecanda Miguel C , Rivas Xavier , Román-Roy Narciso
Published: January 2023

A new geometric structure inspired by multisymplectic and contact geometries, which we call multicontact structure, is developed to describe non-conservative classical field theories. Using the differential forms that define this multicontact structure as well as other geometric elements that are derived from them while assuming certain conditions, we can introduce, on the multicontact manifolds, the variational field equations which are stated using sections, multivector fields, and Ehresmann connections on the adequate fiber bundles. Furthermore, it is shown how this multicontact framework can be adapted to the jet bundle description of classical field theories; the field equations are stated in the Lagrangian and the Hamiltonian formalisms both in the regular and the singular cases.
Algebraic (super-)integrability from commutants of subalgebras in universal enveloping algebras
Authors: Campoamor-Stursberg Rutwig , Latini Danilo , Marquette Ian , Zhang Yao-Zhong
Published: January 2023

Starting from a purely algebraic procedure based on the commutant of a subalgebra in the universal enveloping algebra of a given Lie algebra, the notion of algebraic Hamiltonians and the constants of the motion generating a polynomial symmetry algebra is proposed. The case of the special linear Lie algebra

s
l

(
n
)

is discussed in detail, where an explicit basis for the commutant with respect to the Cartan subalgebra is obtained, and the order of the polynomial algebra is computed. It is further shown that, with an appropriate realization of

s
l

(
n
)

, this provides an explicit connection with the generic superintegrable model on the

(
n
−
1
)

-dimensional sphere

S

n
−
1

and the related Racah algebra R(n). In particular, we show explicitly how the models on the two-sphere and three-sphere and the associated symmetry algebras can be obtained from the quadratic and cubic polynomial algebras generated by the commutants defined in the enveloping algebra of

s
l

(
3
)

and

s
l

(
4
)

, respectively. The construction is performed in the classical (or Poisson-Lie) context, where the Berezin bracket replaces the commutator.
Case study: Ground Improvement technique with Geosynthetics as reinforcement on soft ground for buildings in coastal Andhra Pradesh
Authors: Haritha M , Krishnamurthy N R
Published: January 2023

Andhra Pradesh is a well-known coastal state in India, Some of the regions, the ground is soft clay in nature shows the soil has low bearing capacity and high compressibility characteristics, so ground improvement techniques may be a viable solution for the construction of any structure. Geosynthetics are the most often utilized reinforcing material in design of foundation in such soils. The significant design parameters are Modulus of subgrade reaction (K), California bearing ratio (CBR) and Modulus of elasticity (E). In Machilipatnam area, the soil is weak and having high compressibility characteristics. Hence ground improvement technique by using Geosynthetics (geotextile as separator, geogrid as reinforcement, GSB as a filling material) is adopted for two major project buildings. Field tests such as Modulus of subgrade reaction test, Plate load test were conducted over the improved ground to ascertain the quality of improvement. Furthermore, a correlation between K and CBR, E and CBR is established. The corresponding California bearing ratio values are correlated using IRC58-1988. A comparison was made over the untreated ground using correlation of E and CBR from others to know the behaviour of unreinforced and reinforced soils.