bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface dielectric barrier discharge with trenches in insulating material
Authors: Zhang Zelin
Published: December 2022

The defects within the surface of the insulating material considerably influence the performance of the dielectric barrier. The trenches are one of the foremost common defects usually caused by the impact of hit and chemical corrosion. The trenches within the surface can change the propagation path of the streamers and the volumetric force produced. In this work, a two-dimensional self-consistent fluid model was built to study surface dielectric barrier discharge with trenches within the surface of the dielectric barrier, including electron density distribution, surface charge evolution, and electric parameters. The results indicate that with the increase in trenches' depth, the streamer will diffuse outward into the ambient air, which is closely related to the ionization and electric field distortion in the trenches and at the edge of the trenches. With different sequences of the trenches in the dielectric, the deeper trench is the dominate role in changing the streamer propagation path. The distorted orientation and value of the electric field in and on the trenches account for the differences. Compared with the discharge on the flat dielectric, the diffusion of plasma and propagation distance is enhanced with the increase in the trenches' depth, bringing larger dealing area and targeted species distributions.
Array buoys with nonlinear stiffness enhance low-frequency wave attenuation and energy capture
Authors: Jin Huaqing , Zhang Haicheng , Xu Daolin
Published: December 2022

Extraction of energy and elimination of ocean waves at low frequencies are challenges facing current wave energy devices. A recent idea based on reducing the equivalent stiffness has been applied to such devices for low-frequency wave attenuation and energy capture. This study investigates a model of an array of buoys with an additional nonlinear stiffness mechanism to this end. The problems of hydrodynamic interaction between multiple floating bodies and interactions among nonlinear wave structures are solved by a semi-analytical method that combines the eigenfunction matching expansion method with the multi-harmonic balance method. The physical mechanism of the proposed nonlinear system of multiple buoys was explored, and it was found to deliver good performance in terms of power capture and wave elimination due to its “phase control” feature. Bragg resonance occurred in the arrayed buoys, which was not conducive to hydrodynamic efficiency. The properties of the multi-buoy system were evaluated, and it was found to be superior to a single buoy of equal volume. The results of this study indicate that an attached mechanism with nonlinear stiffness can be beneficial both for exploiting wave energy and reducing transmitted waves.
Enhancing the optical and electrical properties of AlGaN ultraviolet-C micro-LED via a hybrid scheme of plasma and chemical treatment
Authors: Feng Feng , Liu Yibo , Zhang Ke , Zhanghu Mengyuan , Chan Ka-Wah , Xu Ke , Kwok Hoi-Sing , Liu Zhaojun
Published: December 2022

Ultraviolet band C (UV-C) micro light-emitting diodes (micro-LEDs) provide a high energy light emission of 200–280 nm, which are brilliantly utilized in optogenetics, communications, and fluorescence. However, the limited device efficiency notably restricts the grand potential application field. In this work, three types of 20 × 20 μm2 UV-C micro-LEDs with the peak wavelength of 269 nm are fabricated by different etching strategies, including an inductively coupled plasma (ICP), post-ICP tetramethylammonium hydroxide, and a hybrid scheme combining plasma and chemical treatment. By enhancing the radiative recombination and light extraction, the hybrid scheme improves the peak external quantum efficiency of UV-C micro-LEDs to 3.45%, an elevation of 57.5% compared with ICP. A step advance in the forward injection current and ideality factor is also found on the devices fabricated by the hybrid scheme due to better contact on the AlGaN surface.
A novel optimization algorithm for the selective frequency damping parameters
Authors: Li Feifan , Ji Chunning , Xu Dong
Published: December 2022

Flow stability analysis is of great importance in flow physics and control. The solution of base flow, achieved as the steady state of the unsteady Navier–Stokes equation (UNSE), counts among keystones in the field of flow stability analysis. To obtain the numerical solution of base flow, the selective frequency damping (SFD) method has been widely used, with the numerical effectivity and computational efficiency being closely related to the selection of a pair of parameters (χ,Δ), where χ represents the control coefficient and Δ denotes the filter width. In the present work, a novel method for calculating the base flow of the unsteady Navier–Stokes equation (UNSE) has been established, by combining the SFD method with the immersed boundary method. Detailed analysis of the influences of the SFD parameters is presented, attempting to establish the relationships between the parameters and eigenvalues for the Jacobian matrix of UNSE. The dynamic mode decomposition method is introduced to calculate the eigenvalues for the velocity field, and several techniques and strategies are applied for improving the solving accuracy. Further, an optimization method of the parameter pair is developed to accelerate the convergence to the steady state, trying to minimize the spectral radius of the Jacobian matrix in the parameter space of (χ,Δ). Two test simulations, that is, flow past a cylinder and flow past two side-by-side cylinders at Re=100, are conducted by applying the optimization method. A faster convergence rate and higher efficiency are demonstrated compared to the results using the previous methods.
Nonlinear optical interactions in focused beams and nanosized structures
Authors: Amber Zeeshan H. , Spychala Kai J. , Eng Lukas M. , Rüsing Michael
Published: December 2022

Thin-film materials from μm thickness down to single-atomic-layered 2D materials play a central role in many novel electronic and optical applications. Coherent, nonlinear optical (NLO) μ-spectroscopy offers insight into the local thickness, stacking order, symmetry, or electronic and vibrational properties. Thin films and 2D materials are usually supported on multi-layered substrates leading to (multi-)reflections, interference, or phase jumps at interfaces during μ-spectroscopy, which all can make the interpretation of experiments particularly challenging. The disentanglement of the influence parameters can be achieved via rigorous theoretical analysis. In this work, we compare two self-developed modeling approaches, a semi-analytical and a fully vectorial model, to experiments carried out in thin-film geometry for two archetypal NLO processes, second-harmonic and third-harmonic generation. In particular, we demonstrate that thin-film interference and phase matching do heavily influence the signal strength. Furthermore, we work out key differences between three and four photon processes, such as the role of the Gouy-phase shift and the focal position. Last, we can show that a relatively simple semi-analytical model, despite its limitations, is able to accurately describe experiments at a significantly lower computational cost as compared to a full vectorial modeling. This study lays the groundwork for performing quantitative NLO μ-spectroscopy on thin films and 2D materials, as it identifies and quantifies the impact of the corresponding sample and setup parameters on the NLO signal, in order to distinguish them from genuine material properties.
X-ray spectroscopy of laser produced Al plasma near the target surface in a laser ion source
Authors: Lu Y. T. , Shao C. J. , Zhang J. J. , An L. F. , Sun L. T. , Zhao H. Y. , Zhao H. W.
Published: December 2022

The spatially resolved x-ray spectrum of a laser produced Al plasma near the target surface has been obtained in the energy range of 1.5–2.2 keV using a compact flat crystal spectrometer. The widely used temperature and density diagnostics, the line ratios of Lyα/Heβ and IC/Heα, were measured and compared with the calculation results of a steady-state collisional-radiative model so that the temperature and density profiles with a spatial resolution of 55 µm were obtained within 200 µm from the target plane. The plasma parameters derived from the spatially integrated spectrum were used to calculate the ionization state distribution near the target surface with the steady-state model, and the result was compared with the ion charge state distribution measured with an Electrostatic Ion Analyzer (EIA) at a distance of 4.2 m from the target surface. The validity of the steady-state model and the difference between the calculated ion charge state distribution and that measured with the EIA are discussed.
Modal analysis of propeller wake dynamics under different inflow conditions
Authors: Sun Cong , Wang Lianzhou
Published: December 2022

The evolution mechanisms from near to far field of propeller wakes under different inflow conditions were analyzed. Modal decomposition was performed on the propeller wakes calculated by previous numerical simulations [Wang et al., “Propeller wake instabilities under turbulent-inflow conditions,” Phys. Fluids 34, 085108 (2022)]. In particular, the Sparsity-Promoting Dynamic Mode Decomposition (SPDMD) was employed to identify the flow modes that play a dominant role in the inception mechanisms of the propeller wake destabilization. The results showed that the turbulent inflow contributes to the destabilization process of the tip vortex system under the low-turbulence inflow condition, and as a perturbation, it accelerates the interference between adjacent tip-vortex structures, intensifies the instability motion of the tip vortex, and then accelerates the breakdown of the tip vortex system. SPDMD succeeds in selecting a subset of dynamic mode decomposition modes that have the most substantial influence on the quality of approximation of the snapshot sequence. The present study further extends knowledge of propeller wake instability inception mechanisms under different inflow conditions, which can support the development and improvement of next-generation propellers.
Massive object velocity method for clock synchronization
Authors: Baney Douglas M.
Published: December 2022

A clock synchronization method is presented based on temporal calibration obtained via the propagation of a massive object. The calibrated massive object velocity combined with launch and receive synchronizations allows synchronization of a distal clock. This approach is an alternative to classical electromagnetic synchronization methods and the slow clock transport concept. The method is presented as an analog to electromagnetic clock synchronization. Relativistic effects and local synchronization between the object and clock are discussed.
Unified inviscid dispersion relation and Ohnesorge number effect on the rivulet instability
Authors: Wang Binxu , Tao Jianjun
Published: December 2022

Effects of the Ohnesorge (Oh) number and contact angle on the instability of a sessile rivulet are theoretically studied in this paper for both the pinned contact line (PCL) and moving contact line with invariant contact angle (MCL) conditions. Inviscid dispersion relations of unstable modes for rivulets with different static contact angles are shown to be transformed analytically into a unified form for both PCL and MCL conditions, reflecting the same intrinsic instability mechanism. The growth rate becomes lower at higher Oh due to the stabilization effect of viscosity. It is found for both PCL and MCL conditions that the deviation of the maximum growth rate from its inviscid counterpart varies as Oh1/2 when Oh is so small that the viscous effect mainly exists in a thin layer near the wall. For the MCL condition, the maximum growth rate of the unstable mode decreases and increases monotonically with the augment of the static contact angle at low and high Oh, respectively, while at moderate Ohnesorge numbers, increasing the static contact angle will first enlarge and then decrease the maximum growth rate for cases with hydrophilic bottom walls.
Electrochemistry in the Wild
Authors: Reeves-McLaren Nik
Published: December 2022

Having learned how diffraction and both in situ and operando experiments work, in this chapter we turn to looking at how these methods have been applied to better understand a range of different materials for lithium-ion, lithiumȓsulfur, lithium–air, and sodium-ion battery applications. In each case, we touch on key emergent candidate materials for next-generation devices with the aim to inform—and to inspire the reader to think about how the approaches used may well be of use in their own work.
Migrant and refugee youth perspectives on sexual and reproductive health and rights in Australia: a systematic review
Authors: Napier-Raman Sharanya , Hossain Syeda Zakia , Lee Mi-Joung , Mpofu Elias , Liamputtong Pranee , Dune Tinashe
Published: December 2022

Migrant and refugee youth (MRY) in Australia face specific experiences that inform their sexual and reproductive health and rights (SRHR). Migrant and refugee communities experience poor health outcomes and low service uptake. Additionally, youth are vulnerable to poor sexual health. This review examines the understandings and perspectives of MRY. A systematic review was conducted as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The protocol is registered with PROSPERO: CRD42021241213. Nine databases were systematically searched. Inclusion criteria specified literature reporting on migrant and/or refugee youth perspectives and attitudes towards sexual and reproductive health; peer-reviewed qualitative, mixed-methods and/or quantitative studies or grey literature reports; records using Australian research; literature published in English between January 2000 and March 2021. Records that did not report on MRY and did not examine participant views or perspectives; were abstract-only, reviews, pamphlets, protocols, opinion pieces or letters; did not include Australian research; were published before 2000 and/or in a language other than English were excluded. Two reviewers screened titles, abstracts and full-text articles. The Mixed Method Appraisal Tool was used to assess studies’ methodological quality. Thematic synthesis methods guided data extraction and analysis. Twenty-eight papers were included in the final review. Three themes were identified in MRY constructions of SRHR: (1) experiences of silence and shame; (2) understandings of and responses to SRHR risks; (3) navigation of relationships and sexual activity. Socioecological factors shaped MRY perspectives at individual, interpersonal, institutional and societal levels. Societal factors and interpersonal relationships significantly influenced decision making.
Age-related brain atrophy is not a homogenous process: Different functional brain networks associate differentially with aging and blood factors
Authors: Markov Nikola T. , Lindbergh Cutter A. , Staffaroni Adam M. , Perez Kevin , Stevens Michael , Nguyen Khiem , Murad Natalia F. , Fonseca Corrina , Campisi Judith , Kramer Joel , Furman David
Published: December 2022

Aging is characterized by a progressive loss of brain volume at an estimated rate of 5% per decade after age 40. While these morphometric changes, especially those affecting gray matter and atrophy of the temporal lobe, are predictors of cognitive performance, the strong association with aging obscures the potential parallel, but more specific role, of individual subject physiology. Here, we studied a cohort of 554 human subjects who were monitored using structural MRI scans and blood immune protein concentrations. Using machine learning, we derived a cytokine clock (CyClo), which predicted age with good accuracy (Mean Absolute Error = 6 y) based on the expression of a subset of immune proteins. These proteins included, among others, Placenta Growth Factor (PLGF) and Vascular Endothelial Growth Factor (VEGF), both involved in angiogenesis, the chemoattractant vascular cell adhesion molecule 1 (VCAM-1), the canonical inflammatory proteins interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα), the chemoattractant IP-10 (CXCL10), and eotaxin-1 (CCL11), previously involved in brain disorders. Age, sex, and the CyClo were independently associated with different functionally defined cortical networks in the brain. While age was mostly correlated with changes in the somatomotor system, sex was associated with variability in the frontoparietal, ventral attention, and visual networks. Significant canonical correlation was observed for the CyClo and the default mode, limbic, and dorsal attention networks, indicating that immune circulating proteins preferentially affect brain processes such as focused attention, emotion, memory, response to social stress, internal evaluation, and access to consciousness. Thus, we identified immune biomarkers of brain aging which could be potential therapeutic targets for the prevention of age-related cognitive decline.
Transgenerational transmission of aspartame-induced anxiety and changes in glutamate-GABA signaling and gene expression in the amygdala
Authors: Jones Sara K. , McCarthy Deirdre M. , Vied Cynthia , Stanwood Gregg D. , Schatschneider Chris , Bhide Pradeep G.
Published: December 2022

We report the effects of aspartame on anxiety-like behavior, neurotransmitter signaling and gene expression in the amygdala, a brain region associated with the regulation of anxiety and fear responses. C57BL/6 mice consumed drinking water containing 0.015% or 0.03% aspartame, a dose equivalent of 8 to 15% of the FDA recommended maximum human daily intake, or plain drinking water. Robust anxiety-like behavior (evaluated using open field test and elevated zero maze) was observed in male and female mice consuming the aspartame-containing water. Diazepam, an allosteric modulator of the GABA-A receptor, alleviated the anxiety-like behavior. RNA sequencing of the amygdala followed by KEGG biological pathway analysis of differentially expressed genes showed glutamatergic and GABAergic synapse pathways as significantly enriched. Quantitative PCR showed upregulation of mRNA for the glutamate NMDA receptor subunit 2D (
Grin2d
) and metabotropic receptor 4 (
Grm4
) and downregulation of the GABA-A receptor associated protein (
Gabarap
) mRNA. Thus, taken together, our diazepam and gene expression data show that aspartame consumption shifted the excitation-inhibition equilibrium in the amygdala toward excitation. Even more strikingly, the anxiety-like behavior, its response to diazepam, and changes in amygdala gene expression were transmitted to male and female offspring in two generations descending from the aspartame-exposed males. Extrapolation of the findings to humans suggests that aspartame consumption at doses below the FDA recommended maximum daily intake may produce neurobehavioral changes in aspartame-consuming individuals and their descendants. Thus, human population at risk of aspartame’s potential mental health effects may be larger than current expectations, which only include aspartame-consuming individuals.
Chronotopes of war and dread in pandemic times
Authors: Perrino Sabina M.
Published: December 2022

During the first months of 2020, our everyday life suddenly changed when the novel Coronavirus started to infect humans at a very fast rate, causing serious respiratory and other diseases, death, and fear of the unknown. Local friends and family members shared traumatic stories, images, and videoclips about death and dread in Northern Italy, where the first confirmed COVID-19 cases were discovered, just two months after the virus was first detected in Wuhan, China (Worobey, 2021). Inspired byBakhtin’s (1981)notion of chronotope, by autoethnography and phenomenology, within a linguistic anthropological framework, this article examines how individuals have been embodying COVID-19 related uncertainties and fears in their everyday life. Through the analysis of (auto)ethnographic narratives, recontextualized images and videoclips, including the ones related to the 1918–1920 influenza pandemic, I show how regionalizedchronotopes of warand more globalchronotopes of dreadhave emerged and solidified across pandemic times.
Wafer level hermetic bonding and packaging using recrystallized parylene
Authors: Maharshi Vikram , Ahmad Imran , Agarwal Ajay , Mitra Bhaskar
Published: December 2022

This work reports a wafer-level vacuum packaging technique for microelectromechanical system (MEMS) using recrystallized parylene material as a bonding layer. The effect of thermal annealing on the crystallinity of the parylene surface was demonstrated. The low-temperature, stable, homogeneous, and defect-free recrystallized parylene is found as an excellent bonding material for hermetic packages, suitable for the packaging of MEMS sensors. The material’s recrystallization improves its capabilities as a moisture and air barrier. The mechanical stability of the bond interface was also investigated by measuring the package’s tensile and shear strength. In the absence of a vacuum bonding tool, a Ti getter was integrated into the cavity of the glass capping wafer to create the vacuum and test the hermeticity. The MEMS silicon Pirani gauge was used to monitor the pressure changes inside the sealed cavity. After the getter activation, it was observed that there was a decrease in the pressure from atmospheric pressure to 0.2 mbar for the first few days; after that, no noticeable change was observed. The hermeticity of the packaged device was examined, and the vacuum level inside the package remained the same for the last 70 d. The recrystallized parylene bonded micro package shows better hermeticity than the non-recrystallized parylene micro package.
Discerning the transition from electromagnetically induced transparency to Autler–Townes splitting using the decaying dressed state formalism
Authors: Mishra Abhay , Jagatap B N
Published: December 2022

We use biorthogonal basis consisting of the ‘right’ and ‘left’ eigenvectors of the effective non-Hermitian Hamiltonian of a three-level

Λ

system driven by a bi-chromatic field, and resolve the probe absorption spectrum into components corresponding to the decaying dressed states of the system. It is observed that the spectrum primarily consists of three components and two of them undergo dramatic changes when the control field Rabi frequency is changed from the low to high field regime. Based on the symmetry properties of a combination of these components, a parameter internal to the dynamics of the system is defined and is used to distinguish between electromagnetically induced transparency (EIT) and Autler–Townes (AT) splitting, and the threshold for transition between them in an objective manner. The formulation is further extended to the resonance fluorescence spectrum on the probe transition in the EIT and AT regimes.
Spin Josephson effects of spin–orbit-coupled Bose–Einstein condensates in a non-Hermitian double well
Authors: Tang Jia , Hu Zhou , Zeng Zhao-Yun , Xiao Jinpeng , Li Lei , Chen Yajiang , Chen Ai-Xi , Luo Xiaobing
Published: December 2022

In this paper, we investigate the spin and tunneling dynamics of a spin–orbit-coupled noninteracting Bose–Einstein condensate in a periodically driven non-Hermitian double-well potential. Under high-frequency driving, we obtain the effective time-averaged Hamiltonian by using the standard time-averaging method, and analytically calculate the Floquet quasienergies, revealing that the parity-time (

)-breaking phase transition appears even for arbitrarily small non-Hermitian parameters when the spin–orbit coupling strength takes half-integer value, irrespective of the values of other parameters used. When the system is

-symmetric with balanced gain and loss, we find numerically and analytically that in the broken

-symmetric regions, there will exist the net spin current together with a vanishing atomic current, if we drop the contribution of the exponential growth of the norm to the current behaviors. When the system is non-

-symmetric, though the quasienergies are partial complex, a stable net spin current can be generated by controlling the periodic driving field, which is accompanied by a spatial localization of the condensate in the well with gain. The results deepen the understanding of non-Hermitian physics and could be useful for engineering a variety of devices for spintronics.
Optimizing the magnetic and giant magneto-impedance (GMI) properties of glass-coated amorphous Co-based wires via single- and two-step direct current annealing
Authors: Liu Caiyun , Liu Binbin , Xu Zerui , Zhou Guohua , Wilde Gerhard , Ye Feng
Published: December 2022

The effects of both single- and two-step direct current (DC) annealing procedures on the magnetic properties (including the giant magneto-impedance (GMI)) of glass-coated Co66Fe6Si13B15 amorphous wires were evaluated. For both methods, the GMI ratio initially increased with the current intensity and reached a peak value before declining at higher current intensities. A maximum improvement of the GMI ratio of about five times was obtained for the two-step DC-annealed sample, while that for single-step DC-annealed samples was only 2.44 times. A higher GMI sensitivity was also observed for the two-step DC-annealed wires. The better GMI performance of the two-step DC annealed samples was attributed to the more homogeneously distributed precipitation in the matrix and the ordered circumferential magnetic domains on the surface. The results obtained further imply that DC annealing at a higher current intensity but over a shorter treatment time is a more efficient and energy-saving method for enhancing the GMI performance of Co-based amorphous wires for potential industrial applications.
Mechanical properties and multifunctionality of AlB2-type transition metal diborides
*
Authors: Li Zhuang , Zhao Bo , Wang Lu , Tao Qiang , Zhu Pinwen
Published: December 2022

Transition metal diborides (TMdBs, P6/mmm, AlB2-type) have attracted much attention for decades, due to TMdBs can be conductors, superconductors, magnetism materials, and catalysts. The layered structure caused by the borophene subunit is the source of functions and also makes TMdBs a potential bank of Mbene. However, TMdBs also exhibit high hardness which is not supposed to have in the layered structure. The high hardness of TMdBs arises from covalent bonds of boron–boron (B–B) and strong p–d orbit hybridization of B and TM. While strong B–TM bonds will eliminate the layered structure which may damage the functional properties. Understanding the basic mechanism of hardness and function is significant to achieve optimal TMdBs. This work summarizes the basic properties of TMdBs including hardness, superconductor, and catalytic properties. It can be found that Young’s modulus (E) and Shear modulus (G) are beneficial for the hardness of TMdBs and the Poisson’s ratio is the opposite. Increasing the atomic radius of TM brings an improvement in the hardness of TMdBs before it reaches the highest value of 1.47 Å, beyond which hardness decreases. Besides, TMdBs also have excellent activity comparable with some noble metals for hydrogen evolution reaction, which is closely related to the d-band center. More importantly, higher valence electron concentrations were found to be adverse to the hardness and superconductivity of TMdBs and greatly affect their catalytic properties. This review is of guiding significance for further exploring the relationship between structures and properties of TMdBs.
Fast and accurate 3D topography measurement based on a novel synthesis pattern method
Authors: Zheng Renhao , Wan Maosen , Zhang Wei , Yu Liandong
Published: December 2022

Prompt and accurate measurement of the three-dimensional (3D) contours of complex surfaces is currently a key research direction. In the current study, we presented a fast grayscale stripe synthesis method based on focused binary patterns. Specifically, by encoding a group of binary patterns, the patterns were captured by the camera within one exposure time cycle and synthesized into a grayscale-intensity triangular wave stripe pattern. Importantly, this method utilized the fast projection rate of the binary pattern, improved the speed of stripe projection, and prevented nonlinearity in the 3D measurement of stripe projection by synthesizing the gray pattern in the form of a binary pattern.
Charge transfer effect: a new assignment of the abnormal optical absorption band of gold nanoparticles
Authors: Shi Lexian , Wang Can , Su Dong , Zhang Lisheng , Wang Peijie , Fang Yan
Published: December 2022

As a significant accompanying phenomenon of surface-enhanced Raman scattering (SERS), the addition of foreign molecules to colloidal gold or silver nanoparticles results in a new abnormal optical absorption (AOA) band, which usually appears in the long-wavelength region. The assignment of this AOA band has long been debated as an important issue that is desired to be addressed in the SERS field, which is crucial for a clear understanding of the SERS enhancement mechanism and beneficial to surface plasmonics. In this study, both the calculated and measured optical absorptions of gold nanoparticle monomers and dimers as well as their interactions with adsorbed molecules, showed that the AOA band in the long-wavelength region which was assigned to the characteristic longitudinal localized surface plasmon resonance (LSPR) effect of gold nanoparticle chain aggregates in conventional SERS electromagnetic theory, should be attributed to the charge-transfer resonance absorption from gold nanoparticles to adsorbed molecules. This was further confirmed by the corresponding SERS effects. As the excitation wavelength at 785 nm was resonant with the broad AOA band centered at 750 nm, the SERS peaks of the adsorbed pyridine molecules could be dramatically enhanced due to the charge-transfer resonance effect. In contrast, under an excitation wavelength of 532 nm, the SERS peaks appeared very weak, although the excitation wavelength was resonant with the LSPR absorption band of the individual gold nanoparticles.
Towards the characterization of the tumor microenvironment through dictionary learning-based interpretable classification of multiplexed immunofluorescence images
Authors: Krishnan Santhoshi N , Barua Souptik , Frankel Timothy L , Rao Arvind
Published: December 2022

Objective. Histology image analysis is a crucial diagnostic step in staging and treatment planning, especially for cancerous lesions. With the increasing adoption of computational methods for image analysis, significant strides are being made to improve the performance metrics of image segmentation and classification frameworks. However, many developed frameworks effectively function as black boxes, granting minimal context to the decision-making process. Thus, there is a need to develop methods that offer reasonable discriminatory power and a biologically-informed intuition to the decision-making process. Approach. In this study, we utilized and modified a discriminative feature-based dictionary learning (DFDL) paradigm to generate a classification framework that allows for discrimination between two distinct clinical histologies. This framework allows us (i) to discriminate between 2 clinically distinct diseases or histologies and (ii) provides interpretable group-specific representative dictionary image patches, or ‘atoms’, generated during classifier training. This implementation is performed on multiplexed immunofluorescence images from two separate patient cohorts- a pancreatic cohort consisting of cancerous and non-cancerous tissues and a metastatic non-small cell lung cancer (mNSCLC) cohort of responders and non-responders to an immunotherapeutic treatment regimen. The analysis was done at both the image-level and subject-level. Five cell types were selected, namely, epithelial cells, cytotoxic lymphocytes, antigen presenting cells, HelperT cells, and T-regulatory cells, as our phenotypes of interest. Results. We showed that DFDL had significant discriminant capabilities for both the pancreatic pathologies cohort (subject-level AUC-0.8878) and the mNSCLC immunotherapy response cohort (subject-level AUC-0.7221). The secondary analysis also showed that more than 50% of the obtained dictionary atoms from the classifier contained biologically relevant information. Significance. Our method shows that the generated dictionary features can help distinguish patients presenting two different histologies with strong sensitivity and specificity metrics. These features allow for an additional layer of model interpretability, a highly desirable element in clinical applications for identifying novel biological phenomena.
Introduce a rotational robust optimization framework for spot-scanning proton arc (SPArc) therapy
Authors: Chang Sheng , Liu Gang , Zhao Lewei , Zheng Weili , Yan Di , Chen Peter , Li Xiangpan , Deraniyagala Rohan , Stevens Craig , Grills Inga , Chinnaiyan Prakash , Li Xiaoqiang , Ding Xuanfeng
Published: December 2022

Objective. Proton dosimetric uncertainties resulting from the patient’s daily setup errors in rotational directions exist even with advanced image-guided radiotherapy techniques. Thus, we developed a new rotational robust optimization SPArc algorithm (SPArcrot) to mitigate the dosimetric impact of the rotational setup error in Raystation ver. 6.02 (RaySearch Laboratory AB, Stockholm, Sweden). Approach. The initial planning CT was rotated ±5° simulating the worst-case setup error in the roll direction. The SPArcrot uses a multi-CT robust optimization framework by taking into account of such rotational setup errors. Five cases representing different disease sites were evaluated. Both SPArcoriginal and SPArcrot plans were generated using the same translational robust optimized parameters. To quantitatively investigate the mitigation effect from the rotational setup errors, all plans were recalculated using a series of pseudo-CT with rotational setup error (±1°/±2°/±3°/±5°). Dosimetric metrics such as D98% of CTV, and 3D gamma analysis were used to assess the dose distribution changes in the target and OARs. Main results. The magnitudes of dosimetric changes in the targets due to rotational setup error were significantly reduced by the SPArcrot compared to SPArc in all cases. The uncertainties of the max dose to the OARs, such as brainstem, spinal cord and esophagus were significantly reduced using SPArcrot. The uncertainties of the mean dose to the OARs such as liver and oral cavity, parotid were comparable between the two planning techniques. The gamma passing rate (3%/3 mm) was significantly improved for CTV of all tumor sites through SPArcrot. Significance. Rotational setup error is one of the major issues which could lead to significant dose perturbations. SPArcrot planning approach can consider such rotational error from patient setup or gantry rotation error by effectively mitigating the dose uncertainties to the target and in the adjunct series OARs.
A probability model for anatomical robust optimisation in head and neck cancer proton therapy
Authors: Zhang Ying , Alshaikhi Jailan , Tan Wenyong , Royle Gary , Bär Esther
Published: December 2022

Objective. Develop an anatomical model based on the statistics of the population data and evaluate the model for anatomical robust optimisation in head and neck cancer proton therapy. Approach. Deformable image registration was used to build the probability model (PM) that captured the major deformation from patient population data and quantified the probability of each deformation. A cohort of 20 nasopharynx patients was included in this retrospective study. Each patient had a planning CT and 6 weekly CTs during radiotherapy. We applied the model to 5 test patients. Each test patient used the remaining 19 training patients to build the PM and estimate the likelihood of a certain anatomical deformation to happen. For each test patient, a spot scanning proton plan was created. The PM was evaluated using proton spot location deviation and dose distribution. Main results. Using the proton spot range, the PM can simulate small non-rigid variations in the first treatment week within 0.21 ± 0.13 mm. For overall anatomical uncertainty prediction, the PM can reduce anatomical uncertainty from 4.47 ± 1.23 mm (no model) to 1.49 ± 1.08 mm at week 6. The 95% confidence interval (CI) of dose metric variations caused by actual anatomical deformations in the first week is −0.59% ∼ −0.31% for low-risk CT D
95, and 0.84–3.04 Gy for parotid D
mean. On the other hand, the 95% CI of dose metric variations simulated by the PM at the first week is −0.52 ∼ −0.34% for low-risk CTV D
95, and 0.58 ∼ 2.22 Gy for parotid D
mean. Significance. The PM improves the estimation accuracy of anatomical uncertainty compared to the previous models and does not depend on the acquisition of the weekly CTs during the treatment. We also provided a solution to quantify the probability of an anatomical deformation. The potential of the model for anatomical robust optimisation is discussed.
Effective six-band model and unconventional spin-singlet pairing in Kagome superconductor CsV3Sb5
Authors: Bai Xiao-Cheng , Wu Wen-Feng , Wang Han-Yu , Quan Ya-Min , Wang Xianlong , Zeng Zhi , Zou Liang-Jian
Published: December 2022

Recently synthesized Kagome compounds AV3Sb5 attract great attention due to the unusual coexistence of the topology, charge density wave, and superconductivity. In this work, based on the band structures for CsV3Sb5 in the pristine phase, we construct an effective six-band model for the low-energy processes; utilizing the random phase approximation on the effective six-band model, we show that the

E

1
u

(p wave) pairing dominates in the region of

0
<
U
<
0.32

 eV, the

A

2
g

(I wave) in the region of

0.32
<
U
<
0.75

 eV and the

E

2
g

(d wave) in the region of

0.75
<
U
<
1

 eV. Considering that the correlation in AV3Sb5 is weak or intermediate, these results suggest that pairing symmetry is

A

2
g

(I-wave) in the CsV3Sb5, which can explain some recent experiments about pairing symmetry.
Heat transport in an optical lattice via Markovian feedback control
Authors: Wu Ling-Na , Eckardt André
Published: December 2022

Ultracold atoms offer a unique opportunity to study many-body physics in a clean and well-controlled environment. However, the isolated nature of quantum gases makes it difficult to study transport properties of the system, which are among the key observables in condensed matter physics. In this work, we employ Markovian feedback control to synthesize two effective thermal baths that couple to the boundaries of a one-dimensional Bose–Hubbard chain. This allows for the realization of a heat-current-carrying state. We investigate the steady-state heat current, including its scaling with system size and its response to disorder. In order to study large systems, we use semi-classical Monte-Carlo simulation and kinetic theory. The numerical results from both approaches show, as expected, that for non- and weakly interacting systems with and without disorder one finds the same scaling of the heat current with respect to the system size as it is found for systems coupled to thermal baths. Finally, we propose and test a scheme for measuring the energy flow. Thus, we provide a route for the quantum simulation of heat-current-carrying steady states of matter in atomic quantum gases.
Evaluating the corrosion resistance of marine steels under different exposure environments via machine learning
Authors: Li Zhuang , Long Zhilin , Lei Shan , Liu Xiaowei , Yang Lingming , Zhang Wei , Zhang Ting
Published: December 2022

The corrosion behavior of marine engineering steels in marine environment is an extremely complex process, which poses great challenge to accurately evaluate the corrosion resistance of various stees in different marine environment. Owing to the wide application of machine learning (ML) approaches and the accumulation of corrosion data of different steels in natural marine environment, herein, we reported eXtreme Gradient Boosting (XGBoost) ML models for predicting the corrosion rate in submerged, tidal and splash zones. By taking material composition, environmental factors and exposure time as inputs, the developed prediction models can well predict the corrosion rate with the accuracy of 93%, 96% and 93% for submerged, tidal and splash zones, respectively. In addition, we identified the key factors affecting the corrosion resistance of steels in different marine zones, and analyzed the relationship between these factors and corrosion rate by applying SHapley Additive exPlanations (SHAP) method. This work demonstrates that ML model combined with SHAP method are efficient in evaluating corrosion behavior of various steels in different marine environment.
Investigating structural, electronic, magnetic, and optical properties of Zr doped and Ti-Zr co-doped GaN for optoelectronic applications
Authors: Junaid Iqbal Khan M , Liu Juan , Batool Saima , Latif Abid , Majeed Iqra , Yousaf M , Taj Imran , Ullah Hamid , Mustansar Zartasha , Yousaf Masood , Ahmad Javed , Asghar Mazia
Published: December 2022

Search of new novel materials for bringing advancement in the field of energy storage and optical materials is tremendously growing in order to meet future challenges. Gallium nitride (GaN) shows exceptional optoelectronic behavior which is highly needed for production of optoelectronic devices. Therefore, in this research study, we investigate the structural, electronic, magnetic, and optical properties of pure GaN, titanium doped GaN (Ti@GaN), zirconium doped GaN (Zr@GaN) and Ti-Zr co-doped GaN using the Wien2k code. Proactive role of dopants Ti and Zr d-states is observed which appreciably tune electronic properties. GaN remains non-magnetic after zirconium substitution with Ga atom however, Ti doping and Ti-Zr co-doping produce magnetism into GaN with total magnetic moments of 0.99

μ

B

,

and 1.503

μ

B

,

respectively. Substitution of Ti/Zr into GaN may be more favorable at N-rich conditions due to lower formation energy. Absorption spectrum of Ti@GaN and Zr@GaN show blueshift while for Ti-Zr@GaN material exhibit redshift. However, absorption spectra of both proposed materials significantly enhanced in the UV region which propose their potential uses in the high power UV optoelectronics, spintronics, photonics devices and in solid state nano-emitters.
A theoretical approach for quantum memory based on modified superradiance lattice
Authors: Shabbir Atif , Qamar Sajid
Published: December 2022

We propose modified superradiance lattice (MSL) based scheme to realize quantum memory where intensity of the control field plays an important role in achieving high storage efficiency. We report that via proposed scheme one can store light with 96% storage efficiency having corresponding fidelity of 99% and group delay 1 μs. We notice that the group delay can be enhanced to 10 μs via manipulation of the control field, however, the storage efficiency is reduced to 87%. The benefit of considering MSL for the quantum memory is that one can obtain directional light. The main advantage of the proposed scheme is that it does not require large optical depth to obtain high storage efficiency, which makes it experimentally more viable.
Search for spatial coincidence between IceCube neutrinos and radio pulsars
Authors: Pasumarti Vibhavasu , Desai Shantanu
Published: December 2022

We search for a spatial association between radio pulsars and ultra-high energy neutrinos using the publicly available IceCube point source neutrino events catalog. For this purpose we use the unbinned maximum likelihood method to search for a statistically significant excess from each of the pulsars in the ATNF catalog. We do not find any pulsars with detection significance much higher than that expected from a Gaussian distribution, Therefore, we conclude that none of the currently known pulsars contribute to the diffuse neutrino flux detected by IceCube.
Ion migration in metal halide perovskite QLEDs and its inhibition
Authors: Dong Yuhui , Yan Danni , Yang Shuai , Wei Naiwei , Zou Yousheng , Zeng Haibo
Published: December 2022

Benefiting from the excellent properties such as high photoluminescence quantum yield (PLQY), wide gamut range, and narrow emission linewidth, as well as low-temperature processability, metal halide perovskite quantum dots (QDs) have attracted wide attention from researchers. Despite tremendous progress has been made during the past several years, the commercialization of perovskite QDs-based LEDs (PeQLEDs) is still plagued by the instability. The ion migration in halide perovskites is recognized as the key factor causing the performance degradation of PeQLEDs. In this review, the elements species of ion migration, the effects of ion migration on device performance and stability, and effective strategies to hinder/mitigate ion migration in PeQLEDs are successively discussed. Finally, the forward insights on the future research are highlighted.
Dislocation mechanism of Ni47Co53 alloy during rapid solidification
Authors: Liu Yun-Chun , Liang Yong-Chao , Chen Qian , Zhang Li , Ma Jia-Jun , Wang Bei , Gao Ting-Hong , Xie Quan
Published: December 2022

Dislocations and other atomic-level defects play a crucial role in determining the macroscopic properties of crystalline materials, but it is extremely difficult to observe the evolution of dislocations due to the limitations of the most advanced experimental techniques. Therefore, in this work, the rapid solidification processes of Ni47Co53 alloy at five cooling rates are studied by molecular dynamics simulation, and the evolutions of their microstructures and dislocations are investigated as well. The results show that face-centered cubic (FCC) structures are formed at the low cooling rate, and the crystalline and amorphous mixture appear at the critical cooling rate, and the amorphous are generated at the high cooling rate. The crystallization temperature and crystallinity decrease with cooling rate increasing. Dislocations are few at the cooling rates of 1 × 1011 K/s, 5 × 1012 K/s, and 1 × 1013 K/s, and they are most abundant at the cooling rates of 5 × 1011 K/s and 1 × 1012 K/s, in which their dislocation line lengths are both almost identical. There appear a large number of dislocation reactions at both cooling rates, in which the interconversion between perfect and partial dislocations is primary. The dislocation reactions are more intense at the cooling rate of 5 × 1011 K/s, and the slip of some dislocations leads to the interconversion between FCC structure and hexagonal close packed (HCP) structure, which causes the twin boundaries (TBs) to disappear. The FCC and HCP are in the same atomic layer, and dislocations are formed at the junction due to the existence of TBs at the cooling rate of 1 × 1012 K/s. The present research is important in understanding the dislocation mechanism and its influence on crystal structure at atomic scales.