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The preparation of fused silica glass with microstructural patterns has attracted considerable interest, and the process chain of using nano-silica powders mixed with organic polymers to prepare composites for molding, degreasing, and sintering provides a good solution. However, the potential negative effects of organic residues cannot be avoided. In this study, a pattern stencil replication method with silica gel using high-purity quartz fibers as reinforcement is proposed for preparing micropatterned fused silica glass. The microscopic morphology and mechanical properties before and after silica gel drying and the optical properties of fused silica glass obtained by sintering were evaluated via transmission electron microscopy), three-point bending strength test, scanning electron microscopy, X-ray diffraction spectrum analysis, ultraviolet–visible and infrared measurements. The results showed that quartz fiber as a reinforcer could shorten the drying time of the gel and did not degrade the quality of the fused silica glass obtained by sintering. Laser confocal test results showed that microlens arrays were generated by template replication, demonstrating the feasibility of molding fused silica lens arrays with small feature sizes and providing new ideas for the preparation of bulk fused silica glass or micropatterned glass. [ABSTRACT FROM AUTHOR]

The technology of p-type transparent semiconductors is utilized in various fields, and enhancing their performance holds industrial significance. Thus, improving the versatility and efficiency of the p-type transparent conducting oxides (TCO) has become critical for the semiconductor industries and technologies. To be used as hole carrier layes in optoelectronic devices, this study aimed to modify the physical features of nickel oxide (NiO) through a doping approach which may broaden and strengthen the usage of NiO. A cost-effective ultrasonic pyrolysis spray technique was employed for pure and lead (Pb) doped nickel oxide thin film production. The influence of the lead concentration on optical, structural, and morphological traits of the NiO nanostructures was examined via various analyses, including energy-dispersive X-ray spectroscopy (EDAX), scanning electron microscopy (SEM), Photoluminescence, UV–visible spectroscopy, X-Ray Diffraction, and Raman spectroscopy, were utilized to investigate the optical and structural characteristics of these films. In correlation, the X-Ray Diffraction results indicated that the Pb doping induced strain and altered lattice parameters of the grown nanostructures while the cubic phase of NiO maintained. The crystallite size of NiO samples ranged from 31.49 nm to 18.75 nm based on Pb doping concentration which was notably influenced by species and doping content. The UV–vis measurements demonstrated that optical parameters, such as optical band gap, were sensitive to Pb doping ratios. The Raman spectrum analysis confirmed the successful incorporation of Pb ions into NiO. Additionally, the intensity of the PL spectra decreased with increasing Pb content, offering potential applications as window layers in solar cells, smart windows, and other optoelectronic devices. [ABSTRACT FROM AUTHOR]

• 27-day variations of GCR flux according to measurements of AMS-02 and others. • Parameterization of the amplitude-energy spectrum of variations. • Consequences of the force-field model for short-term modulation. This work presents the results of the analysis of 27-day variations in the flux of galactic protons registered by STEREO, SOHO, and AMS-02 in 2015–2016. We calculate variations' amplitude using several different approaches and propose a description of its energy dependence in the range of magnetic rigidity from approximately 0.3 to 100 GV. We also analyse variations of the solar modulation potential, which is the only parameter of force-field model, and consider the possibility of describing the 27-day variations of galactic cosmic rays within the framework of this model. It is shown that rigidity dependence of the 27-day variations amplitude cannot be properly described using this simple approximation. [ABSTRACT FROM AUTHOR]

• Automatic selection of embedding dimension in Singular spectrum analysis is achieved. • Singular spectrum analysis yields the most stable and accurate sea level heights among the methods. • Singular spectrum analysis provides a better concentration of spectral power in the periodogram. In order to obtain reliable GNSS-R derived sea level heights (SLHs), it is crucial to extract accurate reflected signals from signal-to-noise ratio (SNR) data. In this study, Quadratic Fitting, Empirical Mode Decomposition (EMD), Ensemble Empirical Mode Decomposition (EEMD), and Singular Spectrum Analysis (SSA) are adopted for extracting the reflected signals from SNR data, which are then analyzed with Lomb Scargle Periodogram (LSP) assisted with tidal harmonic analysis for GNSS-R SLHs. Three continuous GNSS stations including Onsala in Sweden, Friday Harbor in the United States, and Brest in France with tidal ranges of approximately 1 m, 3 m, and 7 m, respectively, were used in the study. The derived SLHs were evaluated against the nearby or co-located tide gauge records. The results reveal that the three proposed algorithms effectively cope with the multi-peaks spectrum problems when using the conventional Quadratic Fitting without a priori reflected height constraint, and SSA can provide the solutions with fewer outliers among the proposed methods with the RMSEs of 6.7 cm, 13.4 cm and 39.6 cm at Onsala, Friday Harbor, and Brest stations, respectively. Without implementing tidal harmonic analysis, SSA is the method capable of acquiring reliable SLHs among the stations, as evidenced by comparing with co-located gauge records, particularly at the Brest station. In summary, SSA not only distinguishes signals across different frequencies, but also orders the signal components according to their eigenvalues, demonstrating the potential to extract the reflected signals from SNR and enhance the stability and accuracy of GNSS-R applications. [ABSTRACT FROM AUTHOR]

• Analysis of geomagnetic field's H time series during quiet geomagnetic condition. • The H time series from high latitude region shows anti-persistent behaviour. • H time series of quiet geomagnetic condition shows multifractal characteristics. • Change in multifractal characteristics with latitude is observed. • The cause of multifractality is identified as long-range correlations. The generation of geomagnetic time series frequently involves intricate spatio-temporal dynamics, wherein nonlinearity and scaling emerge as pivotal mechanisms. The present work investigates the fractal properties of geomagnetic field, and its sources during quiet geomagnetic conditions, by analyzing the horizontal component data of 1 min resolution (H time series) from different latitude regions. Analysis using Auto Correlation Function (ACF), Power spectrum analysis (PSA), Rescaled range analysis (R/S) and Detrended Fluctuation Analysis (DFA) gave indications of the presence of long-range correlations, fractal properties and scaling behaviour of quiet period H time series data. The strong q dependence of generalized Hurst exponent h(q) and scaling exponent Ʈ(q), obtained from the Multifractal Detrended Fluctuation Analysis (MFDFA) method, confirmed the multifractal behaviour of quiet period H time series. The multifractal source analysis of the quiet period H time series with its shuffled and surrogate time series data revealed that, the multifractal characteristics are caused almost entirely by the long-range correlations between small and large fluctuations. The analysis of the latitudinal variations in the multifractal characteristics is also performed as a part of the work, by considering H time series belonging to various latitudes under almost same longitude. The observed decrease in the generalized Hurst exponent values with increase in latitude indicates the change in the multifractal characteristics of the time series with latitude. Also the work revealed that, the H time series from high latitude region shows anti-persistent behaviour, even when the H time series from observatories located at the low and mid latitude regions exhibiting persistent behaviour. The change in the persistence, anti-persistence behaviour can be related to the strength of Earth's magnetic field. [ABSTRACT FROM AUTHOR]

This study successfully synthesized novel phosphors Ca 2 GaTaO 6 : x Dy3+ (CGTO: x Dy3+) and Ca 2 GaTaO 6 :0.06Dy3+, y Sm3+ (CGTO:0.06Dy3+, y Sm3+) using the high temperature solid-phase reaction preparation. The microstructure, optical properties, and energy transfer mechanism of the phosphors were studied through X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL) spectra and fluorescence lifetimes. XRD and corresponding refinement results indicate that Dy3+ and Sm3+ ions were effectively doped into the Ca 2 GaTaO 6 (CGTO) lattice. The SEM graphs show that the elements in CGTO:0.06Dy3+, 0.5Sm3+ phosphors are uniformly distributed. PL spectra analysis show the CGTO: x Dy3+ phosphors display two strong emission peaks located at 482 nm for blue emission and 575 nm for yellow emission when excited with 350 nm light. Under uniform conditions, when excited with 365 nm of light, the CGTO:0.06Dy3+, y Sm3+ phosphors emit light that can be tuned with adjustable color coordinates and correlated color temperature (CCT) by incorporating varying proportions of Sm3+ ions. This tunability is achieved through the effective energy migration from Dy3+ to Sm3+ ions within the phosphor material. Furthermore, the emission spectra and weaken lifetimes of the CGTO:0.06Dy3+, y Sm3+ confirm the energy transport between Dy3+ and Sm3+, and the energy transfer efficiency reached to 76 %. At 423 K, the luminescence intensity of CGTO:0.06Dy3+, 0.05Sm3+ phosphor retains 87 % of the intensity observed at 298 K, signifying its excellent thermal durability. Finally, the electroluminescent performance of the CGTO:0.06Dy3+ and CGTO:0.06Dy3+, 0.05Sm3+ phosphors packaged on 365 nm light-emitting diode (LED) chips respectively were studied to investigate the capability applications of the phosphors in white light-emitting diodes (WLEDs) field. The CCT of the packaged LEDs decline from 3396 to 2825 K, indicating CGTO:0.06Dy3+, 0.05Sm3+ phosphor shifts to warmer white light. At a voltage input of 3.4 V and a current of 600 mA, the thermal sensing shows that the WLEDs maintain aptitude for 90 min, showing that the packaged WLEDs can function consistently under elevated temperatures. These studies indicated the phosphors have potential applications in indoor lighting. [ABSTRACT FROM AUTHOR]

Southeastern Turkey perished by the M w 7.8, Kahramanmaras earthquake on February 6, 2023, at 01:17 UT (04:17 LT). The Kahramanmaras-centered event, hit by the break of the East Anatolian Fault Line, is felt in Syria, Egypt, Lebanon, Iraq, and Cyprus on the border of Turkey. Together with Syria, it causes loss of lives and severe damage in 10 cities. This work is dedicated to the people of the region. The study discusses the causality of anomalies by conducting ionospheric anomaly research via the interpolated TEC map obtained from the CODE according to the coordinates of the epicenter of the earthquake (latitude, longitude). The TEC amplitudes are observed by evolving the time-domain TEC map into the frequency-domain with the Fourier transform. The peaks of the amplitudes allow preliminary information for the anomaly days. For the anomaly, the TEC (TECU) boundaries are drawn by the statistical specification. The TEC map outside these boundaries is marked as an anomaly. The causality of abnormalities is tried to be read through the triad of the geomagnetic storm(s) , solar activity , and the earthquake effect. One can find seven anomaly days in the paper. January 30, February 2, 3, 11, 15, 16, and 21 are the anomaly days. The essay probably detects the anomaly before 3 days related to the Southeastern earthquake. • Reads the causality of the earthquake in southeast Turkey (Mw 7.8), through the ionosphere-earth crust relationship. • Notices potential anomalies by presenting the time-domain TEC atlas in the frequency domain with Fourier spectral analysis. • Considering all possible TEC anomaly essentials detect the precursors of the earthquake 3 days before the event day. [ABSTRACT FROM AUTHOR]

Studying the mechanisms of bagasse conversion into syngas is essential to sustain the growing use of biomass in energy economy production. In this work, the precise kinetics of bagasse gasification with various gasification agents was firstly investigated employing in-situ infrared spectra with Coats-Redfern integration, combining qualitative infrared spectroscopy allowed for kinetic analysis, so as to explore how the intermediate species vary in each basic reaction. The results demonstrate that the CO 2 agent reduces the activation energy of nitryl after amino oxidation, making the lignin involved in gasification more easily as well as causing higher gasification efficiency. On the one hand, steam serving as a gasification agent enhances the concentration of hydroxyl groups and produces H 2 -rich syngas. On the other hand, the strong oxidizing hydroxyl group reduces the energy barrier of carbonyl and carboxyl groups in cellulose, which facilitates the gasification process. Furthermore, this study compared the effects of gasification agent (H 2 O or CO 2) on syngas composition, reactor temperature distribution, carbon conversion rate, gasification efficiency, as well as low calorific value, providing essential information for understanding the micro-reaction pathways and pathway regulation during bagasse gasification. • Reducing the activation energy of functional groups are regulated by gasifiers. • The synergistic of gasification agents regulate chemical bond-breaking pathways. • The prospects of producing H 2 from biomass gasification are elucidated. [ABSTRACT FROM AUTHOR]

Software-Defined Radios are radio communications devices that have been growing and developing on a larger scale in recent years. Communications are intrinsically embedded in our day by day, thus presenting a higher motivation to use software-defined radios due to its attractive cost. However they present technical limitations. This paper addresses this problem, which is the non-linearity behaviour of gain and frequency in the LimeSDR-USB. That is, this equipment is used to produce a FM signal with an associated frequency and gain before being parameterised according to the internal parameters of each software-defined radio. Each software-defined radio presents a value of frequency and gain of its own, which correlates to the generated signals at the output level. To avoid this, machine learning networks were used, in which networks were trained to adapt to the non-linearity of these devices and correct it without the user noticing. This way, the user sets a desired frequency and gain in a signal, at the output of the software-defined radios, and a neural network calculates which values the software-defined radios should be parameterised, thus mitigating the non-linearity behaviour. This paper presents the evaluation of a laboratory prototype based on low-cost commercial software-defined radios equipment, to replace an expensive metrologically calibrated equipment used for radio frequency tests on a new concept of industrial test station, with description of the integration of Digital Twins, with their physical and virtual parts. [ABSTRACT FROM AUTHOR]

In the automotive industry, products must be tested and verified before being launched; currently, products such as automotive radio are usually tested with expensive metrology equipment, such as the Rohde & Schwarz SFE100, which produces radio frequency signals. This study assessed the feasibility of replacing the SFE100 with two inexpensive devices, Adalm-Pluto and LimeSDR usb, which are software-defined radios. For this evaluation, a study was carried out to determine specific metrological characteristics and then to compare with those of metrological equipment. Based on the results and tests of the study, we conclude that SDRs can generate test signals (FM, DAB, DVB, ISDB and SXM) with uncertainties of 0.5dBm and a spectral density ratio comparable to SFE100, thereby enabling their replacement. Furthermore, the evaluation datasets of all equipment have been publicly available [1] , enabling the scientific community to extract the metrological uncertainties for all signal carriers generated by the device. The result of this study proposes a methodology for testing auto radios that is innovative and can be applied to a production line based on the principles of Industry 4.0. [ABSTRACT FROM AUTHOR]

A series of Bi 2 Sr 2- x Ni x CaCu 2 O 8+ δ (x = 0.00, 0.10, 0.20 and 0.30) ceramics samples were synthesized by Pechini sol-gel method. In this work, the microstructure and structure stability of Ni-doped Bi2212 system were investigated particularly by X-ray diffraction, electron microscopy and high-pressure Raman spectroscopy. It is confirmed that the main phase of all samples is the typical Bi2212 tetragonal phase with space group I 4/ mmm. As Ni-doping amount x ≤ 0.20, the number of Ni atoms entering the Bi2212 lattice increases gradually with increasing x. These Ni atoms preferentially occupy Sr-sites, resulting in a gradual increase in the a and c axis lengths of Bi2212 structure. The formation of containing-Ni Bi2212 lattice is mainly derived from the insertion of sufficient Ni–O two-dimensional (2D) monomers. Contrarily, when x > 0.20, these Ni–O 2D monomers will preferentially form the NiO particle and the chance of Ni atoms entering the Bi2212 lattice is reduced, which leads to a shrinkage of Bi2212 lattice parameters. Besides, under high-pressure (0–20 GPa) condition, Raman spectrum analysis shows that the O Sr peak significantly shifts to the higher wavenumber and Bi2212 phase could still maintain the tetragonal structure, suggesting that it has a relatively high structure stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • PE and PP MPs restrain pyrolysis characteristic of DS, while PVC MPs activates it. • MPs restrains the output of gas products but improved the combustible proportion. • PVC MPs improves the aromaticity, stability and adsorption activity of SS biochar. The concentration of microplastics (MPs) in sewage sludge (SS) ranged from 1600 to 56400 particles per kilogram of dried SS (MPs: dried SS = 0.14–5.09), so its effect on SS pyrolysis performance should not be negligible. This study attempted to investigate the effect of typical MPs, including polypropylene (PP), polyethylene (PE), and polyvinyl chloride (PVC), on the pyrolysis performance (pyrolysis characteristics and major gaseous product evolution) of SS and their biochar characteristics via thermogravimetry-mass spectrometry (TG-MS) and physicochemical property analysis of biochar. The results showed that the PVC MPs enhanced the pyrolysis of SS, while the PP and PE MPs had an inhibitory effect. The total amounts of gas products tended to decrease with all MPs addition. However, the proportions of combustible components (H 2 , CH 4 , and C 2 H 2) increased. Among the biochar products, the presence of PVC MPs during the pyrolysis of SS resulted in a more porous, stable and aromatic biochar. [ABSTRACT FROM AUTHOR]

This study reports the successful synthesis and comprehensive characterization of ZrO 2 :Dy3+ phosphors with the incorporation of K+ ions. The introduction of Dy3+ and K+ in the ZrO 2 lattice as lanthanide activators demonstrates its potential as an efficient host material. The structural integrity of ZrO 2 remains unaltered following the doping process. Fourier-transform infrared spectroscopy (FTIR) analysis confirms the presence of Zr-O and O-H stretching, along with H 2 O bending modes in the phosphor sample. The wide luminescence band seen at 460 nm is attributed to luminescence defects in the ZrO 2 induced by oxygen, and the presence of water molecules. Photoluminescence (PL) spectra analysis reveals pronounced emission peaks at 491 and 578 nm, corresponding to 4F 9/2 → 6H 15/2 and 4F 9/2 → 6H 13/2 transitions, respectively, upon excitation at 349 nm. Optimizing the Dy3+ doping concentration to 0.4 wt% and achieving a critical distance of 31.82 Å resulted in efficient energy transfer. Notably, co-doping K+ as a charge compensator significantly enhances the luminescence intensity. Moreover, at lower temperatures, direct excitation of Dy3+ ions through our pump wavelength, coupled with exciton-mediated energy transfer, leads to a remarkable increase in PL intensity. Tailoring the doping concentrations effectively shifts the emission spectrum of the phosphor mixture, aligning with the standard white light illumination coordinates (0.333, 0.333). This property positions the material as a promising candidate for applications in white light-emitting diodes (WLEDs) and various high-quality lighting applications. The enhanced photoluminescence and temperature dependence observed in ZrO 2 :Dy3+ phosphors upon the incorporation of K+ ions pave the way for their potential utilization in advanced luminescent devices. [ABSTRACT FROM AUTHOR]

During the process of developing commercial chips, the phosphors with single broadband emission are indispensable. In this report, a new ternary phosphate phosphor Na 3 Ba 2 Ca(PO 4) 3 :Eu2+ has been successfully synthesized by the high-temperature solid-state reaction (HSSR) method, which shows broad emitting band in the range of 350–600 nm centered at 436 nm (FWHM ∼ 72.3 nm). The crystal structure of the Na 3 Ba 2 Ca(PO 4) 3 and Eu2+ doped Na 3 Ba 2 Ca(PO 4) 3 were determined by the Rietveld method, indicating the trigonal system with P 31 c space group. The selective two-site occupancy tendency of Eu2+ ions at Ba1O 9 and Ca2O 8 sites in the matrix was comprehensively revealed according to the split peaks (433 nm and 469 nm) at 298 K and 11 K, computational validation and fluorescence lifetime analysis of photoluminescence spectrum. Impressively, the optimal Na 3 Ba 2 Ca(PO 4) 3 :0.02Eu2+ phosphor exhibits appropriate spectrum resemblance (SR) indexes (58.5% and 72.2%), proper thermostability (78.6%) and excellent chromaticity stability (Δ x = 8.68 × 10−6 and Δ y = 3.64 × 10−5). Besides, the phosphor prepared by HSSR owns the higher internal quantum efficiency of 62.1% in comparison with that synthesized by polymerizable complex (PC) method. The new phosphor can serve as a potential broadband and blue-emitting phosphor for the application of solid-state lighting and plant growth. [Display omitted] • First synthesis of Eu2+ ion doped Na 3 Ba 2 Ca(PO 4) 3 phosphor by high temperature solid phase method. • The internal quantum efficiency of phosphor prepared in this work is 9 times of polymerizable complex (PC) method. • Two site-occupancy of Eu2+ in host was carefully determined. • The Na 3 Ba 2 Ca(PO 4) 3 : 0.02Eu2+ owns good thermostability and chromaticity stability. [ABSTRACT FROM AUTHOR]

Upconversion nanoparticles have emerged as promising materials for non-contact temperature sensors due to their unique detection capabilities and low interference, so it is valuable to explore simple and effective approaches to enhance the temperature measurement sensitivity. In this study, we employed a special sol-gel method to prepare NaGd(MoO 4) 2 powder by calcining the precursor mixture, and the fluorescence properties as well as thermal sensitivity were investigated. Analysis based on XRD, SEM and energy transfer modes revealed that the enhancement in temperature sensitivity resulted from the increased distance between the sensitizer and activator ions as well as changes in crystallinity, compared with normal sol-gel method. By optimizing the doping of rare earth ions, the highest sensitivity reached 3.34 %K−1. Additionally, fluorescence spectra analysis of NaGd(MoO 4) 2 samples synthesized via different methods demonstrated that energy transfer between the sensitizer and activator ions can be achieved through high-temperature calcination. Moreover, LiGd(MoO 4) 2 samples prepared using the unique sol-gel method exhibited similar enhancements in temperature sensitivity as NaGd(MoO 4) 2 powder. These findings imply that the samples prepared through the unique sol-gel synthesis method exhibit significant potential in terms of their fluorescence and temperature detection capabilities. [Display omitted] • NaGd(MoO 4) 2 :Er3+-Yb3+ sample was prepared by a special sol-gel method which were calcined after precursor mixing. • The method of calcining after precursor mixing increases the distance between ions and affects crystallinity. • The mixing ratio of the Er3+-Yb3+ doped precursor can be adjusted to achieve higher upconversion. • The temperature sensitivity of the special sol-gel sample prepared in the manuscript is higher, reaching 3.34 %K−1. • Er3+/Yb3+ doped LiGd(MoO 4) 2 prepared by the special sol-gel method also showed similar enhancement in temperature sensitivity. [ABSTRACT FROM AUTHOR]

Ba 0.5 Sr 0.5 TiO 3 –ZnAl 2 O 4 composite ceramics were prepared by double sintering and conventional sintering. The results show that the double sintering can effectively reduce the ion diffusion between Ba 0.5 Sr 0.5 TiO 3 and ZnAl 2 O 4 phases. The double sintered samples exhibit higher density and more uniform grain size distribution than the conventional sintered samples. The dielectric permittivity of double sintered samples is lower than that of conventional sintered samples. Impedance spectrum analysis shows that the oxygen vacancy content and grain boundary resistance of the double sintered samples is lower than that of the conventional sintered samples, which indicates that the Q value of the double sintered samples is higher than that of the conventional sintered samples. The optimum dielectric tunability and Q value of double sintered 60 wt%Ba 0.5 Sr 0.5 TiO 3 -40 wt%ZnAl 2 O 4 sample are 23.4% at 30 kV/cm and 276 at 2.257 GHz, respectively. Therefore, double sintering is a strategy that can effectively adjust the dielectric tunability and Q value of BST-ZA composite ceramics. [ABSTRACT FROM AUTHOR]

An accurate carbon price prediction is vital for governments to formulate emission reduction policies and for corporate managers to carry out sustainable management. Although many models have been proposed to meet this purpose, there is still a lack of comprehensive comparisons among the key competing models in a single study. This study conducted a comprehensive evaluation of six feature selection methods and six machine learning models for carbon price prediction, and then proposed a novel data-driven hybrid model that integrates singular spectrum analysis, random forest, and long short-term memory neural network. The results show that random forest and long short-term memory neural networks are the most competitive feature selection and prediction models, respectively. It is more reasonable to construct the model's input by comprehensively considering variables' short-, medium-, and long-term features. When the recombination value is approximately half the length of the embedding window, the singular spectrum analysis is most conducive to improving the prediction accuracy. The hybrid model proposed is always significantly superior to other benchmark models. Our work contributes to guiding carbon price modeling to help regulators and managers accurately grasp carbon price signals. [ABSTRACT FROM AUTHOR]

Amyloidosis is a deleterious condition caused by abnormal amyloid fibril build-up in living tissues. To date, 42 proteins that are linked to amyloid fibrils have been discovered. Amyloid fibril structure variation can affect the severity, progression rate, or clinical symptoms of amyloidosis. Since amyloid fibril build-up is the primary pathological basis for various neurodegenerative illnesses, characterization of these deadly proteins, particularly utilising optical techniques have been a focus. Spectroscopy techniques provide significant non-invasive platforms for the investigation of the structure and conformation of amyloid fibrils, offering a wide spectrum of analyses ranging from nanometric to micrometric size scales. Even though this area of study has been intensively explored, there still remain aspects of amyloid fibrillization that are not fully known, a matter hindering progress in treating and curing amyloidosis. This review aims to provide recent updates and comprehensive information on optical techniques for metabolic and proteomic characterization of β-pleated amyloid fibrils found in human tissue with thorough literature analysis of publications. Raman spectroscopy and SAXS are well established experimental methods for study of structural properties of biomaterials. With suitable models, they offer extended information for valid proteomic analysis under physiologically relevant conditions. This review points to evidence that despite limitations, these techniques are able to provide for the necessary output and proteomics indication in order to extrapolate the aetiology of amyloid fibrils for reliable diagnostic purposes. Our metabolic database may also contribute to elucidating the nature and function of the amyloid proteome in development and clearance of amyloid diseases. [ABSTRACT FROM AUTHOR]

The precise classification of land covers with hyperspectral imagery (HSI) is a major research-focused topic in remote sensing, especially using unmanned aerial vehicle (UAV) systems as the abundant data sources have brought severe intra-class spectral variability and high spatial heterogeneity challenges, making precise classification difficult. To this end, a novel three-dimensional singular spectrum analysis (3DSSA) method is proposed for the 3D feature extraction of HSI. It aims to construct a low-rank trajectory tensor containing global and local features and extract both spectral discrimination features and spatial contextual features in conjunction with tensor singular value decomposition (t-SVD). To reduce the risk of tensor operations exceeding memory on large-scale HSI data, the extended regional clustering (RC) 3DSSA framework (RC-3DSSA) is proposed for precise HSI classification. RC-3DSSA uses RC processing to alleviate the scale diversity and further applies 3DSSA to tackle issues of intra-class spectral variability and spatial heterogeneity. In order to effectively evaluate the performance of RC-3DSSA, a new challenging classification dataset namely the Qingdao UAV-borne HSI (QUH) dataset was further built. It consists of three sub-datasets: QUH-Tangdaowan, QUH-Qingyun, and QUH-Pingan, which are freely available as benchmarks for precise land cover classification. The experimental results on QUH and two publicly available datasets show that the RC-3DSSA can accurately distinguish ground objects and reliably map their distribution when benchmarked with ten state-of-the-art methods. Specifically, the overall accuracies achieved are 86.62%, 87.51%, and 87.35% under 10% spatially disjoint training samples for the three UAV-borne HSI datasets, respectively, providing the best performance. [ABSTRACT FROM AUTHOR]

• Spectrally resolved DNI was tested for an entire year in Beijing. • The spectra can be represented in five-dimensional data by an autoencoder. • Hierarchical clustering was adopted to obtain ten reference spectra in the case. • Novel local reference spectra can characterize solar resources throughout the year. • The superiority of the new reference spectra over ASTM AM1.5D was verified. The established reference spectrum (ASTM AM1.5) based on mid-latitudes is still the most frequently used standard in design and simulation in various fields worldwide, however, the solar spectrum varies with climate and time, which significantly affects the evaluations of solar energy utilization. This study proposes a novel reference spectrum analysis method to establish several local reference spectra, in this case, based on 147,374 spectra in Beijing, which can characterize solar resources throughout the year. The dataset consists of spectra of direct normal irradiance, and a deep learning autoencoder is adopted to extract the intrinsic features of each spectrum for clustering. 10 clusters are finally divided by agglomerative hierarchical clustering, and 10 local reference spectra were identified from each cluster by correlation analysis. The results show that the shape of new reference spectra shifts to the short wave as the irradiance increases, and the average photon energy increases from 1.069 eV to 1.456 eV. The new local reference spectra are compared with the standard spectrum AM1.5D to show the influence of shape variations, and it reveals 61% maximum differences among photovoltaic applications. The superiority verified new reference spectra could be further used to optimize local solar technologies design and guide photovoltaic material development. [ABSTRACT FROM AUTHOR]

Two series of phosphors of LaSr 1-x GaO 4 :xCr3+ and La 1-x SrGaO 4 :xCr3+were synthesized by a high-temperature solid-state method under the same experimental conditions. The phase structure, surface topography, luminescence properties and luminescence mechanism of phosphors were investigated. LaSrGaO 4 host exhibits a narrow emission band peaks at 716 nm which comes from the intrinsic defects. LaSr 1-x GaO 4 :xCr3+ and La 1-x SrGaO 4 :xCr3+ phosphors show emission spectra with the same shape to the host, while the luminous intensity improved greatly. From the analysis of low temperature spectra and decay lifetimes of the samples, it can be concluded that Cr3+ show no intrinsic luminescence in the LaSrGaO 4 host. The analysis of TL spectra proved that the defect concentration was increased by Cr3+ doping, and enhanced the intrinsic luminescence. The emission spectrum of the LED device based on the LaSr 0.999 GaO 4 :0.001Cr3+ phosphor almost coincides with the absorption spectrum of the P FR phytochrome, which indicated the pc-LED have potential application in the field of plant lighting, especially for the study of the independent regulatory mechanism of P FR. [ABSTRACT FROM AUTHOR]

• This paper presents a solution methodology for the rotor system with bolted joint. • The presented solution methodology is verified by the Newmark method. • The 3X and 5X of the rotating frequency are found in the spectrum. • The rotating speed corresponding to 5X's peak precedes the critical speed. • The findings of spectral characteristics are verfied by the experimental test. The bolted joint is commonly used to connect several parts of aero-engine rotor system. Several papers have studied the nonlinear vibration responses of bolted rotor systems. However, the frequency spectrum characteristics of bolted rotor systems are not fully revealed. Aiming at this issue, this study develops a dynamic model of the bolted rotor system, where the piecewise stiffness characteristic is considered. A solution methodology is presented by incorporating the piecewise stiffness into the incremental harmonic balance method. The effects of unbalance and preload on the dynamic characteristics are discussed. Moreover, the stiffness and damping of the support structure and bolted joint are identified based on the particle swarm optimization algorithm and experimental results. Furthermore, the experimental study on a bolted rotor test rig is conducted to verify the accuracy of the identified parameters and the model. The simulation and experimental results indicate that 3X and 5X of the rotating frequency can be observed. Besides, the rotating speed corresponding to 5X's peak is different from the critical speed, and the peak of 5X precedes the primary resonance peak. [ABSTRACT FROM AUTHOR]

The singular spectrum analysis (SSA) is a relatively new method for decomposing time series into separable and interpretable series (i.e., trend, periodic, and irregular components). Here, the ionospheric variability in the peak electron density (NmF2) observations provided by FORMOSAT-3/Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation measurements during 2009–2019, which completely covers solar-cycle 24, was examined using the nonparametric method (SSA). This study identified different temporal patterns inherent in the COSMIC data, which can be employed to reconstruct/model noise-free time series. Based on a proper choice of SSA parameters, it was observed that SSA can be employed to extract various components of these datasets. Additionally, the results showed that the slowly varying component (trend) was largely influenced by solar activity and closely followed the behavior of the sunspot cycle. The SSA method demonstrated seasonal patterns (the semiannual component). Based on the patterns, the reconstructed series for each of the selected components were separately modeled with a corresponding fit function using the 10.7 cm solar proxy, which prior be smoothed by Spline fitting. It was observed that the polynomial function efficiently modeled the trend component with R2 = 0.95, while the harmonic function adequately represented the semiannual component with R2 = 0.97. To validate the proposed model, the data were estimated for the time interval from January 2020 to August 2022, which represented the ascending phase of the ongoing solar-cycle 25. The results revealed that the modeled data correlated with the observed COSMIC-2 data with a high correlation coefficient (0.95). These findings indicate that the underlying model can effectively describe the behavior of the electron density during the investigated period, and the SSA method is particularly powerful for analyzing nonstationary time series and capable of identifying sub-time series (trends along with seasonal periodic components). [ABSTRACT FROM AUTHOR]

In the present work, a series of Sm3+-doped MO-ZnO-B 2 O 3 –P 2 O 5 (M = Mg, Ca, Sr, Ba) glasses were prepared. The glass structure and luminescence properties were investigated by XRD, DSC, IR, absorption spectroscopy, Judd-Ofelt theory and photoluminescence spectra. The J-O parameters of Sm3+-doped glasses follow the trend of Ω 4 ＞Ω 6 ＞Ω 2. Under the excitation of 401 nm Xenon lamp, Sm3+-doped glasses exhibited four emissions from the transitions of 4G 5/2 →6H J/2 (J = 5, 7, 9, 11) in the visible spectra. The luminous intensity of Sm3+ increases with the asymmetry in local environments and decreases with the increasing radius of the alkaline-earth cation. Among the as-prepared glass, the Sm3+-doped glass containing magnesium oxide exhibits higher values of stimulated emission cross-section (2.18 × 10−21 cm2), gain bandwidth (1.40 × 10−27 cm3), and optical gain (3.83 × 10−24 cm2). All the Sm3+-doped glasses show intense orange light in the CIE 1931 chromaticity diagram with a high color purity exceeding 99%. In addition, the time-resolved emission spectra reveal the decay process of the Sm3+ ions for the transitions 4G 5/2 → 6H 7/2 and 4G 5/2 → 6H 9/2 in the glass containing magnesium oxide. It suggests that Sm3+-doped alkaline-earth zinc borophosphate glasses could be a potential candidate for reddish-orange light-conversion fluorescent materials based on the ultraviolet light-emitting diode. [ABSTRACT FROM AUTHOR]

Raw bioelectrical impedance measurements are often used as a prognosticator of health status because of their association with disease states and malnutrition. Although studies consistently show the effect of physical characteristics on bioelectrical impedance, few investigations describe the effect of race, particularly for Black adults, and many bioelectrical impedance standards were produced from primarily White adults almost 2 decades ago. Therefore, this study sought to evaluate the racial differences in bioelectrical impedance measurements using bioimpedance spectroscopy between non-Hispanic White and non-Hispanic Black adults matched for age, sex, and body mass index. We hypothesized that Black adults would have a lower phase angle from higher resistance and lower reactance compared with White adults. One hundred non-Hispanic White (n = 50) and non-Hispanic Black (n = 50) males (n = 34) and females (n = 66) matched for sex, age, and body mass index completed this cross-sectional study. Participants underwent several anthropometric assessments, including height, weight, waist circumference, hip circumference, bioimpedance spectroscopy, and dual-energy X-ray absorptiometry. Bioelectrical impedance measures of resistance, reactance, phase angle, and impedance were all collected at frequencies of 5, 50, and 250 kHz and bioelectrical impedance vector analysis was performed using 50-kHz data. There were no significant differences for any anthropometric variable between Black and White participants in the total sample or by sex groups. In addition, there were no significant racial differences for any bioelectrical impedance assessment, including bioelectrical impedance vector analysis. Differences in bioelectrical impedance are likely not a function of race between Black and White adults and concerns regarding its utility should not be based on this characteristic. After accounting for all relevant physical attributes known to influence bioelectrical impedance measurements, assessments, including bioimpedance vector analyses, were not significantly different between non-Hispanic Black and White adults. Concerns regarding its utility for Black adults should not be based on race. The absence of race-dependent bioelectrical values may improve clinical confidence and prognostic value in these techniques and limit racial health disparities for Black adults. BMI, body mass index. [Display omitted] [ABSTRACT FROM AUTHOR]

• In contrast to methods such as power spectrum and wavelet analysis, dipole source localization can determine the location and size of activated brain regions during stimulation. • The driver's right intraorbital superior and the infraorbital frontal gyrus regions were significantly activated during visually distracted driving. • The left and right dorsolateral superior frontal gyrus regions were significantly activated during auditory distracted driving. • The right intraorbital superior, infraorbital, and dorsolateral superior frontal gyrus were significantly activated during cognitive distraction. • Driving distracted drivers were most affected in prefrontal cortical regions, especially in the right frontal cortical region. Electroencephalogram (EEG) was used to analyze the differences in brain area activation correlations between driving distraction (visual distraction, auditory distraction, and cognitive distraction) and normal driving. Thirty subjects participated in this study. Three subtasks were designed, which occurred randomly during driving simulation, to investigate the effects of different distractions on the drivers' neural activity. The drivers' right intraorbital superior frontal gyrus and right infraorbital frontal gyrus were significantly activated during visual distraction driving, while the superior frontal gyrus, right dorsolateral region were significantly activated during auditory distracted driving, and the right intraorbital superior frontal gyrus, right infraorbital frontal gyrus and superior frontal gyrus, and right dorsolateral region were significantly activated during cognitive distraction. This intrinsic neural activity in brain regions is expressed through extrinsic driving performance. It was found that auditory distracted driving, with the lowest activation in the right frontal lobe, had the least effect on lateral control of the vehicle, and cognitive distracted driving, with the highest activation in the right frontal lobe, had the greatest effect on lateral control of the vehicle. Therefore, we suggest that prefrontal cortical areas, especially the right frontal cortical area, are most affected by distracted driving. [ABSTRACT FROM AUTHOR]

We analyse how the spectrum of the anisotropic Maxwell system with bounded conductivity σ on a Lipschitz domain Ω is approximated by domain truncation. First we prove a new non-convex enclosure for the spectrum of the Maxwell system, with weak assumptions on the geometry of Ω and none on the behaviour of the coefficients at infinity. We also establish a simple criterion for non-accumulation of eigenvalues at i R as well as resolvent estimates. For asymptotically constant coefficients, we describe the essential spectrum and show that spectral pollution may occur only in the essential numerical range W e (L ∞) ⊂ R of the quadratic pencil L ∞ (ω) = μ ∞ − 1 curl 2 − ω 2 ε ∞ , acting on divergence-free vector fields. Further, every isolated spectral point of the Maxwell system lying outside W e (L ∞) and outside the part of the essential spectrum on i R is approximated by spectral points of the Maxwell system on the truncated domains. Our analysis is based on two new abstract results on the (limiting) essential spectrum of polynomial pencils and triangular block operator matrices, which are of general interest. We believe our strategy of proof could be used to establish domain truncation spectral exactness for more general classes of non-self-adjoint differential operators and systems with non-constant coefficients. [ABSTRACT FROM AUTHOR]

Portable near-infrared (NIR) lighting source stimulates great efforts to exploit NIR phosphor-converted LEDs (pc-LEDs) that push the rapid development of broadband NIR-emitting phosphors. Although Cr3+-activated NIR phosphors designed by multisites occupation strategy show significant potential in emission bandwidth, poor spectral stability caused by different thermal quenching behaviors is a brake on practical application due to different local structure around Cr centers. One-site-based NIR phosphors seem to be an effective method to solve aforementioned problem. Herein, we report a type of new ultra-broadband one-site-based NIR-emitting phosphors NaSc 1-x P 2 O 7 :xCr3+ (NSP:xCr3+) with emission at 910 nm and full width at half maximum (FWHM) of up to ∼200 nm. Their FWHM value exceeds all one-site-based Cr3+-activated phosphors and some multiple-sites ones. Structural analysis and low-temperature spectra demonstrate that such impressive broadband NIR emission originates from Cr3+ occupying at single octahedral Sc site. At 425 K, integrated emission intensity of NSP:0.04Cr3+ phosphor maintains 53.8% of room temperature. A NIR pc-LED prototype is fabricated by using NSP:0.04Cr3+ phosphor with a blue LED chip, and its multipurpose applications in non-destructive detection, night vision and analysis of foodstuff are demonstrated. These findings indicate that broadband NSP:0.04Cr3+ NIR phosphor enabled by one-site occupation strategy has potential prospect for multipurpose NIR pc-LEDs applications. [ABSTRACT FROM AUTHOR]

• Frescoes replicas using red pigments were prepared to develop a smartphone-based methodological approach. • Colour properties were measured by spectrocolorimeter and smartphone. • Chemometric classificatory methods were used to identify red pigments colors. • Low classification errors were obtained employing LDA and SVC classifying methods. • A new and easy approach employing mobile phones to discriminate red pigments is presented. The characterization of red pigments in frescoes wall paintings has been of great interest for researchers to better understand raw material procurement dynamics, pigment receipts, stylistic evolution and to assess their conservation state. In this study a non-destructive colorimetric approach implementing a smartphone-based method was developed in order to be able to distinguish between three pigments made from minium, haematite and cinnabar minerals, and also mixed pigments, preparing frescoes mock-ups following the roman receipt described by Vitruvius. Portable FT-IR, Raman spectroscopy, portable XRF and visible reflectance spectra analyses were carried out as reference methods for smartphone colorimetry results validation. Employing a reference colour sheet to control changing lighting conditions, different chemometric approaches have been developed and tested, cross-referencing standard analytical results with the data obtained by smartphone. Overall, using only colour parameters from the smartphone, a Linear Discriminant Analysis and a Support Vector Classifier were tested to efficiently classify each sample based on the red pigment used, with low prediction errors. This work shows the potential of smartphones as cheap, fast and user-friendly analytical devices for the screening of frescoes, and as a prior selective step before carrying out further more expensive and specialized analyses. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Surgical wound excision is a necessary procedure for burn patients that require the removal of eschar. The extent of excision is currently guided by clinical judgement, with excessinto healthy tissue potentially leading to excessive scar, or inadequate debridement increasing risk of infection. Thus, an objective real-time measure to facilitate accurate excision could support clinical judgement and improve this surgical procedure. This study was designed to investigate the potential use of Rapid evaporative ionisation mass spectrometry (REIMS) as a tool to support data-driven objective tissue excision.Methods: Data were acquired using a multi-platform approach that consisted of both Rapid Evaporative Ionisation Mass Spectrometry (REIMS) performed on intact skin, and comprehensive liquid chromatography-mass spectrometry (LC-MS/MS) lipidomics performed on homogenised skin tissue extracts. Data were analysed using principal components analysis (PCA) and multivariate orthogonal projections to latent squares discriminant analysis (OPLS-DA) and logistic regression to determine the predictability of the models.Results: PCA and OPLS-DA models of the REIMS and LC-MS/MS lipidomics data reported separation of excised and healthy tissue. Molecular fingerprints generated from REIMS analysis of healthy skin tissue revealed a high degree of heterogeneity, however, intra-individual variance was smaller than inter-individual variance. Both platforms indicated high levels of skin classification accuracy. In addition, OPLS-DA of the LC-MS/MS lipidomic data revealed significant differences in specific lipid classes between healthy control and excised skin samples; including lower free fatty acids (FFA), monoacylglycerols (MAG), lysophosphatidylglycerol (LPG) and lysophosphatidylethanolamines (LPE) in excised tissue and higher lactosylceramides (LCER) and cholesterol esters (CE) compared to healthy control tissue.Conclusions: Having established the heterogeneity in the biochemical composition of healthy skin using REIMS and LC-MS/MS, our data show that REIMS has the potential to distinguish between excied and healthy skin tissue samples. This pilot study suggests that REIMS may be an effective tool to support accurate tissue excision during burn surgery. [ABSTRACT FROM AUTHOR]

A detailed analysis of the bremsstrahlung spectrum at nonrelativistic electron scattering on argon and xenon is carried out. It is shown that the approximate formulas widely used for the description of bremsstrahlung spectra lead to predictions that significantly differ from the exact results. In the limit when the photon frequency tends to zero, a rigorous proof of the relationship between the spectrum of the bremsstrahlung with a transport cross section of electron scattering on an atom is given. This proof does not require any assumptions about the dependence of the scattering phases on energy. For electron energies lower than the luminescence threshold, it is shown that the predictions for a number of radiated photons obtained by the exact formula are in good agreement with the available experimental data. [ABSTRACT FROM AUTHOR]

To analyze the effect of PFN content on the microstructure and electrical properties of x Pb(Fe 0.5 Nb 0.5)O 3 –(0.57− x)Pb(Ni 1/3 Nb 2/3)O 3 –0.43Pb(Zr 0.3 Ti 0.7)O 3 , the doping of x PFN–PNN–PZT) were systematically studied with 0.015 ≤ x ≤ 0.075. XRD patterns and Raman spectra analysis reveal that PFN diffuses into PNN–PZT perovskite lattice and forms new quaternary solid solution. With the increase of PFN content x , the proportion of rhombohedral (R) phase decreases gradually, whereas the proportion of tetragonal (T) phase displays a contrary trend. In particular, R – T coexistence near MPB was observed at x = 0.045. Meanwhile, optimized electrical properties of d 33 = 961 pC/N, k p = 0.716, ε r = 6298, and tan δ = 3.1% are achieved for the 0.045PFN–PNN–PZT ceramics. Moreover, the ceramics at MPB showed larger remnant polarization P r = 24.55 μC/cm2, smaller coercive field E c = 0.36 kV/mm, and lower dielectric relaxor degree γ = 1.813. All these results reveal that the enhanced electrical properties could be attributed to synergistic phase boundary motion, dielectric relaxor behavior and ferroelectric hysteresis effect. [ABSTRACT FROM AUTHOR]

Flexible low dielectric constant (low- k) SiCOH thin films were fabricated onto flexible indium tin oxide coated polyethylene naphthalate (ITO/PEN) substrates using plasma-enhanced chemical vapor deposition (PECVD) of a tetrakis(trimethylsilyloxy)silane (TTMSS) precursor. RF plasma powers of 20 and 60 W were utilized for the deposition. The k -values of the pristine SiCOH films deposited at 20 and 60 W were 2.46 and 2.00, respectively. Both films showed hydrophobic surfaces. An inductively coupled plasma-reactive ion etching (ICP-RIE) process was then performed on the flexible SiCOH thin films using CF 4 , CF 4 + O 2 , and CF 4 + Ar. The surface wettability of the films increased substantially following etching, with many of the etched films being considered hydrophilic. The Fourier transform infrared (FTIR) spectra of the pristine films identified four prominent absorption bands as CH x stretching, Si-CH 3 bending, Si-O-Si stretching, and Si-(CH 3) x stretching vibration modes. After the etching process, the peak area ratios of Si-O-Si stretching mode increased and those of Si-(CH 3) x stretching mode decreased. The X-ray photoelectron spectroscopy (XPS) spectra analysis determined significant concentration of fluorine on the surface of the film following etching. From the high-resolution XPS scan, it was found that the peak intensity of the C1s and Si2p peaks decreased after etching process and the peak center of the F1s peak shifted depending on etching chemistry. The k -values of the films at 20 W were fairly consistent while those of the films at 60 W increased significantly following the etching process. The increase in k -value after etching for the films at 60 W correlated with surface hydrophilicity, increase in the refractive index, and change in the peak area ratios of Si-O-Si and Si-(CH 3) x stretching modes in the FTIR spectra. [Display omitted] • Flexible low- k thin films were synthesized by chemical vapor deposition. • Fluorocarbon-based plasma was adopted for etching of flexible low- k films. • Change in chemical structure of flexible low- k films depended on etching chemistry. • Dielectric constant after etching was related to the surface characteristics. [ABSTRACT FROM AUTHOR]

Spectral intensity drift is a frequent issue in analytical processes, especially in long time excitation scanning for large size metal materials, which can significantly adversely impact the accuracy and stability of analysis results. Spectral intensity drift correction is the process of preprocessing spectral data using mathematical algorithms in order to facilitate the subsequent qualitative and quantitative analysis of spectra, especially in combination with stoichiometric methods. Up to now, spectral intensity drift correction within prolonged excitation has not been reported yet. We propose an intensity drift correction method for element content of large-size samples using the Spark Mapping Analysis for Large Samples (SMALS) technique. By considering the row-by-row and column-by-column mapping modes of the SMALS, this includes curve fitting baseline correction for in-row and in-column correction, as well as total average value correction for inter-row and inter-column correction. The final measurement values are derived by coupling rows with columns. The careful implementation of correction steps can enhance baseline correction performance, effectively reducing measurement errors a drift errors. Application of this method to characterize the cross and longitudinal sections of an oversized steel billet indicates high agreement with composition distribution obtained by micro-beam X-ray fluorescence (μ-XRF). The corrected longitudinal and cross-sectional data also exhibit strong alignment. Comparison of statistical analysis results pre- and post-correction demonstrates significant improvements in the clarity of elements segregation pattern. This intensity drift correction method not only enhances the spectral quality but also improves the accuracy and robustness of quantitative and qualitative spectral analysis. This study contributes to establishing a robust foundation for component characterization of large-size metal materials using the SMALS technique. The novel spectral intensity correction method shows theoretical significance and practical value for large-scale, long-duration excitation scanning analysis. [Display omitted] • The measurement error was eliminated by in-row/in-column, inter-row/inter-column correction and complementary coupling. • The intensity drift correction method significantly improves the accuracy and stability of analysis results of the SMALS. • This work laid a firm foundation of component characterization for large-size metal material using the SMALS. [ABSTRACT FROM AUTHOR]

• We proposed a novel method for noise reduction of multichannel heart sound signals, which was based on FastICA algorithm and CNN model. • The method performs classification and consistency analysis of the independent components to extract reliable independent components of heart sounds. • The method improves the SNRs of each channel signal up to 20 dB, which is superior to the Wiener filtering and singular spectrum analysis (SSA). Various noises could contaminate heart sounds and yield inaccurate diagnosis. This paper proposed a framework of heart sound noise reduction using multi-channel structure. Multi-channel heart sound (MCHS) signals were preprocessed, and then decomposed into independent components (ICs) using FastICA algorithm. The ICs were evaluated for consistency using correlation analysis, and reliable ICs were identified. The reliable ICs were classified based on a convolutional neural network (CNN) into two groups: one is of ICs for heart sounds and the other is of ICs for noise, respectively. Consequently, the MCHS signals were reconstructed from the ICs group of heart sounds. To validate the proposed framework, the MCHS signals of 15 subjects were acquired and mixed with breath sounds under different signal-to-noise ratios (SNRs). the simulation results showed that the framework had effective noise reduction performances in suppressing the breath sounds. The SNR of the denoised MCHS could be improved to 20 dB. the proposed framework was better than traditional methods, such as Wiener filter and singular spectrum analysis (SSA). The practical applications proved that the framework is possible to reconstruct the heart sound signals in low signal quality situation. [ABSTRACT FROM AUTHOR]

Herein, six previously undescribed steroids (1–6), were isolated from leaves and twigs of Aphanamixis polystachya (Wall.) R. N. Parker (Meliaceae). Their structures were elucidated by comprehensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR, UV, and IR. Antiviral activity of these compounds were evaluated. Compounds 1–6 showed varying degrees of inhibitory activity against the severe acute respiratory syndrome coronavirus 2 main protease (SARS-CoV-2 Mpro) at 200 μ M. [Display omitted] [ABSTRACT FROM AUTHOR]

Diabetes is a significant global health challenge, affecting circa 540 million adults worldwide. Dioscorea dumetorum , a Nigerian folkloric antidiabetic plant is severely understudied in terms of its bioactive phytochemical constituents. Antidiabetic guided isolation of the tubers and peels of D. dumetorum afforded three phytoecdysteroids bearing a cis -fused A/B ring junction including two new ones: 24-hydroxymuristerone A (1) and 24-hydroxykaladasterone (2), alongside the known muristerone A (3). Additionally, 2,2′,7,7′-tetramethoxy-[1,1′-biphenanthrene]-4,4′,6,6′-tetraol (4), batatasin I (5), and dihydroresveratrol (6) were isolated. Structural elucidation relied on spectroscopic, spectrometric methods, and comparison with existing literature. The ethyl acetate extracts of both the tubers and peels of D. dumetorum exhibited the highest phenolic content, correlating with potent antioxidant activity. Compounds 4 (IC 50 = 0.10 mg/mL) and 6 (IC 50 = 0.22 mg/mL) demonstrated superior inhibitory effects against α-glucosidase compared to acarbose (IC 50 = 0.63 mg/mL). In contrast, compounds 3 , 4 , and 5 showed reduced α-amylase inhibition, with IC 50 values of 2.58, 3.78, and 1.12 mg/mL, respectively, compared to acarbose (IC 50 = 0.42 mg/mL). These observed bioactivities validate the traditional use of D. dumetorum and contribute valuable phytochemical data to the scientific literature of the species. [Display omitted] • Evidence of antidiabetic properties of D. dumetorum is established through a bioactivity-guided fractionation approach. • Two new phytoecdysteroids and the known phytoecdysteroid muristerone A (3) were isolated. • Three known polyphenols were isolated. • Compounds 4 and 6 display higher inhibitory activity against α-glucosidase than the positive control acarbose. • Compounds 4 and 5 display a high antioxidant activity, in the same range as ascorbic acid. [ABSTRACT FROM AUTHOR]

Ligularia fischeri Turcz. is a medicinal plant for the treatment of inflammation in China and Korea. Its chemical components in anti-sepsis activity and the related molecular mechanisms remain unknown yet. In this study, two undescribed eremophilane sesquiterpenoids fischerins A (1) and B (2), together with 8 known sesquiterpenoid derivatives (3 – 10), were isolated from the whole plant of L. fischeri. Their structures were identified by detailed spectroscopic and ECD analyses. 3-Oxo-8-hydroxyeremophila-1,7(11)-dien-12,8-olide (6) showed the most inhibitory effect on NO production in LPS-stimulated RAW 264.7 cells with the IC 50 value of 6.528 μM. Meanwhile, compound 6 also decreased the mRNA expression of pro-inflammatory factors IFN- γ , IL-1 β , IL-6 and TNF- α via downregulating NF-κB signaling pathway in vitro. Furthermore, compound 6 reduced the mortality, murine sepsis score, the serum TNF- α level and organic damage in a mouse model of sepsis. These findings indicated that compound 6 possessed the potent anti-inflammatory activity and had the potential as a promising drug candidate for sepsis therapy. [Display omitted] • Two undescribed eremophilane sesquiterpenoids were isolated from Ligularia fischeri. • Compound 6 showed the anti-inflammatory effect in LPS-induced RAW264.7 cells. • Compound 6 regulated NF-κB pathway in vitro. • Compound 6 showed protective effects against CLP-induced sepsis in vivo. [ABSTRACT FROM AUTHOR]

Three new meroterpenoids (1 – 3) and ten known ones (4 – 13) were obtained from the endophytic fungus Talaromyces primulinus H21 isolated from the plant of Euphorbia sikkimensis. Their structures including their absolute configurations were elucidated by extensive analysis of spectroscopic data such as HR-ESI-MS, 1D/2D NMR, and X-ray diffraction of single crystal together with comparison of experimental ECD with calculated ECD. All compounds were examined for their inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells, and compounds 3 , 9 , 12 , and 13 exhibited certain inhibition on NO production, with IC 50 values of 27.19, 41.55, 25.23, and 24.71 μM, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

In our continuous work on the isolation of endophytes, the endophytic fungal strain YIMF00209 was obtained from the roots of Gmelina arborea , which is an ethnic medicinal plant mainly distributed in Southeast Asia. The fermentation extracts of the strain exhibited significant antimicrobial activities against Staphylococcus aureus , Fusarium solani , and Escherichia coli. Based on morphological characteristics and phylogenetic analysis, it was identified as Talaromyces muroii. Four new polyketides, talaromurolides A-D (1 – 4), along with 26 known compounds (5 – 30), were isolated from the culture broth of the strain in two different media. Their structures were identified based on HRESIMS, NMR, and CD spectral data. Among them, compounds 2 , 4 – 6 , 19 , 22 , 24 , 27 , 28 , and 30 were isolated from the fermentation broth in CYM medium; compounds 1 , 3 , 7 – 18 , 20 , 21 , 23 , 25 , 26 , and 29 were obtained from the fermentation broth in PDB medium; and compounds 2 , 5 , and 30 were existed in both two media. Compounds 6 – 9 , 12 , 16 , 20 , 21 , 23 , 25 , and 29 were obtained from the genus Talaromyces for the first time. The antimicrobial activities of several compounds were assayed against six pathogens. Compound 1 exhibited inhibitory activities against S. aureus , E. coli , Candida albicans , Salmonella typhimurium , and Botrytis cinerea with MIC value of 64 μg/mL. Compound 25 exhibited antibacterial activity against E. coli with MIC value of 32 μg/mL. [Display omitted] [ABSTRACT FROM AUTHOR]

Four previously undescribed sesquiterpenoids (1–4), including two natural guaiane-type sesquiterpenoids (1 – 2), a rearranged guaiane-type sesquiterpenoid (3), and a norsesquiterpenoid (4), were isolated from the ethanol extract of the aerial parts of Pogostemon cablin (Blanco.) Benth. Their chemical structures were determined based on extensive spectroscopic data analysis, including UV, IR, NMR, HRESIMS, and CD spectroscopy. Compound 1 exhibited a good hypoglycemic activity with glucose uptake of 124.3% and 131.2% in myotubes, respectively, at the concentrations of 20 and 40 μM and showed no cytotoxicity. These findings provide a material basis for further research on P. cablin. Four previously undescribed sesquiterpenoids (1–4), including two natural guaiane-type sesquiterpenoids (1 – 2), a rearranged guaiane-type sesquiterpenoid (3), and a norsesquiterpenoid (4), were isolated from the ethanol extract of the aerial parts of Pogostemon cablin (Blanco.) Benth. Compound 1 exhibited a good hypoglycemic activity at the concentrations of 20 and 40 μM and showed no cytotoxicity. [Display omitted] [ABSTRACT FROM AUTHOR]

Three undescribed phenols, mandshusica C-E (1 – 3) and a new lignan, mandshusica F (5), along with six known compounds (4 , 6 – 10) were isolated from the roots and rhizomes of Clematis terniflora var. manshurica (Rupr.) Ohwi. Their structures were elucidated by extensive spectroscopic analysis as well as NMR and ECD calculations. Moreover, the possible biosynthetic pathways of compounds 1 – 3 were also discussed. All compounds were evaluated for their anti-inflammatory activities in LPS-induced RAW 264.7 cells. Compounds 1 , 3 , 4 significantly reduced the levels of NO and TNF-α, while compounds 2 and 8 significantly inhibited NO production in LPS-induced RAW264.7 cells. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A deep learning-based model for the automatic removal of scattering in fluorescence spectra has been developed. • Using the DeepLabV3+ model to segment scattering in three-dimensional fluorescence spectra. • Using GLCIC network to repair fluorescent spectrum of scattering areas. • PARAFAC successfully resolved the component spectra after the model removes scattering. Three-dimensional excitation–emission matrix fluorescence spectroscopy is often plagued by scattering effects, mainly Rayleigh and Raman scattering, and thus must be pre-processed for de-scattering before spectral analysis. In this study, a new method based on deep learning was proposed to automaticly remove the scattering from fluorescence spectra. First, the semantic segmentation model Deeplabv3+ was used to realize the segmentation of the scattering region in the original fluorescence spectrum and compared with other segmentation models. The results show that the mean intersection over union (mIoU) of this model is 89.58 % and its Accuracy is 95.40 %, which are better than those of the other models. Then, the Globally and Locally Consistent Image Completion (GLCIC) network was used to repair the spectral energy of the scattering areas. Model effectiveness in scattering removal is evaluated using metrics such as mean absolute error, mean relative error, structural similarity, and peak signal-to-noise ratio. Furthermore, this study employs PARAFAC for component analysis of the spectra after scattering removal by the model, comparing them with actual components, all yielding correlation coefficients greater than 0.99. The results show that compared with the traditional scattering-removal method based on the mathematical model, the proposed method can automatically remove scattering areas in batch samples' fluorescence spectra, without the need for manual parameter setting or other processes. This improves scattering removal efficiency, enhances the simplicity, and speed of fluorescence detection technology. [ABSTRACT FROM AUTHOR]

• A cascaded high-order tunable multi-wavelength random Raman fiber laser covers 1.1–1.5 μm band is demonstrated. • The effectiveness of the few-mode fiber-based filter on the multi-wavelength random Raman lasing stimulation is investigated. • The method of combination of high-nonlinear dispersion-shifted fiber and standard single-mode fiber to enhance the flatness of the multi-wavelength random lasing is proposed and verified. In recent years, multi-wavelength fiber lasers have become one of the research hotspots and have been extensively applied in optical fiber communication systems. However, the presented multi-wavelength fiber lasers mainly operate in the 1.5 μm band. In this paper, a few-mode fiber filter-based cascaded high-order tunable multi-wavelength random Raman fiber laser (MWRRFL) is demonstrated, for the first time, in which a tuning range covers the 1.1–1.5 μm band. In the half-open MWRRFL, a few-mode fiber-based intermodal interferometer filter is inserted in the point reflector as a wavelength selector. The synergetic effect including high Raman gain and Rayleigh backscattering intensity in the hybrid of dispersion-shifted fiber and standard single-mode fiber is employed. It presents the capability for flat multi-wavelength random lasing stimulation. As a result, the wavelength channel number of the 6th-order random lasing is 6, with a maximum power variation of 4.66 dB and good temporal stability. The proposed cascaded tunable MWRRFL could provide a versatile source for optical fiber communication, optical fiber sensing, spectrum analysis, etc. [ABSTRACT FROM AUTHOR]

This paper explores fractional spectra of signals after two types of nonuniform samplings in the presence of timing offset. Both cases of bandlimited and multiband signals in the fractional Fourier domain are considered, based on which we provide conditions for reconstructing the spectrum and devise relevant methods for compensating the bias introduced by timing offset. To obtain these goals, we divide the nonuniformly sampled signal into uniformly sampled sub-sequences and establish the relationship between the discrete-time fractional Fourier transforms (DTFrFTs) of them and the FrFT of the original signal. It indicates that the obtained DTFrFTs consists of periodic replicas of the FrFT for the original signal with each replica being biased by a phase term introduced by timing offset. Based on the matrix form of the relationship, we implement spectral reconstruction of bandlimited signals under certain conditions by performing the inverse of a matrix determined by the phase terms. Different from bandlimited signals, the DTFrFTs of uniformly sampled sub-sequences for multiband signals are studied within disjoint fractional frequency sub-intervals separated by aliasing boundaries. Moreover, inverse of a matrix with fewer columns and rows is utilized to reconstruct the spectrum. Simulations verify the effectiveness of the proposed methods. • The effect of timing offset in multicoset sampling has been studied in terms of FrFT. • New methods for spectrum analysis have been devised in the presence of timing offset. • The proposed methods have low computational complexity and high accuracy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dy3+, Sm3+ co-activated K 4 Ca(PO 4) 2 phosphors made via Co-precipitation are pure, nano-sized, and suitable for luminescence. • UV excited singly doped ions show peaks transitioned 4F 9/2 →6H 15/2 ,6H 13/2 for Dy3+ and 4G 5/2 →6H 5/2 ,6H 7/2 ,6H 9/2 for Sm3+. • Spectral overlap condition satisfied and Energy transfer occurrence is observed for Dy3+ & Sm3+ ions. • Red deficiency is minimized by substitution of Eu3+ ions as depicted in co-doped emission spectra and CIE. • Applications for warm white emitting nano phosphor may be possible in WLED's, displays and solid-state lightings. Highly luminescent K 4 Ca(PO 4) 2 : RE3+ (RE = Dy3+, Sm3+) materials were synthesized by Co-precipitation method. structural and morphological analysis depicts phase purity and nano structured particles. The study investigated the energy transfer mechanism among dopant ions and examined the impact of concentration on luminescence. Photoluminescence (PL) spectrum analysis revealed that upon near-ultraviolet excitation, K 4 Ca(PO 4) 2 : Dy3+, Sm3+ emission assigned to transitions of different Characteristic peaks observed in region spanning 480 to 650 nm. Furthermore, photometric properties were investigated suggesting synthesized phosphor have application in preparation of white LEDs. [ABSTRACT FROM AUTHOR]

• Hydration damage of conglomerate is jointly controlled by pore and mineralogical factors; • High pore tortuosity directly lead to high hydration damage; • Pores have a greater impact on hydration damage than mineralogical factors. This study endeavors to delve into the microscopic mechanisms of hydration-induced damage in tight conglomerates. Initially, we obtained data on the micro-morphology, elemental composition, and mineral composition of the conglomerate using field emission scanning electron microscopy imaging, EDS energy spectrum analysis, X-ray diffraction mineral experiments, and image fine processing techniques. Subsequently, a conductivity meter was employed to gauge solution conductivity throughout the process, while a high-resolution camera monitored changes in appearance morphology. The hydration samples were then re-examined using field emission scanning electron microscopy imaging and EDS energy spectrum experiments. Our analysis reveals that the extent of hydration-induced damage in the conglomerate samples correlates with their pore and fracture parameter characteristics, as well as their elemental and mineral composition. Notably, samples with higher surface porosity and tortuosity are more susceptible to hydration-induced damage, whereas those with higher circularity, solidity, and degree of orientation of the angle exhibit lower susceptibility. The circumference and aspect ratio display weak positive and negative correlations with the degree of hydration-induced damage in the conglomerate, respectively. However, the detailed mechanism warrants further investigation. Furthermore, samples with elevated montmorillonite content are more prone to hydration-induced damage, whereas those with increased Fe and illite content are less likely to suffer from hydration-induced damage. These findings offer novel insights into the microscopic mechanisms underlying dynamic hydration-induced damage in conglomerate samples and hold significant implications for guiding the efficient development of conglomerate oilfields. [ABSTRACT FROM AUTHOR]

In this paper, we investigate and report the effects of Si4+/Al3+ (SiO 2 /Al 2 O 3) molar concentration ratio on the self-reduction process of Yb3+ to Yb2+ ions and upconversion (UC)-, visible (VIS)- emission spectra, direct optical bandgaps (DOB), indirect optical bandgaps (IOB) of Bin+/Ybm+, Er3+/Bin+, and Er3+/Bin+/Ybm+ (n, m = 3, 2) co-doped SiO 2 –Al 2 O 3 –MgO–TiO 2 (SAMT) magnesium aluminum silicate glasses. The valence states of the bismuth (Bi), and Ytterbium (Yb) elements in the raw materials mixture existing in the SAMT glass were determined using X-ray photoelectron spectroscopy (XPS) spectra analysis. With the increase of Al3+ molar concentration from 16 mol. % up to 20, 24, 28 and 32 mol. % corresponding to the Si4+/Al3+ (SiO 2 /Al 2 O 3) molar concentration ratio of 3.4, 2.5, 1.9, 1.5, and 1.2, the self-reduction process of Yb3+ to Yb2+ ions was enhanced and thus significantly affected the DOB, IOB, the intensities of UC-, VIS- emission spectra of Bin+/Ybm+, Bin+/Er3+, and Bin+/Er3+/Ybm+ (n = 2, 3) co-doped SAMT glasses under excitation of 473 nm, 808 laser diode (LD) and 980 nm LD. In addition, the CIE 1931(x, y) color coordinates for VIS- and UC- emissions spectra of Bin+/Ybm+, Bin+/Er3+ (n = 2, 3) co-doped SAMT under excitation of 473 nm and 808 nm LD are also calculated and determined in the CIE 1931(x, y) chromaticity diagram. • Effect of Si4+/Al3+ ratio on the self-reduction process of Yb3+ to Yb2+ ions were investigated. • XPS results determined existence of Bi3+, Bi2+, Yb3+, and Yb2+ ions in SiO 2 –Al 2 O 3 –MgO–TiO 2 glass. • CIE1931 for VIS, UC emissions of Bin+/Er3+/Ybm + under excitation of 473, 808 nm were determined. [ABSTRACT FROM AUTHOR]

Silicate-Titania (SiTi) glass-ceramics doped with Pr3+ (0.6, 1.6, 2.4 and 3.6 mol%) ions were prepared by sol-gel technique. The materials were characterized by powder XRD, FTIR, TEM, EDX, Optical absorption and Photoluminescence spectroscopy. The identification of non-bridging oxygen (NBO) formation and the removal of OH groups are validated through analysis of the FTIR spectra. Additionally, measurements using XRD and TEM showed that the samples contain nano-sized crystallites. The three phenomenological Judd–Ofelt (J–O) intensity parameters Ω 2 , Ω 4 , and Ω 6 were obtained and used to analyze different radiative characteristics for the fluorescence levels of Pr3+ in the glass ceramic, including radiative lifetime, branching ratio, radiative transition probability and stimulated emission cross-section. Several emissions were observed in the visible region, among which the 1D 2 →3H 4 in the orange-red region is the most intense. All of these reported branching ratios, stimulated emission cross-sections, and visible emission spectra point to the possibility of employing them as red region lasers. The CIE chromaticity coordinates from all of the emission spectra were also assessed to determine if these materials are suitable for orange-red phosphors. According to CIE chromaticity investigations, 1.6 mol% of Pr3+ ion concentration is ideal for SiTiPr glass-ceramic for use as red phosphors and possibly red lasers. • SiO 2 –TiO 2 glass ceramics doped with Pr3+ are synthesized by sol-gel technique. • TiO 2 nanocrystals of size around 10–20 nm are formed. • Judd-Ofelt parameters and radiative parameters are calculated. • Strong emissions in the orange-red region are observed under blue excitation. • Cross-relaxation reduces luminescence at high Pr3+ concentration. [ABSTRACT FROM AUTHOR]

We propose an alternative method for processing infrared thermography (IRT) data based on a thermal 1-layer model. The method is based on the analogy of the Shock Response Spectrum (SRS) analysis for mechanical systems (ISO 18431). A thermal Q-factor, similar to the resonance sharpness (Q-factor) of a mechanical oscillator, is introduced as a parameter for selecting a specific thermal 1-layer model. Two main aspects of this method and corresponding properties have been considered: the strictly model-based treatment of this methodology and an empirical introduction of additional bandpass filters. The method is validated with two practical examples: for a homogeneous polymer sheet with blind holes and an inhomogeneous plate made of carbon fiber reinforced polymer (CFRP) with artificial defects, the capability of defect detection is compared with established methods. The comparison of the results with the commonly used data processing methods of IRT as Pulsed Phase Thermography (PPT) and Modified Differential Absolute Contrast (MDAC) shows equivalent or sometimes improved performance. [ABSTRACT FROM AUTHOR]