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An algorithm for solving exciton Schrodinger equation in an arbitrary 2D multiple quantum well structure under applied electric field is proposed, allowing one to model both the absorption and refraction spectra consistently and efficiently. It gives much better quantitative results than variational approximation, while being faster than more advanced methods. The algorithm is implemented using R language and tested by comparing to other published results. Possible improvements are discussed.

Four oxovanadium (IV) complexes with different ligands have been prepared and characterized by different spectral techniques such as (FTIR, UV–Vis., Mass) spectra, magnetic susceptibility, and DFT theoretical studies. Ligands used in this study were 8-hydroxyquinoline (HQ), oxalate (ox), dithiooximid (DTO), and 3-aminopyridine (APY). All the spectroscopic data and the theoretical calculations confirmed that the oxovanadium (IV) complexes are paramagnetic and have distorted square pyramidal structures. The FTIR spectra explain that the ligands were bidentate by (N, O), (O, O), (N, N) ligands, and monodentate (N-donor) 3-aminopyridine ligand. The mass spectral data confirmed that the complexes are mononuclear. Theoretical calculations of the free ligands and the prepared complexes have been done by using DFT calculations with proper basis sets for each other. The complexes were very stable and their energies ranged from (−775.86 to −1164.09 a.u.) and were very different from that of the free (HQ, ox, DTO and APY) ligands. The prepared complexes are more polar (5.69 to 15.54 Debye) than the free ligands. The HOMO orbitals energies of the complexes are ranged from (−0.098 to −0.392 a.u.), whereas the ligands are ranged from (−0.216 to −0.262 a.u.), and the LUMO orbitals energies of the oxocomplexes are ranged from (−0.007 to −0.296 a.u.)

45P2O5-15BaO-25ZnO-15B2O3 glasses doped with different concentrations (0, 0.1, 0.25, 0.5, and 0.75 mol%) of Gd3+ were prepared by a melt-quenching method and treated to fabricate glass-ceramics containing BaZn2(PO4)2 crystals by controllable crystallization. The structural, optical, and dosimetric properties were investigated. FTIR spectra indicates the glasses were composed of [PO4], [BO3], and [BO4] basic structural units. The XRD pattern analysis indicated the samples contained BaZn2(PO4)2 crystals. In the photoluminescence (PL) spectra, two emission bands were observed at 307 and 313 nm due to the 6P5/2→8S7/2 and 6P7/2→8S7/2 transitions of Gd3+, respectively. The OSL dosimetric properties of glass-ceramics were studied further under beta radiation of 90Sr. The optimal Gd3+ doping concentration of 0.5 mol% was determined. The fading of the OSL signal shows that the CW-OSL signal of Gd3+-doped BaZn2(PO4)2 glass-ceramics decays by about 58.95% within 120 h, and the intensity remains stable thereafter. The thermoluminescence (TL) curve has three peaks at 164, 240, and 344 °C. Minimum detectable dose (MDD) of the 0.5 mol% Gd3+-doped BaZn2(PO4)2 glass-ceramics was calculated as 0.675 mGy. The samples also exhibit good signal reusability and a broad linear dose-response range (0.3–500 Gy). Results show the excellent dosimetric properties of Gd3+-doped BaZn2(PO4)2 glass-ceramics and their potential application in radiation dosimetry.

Mesospheric gravity-wave (GW) phase velocity spectra and total powers at two Antarctic stations, Davis and Syowa, were derived using OH airglow image data from March to October in 2016. The total p...

We developed bright yellow-emitting long persistent luminescence (LPL) materials Sr4Al14O25:Mn2+ and Sr4Al14O25:Mn2+,N (N = Zr4+, Ho3+, Er3+) by high temperature solid-state reaction. The addition of Zr4+, Ho3+ and Er3+ can regulate trap distributions and improve energy storage ability of the materials. The LPL performance of SAO:Mn2+,Ho3+ is optimal, considering LPL intensity and duration time. Bright LPL of SAO:Mn2+,Ho3+ can be observed for 3 h by naked eyes in dark after removing the excitation source. Profiles of LPL spectra are different from those of PL, because the two types of Mn2+ centers do not play equal parts in LPL and PL. Trap depths of TL peaks centered at 354 K (peak 1) and 455 K (peak 2) are 0.60 and 0.72 eV, respectively. And peak 1 at 354 K is the effective TL peak responsible for LPL. In SAO:Mn2+,Ho3+, Mn2+ ions doped in Al3+ sites serve as emitting centers, and positively charged Ho Sr · defects are the main effective trap centers. Finally, a feasible LPL mechanism of SAO:Mn2+,Ho3+ was proposed to clarify the generation process of LPL.

Developing dual-state luminophores (DSLs) with strong fluorescence in both the monomer and aggregate states is urgently needed but remains a huge challenge because most current luminophores are eit...

Older bridges are often not adequately designed for earthquakes. To enable a structural verification, new methods such as conditional spectra and conditional mean spectra have been developed to estimate seismic hazards more accurately. To quantify the advantage of the latter method for regions with low and moderate seismic hazards, the seismic internal forces of four Swiss existing bridges were calculated and compared based on conditional mean spectra and uniform hazard spectra. The examples chosen were two reinforced concrete and two steel bridges, one of which was used for road traffic and one for railway traffic. The bridge selection was intended to show the validity of the results for different bridge types. On average, the computations using conditional mean spectra showed lower internal forces than when using uniform hazard spectra. However, the difference was smaller than expected. In addition, practical application in an engineering office would be very time-consuming with today's software solutions. Nevertheless, the results also showed that the differences at component level can be significant.

As reported in the literature, the doping of L,α-alanine (LA) led to increasing the phase transition temperature in triglycine sulfate (TGS) – a bio-ferroelectric material that has been widely applied in industry. The nature of this anomaly is commonly investigated by considerably complicated theoretical and experimental techniques. Unlike previous studies, the present work proposes a simple physical method of analyzing frequency spectra for dielectric loss to clarify the relationship between the movement of phase transition positions and the shift of relaxation frequencies observed in the spectra. The experimental results obtained for LA-doped TGS samples synthesized at different LA contents (0, 5, 10, 20, and 30 wt.%) were used for the analysis. It was indicated that the increase in phase transition temperature was accompanied by the decrease in relaxation frequencies due to the enhanced viscosity created by strong hydrogen bonds formed between amino acids of alanine and TGS structure.

This paper investigates the algorithmic dimension spectra of lines in the Euclidean plane. Given any line L with slope a and vertical intercept b, the dimension spectrum sp ( L ) is the set of all effective Hausdorff dimensions of individual points on L. We draw on Kolmogorov complexity and geometrical arguments to show that if the effective Hausdorff dimension dim ( a , b ) is equal to the effective packing dimension Dim ( a , b ), then sp ( L ) contains a unit interval. We also show that, if the dimension dim ( a , b ) is at least one, then sp ( L ) is infinite. Together with previous work, this implies that the dimension spectrum of any line is infinite.

Fourier-transform infrared spectroscopy (FTIR) is a widely adopted technique for characterizing the chemical composition in many physical and chemical analyses. However, FTIR spectra are subject to multiple sources of uncertainty, and thus the analysis of them relies on domain experts and can only lead to qualitative conclusions. This study aims to analyze the effect of a certain treatment on FTIR spectra subject to two commonly observed uncertainties, the offset shift and the multiplicative error. Due to these uncertainties, the pre-exposure FTIR spectra are modeled according to the physical understanding of the uncertainty--observed spectra can be viewed as translating and stretchering an underlying template signal, and the post-exposure FTIR spectra are modeled as the translated and stretchered template signal plus an extra functional treatment effect. To provide engineering interpretation, the treatment effect is modeled as the product of the pattern of modification and its corresponding magnitude. A two-step parameter estimation algorithm is developed to estimate the underlying template signal, the pattern of modification, and the magnitude of modification at various treatment strengths. The effectiveness of the proposed method is validated in a simulation study. Furtherly, in a real case study, the proposed method is used to investigate the effect of plasma exposure on the FTIR spectra. As a result, the proposed method effectively identifies the pattern of modification under uncertainties in the manufacturing environment, which matches the knowledge of the affected chemical components by the plasma treatment. And the recovered magnitude of modification provides guidance in selecting the control parameter of the plasma treatment.

In this study, a diamond-based neutron scatter camera (DNSC) was developed for neutron spectroscopy in high flux environments. The DNSC was evaluated experimentally and through simulations. It was simulated using several Monte Carlo codes in a two-array layout. The two-array model included two diamond detectors. The simulation reconstructed the spectra of 252Cf and 239Pu–Be neutron sources with high accuracy (∼93%). The two-diamond array system was experimentally evaluated, demonstrating the neutron spectroscopy capabilities of the DNSC. The reconstructed spectrum of the 239Pu–Be source manifested the characteristic peaks of the source. The advantage of a DNSC over a NSC is its ability to define any neutron double-scattering events without the need to absorb incident neutrons in the second detector, and atomic recoil energy information is not needed to determine the incident neutron energy.

We provide a complete description of the spectrum and the essential spectra of weighted composition operators T = w T φ on C ( K ) in the case when the map φ is a non-invertible homeomorphism of K into itself.

The aerodynamic heating experienced by capsules entering into the atmospheres of Saturn, Uranus, and Neptune is greatly affected by chemically non-equilibrium processes occurring in the shock layers. There are two orders of magnitude discrepancies among reaction schemes used in numerical predictions for hydrogen dissociation and ionization, and it is not yet known which set of reaction schemes would predict these entry conditions more accurately. This paper reports the results of electron number density measurements conducted in the X2 expansion tube at the University of Queensland using a condition representative of a proposed Saturn entry where a significant non-equilibrium shock layer is expected. Electron number density along the stagnation streamline was obtained from Stark broadening by deconvolving the measured H-beta spectral line width obtained from the contributions of other dominant broadening mechanisms. The data presented here provides an independent measurements for evaluating the reaction schemes for the conditions created. It was found that the experimental data were well modeled by contemporary kinetic models. Quantitative agreement between experimental and numerical data was found by adjusting the ionization rate coefficients from an existing reaction scheme by a factor of 25.

The luminescent characteristics of spherical hafnia/silica (HfO2/SiO2) nanoparticles (NPʼs) co-doped with Tb3+/Yb3+ were analysed. These NPʼs were synthesized using the spray pyrolysis technique. The addition of SiO2 and Tb3+/Yb3+ was found to induce a cubic phase in HfO2. The luminescent spectra presented the characteristic emission peaks for inter-electronic energy levels transitions of the Tb3+ and Yb3+ ions, with an excitation band centred at 270 nm. Under solid-state laser excitation at 980 nm an upconversion emission related to the Tb3+ ion was observed. The maximum emission peak in the visible region was at 543 nm, associated with 5D4 → 7F5 transitions of the Tb3+ ions and an IR emission peak at 970 nm (2F5/2 → 2F7/2) pertaining to Yb3+, with irradiation at 270 nm (UV). The energy transfer mechanism from Tb3+→Yb3+ (excitation at 270 nm), is discussed based on the time decay of the luminescence intensity analysis and the energy transfer efficiency (ηET) and was determined to be in the range of 29.2%–40.8%.

In a study to provide ground truth data for mid infrared observations of the surface of Mercury with the MERTIS (Mercury Radiometer and Thermal Infrared Spectrometer) instrument onboard the ESA/JAXA BepiColombo mission, we have studied 17 synthetic glasses. These samples have the chemical compositions of characteristic Hermean surface areas based on MESSENGER data. The samples have been characterized using optical microscopy, EMPA and Raman spectroscopy. Mid infrared spectra have been obtained from polished thin sections using Micro FTIR, and of powdered size fractions of bulk material (0-25, 25-63, 93-125 and 125-250 micron) in the 2.5 to 18 micron range. The synthetic glasses display mostly spectra typical for amorphous materials with a dominating, single Reststrahlen Band (RB) at 9.5 micron to 10.7 micron. RB Features of crystalline forsterite are found in some cases at 9.5 to 10.2 micron, 10.4 to 11.2 micron, and at 11.9 micron. Dendritic crystallization starts at a MgO content higher than 23 wt.% MgO. The Reststrahlen Bands, Christiansen Features (CF), and Transparency Features (TF) shift depending on the SiO2 and MgO contents. Also a shift of the Christiansen Feature of the glasses compared with the SCFM (SiO2/(SiO2+CaO+FeO+MgO)) index is observed. This shift could potentially help distinguish crystalline and amorphous material in remote sensing data. A comparison between the degree of polymerization of the glass and the width of the characteristic strong silicate feature shows a weak positive correlation. A comparison with a high-quality mid-IR spectrum of Mercury shows some moderate similarity to the results of this study, but does not explain all features.

Using wide-band (0.5-6.5 eV) spectroscopic ellipsometry we study ultrathin [Bi(0.6-2.5 nm)-FeNi(0.8,1.2 nm)]N multilayer films grown by rf sputtering deposition, where the FeNi layer has a nanoisland structure and its morphology and magnetic properties change with decreasing the nominal layer thickness. From the multilayer model simulations of the ellipsometric angles, Psi(omega) and Delta(omega), the complex (pseudo)dielectric function spectra of the Bi layer were extracted. The obtained results demonstrate that the Bi layer can possess the surface metallic conductivity, which is strongly affected by the morphology and magnetic properties of the nanoisland FeNi layer in the GMR-type Bi-FeNi multilayer structures., 6 pages, 4 figures

In order to provide spectral ground truth data for remote sensing applications, we have measured mid-infrared spectra (2–18 µm) of three typical, well-defined lithologies from the Chelyabinsk meteorite that fell on February 15, 2013, near the city of Chelyabinsk, southern Urals, Russia. These lithologies are classified as (a) moderately shocked, light lithology, (b) shock-darkened lithology, and (c) impact melt lithology. Analyses were made from bulk material in four size fractions (0–25 µm, 25–63 µm, 63–125 µm, and 125–250 µm), and from additional thin sections. Characteristic infrared features in the powdered bulk material of the moderately shocked, light lithology, dominated by olivine, pyroxene and feldspathic glass, are a Christiansen feature (CF) between 8.5 and 8.8 µm; a transparency feature (TF) in the finest size fraction at ∼13 µm, and strong reststrahlen bands (RB) at ∼9.1 µm, 9.5 µm, 10.3 µm, 10.8 µm, 11.2–11.3 µm, 12 µm, and between 16 and 17 µm. The ranges of spectral features for the micro-FTIR spots show a wider range than those obtained in diffuse reflectance, but are generally similar. With increasing influence of impact shock from ‘pristine’ LL5 (or LL6) material (which have a low or moderate degree of shock) to the shock-darkened lithology and the impact melt lithology as endmembers, we observe the fading/disappearing of spectral features. Most prominent is the loss of a ‘twin peak’ feature between 10.8 and 11.3 µm, which turns into a single peak. In addition, in the ‘pure’ impact melt “endmember lithology” features at ∼9.6 µm and ∼9.1 µm are also lost. These losses are most likely correlated with decreasing amounts of crystal structure as the degree of shock melting increases. These changes could connect mid-infrared features with stages for shock metamorphism (Stoffler et al., 1991): Changes up to shock stage S4 would be minor, the shock darkened lithology could represent S5 and the impact melt lithology S6 and higher. Similarities of the Chelyabinsk spectra to those of other LL chondrites indicate that the findings of this study could be related to this group of meteorites in general.

In this paper, we present data from the Blind Ultra-Deep H i Environmental Survey (BUDHiES), which is a blind 21-cm H i spectral line imaging survey undertaken with the Westerbork Synthesis Radio Telescope. Two volumes were surveyed, each with a single pointing and covering a redshift range of 0.164 < z < 0.224. Within these two volumes, this survey targeted the clusters Abell 963 and Abell 2192, which are dynamically different and offer unique environments to study the process of galaxy evolution within clusters. With an integration time of 117 × 12 h on Abell 963 and 72 × 12 h on Abell 2192, a total of 166 galaxies were detected and imaged in H i. While the clusters themselves occupy only 4 per cent of the 73 400 Mpc3 surveyed by BUDHiES, most of the volume consists of large-scale structures in which the clusters are embedded, including foreground and background overdensities and voids. We present the data processing and source detection techniques and counterpart identification based on a wide-field optical imaging survey using the Isaac Newton Telescope and deep ultraviolet (UV) Galaxy Evolution Explorer (GALEX) imaging. Finally, we present H i and optical catalogues of the detected sources as well as atlases of their global H i properties, which include integrated column density maps, position–velocity diagrams, global H i profiles, and optical and UV images of the H i sources.

In this work, electron paramagnetic resonance (EPR) spectra of gamma irradited L-proline and L-serine powders have been examinated at 300 K, as well as to determine their stability and radical structures. The EPR of samples were attributed to the CH3ĊH and CH2ĊNH2 radicals. The EPR spectra were seen to be stable for more than five months. The results obtained from the radicals discussed here were observed to be in good agreement with the literature data.

The acoustic emission (AE) technique has played a critical role in characterizing the fracturing process during laboratory rock mechanics experiments. However, this method is limited by low signal-to-noise ratio (S/N) because of significant noise in the measurement and environment and inaccurate AE location. Furthermore, it is difficult to distinguish two or more hits because their arrival times are very close when AE signals are mixed with strong background noise. Thus, we have developed a new method for detecting weak AE signals using the mathematical morphology (MM) character correlation of the time-frequency spectrum. The character in all hits of an AE event can be extracted from time-frequency spectra based on the theory of MM. Through synthetic and real data experiments, we determined that this method accurately identifies weak AE signals. Compared with conventional methods, our approach can detect AE signals with a lower S/N.

Purpose: To compare the light transmittance property of seven currently used intraocular lens (IOL) models by spectrophotometer data.Methods: Light transmission spectra of seven IOL models were assessed with a spectrophotometer. The transmittance properties were analyzed in 1 nm units from 350 nm wavelength to 800 nm.Results: Three ultraviolet filtering IOL models (ZCB00, XC1-SP, and AT LISA 809M) showed nearly full transmittance of the light from 400 to 500 nm, while steeply attenuating light with shorter wavelengths in various degrees. Three blue-light filtering IOLs (yellow-tinted IOLs; XY1, SN60WF, and TNFT00) showed a slow-sloped increase of light transmission between 400 to 500nm. Among the three, XY1 showed different degree of inclination, showing a steeper slope than SN60WF and TNFT00. The violet-light filtering IOL (ZFR00V) showed a rapid increase of the transmission at around 435 nm wavelength, which is similar to ultraviolet filtering IOLs.Conclusions: The seven different IOLs measured showed different characteristics of light transmission depending on the properties of each material and color. Blue-light filtering IOLs tend to blocked a wide range of wavelength up to 500 nm, but rather were not effective at the range of 400 to 430 nm. Violet-light filtering IOL showed advantages in filtering the high-energy wavelength, around 430 nm, having a potential risk to retina and allowing the transmission of useful blue and green wavelength which is necessary for a better scotopic contrast sensitivity.

In the work, CdSxSe1-x/N-GQDs composites were fabricated via a simple one-step hydrothermal process and their tunable composition, structure and photoelectric properties were characterized by various techniques. The photoelectric properties of CdSxSe1-x/N-GQDs could be adjusted by different Se/S ratios and tunable band-gaps. CdSxSe1-x/N-GQDs composites reached the optimal photocurrent response and the lowest interfacial impedance at the Se/S ratio of 0.75:0.25. Mott-Schottky plots and LSV spectra showed that the n-type CdS0.25Se0.75/N-GQDs presented a higher carrier density under light illumination. The excellent properties of the composites could be attributed to the mechanism involved in the excitation and electron-transfer process. On one hand, the band-gap of CdS0.25Se0.75/N-GQDs was narrowed, and more electrons were excited by the lower band-gap energy to promote a superior electron separation and transportation. On the other hand, N-GQDs acted as charge carriers and conductive way providers for electron-transfer instead of electron-hole recombination in the composites.

NMR spectra acquired with experiments using frequency-sweeps such as the wide-band uniform-rate smooth truncation (WURST) spin-echo and Carr-Purcell-Meiboom-Gill (CPMG) sequences cannot be absorptively phased by using only conventional zeroth- and first-order phase correction. Implementation of phase correction up to the second-order is described for obtaining absorptive spectra, which have more desirable line shapes and noise properties than magnitude spectra. The relationship of the second-order phase to the parameters of frequency sweeps is derived. The second-order phasing in the frequency-domain is equivalent to a point spread in the time-domain signal. The application of second-order phase correction is demonstrated with a wideline 35Cl CPMG spikelet spectrum.

Here, we report on the Fano resonance characteristics tunability in a coupled system of magnonic stripes and resonators by variation the geometric parameters, the magnitude of the coupling between them, and the intensity of spin waves. Using numerical integration of the coupled wave equation system, we calculated the transfer characteristics of the considered system and the parameters of Fano resonance taking into account the cubic nonlinearity of magnetic media. We demonstrate the features of constructive and destructive interference of spin waves at Fano resonance. Our results reveals the mechanism of the spin-wave spectra control of the nonlinear Fano resonance (asymmetry coefficient, resonance frequency shifts) via the intensity of spin wave.

The changes in the crystallographic parameters of Y0.79-zAlzYb0.18Er0.03NbO4 powders prepared with varying Al content were determined by Rietveld refinement, and their effects on the up- (UC) and down-conversion (DC) spectra were studied. The findings confirmed that the Al3+, Yb3+, and Er3+ ions were completely incorporated at the Y3+ sites. The substitution of the small Al3+ ions led to the modification of the interatomic distance. As a result, the highest polyhedral distortion index of the YO8 dodecahedron (DYO) could be achieved at z = 0.2. Under infrared radiation, UC spectra demonstrated that a two-photon energy transfer (ET) UC process from Yb3+ to Er3+ was responsible for the green and red emissions, whose intensities increased dramatically by 160 and 166% at z = 0.2, respectively. This enhancement was a consequence of a large crystal-field asymmetry surrounding the Yb3+ and Er3+ ions, which resulted from the highest DYO at z = 0.2. In addition to D, the Yb‒Er interatomic distance was responsible for the enhanced UC emission, affecting the ET probability from Yb3+ to Er3+. Under 379 nm excitation, the DC green emission of Er3+ also showed the maximal intensity at z = 0.2 owing to the largest DYO. However, a correlation between the crystallographic variations and the DC emissions activated by [NbO4]3- niobates could not be fully elucidated owing to the complexity of the emission mechanism.