Isotope shifts in the [10.1]4–X4 (0–0) and [10.5]3–X4 (0–0) transitions of NdOThis article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.

2009 ◽  
Vol 87 (5) ◽  
pp. 537-541 ◽  
Author(s):  
Alain Bernard ◽  
Amanda J. Ross
Keyword(s):  
Near Infrared ◽  
Thermal Emission ◽  
Emission Spectra ◽  
Spectroscopic Constants ◽  
Isotopic Shifts ◽  
Oppenheimer Approximation ◽  
Global Fit ◽  
Atomic Lines ◽  
The University ◽  
Line Positions

High-resolution Fourier transform thermal emission spectra of NdO (natural isotopic composition) have been recorded in the near infrared. Rotational analyses of the 0–0 band of the [10.132]4–X(1)4 system have been performed for all seven isotopomers, and the 0–0 band of the [10.506]3–X(1)4 system has been analysed for 142NdO, 144NdO, and 146NdO. Experimental data have been merged into a global fit to obtain a unique set of isotopically consistent rotational spectroscopic constants, scaled to 142NdO by assuming isotopic relationships within the Born–Oppenheimer approximation, but with independent band origins. These vibronic energy shifts reflect the isotopic shifts observed in some atomic lines also seen in the spectrum. A catalogue of experimental line positions and o−c values is available as Supplementary data.

scholarly journals Upconversion Luminescence of Silica–Calcia Nanoparticles Co-doped with Tm3+ and Yb3+ Ions

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 937
Author(s):  
Katarzyna Halubek-Gluchowska ◽  
Damian Szymański ◽  
Thi Ngoc Lam Tran ◽  
Maurizio Ferrari ◽  
Anna Lukowiak
Keyword(s):  
Energy Transfer ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Sol Gel ◽  
Emission Spectra ◽  
Transmission Electron ◽  
Characteristic Emission ◽  
Diffraction Patterns ◽  
Size Of Particles ◽  
Average Size

Looking for upconverting biocompatible nanoparticles, we have prepared by the sol–gel method, silica–calcia glass nanopowders doped with different concentration of Tm3+ and Yb3+ ions (Tm3+ from 0.15 mol% up to 0.5 mol% and Yb3+ from 1 mol% up to 4 mol%) and characterized their structure, morphology, and optical properties. X-ray diffraction patterns indicated an amorphous phase of the silica-based glass with partial crystallization of samples with a higher content of lanthanides ions. Transmission electron microscopy images showed that the average size of particles decreased with increasing lanthanides content. The upconversion (UC) emission spectra and fluorescence lifetimes were registered under near infrared excitation (980 nm) at room temperature to study the energy transfer between Yb3+ and Tm3+ at various active ions concentrations. Characteristic emission bands of Tm3+ ions in the range of 350 nm to 850 nm were observed. To understand the mechanism of Yb3+–Tm3+ UC energy transfer in the SiO2–CaO powders, the kinetics of luminescence decays were studied.

Optical Properties and Zinc Nitride Thin Films Prepared Using Magnetron Reactive Sputtering

2014 ◽  
Vol 940 ◽  
pp. 11-15
Author(s):  
Jun Qin Feng ◽  
Jun Fang Chen
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Sem Images ◽  
Fluorescence Emission Spectra ◽  
Glass Substrates ◽  
Zinc Nitride ◽  
Direct Band

Zinc nitride films were deposited by ion sources-assisted magnetron sputtering with the use of Zn target (99.99% purity) on 7059 glass substrates. The films were characterized by XRD, SEM and EDS, the results of which show that the polycrystalline zinc nitride thin film can be grown on the glass substrates, the EDS spectrum confirmed the chemical composition of the films and the SEM images revealed that the zinc nitride thin films have a dense structure. Ultraviolet-visible-near infrared spectrophotometer was used to study the transmittance behaviors of zinc nitride thin films, which calculated the optical band gap by Davis Mott model. The results of the fluorescence emission spectra show the zinc nitride would be a direct band gap semiconductor material.

scholarly journals Shoreline Changes along Northern Ibaraki Coast after the Great East Japan Earthquake of 2011

2021 ◽  
Vol 13 (7) ◽  
pp. 1399
Author(s):  
Quang Nguyen Hao ◽  
Satoshi Takewaka
Keyword(s):  
Near Infrared ◽  
Thermal Emission ◽  
Sandy Beaches ◽  
Great East Japan Earthquake ◽  
Shoreline Changes ◽  
Run Up ◽  
Tsunami Run Up ◽  
Sentinel 2 ◽  
Infrared Radiometer

In this study, we analyze the influence of the Great East Japan Earthquake, which occurred on 11 March 2011, on the shoreline of the northern Ibaraki Coast. After the earthquake, the area experienced subsidence of approximately 0.4 m. Shoreline changes at eight sandy beaches along the coast are estimated using various satellite images, including the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), ALOS AVNIR-2 (Advanced Land Observing Satellite, Advanced Visible and Near-infrared Radiometer type 2), and Sentinel-2 (a multispectral sensor). Before the earthquake (for the period March 2001–January 2011), even though fluctuations in the shoreline position were observed, shorelines were quite stable, with the averaged change rates in the range of ±1.5 m/year. The shoreline suddenly retreated due to the earthquake by 20–40 m. Generally, the amount of retreat shows a strong correlation with the amount of land subsidence caused by the earthquake, and a moderate correlation with tsunami run-up height. The ground started to uplift gradually after the sudden subsidence, and shoreline positions advanced accordingly. The recovery speed of the beaches varied from +2.6 m/year to +6.6 m/year, depending on the beach conditions.

scholarly journals NEAR-INFRARED THERMAL EMISSION DETECTIONS OF A NUMBER OF HOT JUPITERS AND THE SYSTEMATICS OF GROUND-BASED NEAR-INFRARED PHOTOMETRY

2015 ◽  
Vol 802 (1) ◽  
pp. 28 ◽  
Author(s):  
Bryce Croll ◽  
Loic Albert ◽  
Ray Jayawardhana ◽  
Michael Cushing ◽  
Claire Moutou ◽  
...  
Keyword(s):  
Near Infrared ◽  
Thermal Emission ◽  
Infrared Photometry ◽  
Hot Jupiters

scholarly journals A Novel Index for Impervious Surface Area Mapping: Development and Validation

2018 ◽  
Vol 10 (10) ◽  
pp. 1521 ◽  
Author(s):  
Yugang Tian ◽  
Hui Chen ◽  
Qingju Song ◽  
Kun Zheng
Keyword(s):  
Near Infrared ◽  
Thermal Emission ◽  
Impervious Surface ◽  
Urban Heat Islands ◽  
Landsat 8 ◽  
Remotely Sensed Data ◽  
Capital Cities ◽  
Heat Islands ◽  
Surface Areas ◽  
Hydrological Cycles

The distribution and dynamic changes in impervious surface areas (ISAs) are crucial to understanding urbanization and its impact on urban heat islands, earth surface energy balance, hydrological cycles, and biodiversity. Remotely sensed data play an essential role in ISA mapping, and numerous methods have been developed and successfully applied for ISA extraction. However, the heterogeneity of ISA spectra and the high similarity of the spectra between ISA and soil have not been effectively addressed. In this study, we selected data from the US Geological Survey (USGS) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) spectral libraries as samples and used blue and near-infrared bands as characteristic bands based on spectral analysis to propose a novel index, the perpendicular impervious surface index (PISI). Landsat 8 operational land imager data in four provincial capital cities of China (Wuhan, Shenyang, Guangzhou, and Xining) were selected as test data to examine the performance of the proposed PISI in four different environments. Threshold analysis results show that there is a significant positive correlation between PISI and the proportion of ISA, and threshold can be adjusted according to different needs with different accuracy. Furthermore, comparative analyses, which involved separability analysis and extraction precision analysis, were conducted among PISI, biophysical composition index (BCI), and normalized difference built-up index (NDBI). Results indicate that PISI is more accurate and has better separability for ISA and soil as well as ISA and vegetation in the ISA extraction than the BCI and NDBI under different conditions. The accuracy of PISI in the four cities is 94.13%, 96.50%, 89.51%, and 93.46% respectively, while BCI and NDBI showed accuracy of 77.53%, 93.49%, 78.02%, and 84.03% and 58.25%, 57.53%, 77.77%, and 64.83%, respectively. In general, the proposed PISI is a convenient index to extract ISA with higher accuracy and better separability for ISA and soil as well as ISA and vegetation. Meanwhile, as PISI only uses blue and near-infrared bands, it can be used in a wider variety of remote sensing images.

scholarly journals Lithological mapping of East Tianshan area using integrated data fused by Chinese GF-1 PAN and ASTER multi-spectral data

2018 ◽  
Vol 10 (1) ◽  
pp. 532-543 ◽  
Author(s):  
Min Yang ◽  
Lei Kang ◽  
Huaqing Chen ◽  
Min Zhou ◽  
Jianghua Zhang
Keyword(s):  
Spectral Resolution ◽  
Near Infrared ◽  
Thermal Emission ◽  
Low Cost ◽  
Short Wave ◽  
Support Vector ◽  
Tianshan Mountain ◽  
Multispectral Data ◽  
Fusion Data ◽  
East Tianshan

Abstract The East Tianshan Mountain is one of the most important gold ore forming zones in northwestern China and central Asia. The Chinese GaoFen-1 (GF-1), the first Chinese high resolution satellite, is characterized by its 2-m resolution PAN data. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), the well-known earth observation satellite, is advanced by its finer spectral resolution owing 9 bands in the visible and near infrared (VNIR) to the short-wave infrared (SWIR) region. In this study, we fused the GF-1 PAN and the ASTER multispectral data using the well-known Gram-Schmidt Pan Sharpening (G-S) method to produce a new data with both high spatial and spectral resolution. Then different lithological units were mapped respectively using the fusion data, the ASTER data and the WorldView-3 data by support vector machine (SVM) method. In order to assess this fusion data, a comparison work was executed among the three mapping results. The comparison work indicated that lithological classification using the new fusion data is an efficient, robust and low cost method, and it could replace the WV-3 data in some large sale geological work.

scholarly journals Results from the Infrared Spectroscopy Experiment on Mariner 9

1974 ◽  
Vol 65 ◽  
pp. 293-294 ◽  
Author(s):  
J. Pearl ◽  
B. Conrath ◽  
R. Curran ◽  
R. Hanel ◽  
V. Kunde ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Spectral Range ◽  
Spectral Resolution ◽  
Thermal Emission ◽  
Emission Spectra ◽  
Spatial Coverage ◽  
Spectroscopy Experiment ◽  
Mariner 9

Over 20000 thermal emission spectra of Mars have been obtained, providing extensive diurnal, seasonal and spatial coverage of the planet. Each spectrum covers the spectral range from 200 to 2000 cm−1 with an apodized spectral resolution of 2.4 cm−1; the noise equivalent radiance of the instrument is 0.5 × 10−7 W cm−2 sr−1 (cm−1)−1.

scholarly journals Direct imaging of irregular satellite discs in scattered light

2020 ◽  
Vol 492 (4) ◽  
pp. 5709-5720
Author(s):  
Loic Nassif-Lachapelle ◽  
Daniel Tamayo
Keyword(s):  
Near Infrared ◽  
Thermal Emission ◽  
Scattered Light ◽  
Semimajor Axis ◽  
Detection Methods ◽  
Direct Imaging ◽  
Irregular Satellites ◽  
Long Period ◽  
Wide Range ◽  
Collisional Evolution

ABSTRACT Direct imaging surveys have found that long-period super-Jupiters are rare. By contrast, recent modelling of the widespread gaps in protoplanetary discs revealed by Atacama Large Millimetre Array suggests an abundant population of smaller Neptune to Jupiter-mass planets at large separations. The thermal emission from such lower-mass planets is negligible at optical and near-infrared wavelengths, leaving only their weak signals in reflected light. Planets do not scatter enough light at these large orbital distances, but there is a natural way to enhance their reflecting area. Each of the four giant planets in our Solar system hosts swarms of dozens of irregular satellites, gravitationally captured planetesimals that fill their host planets’ spheres of gravitational influence. What we see of them today are the leftovers of an intense collisional evolution. At early times, they would have generated bright circumplanetary debris discs. We investigate the properties and detectability of such irregular satellite discs (ISDs) following models for their collisional evolution from Kennedy & Wyatt (2011). We find that the scattered light signals from such ISDs would peak in the 10–100 au semimajor axis range implied by ALMA, and can render planets detectable over a wide range of parameters with upcoming high-contrast instrumentation. We argue that future instruments with wide fields of view could simultaneously characterize the atmospheres of known close-in planets, and reveal the population of long-period Neptune–Jupiter mass exoplanets inaccessible to other detection methods. This provides a complementary and compelling science case that would elucidate the early lives of planetary systems.

scholarly journals Photolysis of SiH4 by the Third Harmonic of a Nd:YAG Laser at 355 NM

1996 ◽  
Vol 16 (4) ◽  
pp. 245-253
Author(s):  
K. Sentrayan ◽  
E. Haque ◽  
A. Michael ◽  
V. S. Kushawaha
Keyword(s):  
Laser Energy ◽  
Emission Spectra ◽  
Photon Absorption ◽  
Absorption Process ◽  
Third Harmonic ◽  
Two Photon Absorption ◽  
Two Photon ◽  
The Third ◽  
Atomic Lines ◽  
White Deposit

The photolysis of silane (SiH4) was carried out using the third harmonic of a Nd: YAG laser at 355 nm, at a fixed SiH4 pressure of 350 Torr, varying the laser energy fluence in the range of 30–300 Jcm-2. The emission spectra indicates that the photofragments formed are SiH2, SiH, Si, H2, and H. The (A1B1-X1A1) transitions at 552.7 nm, 525.3 nm, 505.6 nm, and 484.7 nm of SiH2 are due to a two photon absorption process. The (A2Δ-X2π) transitions of SiH at 425.9 nm, 418 nm, 414.2 nm, 412.8 nm and 395.6 nm are due to a three photon absorption process. The brownish white deposit on the cell windows indicates the presence of amorphous silicon (a:Si-H). The two atomic lines of Si(4s1P0→ 3p21D2) at 288.1 nm, and (4s3Pj→ 3P3Pj) at 251.6 nm are observed. The atomic Si transitions are due to a three photon absorption. We observed seven transitions due to molecular hydrogen at wavelengths 577.5 nm, 565.5 nm, 534.4 nm, 542.5 nm, 471 nm, 461.7 nm, and 455.4 nm. These bands are due to a four photon absorption proc6ss. In addition to the molecular bands we also observed hydrogen atomic lines Hβ, Hγ and Hδ.

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