High resolution spectroscopy of the Ar-D2O and Ar-HDO molecular complexes in the near-infrared range

2013 ◽  
Vol 138 (10) ◽  
pp. 104307 ◽  
Author(s):  
K. Didriche ◽  
T. Földes
2014 ◽  
Vol 105 (4) ◽  
pp. 041903 ◽  
Author(s):  
Hiroaki Matsui ◽  
Wasanthamala Badalawa ◽  
Takayuki Hasebe ◽  
Shinya Furuta ◽  
Wataru Nomura ◽  
...  

2020 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Dianjun Hu ◽  
Xin Liu ◽  
Ziyu Liu ◽  
Xiaoying Li ◽  
Feng Tian ◽  
...  

As a kind of promising material for a Faraday isolator used in the visible and near infrared range, Dy2O3 transparent ceramics were prepared by vacuum sintering from the nano-powders synthesized by the liquid precipitation method using ammonium hydrogen carbonate as precipitant with no sintering aids. The synthesized precursor was calcinated at 950 °C–1150 °C for 4 h in air. The influences of the calcination temperature on the morphologies and phase composition of Dy2O3 powders were characterized. It is found that the Dy2O3 powder calcinated at 1000 °C for 4 h is superior for the fabrication of Dy2O3 ceramics. The Dy2O3 transparent ceramic sample prepared by vacuum sintering at 1850 °C for 10 h, and subsequently with air annealing at 1400 °C for 10 h, from the 1000 °C-calcined Dy2O3 powders, presents the best optical quality. The values of in-line transmittance of the optimal ceramic specimen with the thickness of 1.0 mm are 75.3% at 2000 nm and 67.9% at 633 nm. The Verdet constant of Dy2O3 ceramics was measured to be −325.3 ± 1.9 rad/(T·m) at 633 nm, about 2.4 times larger than that of TGG (Tb3Ga5O12) single crystals.


2017 ◽  
Author(s):  
K. Max Zhang ◽  
Bo Yang ◽  
Geng Chen ◽  
Jiajun Gu ◽  
James Schwab ◽  
...  

Abstract. DC, also referred to as Delta-C, measures enhanced light absorption of particulate matter (PM) samples at the near-ultraviolet (UV) range relative to the near-infrared range, which has been proposed previously as a woodsmoke marker due to the presence of enhanced UV light absorbing materials from wood combustion. In this paper, we further evaluated the applications and limitations of using DC as both a qualitative and semi-quantitative woodsmoke marker via joint continuous measurements of PM2.5 (by nephelometer pDR-1500) and light-absorptive PM (by 2-wavelength and 7-wavelength Aethalometer®) in three Northeastern U.S. cities/towns including Rutland, VT, Saranac Lake, NY and Ithaca, NY. We compared the pDR-1500 against a FEM PM2.5 sampler (BAM 1020), and identified a close agreement between the two instruments in a woodsmoke-dominated ambient environment. The analysis of seasonal and diurnal trends of DC, BC (880 nm) and PM2.5 concentrations supports the use of DC as an adequate qualitative marker. The strong linear relationships between PM2.5 and DC in both woodsmoke-dominated ambient and plume environments suggest that DC can reasonably serve as a semi-quantitative woodsmoke marker. We proposed a DC-based indicator for woodsmoke emission, which was then shown to exhibit relatively strong linear relationship with heating demand. While we observed reproducible PM2.5-DC relationships in similar woodsmoke-dominated ambient environments, those relationships differ significantly with different environments, and among individual woodsmoke sources. DC correlated much more closely with PM2.5 than EcoChem PAS2000-reported PAH in woodsmoke-dominated ambient environments. Our analysis also indicates the potential for PM2.5-DC relationships to be utilized to distinguish different combustion and operating conditions of woodsmoke sources, and that DC-Heating demand relationships could be adopted to estimate woodsmoke emissions. However, future studies are needed to elucidate those relationships.


Geosciences ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 289 ◽  
Author(s):  
Serena Benatti

Exoplanet research has shown an incessant growth since the first claim of a hot giant planet around a solar-like star in the mid-1990s. Today, the new facilities are working to spot the first habitable rocky planets around low-mass stars as a forerunner for the detection of the long-awaited Sun-Earth analog system. All the achievements in this field would not have been possible without the constant development of the technology and of new methods to detect more and more challenging planets. After the consolidation of a top-level instrumentation for high-resolution spectroscopy in the visible wavelength range, a huge effort is now dedicated to reaching the same precision and accuracy in the near-infrared. Actually, observations in this range present several advantages in the search for exoplanets around M dwarfs, known to be the most favorable targets to detect possible habitable planets. They are also characterized by intense stellar activity, which hampers planet detection, but its impact on the radial velocity modulation is mitigated in the infrared. Simultaneous observations in the visible and near-infrared ranges appear to be an even more powerful technique since they provide combined and complementary information, also useful for many other exoplanetary science cases.


2019 ◽  
Vol 85 (3) ◽  
pp. 20-26
Author(s):  
Viktoria Sabov ◽  
Мaria Potorij ◽  
Iwan Kityk ◽  
Mykhailo Filep ◽  
Marian Sabov

Complex chalcogenides display semiconductor properties. In particular, heavy metal compounds that are formed in the Tl2Se-Sb2Se3 system are good thermoelectric materials. At the same time TlSbP2Se6 compound belongs to the family of hexaseleno-hypodiphosphates, which representatives have a number of interesting properties (optoelectric, non-linear, etc.) in the near infrared range. The combination of these properties in one material causes some scientific and practical interest, therefore our research was aimed to study the nature of the interaction between TlSbP2Se6 and the thermally stable phases of the Tl2Se-Sb2Se3 system in order to find new promising candidate for applications in electronic devices. The alloys were prepared from corresponding binary, ternary compounds and quaternary TlSbP2Se6 by a direct one-temperature method in evacuated quartz ampoules at temperatures above the melting point of the initial and final products. The initial compounds were synthesized by the reaction of their high purity component elements in stoichiometric proportion. According to the results of the research, it was found that cross-sections based on TlSbP2Se6 and the thermally stable compounds of the Tl2Se-Sb2Se3 section are quasibinary: Sb2Se3–TlSbP2Se6 and TlSbSe2–TlSbP2Se6. Tl9SbSe6 – TlSbP2Se6 and Tl2Se - TlSbP2Se6 systems are not quasibinary, instead quasibinary sections Tl2Se-Tl4P2Se6 and Tl9SbSe6-Tl4P2Se6 which crossing their. The phase equilibrium in Sb2Se3 – TlSbP2Se6 and TlSbSe2 – TlSbP2Se6 systems were studied by common differential thermal analysis (DTA), X-ray powder diffraction (XRD) and microstructure analysis. The eutectic interactions are observed in both systems. The invariant points coordinates are: 77 mol.% TlSbP2Se6, 709 K (system Sb2Se3 – TlSbP2Se6) and 45 mol.% TISbSe2, 680 K (system TlSbSe2 – TlSbP2Se6). Significant boundary solid solutions are formed on the basis of the quaternary compound. Their region extends up to 10 mol% in the system Sb2Se3 – TlSbP2Se6 and to about 18 mol.% in the system TlSbSe2 –TlSbP2Se6 at annealing temperature (573 К). Near the Sb2Se3 and TlSbSe2, the solubility limits do not exceed several mol.%.


Author(s):  
Gloria Guilluy ◽  
Alessandro Sozzetti ◽  
Paolo Giacobbe ◽  
Aldo S. Bonomo ◽  
Giuseppina Micela

AbstractSince the first discovery of an extra-solar planet around a main-sequence star, in 1995, the number of detected exoplanets has increased enormously. Over the past two decades, observational instruments (both onboard and on ground-based facilities) have revealed an astonishing diversity in planetary physical features (i. e. mass and radius), and orbital parameters (e.g. period, semi-major axis, inclination). Exoplanetary atmospheres provide direct clues to understand the origin of these differences through their observable spectral imprints. In the near future, upcoming ground and space-based telescopes will shift the focus of exoplanetary science from an era of “species discovery” to one of “atmospheric characterization”. In this context, the Atmospheric Remote-sensing Infrared Exoplanet Large (Ariel) survey, will play a key role. As it is designed to observe and characterize a large and diverse sample of exoplanets, Ariel will provide constraints on a wide gamut of atmospheric properties allowing us to extract much more information than has been possible so far (e.g. insights into the planetary formation and evolution processes). The low resolution spectra obtained with Ariel will probe layers different from those observed by ground-based high resolution spectroscopy, therefore the synergy between these two techniques offers a unique opportunity to understanding the physics of planetary atmospheres. In this paper, we set the basis for building up a framework to effectively utilise, at near-infrared wavelengths, high-resolution datasets (analyzed via the cross-correlation technique) with spectral retrieval analyses based on Ariel low-resolution spectroscopy. We show preliminary results, using a benchmark object, namely HD 209458 b, addressing the possibility of providing improved constraints on the temperature structure and molecular/atomic abundances.


Author(s):  
Ali Zia ◽  
Jie Liang

Plant phenomics research requires different types of sensors employed to measure the physical traits of plant surface and to estimate the biomass. Of particular interests is the hyperspectral imaging device which captures wavelength indexed band images that characterize material properties of objects under study. This chapter introduces a proof of concept research that builds 3D plant model directly from hyperspectral images captured in a controlled lab environment. The method presented in this chapter allows fine structural-spectral information of an object be captured and integrated into the 3D model, which can be used to support further research and applications. The hyperspectral imaging has shown clear advantages in segmenting plant from its background and is very promising in generating comprehensive 3D plant models.


Sign in / Sign up

Export Citation Format

Share Document