scholarly journals Insulator-metal transition in dense fluid deuterium

Science ◽  
2018 ◽  
Vol 361 (6403) ◽  
pp. 677-682 ◽  
Author(s):  
Peter M. Celliers ◽  
Marius Millot ◽  
Stephanie Brygoo ◽  
R. Stewart McWilliams ◽  
Dayne E. Fratanduono ◽  
...  
Keyword(s):  
Refractive Index ◽  
Visible Light ◽  
Extrasolar Planets ◽  
Theoretical Calculations ◽  
Optical Measurements ◽  
Metallic Hydrogen ◽  
Insulator Metal Transition ◽  
Dense Fluid ◽  
Dynamic Experiments ◽  
Compressed Fluid

Dense fluid metallic hydrogen occupies the interiors of Jupiter, Saturn, and many extrasolar planets, where pressures reach millions of atmospheres. Planetary structure models must describe accurately the transition from the outer molecular envelopes to the interior metallic regions. We report optical measurements of dynamically compressed fluid deuterium to 600 gigapascals (GPa) that reveal an increasing refractive index, the onset of absorption of visible light near 150 GPa, and a transition to metal-like reflectivity (exceeding 30%) near 200 GPa, all at temperatures below 2000 kelvin. Our measurements and analysis address existing discrepancies between static and dynamic experiments for the insulator-metal transition in dense fluid hydrogen isotopes. They also provide new benchmarks for the theoretical calculations used to construct planetary models.

TEM characterization of proton-exchanged LiNbO3 optical waveguides

1986 ◽  
Vol 44 ◽  
pp. 480-481
Author(s):  
W. E. Lee
Keyword(s):  
Refractive Index ◽  
Benzoic Acid ◽  
Optical Waveguides ◽  
Total Internal Reflection ◽  
Index Of Refraction ◽  
Optical Measurements ◽  
Lithium Ions ◽  
Wide Channel ◽  
Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

Low-Cost Heat Insulating Film Design for BIPV Modules Based on Multi-Layer Inorganic Materials

2012 ◽  
Vol 452-453 ◽  
pp. 1424-1428
Author(s):  
Han Min Tian ◽  
Li Jia Guo ◽  
Wen Feng Duan ◽  
Rui Xia Yang ◽  
Feng Lan Tian
Keyword(s):  
Refractive Index ◽  
Visible Light ◽  
Absorption Rate ◽  
Heat Insulation ◽  
Low Cost ◽  
Heat Rate ◽  
Optimum Combination ◽  
Inorganic Materials ◽  
Tempered Glass ◽  
Glass Panel

By analyzing the transmitionce and heat rate of insulating antireflection films conposed by refractive-index adjustable SiO2 layer and TiO2 layers, the optimum combination of antireflection films of BIPV is obtained. The absorption rate at the ultraviolet part that wavelenght excessive inadequate 400nm of the optimized fils is 99.9%, which are directly designed on the surface of the low iron tempered glass panel of BIPV, and in the wavelength range 400nm-800nm, the visible light transmitionce rate is up to 99.5%, and the heat that wavelenght excessive 800nm is reflected of 20%. For the multilayer heat insulation films are composed with the same kind of material while with different refractive indexes, there is no projecting stress between these films and no constraints during the production process of different films for the possible low cost heat insulating of BIPV.

scholarly journals Methotrexate Detection Based On The Optical Properties Of Carbon Nanotubes And Silver Nano Particles Nanocomposites

2021 ◽  
Vol 7 (3) ◽  
pp. 1323
Author(s):  
Fida Mohammad Mohammadi
Keyword(s):  
Carbon Nanotubes ◽  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nano Particles ◽  
Optical Measurements ◽  
Carbon Electrode ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

<p>In this experiment, glassy carbon electrode with multi walled carbon nanotubes<br />nanocomposites have been prepared in different concentration in order to see if<br />methotrexate is anticancer drug. For the purpose of characterizing the structures,<br />nanocomposites were analyzed by scanning electron microscope. Optical measurements of different concentrations were conducted by z-scan method and the results show that by rising the concentration, nonlinear refractive index and linear absorption coefficient increases. The values of nonlinear refractive index are in orders of 𝟏𝟎−𝟖 𝒄𝒎𝟐 𝒘.</p>

scholarly journals Optical properties of AlN layers obtained by magnetron sputtering

2018 ◽  
Vol 36 (4) ◽  
pp. 717-721
Author(s):  
Piotr Potera ◽  
Grzegorz Wisz ◽  
Łukasz Szyller
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Energy Gap ◽  
Optical Measurements ◽  
Transmission Spectra ◽  
Glass Substrates ◽  
Different Content

AbstractThe growth of AlN layers on glass substrates using magnetron sputtering method was performed and the grown layers were subjected to optical measurements. Transmission spectra of the layers grown at different content of N2 in the atmosphere were obtained. The transmission spectra as well as energy gap depended on N2 content. The annealing of the layers in air led to transmission changes and influenced energy gap and refractive index values.

scholarly journals Large-Scale Uniform Silver Nanocave Array for Visible Light Refractive Index Sensing Using Soft UV Nanoimprint

2016 ◽  
Vol 8 (4) ◽  
pp. 1-7 ◽  
Author(s):  
Jinfeng Zhu ◽  
Yanqiang Bai ◽  
Lirong Zhang ◽  
Zhengyong Song ◽  
Hai Liu ◽  
...  
Keyword(s):  
Refractive Index ◽  
Visible Light ◽  
Large Scale ◽  
Refractive Index Sensing

A photoinduced reaction of perfluoroalkyl halides with 1,3-diarylprop-2-yn-1-ones catalyzed by DABSO

2017 ◽  
Vol 4 (9) ◽  
pp. 1745-1750 ◽  
Author(s):  
Yuewen Li ◽  
Yiye Lu ◽  
Runyu Mao ◽  
Zhiming Li ◽  
Jie Wu
Keyword(s):  
Sulfur Dioxide ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Halogen Bond ◽  
Theoretical Calculations ◽  
Light Irradiation ◽  
Efficient Catalyst ◽  
Photoinduced Reaction ◽  
Plausible Mechanism ◽  
Perfluoroalkyl Halides

The sulfur dioxide surrogate of DABCO·(SO2)2 is used as an efficient catalyst for the cleavage of the perfluoroalkyl-halogen bond under visible-light irradiation. A plausible mechanism supported by theoretical calculations is proposed.

Preparation of Diarylethene Substituted Polymer Films for Optical Recording

2001 ◽  
Vol 665 ◽  
Author(s):  
Song Yun Cho ◽  
Eunkyoung Kim
Keyword(s):  
Refractive Index ◽  
Visible Light ◽  
Polymer Films ◽  
Color Change ◽  
Refractive Index Change ◽  
Optical Recording ◽  
Acryloyl Chloride ◽  
Transparent Film ◽  
Index Change ◽  
Recorded Image

ABSTRACTEffect of photo-irradiation on the color change of diarylethene polymer films was investigated. Diarylethene polymer films were prepared from photopolymerization of a radical curable mixture of diarylethene compound and a fluoroalkylacrylate containing a photo initiator. 1-[6'-(Methacryloxyethyloxycarbonyl)-2'-methylbenzo[b]thiophene-3'-yl]-2- (2"-methylbenzo[b]thiophene-3"-yl)hexafluorocyclopentene (MMBTF6) was synthesized from 2,3-bis(2-methylbenzo[b]thiophene-3-yl)hexafluorocyclopentene (BTF6) in three steps. 2,2,3,3-Tetrafluoro-1,4-butyldiacrylate (TFBDA) was synthesized from the corresponding diol and acryloyl chloride in the presence of a base. The photocurable mixture was coated on a substrate and subjected to antinic irradiation, to afforded homogeneous transparent film. A mask image was recovered on the film by a light of 365 nm and read by a visible light (λ > 700 nm) without destruction of the image. To erase the recorded image, a white light or a visible light was irradiated. Photochromic quantum yield and photo-induced refractive index change of the diarylethene bound polymer film were determined as 0.12 and 0.0006 respectively.

scholarly journals Incorporation of reduced graphene oxide into faceted flower-like {001} TiO 2 for enhanced photocatalytic activity

2018 ◽  
Vol 5 (8) ◽  
pp. 180613 ◽  
Author(s):  
Haijin Liu ◽  
Peiyao Li ◽  
Haokun Bai ◽  
Cuiwei Du ◽  
Dandan Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Theoretical Calculations ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Photocatalytic Activities

Anatase TiO 2 with {001} facets is much more active than that with {101} facets, which has been verified via experiments and theoretical calculations. Graphene has garnered much attention since it was initially synthesized, due to its unique properties. In this study, reduced graphene oxide (RGO)/{001} faceted TiO 2 composites were fabricated via a solvothermal method. The composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectrophotometry, photoluminescence and Raman analysis. The results revealed that the graphene oxide was reduced during the preparation process of the {001} faceted TiO 2 , and combined with the surface of {001} TiO 2 . The photocatalytic activities of the composites were evaluated through the degradation of basic violet, under both white light ( λ > 390 nm) and visible light ( λ = 420 nm) irradiation. The results indicated that the photocatalytic activities of the {001} faceted TiO 2 were significantly improved following the incorporation of RGO, particularly under visible light irradiation. Theoretical calculations showed that the band structure of the {001} faceted TiO 2 was modified via graphene hybridization, where the separation of photoinduced electron–hole pairs was promoted; thus, the photocatalytic activity was enhanced.

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