scholarly journals Ultra‐narrow band blue emission of Eu 2+ in halogenated (Alumino)borate systems based on high lattice symmetry

2018 ◽  
Author(s):  
Yi Wei ◽  
Xingyu Qu ◽  
Guogang Li ◽  
Ziyong Cheng ◽  
Maxim S. Molokeev ◽  
...  
Keyword(s):  
Narrow Band ◽  
Blue Emission ◽  
Lattice Symmetry ◽  
Borate Systems

A narrow-band blue emitting phosphor Ca8Mg7Si9N22:Eu2+ for pc-LEDs

2019 ◽  
Vol 7 (13) ◽  
pp. 3730-3734 ◽  
Author(s):  
Chao Li ◽  
Xiao-Ming Wang ◽  
Feng-Feng Chi ◽  
Zu-Pei Yang ◽  
Huan Jiao
Keyword(s):  
Emission Intensity ◽  
Room Temperature ◽  
Narrow Band ◽  
Blue Emission ◽  
Thermal Quenching ◽  
Unit Cell ◽  
Photoluminescence Emission ◽  
Space Group

Ca8Mg7Si9N22 crystallizes in a tetragonal space group P42/nmc (No. 137) with a unit cell of a = 7.3271(11) Å and c = 10.336(2) Å. Ca8Mg7Si9N22:Eu2+ shows a narrow-band blue emission peaking at 400 nm with an intriguing bandwidth ∼34 nm and shows remarkably high thermal quenching resistance, maintaining 92% photoluminescence emission intensity at 420 K and 75% at 700 K of that measured at room temperature.

ZnO nanocrystals with narrow-band blue emission

2019 ◽  
Vol 205 ◽  
pp. 508-518 ◽  
Author(s):  
M. Sasani Ghamsari ◽  
S. Alamdari ◽  
D. Razzaghi ◽  
M. Arshadi Pirlar
Keyword(s):  
Narrow Band ◽  
Blue Emission ◽  
Zno Nanocrystals

Multisite-Occupancy-Driven Intense Narrow-Band Blue Emission from Sr5SiO4Cl6:Eu2+ Phosphor with Excellent Stability and Color Performance

2020 ◽  
Vol 59 (3) ◽  
pp. 1928-1939 ◽  
Author(s):  
Somrita Dutta ◽  
Sudipta Som ◽  
Mohan Lal Meena ◽  
Rajneesh Chaurasiya ◽  
Teng-Ming Chen
Keyword(s):  
Narrow Band ◽  
Blue Emission ◽  
Excellent Stability

Discovery of a novel rare-earth free narrow-band blue-emitting phosphor Y3Al2Ga3O12:Bi3+ with strong NUV excitation for LCD LED backlights

2020 ◽  
Vol 8 (39) ◽  
pp. 13668-13675 ◽  
Author(s):  
Chibin Zheng ◽  
Puxian Xiong ◽  
Mingying Peng ◽  
Huailu Liu
Keyword(s):  
Rare Earth ◽  
Narrow Band ◽  
Blue Emission ◽  
Selective Excitation ◽  
Rare Earth Doped

Herein, an emerging no-rare earth doped and narrow-band blue-emitting phosphor of Y3Al2Ga3O12: Bi3+ with narrow-band blue emission peaking at 410 nm with FWHM of 39 nm, is pioneeringly developed via selective excitation.

A zero-thermal-quenching perovskite-like phosphor with an ultra-narrow-band blue-emission for wide color gamut backlight display applications

2021 ◽  
Vol 9 (39) ◽  
pp. 13722-13732 ◽  
Author(s):  
Zhihua Leng ◽  
Dan Zhang ◽  
Hao Bai ◽  
Hongbo He ◽  
Qing Qing ◽  
...  
Keyword(s):  
Narrow Band ◽  
Blue Emission ◽  
Thermal Quenching ◽  
Color Gamut ◽  
Wide Color Gamut

A novel perovskite-like K2BaPO4F:Eu2+ phosphor exhibits an unprecedented ultra-narrow-band (FWHM = 25 nm) blue-emission (λem = 439 nm) and a zero-thermal-quenching property up to a temperature of 125 °C.

Statistical analysis of classification

1966 ◽  
Vol 24 ◽  
pp. 188-189
Author(s):  
T. J. Deeming
Keyword(s):  
Multivariate Analysis ◽  
Statistical Analysis ◽  
Classification Scheme ◽  
Analytical Procedure ◽  
Narrow Band ◽  
Scientific Research ◽  
Maximum Amount ◽  
Amount Of Information

If we make a set of measurements, such as narrow-band or multicolour photo-electric measurements, which are designed to improve a scheme of classification, and in particular if they are designed to extend the number of dimensions of classification, i.e. the number of classification parameters, then some important problems of analytical procedure arise. First, it is important not to reproduce the errors of the classification scheme which we are trying to improve. Second, when trying to extend the number of dimensions of classification we have little or nothing with which to test the validity of the new parameters.Problems similar to these have occurred in other areas of scientific research (notably psychology and education) and the branch of Statistics called Multivariate Analysis has been developed to deal with them. The techniques of this subject are largely unknown to astronomers, but, if carefully applied, they should at the very least ensure that the astronomer gets the maximum amount of information out of his data and does not waste his time looking for information which is not there. More optimistically, these techniques are potentially capable of indicating the number of classification parameters necessary and giving specific formulas for computing them, as well as pinpointing those particular measurements which are most crucial for determining the classification parameters.

Photo-electric Hβ and uvby photometry

1966 ◽  
Vol 24 ◽  
pp. 170-180
Author(s):  
D. L. Crawford
Keyword(s):  
Narrow Band ◽  
Line Strength ◽  
Interference Filter ◽  
B Stars ◽  
Relative Line ◽  
The Mean ◽  
F Stars ◽  
Two Parameters ◽  
Filter Photometry ◽  
The Continuum

Early in the 1950's Strömgren (1, 2, 3, 4, 5) introduced medium to narrow-band interference filter photometry at the McDonald Observatory. He used six interference filters to obtain two parameters of astrophysical interest. These parameters he calledlandc, for line and continuum hydrogen absorption. The first measured empirically the absorption line strength of Hβby means of a filter of half width 35Å centered on Hβand compared to the mean of two filters situated in the continuum near Hβ. The second index measured empirically the Balmer discontinuity by means of a filter situated below the Balmer discontinuity and two above it. He showed that these two indices could accurately predict the spectral type and luminosity of both B stars and A and F stars. He later derived (6) an indexmfrom the same filters. This index was a measure of the relative line blanketing near 4100Å compared to two filters above 4500Å. These three indices confirmed earlier work by many people, including Lindblad and Becker. References to this earlier work and to the systems discussed today can be found in Strömgren's article inBasic Astronomical Data(7).

Southern Hemisphere Seti Survey: Five Years of Project Meta II

1997 ◽  
Vol 161 ◽  
pp. 611-621
Author(s):  
Guillermo A. Lemarchand ◽  
Fernando R. Colomb ◽  
E. Eduardo Hurrell ◽  
Juan Carlos Olalde
Keyword(s):  
Southern Hemisphere ◽  
Scattering Theory ◽  
Galactic Plane ◽  
Narrow Band ◽  
Neutral Hydrogen ◽  
Sky Survey ◽  
Inertial Frames ◽  
Interstellar Scattering ◽  
Extraterrestrial Origin ◽  
Spectral Channels

AbstractProject META II, a full sky survey for artificial narrow-band signals, has been conducted from one of the two 30-m radiotelescopes of the Instituto Argentino de Radioastronomía (IAR). The search was performed near the 1420 Mhz line of neutral hydrogen, using a 8.4 million channels Fourier spectrometer of 0.05 Hz resolution and 400 kHz instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earths rotation, which provides a characteristic changing signature for narrow-band signals of extraterrestrial origin. Among the 2 × 1013spectral channels analyzed, 29 extra-statistical narrow-band events were found, exceeding the average threshold of 1.7 × 10−23Wm−2. The strongest signals that survive culling for terrestrial interference lie in or near the galactic plane. A description of the project META II observing scheme and results is made as well as the possible interpretation of the results using the Cordes-Lazio-Sagan model based in interstellar scattering theory.

Sign in / Sign up

Export Citation Format

Share Document