Stable Singlet Biradicals of Rare‐Earth‐Fused Diporphyrin‐Triple‐Decker Complexes with Low Energy Gaps and Multi‐Redox States

2019 ◽  
Author(s):  
Sunri Lee ◽  
Ken‐ichi Yamashita ◽  
Naoya Sakata ◽  
Yasukazu Hirao ◽  
Kaya Ogawa ◽  
...  
Keyword(s):  
Rare Earth ◽  
Low Energy ◽  
Redox States ◽  
Energy Gaps

scholarly journals Direct Drive Applications: Possible Replacement of Rare-Earth Permanent Magnet Motors

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8058
Author(s):  
Chaelim Jeong ◽  
Luca Cinti ◽  
Nicola Bianchi
Keyword(s):  
Rare Earth ◽  
Permanent Magnet ◽  
Low Energy ◽  
Direct Drive ◽  
Permanent Magnet Motors ◽  
Stator Flux ◽  
Type Motor

This paper deals with the possibility to replace rare-earth permanent magnet (PM) motors in direct drive applications. According to previous researches, there are alternatives such as surface-mounted PM motors and spoke-type motors adopting Ferrite PMs, synchronous reluctance motors, with or without the assistance of low-energy PMs. Few studies have been carried out to compare all models at once, thus it is hard to choose which type motor is to be preferred as a valid alternative of rare-earth PM motors in direct drive applications. In this paper, the representative candidates listed above are analyzed and the results are compared with that of a rare-earth PM motor, which is considered as a reference motor. Additionally, the demagnetization phenomenon of the motors with Ferrite PMs is deeply analyzed because this kind of PM may be easily demagnetized by the stator flux. Finally, both strengths and weaknesses of each alternative motors are highlighted.

EXCEPTIONAL STRUCTURES IN THE ODD-ODD NUCLEUS 250Md

2000 ◽  
Vol 09 (04) ◽  
pp. 309-317 ◽  
Author(s):  
P. C. SOOD ◽  
M. SAINATH ◽  
K. VENKATARAMANIAH
Keyword(s):  
Rare Earth ◽  
Energy Spectrum ◽  
Ground State ◽  
Low Energy ◽  
Α Decay ◽  
Decay Modes ◽  
Proton Interaction ◽  
Zero Range ◽  
Singlet Band ◽  
Rare Earth Nucleus

The low-energy two-quasiparticle bandhead energies for the odd-odd Z=101 nucleus 250 Md are evaluated using a zero range residual neutron-proton interaction. The 250Md ground state is seen to have the spin-parity Iπ=0- corresponding to the singlet band from the configuration {p : 7/2[514]⊗n:7/2[624]} in violation of the Gallagher-Moszkowski (GM) coupling rule. The situation here is shown to be almost identical to that for the rare-earth nucleus 166 Ho , which is the only well-established exception to the GM rule known so far. Analysis of the expected low energy spectrum, including the rotational levels, for 250 Md reveals the occurrence of an as-yet-unobserved long-lived high-spin Iπ = 7- isomeric state around (80±30) keV with dominant ε and α decay modes.

scholarly journals Spectroscopic evidence of low-energy gaps persisting up to 120 K in surface-doped p -terphenyl crystals

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Haoxiang Li ◽  
Xiaoqing Zhou ◽  
Stephen Parham ◽  
Thomas Nummy ◽  
Justin Griffith ◽  
...  
Keyword(s):  
Low Energy ◽  
Spectroscopic Evidence ◽  
Energy Gaps

scholarly journals Mechanisms Affecting Emission in Rare-Earth-Activated Phosphors

2000 ◽  
Vol 621 ◽  
Author(s):  
David R. Tallant ◽  
Carleton H. Seager ◽  
Regina L. Simpson
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Lower Energy ◽  
Electron Beams ◽  
Low Energy ◽  
Flat Panel Displays ◽  
Relaxation Model ◽  
Activator Concentration ◽  
Flat Panel ◽  
Low Energy Electron

ABSTRACTThe relatively poor efficiency of phosphor materials in cathodoluminescence with low accelerating voltages is a major concern in the design of field emission flat panel displays operated below 5 kV. Our research on rare-earth-activated phosphors indicates that mechanisms involving interactions of excited activators have a significant impact on phosphor efficiency. Persistence measurements in photoluminescence (PL) and cathodoluminescence (CL) show significant deviations from the sequential relaxation model. This model assumes that higher excited manifolds in an activator de-excite primarily by phonon-mediated sequential relaxation to lower energy manifolds in the same activator ion. In addition to sequential relaxation, there appears to be strong coupling between activators, which results in energy transfer interactions. Some of these interactions negatively impact phosphor efficiency by nonradiatively de-exciting activators. Increasing activator concentration enhances these interactions. The net effect is a significant degradation in phosphor efficiency at useful activator concentrations, which is exaggerated when low–energy electron beams are used to excite the emission.

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