Pure single line oscillation of HF lasers in fine atmospheric window

2021 ◽  
Vol 127 (6) ◽  
Author(s):  
Yuanhu Wang ◽  
Liucheng Li ◽  
Liping Duo ◽  
Yuqi Jin ◽  
Guofu Li ◽  
...  
Author(s):  
Alan Boyde ◽  
Milan Hadravský ◽  
Mojmír Petran ◽  
Timothy F. Watson ◽  
Sheila J. Jones ◽  
...  

The principles of tandem scanning reflected light microscopy and the design of recent instruments are fully described elsewhere and here only briefly. The illuminating light is intercepted by a rotating aperture disc which lies in the intermediate focal plane of a standard LM objective. This device provides an array of separate scanning beams which light up corresponding patches in the plane of focus more intensely than out of focus layers. Reflected light from these patches is imaged on to a matching array of apertures on the opposite side of the same aperture disc and which are scanning in the focal plane of the eyepiece. An arrangement of mirrors converts the central symmetry of the disc into congruency, so that the array of apertures which chop the illuminating beam is identical with the array on the observation side. Thus both illumination and “detection” are scanned in tandem, giving rise to the name Tandem Scanning Microscope (TSM). The apertures are arranged on Archimedean spirals: each opposed pair scans a single line in the image.


Author(s):  
Laurent Manceron ◽  
P. Roy ◽  
Cyril Richard ◽  
Michel Loete ◽  
Vincent Boudon ◽  
...  
Keyword(s):  

2020 ◽  
Vol 10 (4) ◽  
pp. 501-506
Author(s):  
Monisha Ghosh ◽  
Arindam Biswas ◽  
Aritra Acharyya

Aims:: The potentiality of Multiple Quantum Well (MQW) Impacts Avalanche Transit Time (IMPATT) diodes based on Si~3C-SiC heterostructures as possible terahertz radiators have been explored in this paper. Objective:: The static, high frequency and noise performance of MQW devices operating at 94, 140, and 220 GHz atmospheric window frequencies, as well as 0.30 and 0.50 THz frequency bands, have been studied in this paper. Methods: The simulation methods based on a Self-Consistent Quantum Drift-Diffusion (SCQDD) model developed by the authors have been used for the above-mentioned studies. Results: Thus the noise performance of MQW DDRs will be obviously better as compared to the flat Si DDRs operating at different mm-wave and THz frequencies. Conclusion:: Simulation results show that Si~3C-SiC MQW IMPATT sources are capable of providing considerably higher RF power output with the significantly lower noise level at both millimeter-wave (mm-wave) and terahertz (THz) frequency bands as compared to conventional flat Si IMPATT sources.


Author(s):  
G. O. Hutchinson

A further passage shows the imagination and craft of Achilles Tatius taken to a still greater degree, as he depicts the hero Cleitophon at the terrible crisis of believing his beloved to be dead. The narrative is suspended as the writer develops, at remarkable length, a psychological and physiological observation on delayed effects. Where Heliodorus had heaped up imagery with abundance, Achilles develops with skilled organization a single line of thought and imagery, developing it and enriching it as he goes. Rhythm plays a vital part in this remarkable union of tight order and inventive imagination. The expansion and the deployment of science have a Plutarchan element; but the fantasy and the tautness create something quite different out of rhythm.


Author(s):  
Ehsan Kayal ◽  
David R Smith

Abstract Mitochondrial DNA (mtDNA) is a universal hallmark of aerobic eukaryotes. That is why the recent suggestion by John et al. (2019) that the aerobic dinoflagellate Amoebophrya sp. strain AT5 (Syndiniales) lacks mtDNA was so remarkable. Here, by reanalysing recently published genomic and transcriptomic data from three Amoebophrya strains, we provide evidence of a cryptic, highly reduced mtDNA in this clade. More work is needed before one can definitively say if Amoebophrya has or does not have a mtDNA, but for now the data are pointing towards the existence of one. Ultimately, we urge caution when basing supposedly absent genomic features on single line evidences.


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