Non-Gaussian statistics of amide I mode frequency fluctuation of N-methylacetamide in methanol solution: Linear and nonlinear vibrational spectra

2004 ◽  
Vol 120 (3) ◽  
pp. 1477-1490 ◽  
Author(s):  
Kijeong Kwac ◽  
Hochan Lee ◽  
Minhaeng Cho
Author(s):  
V. M. Artyushenko ◽  
V. I. Volovach

The questions connected with mathematical modeling of transformation of non-Gaussian random processes, signals and noise in linear and nonlinear systems are considered and analyzed. The mathematical transformation of random processes in linear inertial systems consisting of both series and parallel connected links, as well as positive and negative feedback is analyzed. The mathematical transformation of random processes with polygamous density of probability distribution during their passage through such systems is considered. Nonlinear inertial and non-linear systems are analyzed.


2021 ◽  
Author(s):  
Jorge Luis Chau ◽  
Raffaele Marino ◽  
Fabio Feraco ◽  
Juan M. Urco ◽  
Gerd Baumgarten ◽  
...  

<p>The polar summer mesosphere is the Earth’s coldest region, allowing the formation of mesospheric ice clouds, potentially linked to climate change. These clouds produce strong radar echoes that are used as tracers of mesospheric dynamics. Here we report the first observations of extreme vertical drafts in the mesosphere, characterized by velocities larger than 40 m/s, i.e., more than five standard deviations larger than the observed wind variability. The morphology seems to resemble mesospheric bores, however the scales observed are much larger. Powerful vertical drafts, intermittent in space and time, emerge also in direct numerical simulations of stratified flows, predicting non-Gaussian statistics of vertical velocities. This evidence suggests that mesospheric bores might result from the interplay of gravity waves and turbulent motions. Our extreme event is interpreted as a mesospheric "super-bore", impacting mesospheric mixing and ice-formation, and would potentially impact planning of sub-orbital flights, and the investigation of biological material in the near space.</p>


2020 ◽  
Vol 29 (6) ◽  
pp. 064203 ◽  
Author(s):  
Hao Ni ◽  
Chunhao Liang ◽  
Fei Wang ◽  
Yahong Chen ◽  
Sergey A. Ponomarenko ◽  
...  

2007 ◽  
Vol 75 (3) ◽  
Author(s):  
Roberto Festa ◽  
Andrea Mazzino ◽  
Marco Tizzi

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