The effects of time delay on the decline and propagation processes of population in the Malthus-Verhulst model with cross-correlated noises

The effects of time delay on the decline and propagation processes of population in the Malthus-Verhulst model with cross-correlated noises are investigated separately. Through numerically computing and stochastically simulating, we find that: (i) inclusion of time delay in the decline process, increasing the delay time τ weakens the stability of population with short delay and strengthens it with long delay. The stability of population reduces monotonically as the cross-correlated intensity λ increasing. The population of a species goes to extinction with increasing τ and increasing λ; (ii) inclusion of time delay in the propagation process, the increasing τ strengthens the stability of population and the increasing λ weakens it. The increasing τ slows down the growth process of a species while the increasing λ speeds it up. That is, the increasing delay time does not affect roughly the stability of population with short delay but strengthens it with long delay, and the population of species is restricted in the lower level by the larger delay time. The stability of population is weakened and the replacement of old individuals with young ones is accelerated by the increasing cross-correlation intensity between two noises

Structural Peculiarities of Ion-Conductive Organic-Inorganic Polymer Composites Based on Aliphatic Epoxy Resin and Salt of Lithium Perchlorate

Abstract The article is concerned with hybrid amorphous polymers synthesized basing on epoxy oligomer of diglycide aliphatic ester of polyethylene glycol that was cured by polyethylene polyamine and lithium perchlorate salt. Structural peculiarities of organic-inorganic polymer composites were studied by differential scanning calorimetry, wide-angle X-ray spectra, infrared spectroscopic, scanning electron microscopy, elemental analysis, and transmission and reflective optical microscopy. On the one hand, the results showed that the introduction of LiClO4 salt into epoxy polymer leads to formation of the coordinative metal-polymer complexes of donor-acceptor type between central Li+ ion and ligand. On the other hand, the appearance of amorphous microinclusions, probably of inorganic nature, was also found

Solvate Structures and Computational/Spectroscopic Characterization of Lithium Difluoro(oxalato)borate (LiDFOB) Electrolytes

Lithium difluoro(oxalato)borate (LiDFOB) is a relatively new salt designed for battery electrolyte usage. Limited information is currently available, however, regarding the ionic interactions of this salt (i.e., solvate formation) when it is dissolved in aprotic solvents. Vibrational spectroscopy is a particularly useful tool for identifying these interactions, but only if the vibrational bands can be correctly linked to specific forms of anion coordination. Single crystal structures of LiDFOB solvates have therefore been used to both explore the DFOB-center dot center dot center dot Li+ cation coordination interactions and serve as unambiguous models for the assignment of the Raman vibrational bands. The solvate crystal structures determined indude (monoglyme)(2):LiDFOB, (1,2-diethoxyethane)(3/2):LiDFOB, (acetonitrile)(3):LiDFOB, (acetonitrile)(1):LiDFOB, (dimethyl carbonate)(3/2):LiDFOB, (succinonitrile)(1):LiDFOB, (adiponitrile)(1):LiDFOB, (PMDETA)(1):LiDFOB, (CRYPT-222)(2/3):LiDFOB, and (propylene carbonate)(1):LiDFOB. DFT calculations have been incorporated to provide additional insight into the origin (i.e., vibrational modes) of the Raman vibrational bands to aid in the interpretation of the experimental analysis