35 research outputs found

    Multiple-type solutions for multipole interface solitons in thermal nonlinear media

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    We address the existence of multipole interface solitons in one-dimensional thermal nonlinear media with a step in the linear refractive index at the sample center. It is found that there exist two types of solutions for tripole and quadrupole interface solitons. The two types of interface solitons have different profiles, beam widths, mass centers, and stability regions. For a given propagation constant, only one type of interface soliton is proved to be stable, while the other type can also survive over a long distance. In addition, three types of solutions for fifth-order interface solitons are found.Comment: 5 pages, 5 figure

    Solitons in thermal media with periodic modulation of linear refractive index

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    We address the existence and properties of solitons in thermal media with periodic modulation of linear refractive index. Many kinds of solitons in such optical lattices, including symmetric and antisymmetric lattices, are found under different conditions. We study the influence of the refractive index difference between two different layers on solitons. It is also found that there do not exist cutoff value of propagation constant and soliton power for shifted lattice solitons. In addition, the solitons launched away from their stationary position may propagate without oscillation when the confinement from lattices is strong.Comment: 6 pages, 6 figure

    Defect solitons supported by nonlocal PT symmetric superlattices

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    The existence and stability of defect solitons supported by parity-time (PT) symmetric superlattices with nonlocal nonlinearity are investigated. In the semi-infinite gap, in-phase solitons are found to exist stably for positive or zero defects, but can not exist in the presence of negative defects with strong nonlocality. In the first gap, out-of-phase solitons are stable for positive or zero defects, whereas in-phase solitons are stable for negative defects. The dependence of soliton stabilities on modulation depth of the PT potentials is studied. It is interesting that solitons can exist stably for positive and zero defects when the PT potentials are above the phase transition points.Comment: 12 figures, 6 pages, Accepted by EP

    Comparative studies on the regulatory effects of raw and charred hawthorn on functional dyspepsia and intestinal flora

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    Purpose: To compare the effects of raw hawthorn (RH) and charred hawthorn (CH) on functional dyspepsia (FD) and intestinal flora (IF).Methods: A rat model of FD was established through use of a chronic stimulator. Rat models were evaluated by the rat’s physical state, body weight, diet, and histopathological examination. After RH or CH administration, the digestive function of the rats was evaluated by determining gastric emptying and intestinal propulsion rate, diversity of intestinal flora.Results: RH and CH both improved gastric emptying and intestinal propulsion rate in FD group when compared to control group (p < 0.05). CH yielded higher treatment effectiveness than RH. Sixteen phyla of microbiomes were recognized from all samples. After FD model establishment, the relative abundance of Lactobacillus, Lachnospiraceae and Bacteroidales decreased compared to normal control rats. On the other hand, the relative abundance of Helicobacter and Bacteroides in the model control group increased compared to normal control. After RH and CH treatment, the relative abundance of all dysregulated phyla was restored to varying degrees, but the levels after CH treatment were similar to those of the normal control group.Conclusion: The relative abundance of intestinal flora of FD model rats is significantly different from that of rats in normal control group. Thus, RH and CH intervention improves digestive function, and the mechanisms may be related to adjustment of gut dysbacteriosis.Keywords: Raw Hawthorn, Charred Hawthorn, Functional dyspepsia, Intestinal flor
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