A cross-national comparison of medicinal plants used by the Miao, Yi and Lisu ethnic groups in Yanbian, China

Background The Miao, Yi and Lisu ethnic groups all have traditional medicinal knowledge, and the unique climate and topography of Yanbian County make it rich in medicinal plants. So the exchange, collision and integration of medical cultures of ethnic minorities in Yanbian County have research significance. The study compared and analyzed the similarities and differences in the traditional medicinal usage of the Miao, Yi and Lisu ethnic groups in Yanbian, to provide the basis for the traditional medicinal culture and characteristics of the three medical systems in southwest China. Methods 36 sample plots were selected in this study and 5 sample quadrats were randomly set up in each plot to collect specimens. Identified the collected medicinal plant specimens, and sort out the catalog of medicinal plants of Miao medicine (MM), Yi medicine (YM) and Lisu medicine (LM) in Yanbian County. The catalog includes scientific name, family names, latin names, medicinal parts, and diseases treated, etc. The existing traditional doctors were interviewed to supplement the efficacy and usage of the medicinal plants in the catalog. Finally, the similarities and differences of the three medical systems were analyzed and sorted out the special medication in each ethnic group. Results Among the medicinal plants collected in the sample plot survey, 345 species of 299 genera and 109 families are used in the 3 medical systems. 102 species are shared-use in MM, YM and LM, among which Compositae (14 species, 14%), Labiatae (6 species, 6%), Polygonaceae (4 species, 4%) and Rosaceae (4 species, 4%) were the dominant families. The statistical data shows that the Jaccard similarity index (JI) of the MM and YM is the highest (47.6%), and the whole similarity percentage of the drug system is the highest (45.9%). A total of 18 special usages were used in MM, YM and LM in Yanbian. Conclusions The results show that a large number of shared-use medicinal plants in MM, YM and LM in Yanbian County. The reason may be the intersecting medicine collecting location, frequent market communications and exchanges, and the influence of Han medicine. The more similar geographic environment, vegetation types, lifestyles, and closer spatial distance have resulted in MM and YM in Yanbian County being more parallel than those of LM.

Darboux Transformation and N-Soliton Solution for the Coupled Modified Nonlinear Schrödinger Equations

The pulse propagation in the picosecond or femtosecond regime of birefringent optical fibers is governed by the coupled mixed derivative nonlinear Schr¨odinger (CMDNLS) equations. A new type of Lax pair associated with such coupled equations is derived from the Wadati-Konno-Ichikawa spectral problem. The Darboux transformation method is applied to this integrable model, and the N-times iteration formula of the Darboux transformation is presented in terms of the compact determinant representation. Starting from the zero potential, the bright vector N-soliton solution of CMDNLS equations is expressed as a compact determinant by N complex eigenvalues and N linearly independent eigenfunctions. The collision mechanisms in two components shows that bright vector solitons can exhibit the standard elastic and inelastic collisions. Such energy-exchange collision behaviours have potential applications in the construction of logical gates, the design of fiber directional couplers, and quantum information processors.

Applications Aspects of the Diffusion of Slow Electrons in the Ionospheric Gases

The paper presents the results of precise of the calculations of the diffusion of slow electrons in ionospheric gases, such as, (Argon – Hydrogen mixture, pure Nitrogen and Argon – Helium – Nitrogen) in the presence of a uniform electric field and temperature 300 Kelvin. Such calculations lead to the value Townsend's energy coefficient (KT) as a function of E/P (electric field strength/gas pressure), electric field (E), electric drift velocity (Vd), momentum transfer collision frequency ( ), energy exchange collision frequency ( ) and characteristic energy (D/?). The following physical quantities are deduced as function s E/P: mean free path of the electrons at unit pressure, mean energy lost by an electron per collision, mean velocity of agitation and the collisional cross-section of the molecules. The results are presented graphically and in tabular form. This results appeared a good agreement with the experimental data.