Numerical solutions for two nonlinear wave equations

The split-step pseudo-spectral method is a useful method for solving nonlinear wave equations. However, it is not widely used because of the limitation of the periodic boundary condition. In this paper, the method is modified at its second step by avoiding transforming the wave height function into a frequency domain function. Thus, the periodic boundary condition is not required, and the new method is easy to implement. In order to validate its performance, the proposed method was used to solve the nonlinear parabolic mild-slope equation and the spatial modified nonlinear Schrodinger （MNLS） equation, which were used to model the wave propagation under different bathymetric conditions. Good agreement between the numerical and experimental results shows that the present method is effective and efficient in solving nonlinear wave eouations.

Effective Components of Dried Ginger in Warming Lung to Reduce Watery Phlegm and In vivo Tissue Distribution Based on the“Syndrome-Efficacy-Biological Sample Analysis”Method

Objective: This study aimed to investigate effective components of dried ginger(DG) in warming lung to reduce watery phlegm and in vivo tissue distribution on the syndrome of cold fluid retained in lung of rats with chronic obstructive pulmonary disease(COPD) by means of the "syndrome?efficacy?biological sample analysis" method and then to explore its meridian tropism. Methods: Wistar rats were given nasal drops of 200-μL lipopolysaccharide and smoke 30 min two times a day, then put the appropriate dose of ice water, and freeze for an hour to build model rats. On the 16 th day, the drug group was orally administered of DG(500 mg/mL) until the 30 th day. Blood samples and biological tissues were collected from the orbital venous plexus into heparinized hemostasis tubes at 5, 10, 15, 30, 45, 60, 90, 120, 180, 240, and 360 min after the last administration. Using ultraviolet-high-performance liquid chromatography(Waters, USA) method, the effective components were tested, and DAS 3.0 software(Mathematical Pharmacology Professional Committee of China, Shanghai, China) was used to analyze the results. Results: The compounds of DG entering into blood were 6-gingerol, 6-shogaol, and 8-gingerol. Tissue distribution analysis indicates that three active ingredients are widely present in the lung, spleen, kidney, liver, heart, large intestine, stomach, small intestine, and other organs of rats with COPD. Conclusions: 6?gingerol, 6?shogaol, and 8?gingerol belong to effective components of DG in curing the syndrome of cold fluid retained in lung of rats with COPD and mainly distributed in organs including the spleen, stomach, lung, kidney, liver, and heart.