[Investigation on the spectrum of complex self-organized plasma photonic crystal].

A complex plasma photonic crystal (PPC) was obtained by self-organization of filaments in air dielectric barrier discharge using two planar water electrodes. The PPC structure consists of many square sublattices, and each sublattice is composed of large spots, two kinds of small spots and lines, corresponding to thick plasma columns, two kinds of thin plasma columns, and plasma slices, respectively. By using the optical emission spectrum method, the electron densities and molecular vibration temperatures at different positions of the PPC were studied. The electron densities were compared by comparing the broadenings of Ar I (2P2-->1S5) spectrum line, and the molecular vibration temperatures were calculated by the spectrum line of nitrogen band of second positive system (C3Πu-->B3Πg) . It was found that the electron densities and molecular vibration temperatures at different positions are both different, showing that the plasma states at different positions are different. The descending order of the electron density is: thin plasma columns around the thick plasma columns, thick plasma columns, plasma slices, and thin plasma columns at junction of plasma slices. The descending order of the molecular vibration temperature is: thin plasma columns at junction of plasma slices, plasma slices, thick plasma columns, and thin plasma columns around the thick plasma columns, which is opposite to that of the electron density. So, the electron densities and the molecular vibration temperatures in different positions of the PPC show the opposite changing trend. As the refractive index of plasma is dependent upon the electron density, the thick plasma columns, two kinds of thin plasma columns and plasma slices in this PPC have different refractive indexes. Together with the surrounding area where no discharges occur, in which the refractive index is also different from the discharging areas, the complex PPC can be seen as a self-organized periodic structure with five different refractive indexes. The PPC has the advantages of being obtained easily, having structural diversity, and being analyzed simply, which may lead to wide applications in many scientific and technical areas.

[Investigation of plasma parameters of the square pattern with two kinds of spatiotemporal symmetry in dielectric barrier discharge].

Two kinds of square patterns with different spatiotemporal symmetry were observed in dielectric barrier discharge, and their plasma parameters were measured by using optical emission spectra. It was found that the spatiotemporal symmetry of the square pattern at lower gas pressure is different from the one at higher gas pressure. Six spectral lines in the emission spectrum of the N2 second positive band were chosen to estimate the vibrational temperature, and the ratio of I391.4/I394.1 was used to represent the average electron energy. The excitation temperature was determined by the ratio of I763.2/I772.1. Furthermore, the width and shift of Ar I 696.54 nm were used to estimate the electron density. The results show that the vibrational temperature, excitation temperature and electron energy of the square pattern at lower gas pressure are higher than those at higher gas pressure, while the electron density is lower than that at higher gas pressure.

[Clinical treatment of 29 cases of acne of "yin-deficiency-inner heat type" by suspended moxibustion].

OBJECTIVE: To observe the clinical effect of moxibustion therapy for 29 cases of yin-deficiency type acne. METHODS: In this clinical trial, 56 cases of acne patients with yin-deficiency-inner heat type were enrolled. These patients were randomly divided into moxibustion group (treated by suspended moxibustion, n = 29) and control group (treated by acupuncture, n = 27). In addition, patients of the two groups were also treated by local purulent discharge and skin disinfection, once a week, 4 times a month, 8 times altogether. Both suspended moxibustion and acupuncture interventions were performed once every other day, 3 times a week and 3 months altogether. The therapeutic effect was evaluated by skin lesion score and patients' constitution score. RESULTS: Of the patients in the moxibustion and control groups, 2 and 1 was cured (the acne subsided above 90% and symptoms disappeared), 14 and 6 experienced marked improvement (the acne subsided by 60%-90% and symptoms were obviously relieved), 10 and 15 were effective (the acne subsided by 30%-59% and symptoms were relieved), 3 and 5 invalid (the acne subsided by below 30% and symptoms were worsen), respectively. The effective rate of the moxibustion group was significantly higher than that of the control group (P < 0.05). Following the treatment, the skin lesion score and yin-deficiency constitution score were significantly decreased in comparison with pre-treatment in the same one group (P < 0.05), and those of the moxibustion group were remarkably lower than those of the control group (P < 0.05). CONCLUSION: Suspended moxibustion is effective in improving both skin lesion and yin-deficiency constitution in acne patients with yin-deficiency-inner heat type.

[Study on stable process of hexagon pattern in dielectric barrier discharge by optical emission spectra].

The effect of plasma parameters and excited states on the stable process of the hexagon pattern in a dielectric barrier discharge was studied by using optical emission spectra. It was found that the diameter of the discharge filament increases, the pattern gets more stable, and the color of the pattern changes from purple to gray with the increase in the voltage in dielectric barrier discharge in argon and air mixture. It indicates that the plasma excited states and parameters may be changed. To this end, the relative intensity of N2 and Ar spectral lines with respect to Ar I 763.51 nm, the molecular vibration temperature, and the electron excitation temperature were measured with the change in the applied voltage. The results show that the relative intensity of N2 spectral lines decreases and that of Ar spectral lines increases with the increase in the voltage. And both the molecular vibration temperature and the electron excitation temperature increase. These phenomena indicate that the electron energy increases with the increase in the voltage. The increase of the stimulated argon atoms excited by higher energy electron leads to the increase in the diameters of the discharge filaments. Correspondingly, the areas of the wall charges deposited on the dielectric increase, which results in the enhancement of the interactions between filaments, and therefore the hexagon pattern becomes stable.