A plasma jet equipped with dielectric barrier discharge (DBD) is developed to generate diffuse air plasma with fairly large gap and cross sectional area. The diffuse air plasma has two discharge modes under different gap widths from the nozzle to the ground plate electrode. For large gap width, a diffuse plume fills the whole space between the nozzle and the plate electrode after coaxial DBD is ignited when the applied voltage reaches a certain value. Rather than diffuse plasma plume, a bright plasma column bridges the nozzle and the plate electrode with further increasing the applied voltage under small gap width. By optical and electrical measurement, results show that the macroscopically diffuse discharge in air is obtained by the superimposition of radially distributed streamers that appear at different cycles of the applied voltage, and the bright plasma column belongs to atmospheric pressure glow discharge. The molecular vibrational temperature and the gas temperature are given as functions of the peak value of the applied voltage.

A plasma column with a length of about 65 cm is generated in the upstream region of a plasma jet using dielectric barrier discharge configurations. The effects of experimental parameters such as the amplitude of the applied voltage and the driving frequency are investigated in aspects of the plasma column by the optical method. Results show that both the plasma length and the propagating velocity, as well as the discharge current, increase with the increase in the applied voltage or its frequency. The discharge mechanism is analysed qualitatively based on streamer theory, where photo-ionization is important. Furthermore, optical emission spectroscopy is used to investigate the electric field intensity of the upstream region.

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Cold plasma generated by atmospheric air discharge has wide application prospect in industry because it does not need vacuum equipment and mass production is possible. In this paper, a stable uniform discharge is generated in open air by a plasma needle. Discharge mechanism is investigated by optical method, and plasma parameters are given by the spatially resolved measurement of emission spectrum from the discharge. Results show that the discharges have two modes. One is a corona discharge mode and the other is plasma plume mode. In the stable plasma plume mode, a strong emission area and a weak emission one can be distinguished from each other. The development velocity of the weak emission area is much faster than that of the strong emission area. Furthermore, the electron energy and the plasma density in the weak emission area are also bigger than those in the strong emission area. Therefore, the discharge in the strong emission area is dominated by Townsend mechanism, while that in the weak emission area is dominated by streamer discharge. Gas temperature and vibration temperature are also studied in this paper. The experimental results are of great importance to the industrial applications of atmospheric pressure discharge.

For student entrepreneurs with insufficient business experience, they need to hold an open attitude to maintain their competitive advantages in the market and improve their entrepreneurial performance via recruiting talents and creating sales channels using various network resources and advanced IT development technologies. Although field scholars in the world have conducted a lot of research on the evaluation of college students’ innovativeness and entrepreneurship, the differences in study regions, education modes, education concepts, and measurement tools have resulted in large deviations in the evaluation results of different study regions and schools. For this reason, this paper aims to find out the influence mechanism of the improvement of college students’ network ability on the scale of Entrepreneurial Cooperation Network (ECN). At first, the network ability of college students and their fitness degree to harmonious entrepreneurship were measured and analyzed; then, the influence of network ability improvement on ECN scale was studied empirically, and the model regression estimation results were given, which has verified that the psychological quality of student entrepreneurs has a moderating effect on the relationship between their network ability and the scale of ECN they created.