Experimental study of the underwater plasma based on the phased array vibrator system
In this paper, a set of underwater plasma vibroseis system was developed, which included three big systems, i.e. charge system, discharge system and trigger system. At the same time, an experimental platform was set up through tketornix digital oscilloscope, seismic detector and desktop computer for collecting and processing data. On this basis, three working stages (breakdown, detonation and spread) of the underwater plasma were carried out the experimental research and summary. By experiment, the electrical properties of the underwater plasma were investigated under the different electrode materials, different number of electrodes, different voltages, different electrode gap spacing conditions. By using the ORIGIN data analysis software, the plasma channel resistance and the trend of the change of discharge power in time domain were obtained. It laid a foundation for choosing the optimal transducer structure and its material. In addition, the process of pulsed discharge in water was analysed. By comparing and summarizing, it found that the efficiency of corona discharge significantly is higher than that of arc discharge. This research provides references for the design of the plasma source in water.
Development of a phased array sparker
Most of the metallogenic belt of metal ores are in the orogenic belt, the surface and subsurface geological conditions are very complicated, the conventional seismic exploration techniques can not meet the requirements of the seismic exploration, such as dynamite source, vibrator, airgun and the sparker. A phased array sparker was developed for this potential application, which mainly consists of nine modular sparker, a programmable pulse generator and nine ground transducers which can be easily inserted into the ground. Each sparker includes an isolated diode, a capacitor with a stored energy of 500 J and a thyristor discharge switch. The programmable pulse generator was used to control the discharging time of each sparker. The transducer used to convert the electric energy into the seismic wave energy has a hermetical discharging chamber filled with salt solution. The preliminary tests were presented.
Protective effect of ginsenoside Re on acute gastric mucosal lesion induced by compound 48/80
The protective effect of ginsenoside Re, isolated from ginseng berry, against acute gastric mucosal lesions was examined in rats with a single intraperitoneal injection of compound 48/80 (C48/80). Ginsenoside Re (20 mg/kg or 100 mg/kg) was orally administered 0.5 h prior to C48/80 treatment. Ginsenoside Re dose-dependently prevented gastric mucosal lesion development 3 h after C48/80 treatment. Increases in the activities of myeloperoxidase (MPO; an index of neutrophil infiltration) and xanthine oxidase (XO) and the content of thiobarbituric acid reactive substances (TBARS; an index of lipid peroxidation) and decreases in the contents of hexosamine (a marker of gastric mucus) and adherent mucus, which occurred in gastric mucosal tissues after C48/80 treatment, were significantly attenuated by ginsenoside Re. The elevation of Bax expression and the decrease in Bcl2 expression after C48/80 treatment were also attenuated by ginsenoside Re. Ginsenoside Re significantly attenuated all these changes 3 h after C48/80 treatment. These results indicate that orally administered ginsenoside Re protects against C48/80-induced acute gastric mucosal lesions in rats, possibly through its stimulatory action on gastric mucus synthesis and secretion, its inhibitory action on neutrophil infiltration, and enhanced lipid peroxidation in the gastric mucosal tissue.