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The large-distance penetration capability of an annular-shaped charge under multipoint synchronous initiation was experimentally investigated. For different annular charge structures and different multipoint initiation settings, incident angle, collision type of detonation waves, and overpressure on the shaped charge’s liner at adjacent initiation points were analyzed using the detonation wave propagation theory. Furthermore, the shaped charge’s penetration capability at a standoff distance of 1–15 m from a 20 mm thick 45# steel plate (the target) was determined through penetration experiments. It was found that the annular cutter formed by the 500 mm diameter annular shaped charge (charge width: 100 mm) completely penetrated the target for a large distance, namely a distance of 150 times the charge width. The ratio of the width of the ring gap penetrated by the annular cutter to the liner’s initial radial width was about 1.07; this indicated that the annular cutter’s width was equivalent to the liner’s radial width for the above flight distance, which in turn implied that the annular cutter had superior circular degree. The annular cutter formed in the case of Mach reflection had better circular degree, integrity, and penetration capability than that formed by regular reflection.

Objective. To explore the effect and mechanism of ShiZhiFang on uric acid metabolism. Methods. 40 rats were divided into normal group, model group, ShiZhiFang group, and benzbromarone group. The hyperuricemic rat model was induced by yeast gavage at 15 g/kg and potassium oxonate intraperitoneal injection at 600 mg/kg for two weeks. During the next two weeks, ShiZhiFang group rats were given ShiZhiFang by gavage, and benzbromarone group rats were given benzbromarone by gavage. The serum uric acid, creatinine, blood urea nitrogen, XOD activity, urinary uric acid, urinary β2-MG, and histopathological changes were observed in the rats of each group after treatment. Results. The hyperuricemic model was established successfully and did not show the increase of serum creatinine and blood urea nitrogen. Compared with the model group, the serum uric acid, serum XOD activity, and urinary β2-MG were significantly decreased (p<0.05), and 24 h urinary uric acid excretion was significantly decreased (p<0.01) in ShiZhiFang group, whereas the two treatment groups were of no statistical significant in above indicators (p>0.05); renal histopathology showed that the lesions in two treatment groups were reduced compared to the model groups. The gene and protein expression of uric acid anion transporters rOAT1 and rOAT3 in the kidney was significantly higher than that in model group (p<0.01). Conclusion. The model is suitable for the study of primary hyperuricemia. The mechanisms of ShiZhiFang on uric acid metabolism in hyperuricemic rats may be involved in reducing the activity of serum XOD and promoting the transcription and expression of rOAT1 and rOAT3 in the kidney.