AN EXPERIMENTAL INVESTIGATION OF TURNING-POINT CONVERGENCE-ZONES IN A DEEP SOUND CHANNEL IN THE SOUTH CHINA SEA

in October 1983,an experiment was carried out to investigate the characteristics of turning-point convergence-zones and of underwater sound propagation in a deep sound channel in the SouthChina Sea by using explosive sound sources.In this paper,we present the experimental results forthe source depths of 200 m and 500 m.By using the theory on the turning-point convergence-zoneand parabolic approximation,the measured data are analysed.For low-frequencies the measuredpositions and convergence-gains of zones coincide with calculated results quite well.     

0—100A高稳定度超导磁体电源

迄今为止国内生产的超导磁体电源大都采用六十年代的电子线路和分立器件,其励磁电流的升降还都沿用伺服马达的电路,因此整个电源结构繁复、体积庞大、调场速度由马达控制。我们参照文献[1-3]设计和研制了一个电路简单、调场方便的高稳定性超导磁体电源,设计和达到的性能指标如下:进线220V单相供电;电流可调范围0—100A;输出电压0—4V;功率管风扇冷却;电流调整率(?)3.3×10~(-5)(外电源220V±22V);电流     

南海深海声道中反转点会聚区的实验研究

本文介绍了1983年10月在南海深海声道中进行的一次综合性爆炸声传播实验的结果,目的在于研究水下声道中反转点会聚区的特性。用反转点会聚区的渐近理论以及P-E法对声场进行了计算,实验得到的会聚区位置及会聚增益与计算结果很好符合。