在金属材料中,声发射现象一般来源于()、()、()、()以及()。
参考答案:金属塑性变形;位错运动;马氏体转变;裂纹形成和发展;磁性效应
HIV阳性患者近来咳嗽,胸闷,胸片检查发现病变,CT检查如图,最可能的诊断为()
A.肺淋巴瘤
B.卡波济肉瘤
C.双肺感染
D.间质性肺炎
E.肺癌
A VLCC (100,000 DWT+) with a 30,000 Shaft Horsepower Steam Turbine is slow to respond to engine movements and has less stopping power than normal ships because it has a().
A.bigger propeller
B.smaller power to weight ratio
C.smaller propeller
D.larger power to weight ratio