BH积曲线(磁能积曲线)
参考答案:
以永磁体的退磁曲线上所对应的各BH积值为横坐标,m对应点的磁通密度B为纵坐标,求得的曲线。
引起光感性药疹的药物常见于()。
A.补骨脂
B.喹诺酮类
C.青霉素类
D.疫苗
E.磺胺类
“It is declared that this shipment does not contain any wood packing materials.”与这句话意思接近的是( )。
A.We declare that no wood packing material was used in this shipment
B.No declaration was made whether wood packing materials had been used or not
C.If you don' t make any declaration,we will not use any wood packing material
D.We will not use any wood packing material since you have provided us a declaration of no-wood packing material