【单选题】如涡流探伤的激励频率降低,而场强不变,则金属棒材中心的涡流密度会()。
【单选题】如涡流探伤的激励频率增加,而场强不变,则试件表面的涡流密度会:
【简答题】要求,围绕二语习得理论课后调研已发表的论文,研读之后,以PPT形式+录音的形式进行汇报,按学习委员安排的汇报顺序,周日24点前提交给老师邮箱: 1074791327@qq.com;于此同时有上传条件的可以通过电脑上传作业。
【单选题】When the desired rudder angle is attained by a typical double mm electro-hydraulic steering gear, the _____.
A.
ram relief valves bypass oil to stop rudder movement
B.
six-way valve shifts to the neutral flow position
C.
steering pump electric motor is de - energized by the transfer switch
D.
follow-up gear takes the hydraulic pump off stroke