若存储器总线宽度为64位，工作频率为1333MT/s，即每秒传输1333M次，则该存储器总线的带宽为（）GB/s（结果至少取两位小数）。

临床应用型1．5T MRI设备的常规切换率达( )。

A．60mT／m／s以上

B．80mT／m／s以上

C．100mT／m／s以上

D．120mT／m／s以上

E．140mT／m／s以上

有两台三相笼型电动机M12和M2。今要求M1先起动，经过5 s后M2起动；M2起动后，Mt立即停车。试用PLC实现上述控制要求，画出梯形图，并写出指令语句表。

调制信号为f(t)=cosω_mt-sinω_mt，频偏常数K_FM=8×10³π(rad·s^-1)/V，ω_m=200πrad/s，求调频信号的最大频偏和带宽。

有关梯度切换率的叙述，错误的是()

A.是指单位时间及单位长度内梯度磁场强度变化量

B.常用每秒每米长度磁场变化毫特斯拉量(mT/M.S)

C.切换率越高表明梯度磁场切换越快

D.梯度越高也即梯度线圈通电后梯度磁场达到预设值所需的时间越短

E.是指单位时间内的梯度磁场强度变化量

A．To tell him that the woman would meet him at his office.

B．To ask him for an appointment.

C．To ask him what time the woman's appointment was.

D．To get a prescription for the woman.

Which of the following is NOT truebout mth teching in the U. S. now N. C. T.M. strtWhich of the following is NOT truebout mth teching in the U. S. now N. C. T.M. strts to emphsize on the bck-to-bsicspproch. B．Mth stndrds for students in ech sttere over diversified. C．mericn kids lost interntionl tests to their peers in Singporend Belgium. D．mericn kidsre overburdened with drillsnd times tbles recitls.

A．N．

C．T．M． starts to emphasize on the back-to-basics approach．

B．Math standards for students in each state are over diversifieD

C．American kids lost international tests to their peers in Singapore and Belgium．

D．American kids are overburdened with drills and times tables recitals．

WES型高坝，坝高P=107．0m，最大水头Hmax=11．0m，设计水头取Hd=0．85 Hmax，下游坝面直线段坡度mt=0．75。决定采用垂直的上游坝面，若通过的最大流量Qmax=3100m3／s，堰孔总净宽B为多少?若每孔定为b=10m，应设多少孔?已知闸门为弧形，闸墩和边墩头部都是圆形，墩厚d=2．0m，上游引渠宽B0=410m。