【单选题】有一并联管路,如图所示,两段管路的流量,流速、管径、管一长及流动阻力损失分别为qv1,u1,d1,L1,∑hf1及qv2,u2,d2,L2,∑hf2若d1=d2进,L1=2L2,当两段管路中流体均作层流流动时,qv1/qv2=()。
【单选题】I can't find the book ________.
【单选题】有一并联管路,如图所示,两段管路的流量,流速、管径、管长及流动阻力损失分别为qv1,u1,d1,L1,Σhf1及 qv2,u2,d2,L2,Σhf2。若d1=2d2 ,L1=2L2。当两段管路中流体均作层流流动时,qv1/qv2为:
A.
mg src="http://p.ananas.chaoxing.com/star3/origin/2852d5995903cd1671c4845771741ebb.jpg">
【单选题】有一并联管路,如图所示,两段管路的流量、流速、管径、管长及流动阻力损失分别为qv1,u1,d1,L1,Σhf1及 qv2,u2,d2,L2,Σhf2。若d1=2d2 ,L1=2L2。当两段管路中流体均作层流流动时, u1/u2为:
A.
mg src="http://p.ananas.chaoxing.com/star3/origin/2852d5995903cd1671c4845771741ebb.jpg">
【单选题】—I hope you can get good grades in the final exam. —____________.
【单选题】He helped me and I hope I can do something for him_______.
【单选题】I hope that I can hear from you ________
【简答题】I hope we can have some snow this winter.
【简答题】已建成的世界上最大的潮汐发电站是法国朗斯河口发电站,总装机容量大约是 千瓦。