导程L<sub>0</sub>=8mm的丝杠的总质量为6kg,标称直径为40mm,则其转动惯量为()kg·mm<sup>2</sup>。
A、A.1200
B、B.480
C、C.120
D、D.48
A、A.1200
B、B.480
C、C.120
D、D.48
A、有两种比例,对于长试样L<sub>0sub>=8d<sub>0sub>,对于短试样L<sub>0sub>=5d<sub>0sub> B、有两种比例,对于长试样L<sub>0sub>=8d<sub>0sub>,对于短试样L<sub>0sub>=6d<sub>0sub> C、有两种比例,对于长试样L<sub>0sub>=10d<sub>0sub>,对于短试样L<sub>0sub>=6d<sub>0sub> D、有两种比例,对于长试样L<sub>0sub>=10d<sub>0sub>,对于短试样L<sub>0sub>=5d<sub>0sub>
A、L<sub>0sub>=5d<sub>0sub> B、L<sub>0sub>=2d<sub>0sub> C、L<sub>0sub>=10d<sub>0sub> D、L<sub>0sub>=15d<sub>0sub>
A、图示水平输液系统(A、B、C、D在同一水平面上),终点均通大气,被输液体相对密度δ=0.9,输送量为200t/h。设管径,管长,沿程阻力系数分别如下:
L<sub>1sub>=1km,L<sub>2sub>=L<sub>3sub>=4km;D<sub>1sub>=200mm,D<sub>2sub>=D<sub>3sub>=150mm;λ<sub>1sub>=0.025,λ<sub>2sub>=λ<sub>3sub>=0.030。
A、330kV及以上:总烃<10μL/L,H<sub>2sub><50μL/L,C<sub>2sub>H<sub>2sub>=0.1 B、330kV及以上:总烃<10μL/L,H<sub>2sub><100μL/L,C<sub>2sub>H<sub>2sub>=0.1 C、220kV及以下:总烃<10μL/L,H<sub>2sub><50μL/L,C<sub>2sub>H<sub>2sub>=0.1 D、220kV及以下:总烃<10μL/L,H<sub>2sub><100μL/L,C<sub>2sub>H<sub>2sub>=0.1
A、r<sub>1sub>=r<sub>2sub>=0,L<sub>1sub>=L<sub>2sub>=M=0 B、r<sub>1sub>=r<sub>2sub>=0,L<sub>1sub>=L<sub>2sub>=M=∞ C、r<sub>1sub>=r<sub>2sub>=∞,L<sub>1sub>=L<sub>2sub>=M=0 D、r<sub>1sub>=r<sub>2sub>=∞,L<sub>1sub>=L<sub>2sub>=M=∞
A、无上限值Q<sub>jsub>≥0.051Rbh<sub>0sub>,有下限值Q<sub>jsub>≤0.038R<sub>Lsub>bh<sub>0sub> B、有上限值Q<sub>jsub>≤0.051Rbh<sub>0sub>,无下限值Q<sub>jsub>≥0.038R<sub>Lsub>bh<sub>0sub> C、有上限值Q<sub>jsub>≤0.051Rbh<sub>0sub>,有下限值Q<sub>jsub>≥0.038R<sub>Lsub>bh<sub>0sub> D、无上限值Q<sub>jsub>≥0.051Rbh<sub>0sub>,无下限值Q<sub>jsub>≥0.038R<sub>Lsub>bh<sub>0sub>
A、在下图所示的铰链四杆机构中,各杆的长度分别为:l<sub>ABsub>=25mm,l<sub>BCsub>=55mm,l<sub>CDsub>=40mm,l<sub>ADsub>=50mm。
A、R×(L<sub>1sub>+L<sub>2sub>)mm3h-1 B、2R×L<sub>1sub>mm3h-1 C、2R×(L<sub>1sub>+L<sub>2sub>)mm3h-1 D、2R×(L<sub>1sub>—L<sub>2sub>)mm3h-1