A、有一中等直径钢管并联管路,流过的总水量Q=0.08m<sup>3sup>/s,钢管的直径d<sub>1sub>=150mm,d<sub>2sub>=200mm,长度L<sub>1sub>=500m,L<sub>2sub>=800m。求并联管中的流量Q<sub>1sub>、Q<sub>2sub>及A、B两点间的水头损失(设并联管路沿程阻力系数均为λ=0.039)
mg src="https://img.ppkao.com/2019-04/liyunao/2019041416550665751.jpg" />
A、0.18m<sub>0sub>c<sup>2sup> B、0.25m<sub>0sub>c<sup>2sup> C、0.36m<sub>0sub>c<sup>2sup> D、1.25m<sub>0sub>c<sup>2sup>
A、设有一维晶体,其原子的质量均为m,而最近邻原子间的力常数交替地等于β和10β,且mg src="https://img.ppkao.com/2018-10/chenbin/2018101711144074235.jpg" />
A、k<sub>0sub>=k<sub>ssub> B、k<sub>0sub><k<sub>ssub> C、k<sub>0sub>>k<sub>ssub> D、反应系统不稳定,无法测得k<sub>ssub>
A、Δ<sub>rsub>H<sup>θsup><sub>msub>〈0,Δ<sub>rsub>S<sup>θsup><sub>msub>〈0 B、Δ<sub>rsub>H<sup>θsup><sub>msub>〉0,Δ<sub>rsub>S<sup>θsup><sub>msub>〉0 C、Δ<sub>rsub>H<sup>θsup><sub>msub>〈0,Δ<sub>rsub>S<sup>θsup><sub>msub>〉0 D、Δ<sub>rsub>H<sup>θsup><sub>msub>〉0,Δ<sub>rsub>S<sup>θsup><sub>msub>〈0
A、Δ<sub>rsub>H<sup>θsup><sub>msub>〉0,Δ<sub>rsub>S<sup>θsup><sub>msub>〉0 B、Δ<sub>rsub>H<sup>θsup><sub>msub>〉0,Δ<sub>rsub>S<sup>θsup><sub>msub>〈0 C、Δ<sub>rsub>H<sup>θsup><sub>msub>〈0,Δ<sub>rsub>S<sup>θsup><sub>msub>〈0 D、Δ<sub>rsub>H<sup>θsup><sub>msub>〈0,Δ<sub>rsub>S<sup>θsup><sub>msub>〉0
A、n=3,l=0,m=-1,m<sub>ssub>=1/2 B、n=3,l=1,m=1,m<sub>ssub>= -1/2 C、n=4,l=-2,m=0,m<sub>ssub>=1/2 D、n=4,l=1,m=2,m<sub>ssub>=-1/2