A、设双口网络[S]已知,终端接有负载Z1,如下图所示,求输入端的反射系数。<br /> <img src="https://img.ppkao.com/2018-09/wenxueying/2018091710115385614.jpg" />
A、已知各分部工程的价值系数vi,功能系数fi,成本系数ci,如下表所示,试用最合适区域法选择价值工程分析对象。<br /> <img src="https://img.ppkao.com/2018-07/wenxueying/2018073015165754379.png" />
A、设X=(X1,…Xp)′的协方差阵(p×p)为<img src="https://img.ppkao.com/2018-10/wangjing/2018100917075243497.jpg" />,0
br>证明:λ1=σ2[1-ρ(1-ρ)]为最大特征根,其对应的主成分为<img src="https://img.ppkao.com/2018-10/wangjing/2018100917073511194.jpg" />
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A、试计算如图所示弯曲件的毛料展开长度。(已知位移系数K=0.39)<br /> <img src="https://img.ppkao.com/2019-04/wangjue/2019041414463434363.jpg" />
A、A.AB<br /> B.<img src="https://img.ppkao.com/2019-04/wangjue/2019041612322333927.jpg" /><br /> C.<img src="https://img.ppkao.com/2019-04/wangjue/201904161232269440.jpg" /><br /> D.AB+C
A、试求如图所示两并联管的流量各为多少?已知总流量q=25L/min<img src="https://img.ppkao.com/2019-04/wuacheng/2019041916385512796.jpg" />假设沿程压力损失系数<img src="https://img.ppkao.com/2019-04/wuacheng/201904191639131301.jpg" />则并联管路中的总压力损失等于多少?<br /> <img src="https://img.ppkao.com/2019-04/wuacheng/2019041916392844008.jpg" />
A、A.<img src="https://img.ppkao.com/2018-04/zhouyun/2018041117140637692.jpg" /><br /> B.<img src="https://img.ppkao.com/2018-04/zhouyun/201804111714091678.jpg" /><br /> C.<img src="https://img.ppkao.com/2018-04/zhouyun/2018041117141476512.jpg" /><br /> D.<img src="https://img.ppkao.com/2018-04/zhouyun/2018041117142045280.jpg" /><br /> E.<img src="https://img.ppkao.com/2018-04/zhouyun/2018041117142344778.jpg" />