1.子式:在A中,选取k行与k列,位于交叉处的k2个数按照原来的相对位置构成k阶行列式,称为A的一个k阶子式,记作Dk对于给定的k,不同的k阶子式总共有C个 2.矩阵的秩:在A中,若 (1)有某个r阶子式D≠0; (2)所有的r+1阶子式D+1=0(如果有r+1阶子式的话) 称A的秩为r,记作 rankA=r,或者r(A)=r.规定: rankO=0性质:(1) rankA min{m,n}

一、解释：（20%） 1、单位转速 H nD n 1 11 = 表示当 D1=1m,H=1m 时水轮机具有的转速。 2、飞逸转速 当水轮机发电机组突然丢弃全部负荷时，如调速机构失灵或其它原因使导水机构 不能关闭，机组转速将迅速升高并达到某一最大值，该转速称作飞逸转速

1 . The chara cte ristics of the n euronal cell Wha t would come to your mind as a definition? It is a cell of the brain: that is not correct, it is more widely spread: CNS = brain + spinal cord, SN P, ente ric s ystem. It is an exc itable cell: it is tr ue but this property is s hared with other cells. Muscles: striated musc le, heart. And other cells too such as endocrine cells present an exc itabilit y that is the property to gene rate action

Responsible for reliable transmission of packets over a link – Framing: Determine t he star t and end of packets (sec 2.5) – Error Detection: Determine w hen a packet contains errors (sec 2.3) – Error recovery: Retransmissio n of packets containing errors (sec 2..4)

17.1 Digital Image Processing Image Capture. Point Operations Image Enhancement. Digital Purdue University Image Compression. Reconstruction. Edge Detection.Analysis Charles A.Bouman and Computer Vision Purdue University 17.2 Video Signal Processing Sampling. Quantization. Vector Quantization.Video Sarah A. Rajala Compression Informatin Preserving Coders.Predictive North Carolina State University Coding. Motion-Compensated Predictive Coding- Transform Coding. Subband Coding HDTV. Motion Estimation N.K.Bose

禽流感( Avian Influenza,AI)是由A型流 感病毒引起的家禽和野禽的一种烈性传染病, 给养禽业造成巨大损失,我国农业部和国际 兽医局都将其定为A类传染病。以往认为禽流 感病毒(Avian Influenza Virus,AIV)对人群无 致病力,但1997年香港报道了首例因感染 H5N1亚型AIV致死人事件后,近年及最近又 有多例人感染AIV发病,甚至死亡的报道。由 此可以看出,禽流感也具有重要的公共卫生 意义

设矩阵A∈Rn,如果存在数入∈C及非零向量x∈C满足方程 Ax∈x,则称λ为矩阵A的一个特征值,称为矩阵A的相应于特 征值λ的特征向量。为简单起见,下称,x为矩阵A的一特征对。 特征值的计算,直接从特征方程()=det-A)=0出发会遇到很 大困难,当n稍大一些,行列式展开本身就很不容易,随后是高次代数 方程求解。因此,矩阵特征值的求解,主要是数值解法

I Consider the graph shown in Fig. 15-15. Denote the tree made up of b 6, bs, and b, by t (a)Find all the fundamental loops of this graph corresponding to T (b) Find all the fundamental cutsets of this graph corresponding to t (c) Write the incidence matrix of this graph choose n 4 as the datum

We consider each term of the Fourier aeries representing the voltage as a single source. The equivalent impedance of the network at no is used to compute the current at that harmonic. XL(n) =noL and XC() =-1/noC The sum of these individual responses is the total response i

2-7强度条件安全系数许用应力 拉(压)杆的强度n件 Strength Condition of Axial Forced Bar 由公式(o=Nmax/A)求得拉(压)杆的最大工作应力后, 并不能判断杆件是否会因强度不足而发生破坏。只有把杆 件的最大工作应力与材料的强度指标联系起来,才有可能对此作出结论