一、参考文献的类型 参考文献（即引文出处）的类型以单字母方式标识，具体如下：M——专著 C——论文集 N——报纸文章 J——期刊文章D——学位论文 R——报告 S——标准 P——专利A——文章

7-1含有长度为2a的型贯穿裂纹的无限大平板,材料为30 0CrMnSiNiA,在远离裂纹处受均匀 拉应力作用,如图7-11所示。已知材料的平面应变断裂韧度K1=(84MPa)m,裂纹的临界 长度a=8.98mm。试求裂纹发生失稳扩展时的拉应力σ值

7-1题7-1图(a)所示圆截面杆,两端承受一对方向相反、力 偶矩矢沿轴线且大小均为M的力偶作用。试问:在杆件的任一横

基于 1 0 0 B a s e - V G的L A N传输方式，它建立于令牌环网和以太网上，传输速率达 1 0 0 M b i t s / s，具有恢复力，而且实现的可能性很高。通常认为，其技术上比快速以太网更好， 可作为备用的方案，但市场上不太成功

Ladies and gentlemen: I have come to a decision which I felt I should tell you and all of my fellow American citizens, as soon as I was certain in my own mind and in my own conscience that it is the right thing to do. I have learned already in this* office that the difficult decisions always come to this desk. I must admit that many of them do not look at all the same as the hypothetical questions that I have answered f reely and perhaps too f ast on previous occasions

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}

The Synthetic Applications of Carbonyl Ylides David M. Barnes Evans Group Seminars, March 16, 1993 Reviews - Ylides Padwa, A.; Hornbuckle, S. F. Chem. Rev. 1991, 91, 263-309. Padwa, A.; Krumpe, K. E. Tetrahedron. 1992, 48, 5385-5483