2.1 Introduction: the role of packaging in the food chain Packaging has a significant role in the food supply chain and it is an integral part both of the food processes and the whole food supply chain. Food packaging has to perform several tasks as well as fulfilling many demands and requirements. Traditionally, a food package makes distribution easier. It has protected food from environmental conditions, such as light, oxygen, moisture, microbes, mechanical stresses and dust. Other basic tasks have been to ensure adequate labelling for providing information e.g., to the customer, and a proper convenience to the consumer, e.g., easy opening, reclosable lids and a suitable dosing mechanism. Basic requirements are good marketing properties

定理7.3.1设矩阵A∈Rn,且非奇异,则一定存在正交矩 nxn 阵,上三角矩阵R,使 A=OR (7.3.2) 且当要求R的主对角元素均为正数时,则分解式(7.3.2)是唯一的。 证明存在性有矩阵A的非奇 Householder异性及变换矩 阵的性质(3)知,一定可构造n-1个H矩阵:H1,H2,…,Hn-1使 A+1=HA(k=1,2,…n-1)

void TSMatrix_add(TSMatr ix, TSMatr, TSMatrix&c)/三元组 表示的稀疏矩阵加法 { C. mu=A. mu; C. nu=A. nu; C. tu=; pa=1;pb=1;pc=1; for(x=1x<=A.mu;x++)//对矩阵的每一行进行加法 while(A. data [pa]. i