从本章开始，介绍市场预测的有关内容。市场预测是在市场调查的基础上开展的，是 对未来市场的预计和估计。市场预测的类型、市场预测方法的种类都很多，将在其后各章 中加以介绍

本系统在一般情况下全新风运行，当外界气温过低或过高时可采用50 ％的回风。在取暖工况时，空气先进人一级空调器，流经滤器2和一 级加热器3，再经风机送人中间分配室5，由一级送风管11送至各舱室 布风器。一级送风的温度是通过单脉冲直接作用式温度调节器13控制 加热蒸汽量来调节

1 线性代数基本知识 线性空间: 定义在数域K上的向量集合{v1, v2, v3, …}=V. 在V中定义了加法和数乘两种运算. 设v1, v2, v3∈V,a,b,c ∈K, 向量的加法和数乘具有封闭性, 且满足下列条件:

一、含义 1、概念：序列相关（serial correlation）与自相关（autocorrelation） 通常不加区别，按时间（如在时间序列数据中）或者空间 （如在截面数据中）排列的观测值序列的成员之间的相 关

Food quality, including colour, texture, flavour and nutritional value, is of key importance in the context of food preservation and processing. Colour, texture and flavour refer to consumption quality, purchase and product acceptability whereas the nutritive values (i.e. vitamin content, nutrients, minerals, health￾related food components) refer to hidden quality aspects. In conventional thermal processing, process optimisation consists of reducing the severity of the thermal process in terms of food quality destruction without compromising food safety

Preventing the loss of vitamins and nutrients in foods is a paramount concern at all stages of food processing involving heating. One example of the critical need for retaining vitamins is to nourish hospital patients who require vitamins to recover from the stress of illness or surgery.1 This issue has invoked recent studies

‘Genetically modified food’ has become the object of a heated debate by con￾sumer activists and replaced irradiation’s leading role as a target. In this debate the term irradiation is frequently confused with radioactive contamination, espe￾cially after the Chernobyl accident. The allegation is made that the nuclear indus￾try needs food irradiation badly in order to find some use for the waste from

The modern frozen food industry was started by Clarence Birdseye in America in 1925. As a fur trader in Labrador Birdseye had noticed that fillets of fish left by the natives to freeze rapidly in arctic winters retained the taste and texture attrib￾utes of fresh fish better than fillets frozen in milder temperatures at other times of the year. Frozen foods were available before Birdseye’s pioneering innovations, but they were of poor and uncertain quality. Birdseye’s insight was that speed of freezing is crucial to retain quality and he was the first to develop machinery

The domestication of different grasses, all members of the monocotyledonous family Gramineae, was a seminal event in the history of mankind. The cultiva￾tion of these plants led to the generation of agricultural surpluses. These in turn enabled societies in different parts of the world to make the transition from a nomadic or semi-nomadic lifestyle to one based on communities living in per￾manent settlements

The taming of fire, permitting the thermal processing of vegetable foodstuffs in particular, extended enormously the number of natural products that could be used as foods by humans and gave a tremendous impulse to the extraordinary dif￾fusion and development of the human population in almost every region of the world (De Bry, 1994). Foodstuffs can be roughly divided in two classes, those that are or are not edible in their raw form. The most important naturally edible foods are meat and milk, which are heated mainly for eliminating dangerous microorganisms, and some fruits, used by plants to attract animals for diffusing