一、分布 有一定种稻历史的地区就有水稻土的分 布。我国水稻土大约占全国耕地面积的 1/5,主要分布在秦岭、淮河以南地区。 我省水稻土占全省耕地总面积的83%, 是我省最重要的粮食和经济作物的生产 基地

频率特性是控制系统在频域中的一种数学模 型,是研究自动控制系统的一种工程方法 系统频率特性能间接地揭示系统的动态特性和 稳态特性,可简单迅速地判断某些环节或参数对系 统性能的影响,指出系统改进方向 频率特性可以由实验确定,这对于难以建立动 态模型的系统来说,很有用处

一、接触器的定义和基本特点 接触器是指用于频繁地、远距离地、接 通和分断带有负载的主电路或大容量控 制电路的自动切换电器。其主要控制对 象是电动机,也可用于控制其它电力负 载,如电热器、照明灯、电焊机、电容 器组等

Determination of the relative movement of the two walls from the tension joints

TERMINOLOGY FOR DISPLACEMENT a is the rake angle

Main Bedding Types Bedding Shape level bedding ripple bedding Main Types of plate laminae

CONSTRUCTION OF VERTICAL SECTION 1 Select the location of the section and draw a section line (usually perpendicular to the strike of the main structures), right-hand end is its more easterly end 2 Draw a topographic profile along the line of section. Determine the base line on the squared

Review Show the homework and note book on your desk Practise measurement of attitude of planes and lines in the models

Determination of the top sur faces of the beds from the scour surfaces

Chapter 2 Primary Sedimentary Structures Main types of bedding Determination of younger direction of beds from primary structures Types of stratigraphic break Angular unconformity Soft sedimentary structures