影响土壤比重的因素: 土壤比重仅仅取决于土壤固相颗粒的物质组成。 Since a large portion of most soils is composed of particles derived from quartz minerals, the particle density of most soils is near 2.6 g/cc which is the density of quartz. Variations in the particle density are due to the presence of heavier minerals like iron oxides or lighter organic components

Ch. 23 Cointegration 1 Introduction An important property of (1) variables is that there can be linear combinations of theses variables that are I(O). If this is so then these variables are said to be cointegrated. Suppose that we consider two variables Yt and Xt that are I(1) (For example, Yt= Yt-1+ St and Xt= Xi-1+nt.)Then, Yt and Xt are said to be cointegrated if there exists a B such

第二章作物需水量和灌溉用水量 第一节作物需水量 1、农田水分消耗的主要途径 ·A植株蒸腾(transpirarion) ·B棵间蒸发(evaporation) ·C深层渗漏

第8章密钥管理习题 1.密钥管理为什么重要? 2.密钥的种类是如何区分的?有哪些分类标准? 3.对线性同余算法Xn+1= aXn mod24,问:a)该数列产生的最大周期是多少?

CHAP2生态学基础 2-1生态学基础 一、生态学与生态 1.生态学(Ecology): A.传统定义:研究生物与其生活环境相互关系的学科。(侧重于植物、动物)

一、单项选择题 1、人生价值的根本内容是以()的关系为实际内容的人与人之间的价值关系 A、自我与他人 B、索取与享受 C、劳动与创造 D、贡献与索取

第一单元同步强化测试 I. Choose the one that best completes the sentence. 1 his sister, Jack is quiet and does not easily make friends with others. A. Unlike B. Liking C. Alike D. Dislike

Intensive stud Lighten Your Load and save Your life Para.1 If you often feel angry and overwhelmed, like the stress in your life is spinning out of control, then you may be hurting your heart. Para. 2 If you dont want to break your own heart, you need to learn to take charge of your life where you can-and recognize there are many things beyond your control

4-1 Momentum Impulse Momentum Theorem动量冲量动量原理 4-2 Conservation of Momentum动量守恒定律 4-3 Collision碰撞 4-4 Angular Momentum of a Particle and Conservation of Angular Momentum质点对定点的角动量角动量守恒定律

第三章平面任意力系 3.1已知图(a)力系中,F1=150N,F2=200N,F3= 300N,F=F=200N; 求力系向点O简化的结果;合力的大小及其与原点的距 离