钢管订购和运输优化模型 要铺设一条A1→A2→…→A13的输送天然气的主管道,如图一所示(见反 面)。经筛选后可以生产这种主管道钢管的钢厂有S1,S2,S图中粗线表示铁 路,单细线表示公路,双细线表示要铺设的管道(假设沿管道或者原来有公路,或 者建有施工公路),圆圈表示火车站,每段铁路、公路和管道旁的阿拉伯数字表示 里程(单位km) 为方便计,1km主管道钢管称为1单位钢管

宽平稳过程 定义设随机过程Xr={x(t),t∈T}X(t)<,(即Xr为二阶矩过程)若 EX(t)=m为常数,Cov((t),x(s)=[(x(t)-m)((s)-m)=r(t-s) 则称Xr为宽平稳过程或协方差平稳过程

Unit 1 My First Job Unit 2 American Homes and British Homes Unit 3 What is in a Name? Unit 4 Doing Away with the King's English Unit 5 England as seen by Americans Unit 6 The First Day at School Unit 7 Computers Unit 8 The Missing Monarchs Unit 9 The Risks of Life Unit 10 Words can Give You Power Unit 11 The Transaction Unit 12 The Message Behind the Smile Unit 13 A Delightful Village Unit 14 The Mystery of the White Gardenia Unit 15 For or Against Smoking in Public Places Unit 1 Someone Waiting Unit 2 Football Unit 3 The Snake Bite Unit 4 He was My Father Unit 5 The English Countryside Unit 6 Suffering to Be Beautiful Unit 7 Waiting for a Call Unit 8 Secret Messages to Ourselves Unit 9 All That' s Happening in the Music World Unit 10 Teenager's Nightmare the English Countryside Unit 11 Understanding Your Owner Unit 12 Transforming Mars Unit 13 The Mud-backs Unit 14 The Japanese Ageing Suit Unit 15 Have You Seen the Tree? Unit 1 My Father Unit 2 Why My Great-uncle Gave up the Ministry

3-1质量m=10kg的物体在力F=30+4N的作用下沿x轴运动,试求(1)在开始2s内此力的冲量l:(2)如冲 量F=300Ns,此力的作用时间是多少?(3)如物体的初速v1=10m/s,在6.86s时,此物体的速度n2为 多少?

例4.1串联排队系统 某汽车加油站,汽车以间隔时间为100/10s(均匀分布) 到达加油站,排队加油,加油服务时间为80/8s,加油后去 交费站,排队等待交费,交费时间为50/30s

4.5用拉普拉斯变换法分析电路、s域的元件模型 4.6系统函数H(s) 4.7系统函数的零、极点分布决定时域特性 4.8系统函数的零、极点分布决定频域特性 4.10全通网络和最小相移函数的零极点分布 4.11线性系统的稳定性 本章要求

1 已知质点沿 x 轴作直线运动，其运 动方程为： ，式中 x的单位 为m，t 的单位为s．求：（l）质点在运动 开始后4.0s内位移的大小；（2）质点在该 时间内所通过的路程；（3）t=4s时质点的 速度和加速度．

Into I. Basic listening practice 1. Script w: What's that? Is it a toy? Did it get chewed by a dog? M: Hey, that s my mascot! My uncle gave it to me when I was five, and it's been with me ever since. It brought me luck in all my college exams. I can t bring myself to

profit maximization Contain: Some definition -Isoprofit curve -Demand function and it's properties supply function and it's properties -Profit function and it's properties lecture 2 for Chu Kechen Honors College

Uints I. Basic listening practice 1. Script W: I bought a camera from your store. Here's my receipt. I know it's just warranty period, but the camera hasn't worked properly for some time, and now it's not focusing at all. M: We're sorry you've has problem with one of our cameras. I t seems that the camera has suffered some damage, but you've been a regular customer, and wed