本章主要介绍化工中常用的流体输送机械的基本结构、工作原理和特性,以便能够依据流体流动的有关原理正确地选择和使用流体输送机械。具体地说，就是根据输送任务正确地选择输送机械的类型和规格，决定输送机械在管路中的位置,计算所消耗的功率等，使输送机械能在高效率下可靠地运行。

本章着重讨论流体流动过程的基本原理及流体在管内的流动规律，并运用这些原理与规律去分析和计算流体的输送问题。

贴贴专栏下的单词表，来源国家地理。

In modern society, it is possible to go shopping, work and communicate via the Internet without face-to-face contact with one another. To what extent do you think this is a positive or negative development?

Today, many people put their personal and private information online (address, phone number, and credit card number) to facilitate everyday activities, such as banking, shopping, and socializing. Is this a positive or negative development?

More and more people no longer read newspaper or watch TV programs to get news. They get news about the world through the internet. Is this a positive or negative development?

Being cautious about false information online

话题下的常用词汇、短语 Expressions 翻译 world muti-polarization 世

《马克思主义基本原理概论》2023复习文档

《马克思主义基本原理概论》2023复习文档

《马克思主义基本原理概论》2023复习文档

“你只能了解你驯养的东西。”狐狸说，“人类不再有时间去了解事情了，他们总是到商店里买现在的东西。但是，却没有一家商店贩卖友谊，所以人类没