As a result ,this pulse has steep sides and short duration ,in order of magnitude qual the time constant R'C.

1. 这句话应如何翻译呢？

所以 ，这种脉冲有陡峭内壁和短暂持续，按照相等的时间常数量级顺序顺序（排列）.

2. 这里有倒装的结构么？

这里没有倒装结构

3. equal是什么用法呢？

adj.  相等的，平等的; 平稳的; 势均力敌的; 胜任的;

继续跟踪回答如下：

in order of magnitude qual the time constant R'C.能分析下这句话的结构么，主谓宾什么的，而且找不到和主句之间的关系啊。

你的理解有误，以上不是句子，因此根本没有主语，谓语和宾语之说法：

In order of magnitude equal the time constant R'C 不是一个句子，而是一个介词短语作方式状语.

in order of 按照.....的顺序（排列）

 Manufacturers must list ingredients in order ofthe amount used.  

生产商必须按用量多少的顺序将成分列出。

 Write down (in order of priority) the qualities you'd like to have.  

（按照优先次序）写下你想具有的品质。

The guests were seated strictly in order of precedence.  

客人严格按照地位高低就座.

The tests in this book are arranged in order of difficulty.  

这本书的试题是按难易程度顺序排列的.

The texts should be graded in order of difficulty.  

课文要按难易程度编排.

The manager will interview the candidates in order of arrival.  

经理将按(到达)先后次序接见这些应征者.

Things should be taken up in order of priority.  

办事应有个先后次序.

The officers were listed in order of seniority.  

官员列名以职位高低为序.

The items are listed in order of importance.  

这些项目是按其重要性的顺序列出的.

现在明白了吗?如果不明白，请继续追问，如果明白了，请采纳，谢谢！