对给定的方程进行左对齐

对给定的方程进行左对齐

问题:我怎样才能证明(在左边)给定的等式?

平均能量损失

\documentclass[12pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[width=1.00cm, height=1.00cm, left=1.00cm, right=1.00cm, top=1.00cm, bottom=1.00cm]{geometry}
\usepackage{amssymb}
\usepackage{mathtools}
\usepackage{amsthm}
\begin{document}
\begin{equation}
    \begin{split}
        \dfrac{\partial T}{\partial t}+\left(u\,\frac{\partial T}{\partial x} + v\,\frac{\partial T}{\partial y}\right)
        &=  \left(\dfrac{k_{2}}{\rho\,c_{p}}\right)\,\dfrac{\partial^2 T}{\partial y^2}+\left(\dfrac{\mu+\kappa}{\rho\,c_{p}}\right)\,\left(\dfrac{\partial u}{\partial y}\right)^2 
        + \left(\dfrac{\sigma B_{0}^2}{\rho\,c_{p}}\right)\;u^2 \\[1ex]
        &\qquad\qquad\quad\quad\quad\qquad\qquad  -\dfrac{1}{\rho\,c_{p}}\;\dfrac{\partial q_{r}}{\partial y} +q'''
    \end{split}
\end{equation}
\end{document}

答案1

不清楚为什么要推动左边距的公式:要么没有,要么全部。后者是通过指定fleqn文档类选项获得的。

无论如何,我提出了几种您可以采用的方法(使用较窄的文本宽度)。

请注意输入的简化和几个\,标记的省略(以及错误的\;)。在两种情况下,我甚至添加了\!:当指数中\right)紧接着和时。\left(

偏导数工具使得输入更加易读。

\documentclass[12pt,a4paper]{article}
\usepackage{mathtools}
\usepackage{amssymb}
\usepackage{amsthm}

\usepackage{showframe}

\newcommand{\pder}[2]{\frac{\partial #1}{\partial #2}}

\begin{document}

Just the last term on the next line
\begin{equation}
\begin{aligned}
  \pder{T}{t}+\left(u\,\pder{T}{x} + v\,\pder{T}{y}\right)
  =
  \left(\frac{k_{2}}{\rho c_{p}}\right)\pder{^2 T}{y^2}
  +
  \left(\frac{\mu+\kappa}{\rho c_{p}}\right)\!\left(\pder{u}{y}\right)^{\!2}
  +
  \left(\frac{\sigma B_{0}^2}{\rho c_{p}}\right) u^2
  \\[1ex]
  {}-
  \dfrac{1}{\rho\,c_{p}}\,\pder{q_{r}}{y}+q'''
\end{aligned}
\end{equation}

Just the last term in the next line, but pushed a bit to the left
\begin{equation}
\begin{aligned}
  \pder{T}{t}+\left(u\,\pder{T}{x} + v\,\pder{T}{y}\right)
  =
  \left(\frac{k_{2}}{\rho c_{p}}\right)\pder{^2 T}{y^2}
  +
  \left(\frac{\mu+\kappa}{\rho c_{p}}\right)\!\left(\pder{u}{y}\right)^{\!2}
  +
  \left(\frac{\sigma B_{0}^2}{\rho c_{p}}\right) u^2
  \\[1ex]
  {}-
  \dfrac{1}{\rho\,c_{p}}\,\pder{q_{r}}{y}+q''' \qquad
\end{aligned}
\end{equation}

Two terms in the next line
\begin{equation}
\begin{aligned}
  \pder{T}{t}+\left(u\,\pder{T}{x} + v\,\pder{T}{y}\right)
  =
  \left(\frac{k_{2}}{\rho c_{p}}\right)\pder{^2 T}{y^2}
  +
  \left(\frac{\mu+\kappa}{\rho c_{p}}\right)\!\left(\pder{u}{y}\right)^{\!2}
  \\[1ex]
  {}+
  \left(\frac{\sigma B_{0}^2}{\rho c_{p}}\right) u^2
  -
  \dfrac{1}{\rho\,c_{p}}\,\pder{q_{r}}{y}+q'''
\end{aligned}
\end{equation}

A more conventional set up
\begin{multline}
  \pder{T}{t}+\left(u\,\pder{T}{x} + v\,\pder{T}{y}\right)
  =
  \left(\frac{k_{2}}{\rho c_{p}}\right)\pder{^2 T}{y^2}
  +
  \left(\frac{\mu+\kappa}{\rho c_{p}}\right)\!\left(\pder{u}{y}\right)^{\!2}
  \\[1ex]
  +
  \left(\frac{\sigma B_{0}^2}{\rho c_{p}}\right) u^2
  -
  \dfrac{1}{\rho\,c_{p}}\,\pder{q_{r}}{y}+q'''
\end{multline}

A more conventional set up with just one term on the next line
\begin{multline}
  \pder{T}{t}+\left(u\,\pder{T}{x} + v\,\pder{T}{y}\right)
  =
  \left(\frac{k_{2}}{\rho c_{p}}\right)\pder{^2 T}{y^2}
  +
  \left(\frac{\mu+\kappa}{\rho c_{p}}\right)\!\left(\pder{u}{y}\right)^{\!2}
  +
  \left(\frac{\sigma B_{0}^2}{\rho c_{p}}\right) u^2
  \\[1ex]
  -
  \dfrac{1}{\rho\,c_{p}}\,\pder{q_{r}}{y}+q'''
\end{multline}

\end{document}

在此处输入图片描述

答案2

由于使用的边距较窄,我认为将方程式分成两行没有好处。要将此方程式(以及所有其他方程式)左对齐,我建议您将其指定fleqn为文档类选项。哦,我还会去掉不必要的高括号。

在此处输入图片描述

\documentclass[12pt,a4paper,fleqn]{article}
%%\usepackage[utf8]{inputenc} % that's the default nowadays
\usepackage[T1]{fontenc}
\usepackage[margin=1cm]{geometry}
\usepackage{amssymb,mathtools,amsthm}

\begin{document}

\begin{equation}
    \frac{\partial T}{\partial t}
     +\left(u\,\frac{\partial T}{\partial x} 
          + v\,\frac{\partial T}{\partial y}\right)
    = \frac{k_{2}}{\rho\,c_{p}}\, \frac{\partial^2 T}{\partial y^2}
      +\frac{\mu+\kappa}{\rho\,c_{p}} 
         \left(\frac{\partial u}{\partial y}\right)^{\!\!2} 
      +\frac{\sigma B_{0}^2}{\rho\,c_{p}}\,u^2 
      -\frac{1}{\rho\,c_{p}}\,\frac{\partial q_{r}}{\partial y} 
      +q'''
\end{equation}

\end{document}

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