我想在subnumcases
环境中编写与同一方程关联的新行,因为整个方程太大,无法放入一行中。为此,我尝试使用命令\\
创建新行,编写以下代码(参见与第二个标签关联的方程\label{eq:T_trh_rot_equation_1D_implementation}
):
\documentclass{article}
\usepackage{amsmath}
\usepackage{cases}
\begin{document}
\begin{subnumcases}{}
\frac{d c_{s,e,v}}{d x}=\frac{\dot{\omega}_{s,e,v}}{\rho u},\,\,\,\,\,\,\,\,\,\forall s,\,e\,\text{and }v\text{ ,}
\label{eq:mass_equation_ve_1D_final_implementation}
\\
\frac{d T_{\text{tr}_\text{h}}}{dx}+\frac{\left(\sum_{s\in\{\text{h}\}} c_s\right)u}{\sum_{s\in\{\text{h}\}}c_sC_{p,s,\text{tr-rot}}}\cdot\frac{du}{dx}=\\
=-\frac{\dot{\Omega}_{\text{rad}}+\left(\sum_s\dot{\Omega}_{s,\text{e}}^{\text{int}}\right)+\left[\sum_{s\in\{\text{h}\}}\dot{\omega}_s\left(h_s+\frac{1}{2}u^2\right)\right]+\left[\sum_{s\in\{\text{h}\},e,v}\left(\dot{\omega}_{s,e,v}-\frac{c_{s,e,v}}{c_s}\dot{\omega}_s\right)\frac{\epsilon_{s,\text{el-vib},e,v}}{m_s}\right]}{\rho u\left(\sum_{s\in\{\text{h}\}}c_sC_{p,s,\text{tr-rot}}\right)}\text{ ,}
\label{eq:T_trh_rot_equation_1D_implementation}
\\
\frac{d T_{\text{tr}_\text{e}}}{d x}+\frac{u}{C_{p,\text{e}}}\frac{du}{dx}=\frac{\left(\sum_s\dot{\Omega}_{s,\text{e}}^{\text{int}}\right)-\dot{\omega}_\text{e}\left(h_\text{e}+\frac{1}{2}u^2\right)}{\rho u c_\text{e}C_{p,\text{e}}}\text{ .}
\label{eq:T_tre_equation_1D_implementation}
\end{subnumcases}
\end{document}
其结果是:
由于环境使用此命令来分隔方程式,因此为两条线分配了两个参考编号 (1b) 和 (1c) subnumcases
。我只想要一个标签(即当前 (1c),由于隐藏了前一个 (1b),因此应将其更改为“(1b)”),因为它对应于单个方程式。是否有任何命令可以为同一方程式创建一个新行并为其添加单个标签?
答案1
我找到了一种方法,在环境中将方程分成两行subnumcases
,并给它一个标签。它需要使用命令\parbox
,该命令允许\\
插入命令而不创建新方程。框的长度定义为与第二行相关联的长度(因为它是两行中最大的),使用命令\widthof
(包的calc
命令)来计算它。新代码是
\documentclass{article}
\usepackage{amsmath}
\usepackage{cases}
\usepackage{calc}
\begin{document}
\begin{subnumcases}{}
\frac{d c_{s,e,v}}{d x}=\frac{\dot{\omega}_{s,e,v}}{\rho u},\,\,\,\,\,\,\,\,\,\forall s,\,e\,\text{and }v\text{ ,}
\label{eq:mass_equation_ve_1D_final_implementation}
\\
\parbox{
\widthof{$
\displaystyle
=-\frac{\dot{\Omega}_{\text{rad}}+\left(\sum_s\dot{\Omega}_{s,\text{e}}^{\text{int}}\right)+\left[\sum_{s\in\{\text{h}\}}\dot{\omega}_s\left(h_s+\frac{1}{2}u^2\right)\right]+\left[\sum_{s\in\{\text{h}\},e,v}\left(\dot{\omega}_{s,e,v}-\frac{c_{s,e,v}}{c_s}\dot{\omega}_s\right)\frac{\epsilon_{s,\text{el-vib},e,v}}{m_s}\right]}{\rho u\left(\sum_{s\in\{\text{h}\}}c_sC_{p,s,\text{tr-rot}}\right)}\text{ ,}
$}}
{$
\displaystyle
\frac{d T_{\text{tr}_\text{h}}}{dx}+\frac{\left(\sum_{s\in\{\text{h}\}} c_s\right)u}{\sum_{s\in\{\text{h}\}}c_sC_{p,s,\text{tr-rot}}}\cdot\frac{du}{dx}=\\
=-\frac{\dot{\Omega}_{\text{rad}}+\left(\sum_s\dot{\Omega}_{s,\text{e}}^{\text{int}}\right)+\left[\sum_{s\in\{\text{h}\}}\dot{\omega}_s\left(h_s+\frac{1}{2}u^2\right)\right]+\left[\sum_{s\in\{\text{h}\},e,v}\left(\dot{\omega}_{s,e,v}-\frac{c_{s,e,v}}{c_s}\dot{\omega}_s\right)\frac{\epsilon_{s,\text{el-vib},e,v}}{m_s}\right]}{\rho u\left(\sum_{s\in\{\text{h}\}}c_sC_{p,s,\text{tr-rot}}\right)}\text{ ,}
$}
\label{eq:T_trh_rot_equation_1D_implementation}
\\
\frac{d T_{\text{tr}_\text{e}}}{d x}+\frac{u}{C_{p,\text{e}}}\frac{du}{dx}=\frac{\left(\sum_s\dot{\Omega}_{s,\text{e}}^{\text{int}}\right)-\dot{\omega}_\text{e}\left(h_\text{e}+\frac{1}{2}u^2\right)}{\rho u c_\text{e}C_{p,\text{e}}}\text{ .}
\label{eq:T_tre_equation_1D_implementation}
\end{subnumcases}
\end{document}