我对 LaTeX 中的模板还不太熟悉els-cas-dc。我想向 Elsevier 提交一篇论文，因此我下载了“els-cas-templates”包。具体来说，我的论文是两栏论文，所以我尝试使用 els-cas-dc 类。当我在 MacBook 上使用 TeXmaker 进行编译时，我收到以下错误消息：
“/usr/local/texlive/2022/texmf-dist/tex/latex/els-cas-templates/cas- dc.cls 错误第 61 行！LaTeX 错误：未找到文件“expl3.sty”。键入 X 退出或继续，或输入新名称。（默认扩展名：sty）输入文件名：！紧急停止。@ifundefined”
以下是我编写的代码：
\documentclass[a4paper,fleqn]{cas-dc}
\usepackage{booktabs,siunitx}
\usepackage{natbib}
\usepackage{geometry}
\sisetup{detect-all}
%\usepackage{cite}
\usepackage{amssymb,amsthm}
\emergencystretch=27pt %Allow 27pt of additional white space per line in order to avoid underfull/overfull lines
\hyphenpenalty=10000 %Prevent hyphenation if word is too long for line
\ExplSyntaxOn
\keys_set:nn { stm / mktitle } { nologo }
\ExplSyntaxOff
\begin{document}
\shorttitle{Adoption of Cocoa Agroforestry Technology and Productivity}
\shortauthors{Felix Larry Essilfie}
%\begin{frontmatter}
\title [mode = title]{Adoption of Cocoa Agroforestry Technology and Productivity: An Application of the Regression Adjustment Method with Weighting }
\author[1,2]{Felix Larry Essilfie}%[orcid=0000-0002-9398-9414]
%\author[1]{Nadeem Javaid*}
%\author[3]{Noor Islam}
%\author[1]{Khurram Saleem Alimgeer}
%\author[1]{Ammar Ali}
%\author[4]{Muhammad Riaz}
%\author[2]{Muhammad Usman}
\cortext[cor1]{Corresponding author}
\cormark[1]
\ead{[email protected]}
\ead[URL]{www.ideresearch.org}
\address[1]{Institute of Development and Economic Research, No. 24 Bugatti St., Asheyie-Down, Adenta, Accra, Ghana}
\address[2]{Department of Agricultural Economics and Agribusiness, University of Ghana, Legon}
%\address[3]{CECOS University of IT \& Emerging Sciences, Peshawar 25124, Pakistan}
%\address[4]{Wah Engineering College, University of Wah, Wah Cantt 47070, Pakistan}
%and Khurram Saleem Alimgeer$^1$
\begin{abstract}[S U M M A R Y]
The study uses a sample of 1,175 cocoa farmers to assess the effects of cocoa agroforestry technology on the productivity of maize farmers. An approach that combines the regression adjustment method with weighting to estimate the treatment parameters was employed for the study. The approach is a generalization of the doubly robust estimation methods for different treatment parameters, which are defined in a multivalued treatment effect estimation framework.\par
\end{abstract}
\begin{keywords}
Short term load forecasting;competition-2012.
\end{keywords}
\maketitle
\section{introduction}
\end{document}