如何获取特殊大写标题

Question

如果之前有人问过这个问题，我很抱歉，但是我进行了一些搜索，但找不到答案，因为如果不提供图片就很难表述这个问题。

我想知道作者是如何让文本在 1. 简介和 2. 通用包络代数中看起来像那样的？

Answer 1

居中大写和小型大写标题，amsart对我来说看起来像是类。

\documentclass{amsart}
\begin{document}
 \section{Introduction}
\end{document}

Answer 2

使用sectsty，另一种方式。

\documentclass{article}
\usepackage{sectsty}
\sectionfont{\centering\normalfont\scshape}
%\allsectionsfont{\centering\normalfont\scshape}  % for all sectional levels
\usepackage{lipsum}
\begin{document}
    \section{Introducton}
    \lipsum[1]
    \section{Another Section}
    \lipsum[2]
\end{document}

Answer 3

使用以下所有工具的解决方案titlesec：

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[textwidth=140mm, textheight=213mm, marginratio={4:6,5:7}]{geometry}
\usepackage{amsmath, amsfonts, amssymb}
\DeclareMathOperator\GL{\mathfrak{gl}}
\DeclareMathOperator\chr{char}
\usepackage[noindentafter]{titlesec}

\titleformat{\section}[block]{\filcenter\scshape}{\thesection.}{0.5em}{}
\titlespacing*{\section}{0pt}{2\baselineskip}{1\baselineskip}

\begin{document}

\section{Introduction}

Let $ L $ be a finite dimensional Lie algebra over the field $ F $. By a finite-dimensional representation, we mean a Lie algebra homomorphism $ φ \colon L → \GL(V)$ for some vector space $ V $ with $ \dim V < ∞ $. When $ φ $ is injective, $ φ $ is said to be a \emph{faithful} representation. If $ L $ has a faithful representation, then we can view elements of $ L$ as matrices with entries in $ F $. It is natural to ask whether every finite dimensional Lie algebra can be concretely realized in this way. Ado [1] gave an affirmative answer when $ \chr(F) = 0$. The result was extended by Iwasawa [2] to cover the case $ \chr(F) = p $ for prime $ p $. We follow Fulton and Harris [3] to give the proof for the case $ \chr(F) = 0 $.

\section{Universal Enveloping Algebras}

\end{document} 

Answer 4

\documentclass{article}
\usepackage[explicit]{titlesec}
\titleformat{\section}{\normalfont}{\thesection}{1em}{\centering\textsc{#1}}
\usepackage{lipsum}
\begin{document}
    \section{Introducton}
    \lipsum[1]
    \section{Another Section}
    \lipsum[2]
\end{document}