看看下面的代码：
% Preview source code
%% LyX 2.3.0 created this file. For more info, see http://www.lyx.org/.
%% Do not edit unless you really know what you are doing.
\documentclass[a4paper,english,hebrew]{article}
\usepackage{fontspec}
\usepackage{fancyhdr}
\pagestyle{fancy}
\setcounter{secnumdepth}{1}
\setcounter{tocdepth}{5}
\setlength{\parindent}{0bp}
\usepackage{color}
\usepackage[unicode=true,pdfusetitle,
bookmarks=true,bookmarksnumbered=false,bookmarksopen=false,
breaklinks=false,pdfborder={0 0 0},pdfborderstyle={},backref=false,colorlinks=true]
{hyperref}
\makeatletter
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% LyX specific LaTeX commands.
\pdfpageheight\paperheight
\pdfpagewidth\paperwidth
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands.
\usepackage{theorem}
\theorembodyfont{\upshape}
% The following chunk fixes export with XeTeX.
% It is needed because polyglossia is used by default
% and \make@lr is only defined by babel.
\@ifundefined{make@lr}
{\def\make@lr#1{\begingroup
\toks@=\expandafter{#1}%
\edef\x{\endgroup
\def\noexpand#1{\noexpand\@number{\the\toks@}}}%
\x}}{\relax}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.
\usepackage{xcolor}
\usepackage[explicit]{titlesec}
\usepackage{titletoc}
\usepackage[many]{tcolorbox}
\usepackage[framemethod=TikZ,framemethod=pstricks]{mdframed}
\tcbset{enhanced,colback=red!5!white,
boxrule=0pt,
colframe=blue!75!black,fonttitle=\bfseries}
\titleformat{\part}
{\normalfont\bfseries\Huge\selectfont}
{}{0pt}
{\begin{tcolorbox}[drop large lifted shadow=black,halign=center]
\center{Part\hskip0.7em\thepart\newline#1}\end{tcolorbox}}[]
\usepackage{polyglossia}
\setdefaultlanguage{hebrew}
\setotherlanguage{english}
\begin{document}
\begin{english}[variant=american]%
\part{Simple}
\end{english}%
\tableofcontents{}
\end{document}
结果如下：
Part I不在中心是什么样的Simple？
谢谢你！
答案1
仅使用
\begin{tcolorbox}[drop large lifted shadow=black,halign=center]
{Part~\thepart\\#1}
\end{tcolorbox}
