重新定义 \em，使其在文档的引用部分不执行任何操作

Question

我当前的格式如下：

我希望它是这样的：

我发现问题> bibtex References.bib产生了main.bbl 以下结果。

\begin{thebibliography}{1}

\bibitem{shimomura}
下村健治.
\newblock {\em うんこうんこうんち}.
\newblock コロナ社, 1998.

\end{thebibliography}

我需要 {em} 部分不要变成粗体。以下是评论中的建议，我认真遵循了本文生成可编译文件。这是main.tex

\documentclass[11pt,a4j]{jreport}
\usepackage[dvipdfm]{graphicx}

\begin{document}
\LaTeX{} \cite{latex2e} is a set of macros built atop \TeX{} \cite{texbook}.
\clearpage
\baselineskip=7.0mm
\bibliographystyle{plain} % We choose the "plain" reference style
\bibliography{refs} % Entries are in the refs.bib file

\end{document}

refs.bib这是该文章中包含的示例。

@book{texbook,
  author = {Donald E. Knuth},
  year = {1986},
  title = {The {\TeX} Book},
  publisher = {Addison-Wesley Professional}
}

@book{latex:companion,
  author = {Frank Mittelbach and Michel Gossens
            and Johannes Braams and David Carlisle
            and Chris Rowley},
  year = {2004},
  title = {The {\LaTeX} Companionお願いします。},
  publisher = {Addison-Wesley Professional},
  edition = {2}
}

@book{latex2e,
  author = {Leslie Lamport},
  year = {1994},
  title = {{\LaTeX}: a Document Preparation Systemお願いします。},
  publisher = {Addison Wesley},
  address = {Massachusetts},
  edition = {2}
}

@article{knuth:1984,
  title={Literate Programming},
  author={Donald E. Knuth},
  journal={The Computer Journal},
  volume={27},
  number={2},
  pages={97--111},
  year={1984},
  publisher={Oxford University Press}
}

@inproceedings{lesk:1977,
  title={Computer Typesetting of Technical Journals on {UNIX}},
  author={Michael Lesk and Brian Kernighan},
  booktitle={Proceedings of American Federation of
             Information Processing Societies: 1977
             National Computer Conference},
  pages={879--888},
  year={1977},
  address={Dallas, Texas}
}

编译为

> platex main 
> bibtex main
> platex main
> platex main
> dvipdfm main

我从原始主 tex 文件中省略了许多行，因此参考文献的标题发生了变化，但问题仍然存在，标题的日文部分以粗体显示。