参考文献以BibTex格式原样拷贝到latex-bib中，编译后生成的pdf文件中特殊字符不能原样显示，并且对应字符显示为‘?’号，解决办法是特殊字符在latex文件中有对应的表示方法，如下。

🍎Special Symbols and escapes LaTeX provides means to describe special characters like accents or umlauts using a special notation, which can be used just the same inside of BibTeX Entries.

🍏参考链接 http://www.bibtex.org/SpecialSymbols/