update README.md.

Signed-off-by: 山东大学-刘明宏 <liuminghong@mail.sdu.edu.cn>

README.md

@@ -26,4 +26,4 @@ The authors recommend installing the latest version of the software.
 
 #### 如何引用 How to Cite
 
- The paper was submitted to Computers & Geosciences under the title "efficient geophysical modeling techniques for complex real geological structures".
+ The paper was submitted to  _Computers & Geosciences_  under the title "efficient geophysical modeling techniques for complex real geological structures".