Update README.md

README.md

@@ -18,7 +18,7 @@ The **video of Bgolearn** has been uploaded to platforms : [BiliBili](https://ww
     Cao, Bin and Su, Tianhao and Yu, Shuting and Li, Tianyuan and Zhang, Taolue and Dong, Ziqiang and Zhang, Tong-Yi, Active Learning Accelerates the Discovery of High Strength and High Ductility Lead-Free Solder Alloys. Available at SSRN: https://ssrn.com/abstract=4686075 or http://dx.doi.org/10.2139/ssrn.4686075. [GitHub : github.com/Bin-Cao/Bgolearn.]
 
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-    Ma, J.&, Cao, B.&, Dong, S. et al. MLMD: a programming-free AI platform to predict and design materials. npj Comput Mater 10, 59 (2024). https://doi.org/10.1038/s41524-024-01243-4
+    Ma, J.∔, Cao, B.∔, Dong, S. et al. MLMD: a programming-free AI platform to predict and design materials. npj Comput Mater 10, 59 (2024). https://doi.org/10.1038/s41524-024-01243-4
 
 
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