Fig. 1 (IMAGE) Science China Press Caption Schematic diagram of device structure and secondary grain growth with (NH4)2C2O4* H2O treatment. Credit ©Science China Press Usage Restrictions Use with credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.