When a metal element reacts with a non-metal element an ionic compound is formed. When a non-metal element reacts with a non-metal element a covalent bond is formed. Structures and properties ...

A universal approach to construct low-resistance oxide layer by multiple tunnelling paths is proposed for efficient and durable Si-based photocathode. This approach can speed up the pace of ...

Physics is the search for and application of rules that can help us understand and predict the world around us. Central to physics are ideas such as energy, mass, particles and waves. Physics attempts ...