| Share | Phrase |
|---|
| 61.07% | background [physical/chemical] art |
| 10.24% | background [physical/chemical] information |
| 9.57% | background [physical/chemical] loop |
| 5.73% | background [physical/chemical] job |
| 3.27% | background [physical/chemical] processing |
| 3.00% | background [physical/chemical] routine |
| 1.99% | background [physical/chemical] noise |
| 1.12% | background [physical/chemical] section |
| 0.86% | background [physical/chemical] discussion |
| 0.68% | background [physical/chemical] interference |
| 0.59% | background [physical/chemical] level |
| 0.53% | background [physical/chemical] technique |
| 0.49% | background [physical/chemical] radiation |
| 0.45% | background [physical/chemical] operation |
| 0.33% | background [physical/chemical] process |