| Wavenumber (cm-1) | Assignment                                                                                                        |
| 400-600           | Bending vibrations of the Al-O-Al or Al-O-Si bonds [18,20] Si-O in the silicon-oxygen framework of the glass [10] |
| 691-720           | Bending vibration of B-O-B in BO3 triangles [36-38]                                                               |
| 830-883, 928-1191 | Stretching vibration of BO4 units in various structural groups [36-38]                                            |
| 1200-1500         | B-O stretching vibrations of trigonal BO3 units only [36-38]                                                      |

Caption: Assignment of absorption bands in the infrared spectra of the glass system xPbO-RNa2B4O7-(100- R - x)CAS with 0 x 50, and 50 R 75mol%.

You are provided with a table from a material science paper. Here are JSON templates for two types of numeric cells: "Other" and "Glass_Compound_Amount":
{"value": "xx", "type": "Other"}
{"value": "xx", "type": "Glass_Compound_Amount", "constituent": "xx", "unit": "xx", "material": "xx"}

Please describe all numeric cells in the above table following the JSON templates (proceeding by row in a left-right, top-down direction). For each cell, output one JSON description per line. For any unanswerable attributes in the templates, set their value to the placeholder "xx".

Cell Description:
{"value": "400", "type": "Other"}
{"value": "600", "type": "Other"}
{"value": "691", "type": "Other"}
{"value": "720", "type": "Other"}
{"value": "1200", "type": "Other"}
{"value": "1500", "type": "Other"}