<sup>17</sup> O NMR Spectroscopy of α‐TeO <sub>2</sub> and Na <sub>2</sub> TeO <sub>3</sub>
Bibliographic record
Abstract
The synthesis of 17 O‐enriched α‐tellurite (α‐TeO 2 ) is described. TeO 2 is obtained stochiometrically by the reaction of tellurium isopropoxide with 17 O‐enriched H 2 O. The reaction is mild and simple and opens the field of tellurite‐based ceramics to 17 O nuclear magnetic resonance spectroscopy. We also report the first 17 O nuclear magnetic resonance spectra of α‐TeO 2 and Na 2 TeO 3 . Their isotropic chemical shifts, δ iso , are 180 ppm and 158 ppm, respectively, and their quadrupolar coupling parameters are C Q =7.48 MHz and η=0.43 for α‐TeO 2 , and C Q =6.63 MHz and η=0.33. By using extended Hückel tight binding calculations, we interpret the chemical shifts of tetravalent inorganic oxide network formers (SiO 2 , GeO 2 , and TeO 2 ) in terms of the local paramagnetic shielding effect. We also show that this is the predominant effect in determining the chemical shifts of non‐bridging oxide sites in this type of network.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".