Raman Spectroscopy Investigations of Tagish Lake Nanodiamonds
Bibliographic record
Abstract
Introduction: Tagish Lake, a carbonaceous chondrite C2, fell on 18th January 2000 in Canada. According to [1], the meteorite contains about 3650–4330 (ppm) of nanodiamonds, while inferred from measurements of xenon [2] the abundance is 18002500 ppm. This is the highest nanodiamond abundance reported from chondrites. Raman spectroscopic signatures of separated nanodiamonds have been studied in the work presented here. Samples and Experiments: Nanodiamonds were separated following established procedures [3] Raman spectra have been recorded using the confocal Raman micro-spectrometer T-64000 (Jobin-Yvon) with Argon line λ=514.5 nm. Results: The spectra show a diamond peak at 1329 cm (FWHM of about 50 cm) and a broad peak around 1600 cm (Fig.1) [4]. Previous investigations of Allende meteorite presolar nanodiamonds showed peaks at 1326 cm and 1590 cm [5] what is in agreement of laboratory manufactured nanodiamonds Raman investigations [6]. Shifts of diamond peak positions (monocrystalline cubic diamond has Raman peak at 1332 cm) occur because of the nanometer crystal sizes [6] or because of different polytypes [7] of diamond occuring in the sample. References: [1] Grady M. M. et al. (2002) Meteoritics & Planetary Science 37:713-735. [2] Jakubowski T. et al. (2011) Goldschmidt 2011, Abstract #2944. [3] Amari S. et al. (1994) Geochimica et Cosmochimica Acta 58:459-470. [4] Jakubowski T. (2011) PhD thesis, Technical University of Lodz. [5] Gucsik A. et al. (2008) Proceedings of the IAU Symposium 251 “Organic Matter in Space”:335-339. [6] Osswald S. et al. (2009) Physical Review B 80:075419. [7] Phelps A.W. (1999) Lunar and Planetary Science, #1749.
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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".