An inductively coupled plasma study and an ion cyclotron resonance matrix‐assisted laser/desorption study at high mass resolution of two ancient Maya greenstone artifacts from Pacbitun, Belize, and two decorative jade specimens
Bibliographic record
Abstract
RATIONALE: Two Early Classic period (ca 250-600 CE) Maya carved, greenstone jade pendants, Specimens A and B, were recovered from the Pacbitun site in Belize in 1987. Mass scans of resolution ~600,000 were obtained for the jade pendants and two British Columbia jade ornaments. METHODS: Polyatomic ions from jade grit have been observed using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), specifically the Bruker Daltonics, SolariX XR, combined with matrix-assisted laser desorption/ionization (MALDI); the matrix material was α-cyano-4-hydroxycinnamicacid. RESULTS: Presented here is an interpretation of the mass spectrometric observations from multiplicities of silicate materials. Observation of novel polyatomic ion species of m/z 800-1400 indicate the ejection of charged ensembles composed of 60-180 atoms from jade grit. The charged ensembles represent minute regions of jade grit that have retained many of the spatial relationships of atoms within the jade; the required ejection energy is provided by laser photons accumulated in the matrix. Acid solutions of grit from Specimens A and ornament KMM were analyzed by inductively-coupled plasma mass spectrometry. The novelty of this application of mass spectrometry to jade was reported in the Journal of Archaeological Science: Reports. CONCLUSIONS: Isotopic fine structure analysis can yield elemental compositions for ions composed of base isotopes together with stable isotope intensities arising from ions with one and two additional neutrons. The analysis is challenging as jade is a multiplicity of similar solid solutions; thus, a multiple isotopic fine structure approach has been explored. Attempts to compose ensembles of atoms, of those elements found normally in coloured silicates, to match the observed ion mass/charge ratios were unsuccessful without the addition of multiple hydrogen atoms. The production of polyatomic ions of siliceous material may permit impinging fine glass coatings onto construction materials for protection against fire and weather.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 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 teacher head, 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".