Determination of natural isotopic variation in nickel using inductively coupled plasma mass spectrometry
Bibliographic record
Abstract
In this study, we measured natural isotopic variation of terrestrial nickel using multiple-collector inductively coupled plasma mass spectrometry. External precisions in 58Ni/62Ni, 60Ni/62Ni, 61Ni/62Ni, and 64Ni/62Ni ratios of 0.02%, 0.01%, 0.04%, and 0.09% (2 × standard deviation), respectively, were routinely obtainable for a Ni isotopic reference standard by correcting the mass discrimination effect with a 65Cu/63Cu ratio of 0.4456. Only a small isotopic variation of ±0.15‰ amu−1 was observed among seven commercially available reagent-grade nickel metals, while variation of ±0.20‰ amu−1 was observed for two nickel sulfide samples from Canada. The isotopic compositions of the two types of samples overlap. The overall variation of ±0.25‰ amu−1 corresponds to an uncertainty of 0.000 37 for the atomic weight of nickel; this uncertainty is twice the currently recommended value (56.6934 ± 0.0002) for the standard atomic weight of terrestrial nickel as proposed by IUPAC.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".