Effect of grain size and domain state on thermal demagnetization tails
Bibliographic record
Abstract
Thermal demagnetization of viscous remanence (VRM) and partial thermoremanence (pTRM) of 20‐ and 135‐µm natural magnetites reveals a broad spectrum f(TUB) of unblocking temperatures TUB, both > and < TB, the blocking temperature. In contrast, 0.04‐µm single‐domain (SD) grains demagnetize sharply at TUB ≈ TB. High‐ and low‐TUB tails of f(TUB) were wider for 135‐µm multidomain (MD) grains than for 20‐µm PSD grains. 10‐mT alternating‐field demagnetization rendered the VRM of the 20‐µm magnetite more SD‐like in subsequent thermal cleaning, selectively erasing both low‐ and high‐TUB tails of f(TUB). Primary and secondary remanences are then cleanly separated, and non‐linear Thellier paleointensity determination becomes linear. Our results agree well with (TB, TUB) data for 105‐year thermoviscous overprints in the Milton Monzonite over the range of log(time) common to the two studies. Because (TUB)av ≈ TB for PSD and MD as well as SD grains, the Pullaiah et al. paleothermometry method will work if (TUB)av values are used instead of (TUB)max values.
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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 | 0.001 |
| 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) | 0.002 | 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".