Composition and origin of low-molecular-weight hydrocarbons in the gas-hydrate-bearing sediments from the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well
Bibliographic record
Abstract
Forty-eight samples of gas-hydrate-bearing sediments were collected from the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well for measurement of solvent-extractable organic compounds and 'extraction' gases. The n-alkanes, triterpenoids, and steroid hydrocarbons were identified from the solvent-soluble organic matter. The n-alkane distribution patterns confirm that the organic matter is mainly derived from higher land plants. An observed feature of both mature and low-maturity compounds in the gas hydrate zone was the odd-even predominance pattern in the distribution of n-alkanes, steroids, and triterpenoids. The mature compounds probably migrated from much deeper, thermally matured sediments, whereas low-maturity compounds were generated from in situ organic matter, particularly lignite. The extraction gases from the gas hydrate zone contain methane, ethane, propane, and n-butane. Higher concentrations of hydrocarbon gases were observed in the gas hydrate intervals. The carbon isotopic compositions of methane and the molecular ratios are those of a typical thermogenic gas.
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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 | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 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".