NMR Study on Microscopic Pore Characteristics of Coals of Different Coal Ranks
Bibliographic record
Abstract
The microscopic pore structure of coal directly affects the adsorption and permeability of coal, while the coals of different coal ranks have significantly different microscopic pore structures. In this paper, the microscopic pore structure difference of coals of different ranks was studied by combining low temperature liquid nitrogen and nuclear magnetic resonance technology. The results showed that the desorption curve of high rank coal (ZM) was significantly inflected at (0.5 P/P0) and that of medium/low rank coal (XJ, HB, SX) was not inflected at (0.5 P/P0). High rank coal contains more "inkbottle"-shaped pores and slit pores, with complex pore system and poor connectivity between pores; while low\intermediate rank coal contains more open pores, with simple pore system and good connectivity between pores. NMR test showed that the micro pores (<10nm) of low/medium rank coal accounted for about 20% of the total pores, which was significantly lower than that of high rank coal (about 70%); however, the macro pores of low/medium rank coal accounted for about 10% of the total pores, which was higher than that of high rank coal. The T2 spectrum of low-rank coal (XJ) presents a continuous threepeak distribution, and the total area of T2 spectrum is 13400 (dimensionless). The T2 spectrum of medium rank coal (HB, SX) shows bimodal and trimodal distribution (where bimodal distribution is dominant), with a total area of T2 spectrum being 3040. High coal rank (ZM) presents a bimodal distribution, with a total area of T2 spectrum of 19080. This study provides a theoretical basis for the exploration and development of coal bed gas and the safety production of coal mine.
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 | 0.000 | 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 | 0.000 | 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) | 0.000 | 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".