Molecular dynamics in a mixture of 8OCB-d17 and 6OCB showing nematic and reentrant nematic phases: A deuterium nuclear magnetic resonance study
Bibliographic record
Abstract
A deuteron NMR study of the molecular dynamics of 4-n-octyloxy-4′-cyanobiphenyl (8OCB) in the mixture of 72 wt % of 8OCB and 28 wt % of 4-n-hexyloxy-4′-cyanobiphenyl is presented. The mixture has the same composition as the one used before (Shen and Dong, 1998) except in the deuteration of the component molecule. The deuteron Zeeman and quadrupolar spin-lattice times and quadrupolar splittings were measured in the nematic, smectic A, and reentrant nematic phases at 15.1 and 46 MHz. The additive potential method was employed to construct the potential of mean torque based on the observed splittings. The spectral density data from the relaxation times were interpreted in terms of the internal conformational motions of the chain decoupled from the molecular small-step rotational diffusion and the order director fluctuations. The latter motion was found to be essential to the fit of experimental results in the nematic phase. The fitting parameters obtained using a global target fitting method are acceptable when compared with those obtained from other deuteron and proton NMR studies of the same mesophases.
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 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 | 0.000 | 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".