Application of the diffraction theory for photothermal deflection to the measurement of the temperature coefficient of the refractive index of a binary gas mixture
Bibliographic record
Abstract
The application of recently developed diffraction theory for continuous wave photothermal deflection (PD) spectroscopy in the measurement of the temperature coefficient of the refractive index, dn∕dT, of a gas as a deflecting medium was presented. Both amplitude and phase signals were elucidated for a better interpretation and a simultaneous measurement of the thermal diffusivity αg and dn∕dT. The probe-beam size effect (PBSE) on the PD phase signal was also quantitatively analyzed to clearly show its physical meaning. A distance-scan method to measure the distance x between the probe beam and sample, which was difficult to determine in the PD, but a necessary parameter for measuring dn∕dT, was proposed. The consistent values of x measured respectively from the amplitude and the phase could not be obtained without considering the PBSE. αg and dn∕dT of pure gases (O2, N2, and CO2) and binary gas mixtures (O2-CO2 and N2-CO2) were precisely measured with the measured x. The measured αg and dn∕dT of pure gases were in very good agreement with the literature values, and furthermore the measured dn∕dT values of the pure gases had one more significant figure than the literature ones, demonstrating the high precision of this method. It was found the behavior of αg and dn∕dT of a binary gas mixture versus concentration could be described by a thermodynamic theory and the Lorentz-Lorenz formula, respectively.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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 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".