1H-detected measurement of spin relaxation constants in ultrawide solid-state NMR line shapes via progressive saturation of the proton reservoir
Bibliographic record
Abstract
Nuclear magnetic resonance relaxation time constants provide valuable insights into the dynamic processes and structure of a system. However, determination of these relaxation parameters is often challenging for low-γ nuclides, which exhibit low sensitivity and are typically subject to large anisotropic interactions. Here, we introduce two new pulse sequences, PROSPR-T1 and PROSPR-T2, for measuring longitudinal and transverse relaxation time constants in solids. These sequences are modifications of the PROgressive Saturation of the Proton Reservoir (PROSPR) experiment, developed to facilitate the detection of insensitive nuclides. Following an initial analysis of the adiabatic requirements of the PROSPR experiment, the performance of PROSPR to measure T1/T2' is thoroughly evaluated on a range of spins, including 119Sn (I = 1/2), 35Cl (I = 3/2), and 14N (I = 1). Experimental results demonstrate that optimized versions of PROSPR can be up to an order of magnitude more sensitive than their original implementation. These new methods offer accurate relaxation time constants, even for spectra spanning over 1 MHz, without demanding frequency stepping throughout the powder pattern.
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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) | 0.000 | 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 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 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".