Irradiator to study damage induced to large nonvolatile molecules by low-energy electrons
Bibliographic record
Abstract
We report on the design and performance of an irradiator to study the fragmentation of large nonvolatile molecules induced by low-energy electron impact under ultrahigh vacuum. The apparatus consists essentially of a new type of electron gun which can bombard molecules spin-coated on the inside surface of a cylinder. With this configuration, it is possible to irradiate a relatively large area (26 cm2) of a solid molecular film and thus, produce a sufficient amount of degraded material for subsequent analysis, outside vacuum, of the compounds remaining on the inner surface of the cylinder. The electron energy is tunable from 3 to 130±0.5 eV and the current density adjustable up to 2.6±0.5×1012 electron s−1 cm−2, respectively. Choosing thymidine as a model system for deoxyribose nucleic acid damage, we show that nonvolatile fragments produced by 5–100 eV electron irradiation can be characterized by high-pressure liquid chromatography/ultraviolet detector and gas chromatography/mass spectroscopy.
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 | 0.001 | 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".