Notice bibliographique
Résumé
Electron paramagnetic resonance techniques have been used to investigate the nature and possible effects of adsorption of gaseous species on several adsorbents, in particular several synthetic zeolites, at temperatures from 77°K upwards. Analysis of the spectra obtained has been aided through computer simulation of the various spectra and comparison of these to the actual observed spectra. The molecule chlorine dioxide ( C10₂ ) has been studied in various low temperature matrices but little has been published for C10₂ in the adsorbed state. An attempt was made to find an adsorbent such that an inert matrix might be approximated, to give a base from which to make comparisons. To this end, adsorbents including silica gel, synthetic zeolites 13X, 10X, 4A, 5A, Na-mordenite and H-mordenite were investigated. The results vary between those from silica gel, where spectra yielding EPR parameters similar to other matrices were obtained, to those from 13X where it was evident that two distinct adsorption sites of the C10₂ were present. In the 13X as in the other synthetic zeolites, EPR parameters markedly different from other studies were found and were attributed to the intense electrostatic fields present in these zeolites. Results obtained at room temperature for these adsorbents ranged from C10₂ molecules freely rotating in the cages of the zeolites to other molecules having hindered rotations. Nitrogen dioxide ( NO₂ ) was also investigated with a view to finding similar interactions. Although changes as marked as for C10₂ compared to other studies were not observed, the synthetic zeolite H-mordenite yielded spectra closely approximating those obtained in solid N₂O₄ matrices. It is proposed the NO₂ molecules are caged in the numerous side pockets emanating from the main channels in this zeolite and are effectively isolated from other NO₂ molecules. The resulting spectra are strikingly more resolved than those obtained using other adsorbents and enabled accurate computer simulations to be made. The adsorption of nitric oxide ( NO ) produced an effect not found with the other molecules. A new species was formed from a reaction of the NO with H-mordenite and could not be removed at room temperature, indicating a strong bond to the surface. The new species does not contain nitrogen as identical spectra were obtained from adsorption of ¹⁴NO and ¹⁵NO. Attempts to observe spectra which could be assigned to the difluoroamino radical from adsorption of tetrafluorohydrazine were unsuccessful. The spectra observed were assigned to a species having no hyperfine structure and an anisotropic g tensor.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,004 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».