Search results for "Bay"
showing 10 items of 1187 documents
Iodine speciation in marine aerosols along a 30,000 km round-trip cruise path from Shanghai, China to Prydz Bay, Antarctica
2008
[1] Total suspended particle (TSP) samples were collected onboard a round-trip cruise from Shanghai, China to Prydz Bay, Antarctica from November 2005 to March 2006. Water soluble iodine species were measured using ion chromatography coupled to Inductively Coupled Plasma-Mass Spectrometry (IC-ICP-MS). The results reveal that soluble organic iodine (SOI) is the most abundant fraction, accounting for approximately 70 % of total soluble iodine (TSI) on average. One unidentified organic iodine (UOI) signal was present in almost all of the samples and was responsible for up to 38.3% of TSI. The abundance of inorganic iodine species, iodate and iodide, was less than 30% of TSI. Iodide was signifi…
Polystyrene-supported proline as recyclable catalyst in the Baylis–Hillman reaction of arylaldehydes and methyl or ethyl vinyl ketone
2008
Abstract Polystyrene-supported proline has been used as co-organocatalyst (10 mol%) with imidazole (10 mol%) in the Baylis–Hillman reaction between methyl or ethyl vinyl ketone and arylaldehydes. Recycling studies showed that the proline resin can be used up to five cycles with high isolated yields. This study represents the first example of supported proline as heterogeneous catalyst in the above reaction and broaden the scope of this catalytic material.
First Evidence of Proline Acting as a Bifunctional Catalyst in the Baylis–Hillman Reaction Between Alkyl Vinyl Ketones and Aryl Aldehydes
2008
Proline in the presence of sodium hydrogen carbonate has been found to be an effective catalyst for the Baylis–Hillman reaction between methyl or ethyl vinyl ketone and aryl aldehydes. Screening of several amine catalysts showed that an ionizable carboxylic function directly linked to the secondary amine catalyst plays an important role in the synthesis of the desired product in good yield. The data obtained has allowed us to suggest, for the first time, that proline, sarcosine, pipecolinic acid and homoproline may act as bifunctional catalysts via a bicyclic enaminolactone species as intermediate. Quantum-mechanical calculations (PM3/COSMO and ab initio 3-21G/COSMO) support this mechanism …
ChemInform Abstract: First Evidence of Proline Acting as a Bifunctional Catalyst in the Baylis-Hillman Reaction Between Alkyl Vinyl Ketones and Aryl …
2008
Proline in the presence of sodium hydrogen carbonate has been found to be an effective catalyst for the Baylis–Hillman reaction between methyl or ethyl vinyl ketone and aryl aldehydes. Screening of several amine catalysts showed that an ionizable carboxylic function directly linked to the secondary amine catalyst plays an important role in the synthesis of the desired product in good yield. The data obtained has allowed us to suggest, for the first time, that proline, sarcosine, pipecolinic acid and homoproline may act as bifunctional catalysts via a bicyclic enaminolactone species as intermediate. Quantum-mechanical calculations (PM3/COSMO and ab initio 3-21G/COSMO) support this mechanism …
Édition des actes originaux de l'abbaye de Maizières, XIIe siècle
2015
Cette édition a été réalisé dans le cadre de l'ANR Charcis - Chartes cisterciennes du XIIe siècle (dir. B.-M. Tock). Les actes ont été intégrés à la base de données Chartae Galliae (http://www.cn-telma.fr/chartae-galliae/index/) ainsi qu'à la base de données du projet CBMA (http://www.cbma-project.eu/); International audience
Multiscale variation in drought controlled historical forest fire activity in the boreal forests of eastern Fennoscandia
2017
Forest fires are a key disturbance in boreal forests, and characteristics of fire regimes are among the most important factors explaining the variation in forest structure and species composition. The occurrence of fire is connected with climate, but earlier, mostly local-scale studies in the northern European boreal forests have provided little insight into fire-climate relationship before the modern fire suppression period. Here, we compiled annually resolved fire history, temperature, and precipitation reconstructions from eastern Fennoscandia from the mid-16th century to the end of the 19th century, a period of strong human influence on fires. We used synchrony of fires over the network…
Upper limits on the isotropic gravitational-wave background from Advanced LIGO and Advanced Virgo's third observing run
2021
We report results of a search for an isotropic gravitational-wave background (GWB) using data from Advanced LIGO's and Advanced Virgo's third observing run (O3) combined with upper limits from the earlier O1 and O2 runs. Unlike in previous observing runs in the advanced detector era, we include Virgo in the search for the GWB. The results are consistent with uncorrelated noise, and therefore we place upper limits on the strength of the GWB. We find that the dimensionless energy density $\Omega_{\rm GW}\leq 5.8\times 10^{-9}$ at the 95% credible level for a flat (frequency-independent) GWB, using a prior which is uniform in the log of the strength of the GWB, with 99% of the sensitivity comi…
The role of loudness in detection of surprising events in music recordings
2009
The abrupt change of loudness is a salient event that is not always expected by a music listener. Therefore loudness is an important cue when seeking for events in a music stream that could violate human expectations. The concept of expectation and surprise in music has become recently the subject of extensive research, however mostly using symbolic data. The aim of this work is to investigate the circumstances when a change of sound intensity could be surprising for a listener. Then, using this knowledge, we aim to build a computational model that analyzes an audio stream and points to potential violations of human expectation. In order to check the quality of human prediction, an online (…
Virlet – Abbaye de Bellaigue
2021
Büttner S. 2020 : Étude archéologique du chevet et du transept de l’abbatiale de Bellaigue (Virlet – 63), rapport d’étude archéologique du bâti, Auxerre, Centre d’études médiévales Saint-Germain.
Molecular phylogeny of the genus Chondrina (Gastropoda, Panpulmonata, Chondrinidae) in the Iberian Peninsula
2022
[EN] Chondrina Reichenbach, 1828 is a highly diverse genus of terrestrial molluscs currently including 44 species with about 28 subspecific taxa. It is distributed through North Africa, central and southern Europe, from Portugal in the West to the Caucasus and Asia Minor in the East. Approximately 70% of the species are endemic to the Iberian Peninsula constituting its main center of speciation with 34 species. This genus includes many micro endemic taxa, some of them not yet described, confined to limestone habitats (being strictly rock-dwelling species). They are distributed on rocky outcrops up to 2000 m.a.s.l. It is a genus of conical-fusiform snails that differ mainly in shell characte…