Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailEtude par radiopistage de la territorialité chez le martin pêcheur (Alcedo atthis): cas de deux mâles voisins
Hurner, H; Libois, Roland ULg

in Aves (2005), 42(1-2), 135-141

The kingfisher is generally considered as strongly territorial. However, different pairs are sometimes nesting at very close quarters. Two male kingfishers nesting along the river Meuse (Belgium) at a ... [more ▼]

The kingfisher is generally considered as strongly territorial. However, different pairs are sometimes nesting at very close quarters. Two male kingfishers nesting along the river Meuse (Belgium) at a distance of less than 500 m were radiotagged. Their respective home range (5.2 and 7.2 km) were largely overlapping, some fishing grounds being used simultaneously by both birds. Some kind of territorial defence (a bird chasing its neighbour) has been observed in a very limitid area around the nesting places. [less ▲]

Detailed reference viewed: 66 (0 ULg)
Full Text
See detailEtude par spectrométrie de masse de l'Apparition des ions négatifs par Attachement Electronique Dissociatif dans des molécules polyatomiques.
Locht, Robert ULg

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique. Sciences (1970), LVI(8), 788-817

The appearance of negative ions by dissociative electron attachment has been studied by electron impact on CH4, C2H2, C2H4 and C2H3X (X=F, Cl) using a sector field mass spectrometer. An interpretation has ... [more ▼]

The appearance of negative ions by dissociative electron attachment has been studied by electron impact on CH4, C2H2, C2H4 and C2H3X (X=F, Cl) using a sector field mass spectrometer. An interpretation has been attempted for the measured appearance potentials. The electronaffinity of C2 and C2H is found to be (3.3+/-0.3) eV and (2.3+/-0.2) eV respectively. Some evidence is brought for the existence of excited electronic states in polyatomic negative ions. [less ▲]

Detailed reference viewed: 70 (15 ULg)
Full Text
See detailEtude par Spectrométrie de Masse de la formation d'Ions Négatifs par Attachement Electronique Dissociatif et par le processus de Paire d'Ions.
Locht, Robert ULg

Doctoral thesis (1971)

The aim of this work is to investigate the appearance of negative ions by both the mechanism of Dissociative Electron Attachment (DEA) and Ion Pair processes (IPP) by electron impact. Using the ... [more ▼]

The aim of this work is to investigate the appearance of negative ions by both the mechanism of Dissociative Electron Attachment (DEA) and Ion Pair processes (IPP) by electron impact. Using the appropriate instrumentation (a conventional Nier type mass spectrometer) the best conditions are chosen to ensure ion-molecule collision free ion production (sample pressure, impinging electron beam current), the linearity of the electron energy scale between 2 eV and 100 eV and to minimize mass (and translational kinetic energy) discrimination. The used ionizing electron beam allowed us a resolution of 0.5 eV. An ionization model for both processes is proposed to provide us a method for the measurement of the threshold energy of DEA and IPP. Were necessary the numerical derivation of the ion current (for IPP) and the deconvolution of the ionization efficiency curves (for both DEA and IPP) are applied to increase the accuracy of the threshold energy determination and the resolution of the successive ion producing processes to be observed. DEA and IPP’s are observed and threshold energies are measured and assigned in: (i) diatomic molecules, i.e. H2, CO, NO and O2, (ii) triatomic molecules, i.e. CO2 and CS2 along the reaction paths providing O- and S- and CS-. No CO- ion has been detected. (iii) polyatomic molecules, i.e. CH4, C2H2, C2H4, C2H3F and C2H3Cl. Beside the monoatomic negative ions (H-, C-), diatomic and polyatomic negative ions are detected. For several of these species the electron affinity (EA) of the radical is not known, e.g. CH, C2 and C2H. From the appearance of the corresponding negative ions and threshold measurements this fundamental quantity has been deduced. In the particular case of C2-, the production of the negative ion in an electronically excited state has been put forward for the first time. Dissociation energies of the same diatomic and triatomic negative ions have been deduced and compared with this same magnitude in neutral and positive ionic species. [less ▲]

Detailed reference viewed: 25 (7 ULg)
Full Text
See detailEtude par Spectrométrie de Masse des Mécanismes d'Apparition des Ions Négatifs dans le Méthane.
Locht, Robert ULg

in Extrait du Bulletin de la Société Royale des Sciences de Liège (1966), 35(11-12), 764-777

The negative fragment ions appearing in methane have been investigated using a sector field mass spectrometer. By recording the ionzation efficiency curves of each ion it has been possible to determine ... [more ▼]

The negative fragment ions appearing in methane have been investigated using a sector field mass spectrometer. By recording the ionzation efficiency curves of each ion it has been possible to determine the appearance potentials for several processes. Interpretations of the mechanisms for these critical potentials have been attempted. [less ▲]

Detailed reference viewed: 75 (26 ULg)
See detailEtude par spectrométrie de masse du comportement de complexes organométalliques lors de l'activation par collision
Collette, Caroline ULg

Master's dissertation (1995)

The study by mass spectrometry with electrospray ionization of organometallic complexes was performed in order to elucidate the mechanism of reduction of ions in the gas phase that occurs in the region of ... [more ▼]

The study by mass spectrometry with electrospray ionization of organometallic complexes was performed in order to elucidate the mechanism of reduction of ions in the gas phase that occurs in the region of the cone of the electrospray source. The prospects of this work are a better understanding of the mechanisms of fragmentation of ions in the gas phase in the area of the source and the opportunity to study the reactions of these complexes in the absence of solvent. [less ▲]

Detailed reference viewed: 32 (7 ULg)
See detailEtude par spectrométrie Mössbauer de la distribution du fer dans les fractions minéralogiques séparées de roches lunaires rapportées par Apollo 12
Duchesne, Jules; Depireux, Joseph ULg; Gérard, A. et al

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique. Sciences (1971), 5e série, v. 4(LVII), 1204-1211

Detailed reference viewed: 78 (9 ULg)
Full Text
Peer Reviewed
See detailEtude par spectroscopie de génération de la fréquence somme de l'interface méthanol-platine
Vidal, F.; Busson, B.; Six, C. et al

in J. Phys. IV France (2002), 12

La spectroscopie vibrationnelle non-linéaire par génération de la fréquence somme est une sonde particulièrement adaptée à l'étude des interfaces entre milieux denses. Cette technique a été appliquée à l ... [more ▼]

La spectroscopie vibrationnelle non-linéaire par génération de la fréquence somme est une sonde particulièrement adaptée à l'étude des interfaces entre milieux denses. Cette technique a été appliquée à l'étude de l'interface électrochimique monocristal de platine/solution acide de méthanol, système qui constitue un modèle de pile à combustible, dispositif où l'énergie chimique est directement convertie en énergie électrique. Les propriétés vibrationnelles dépendent fortement de l'orientation cristallographique de l'électrode de platine. [less ▲]

Detailed reference viewed: 37 (1 ULg)
See detailEtude paysagère de la commune de Clavier
Vauchel, Bernadette ULg

Book - Société Nationale Terrienne (1979)

Detailed reference viewed: 31 (2 ULg)
Full Text
See detailEtude phytochimique de plantes d'intérêt cosmétique à Mayotte
Saive, Matthew ULg

Diverse speeche and writing (2014)

Detailed reference viewed: 42 (3 ULg)
See detailEtude phytosociologique de la fagne Wallonne et de la fagne de Cléfay (structure et évolution des associations végétales à sphaignes dans les Hautes-Fagnes de Belgique).
Streel, Maurice ULg

in Académie Royale des Sciences, des Lettres et des Beaux Arts de Belgique. Classe des Sciences. Mémoires. Collection in-4o (1959), XXXI(1), 104

Detailed reference viewed: 23 (3 ULg)