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1.
C. Bagnasco P. Ciambelli S. Crescitelli G. Russo 《Reaction Kinetics and Catalysis Letters》1978,8(3):293-300
Cytalysts containing manganese, cobalt or nickel oxides supported on -alumina were physically characterized and tested for the oxidehydrogenation of ethylbenzene. The physical characterization shows surface spinel formation and/or metal oxide segregation for the systems cobalt-alumina and nickelalumina, but Mn2O3 segregation only for the manganese system. The catalytic activity data indicate a promoting effect of Mn2O3 and cobalt aluminate, while the presence of Co3O4 results in a lower activity.
, , -Al2O3, . / - , Mn2O3 . , Mn2O3 , Co3O4) .相似文献
2.
Aamodt K Abelev B Quintana AA Adamová D Adare AM Aggarwal MM Rinella GA Agocs AG Salazar SA Ahammed Z Masoodi AA Ahmad N Ahn SU Akindinov A Aleksandrov D Alessandro B Molina RA Alici A Alkin A Aviña EA Alt T Altini V Altinpinar S Altsybeev I Andrei C Andronic A Anguelov V Anson C Antičić T Antinori F Antonioli P Aphecetche L Appelshäuser H Arbor N Arcelli S Arend A Armesto N Arnaldi R Aronsson T Arsene IC Asryan A Augustinus A Averbeck R Awes TC Aystö J Azmi MD Bach M Badalà A Baek YW 《Physical review letters》2010,105(25):252301
The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies. 相似文献
3.
Aamodt K Abelev B Quintana AA Adamová D Adare AM Aggarwal MM Rinella GA Agocs AG Salazar SA Ahammed Z Masoodi AA Ahmad N Ahn SU Akindinov A Aleksandrov D Alessandro B Molina RA Alici A Alkin A Aviña EA Alt T Altini V Altinpinar S Altsybeev I Andrei C Andronic A Anguelov V Anson C Antičić T Antinori F Antonioli P Aphecetche L Appelshäuser H Arbor N Arcelli S Arend A Armesto N Arnaldi R Aronsson T Arsene IC Asryan A Augustinus A Averbeck R Awes TC Aystö J Azmi MD Bach M Badalà A Baek YW 《Physical review letters》2010,105(25):252302
We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2
相似文献
4.
Bagnasco G. Beneš L. Galli P. Massucci M. A. Patrono P. Turco M. Zima V. 《Journal of Thermal Analysis and Calorimetry》1998,52(2):615-630
Iron(III)-substituted vanadyl phosphate, [Fe(H2O)]0.20VO0.80PO4·2.25H2O (FeVOP), has been prepared and characterized by XRD
and TG/DTA analyses. The new compound is isomorphous with layered tetragonal VOPO4·2H2O (VOP), but it possesses a lower interlayer
distance. Information on the reactivity and surface acidity of both VOP and FeVOP has been obtained by NH3-TPD experiments.
The hydrated materials adsorb high amounts of NH3 (up to 2 mmol g-1). Different ammonia-containing phases are formed, characterized
by lower interlayer distances in comparison with the NH3-free parent compounds. NH3 is intercalated between the layers without
displacement of water. The materials dehydrated by heat treatment at 450°C retain the layered structure but adsorb NH3 only
on the external surface. A wide variety of acid sites, from weak to strong, was observed. A mechanism is proposed for the
NH3- acid sites interaction. SEM micrographs of VOP and FeVOP are shown.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
M. Turco G. Bagnasco L. Lisi P. Ciambelli 《Journal of Thermal Analysis and Calorimetry》1992,38(12):2631-2638
Thermal analysis (TG and DTA) was employed for the characterization of V2O5/TiO2 catalysts supported on high surface area TiO2. The results obtained are consistent with a uniform spreading of vanadium oxide on TiO2 surface for V2O5 content less than 15% by weight.The presence of V2O5 on the surface of TiO2 affects the anatase-rutile phase transition lowering the temperature at which it occurs.DTA measurements, performed on catalysts after many months from the preparation, show the appearance of an exothermic peak in the range 280°–340°C. This signal has been related to the oxidation of V(IV) to V(V) on the catalyst surface.Catalysts characterization, performed by chemical analysis and FT-IR spectroscopy, has confirmed this interpretation.It has been suggested that a slow modification of the catalyst occurs, leading to an increase of the V(IV) content during the time.
Zusammenfassung Zur Charakterisierung von V2O5/TiO2-Katalysatoren auf hochoberflächigem TiO2 Trägermaterial wurde die Thermoanalyse (TG und DTA) angewendet. Für einen V2O5-Gehalt von weniger als 15 Gew.% entsprechen die erhaltenen Ergebnisse einer gleichmäßigen Verteilung des Vanadiumoxides an der TiO2-Oberfläche.Die Gegenwart von V2O5 an der Oberfläche von TiO2 beeinflußt die Anatas-Rutil-Phasenumwandlung, indem sie die zugehörige Temperatur verringert.DTA-Messungen an Katalysatoren mehrere Monate nach ihrer Herstellung zeigten das Auftreten eines exothermen Peaks im Bereich 280°–340°C. Dieses Signal wurde der Oxidation von V(IV) zu V(V) an der Katalysatoroberfläche zugeschrieben.Diese Interpretation konnte durch eine Charakterisierung des Katalysatoren durch chemische Analyse und FT-IR-Spektroskopie bestätigt werden.Es wurde angedeutet, daß der Katalysator mit der Zeit einer langsamen Modifikation unterliegt, die zu einem Ansteigen des V(IV)-Gehaltes führt.相似文献
6.
M. Turco G. Bagnasco G Russo P. Ciambelli P. Patrono M. A. Massucci S. Vecchio 《Journal of Thermal Analysis and Calorimetry》1996,47(1):215-225
The ion exchange technique was employed for the preparation of VO2+ modified titanium phosphates as catalysts for the selective reduction of NO with NH3. The samples were prepared by contacting with a vanadyl sulphate solution different precursor materials, amorphous, crystalline or sodium half exchanged titanium phosphate. The vanadium contents of modified phosphates were in the range 0.08–2.3 wt%. XRD and thermal analysis TG/DTA showed that vanadium loading does not cause structural modification in hydrogen titanium phosphate. A vanadyl containing phase was obtained when half sodium titanium phosphate was employed. The NH3 TPD measurements indicated the presence of a wide distribution of NH3 adsorbing sites with medium-high strength. Catalytic activity measurements were performed under dilute conditions. It was found that the presence of vanadium even in low amounts strongly promote the catalytic activity. 相似文献
7.
Giovanni Bagnasco Claudia Cammarano Maria Turco Serena Esposito Antonio Aronne Pasquale Pernice 《Thermochimica Acta》2008,471(1-2):51-54
Cobalt–silicon mixed oxides with Co/Si ratio of 10/90 (10Co), 20/80 (20Co) and 30/70 (30Co) were prepared by a modified sol–gel method. The materials treated in air at 400 and 600 °C were characterized by SEM and TPR/TPO techniques. TPR measurements showed that in all samples only a fraction of Co was present as Co3O4 and as amorphous silicate and was reducible by H2 within 800 °C, while a part was not reducible under TPR conditions. The fraction of Co not reducible decreased with increasing Co content. A TPO/TPR cycle gave rise to an increase of the fraction of not reducible Co. 相似文献
8.
Bagnasco G. Busca G. Galli P. Larrubia M. A. Massucci M. A. Benes L. Ramis R. Turco M. 《Journal of Thermal Analysis and Calorimetry》2000,61(2):625-636
Hydrated M(III)-vanadyl phosphates (M (III)=Mn, Fe, Ga, Al) have been prepared and studied for water and ammonia adsorption properties by TG/DTA, NH3 TPD, FTIR and XRD techniques. The compounds have the same tetragonal layered structure of VOPO4 ⋅2H2 O, but shorter interlayer distances. Ammonia adsorption leads to intercalation of large amounts (0.19–0.39 mol/mol) of base
between the layers of the materials, without displacement of water. The ammoniated phases obtained from these compounds have
interlayer distances shorter than that of the corresponding precursors. In this connection an interaction mechanism NH3 -host is proposed. Treated at 450°C the materials adsorb ammonia only on the external surface because of the large decrease
of the interlayer distance that prevents NH3 from entering the interlayer space. All M(III)-vanadyl phosphates present a wide distribution of strength of ammonia adsorbing
sites.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
The physico-chemical characterization of magnesium-modified ZSM-5 zeolite catalysts has been performed by differential scanning calorimetry. Evidence has been found of the formation of magnesium oxide and the magnesium spinel phase in alumina-bonded ZSM-5 catalysts. DSC proved a suitable technique for characterization of these systems.
This work was carried out within the Progetto finalizzato Energetica 2 of the National Research Council of Italy. 相似文献
Zusammenfassung Mg-modifizierte ZSM-5-Zeolithkatalysatoren wurden durch DSC charakterisiert. Es wurden Beweise für die Bildung von Magnesiumoxid und Magnesiumspinell in ZSM-5/Aluminiumoxid-Katalysatoren gefunden. DSC hat sich zur Characterisierung dieser Systeme als geeignet erwiesen.
- 3CM-5, . - - . .
This work was carried out within the Progetto finalizzato Energetica 2 of the National Research Council of Italy. 相似文献
10.
The catalytic activity of a chabazite tuff in the reaction 4NON2O+N2O3 was investigated in flow conditions at temperatures between –78 °C and +85 °C. The Ca or Na enriched samples are much more active than the natural tuff; the steady state NO conversion increases with decreasing temperature.
4NON2O+N2O3 –78°C +85°C. , Ca Na , ; NO .相似文献