21 research outputs found
Magnesium Exchanged Zirconium Metal−Organic Frameworks with Improved Detoxification Properties of Nerve Agents
UiO-66, MOF-808 and NU-1000 metal-organic frameworks exhibit a differentiated reactivity toward [Mg(OMe)2(MeOH)2]4 related to their pore accessibility. Microporous UiO-66 remains unchanged while mesoporous MOF-808 and hierarchical micro/mesoporous NU-1000 materials yield doped systems containing exposed MgZr5O2(OH)6 clusters in the mesoporous cavities. This modification is responsible for a remarkable enhancement of the catalytic activity toward the hydrolytic degradation of P-F and P-S bonds of toxic nerve agents, at room temperature, in unbuffered aqueous solutions
Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target
Multiplicities of charged pions and unidentified hadrons produced in
deep-inelastic scattering were measured in bins of the Bjorken scaling variable
, the relative virtual-photon energy and the relative hadron energy .
Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and
an isoscalar target (LiD). They cover the kinematic domain in the photon
virtuality > 1(GeV/c, , and . In addition, a leading-order pQCD analysis was performed using the
pion multiplicity results to extract quark fragmentation functions
\pi^0 \pi^0 Production in Proton-Proton Collisions at Tp=1.4 GeV
The reaction pp->pppi0pi0 has been investigated at a beam energy of 1.4 GeV
using the WASA-at-COSY facility. The total cross section is found to be (324 +-
21_systematic +- 58_normalization) mub. In order to to study the production
mechanism, differential kinematical distributions have been evaluated. The
differential distributions indicate that both initial state protons are excited
into intermediate Delta(1232) resonances, each decaying into a proton and a
single pion, thereby producing the pion pair in the final state. No significant
contribution of the Roper resonance N*(1440) via its decay into a proton and
two pions is foundComment: Submitted to PL
Multiplicities of charged kaons from deep-inelastic muon scattering off an isoscalar target
Precise measurements of charged-kaon multiplicities in deep inelastic scattering were performed. The results are presented in three-dimensional bins of the Bjorken scaling variable x, the relative virtual-photon energy y, and the fraction z of the virtual-photon energy carried by the produced hadron. The data were obtained by the COMPASS Collaboration by scattering 160 GeV muons off an isoscalar 6LiD target. They cover the kinematic domain View the MathML source in the photon virtuality, 0.0045 GeV/c2 in the invariant mass of the hadronic system. The results from the sum of the z -integrated K+ and K 12 multiplicities at high x point to a value of the non-strange quark fragmentation function larger than obtained by the earlier DSS fit
Total and differential cross sections of η-production in proton–deuteron fusion for excess energies between Qη = 13 MeV and Qη = 81 MeV
New data on both total and differential cross sections of the production of η mesons in proton–deuteron fusion to He3η in the excess energy region 13.6MeV≤Qη≤80.9MeV are presented. These data have been obtained with the WASA-at-COSY detector setup located at the Forschungszentrum Jülich, using a proton beam at 15 different beam momenta between pp=1.60GeV/c and pp=1.74GeV/c. While significant structure of the total cross section is observed in the energy region 20MeV≲Qη≲60MeV, a previously reported sharp variation around Qη≈50MeV cannot be confirmed. Angular distributions show the typical forward-peaking that was noted earlier. For the first time, it is possible to study the development of these angular distributions with rising excess energy over a wide interval
Vanadium coordination polymers : state of art and perspectives
Vanadium ions are very attractive building units owing to their coordination diversity. In recent years, metal-organic polyhedra (MOP) and metal-organic frameworks (MOFs) have gradually become attractive materials in various fields due to their unique properties. However, despite this, structures based on vanadium ions are scarce. This short perspective review paper describes representative examples of MOP and MOFs based vanadium, focusing on their structure and their applications
Palladium catalysts immobilized in MOF materials active in hydrogenation reactions
Palladium immobilized in metal-organic frameworks (MOF) exhibit promising
catalytic properties in hydrogenation of different unsaturated substrates. Due to
the specific porous and crystalline structure MOFs can contribute in bonding and
activation of organic substrates, increasing catalytic efficiency of Pd@MOF composites.
The superior tunability of MOFs structures enables to design highly selective
catalysts for hydrogenation of different substrates, such as olefins, esters, ketones,
alcohols or alkynes. Due to the synergistic effects of palladium and MOF not only
high activity but also high selectivity can be achieved.
The article presents representative examples of MOF-based palladium catalysts
for hydrogenation to illustrate perspectives, also technological, of their application