623 research outputs found
The one-way CNOT simulation
In this paper we present the complete simulation of the quantum logic CNOT
gate in the one-way model, that consists entirely of one-qubit measurements on
a particular class of entangled states.Comment: 7 pages, 2 figure
Theory of high-order harmonic generation from molecules by intense laser pulses
We show that high-order harmonics generated from molecules by intense laser
pulses can be expressed as the product of a returning electron wave packet and
the photo-recombination cross section (PRCS) where the electron wave packet can
be obtained from simple strong-field approximation (SFA) or from a companion
atomic target. Using these wave packets but replacing the PRCS obtained from
SFA or from the atomic target by the accurate PRCS from molecules, the
resulting HHG spectra are shown to agree well with the benchmark results from
direct numerical solution of the time-dependent Schr\"odinger equation, for the
case of H in laser fields. The result illustrates that these powerful
theoretical tools can be used for obtaining high-order harmonic spectra from
molecules. More importantly, the results imply that the PRCS extracted from
laser-induced HHG spectra can be used for time-resolved dynamic chemical
imaging of transient molecules with temporal resolutions down to a few
femtoseconds.Comment: 10 pages, 5 figure
B-physics computations from Nf=2 tmQCD
We present an accurate lattice QCD computation of the b-quark mass, the B and
Bs decay constants, the B-mixing bag-parameters for the full four-fermion
operator basis, as well as estimates for \xi and f_{Bq}\sqrt{B_q} extrapolated
to the continuum limit and the physical pion mass. We have used Nf = 2
dynamical quark gauge configurations at four values of the lattice spacing
generated by ETMC. Extrapolation in the heavy quark mass from the charm to the
bottom quark region has been carried out using ratios of physical quantities
computed at nearby quark masses, having an exactly known infinite mass limit.Comment: 7 pages, 4 figures, presented at the 31st International Symposium on
Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, German
Effect of the surface chemical composition and of added metal cation concentration on the stability of metal nanoparticles synthesized by pulsed laser ablation in water
Metal nanoparticles (NPs) made of gold, silver, and platinum have been synthesized by means of pulsed laser ablation in liquid aqueous solution. Independently from the metal nature, all NPs have an average diameter of 10 ± 5 nm. The ζ-potential values are:-62 ± 7 mV for gold,-44 ± 2 mV for silver and-58 ± 3 for platinum. XPS analysis demonstrates the absence of metal oxides in the case of gold and silver NPs. In the case of platinum NPs, 22% of the particle surface is ascribed to platinum oxidized species. This points to a marginal role of the metal oxides in building the negative charge that stabilizes these colloidal suspensions. The investigation of the colloidal stability of gold NPs in the presence of metal cations shows these NPs can be destabilized by trace amounts of selected metal ions. The case of Ag+ is paradigmatic since it is able to reduce the NP ζ-potential and to induce coagulation at concentrations as low as 3 μM, while in the case of K+ the critical coagulation concentration is around 8 mM. It is proposed that such a huge difference in destabilization power between monovalent cations can be accounted for by the difference in the reduction potential
Rescate de embriones maduros en una población segregante del híbrido interespecífico de Zea mays L. x Zea diploperennis 1.
El objetivo de este trabajo fue probar la respuesta al cultivo in vitro de embriones maduros de material segregante de un híbrido entre Zea mays y Zea diploperennis y realizar su posterior seguimiento hasta la etapa de fructificación. Los explantos se cultivaron en dos medios (Monnier y Randolph y Cox). El material genético respondió exitosamente en ambos medios observándose una mayor supervivencia de plántulas durante la etapa de aclimatación en las provenientes de los embriones cultivados en el medio Randolph y Cox. Las plantas alcanzaron la etapa de fructificación, pero no se logró obtener dos generaciones al año dado que los granos resultaron vanos.Director: Lic. Ofelia Naab e Ing. Agr. Carmen Torroba, Cátedra de Biología
Ag-based synergistic antimicrobial composites. A critical review
The emerging problem of the antibiotic resistance development and the consequences that the health, food and other sectors face stimulate researchers to find safe and effective alternative methods to fight antimicrobial resistance (AMR) and biofilm formation. One of the most promising and efficient groups of materials known for robust antimicrobial performance is noble metal nanoparticles. Notably, silver nanoparticles (AgNPs) have been already widely investigated and applied as antimicrobial agents. However, it has been proposed to create synergistic composites, because pathogens can find their way to develop resistance against metal nanophases; therefore, it could be important to strengthen and secure their antipathogen potency. These complex materials are comprised of individual components with intrinsic antimicrobial action against a wide range of pathogens. One part consists of inorganic AgNPs, and the other, of active organic molecules with pronounced germicidal effects: both phases complement each other, and the effect might just be the sum of the individual effects, or it can be reinforced by the simultaneous application. Many organic molecules have been proposed as potential candidates and successfully united with inorganic counterparts: polysaccharides, with chitosan being the most used component; phenols and organic acids; and peptides and other agents of animal and synthetic origin. In this review, we overview the available literature and critically discuss the findings, including the mechanisms of action, efficacy and application of the silver-based synergistic antimicrobial composites. Hence, we provide a structured summary of the current state of the research direction and give an opinion on perspectives on the development of hybrid Ag-based nanoantimicrobials (NAMs)
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