869,962 research outputs found
A stronger concept of K-stability
In this paper, by introducing a wider class of one-parameter group actions
for test configurations, we have a stronger form of the definition of
K-stability. This allows us to obtain some key step of my preceding work in
proving that constant scalar curvature polarization implies K-stability for
polarized algebraic manifolds
Multiscale non-adiabatic dynamics with radiative decay, case study on the post-ionization fragmentation of rare-gas tetramers
In this supplementary material, we recollect, for reader's convenience, the
general scheme of suggested multiscale model (Sec. 1), and basic informations
about approaches used for pilot study: a detailed description of the
interaction model (Sec. 2) and dynamical methods used for the dark dynamics
step (Sec. 3) reported previously in two preceding studies [1, 2]. In addition,
a detailed description of the treatment of radiative processes is also given
(Sec. 4).Comment: supplementary material for parent paper; 9 pages, 1 figure; corrected
formulae and misleading notation in Sec.4 (pages 7 and 8
Silver(I) triflate-catalyzed protocol for the post-ugi synthesis of spiroindolines
A silver(I) triflate-catalyzed protocol for the post-Ugi synthesis of tetracyclic spiroindolines has been developed. The protocol worked best for indole-3-carbaldehyde-derived Ugi adducts obtained using anilines and 3-aryl propiolic acids. Thus, it is complementary to the previous cationic gold-catalyzed procedure that was developed for analogues Ugi substrates derived from aliphatic amines and 3-alkyl propiolic acids. Furthermore, we have demonstrated that under our new settings this domino Friedel-Crafts ipso cyclization / imine trapping process could be efficiently combined with the preceding four-component Ugi reaction into a two-step one-pot transformation
Measuring the speed of the conscious components of recognition memory: Remembering is faster than knowing.
Three experiments investigated response times (RTs) for remember and know responses in recognition memory. RTs to remember responses were faster than RTs to know responses, regardless of whether the remember–know decision was preceded by an old/new decision (two-step procedure) or was made without a preceding old/new decision (one-step procedure). The finding of faster RTs for R responses was also found when remember–know decisions were made retrospectively. These findings are inconsistent with dual-process models of recognition memory, which predict that recollection is slower and more effortful than familiarity. Word frequency did not influence RTs, but remember responses were faster for words than for nonwords. We argue that the difference in RTs to remember and know responses reflects the time taken to make old/new decisions on the basis of the type of information activated at test
Fine- and hyperfine-structure effects in molecular photoionization: II. Resonance-enhanced multiphoton ionization and hyperfine-selective generation of molecular cations
Resonance-enhanced multiphoton ionization (REMPI) is a widely used technique
for studying molecular photoionization and producing molecular cations for
spectroscopy and dynamics studies. Here, we present a model for describing
hyperfine-structure effects in the REMPI process and for predicting hyperfine
populations in molecular ions produced by this method. This model is a
generalization of our model for fine- and hyperfine- structure effects in
one-photon ionization of molecules presented in the preceding companion
article. This generalization is achieved by covering two main aspects: (1)
treatment of the neutral bound-bound transition including hyperfine structure
that makes up the first step of the REMPI process and (2) modification of our
ionization model to account for anisotropic populations resulting from this
first excitation step. Our findings may be used for analyzing results from
experiments with molecular ions produced by REMPI and may serve as a
theoretical background for hyperfine-selective ionization experiments
One-Membrane P Systems with Activation and Blocking of Rules
We introduce new possibilities to control the application of rules based on
the preceding applications, which can be de ned in a general way for (hierarchical) P
systems and the main known derivation modes. Computational completeness can be
obtained even for one-membrane P systems with non-cooperative rules and using both
activation and blocking of rules, especially for the set modes of derivation.
When we allow the application of rules to in
uence the application of rules in previous
derivation steps, applying a non-conservative semantics for what we consider to be a
derivation step, we can even \go beyond Turing"
Density-functional study of hydrogen chemisorption on vicinal Si(001) surfaces
Relaxed atomic geometries and chemisorption energies have been calculated for
the dissociative adsorption of molecular hydrogen on vicinal Si(001) surfaces.
We employ density-functional theory, together with a pseudopotential for Si,
and apply the generalized gradient approximation by Perdew and Wang to the
exchange-correlation functional. We find the double-atomic-height rebonded D_B
step, which is known to be stable on the clean surface, to remain stable on
partially hydrogen-covered surfaces. The H atoms preferentially bind to the Si
atoms at the rebonded step edge, with a chemisorption energy difference with
respect to the terrace sites of >sim 0.1 eV. A surface with rebonded single
atomic height S_A and S_B steps gives very similar results. The interaction
between H-Si-Si-H mono-hydride units is shown to be unimportant for the
calculation of the step-edge hydrogen-occupation. Our results confirm the
interpretation and results of the recent H_2 adsorption experiments on vicinal
Si surfaces by Raschke and Hoefer described in the preceding paper.Comment: 13 pages, 8 figures, submitted to Phys. Rev. B. Other related
publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm
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