471 research outputs found
Sebastian Izquierdo on Universals
The paper deals with the theory of universals of Sebastian Izquierdo, a Spanish Jesuit author working in Rome, as he formulated and defended it in Disputation 17 of his major philosophical work The Lighthouse of Sciences, published in Lyon in 1659. Izquierdo’s discussion centers around three questions: What is universality? Is there some intellect-independent universality? What is the nature of the intellect-dependent universality? Izquierdo’s approach may be seen as a search for the third way between the realism of the Thomists and the Scotists and the nominalism of some Jesuits such as Pedro Hurtado de Mendoza
Arriaga (and Hurtado) against the Baroque Mainstream: The Case of Ens rationis
In 1632 Rodrigo de Arriaga, an important Baroque scholastic thinker, published a textbook in philosophy, of which the last revised and extended edition was published in 1669. Arriaga develops in it a peculiar theory of beings of reason, drawing on Pedro Hurtado de Mendoza, according to which beings of reason are that which is expressed by false judgments. It is a theory quite different from the classical theories held by Francisco Suárez, the Thomists and the majority of Scotists on the one hand, and reductive theories held by Richard Lynch and a growing number of later Baroque authors on the other. In this paper I analyse Arriaga’s theory and deal with the topics of nature, existence, causes, and division of beings of reason
Simple models suffice for the single dot quantum shuttle
A quantum shuttle is an archetypical nanoelectromechanical device, where the
mechanical degree of freedom is quantized. Using a full-scale numerical
solution of the generalized master equation describing the shuttle, we have
recently shown [Novotn\'{y} {\it et al.}, Phys. Rev. Lett. {\bf 92}, 248302
(2004)] that for certain limits of the shuttle parameters one can distinguish
three distinct charge transport mechanisms: (i) an incoherent tunneling regime,
(ii) a shuttling regime, where the charge transport is synchronous with the
mechanical motion, and (iii) a coexistence regime, where the device switches
between the tunneling and shuttling regimes. While a study of the cross-over
between these three regimes requires the full numerics, we show here that by
identifying the appropriate time-scales it is possible to derive vastly simpler
equations for each of the three regimes. The simplified equations allow a clear
physical interpretation, are easily solved, and are in good agreement with the
full numerics in their respective domains of validity.Comment: 23 pages, 14 figures, invited paper for the Focus issue of the New
Journal of Physics on Nano-electromechanical system
Finding the optimum activation energy in DNA breathing dynamics: A Simulated Annealing approach
We demonstrate how the stochastic global optimization scheme of Simulated
Annealing can be used to evaluate optimum parameters in the problem of DNA
breathing dynamics. The breathing dynamics is followed in accordance with the
stochastic Gillespie scheme with the denaturation zones in double stranded DNA
studied as a single molecule time series. Simulated Annealing is used to find
the optimum value of the activation energy for which the equilibrium bubble
size distribution matches with a given value. It is demonstrated that the
method overcomes even large noise in the input surrogate data.Comment: 9 pages, 4 figures, iop article package include
Phase retrapping in aφJosephson junction: onset of the butterfly effect
We investigate experimentally the retrapping of the phase in a
φ
Josephson junction upon return of the junction to the zero-voltage state. Since the Josephson energy profile
U
0
(
ψ
)
in
φ
JJ is a
2
π
periodic double-well potential with minima at
ψ
=
±
φ
mod
2
π
, the question is at which of the two minima
−
φ
or
+
φ
the phase will be trapped upon return from a finite voltage state during quasistatic decrease of the bias current (tilt of the potential). By measuring the relative population of two peaks in escape histograms, we determine the probability of phase trapping in the
±
φ
wells for different temperatures. Our experimental results agree qualitatively with theoretical predictions. In particular, we observe an onset of the butterfly effect with an oscillating probability of trapping. Unexpectedly, this probability saturates at a value different from 50% at low temperatures
Josephson current through a molecular transistor in a dissipative environment
We study the Josephson coupling between two superconductors through a single
correlated molecular level, including Coulomb interaction on the level and
coupling to a bosonic environment. All calculations are done to the lowest,
i.e., the fourth, order in the tunneling coupling and we find a suppression of
the supercurrent due to the combined effect of the Coulomb interaction and the
coupling to environmental degrees of freedom. Both analytic and numerical
results are presented.Comment: 11 pages, 6 figures, to appear in Phys. Rev. B; v3: several misprints
corrected - in particular, sign inconsistencies throughout the paper should
be fixe
Strategie boje s epidemií: vítězové a poražení?
The ongoing covid-19 epidemic has affected the entire world. Somewhat surprisingly, it is not the case that the most successful countries are the richest one, with the best health care. Nor is there a clear link between success and geographical location. Above all, much of the rich Western world has failed so far to protect public health effectively, and so it is appropriate to consider the question why. In this article, I focus mainly on the choice of the basic epidemiological strategy, which I consider to be one of the key factors of success or failure of many countries. I further criticize the view that the protection of human lives would harm the economy or other important values of societies
Co měl Laozi v úmyslu říci? Chanova hermeneutická výzva
V tomto článku se zamýšlím nad možností „správné“ (objektivní, adekvátní) interpretace Dao De Jingu (DDJ). Zamyšlení nad „komunikační situací“ vede k rozlišení několika základních prvků (autor, text, interpret, adresát). K jednotlivým prvkům stručně shrnuji současný stav interpretačního úsilí odborníků na DDJ (opíraje se především o článek A. Chana). Kontroverzní povaha výsledků současného bádání nás nemá vést ke skepticismu „integrativní hermeneutiky“, která na adekvátní interpretaci rezignuje. Je možné se i nadále držet principů „rekonstruktivní hermeneutiky“, která spatřuje adekvátní interpretaci jakožto svůj cíl
Absolute rate coefficients for photorecombination and electron-impact ionization of magnesium-like iron ions from measurements at a heavy-ion storage ring
Rate coefficients for photorecombination (PR) and cross sections for
electron-impact ionization (EII) of Fe forming Fe and
Fe, respectively, have been measured by employing the electron-ion
merged-beams technique at a heavy-ion storage ring. Rate coefficients for PR
and EII of Fe ions in a plasma are derived from the experimental
measurements. Simple parametrizations of the experimentally derived plasma rate
coefficients are provided for use in the modeling of photoionized and
collisionally ionized plasmas. In the temperature ranges where Fe is
expected to form in such plasmas the latest theoretical rate coefficients of
Altun et al. [Astron. Astrophys. 474, 1051 (2007)] for PR and of Dere [Astron.
Astrophys. 466, 771 (2007)] for EII agree with the experimental results to
within the experimental uncertainties. Common features in the PR and EII
resonance structures are identified and discussed.Comment: 12 pages, 6 figures, 3 tables, submitted for publication to Physical
Review
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