10,677 research outputs found
Migration and Final Location of Hot Super Earths in the Presence of Gas Giants
Based on the conventional sequential-accretion paradigm, we have proposed
that, during the migration of first-born gas giants outside the orbits of
planetary embryos, super Earth planets will form inside the 2:1 resonance
location by sweeping of mean motion resonances (Zhou et al. 2005). In this
paper, we study the subsequent evolution of a super Earth (m_1) under the
effects of tidal dissipation and perturbation from a first-born gas giant (m_2)
in an outside orbit. Secular perturbation and mean motion resonances
(especially 2:1 and 5:2 resonances) between m_1 and m_2 excite the eccentricity
of m_1, which causes the migration of m_1 and results in a hot super Earth. The
calculated final location of the hot super Earth is independent of the tidal
energy dissipation factor Q'. The study of migration history of a Hot Super
Earth is useful to reveal its Q' value and to predict its final location in the
presence of one or more hot gas giants. When this investigation is applied to
the GJ876 system, it correctly reproduces the observed location of GJ876d
around 0.02AU.Comment: 7 pages, 4 figure
Practical geopolitics in cinematic narratives of Marvel’s The Avengers film franchise
This article implies that cinematic narratives project practical geopolitical discourses by using the example of Marvel Cinematic Universe’s success – The Avengers film franchise. The conceptualisation
of imaginary threats in the films that follow the main storyline of the Avengers assembly, determined by the time and the geographic space, give those threats a symbolical manifestation that tends to overlap
with the practical geopolitical notions of American foreign policy, as well as contemporary international politics. The interpretative textual analysis of the films’ narratives and their relations to world politics,
hence, presents the central methodology of this article. The relation between those two has a capacity to transmit a subconscious message to blockbusters’ consumers about preferable practical geopolitical visions in contemporary world politics. Simply, the paper shows how cinematic narratives form an identity that is deeply securitised and able to capture the Zeitgeist of world’s politics.info:eu-repo/semantics/publishedVersio
Optimisation of the structure of the dealing service of the bank with a limited base of counteragents Оптимизация структуры дилинговой службы банка с ограниченной базой контрагентов
The article considers methods of assessment of optimal parameters of the dealing service of the bank with a limited base of counteragents. The methods are based on a mathematical model of microstructure of the interbank currency market [5]. The methods allow identification of optimal parameters of the infrastructure of the dealing service of the bank based on indicators of dynamics of currency rates and market environment of the bank.В статье рассматривается методика оценки оптимальных параметров дилинговой службы банка с ограниченной базой контрагентов. Методика основана на математической модели микроструктуры межбанковского валютного рынка [5]. Методика позволяет определить оптимальные параметры инфраструктуры дилинговой службы банка, исходя из показателей динамики валютных курсов и рыночного окружения банка
Coarse-Grained Modeling of Genetic Circuits as a Function of the Inherent Time Scales
From a coarse-grained perspective the motif of a self-activating species,
activating a second species which acts as its own repressor, is widely found in
biological systems, in particular in genetic systems with inherent oscillatory
behavior. Here we consider a specific realization of this motif as a genetic
circuit, in which genes are described as directly producing proteins, leaving
out the intermediate step of mRNA production. We focus on the effect that
inherent time scales on the underlying fine-grained scale can have on the
bifurcation patterns on a coarser scale in time. Time scales are set by the
binding and unbinding rates of the transcription factors to the promoter
regions of the genes. Depending on the ratio of these rates to the decay times
of the proteins, the appropriate averaging procedure for obtaining a
coarse-grained description changes and leads to sets of deterministic
equations, which differ in their bifurcation structure. In particular the
desired intermediate range of regular limit cycles fades away when the binding
rates of genes are of the same order or less than the decay time of at least
one of the proteins. Our analysis illustrates that the common topology of the
widely found motif alone does not necessarily imply universal features in the
dynamics.Comment: 29 pages, 16 figure
Pressure on charged domain walls and additional imprint mechanism in ferroelectrics
The impact of free charges on the local pressure on a charged ferroelectric
domain wall produced by an electric field has been analyzed. A general formula
for the local pressure on a charged domain wall is derived considering full or
partial compensation of bound polarization charges by free charges. It is shown
that the compensation can lead to a very strong reduction of the pressure
imposed on the wall from the electric field. In some cases this pressure can be
governed by small nonlinear effects. It is concluded that the free charge
compensation of bound polarization charges can lead to substantial reduction of
the domain wall mobility even in the case when the mobility of free charge
carriers is high. This mobility reduction gives rise to an additional imprint
mechanism which may play essential role in switching properties of
ferroelectric materials. The effect of the pressure reduction on the
compensated charged domain walls is illustrated for the case of 180-degree
ferroelectric domain walls and of 90-degree ferroelectric domain walls with the
head-to-head configuration of the spontaneous polarization vectors.Comment: subm. to PRB. This verion is extended by appendi
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