Lyapunov stability for impulsive control affine systems

This article studies several notions of Lyapunov stability for impulsive control affine systems in the setting of nonautonomous dynamical systems. It presents some relations between the stability of an impulsive control affine system and the stability of its adjacent control system. Stability of compact sets and their components are specially investigated. Lyapunov functionals are employed to characterize each type of stability of closed sets.     

Longitudinal viscous hydrodynamic evolution for the shattered colour glass condensate

We investigate hydrodynamic evolution of the quark-gluon plasma for the colour glass condensate type initial conditions. We solve full second-order viscous hydrodynamic equations in the longitudinal direction to find that non-boost invariant expansion leads to visible deformation on the initial rapidity distribution. The results indicate that hydrodynamic evolution with entropy production from viscosity plays an important role in determining parameters for the initial distributions.     

X ray crystallography of (+)-(R)p methyl phenyl phosphoramidate of ethyl L-phenylalaninate

The absolute configuration of (+)-(R)_p methyl phenyl phosphoramidate of ethyl L-phenylalaninate $\text{1}$ was determined by X ray crystallography.     

Photoinduced Electron‐Transfer Oxidation of Olefins with Molecular Oxygen Sensitized by Tetrasubstituted Dimethoxybenzenes: A Non‐Singlet‐Oxygen Mechanism

α‐Methylstyrene ( 1 ) was photo‐oxidized in the presence of a series of alkylated dimethoxybenzenes as sensitizers in an oxygen‐saturated MeCN solution to afford the cleaved ketone 2 , epoxide 3 , as well as a small amount of the ene product 4 in ca. 1 : 1 : 0.04 ratio. The relative rate of conversion was well‐correlated with the fluorescence quantum yield of sensitizers. Thus, a non‐singlet‐oxygen mechanism is proposed, in which an excited sensitizer is quenched by (ground‐state) molecular oxygen to produce a sensitizer radical cation and a superoxide ion (O), the former of which oxidizes the substrate, while the latter reacts with the resulting olefin radical cation ( 1 ^{+ .}) to give the major oxidation products. Photodurability of such electron‐donating sensitizers is dramatically improved by substituting four aromatic H‐atoms in 1,4‐dimethoxybenzene with Me or fused alkyl groups, which provides us with an environmentally friendly, clean method of photochemical functionalization with molecular oxygen, alternative to the ene reaction via singlet oxygenation.     

Producing cluster states in charge qubits and flux qubits

We propose a method to efficiently generate cluster states in charge qubits, both semiconducting and superconducting, as well as flux qubits. We show that highly entangled cluster states can be realized by a "one-touch" entanglement operation by tuning gate bias voltages for charge qubits. We also investigate the robustness of these cluster states for nonuniform qubits, which are unavoidable in solid-state systems. We find that quantum computation based on cluster states is a promising approach for solid-state qubits.     

200 A GeV Au + Au collisions serve a nearly perfect quark-gluon liquid

A new robust method to extract the specific shear viscosity (η/s)(QGP) of a quark-gluon plasma (QGP) at temperatures T(c) < T ? 2T(c) from the centrality dependence of the eccentricity-scaled elliptic flow v2/ε measured in ultrarelativistic heavy-ion collisions is presented. Coupling viscous fluid dynamics for the QGP with a microscopic transport model for hadronic freeze-out we find for 200 A GeV Au + Au collisions that v2/ε is a universal function of multiplicity density (1/S)(dN(ch)/dy) that depends only on the viscosity but not on the model used for computing the initial fireball eccentricity ε. Comparing with measurements we find 1<4π(η/s)(QGP) < 2.5 where the uncertainty range is dominated by model uncertainties for the values of ε used to normalize the measured v2.     

Vortex shedding behind rings and discs

The wake structure of discs and bluff rings has been investigated experimentally in a wind tunnel. The rings have an inner diameter d_i, and an outer diameter d_o and are classified according to the parameter (d_o + d_i)/(d_o − d_i) = d/w. the ratio of mean diameter to ring width. As d/w → ∞ the flow approaches that around a two dimensional bluff body whereas as d/w tends to unity the body approaches a solid disc. A distinct change in the vortex shedding pattern is found around d/w = 5. Below this critical value velocity fluctuations in the wake have a weak periodic component which is 180° out of phase across a diameter of the body. Above d/w = 5. regular and coherent axisymmetric vortex ring shedding is observed with shedding occurring alternately from the inner and outer circumferences of the bluff body. Flow visualization and conditional averaging of hot-wire data are used to investigate the vortex structure.