Gas-dynamic resistance of a fibre layer

An equation was obtained for calculating the flow of a gas through a layer of parallel cylinders positioned perpendicular to the direction of gas flow by using the plane channel approximation. The broader applicability of the equation for calculating the gas-dynamic resistance of a layer of fibres in comparison to the published data was demonstrated for the given case of gas flow.Branch of the Institute of Energy Problems in Chemical Physics, Chernogolovka. Translated from Khimicheskie Volokna, No. 6, pp. 23–25, November–December, 1992.     

Characteristic Regularities in Condensation of Nickel Layers on the Surface of a Tungsten Single Crystal

Technical Physics Letters - Condensation and adsorption of Ni with a thickness from several tenths of a monoatomic layer to several hundred layers on the surface of a single-crystal W tip has been...     

Intrinsic Quantum Dissipation in Superconducting Weak Links

We evaluate the frequency spectrum for an intrinsic quantum dissipative environment for the Josephson phase φ formed by subgap Andreev bound states in superconducting weak links. We also analyze the problem of macroscopic quantum tunneling (MQT) of φ in highly transparent weak links and identify several MQT regimes. Within the exponential accuracy, we derive the expression for the supercurrent quantum decay rate both at low temperatures and in the vicinity of the quantum-to-classical crossover.     

On One Problem in Multichannel Signal Detection

We consider a statistical problem of detecting a signal with unknown energy in a multichannel system, observed in a Gaussian noise. We assume that the signal can appear in the kth channel with a known small prior probability πk. Using noisy observations from all channels, we would like to detect whether the signal is presented in one of the channels or we observe pure noise. We describe and compare statistical properties of the maximum posterior probability test and optimal Bayes test. In particular, for these tests we obtain limiting distributions of test statistics and define sets of their undetectable signals.     

A comparison of different approaches to estimating measurement uncertainty

The inadmissibility of certain assumptions used in the procedures of the Guide to the Expression of Uncertainty in Measurement and the draft of Supplement 1 to it, which lead to an additional complication of the procedures for estimating uncertainty, which is particularly important for the approach in Supplement 1, is demonstrated. An approach based on the use of a statistical model enables these difficulties to be removed and ensures the required estimation accuracy. __________ Translated from Izmeritel’naya Tekhnika, No. 3, pp. 6–9, March, 2008.     

Nanoelectromechanical switch operating by tunneling of an entire C60 molecule

We present a solid state single molecule electronic device where switching between two states with different conductance happens predominantly by tunneling of an entire C60 molecule. This conclusion is based on a novel statistical analysis of approximately 10(5) switching events. The analysis yields (i) the relative contribution of tunneling, current induced heating and thermal fluctuations to the switching mechanism, (ii) the voltage dependent energy barrier (approximately 100-200 meV) separating the two states of the switch and (iii) the switching attempt frequency, omega0, corresponding to a 2.8 meV mode, which is most likely rotational.