Probe transit effect in interferometry of fast moving samples

When a fast moving transparent sample (with a speed close to c) is probed with a laser pulse, some artifacts can occur from data analysis. These artifacts are connected to the transit time of the probe through the sample and can mask the presence of a steep gradient of refractive index in the sample. We study this problem in the case of interferometry. In fact, the problem can affect the femtosecond interferometry of the media under ultrafast ionization by a propagating laser pulse. Two algorithms are introduced: the first based on the phase difference and the second based on visibility. Both algorithms allow for the reconstruction, under suitable assumptions, of an approximated refractive index profile from the distorted fringes.     

Identification of the rainfall–runoff relationship in urban drainage networks

The calibration of conceptual models for the design of urban drainage networks is an important and well-known problem in hydraulic engineering. In this paper the problem is analysed and the use of black-box identification methods is proposed and applied to experimental data. Both linear (ARX and state space) and nonlinear (polynomial and neural NARX) models are considered and their performance in the simulation and prediction of the network flow from rainfall measurements is evaluated.     

Realization of a Reaction-Diffusion CNN Algorithm for Locomotion Control in an Hexapode Robot

In this paper a reaction-diffusion CNN is implemented to generate and adaptively control locomotion in a biologically inspired walking robot. In particular a dedicated CNN development system has been realised to make the mechatronic device able to select, based on sensory stimuli, the most suitable locomotion type according to the environment. The first example of analog implementation of the biological paradigm of the Central Pattern Generator is therefore presented.     

On Stability of Cellular Neural Networks

The main results about stability of cellular neural networks (CNNs) are reviewed. Some of them are extended and reformulated, with the purpose of providing to the CNN designer simple criteria for checking the stability properties. A particular emphasis is given to the conditions for the stability of CNNs described by space-invariant templates.     

日本、韩国化纤及后加工技术交流考察报告

介绍了中国石化集团公司赴日本、韩国考察所了解到的世界化纤市场产品开发和市场需求情况,指出合纤和天然纤维的结合是今后世界化纤市场的发展主流,提出了在中国石化集团公司现有科研基础上加速开发合纤与天然纤维多维多层次立体结构织物、尽快占领市场的建议。     

On Taylor series expansions for waiting times in tandem queues: an algorithm for calculating the coefficients and an investigation of the approximation error

Recently, a Taylor series expansion was developed for expected stationary waiting times in open (max,+)-linear stochastic systems with Poisson input process; these systems cover various instances of queueing networks.As an application, we present an algorithm for calculating the coefficients for infinite capacity tandem queueing networks with discrete service-time distributions. The algorithm works quite efficiently if the random vector of the service times of all servers is concentrated at a small number of atoms. We investigate the relative error of the Taylor approximation by simulation; in many cases, it follows very well a simple expression which holds exactly for independent, exponentially distributed servers.     

Direct observation of the interaction between vortices and dislocations in superconducting crystals by a cryo-Lorentz EM (interaction between vortices and dislocations)

Quantized magnetic flux lines (vortices) in a Nb foil were directly observed in different magnetic fields up to 200 G by a cryo-Lorentz electron microscope. The interaction of vortices with dislocations in the specimen was examined and clarified; edge-on dislocations weakly pin individual vortices at magnetic fields below 100 G. In higher magnetic fields the formation of a regular hexagonal vortex lattice started preferentially at in-plane dislocations. At 200 G the Abrikosov vortex lattice was formed with small domains, whose centre included the dislocations, showing their important role on the formation of the vortex lattice. For a NbTi foil no clear image of vortices could be seen, because the surface was rough due to the formation of fine grains and precipitates.     

Recent Results in the Interpretation of Interference and Lorentz Images of Vortices in Superconductors

The main ideas and approximations underlying the model developed to interpret the principal features of holographic and Fresnel images of superconducting vortices, or fluxons, are briefly reviewed and applied to the exploitation of new experimental setups, like the standard and coherent Foucault techniques. It is also shown how the model can be implemented to interpret effects due to misalignment and/or distortion of the fluxon cores. Finally, the effect of the finite specimen thickness is also taken into account by resorting to the solution of the Ginzburg-Landau equations found by Clem, and by showing that through it a better agreement can be obtained between theoretical and experimental results.     

Solid Acid‐Catalysed Michael‐Type Conjugate Addition of Indoles to Electron‐Poor CC Bonds: Towards High Atom Economical Semicontinuous Processes

In this paper a novel application of solid acid catalysts in the chemoselective Friedel–Crafts (FC) alkylation of indoles is reported. The optimal protocol allows highly functionalised indolyl compounds to be synthesised in excellent yields through conjugate addition of indoles with α,β‐unsaturated ketones and nitro compounds. Finally, the use of commercial Amberlyst‐15 as the heterogeneous catalyst for highly atom efficient continuous and semicontinuous Friedel–Crafts processes is described.