The Nonchiral Fusion Rules in Rational Conformal Field Theories

We introduce a general method in order to construct the nonchiral fusion rules which determine the operator content of the operator product algebra for rational conformal field theories. We are particularly interested in the models of the complementary D-like solutions of the modular invariant partition functions with cyclic center Z _N . We find that the nonchiral fusion rules have a Z _N -grading structure.     

All optical switching in semiconductor microresonators based on pattern selection

We present here a method for selecting optical patterns in a passive semiconductor microresonator, by using a spatial perturbation. A pattern is spontaneously generated in the system, and a switching beam causes this pattern to rotate even if the power in the switching beam is much lower than the power in the pattern. Thus, an all optical switch is realized, that operates at low light levels.     

Segmented gas–liquid flow characterization in rectangular microchannels

We used optical methods such as Laser Induced Fluorescence (LIF) and confocal Laser Scanning Microscopy (LSM) to characterize gas–liquid phase distribution in rectangular microchannels. Using a 2 m long microchannel with a hydraulic diameter of 200 μm enables the precise measurement of important parameters such as liquid slug length, bubble length, pressure drop and film thickness at the wall as well as in the corner of the microchannel for low Capillary numbers (Ca) ranging from 2 × 10⁻⁴ to 1 × 10⁻². This range of Ca was obtained by using different fluid pairs such as ethanol, water and different concentrated aqueous solutions of glycerol in combination with nitrogen.     

Effect of sol concentration on the properties of ZnO thin films prepared by sol-gel technique

ZnO thin films are deposited on the glass substrates by sol-gel drain coating technique by varying the concentration of the sol. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were used to investigate the effect of sol concentration on the crystallinity and surface morphology of the films. The results show that with increase in sol concentration, the value of full width at half maximum (FWHM) of (0 0 2) peak decreases while the strain first increases and then decreases. The sol with higher concentration results in the increase in the grain size. The studies on the optical properties show that the band gap value increases from 3.27 to 3.3 eV when the sol concentration changes from 0.03 to 0.1 M. The photoconductivity studies reveal that the film for 0.05 M sol shows the maximum photoresponse for ultraviolet (UV) wavelength (<400 nm) which is co-related with the deep-level defects. The growth and decay of the photocurrent is found to be slowest for the same film.     

Comparing Theories of Infinite Resistive 1-Networks

Flanders' Hilbert space or finite power theory of infinite networks was extended to 1-networks by Zemanian. A new approach uses approximation by finite networks, a-priori bounds from no-gain properties, and Arzela–Ascoli, in a continuous function space. This paper compares, contrasts and reconciles these existence and uniqueness theories.     

电阻环法模拟测量电子束流的大小和位置

本文介绍了通过测量束流在输运管壁上形成的感应电流，来确定直线感应加速器束流大小、位置的一种方法。实验证明，这种测量方法不会影响电子束在管道中的传输，且测量精度高，装置简单，并可装在真空系统的外面，便于维修。     

Symmetry based properties of the transition metal dichalcogenide nanotubes

The full geometrical symmetry groups (the line groups) of the monolayered, 2Hb and 3R polytypes of the inorganic MoS₂ and WS₂ micro- and nanotubes of arbitrary chirality are found. This is used to find the coordinates of the representative atoms sufficient to determine completely the geometrical structure of the tubes. Then some physical properties which can be deduced from the symmetry are discussed: electron band degeneracies, selection rules, general forms of the second rank tensors and potentials, phonon spectra. Received 13 April 2000     

Modeling the effect of external electric field and current on the stochastic dynamics of ATPase nano-biomolecular motors

The rotary motion of the F₀ part of the F₀F₁-ATPase motor that synthesizes the ATP molecules used by the intracellular stepping motors, such as kinesins, is modeled within a stochastically fluctuating medium via the application of the Langevin dynamics wherein the random intramembrane fluctuations are represented by a white noise. We have investigated the influence of an applied electric field and an applied electric current on this rotary motion, and the subsequent production rate of the ATP molecules. It is seen that the application of a field, or a current, changes both the elastic behavior of the cell membrane and the transmembrane potential. These changes in turn transform the dynamics of the F₀ part of the motor. We have found that at low fields, the role of transmembrane potential becomes significant in the production rate of the ATP molecules, whereas at high fields the changes induced in the surface tension of the membrane also contribute to the production rate of the ATP.     

Broad-band infrared ellipsometry measurements of the c-axis response of underdoped YBa2Cu3O7−δ: Spectroscopic distinction between the normal-state pseudogap and the superconducting gap

We present broad-band infrared ellipsometry measurements of the c-axis dielectric response of underdoped YBa₂Cu₃O_7−d single crystals. Our data provide a clear spectroscopic distinction between the normal-state pseudogap and the superconducting gap. In particular, they establish that different energy scales are underlying the respective redistributions of spectral weight. Furthermore, our data are suggestive of a mutual competition between the two gaps and thus of an extrinsic nature of the pseudogap with respect to superconductivity.