Some <Emphasis Type="Italic">L</Emphasis>-Function of a Regular Covering of a Graph

Let ₁:KH, ₂:HG and ₂₁:KG be three finite regular coverings of graphs, and let be a representation of the covering transformation group of ₁. We show that the (Bartholdi type) L-function of G associated to the representation of the covering transformation group of ₂₁ induced from is equal to that of H associated to by means of ordinary voltage assignments.Acknowledgments. We would like to thank the referee for many valuable comments and suggestions. This is partially supported by Grant-in-Aid for Science Research (C).Final version received: February 16, 2004     

Direct synthesis of mesoporous titania particles having a crystalline wall

In this study, we demonstrate a novel method for preparing crystallized mesoporous titania by using a low-temperature synthesis technique in the presence of cationic surfactant. XRD patterns showed that the titania particles obtained had both hexagonal structure and a wall with anatase crystalline structure. Transmission electron microscopy (TEM) observation and corresponding electron diffraction pattern confirmed that the calcined particles are crystallized mesoporous titania.     

Novel self-assembling organogelators by combination of a double chain-alkylated L-glutamide and a polymeric head group

This communication introduces a new class of self-assembling organogelators composed of a double chain-alkylated L-glutamide with a polymeric head group.     

On finite element methods for convection dominated phenomena

The aim of this work is to give theoretical justification of several types of finite element approximations to the initial-boundary value problems of first order linear hyperbolic equations. Our approximate scheme is obtained by the piecewise linear continuous finite element method for space variable, x, and the Euler type step by step integration method for time variable, t. An artificial viscosity technique, up-stream type methods are considered within the frame work of L²-theory. The convergence and the error estimate of the approximate solutions to the true one are discussed.     

The six bidecomposable graphs

A graph G is said to be decomposable if G can be decomposed into a cartesian product of two nontrivial graphs. G is bidecomposable if not only G but also its complement G is decomposable. We prove that there are only six bidecomposable graphs; 2K(2), C₄, Q ₃, K(2) ×(K(2) + K(2)) , K(3) × K(3).     

Quantum Control of Coherent ρρ‐Electron Dynamics in Chiral Aromatic Molecules

Control of mobile π‐electrons is one of the fundamental issues in the organic optoelectronics for designing the next generation ultrafast switching devices. The optimal control simulations of coherent π‐electron rotations in (P)‐2,2’‐biphenol, which is the typical nonplanar aromatic molecule with axial chirality, were performed by taking into account two types of the control targets: one is generation of the maximum π‐angular momentum, and the other is the maintaining of the generated unidirectional angular momentum during a setting time duration. The optimal control pulse for each target is designed. The analysis of the simulation results shows that the effective maintaining of the unidirectional angular momentum can be realized by applying 2π pulse to one of the electronic excited states forming the coherent electronic state. The 2π pulse prevents the reverse rotation of the π‐electrons by dumping the excited state population to the ground state and subsequently by pumping the population back to the excited state. The present results provide a theoretical basis for the designing next generation ultrafast switching devices made by organic aromatic molecules.     

Free-flow electrophoresis in a microfabricated chamber with a micromodule fraction separator. Continuous separation of proteins

Continuous free flow electrophoresis of proteins was carried out in a microfabricated free flow electrophoresis (mFFE) module with the 30-μm thick slit of the separation. The newly developed micromodule fraction separator (MFS) was attached to the down-stream end site of the separation chamber of mFFE. By using the MFS, electrolyte solution from the separation chamber was introduced to the peristaltic pump without disturbing the electrolyte solution flow at the bottom side of the chamber. The separation of protein mixture samples was achieved by a hydroxypropylmethylcellulose pretreatment coating of the separation chamber. The pretreatment of the sample chamber effectively suppressed electroosmotic flow. All fractionated samples were collected using the MFS after continuous elecrophoresis and analyzed by reversed-phase HPLC. From the results of HPLC analyses none of the cytochrome c fractions at the other ports revealed cross talk phenomena at adjacent ports. A similar result occurred for the myoglobin. This means that these proteins were completely separated from each other by continuous mFFE, and the MFS functioned efficiently during continuous electrophoresis.     

Evaluation of renal blood volume by PET--the aorta-kidney equilibrium monitored with C15O

Twenty subjects inhaled C15O and its dynamics were monitored to determine when equilibrium between the aorta and kidney occurred. One minute after inhalation, the increase in radioactivity in the aorta paralleled that in the kidney, but thereafter, both declined slowly. The ratio of aorta/kidney radioactivity become constant 1 min after inhalation and remained unchanged for 4 min. Thus renal blood volume can be measured 1 min after inhalation of C15O its distribution in the aorta and kidney has attained equilibrium.     

Regioselective cycloaddition reaction of alkene molecules with the asymmetric dimer on Si(100)c(4 x 2)

We investigated the adsorption states of 2-methylpropene and propene on Si(100)c(4 x 2) using low-temperature scanning tunneling microscopy. We have found that regioselective cycloaddition reactions (di-sigma bond formation) occur between the asymmetric alkene molecules and the asymmetric dimers on Si(100)c(4 x 2). First-principles calculations have elucidated that the regioselectivity is closely related to the structures of precursor species and these precursor species have carbocation-like features. Thus, we conclude that Markovnikov's rule is applicable for the cycloaddition of asymmetric alkene with the asymmetric dimer on Si(100)c(4 x 2).     

Biofabrication of biosilica-glass by living organisms

Biosilicification is an evolutionarily old and widespread type of biomineralization both in unicellular and multicellular organisms, including sponges, diatoms, radiolarians, choanoflagellates, and higher plants. In the last few years combined efforts in molecular biology, cell biology, and inorganic and analytical chemistry have allowed the first insight into the molecular mechanisms by which these organisms form an astonishing variety of siliceous structures that cannot be achieved by chemical methods. Here we report about the present stage of knowledge on structure, biochemical composition, and mechanisms of biosilica formation, focusing our attention particularly on sponges because of the enormous (nano)biotechnological potential of the enzymes involved in this process.