Super-Kadomtsev—Petviashvili hierarchy and super-Grassmann manifold

The super-Kadomtsev-Petviashvili (SKP) hierarchy is introduced, and the general solutions are explicitly represented in terms of a superdeterminant. It is proved that the SKP hierarchy can be regarded as a dynamical system on a super-Grassmann manifold of infinite dimensions.     

Energy distribution curves of ultrafast laser-induced field emission and their implications for electron dynamics

Energy distribution curves of laser-induced electron pulses from a tungsten tip have been measured as a function of tip voltage and laser power. Electron emission via tunneling through and/or excitation over the surface barrier from photoexcited nonequilibrium electron distributions are clearly observed. The spectral shapes largely vary with the emission processes and are strongly affected by electron dynamics. Simulations successfully reproduce the spectra, thus allowing direct insight into the involved electron dynamics and revealing the temporal tunability of electron emission via the two experimental parameters. These results should be useful to optimize the pulse characteristics for many applications based on ultrafast laser-induced electron emission.     

Gasification characteristics of woody biomass in the packed bed reactor

Gasification technology is recognized as one of the possibilities for utilizing biomass effectively. This study focused on woody biomass gasification fundamentals, using a bench-scale packed-bed reactor. In this experiment, pellets of black pine were gasified, using air as the oxidizing agent. Gasification tests were carried out under both updraft and downdraft conditions. Temperature distributions and compositions of syngas inside the gasifier were continuously monitored during gasification experiments at several ports on the wall of the reactor. The syngas at the exit of the gasifier was also sampled to estimate the amount of tar. Lower heating values of the syngas under updraft and downdraft conditions were 4.8 and 3.8 MJ/m³N, respectively. It was easier to control the height of the packed bed under the downdraft condition than under the updraft condition. Under the updraft condition, a bridging phenomenon occurred. Tar generation under the downdraft condition was lower than that under the updraft condition. This is because tar passes through a partial combustion zone or higher temperature zone in the downdraft gasifier.     

Noble Metal Sintering Suppression Technology in Three-way Catalyst: Automotive Three-way Catalysts with the Noble Metal Sintering Suppression Technology Based on the Support Anchoring Effect

This paper reviews the progress in our development of the three-way catalyst with a noble metal sintering suppression technology based on the support anchoring effect. The catalytic activity on this catalyst is far superior to the conventional catalyst, but with lower noble metal loading.     

Theoretical and computational studies of organometallic reactions: successful or not?

Theoretical and computational methods are powerful in studying transition metal complexes. Our theoretical studies of C–H σ‐bond activation of benzene by Pd(II)–formate complex and that of methane by Ti(IV)‐imido complex successfully disclosed that these reactions are understood to undergo heterolytic σ‐bond activation and the driving force is the formation of strong O–H and N–H bonds in the former and the latter, respectively. Orbital interactions are considerably different from those of σ‐bond activation by oxidative addition. The transmetallation, which is a key process in the cross‐coupling reaction, is understood to be heterolytic σ‐bond activation. Our theoretical study clarified how to accelerate this transmetallation. Also, we wish to discuss weak points in theoretical and computational studies of large systems including transition metal elements, such as the necessity to incorporate solvation effect and to present quantitatively correct numerical results. The importance of solvation effects is discussed in the oxidative addition of methyliodide to Pt(II) complex which occurs in a way similar to an S_N2 substitution. To apply the CCSD(T) (coupled cluster singles and doubles with perturbative triples correction) method, which is the gold standard of electronic structure theory, to large system, we need to reduce the size of the system by employing a small model. But, such modeling induces neglects of electronic and steric effects of substitutents which are replaced in the small model. Frontier‐orbital‐consistent quantum‐capping potential (FOC‐QCP) was recently proposed by our group to incorporate the electronic effects of the substituents neglected in the modeling. The CCSD(T) calculation with the FOC‐QCP was successfully applied to large systems including transition metal elements. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 10: 000–000; 2010: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.200900019     

Novelty Filtering Using Phase Conjugate Wave in Organic Dye-Doped Polymer Films

A real-time detection of a moving object was demonstrated by taking the subtraction between cross-polarized phase conjugate waves with fast and slow response times with two kinds of dye-doped phase conjugators. One consists of superposed films of an erythrosin-B-doped film and a methyl-orange-doped film, and the other is a film dispersed with both dyes. The relative phase between cross-polarized phase conjugate waves by the both dye-dispersed films was stable.     

Palladium‐catalyzed three‐component coupling polycondensation of aromatic diiodide,aromatic bis(boronic acid propanediol ester), and norbornadiene: A new route for poly(p‐phenylene vinylene)

A novel synthetic method for soluble precursor polymers of poly(p‐phenylene vinylene) (PPV) derivatives by the palladium‐catalyzed three‐component coupling polycondensation of aromatic diiodides, aromatic bis(boronic acid) derivatives, and norbornadiene is described. For example, the polymerization of 1,4‐diiodo‐2,5‐dioctyloxybenzene, benzene‐1,4‐bis(boronic acid propanediol ester), and norbornadiene at 100 °C for 3 days provided a polymer consisting of the three monomer units in a 97% yield (number‐average molecular weight = 3100, weight‐average molecular weight/number‐average molecular weight = 1.37). A derivative of PPV was produced smoothly by the retro Diels–Alder reaction of the polymer both in a dodecyloxybenzene solution and in a film at 200 °C in vacuo. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3403–3410, 2005     

Equivalents of the Riemann hypothesis

We obtain necessary and sufficient conditions for the Riemann hypothesis for the Riemann zeta-function, in terms of the functional distribution of quadratic Dirichlet L-functions. Received: 29 November 2004