Study of reduction processes over cerium oxide surfaces with atomic hydrogen using ultra accelerated quantum chemical molecular dynamics

Ceria plays an important role in catalysis, due to its ability to store and release oxygen depending on the condition present in the catalyst environment. To analyze the role of ceria in catalytic reactions, it is necessary to know the details of the interaction of ceria surface with environmentally sensitive molecules. This study was conducted using ultra accelerated quantum chemical molecular dynamics. Its purpose was to investigate the reduction process of the (1 1 1) and (1 1 0) surfaces of ceria with atomic hydrogen as well as water desorption mechanisms from the surfaces. This simulation demonstrated that when a high-energy colliding hydrogen atoms are adsorbed on the ceria, it pulls up an O atom from the ceria surfaces and results in the formation of a H₂O molecule. This is the first dynamics simulation related to such reduction processes based on quantum chemistry.     

Spin physics in the high energy hadron productions. A systematic study of the spin asymmetries induced by <Emphasis Type="Italic">pp, γp,ep</Emphasis> and λ<Emphasis Type="Italic">p</Emphasis> collisions

The spin polarizations of hadrons inclusively produced by pp, γp and λp collisions are studied by the quark rearrangement model. The present model is a phenomenological one based on the relativistic spin equations of motion and using the quark distribution functions in hadrons and photon. A general success of the model is demonstrated. We find usefulness of the present formulation for studying the dynamics producing spin asymmetry distributions and the statics determining signs and magnitudes of the spin polarization by reflecting the characteristic quark structure in hadrons.     

Quasi-solid-state dye-sensitized solar cells using room temperature molten salts and a low molecular weight gelator

A dye-sensitized solar cell fabricated using the room temperature molten salt, 1-hexyl-3-methylimidazolium iodide, iodine and a low molecular weight gelator as a quasisolid-state electrolyte showed a 5.0% light-to-electricity conversion efficiency under AM 1.5 irradiation, and high-temperature stability.     

Cyclization of 1,6-enynes with allylic chromate species

[reaction: see text] Treatment of 1,6-enynes with tetramethallylchromate induces a cyclization reaction with concurrent introduction of a methallyl group. A catalytic amount of CrCl(3) combined with methallylmagnesium chloride also achieves this cyclization process. The resultant cyclic organometallic species undergo further functionalization upon reaction with electrophiles.     

Extremely low vertical-emittance beam in the accelerator test facility at KEK

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.     

A practical synthesis of the ABC ring model of ecteinascidins

A practical synthesis of 1,2,3,4,5,6-hexahydro-1,5-imino-10-hydroxy-9-methoxy-3,8,11-trimethyl-3- benzazocin-4-one (3) as an ABC ring model compound of ecteinascidin 743 and safracins from 3-hydroxy-4-methoxy-5-methylbenzaldehyde (7) is described. The overall yield in 15 steps is 27%.     

Synthesis, complexation, and fluorescence behavior of armed crown ethers carrying naphthyl group

Armed crown ethers (1-4) bonding through an amine, amide, ether, or ester linkage to naphthyl group were found to display unique photophysical properties in the presence of guest salts. Complexation of PET fluoroionophores (1a and 1b) with Zn(2+) increased the fluorescence intensities of the host by a factor of 2.4 and 2.7, respectively. (1)H and (13)C NMR analyses of this complexation behavior of 1a revealed that Zn(2+) strongly coordinates with the armed crown nitrogen to cause a dramatic decrease in an intramolecular charge-transfer character. The armed crowns (2 and 3), bonding through an ether or ester linkage to a naphthalene, gave fluorescence quenching with guest thiocyanates. While the amide derivative (4) exhibited high Ba(2+) fluorescence selectivity and in the presence of this cation the host fluorescence intensity was by a factor of 3.69.