Application of X-ray fluorescence holography to the analysis of the interior and surface of an yttrium oxide thin film

We report on the characterization of a thin film of yttrium oxide by X-ray fluorescence holography. The sample has a layered structure with an YO base layer and an oxidized Y₂O₃ surface. Both layers are clearly observed in the atomic image reconstructions, and their local structure is analyzed. We show that by using incident energies close to the absorption edge of the fluorescing atom, it becomes possible to observe the thin surface layer clearly, even next to a base layer containing the same fluorescing element.     

Electrical Properties of Silver Photodoped Amorphous Red Phosphorus

Abstract

Effects of photodoping and thermal doping of silver into sputtered amorphous red phosphorus films (a-P_red) on the electrical properties are studied. The d. c. efectrical conductivity of the photodoped a-p_red at room temperature is about 1×10^?5 Scm^?1 which is a very high value comparing with that of the undoped a-p_red (1×10^?14 Scm^?1). The activation energy for the conduction of the photodoped a-P_red is lower than that of the a-p^red. In contrast, the activation energy of the thermally doped a-p_red is essentially the same as that of the undoped a-p_red. SEM-EDX analyses show that colloidal silver was deposited in the thermally doped a-p_red but not in the photodoped a-p_red. It seems that the photo-doping involves the ionization process of silver by illumination, i.e., Ag^o → Ag⁺ + e^?.     

Single structure widely distributed in a GeTe-Sb2Te3 pseudobinary system: a rock salt structure is retained by intrinsically containing an enormous number of vacancies within its crystal

GeTe(1-x)-Sb2Te3(x) sputtered amorphous film was crystallized into a simple NaCl-type structure through instantaneous laser irradiation over a wide composition range from x = 0 to at least 2/3. When the ratio of Sb2Te3 increases, a vacancy is generated at every Na site for two Sb atoms. The fraction of vacancies, v(x), changes according to x/(1 + 2x), and the cubic root unit cell volume varies with a strong correlation to v(x). Through these created vacancies, valence electrons provided by adjacent Ge/Sb and Te atoms remain constant regardless of the composition, ensuring that these electrons occupy predominantly the bonding molecular orbitals. This results in crystal chemical stability, with the closed shell p-p bondings in the valence electrons arranging the crystal's atomic configuration into an NaCl-type structure.     

Implementation of quantum gate operations in molecules with weak laser fields

We numerically propose a way to perform quantum computations by combining an ensemble of molecular states and weak laser pulses. A logical input state is expressed as a superposition state (a wave packet) of molecular states, which is initially prepared by a designed femtosecond laser pulse. The free propagation of the wave packet for a specified time interval leads to the specified change in the relative phases among the molecular basis states, which corresponds to a computational result. The computational results are retrieved by means of quantum interferometry. Numerical tests are implemented in the vibrational states of the B state of I2 employing controlled-NOT gate, and 2 and 3 qubits Fourier transforms. All the steps involved in the computational scheme, i.e., the initial preparation, gate operation, and detection steps, are achieved with extremely high precision.     

Alkyne-coordinating tridentate ligands: structural properties and reactivity of their rhodium complexes

Complexes of novel alkyne-chelating tridentate ligands bound to a rhodium atom were isolated and characterised. The present alkyne-rhodium complex underwent dimerisation simply by heating to afford the unprecedented cyclobutadiene dirhodium complex. It is also found that the ligands at the trans positions influence the π-coordination of alkynes.     

New triterpenoid saponins from leaves of Panax japonicus (3). Saponins of the specimens collected in Miyazaki prefecture

Two new dammarane-type triterpenoid saponins, chikusetsusaponin LM1 (1), chikusetsusaponin LM2 (2), and three known triterpenoid saponins, ginsenoside Re (3), ginsenoside Rg1 (4), ginsenoside F3 (5), were isolated from the leaves of P. japonicus C. A. Meyer collected in Miyazaki prefecture, Japan. The structures of new chikusetsusaponins were elucidated on the basis of spectroscopic and physicochemical evidences.     

New triterpenoid saponins from fruits specimens of Panax japonicus collected in Kumamoto and Miyazaki prefectures (1)

Seven new dammarane-type triterpenoid saponins, chikusetsusaponin FK1 (1), chikusetsusaponin FK2 (2), chikusetsusaponin FK3 (3), chikusetsusaponin FK4 (4), chikusetsusaponin FK5 (5), chikusetsusaponin FK6 (6), and chikusetsusaponin FK7 (7), and eleven known triterpenoid saponins, ginsenoside Rb3 (9), ginsenoside Rc (10), chikusetsusaponin VI (11), ginsenoside Re (12), ginsenoside Rg1 (13), pseudo-ginsenoside RS1 (14), notoginsenoside R1 (15), chikusetsusaponin L5) (17), chikusetsusaponin L10 (18), chikusetsusaponin IVa (19), and chikusetsusaponin V (20), were isolated from the fruits of Panax japonicus C. A. MEYER, collected in Kumamoto prefecture, Japan, and two new dammarane-type triterpenoid saponin, chikusetsusaponin FK5 (5) and chikusetsusaponin FM1 (8), and five known triterpenoid saponins, ginsenoside Rb3 (9), ginsenoside Rc (10), ginsenoside Re (12), ginsenoside Rg1 (13), and floralquinquenoside E (16), were isolated from the fruits of P. japonicus C. A. MEYER, collected in Miyazaki prefecture, Japan. The structures of new chikusetsusaponins were elucidated on the basis of chemical and physicochemical evidences.     

Analysis of detected signal performance in multi-tracks of optical disk memory using convex-shaped recording mark

The possibility of multi-valued optical disk memory by using a convex-shaped recording mark fabricated by two-photon absorption is investigated. We fabricate a numerical model for convex-shaped recording marks and evaluate the signal characteristics in terms of the signal-to-noise ratio (SNR). The numerical results show that 6 bit data can be realized when the acceptable average SNR is 2 and a length of the mark is 4T.     

Telluroxide elimination by direct oxidation of alkyl phenyl telluride

Treatment of sec-alkyl phenyl tellurides, except for the cyclohexyl system, with m-chloroperbenzoic acid(MCPBA) in diethyl ether readily afforded the corresponding olefins in good yields presumably via telluroxide elimination together with small amounts of alcohols and ketones. In the pri-alkyl and cyclohexyl cases the adducts between MCPBA and the tellurides were isolated as stable organotellurium(IV) compounds which gave similar elimination products by neat pyrolysis at 220–2500°C.     

Studies on medicinal resources from livestock. I. Anti-allergic effects of pig bile. (1)

Anti-allergic activities of animal biles and commercially available bile acids were evaluated in experimental allergic disease models. Pig bile exhibited marked preventive effects on the models of delayed-type hypersensitivity (type IV allergy), picryl chloride-induced contact dermatitis (PC-CD) and sheep red blood cells (SRBC)-induced footpad swelling in mice. Fel ursi (dried bear gallbladder) also had an inhibitory effect on PC-CD, whereas ox bile, chicken bile and bile acids had no effect on ether of the models.