Theory of optical ramsey resonance in three separated fields produced by a corner reflector

In this paper we study the optical Ramsey resonance signal of two-level molecules in three separated fields consisting of one standing wave and two traveling waves of opposite directions with each other. Their separations and phase differences are given by a corner reflector. The transition probability of a molecule that traverses the three interaction regions is calculated by using an optical Bloch vector formalism. It is then integrated over distributions of molecular velocities and positions to evaluate the signal observed with a gas cell. The result is applied to compute the optical Ramsey resonance signal in the absorption line of CH₄ at 3.39 μm. Variations of the Ramsey resonance lineshape and the intensity with the gas pressure and the field intensity are obtained.     

An effective method for removal of the internucleotidic phenylthio group from fully protected oligonucleotides by use of bis(tributyltin) oxide

Several kinds of organotin compounds involving stannyl oximates have been examined as reagents for deblocking the internucleotidic phenylthio group from an appropriately protected S-phenyl diuridine phosphorothioate (1). Among them, bis(tributyltin) oxide was found to be very effective.     

A novel and concise synthesis of spirodienone alkaloids using hypervalent iodine(III) reagents

Intramolecular oxidative coupling reaction of N-protected benzyltetrahydroisoquinoline derivatives using hypervalent iodine(III) reagents was investigated. The use of remarkable combination of phenyliodine bis (trifluoroacetate) (PIFA) and heteropoly acid (HPA) in wet acetonitrile smoothly afforded morphinandienone alkaloids, while neospirinedienone alkaloids were obtained in high yield under anhydrous conditions.     

Combinatorial arc plasma deposition search for Ru-based thin film metallic glass

We have discovered a novel Ru-based thin film metallic glass (TFMG) using combinatorial arc plasma deposition (CAPD). To search for Ru-based TFMG, alloy systems of Ru-Zr-Al, Ru-Zr-Fe and Ru-Zr-Mo were investigated by making libraries. Each library consisted of 1089 CAPD samples deposited on a substrate by CAPD. Composition of each sample is different with each other.The composition and phases of the CAPD samples were measured by energy dispersive X-ray fluorescence spectrometry and X-ray diffractometry, respectively. Results showed the amorphous regions depended on the additive elements Al, Fe or Mo. Compared with the addition of Al, the addition of Fe or Mo exhibited high amorphous forming ability.To evaluate the mechanical properties, the glass transition temperature T_g and the crystallization temperature T_x of the amorphous samples in each Ru-Zr-X alloy, larger samples having the same compositions as the typical amorphous CAPD samples were reproduced by sputtering because the CAPD samples were too small to measure the mechanical properties, T_g and T_x.Ru₆₅Zr₃₀Al₅ and Ru₆₇Zr₂₅Al₈ samples were found to exhibit the better fracture stress and elastic limit than conventional TFMGs, while Ru-Zr-Fe and Ru-Zr-Mo samples were found to be brittle. DSC revealed that the Ru₆₅Zr₃₀Al₅ sample was a TFMG, with a T_g of 902 K and T_x of 973 K.     

Studies on alkylation of acyl anion equivalents: unsymmetrical ketone synthesis by use of diethyl 1-trimethylsilyloxy-alkylphosphonates

Novel acyl anion equivalents, lithiated diethyl 1-trimethylsilyloxy-alkylphosphonates, were successfully alkylated and converted to the corresponding ketones. The mechanism of the alkylation is discussed in connection with the Brook-Wittig rearrangement.     

Spannungsabh?ngigkeit der dielektrischen Eigenschaften von Vulkanisaten aus chloriertem Poly?thylen

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