Onsager coefficients of a Brownian Carnot cycle

We study a Brownian Carnot cycle introduced by Schmiedl and Seifert [Europhys. Lett. 81, 20003 (2008)] from a viewpoint of the linear irreversible thermodynamics. By considering the entropy production rate of this cycle, we can determine thermodynamic forces and fluxes of the cycle and calculate the Onsager coefficients for general protocols, that is, arbitrary schedules to change the potential confining the Brownian particle. We show that these Onsager coefficients contain the information of the protocol shape and they satisfy the tight-coupling condition irrespective of whatever protocol shape we choose. These properties may give an explanation why the Curzon-Ahlborn efficiency often appears in the finite-time heat engines.     

Raman-Nath diffraction by microparticles in water

In Raman-Nath diffraction by water, the intensities of even order light beams are selectively enhanced by suspension of microparticles. The diffracted beams remain for several seconds even after the ultrasonic oscillation stops. These phenomena are elucidated by assuming the laminar arrangement of micropaticles due to the ultrasonic wave.     

Single-electron transport through an individual InAs SAQD embedded in a graded-dope semiconductor nano-pillar

By using the semiconductor nano-pillar with a graded-dope configuration, we implemented the measurement for a single-electron transport through an individual InAs self-assembled quantum dot (SAQD). An atomic-force microscope observation showed that the SAQD had a disk-like shape with a diameter of 30 nm. We succeeded in observing a significant diamagnetic shift of the Coulomb oscillation peak under the magnetic field applied perpendicular to the disk plane. The measurement gave us a lateral confinement energy of 14 meV and an electron effective mass of 0.039, which provided us with quantitative evidence that the constituent material of the observed quantum dot originates from the InAs SAQD.     

Another approach to characterizations of generalized triangle inequalities in normed spaces

In this paper, we consider a generalized triangle inequality of the following type: $$\left\| {x_1 + \cdots + x_n } \right\|^p \leqslant \frac{{\left\| {x_1 } \right\|^p }} {{\mu _1 }} + \cdots + \frac{{\left\| {x_2 } \right\|^p }} {{\mu _n }}\left( {for all x_1 , \ldots ,x_n \in X} \right),$$ where (X, ‖·‖) is a normed space, (µ₁, ..., µ _n ) ∈ ? ⁿ and p > 0. By using ψ-direct sums of Banach spaces, we present another approach to characterizations of the above inequality which is given by [Dadipour F., Moslehian M.S., Rassias J.M., Takahasi S.-E., Nonlinear Anal., 2012, 75(2), 735–741].     

Quasi-two-dimensional magnetic properties of an organic ion-radical salt: 3,3′-diethyl-2,2′-selenacyanine-[TCNQ]2

The temperature dependence of the electric conductivity, the spin-susceptibility and the ESR linewidth of an organic ion-radical salt, 3,3′-diethyl-2,2′-selenacyanine-[TCNQ]₂, was measured to elucidate the quasi-two-dimensional magnetic properties of the salt.     

Total synthesis of (-)-5,6,11-trideoxytetrodotoxin and its 4-epimer

[reaction: see text] The first total synthesis of 5,6,11-trideoxytetrodotoxin (1) and its 4-epimer were achieved. The synthesis is characterized by the stereoselective construction of the quaternary amino carbon center at C8a by an asymmetric transferring Strecker synthesis and the highly efficient conversion of cyanohydrin 4 to 1 via intramolecular cyclization reactions.     

MODIFICATION OF α-CHYMOTRYPSIN USING A WATER-SOLUBLE PHOTO-FENTON REAGENT

Abstract— -Modification of an enzyme, α-chymotrypsin, was examined by using a water-soluble photo-Fenton reagent. By photoirradiation of the enzyme with the reagent, which can occupy a binding site of the enzyme, a tryptophan residue in the vicinity of the active site was oxidized to N -formylkynurenine. Concurrently, the catalytic properties of the enzyme were largely changed: the K _m was increased and the k _catwas decreased. The decrease in k _cat for a specific amide substrate was the most significant among the esters and amides examined. The water-soluble photo-Fenton reagent would be useful to chemically modify relatively limited regions in biomolecules.     

Angular variation of ESR linewidth in organic ionic radical salt: 3,3′-diethyl-2,2′-selenacyanine-[TCNQ]2

Angular dependence of ESR linewidth of 3,3′-diethyl-2,2′-selenacyanine-[TCNQ]₂ single crystal reveals the two-dimensional magnetic nature of the system. The dependence is represented well by ΔH(θ)=α(3 cos²θ?1)²+β sin⁴θ where α and β are temperature-dependent parameters.     

Enantioselective synthesis of d- and l-α-methylcysteine with hydantoinase

A scalable and cost-effective synthesis of d- and l-α-methylcysteine is described. A key step is d-selective cyclization of N-carbamoyl S-tert-butyl-d,l-α-methylcysteine catalyzed by hydantoinase. d-5-tert-Butylthiomethyl-5-methylhydantoin and N-carbamoyl S-tert-butyl-l-α-methylcysteine were obtained with excellent yield and optical purity, and these compounds were easily separated by filtration. After hydrolysis and cleavage of the tert-butyl group, d- and l-α-methylcysteine hydrochloride were obtained.     

Intense THz-radiation from semiconductors under magnetic field irradiated with femtosecond laser pulses

The THz-radiation power from InAs reaches sub-mW level in a 1.7-T magnetic field irradiated with femtosecond laser pulses of 1.5-W average power. The THz-radiation power is related almost quadratically both to the magnetic field and to the excitation laser power. Furthermore, the THz-radiation spectrum is found to be controlled by the excitation pulsewidth, chirp direction of the excitation pulse, and the magnetic field.