Theory of optical analysis of inhomogeneous turbid textures

A trial theory of optical diagnosis of inhomogeneous and turbid materials is firstly proposed, considering mutual photon exchanges due to scattering among conglomerate textures. Including scattering and redistribution of photons between neighboring segments, a collective model of photon flow behaviors is analytically constructed. Employing simple inhomogeneous parameters, a set of equations is formulated to express quasi three-dimensional photon redistribution between segments. The important feature of the theory is a simple framework regarding the complex photon flow to be solved by linear algebra. For qualitative and quantitative analyses of respective components, the simultaneous equations can be solved with their characteristic optical coefficients. Each of the ingredients can be analytically identified and evaluated separately. Some of the calculations are exemplified, to show differences from conventional homogeneous theory. Advantageous applications in medical diagnosis are suggested.     

Determination of the Avogadro constant by counting the atoms in a 28Si crystal

The Avogadro constant links the atomic and the macroscopic properties of matter. Since the molar Planck constant is well known via the measurement of the Rydberg constant, it is also closely related to the Planck constant. In addition, its accurate determination is of paramount importance for a definition of the kilogram in terms of a fundamental constant. We describe a new approach for its determination by counting the atoms in 1 kg single-crystal spheres, which are highly enriched with the 28Si isotope. It enabled isotope dilution mass spectroscopy to determine the molar mass of the silicon crystal with unprecedented accuracy. The value obtained, NA = 6.022,140,78(18) × 10(23) mol(-1), is the most accurate input datum for a new definition of the kilogram.     

Theory of higher-order stark effect of symmetric top molecules

The Stark effect formula for symmetric top molecules, which is correct to the fifth order of an external electric field, is given. The formula is applicable to linear molecules without or with electronic angular momenta coupled in Hund;s case a. Numerical tables are given for the special case of linear molecules without any electronic angular momentum. The effect of centrifugal stretching is considered to the first order. It is shown that our perturbation formula, which is correct to the sixth order of an external electric field, is good even when μE/B is about 1.     

Polarized target asymmetry in π+ photoproduction between 0.3 and 1.0 GeV at 130°

The polarized target asymmetry in the reaction γp → π⁺n has been measured at c.m. angles around 130° for photon energies between 0.3 and 1.0 GeV by detecting the π⁺ only. The asymmetry is compared with recent analyses.     

Laser magnetic resonance measurement of rotational transitions in the metastable a1Δg state of oxygen

Laser magnetic resonance (LMR) for five rotational transitions, J = 4 ← 3, 5 ← 4, 7 ← 6, 8 ← 7, 9 ← 8, of the oxygen molecule ¹⁶O¹⁶O in its metastable state, a¹Δ_g, v = 0, are observed using six fir laser lines. Taking the known values of the g factors, their zero-field frequencies are obtained as 340.0085(6), 424.9810(9), 594.870(1), 679.780(1), and 764.658(1) GHz, respectively. They are fit by $\text{(}\text{E}\text{h}\text{) = B}{}_0\text{[J(J + 1) ? 4] + D}{}_0\text{[J(J + 1) ? 4]}{}^2\text{+ (?1)}{}^{\mathrm{J}}\text{(}\text{1}\text{2}\text{)qJ (J + 1)[J(J + 1) ? 2]}$, where B₀ = 42.50457(10) GHz, D₀ = 153.14(110) kHz, and q = 0.050(90) kHz.     

Tubular Membrane-Like Catalysts for the Oxidative Decomposition of Low-Concentrated Toluene in Air by Periodic Short-Term Plasma Discharge

Plasma Chemistry and Plasma Processing - A porous membrane-like alumina (MA) tube was employed as a catalyst to improve the energy efficiency of the oxidative decomposition of low-concentrated...     

Electrospun nanofiber membranes from polysulfones with chiral selector aimed for optical resolution

Polysulfones with three types of alanyl residue, such as N-α-acetylalanine (Ac-Ala-OH), N-α-benzoylalanine (Bzo-Ala-OH), and N-α-benzyloxycarbonylalanine (Z-Ala-OH), as chiral selectors were prepared by polymer reaction. The resulting modified polysulfones showed chiroptical properties, indicating that the chiral selector residues were successfully introduced into the polysulfone. Nanofiber membranes prepared from the polymeric materials showed adsorption selectivity toward mixtures of racemic Glu, which were adopted as model racemates. Flux values for the nanofiber membranes were enhanced two to three orders of magnitude in comparison with the corresponding typical membranes, but without reduction in permselectivity. In the present study, it is shown that nanofiber is a suitable membrane form not only for molecularly imprinted membranes, but it exhibits enhanced throughput in comparison with typical dense membranes without concurrent reduction in permselectivity.     

Optical ultramicrometer technique utilizing a composite diffraction grating

Precise control of positioning or alignment technique utilizing a “composite diffraction grating” formed by superimposing a pair of gratings is proposed. Positioning accuracy of ±0.1 μm has been achieved in the preliminary experiments using dual transmission gratings. This indicates a novel method of sensitive detection of a displacement.