Study on transport of molecules in gel by surface-enhanced Raman spectroscopy

Cellulose - Surface-enhanced Raman spectroscopy (SERS)-based biosensors have recently been extensively developed because of their high sensitivity and nondestructive nature. Conventional SERS...     

Improvements of goodness-of-fit statistics for sparse multinomials based on normalizing transformations

We consider multinomial goodness-of-fit tests for a specified simple hypothesis under the assumption of sparseness. It is shown that the asymptotic normality of the PearsonX ² statistic (X _k ² ) and the log-likelihood ratio statistic (G _k ² ) assuming sparseness. In this paper, we improve the asymptotic normality ofX _k ² andG _k ² statistics based on two kinds of normalizing transformation. The performance of the transformed statistics is numerically investigated.     

Theoretical investigation of carrier envelope phase dependence of all-optical poling with the third- and higher-order nonlinear processes

Dependence of efficiency in all-optical poling with nonlinear processes, up to eighth order, is considered. The explicit form of the nonlinear susceptibility that is responsible for the poling is derived, which shows both CEP and phase mismatch dependence. On the basis of an analysis of pulse propagation in a nonlinear material, it is shown that one can identify the order of nonlinearity that is relevant to the poling process, relying on current technology of CEP stabilization and thin-film growth.     

Asymptotic Approximations for the Distributions of the Multinomial Goodness-of-Fit Statistics under Local Alternatives

N. Cressie and T. R. C. Read (1984, J. Roy. Statist. Soc. B46, 440–464) introduced a class of multinomial goodness-of-fit statistics R^a based on power divergence. All R^a have the same chi-square limiting distribution under null hypothesis and have the same noncentral chi-square limiting distribution under local alternatives. In this paper, we investigate asymptotic approximations for the distributions of R^a under local alternatives. We obtain an expression of approximation for the distribution of R^a under local alternatives. The expression consists of continuous and discontinuous terms. Using the continuous term of the expression, we propose a new approximation of the power of R^a. We call the approximation AE approximation. By numerical investigation of the accuracy of the AE approximation, we present a range of sample size n that the omission of the discontinuous term exercises only slight influence on power approximation of R^a. We find that the AE approximation is effective for a much wider range of the value of a than the other power approximations, except for an approximation method which requires high computer performance.     

Improvement of approximations for the distributions of multinomial goodness-of-fit statistics under nonlocal alternatives

Cressie and Read (J. Roy. Statist. Soc. B 46 (1984) 440–464) introduced the power divergence statistics, R^a, as multinomial goodness-of-fit statistics. Each R^a has a limiting noncentral chi-square distribution under a local alternative and has a limiting normal distribution under a nonlocal alternative. Taneichi et al. (J. Multivariate Anal. 81 (2002) 335–359) derived an asymptotic approximation for the distribution of R^a under local alternatives. In this paper, using multivariate Edgeworth expansion for a continuous distribution, we show how the approximation based on the limiting normal distribution of R^a under nonlocal alternatives can be improved. We apply the expansion to the power approximation for R^a. The results of numerical investigation show that the proposed power approximation is very effective for the likelihood ratio test.     

Image reconstruction of moving acoustic sound sources by temporal reference holography

The feasibility of applying temporal reference holography to detection of moving acoustic radiation sources are examined theoretically and experimentally. Temporal reference holography is proved to be used for the purpose if the width of amplitude spectrum of sound is within a certain range, because the point spread functions of temporal reference hologram coincide with amplitude spectra of sound waves used for recording them.     

Novel hydrophobic/hydrophilic patterning process by photocatalytic Ag nucleation on TiO2 thin film and electroless Cu deposition

A hydrophobic/super-hydrophilic pattern was prepared on a TiO₂ thin film by a new fabrication process. The process consists of five key steps: (1) photocatalytic reduction of Ag⁺ to Ag (nucleation), (2) electroless Cu deposition, (3) oxidation of Cu to CuO, (4) deposition of a self-assembled monolayer (SAM), and (5) photocatalytic decomposition of selected areas of the SAM. A hydrophobic/super-hydrophilic pattern with 500-μm² hydrophilic areas was obtained in this process. It is particularly noteworthy that a UV irradiation time of only 1 s was sufficient for the nucleation step in the patterning process.     

Exceptionally Persistent Nitrogen-Centered Free Radicals. Syntheses, ESR Spectra, Isolation, and X-ray Crystallographic Structures of N-(Arylthio)-2-tert-butyl-4,6-diarylphenylaminyl and N-(Arylthio)-4-tert-butyl-2,6-diarylphenylaminyl Radicals(1)

The preparation, ESR spectra, isolation, and X-ray crystallographic structure of N-(arylthio)-2-tert-butyl-4,6-diarylphenylaminyls (1) and N-(arylthio)-4-tert-butyl-2,6-diarylphenylaminyls (2) are described. The aminyls are generated by PbO(2) oxidation of N-(arylthio)-2-tert-butyl-4,6-diarylanilines and N-(arylthio)-4-tert-butyl-2,6-diarylanilines. The kinetic ESR study shows that the aminyls are quite persistent, even in the presence of oxygen, and exist in the individual radical forms. Among the seventeen aminyls prepared, N-[(4-nitrophenyl)thio]-2-tert-butyl-4,6-diphenylphenylaminyl (1b), N-[(4-nitrophenyl)thio]-2-tert-butyl-4,6-bis(4-chlorophenyl)phenylaminyl (1f), N-[(4-nitrophenyl)thio]-4-tert-butyl-2,6-diphenylphenylaminyl (2b), N-[(4-nitrophenyl)thio]-4-tert-butyl-2,6-bis(4-chlorophenyl)phenylaminyl (2h), and N-[(3,5-dichlorophenyl)thio]-4-tert-butyl-2,6-bis(4-chlorophenyl)phenylaminyl (2j) are isolated as radical crystals. The crystallographic structures of 1b and 2b are determined by the X-ray crystallographic analyses. Aminyls 1 and 2 give similar ESR spectra consisting of 1:1:1 triplets with the a(N) values of 0.921-0.948 mT. Deuteration of the phenyl groups on the anilino benzene ring gives rise to a further splitting of the nitrogen 1:1:1 triplet by the anilino meta (0.126-0.138) and phenylthiyl ortho and para protons (0.077-0.096 mT). Upon recording at high gain, one of the partly deuterated aminyls gives satellite lines due to (33)S isotopes at natural abundance from which a(33)(S) is determined to be 0.51 mT. The ESR parameters for 1 and 2 are compared with those for structurally close N-(arylthio)-2,4,6-triarylphenylaminyl and N-(arylthio)-2,4,6-tri-tert-butylphenylaminyl.     

Chelate formation of zirconium with xylenol orange and semi-xylenol orange

The composition, formation constants, and molar absorptivities of the chelates of zirconium ion wtih xylenol orange and semi-xylenol orange are investigated spectrophotometrically in strong acid medium at ionic strength 3.0 (NaClO₄ and HClO₄). The data obtained were processed with a newly-constructed computer program and with LETAGROP/SPEFO. In the zirconium—xylenol orange system, Zr · H₃ L, Zr· H₄L, and Zr₂ · L are present with logarithmic overall formation constants of 37.80, 38.68, 43.47, and molar absorptivities of 3.10 × 10⁴ (485 nm), 5.98 × 10⁴ (528 nm), 9.50 × 10⁴ (551 nm) I mol^-1 cm^-1, respectively. The chelates Zr · L and Zr · HL were found in the zirconium—semi-xylenol orange system with logarithmic overall formation constants of 26.25 and 27.56, and molar absorptivities of 5.70 × 10⁴ (532 nm) and 8.30 × 10⁴ (535 nm) 1 mol^-1 cm^-1, respectively. Semi-xylenol orange is more sensitive and reliable than xylenol orange as a spectrophotometric reagent for zirconium.