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161.
Tajima N Mizuno Y Hamamoto K Arakawa H Maeda M 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2006,47(6):254-257
A new and simple analytical method for glycarbylamide (GB) based on the formation of nickel chelate was developed. The proposed method is as follows: sample solution is mixed with 0.08 mmol/L nickel nitrate in 0.2 mol/L carbonate buffer (pH 9.0), and the absorbance is measured at 290 nm. Under the optimal conditions, GB could be determined in the concentration range from 0.13 microg/mL to 2.6 microg/mL (r = 0.9999). Using this method for HPLC post column reaction, GB levels in chicken liver extracts could be determined. The recovery of GB was 79.4% (RSD=2.6%, n=3) and the quantitation limit was 30 ng/g. The apparent molar extinction coefficient (epsilon) of the GB-nickel complex was 8.5 x 10(3). The molar ratio of the complex is GB: nickel ion = 2:1. 相似文献
162.
163.
Yoichi Sato Keisuke Shinozaki Hiroyuki Sugita Kazuhisa Mitsuda Noriko Y. Yamasaki Yoh Takei Takao Nakagawa Ryuichi Fujimoto Masahide Murakami Shoji Tsunematsu Kiyomi Otsuka Seiji Yoshida Kenichi Kanao Katsuhiro Narasaki 《低温学》2012,52(4-6):158-164
Astro-H is the Japanese X-ray astronomy satellite planned for launch in 2014. The Soft X-ray Spectrometer (SXS) onboard Astro-H, is a high energy resolution spectrometer utilizing an X-ray micro-calorimeter array, which is operated at 50 mK by the ADR with the 30-L superfluid liquid helium (LHe). The mechanical cryocoolers, 4 K-class Joule Thomson (JT) cooler and 20 K-class double-staged Stirling (2ST) cooler are key components to achieve a LHe lifetime for over 3 years in orbit (5 years as a goal). Based on the existing cryocoolers onboard Akari (2006) and JEM/SMILES (2009), modifications for higher cooling power and reliability had been investigated. In the present development phase, the Engineering Models (EMs) of these upgraded cryocoolers are fabricated to carry out verification tests for cooling performance, mechanical performance and lifetime. Nominal cooling power of 200 mW at 20 K for the 2ST cooler and 40 mW at 4.5 K for the JT cooler were demonstrated with temperature and power margin. Mechanical performance test for the 2ST cooler units proves tolerability for pyro shock and vibration environment of the Astro-H criteria. Continuous running of the 4 K-class JT cooler combined with the 2ST precooler for lifetime test has achieved over 5000 h without any degradation of cooling performance. 相似文献
164.
Le Sech C Kobayashi K Usami N Furusawa Y Porcel E Lacombe S 《Nanotechnology》2012,23(7):078001; author reply 078002
A recent paper (Kim et al 2010 Nanotechnology 21 425102) presented results on the combination of irradiation by atomic ions of cells loaded by particles made of heavy atoms. They propose that the projectile induced x-rays emission (PIXE) mechanism has an important contribution to the enhancement of the cell death rate. Experiments made in our group to study the effects of such a combination have shown that the Auger effect induced in the high-Z atoms and the following induction of surrounding water radiolysis has an important contribution to the enhancement of the cell death rate. In the light of our studies we propose an alternative interpretation of the results presented in the paper by Kim et al. 相似文献
165.
Naoki Sugimoto Ryo Koike Noriko Furusho Makoto Tanno Chikako Yomota Kyoko Sato Takeshi Yamazaki Kenichi Tanamoto 《Food Additives & Contaminants》2007,24(8):799-806
Guidelines for the oxyethylene group (EO) content of polysorbates are set by the Food and Agriculture Organization/World Health Organization Joint Expert Committee on Food Additives. However, the classical titration method for EO determination is difficult and time-consuming. Here, we show that quantitative (1)H-nuclear magnetic resonance spectroscopy can determine the EO contents of polysorbates rapidly and simply. The EO signals were identified through comparisons with sorbitan monolaurate and poly(ethylene glycol) distearate. Potassium hydrogen phthalate was used as an internal standard. The EO contents were estimated from the ratio of the signal intensities of EO to the internal standard. Two nuclear magnetic resonance systems were used to validate the proposed method. The EO content of commercial polysorbates 20, 60, 65, and 80 was determined to be within the recommended limits using this technique. Our approach thus represents an additional or alternative method of determining the EO contents of polysorbates. 相似文献
166.
Naoko Ikuta Akira Tanaka Ayako Otsubo Noriko Ogawa Hiromitsu Yamamoto Tomoyuki Mizukami Shoji Arai Masayuki Okuno Keiji Terao Seiichi Matsugo 《International journal of molecular sciences》2014,15(11):20469-20485
α-Lipoic acid (ALA) has a chiral center at the C6 position, and exists as two enantiomers, R(+)-ALA (RALA) and S(−)-ALA (SALA). RALA is naturally occurring, and is a cofactor for mitochondrial enzymes, therefore playing a major role in energy metabolism. However, RALA cannot be used for pharmaceuticals or nutraceuticals because it readily polymerizes via a 1,2-dithiolane ring-opening when exposed to light or heat. So, it is highly desired to find out the method to stabilize RALA. The purpose of this study is to provide the spectroscopic information of stabilized RALA and SALA through complexation with cyclodextrins (CDs), α-CD, β-CD and γ-CD and to examine the physical characteristics of the resultant complexes in the solid state. The RALA-CD structures were elucidated based on the micro fourier transform infrared (FT-IR) and Raman analyses. The FT-IR results showed that the C=O stretching vibration of RALA appeared at 1717 cm−1 and then shifted on formation of the RALA-CD complexes. The Raman spectra showed that the S–S and C–S stretching vibrations for RALA at 511 cm−1 (S–S), 631 cm−1 (C–S) and 675 cm−1 (C–S) drastically weakened and almost disappeared upon complexation with CDs. Several peaks indicative of O–H vibrations also shifted or changed in intensity. These results indicate that RALA and CDs form host-guest complexes by interacting with one another. 相似文献
167.
Vikram Balasubramanian Youlin Li Tim Stotler Jeff Crompton Alfred Soboyejo Noriko Katsube Wol Soboyejo 《Materials and Manufacturing Processes》1999,14(6):845-860
This paper presents the results of a combined experimental and numerical study of continuous drive friction welding of 1045 steel. A new friction law is proposed for the estimation of the apparent coefficient of friction during direct to 3.36 m.s-1. The multiparameter friction equation can be incorporated in the numerical simulations to accurately predict the spatial temperature distributions in steels within the above parametric ranges. Regression equations could also be obtained for different material combinations using different sets of welding parameters. Further work is clearly needed to obtain empirical constants for other materials. 相似文献
168.
Fumihito Nishimura Noriko Watanabe Kikuaki Tanaka 《Computational Materials Science》1997,8(4):349-362
The uniaxial thermomechanical behavior in an Fe-based polycrystalline shape memory alloy is analyzed from the phenomenological point of view by means of the rate-type constitutive equation and the newly developed transformation kinetics. The forward and reverse transformations among the martensite phase produced in tension or in compression and the parent phase are shown to be depicted by the transformation zones bounded by the transformation start/finish lines on the stress-temperature plane. The shift of the lines, depending on the extent of prior transformation, is determined from the experimental data by the same authors. The stress-strain-temperature hysteresis loops and the recovery stress during heating are well simulated. 相似文献
169.
New preparation routes are applied to synthesize novel Cu/ZnO catalysts exhibiting high catalytic activity in methanol synthesis. In particular, the deposition–precipitation of copper onto high specific surface area (SSA) zinc oxide particles and the chemical vapor deposition of diethyl zinc turned out to be effective techniques, leading to promising methanol synthesis catalysts due to the enlargement of the Cu-ZnO interface. 相似文献
170.
The mechanism for CO or NO strong and weak chemisorptions on tungsten and platinum surfaces is discussed by the cluster model for metal surfaces on the basis of the local density functional scheme using the norm-conserving pseudo-potential in the linear combination of atomic orbitals method. Total energies, stretching frequencies and electronic structures of adsorbed CO and NO molecules obtained by the self-consistent calculations provide us with information to understand the experimental phenomena quantitatively. 相似文献