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排序方式: 共有1394条查询结果,搜索用时 390 毫秒
101.
Takeba K Fujinuma K Sakamoto M Jimbo K Oka H Ito Y Nakazawa H 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2003,44(5):246-252
A simple and rapid liquid chromatographic method was developed for the simultaneous determination of twelve benzimidazole anthelmintics in livestock foods using reversed-phase high-performance liquid chromatography with photodiode array detection (PDA). A sample was homogenized with acetonitrile and n-hexane, and centrifuged. The acetonitrile phase was isolated and evaporated. The residue was dissolved in 0.1 mol/L carbonate buffer solution (pH = 9.1), sonicated, and then subjected to clean-up on a Bond Elut LRC-C18 cartridge. The benzimidazole compounds were separated isocratically on a Capcell Pak C18 UG 120 (5 microns, 150 x 4.6 mm i.d.) column and detected by PDA at 295 and 313 nm. Mixtures of acetonitrile and 0.05 mol/L ammonium acetate in mixing ratios of (20:80) and (40:60) were used as the mobile phase, and the flow-rate was 1.0 mL/min at 40 degrees C. The mean recoveries (n = 3) from 0.1-0.5 microgram/g added samples were 72.6-97.2% with coefficients of variation of 0.3-8.5%. The detection limits were 0.01-0.05 microgram/g. 相似文献
102.
A novel anionic surfactant templating route for synthesizing mesoporous silica with unique structure
Che S Garcia-Bennett AE Yokoi T Sakamoto K Kunieda H Terasaki O Tatsumi T 《Nature materials》2003,2(12):801-805
Anionic surfactants are used in greater volume than any other surfactants because of their highly potent detergency and low cost of manufacture. However, they have not been used as templates for synthesizing mesoporous silica. Here we show a templating route for preparing mesoporous silicas based on self-assembly of anionic surfactants and inorganic precursors. We use aminosilane or quaternized aminosilane as co-structure-directing agent (CSDA), which is different from previous pathways. The alkoxysilane site of CSDA is co-condensed with inorganic precursors; the ammonium site of CSDA, attached to silicon atoms incorporated into the wall, electrostatically interacts with the anionic surfactants to produce well-ordered anionic-surfactant-templated mesoporous silicas (AMS). These have new structures with periodic modulations as well as two-dimensional hexagonal and lamellar phases. The periodic modulations may be caused by the coexistence of micelles that differ in size or curvature, possibly owing to local chirality. These mesoporous silicas provide a new family of mesoporous materials as well as shedding light on the structural behaviour of anionic surfactants. 相似文献
103.
The solid-solution compounds of Gd4(Al1 – x
Ga
x
)2O9 (x = 0.0–1.0) were prepared at 1600°C for 5 h in air. The unit cell volume of the compounds increased from 0.853 to 0.878 nm3 with x. Phase transitions having a temperature hysteresis were observed from 1100° to 1400°C by calorimetry and dilatometry. The transition temperature increased with x. The volume of the high-temperature phase was 0.5% smaller than that of the low-temperature phase at the transition temperature. The volume changes were independent of x. The hysteresis width observed by the dilatometry was about 300°C for the Gd4Al2O9 ceramics (grain size: about 1 m) and decreased to 50°C for the Gd4(Al0.2Ga0.8)2O9 ceramics (grain size: over 10 m). Gd4Ga2O9 was unstable at low temperature and decomposed to Gd3GaO6 and Gd3Ga5O12 during the thermal analyses. 相似文献
104.
Endo A Yamaguchi Y Sakamoto Y Yoshizawa M Tsuda S 《Radiation protection dosimetry》2001,93(3):207-214
On 30 September 1999, a criticality accident occurred at a uranium processing plant operated by JCO in Tokai-mura, Japan and the criticality remained for about 20 h. Almost all doses to the neighbouring residents were brought by neutrons and gamma rays emitted from the facility rather than fission products released to the environment. External doses in the environment were evaluated using radiation monitoring data and radiation transport calculation. A pattern of the dose rate evolution was modelled based on the records of gamma ray monitors in the JCO facilities. Relations between the ambient dose equivalent rates of neutrons/gamma rays and the distance from the facility were determined from the monitoring data obtained around the accident site. Conversion from the ambient dose equivalent to the effective dose equivalent was made assuming the energy spectra calculated by the radiation transport code, ANISN. It was estimated that the people who stayed outside the 350 m zone would receive doses of less than 1 mSv. 相似文献
105.
Daikoku M. Morita I. Taga H. Tanaka H. Kawanishi T. Sakamoto T. Miyazaki T. Fujita T. 《Lightwave Technology, Journal of》2007,25(1):139-145
In order to realize a future 100-Gb Ethernet (100 GbE) transport, 100-Gb/s transmission without 100-GHz-class electronics and optical time-division-multiplexing technique was demonstrated. By using a differential quadrature phase-shift-keying (DQPSK) modulation format and commercially available electronics, 2- and 50-km transmissions of 100-Gb/s signal were successfully achieved over a standard single mode fiber. The receiver sensitivity, chromatic dispersion, and differential group delay tolerances of 100-Gb/s DQPSK signal were also evaluated. Through these evaluations, the possibility of DQPSK modulation for future 100-GbE transport is verified 相似文献
106.
Wavelength-tunable ultra-flat optical frequency comb generation is demonstrated using only a conventional Mach-Zehnder modulator that is asymmetrically dual-driven by large-amplitude sinusoidal signals with different amplitudes. A 10 GHz-spaced frequency comb with a 10 dB bandwidth of 230 GHz was experimentally generated. In addition, 50 nm widely wavelength tunable operation was achieved. 相似文献
107.
Naonori Sakamoto Shunji Araki Masahiro Yoshimura 《Journal of the American Ceramic Society》2009,92(S1):S157-S161
Eutectic melt solidification is shown to avoid cracking during solidification by quenching an amorphous phase. Subsequent annealing results in micro/nanostructure ceramics. This strategy has been applied to HfO2 –Al2 O3 –GdAlO3 and Y2 O3 –CaO–Al2 O3 ternary systems that have deep eutectics. In most cases, ceramic materials cracks when they are solidified from melt due to the thermal stress accumulated on the grain boundaries, the large specific volume difference between the melt and the crystalline solid, etc. The main reason why this strategy works is that a eutectic composition yields an amorphous phase from the melts by rapid cooling and the amorphous phase enables to design crystallization without cracking by postannealing. Appropriate postannealing for the quenched amorphous enables to control the crystallization behavior from the amorphous phase, which yields nanostructured composites without cracking. For the HfO2 –Al2 O3 –GdAlO3 case, the melt solidification and postannealing yields a nanocomposite with high transparency due to reduced scattering of 5–10 nm crystallites. For the Y2 O3 –CaO–Al2 O3 case, a plate-shaped bulk composite is obtained without cracking by molding the melt and postannealing. 相似文献
108.
Sakamoto M. Cardinal M.R. Endriz J.G. Welch D.F. Scifres D.R. 《Electronics letters》1990,26(7):422-424
One cm wide monolithic laser diode arrays emitting around 810 nm with a 2 mm total aperture width have been characterised under CW conditions. CW operation up to 16 W has been achieved at a heatsink temperature of 70 degrees C. Several arrays have been lifetested at 10 W CW at a 20 degrees C heatsink temperature for a few thousand hours and have projected lifetimes of between 5000 and 17000 hours. The temperature dependence of the degradation rate was characterised, from which data an activation energy of 0.2 eV was obtained.<> 相似文献
109.
Satoshi Miyaguchi Shinichi Ishizuka Takeo Wakimoto Jun Funaki Yoshinori Fukuda Hirofumi Kubota Kenji Yoshida Teruichi Watanabe Hideo Ochi Tsuyoshi Sakamoto Masami Tsuchida Isamu Ohshita Teruo Tohma 《Journal of the Society for Information Display》1999,7(3):221-226
Abstract— A full-color 5.2-inch 1/4-VGA passive-matrix organic LED display has been developed, adopting selective deposition for the different emitting materials. The display features 320 (×3) × 240 pixels with an equivalent pixel size of 0.33 × 0.33 mm, white peak luminance of over 150 cd/m2, and power consumption of 6 W. 相似文献
110.
Hemophilia B is caused by a deficit or decreased activity of factor IX. Mutation in factor IX is made up of a majority of
amino acid substitutions. We examined the relation between the activation level of factor IX and the category of amino acid
substitution with regression analysis. As parameters, we used four physical-chemical parameters of amino acids and Dayhoff’s
PAM matrix. In addition, the average of the activation level with the same amino acid substitution was used for the analysis.
We analyzed the relationship between variations containing cysteine or factor IX’s seven regions and activity levels.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献