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991.
In order to establish a new method for simultaneous determination of sulfated bile acids without deconjugation, separation
of 3-sulfates of unconjugated, glyco- and tauroconjugated bile acids by high-performance liquid chromatography has been undertaken.
The preliminary experiment indicated that reversed phase chromatography on an ODS SC-02 column using ammonium carbonate aqueous
solution/acetonitrile as a mobile phase would be promising. The ratio of peak width to retention time was varied depending
upon the salt concentration. The content of water in mobile phase exerted an influence on the capacity ratio to a certain
extent, but not on the resolution. The use of 0.5% ammonium carbonate/acetonitrile (26∶8 and 20∶8, v/v) was found to be suitable
for complete resolution of sulfated cholate, chenodeoxycholate, deoxycholate, lithocholate and their glyco- and tauro-conjugates. 相似文献
992.
Susa Nobuhiko Kanbe H?ros?h? Nishioka Takashi Ohmachi Yoshiro 《Electronics letters》1979,15(17):535-537
A GaAs avalanche photodiode with a multiplication factor as high as 8000 was prepared by Zn diffusion and proton double implantation. The proton-implanted guard ring completely prevented edge breakdown, and multiplication occurred uniformly over the junction area. Dark current was proved to be due to a leakage current at the periphery between junction and implanted layer. 相似文献
993.
994.
995.
Polyacrylic chloride was reacted with aminonaphthol sulfonic acid to give a polymeric intermediate, from which the corresponding dyestuff was prepared by coupling with an aromatic diazonium salt. The water-solubility of the polymeric azo dye was found to depend mainly on the number of sulfonic groups in the molecular chain, and the colouring of dye was comparatively rich in variety. A copolymer of acrylic chloride with methyl methacrylate was directly reacted with a dyestuff containing amino groups to give a polymeric dye. In the molecular chain of those polymeric dyes, the functional structure of the dyestuff was kept by its incorporation to the acrylic polymer chain. 相似文献
996.
997.
998.
Katsuo Ikeda Takashi Yamamura Yasumasa Mitamura Shiokazu Fujiwara Yoshiharu Tominaga Takeshi Kiyono 《Pattern recognition》1981,13(3):191-206
An on-line recognition method for hand-written characters utilizing stroke vector sequences and a positional vector sequence has been developed. The number of target characters is about 2000, and fairly good recognition scores have been attained. Our scheme uses the number of strokes as the primary parameter. We employ three types of recognition strategy depending on the number of strokes. The general stroke vector sequence method, devised to analyze the shape, can represent both skeleton and local characteristics by a small amount of information; and the restricted dynamic programming method is effective to determine the shape of a stroke. The similarity of two shapes and the complexity of a stroke have been introduced to reduce the dictionary size and the processing time, respectively. 相似文献
999.
The occurrence and determination of a herbicide, benthiocarb, 4-chlorobenzyl N,N-diethylthiolcarbamate (Saturn®) in rivers and agricultural drainages was investigated. Benthiocarb residues were detected in water samples when it has been applied to rice paddies, after rice seedling transplantation, in concentrations of between 10.00 and 0.11 μg/l. These residues entered into rivers and agricultural drainages as a result of overflows from rice paddies. However, benthiocarb residues could not be found in water samples after the termination of its application to rice paddies, suggesting that the applied benthiocarb might be degraded by microbial and physico-chemical actions such as photochemical reactions occurring on the soil surface. Benthiocarb residue levels were higher in longer rivers than in agricultural drainage. The contribution of rainfall to the benthiocarb concentrations was shown. Benthiocarb in water was extracted with n-hexane and identified by a gas chromatography using a flame photometric detector (sulphur filter 394 nm) and a combined gas chromatography-mass spectrometry-computer system. The minimum detectable amount of benthiocarb in water sample by gas chromatography was 0.56 ng and about 100 ng of benthiocarb could be identified by a gas chromatography-mass spectrometry-computer system. 相似文献
1000.
The compressive, flexural, torsional and dynamic torsional strengths of polycrystalline hydroxyapatite sintered at a temperature of 1300° C for 3 h were found to be 509, 113, 76 and 68 MPa, respectively. The mechanical properties of polycrystalline hydroxyapatite are compared with those of cortical bone, dentine and enamel. SEM observation of the fracture surfaces indicates a predomination of transgranular failures. 相似文献