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A liquid chromatography-mass spectrometry method was developed for the simultaneous quantitation of (2R,3R)-Dihydromyricetin and Myricetin in rat plasma samples to facilitate analysis of samples collected after administration of SenDeng-4 medicine. The plasma was subjected to protein precipitation with HCl (containing 10% ascorbic acid) and analyzed using electrospray ionization mass spectrometry in selected ion monitoring mode with Paeoniflorin as an internal standard. Good linearity for the two compounds was observed. The intra- and inter-day precision of analysis was, Author(s): Pu Bai [sup.1] [sup.2] [sup.3], Xin Jia [sup.1] [sup.2] [sup.4], Yu Dong [sup.1] [sup.2], Chula Sa [sup.1], Guoyuan Sun [sup.2] [sup.5], Xiaoling Zhu [sup.2] [sup.5] Author Affiliations: (1) grid.410612.0, [...]

The spheroidization behavior of the dendritic b.c.c. phase dispersed in a bulk metallic glass (BMG) matrix was investigated through applying semi-solid isothermal processing and a subsequent rapid quenching procedure to a Zr-based モ-phase composite. The Zr-based composite with the composition of Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5 was prefabricated by a water-cooled copper mold-casting method and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that the composite consists of a glassy matrix and uniformly distributed fine dendrites of the モ-Zr solid solution with the body-centered-cubic (b.c.c.) structure. Based on the differential scanning calorimeter (DSC) examination results, and in view of the b.c.c. モ-Zr to h.c.p. メ-Zr phase transition temperature, a semi-solid holding temperature of 900 ìC was determined. After reheating the prefabricated composite to the semi-solid temperature, followed by an isothermal holding process at this temperature for 5 min, and then quenching the semi-solid mixture into iced-water; the two-phase microstructure composed of a BMG matrix and uniformly dispersed spherical b.c.c. モ-Zr particles with a high degree of sphericity was achieved. The present spheroidization transition is a thermodynamically autonomic behavior, and essentially a diffusion process controlled by kinetic factors; and the formation of the BMG matrix should be attributed to the rapid quenching of the semi-solid mixture as well as the large glass-forming ability of the remaining melt in the semi-solid mixture.

The spheroidization behavior of the dendritic b.c.c. phase dispersed in a bulk metallic glass (BMG) matrix was investigated through applying semi-solid isothermal processing and a subsequent rapid quenching procedure to a Zr-based β-phase composite. The Zr-based composite with the composition of Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6 Be12.5 was prefabricated by a water-cooled copper mold-casting method and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that the composite consists of a glassy matrix and uniformly distributed fine dendrites of the β-Zr solid solution with the body-centered-cubic (b.c.c.) structure. Based on the differential scanning calorimeter (DSC) examination results, and in view of the b.c.c. β-Zr to h.c.p. α-Zr phase transition temperature, a semi-solid holding temperature of 900 ºC was determined. After reheating the prefabricated composite to the semi-solid temperature, followed by an isothermal holding process at this temperature for 5 min, and then quenching the semi-solid mixture into iced-water; the two-phase microstructure composed of a BMG matrix and uniformly dispersed spherical b.c.c. β-Zr particles with a high degree of sphericity was achieved. The present spheroidization transition is a thermodynamically autonomic behavior, and essentially a diffusion process controlled by kinetic factors; and the formation of the BMG matrix should be attributed to the rapid quenching of the semi-solid mixture as well as the large glass-forming ability of the remaining melt in the semi-solid mixture. [ABSTRACT FROM AUTHOR]