[Identification of Chemical Constituents of the Leaves from Acanthopanax senticosus by UPLC-Q-TOF-MS/MS].

Objective: To analyze the chemical compositions of the leaves from Acanthopanax senticosus. Methods: Rapid identification of chemical constituents in the leaves of Acanthopanax senticosus by UPLC-Q-TOF-MS / MS. The chemical constituents were identified and speculated by using Peakview data processing software, the retention time, exact relative molecular mass, and cleavage fragments of MS / MS were detected. Chromatography-mass spectrometry conditions were as follows, the analysis was performed on Waters BEH C18column( 100 mm × 2. 1 mm,1. 7 µm) in gradient elution with a mobile phase of 0. 1% formic acid aqueous solution and 0. 1%formic acid acetonitrile, the flow rate was at 0. 3 m L / min, the data was collected by the negative and positive ion mode using ESI ion source. Results: 30 compounds were identified and speculated by the standards and compounds of MS / MS, the references and Chemispider database. Conclusion: This method is fast, sensitive and comprehensive with the rapid identification of chemical constituents in the leaves of Acanthopanax senticosus, which will provide the evidences for perfecting the quality standard, and clarify the efficacy material base of the leaves of Acanthopanax senticosus.

[Photoemission characteristic of transmission-mode extended blue GaAs photocathodes].

Based on the theoretical models of computing the photocathode optical performance, quantum yield and integral sensitivity, the photoemission characteristics of the domestic and ITT's transmission-mode extended blue GaAs photocathodes, namely the cathode optical properties and performance parameters, were respectively investigated. The compared results show that the integral sensitivity of the domestic transmission-mode extended blue photocathode has achieved 2,100 microA x lm(-1), still falling behind the ITT's integral sensitivity of 2,750 µA x m(-1). The reasons for the difference in quantum yield curves are that, on one hand, the thickness of GaAlAs window-layer and the Al mole fraction play a critical role in the short-wavelength response, especially in the extended blue region. On the other hand, the cathode performance parameters such as electron diffusion length and back interface recombination velocity work on the long-wavelength and short-wavelength response. All these factors are subject to the backwardness of basic industrial manufacturing level.