In this study, programmed temperature vaporization in the solvent vent mode (PTV-SV) of gas chromatography-mass spectrometry was optimized and validated for the analysis of particle-phase and gas-phase polycyclic aromatic hydrocarbons from diesel engine combustion. Because of the large number of experimental and response variables to be studied, central composite inscribed design was used to optimize the PTV-SV injection factors, including initial inlet temperature, vaporization flow and time. The optimized PTV-SV method was validated by linearity, accuracy and sensitivity. For the 16 Polycyclic aromatic hydrocarbons (PAHs) studied, the correlation coefficients for the calibration plots of peak areas versus concentrations (0.5–300 ng mL⁻¹) ranged from 0.9812–0.9998. Limits of detection ranged from 0.016–20,130.375 ng mL⁻¹, and limits of quantification ranged from 0.055–1.25 ng mL⁻¹. The optimized method was used for the analysis of real samples collected from a diesel engine, which included particle-phase and gas-phase PAHs. The results showed that the improved PTV-SV method was satisfying for simultaneously identifying and quantifying PAHs produced during diesel combustion.

A 2998MHz, 60MW klystron has been developed for future linear accelerators of synchrotron radiation sources. In order to save development and construction time, the 2998MHz, 60MW klystron is a modified version of an existing 2856MHz klystron used in linear accelerator of Beijing Electron-Positron Collider II. Based on the simulations, it was shown that the scaled version klystron was able to produce more than 60MW at a 350kV beam voltage. A prototype was built and tested. It successfully produced 50MW output power with an RF pulse width of 4.0ms, which exceeded the operating requirement of China's High Energy Photon Source. It also produced 62MW with an RF pulse width of 1.6ms, which proved the validity of new RF circuit design. This paper describes the details of the progresses of this klystron and advantages of this tube development.