Comparative analyses of complete chloroplast genomes reveal interspecific difference and intraspecific variation of Tripterygium genus.

The genus Tripterygium was of great medicinal value and attracted much attention on the taxonomic study using morphological and molecular methods. In this study, we assembled 12 chloroplast genomes of Tripterygium to reveal interspecific difference and intraspecific variation. The sequence length (156,692-157,061 bp) and structure of Tripterygium were conserved. Comparative analyses presented abundant variable regions for further study. Meanwhile, we determined the ndhB gene under positive selection through adaptive evolution analysis. And the phylogenetic analyses based on 15 chloroplast genomes supported the monophyly of Tripterygium hypoglaucum and the potential sister relationship between Tripterygium wilfordii and Tripterygium regelii. Molecular dating analysis indicated that the divergence time within Tripterygium was approximately 5.99 Ma (95% HPD = 3.11-8.68 Ma). The results in our study provided new insights into the taxonomy, evolution process, and phylogenetic construction of Tripterygium using complete plastid genomes.

[Spectral response measurement of FUV image intensifier].

It is possible to obtain some space weather parameters such as the electron flux and mean energy of the precipitating electrons from the far ultraviolet (FUV) radiance of the aurora observed in a nadir viewing geometry, and the FUV image intensifier is one of the key equipment that used for observation the FUV radiance of the aurora in a nadir viewing geometry. The capability of this equipment will affect the whole purpose of the detection. And the responsibility to the wavelength is the most important parameter of image intensifier. Using the VUV beamline f rom synchrotron radiation as optical source, with PMT and Si-photodiode to detect the optical signal from synchrotron radiation and image intensifier separately, the authors measured the relatively spectral response distribution of our FUV image intensifier from 135 to 250 nm. The measurement result shows that the equipment can work well between 140 and 190 nm and the peak response is near 160 nm, and it can be used for our FUV aurora camera.

[The study of aluminium diffuser calibration in the UV].

A bi-directional reflectance distribution function (BRDF) measurement setup in the ultraviolet spectral range was established. The BRDF of the aluminium diffusers at a given orientation was measured. The relative accuracy of the BRDF measurement is better than 2.5%. The hemispheric reflectance of the aluminium diffusers was measured in the wavelength range from 250 to 650 nm. It increases with the wavelength, and changes about 6% from 300 to 360 nm. It decreases with the time. Since the diffuser was made (about one year ago), from 250 to 300 nm, the peak decrease in the hemispheric reflectance can reach 2.6%, and the average decrease is 1.5%. From 300 to 360 nm, it has an average decrease of 0.9% decrease, and 0.8% when wavelength is longer than 360 nm.