Phylogenetic origin of Beckmannia (Poaceae) inferred from molecular evidence

The phylogenetic origin of Beckmannia remains unknown. The genus has been placed within the Chlorideae, Aveneae （Agrostideae）, Poeae, or treated as an isolate lineage, Beckmanniinae. In the present study, we used nuclear internal transcribed spacer （ITS） and chloroplast trnL-F sequences to examine the phylogenetic relationship between Beckmannia and those genera that have assumed to be related. On the basis of the results of our studies, the following conclusions could be drawn： （i） Beckmannia and Alopecurus are sister groups with high support; and （ii） Beckmannia and Alopecurus are nested in the Poeae clade with high support. The results of our analysis suggest that Beckmannia should be placed in Poeae.

Recent Advances in Carbon-Based Adsorbents for Adsorptive Separation of Light Hydrocarbons

Light hydrocarbons(LHs)separation is an important process in petrochemical industry.The current separation technology predominantly relies on cryogenic distillation,which results in considerable energy consumption.Adsorptive separation using porous solids has received widespread attention due to its lower energy footprint and higher efficiency.Thus,tremendous efforts have been devoted to the design and synthesis of high-performance porous solids.Among them,porous carbons display exceptional stability,tunable pore structure,and surface chemistry and thus represent a class of novel adsorbents upon achieving the matched pore structures for LHs separations.In this review,the modulation strategies toward advanced carbonbased adsorbents for LHs separation are firstly reviewed.Then,the relationships between separation performances and key structural parameters of carbon adsorbents are discussed by exemplifying specific separation cases.The research findings on the control of the pore structures as well as the quantification of the adsorption sites are highlighted.Finally,the challenges of carbonaceous adsorbents facing for LHs separation are given,which would motivate us to rationally design more efficient absorbents and separation processes in future.

Grazing incidence polarized light imaging of footwear prints

Footwear prints are important evidence in criminal investigation. They represent changes in the surface morphology due to disturbance to fine particle distributions. Existing non-contact optical detection methods usually measure the light intensity contrasts between the footwear prints and the ground, which can be enhanced by grazing incident illumination. We take polari-zation images of footwear prints on different types of floors using a commercial single lens reflex color camera. Results show that adding linear polarizers in front of the camera lens and light source improves the contrast of footwear print images. The best contrasts are achieved in degree of linear polarization. In addition, the three-color channels of the camera can be used to examine the spectral features of the polarization images. According to the experimental results, the best contrast is obtained at the blue channel. The current work shows that grazing incidence polarized light imaging can effectively enhance the contrast of the footwear prints against the floors, which would help obtain footwear evidence in criminal investigation.