Endiandramacrocarpa (Lauraceae), a new tree species from south-western China.

Endiandramacrocarpa, a new species of Endiandra (Lauraceae) from Yunnan Province of south-western China, is here described and illustrated, based on morphological evidence. Compared to other Endiandra species occurring in south China and the adjacent regions in Indochina, this species is mainly characterised by its much larger ellipsoidal fruits (up to 11 × 6 cm), as well as glabrous branchlets and puberulent inflorescences.

Experimental and Computational Studies on Octyl Hydroxamic Acid as an Environmentally Friendly Inhibitor of Cobalt Chemical Mechanical Polishing.

Octyl hydroxamic acid (OHA) was investigated as an inhibitor in H2O2-based alkaline silica dispersions for the polishing of cobalt (Co) films for interconnect applications. A combination of experiments and density functional theory (DFT) was used to investigate the inhibition effect and the mechanism of OHA on the Co surface. On the basis of the experiments, it can be proven that OHA has an inhibition effect on Co, which came from the inhibition of the cathodic reaction. The X-ray photoelectron spectroscopy (XPS) experiments show that the adsorption of OHA weakened the oxidation of the Co surface and protected the Co surface from corrosion. On the basis of the calculations, it can be proven that the OHAketone (ion) is most likely to react with the Co surface, and it can adsorb on the Co surface by Co-O bonds. This study provides important microscopic insights for understanding the corrosion protection of Co interconnect metals and helps to explain the corrosion inhibition mechanism of the organic-metal interface during the CMP process.

Opening a door to the spatiotemporal history of plants from the tropical Indochina Peninsula to subtropical China.

The complexity of global biodiversity in the tropical Indochina Peninsula and subtropical China bioregions has fascinated biologists for decades, but little is known about the spatiotemporal patterns in these regions. Accordingly, the aims of present study were to investigate the evolutionary and distribution patterns of Engelhardia in these regions and establish a model for examining biogeographic patterns and geological events throughout the tropical Indochina Peninsula and subtropical China. The effects of geological events occurring in the area between the Indochina Peninsula and subtropical China bioregions on the two trees species (i.e., E. roxburghiana and E. fenzelii) were evaluated. A robust phylogenetic framework of 884 individuals from 79 populations was used to generate time-calibrated cytoplasmic and nuclear phylogenetic frameworks based on cpDNA, nrDNA, and nSSR data, respectively. When considered along with ancestral area reconstructions, the genetic data were also used to assess and reconstruct the species' population genetic structure and diversity. These analyses yielded important information about the (1) historical distribution relationships between the tropical and subtropical flora of China; (2) effects of the East Asian summer monsoon (EASM) on the evolutionary history of Asia's plants; and (3) importance of biogeography in conservation planning. Although cytoplasmic-nuclear discordance indicated cpDNA and nrDNA were subject to distinct evolutionary mechanisms that reflected respective evolutionary histories of the plastid and nuclear genomes of prior demographic and biogeographic events. The tropical elements of Engelhardia occupied the Indochina Peninsula during the early Eocene, whereas the subtropical elements were transformed from the tropical elements during Miocene cooling and the onset of the EASM at the Oligocene-Miocene boundary, intensified during the late Miocene and Pliocene, facilitating the transformation of Engelhardia from the tropical Indochina Peninsula to subtropical China. Demographic history provided insights into prominent planning frameworks in conservation biology, namely that subtropical China functioned as a refugium during past climate oscillations and will continue to serve in this capacity in the future.

Shining a light on species delimitation in the tree genus Engelhardia Leschenault ex Blume (Juglandaceae).

Enhanced efficacy in species delimitation is critically important in biology given the pending biodiversity crisis under global warming and anthropogenic activity. In particular, delineation of traditional classifications in view of the complexity of species requires an integrative approach to effectively define species boundaries, and this is a major focus of systematic biology. Here, we explored species delimitation of Engelhardia in tropical and subtropical Asia. In total, 716 individuals in 71 populations were genotyped using five chloroplast regions, one nuclear DNA region (nrITS), and 11 nuclear simple sequence repeats (nSSR). Phylogenetic trees were constructed and relationships among species were assessed. Molecular analyses were then combined with 14 morphological characteristics of 720 specimens to further explore the species boundaries of Engelhardia. Integrating phylogenetic and morphological clusters provided well-resolved relationships to delineate seven species. The results suggested that: first, that E. fenzelii, E. roxburghiana, E. hainanensis, E. apoensis, and E. serrata are distinct species; second, E. spicata var. spicata, E. spicata var. aceriflora, E. spicata var. colebrookeana, and E. rigida should be combined under E. spicata and treated as a species complex; third, E. serrata var. cambodica should be raised to species level and named E. villosa. We illuminated that bias thresholds determining the cluster number for delimiting species boundaries were substantially reduced when morphological data were incorporated. Our results urge caution when using the concepts of subspecies and varieties in order to prevent confusion, particularly with respect to species delimitation for tropical and subtropical species. In some cases, re-ranking or combining subspecies and/or varieties may enable more accurate species delimitation.