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The mechanical properties and microstructure of tested steel strengthened via Al at different solution and aging temperatures were studied by mechanical property test, optical microscope and transmission electron microscope. The results show that the tensile strength and yield strength of tested steel reach up to 1876MPa and 1762MPa respectively, with the higher strength and better match of toughness. Fine lath martensite with high-density dislocations is formed after solution and the precipitation of dispersive NiAl phase from matrix makes the strength greatly improved during the aging. The strength of tested steel decreases rapidly after reaching peak due to the coarsening of particles, namely, overaging phenomenon occurs. The optimum comprehensive mechanical properties of tested steel can be obtained after solution treatment at 820℃, cold treatment at -70℃ and aging treatment at 540℃.

Cannabaceae are a relatively small family of angiosperms, but they include several species of huge economic and cultural significance: marijuana or hemp (Cannabis sativa) and hops (Humulus lupulus). Previous phylogenetic studies have clarified the most deep relationships in Cannabaceae, but relationships remain ambiguous among several major lineages. Here, we sampled 82 species representing all genera of Cannabaceae and utilized a new dataset of 90 nuclear genes and 82 chloroplast loci from Hyb‐Seq to investigate the phylogenomics of Cannabaceae. Nuclear phylogenetic analyses revealed a robust and consistent backbone for Cannabaceae. We observed nuclear gene‐tree conflict at several deep nodes in inferred species trees, also cyto‐nuclear discordance concerning the relationship between Gironniera and Lozanella and the relationships among Trema s.l. (including Parasponia), Cannabis + Humulus, and Chaetachme + Pteroceltis. Coalescent simulations and network analyses suggest that observed deep cyto‐nuclear discordances were most likely to stem from incomplete lineage sorting (ILS); nuclear gene‐tree conflict might be caused by both ILS and gene flow between species. All genera of Cannabaceae were recovered as monophyletic, except for Celtis, which consisted of two distinct clades: Celtis I (including most Celtis species) and Celtis II (including Celtis gomphophylla and Celtis schippii). We suggest that Celtis II should be recognized as the independent genus Sparrea based on both molecular and morphological evidence. Our work provides the most comprehensive and reliable phylogeny to date for Cannabaceae, enabling further exploration of evolutionary patterns across this family and highlighting the necessity of comparing nuclear with chloroplast data to examine the evolutionary history of plant groups. [ABSTRACT FROM AUTHOR]

Dispersal scenarios have been favored over tectonic vicariance as an explanation for disjunct distributions in many plant taxa during the last two decades. However, this argument has been insufficiently addressed in cosmopolitan groups showing disjunct patterns in both the temperate and tropical regions. In this study, we used the Cannabaceae, an angiosperm family distributed in tropical and temperate regions of both the New World and the Old World, to explore the role of dispersal in shaping disjunct patterns and species diversification of cosmopolitan plants. We reconstructed the phylogenetic relationships of all 10 genera and 75 species of Cannabaceae (ca. 64.1% of recognized species) based on eight DNA regions. Based on fossil calibrations, we estimated the divergence times and net diversification rates. We further inferred the ancestral geographical ranges with several models and compared the fitness of different models. The Cannabaceae and most genera were strongly supported as monophyletic except for the Parasponia being embedded within the Trema. The Celtis were resolved into two strongly supported clades primarily corresponding to temperate and tropical regions. We inferred that the Cannabaceae originated at ca. 93 Ma, and that subsequent rampant and widespread dispersals shaped the intercontinentally disjunct distribution of the Cannabaceae. Dispersal coincides with adaptation to drier and colder climate in the Northern Hemisphere, or humid and warm climate in the tropical regions, followed by rapid species diversification. This study advances our understanding as to the formation of distribution patterns and species diversification of a plant family with tropical to temperate disjunct distributions. [ABSTRACT FROM AUTHOR]

Abstract The family Lauraceae is a major component of tropical and subtropical forests worldwide, and includes some commercially important timber trees and medicinal plants. However, phylogenetic relationships within Lauraceae have long been problematic due to low sequence divergence in commonly used markers, even between morphologically distinct taxa within the family. Here we present phylogenetic analyses of 43 newly generated Lauraceae plastomes together with 77 plastomes obtained from GenBank, representing 24 genera of Lauraceae and 17 related families of angiosperms, plus nine barcodes from 19 additional species in 18 genera of Lauraceae, in order to reconstruct highly supported relationships for the Lauraceae. Our phylogeny supports the relationships: sisterhood of the Lauraceae and a clade containing Hernandiaceae and Monimiaceae, with Atherospermataceae and Gomortegaceae being the next sister groups, followed by Calycanthaceae. Our results highlight a monophyletic Lauraceae, with nine well‐supported clades as follows: Hypodaphnis clade, Beilschmiedia–Cryptocarya clade, Cassytha clade, Neocinnamomum clade, Caryodaphnopsis clade, Chlorocardium–Mezilaurus clade, Machilus–Persea clade, Cinnamomum–Ocotea clade, and Laurus–Neolitsea clade. The topology recovered here is consistent with the patterns of plastome structural evolution and morphological synapomorphies reported previously. More specifically, flower sex, living type, inflorescence type, ovary position, anther locus number, leaf arrangement, leaf venation, lateral vein number, tree height, and inflorescence location all represent morphological synapomorphies of different lineages. Our findings have taxonomic implications and two new tribes, Caryodaphnopsideae and Neocinnamomeae, are described, and the composition of four other tribes is updated. The phylogeny recovered here provides a robust phylogenetic framework through which to address the evolutionary history of the Magnoliids, the third‐largest group of Mesangiospermae. [ABSTRACT FROM AUTHOR]