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Evergreen sclerophyllous oak forests (ESOFs) in southwestern China are a special vegetation type developed in response to the expansion of arid habitats after the uplift of the Himalayas. Here, we used chloroplast (cp) DNA and nuclear ribosomal (nr) DNA to investigate the fine-scale genetic variation patterns of six sympatric oaks (Quercus, Fagaceae) in the hot-dry valley ESOFs of the Jinsha River, southwestern China. Three cp genomes were assembled for each species. Nine cp genome haplotypes and 16 nrDNA haplotypes were identified based on single-nucleotide variants and indels. Our results demonstrated that discordance existed between the cpDNA and nrDNA phylogenies of the sclerophyllous oaks in section Ilex. The nrDNA phylogeny was consistent with species boundaries, while the cpDNA phylogeny was decoupled from taxonomy. Interspecific sharing of closely related cp genome haplotypes was detected between Quercus cocciferoides and the other two sclerophyllous oaks, Q. longispica and Q. franchetii. Specifically, Q. cocciferoides and Q. longispica sampled in a mixed stand exhibited two haplotypes that differed by a 9 bp indel. The local distribution of the two highly similar haplotypes suggested that they may have arisen from ancient introgression. Given that the two species have diverged for a long time, it is possible that the ancestral cp genome of one species was captured by another species through asymmetric introgression in early times, and an indel event occurred subsequently. Phylogenetic analyses using more previously published cp genome sequences indicated that Q. cocciferoides and Q. franchetii shared multiple cpDNA lineages of Ilex oaks, which may be caused by shared ancestral polymorphism and/or ancient introgression. Our study showed that at least three highly variable regions (ψycf1, ndhF-rpl32, and trnKUUU-rps16 or rpl32-trnLUAG) can distinguish the nine haplotypes identified by whole-cp genome sequences. These markers are useful for the evolutionary studies of the maternal lineages of oaks in hot-dry valley ESOFs. [ABSTRACT FROM AUTHOR]

The pollution and scarcity of freshwater resources are global problems that have a significant influence on human life. It is very important to remove harmful substances in the water to realize the recycling of water resources. Hydrogels have recently attracted attention due to their special three-dimensional network structure, large surface area, and pores, which show great potential for the removal of pollutants in water. In their preparation, natural polymers are one of the preferred materials because of their wide availability, low cost, and easy thermal degradation. However, when it is directly used for adsorption, its performance is unsatisfactory, so it usually needs to be modified in the preparation process. This paper reviews the modification and adsorption properties of polysaccharide-based natural polymer hydrogels, such as cellulose, chitosan, starch, and sodium alginate, and discusses the effects of their types and structures on performance and recent technological advances. [ABSTRACT FROM AUTHOR]

A high-gain and wideband interconnected magneto-electric (ME) dipole on a single-layer PCB substrate is designed for 5G communication applications. Microstrip lines and coplanar striplines (CPSs) serve as transmission lines to connect the ME dipole elements along the E-plane and the H-plane directions, respectively. Impedance matching and sidelobe-level suppression are the key challenges to design a large-scale interconnected ME dipole antenna array. It is shown that impedance matching can be improved by introducing slots and adjusting the width of microstrip lines. Sidelobe level can be enhanced by properly choosing the length of the microstrip lines. A 5 × 5 interconnected ME dipole array is fabricated on a single layer of the RT/duroid 5880 substrate. The proposed antenna exhibits a measured −10 dB impedance bandwidth of 14.5 GHz (52% at 28 GHz) and a maximal peak realized gain of 20.44 dBi at 27.5 GHz with a 3 dB gain bandwidth of 3.5 GHz (12.5% at 28 GHz). The proposed antenna array is a good candidate for 5G communication applications due to its advantages of simple feeding structure, wide bandwidth, high gain, and low profile. [ABSTRACT FROM AUTHOR]

In this study, the emergence rate, emergence potential, root length, stem length, water consumption, and biomass around a root system were used as evaluation indexes, and we used the laboratory-prepared super absorbent resin watermelon rind (WMR)-p (AA–co–DAAM) (superabsorbent polymer 1—SAP1), WMR-p (AA–co–DAAM)/palygorskite (PGS) (SAP2) in a laboratory and commercially available water-retaining agents (SAPRX and SAPHDB) to assist the emergence of Artemisiadesertorum seeds and seedling growth; then, their water absorption and thermal stability were discussed. The results showed that the thermal stability of an SAP prepared in the laboratory and the water consumption during seed emergence, root length, and stem length after emergence were better than those of an SAP purchased on the market, and this information could help to promote the emergence and seedling growth of Artemisiadesertorum. While enhancing the drought resistance of plants, using a laboratory-produced SAP can effectively reduce the number of artificial irrigations. [ABSTRACT FROM AUTHOR]

Neither of the two typical two-dimensional materials, graphene and single layer MoS 2 , are good enough for developing semiconductor logical devices. We calculated the electron mobility of 14 two-dimensional semiconductors with composition of MX 2 , where M (=Mo, W, Sn, Hf, Zr and Pt) are transition metals, and Xs are S, Se and Te. We approximated the electron phonon scattering matrix by deformation potentials, within which long wave longitudinal acoustical and optical phonon scatterings were included. Piezoelectric scattering in the compounds without inversion symmetry is also taken into account. We found that out of the 14 compounds, WS 2 , PtS 2 and PtSe 2 are promising for logical devices regarding the possible high electron mobility and finite band gap. Especially, the phonon limited electron mobility in PtSe 2 reaches about 4000 cm 2 ·V - 1 ·s - 1 at room temperature, which is the highest among the compounds with an indirect bandgap of about 1.25 eV under the local density approximation. Our results can be the first guide for experiments to synthesize better two-dimensional materials for future semiconductor devices.