A family of photocatalysts for water splitting into hydrogen was prepared by distributing TiO(6) units in an MTi-layered double hydroxide matrix (M = Ni, Zn, Mg) that displays largely enhanced photocatalytic activity with an H(2)-production rate of 31.4 μmol  h(-1) as well as excellent recyclable performance. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) mapping and XPS measurement reveal that a high dispersion of TiO(6) octahedra in the layered doubled hydroxide (LDH) matrix was obtained by the formation of an M(2+)-O-Ti network, rather different from the aggregation state of TiO(6) in the inorganic layered material K(2)Ti(4)O(9). Both transient absorption and photoluminescence spectra demonstrate that the electron-hole recombination process was significantly depressed in the Ti-containing LDH materials relative to bulk Ti oxide, which is attributed to the abundant surface defects that serve as trapping sites for photogenerated electrons verified by positron annihilation and extended X-ray absorption fine structure (EXAFS) techniques. In addition, a theoretical study on the basis of DFT calculations demonstrates that the electronic structure of the TiO(6) units was modified by the adjacent MO(6) octahedron by means of covalent interactions, with a much decreased bandgap of 2.1 eV, which accounts for its superior water-splitting behavior. Therefore, the dispersion strategy for TiO(6) units within a 2D inorganic matrix can be extended to fabricate other oxide or hydroxide catalysts with greatly enhanced performance in photocatalysis and energy conversion.

The transition from vegetative to reproductive growth is very important for early maturity in cotton. However, the genetic control of this highly dynamic and complex developmental process remains unclear. A high-resolution tissue-and stage-specific transcriptome profile was generated from six developmental stages using 72 samples of two early-maturing and two late-maturing cotton varieties. The results of histological analysis of paraffin sections showed that flower bud differentiation occurred at the third true leaf stage (3TLS) in early-maturing varieties, but at the fifth true leaf stage (5TLS) in late-maturing varieties. Using pairwise comparison and weighted gene co-expression network analysis, 5312 differentially expressed genes were obtained, which were divided into 10 gene co-expression modules. In the MElightcyan module, 46 candidate genes regulating cotton flower bud differentiation were identified and expressed at the flower bud differentiation stage. A novel key regulatory gene related to flower bud differentiation, GhCAL, was identified in the MElightcyan module. Anti-GhCAL transgenic cotton plants exhibited late flower bud differentiation and flowering time. GhCAL formed heterodimers with GhAP1-A04/GhAGL6-D09 and regulated the expression of GhAP1-A04 and GhAGL6-D09. GhAP1-A04-and GhAGL6-D09-silenced plants also showed significant late flowering. Finally, we propose a new flowering regulatory pathway mediated by GhCAL. This study elucidated the molecular mechanism of cotton flowering regulation and provides good genetic resources for cotton early-maturing breeding.

The glycosyltransferase (GT) 47 family is involved in the biosynthesis of xylose, pectin and xyloglucan and plays a significant role in maintaining the normal morphology of the plant cell wall. However, the functions of GT47s are less well known in cotton. In the present study, a total of 53, 53, 105 and 109 GT47 genes were detected by genome-wide identification in Gossypium arboreum, G. raimondii, G. hirsutum and G. barbadense, respectively. All the GT47s were classified into six major groups via phylogenetic analysis. The exon/intron structure and protein motifs indicated that each branch of the GT47 genes was highly conserved. Collinearity analysis showed that GT47 gene family expansion occurred in Gossypium spp. mainly through whole-genome duplication and that segmental duplication mainly promoted GT47 gene expansion within the A and D subgenomes. The Ka/Ks values suggested that the GT47 gene family has undergone purifying selection during the long-term evolutionary process. Transcriptomic data and qRT-PCR showed that GhGT47 genes exhibited different expression patterns in each tissue and during fiber development. Our results suggest that some genes in the GhGT47 family might be associated with fiber development and the abiotic stress response, which could promote further research involving functional analysis of GT47 genes in cotton.

SET (Su(var), E(z), and Trithorax) domain-containing proteins play an important role in plant development and stress responses through modifying lysine methylation status of histone. Gossypium raimondii may be the putative contributor of the D-subgenome of economical crops allotetraploid G. hirsutum and G. barbadense and therefore can potentially provide resistance genes. In this study, we identified 52 SET domain-containing genes from G. raimondii genome. Based on conserved sequences, these genes are grouped into seven classes and are predicted to catalyze the methylation of different substrates: GrKMT1 for H3K9me, GrKMT2 and GrKMT7 for H3K4me, GrKMT3 for H3K36me, GrKMT6 for H3K27me, but GrRBCMT and GrS-ET for nonhistones substrate-specific methylation. Seven pairs of GrKMT and GrRBCMT homologous genes are found to be duplicated, possibly one originating from tandem duplication and five from a large scale or whole genome duplication event. The gene structure, domain organization and expression patterns analyses suggest that these genes’ functions are diversified. A few of GrKMTs and GrRBCMTs, especially for GrKMT1A;1a, GrKMT3;3 and GrKMT6B;1 were affected by high temperature (HT) stress, demonstrating dramatically changed expression patterns. The characterization of SET domain-containing genes in G. raimondii provides useful clues for further revealing epigenetic regulation under HT and function diversification during evolution.

Underwater terrain matching navigation technology is an important research area for the underwater navigation of Autonomous Underwater Vehicles (AUVs). Terrain matching navigation can realise long-term, subtle, all-weather, and high-precision underwater AUV navigation. In this paper, the research status of the application of AUV underwater terrain matching navigation is reviewed, the system composition, theory and terrain matching methods of underwater terrain matching navigation are summarised and the advantages of a multi-beam bathymetric system in underwater terrain matching navigation are discussed. The current research thoughts are summarised, the key issues are pointed out, and possible future development trends are discussed.

Two porous coordination polymers, { [ C o 0 . 5 ( T B C ) ] • 2 D M F } n ( 1 ) a n d { [ C o ( T B C ) -Cl 0.5 (CH 3 OH)]•0.5Cl} n (2), were synthesized via the solvothermal reaction of cobalt(II) salts and 3,5-bis(1H-1,2,4-triazol-1-yl)benzenecarboxylic acid. Single-crystal X-ray diffraction analyses exhibited that complex 1 contains rtl three-dimensional (3D) skeleton and one-dimensional channels with large apertures, while complex 2 displays a novel 2-nodal 3,6-linked 3D structure with a Schlafi sign of {4.8 2 } 2 {4 6 .8 9 } and contains micropores. Meanwhile, compound 2 shows selective adsorption properties of anionic methyl orange in a water solution. The dye adsorption studies of 1 and 2 revealed that the porous character and charge properties of metal−organic frameworks are two important factors heavily influencing dye adsorption.

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