The equilibria of Ta-W-Al-Si-O system at 1200 °C

Solid reactions among Ta-W-Al-Si oxides are discussed and the phase compatibilities of these oxides at 1200 °C have been investigated. The results showed that complex oxides of TaWO, TaWO, TaWO, AlWO and AlTaO could be formed by solid reactions. Liquid phase formed by AlO-WO in WO-SiO-AlO benefits the mullitization reaction, thus mullite can be formed at 1200 °C in ternary system. Solid solution with a formula of (1-x)TaO·xWO was formed, and up to 25.0% SiO and 6.0% AlO can be dissolved in the solid solution. Liquid phase first appeared in the TaO-WO-AlO ternary system at 1300 °C in the WO-rich corner. As the temperature increased, the liquidus area expanded towards the AlO- and the TaO-rich corners

Phase relations in the Ta2O5-WO3-SiO2 system

Subsolidus relations and liquidus boundaries in the TaO-WO-SiO system at temperatures ranging from 1200 °C to 1500 °C were investigated. Phase diagrams were constructed. Compounds with stoichiometries of TaWO, TaWO and TaWO formed in the TaO-WO subsystem at 1200 °C. SiO was compatible with each of the compounds. A solid solution with a formula of (1 − x) TaO·xWO formed on the TaO-WO line in the compositional range of TaO:WO > 11:4. SiO had a maximum solubility of 25% SiO in the solid solution. Liquid phase first appeared in the WO-rich corner at 1300 °C. As the temperature was increased up to 1500 °C, the liquidus area boundary gradually expanded towards the SiO- and the TaO-rich corners

Identification of Key Modules and Candidate Genes for Powdery Mildew Resistance of Wheat-<i>Agropyron cristatum</i> Translocation Line WAT-2020-17-6 by WGCNA

As one of the serious diseases of wheat, powdery mildew (Blumeria graminis f. sp. tritici) is a long-term threat to wheat production. Therefore, it is of great significance to explore new powdery mildew-resistant genes for breeding. The wild relative species of wheat provide gene resources for resistance to powdery mildew breeding. Agropyron cristatum (2n = 4x = 28, genomes PPPP) is an important wild relative of wheat, carrying excellent genes for high yield, disease resistance, and stress resistance, which can be used for wheat improvement. To understand the molecular mechanism of powdery mildew resistance in the wheat-A. cristatum translocation line WAT2020-17-6, transcriptome sequencing was performed, and the resistance genes were analyzed by weighted gene co-expression network analysis (WGCNA). In the results, 42,845 differentially expressed genes were identified and divided into 18 modules, of which six modules were highly correlated with powdery mildew resistance. Gene ontology (GO) enrichment analysis showed that the six interested modules related to powdery mildew resistance were significantly enriched in N-methyltransferase activity, autophagy, mRNA splicing via spliceosome, chloroplast envelope, and AMP binding. The candidate hub genes of the interested modules were further identified, and their regulatory relationships were analyzed based on co-expression data. The temporal expression pattern of the 12 hub genes was verified within 96 h after powdery mildew inoculation by RT-PCR assay. In this study, we preliminarily explained the resistance mechanism of the wheat-A. cristatum translocation lines and obtained the hub candidate genes, which laid a foundation in the exploration of resistance genes in A. cristatum for powdery mildew-resistant breeding in wheat

Comparative Transcriptomes Analysis of Red- and White-Fleshed Apples in an F1 Population of Malus sieversii f. niedzwetzkyana Crossed with M. domestica 'Fuji'.

Transcriptome profiles of the red- and white-fleshed apples in an F1 segregating population of Malus sieversii f.Niedzwetzkyana and M.domestica 'Fuji' were generated using the next-generation high-throughput RNA sequencing (RNA-Seq) technology and compared. A total of 114 differentially expressed genes (DEGs) were obtained, of which 88 were up-regulated and 26 were down-regulated in red-fleshed apples. The 88 up-regulated genes were enriched with those related to flavonoid biosynthetic process and stress responses. Further analysis identified 22 genes associated with flavonoid biosynthetic process and 68 genes that may be related to stress responses. Furthermore, the expression of 20 up-regulated candidate genes (10 related to flavonoid biosynthesis, two encoding MYB transcription factors and eight related to stress responses) and 10 down-regulated genes were validated by quantitative real-time PCR. After exploring the possible regulatory network, we speculated that flavonoid metabolism might be involved in stress responses in red-fleshed apple. Our findings provide a theoretical basis for further enriching gene resources associated with flavonoid synthesis and stress responses of fruit trees and for breeding elite apples with high flavonoid content and/or increased stress tolerances

Oxidative cleavage of -O-4 bonds in lignin model compounds with a single-atom Co catalyst

Single-atom catalysts are emerging as primary catalysts for many reactions due to their 100% utilization of active metal centers leading to high catalytic efficiencies. Herein, we report the use of a single-atom Co catalyst for the oxidative cleavage of the -O-4 bonds of lignin model compounds at a low oxygen pressure. Under the optimized reaction conditions, the conversion of 2-(2-methoxyphenoxy)-1-phenylethanol up to 95% with high selectivities was achieved with a variety of substrates investigated. The reusability of the Co catalyst with a high catalytic efficiency indicates its potential application in the oxidative cleavage of C-O bonds

High-quality Ruddlesden-Popper perovskite films based on in situ formed organic spacer cations

Ruddlesden-Popper perovskites (RPPs), consisting of alternating organic spacer layers and inorganic layers, have emerged as a promising alternative to 3D perovskites for both photovoltaic and light-emitting applications. The organic spacer layers provide a wide range of new possibilities to tune the properties and even provide new functionalities for RPPs. However, the preparation of state-of-the-art RPPs requires organic ammonium halides as the starting materials, which need to be ex situ synthesized. A novel approach to prepare high-quality RPP films through in situ formation of organic spacer cations from amines is presented. Compared with control devices fabricated from organic ammonium halides, this new approach results in similar (and even better) device performance for both solar cells and light-emitting diodes. High-quality RPP films are fabricated based on different types of amines, demonstrating the universality of the approach. This approach not only represents a new pathway to fabricate efficient devices based on RPPs, but also provides an effective method to screen new organic spacers with further improved performance.NRF (Natl Research Foundation, S’pore)MOE (Min. of Education, S’pore)Accepted versio

The USDA cucumber (Cucumis sativus L.) collection: genetic diversity, population structure, genome-wide association studies, and core collection development

Cucumber: Core collection for future crop improvement Genetic analysis of the US cucumber collection provides valuable insights into the plant’s diversity and generates a core resource for future research. Breeding crop plants requires in-depth understanding of plant genetics and the identification of key genes that enhance traits such as disease and stress resistance. Zhangjun Fei at the Boyce Thompson Institute in Ithaca, Rebecca Grumet at Michigan State University, and co-workers across the US used high-throughput genetic sequencing to characterize the 1,234 cucumber accessions held by the US National Plant Germplasm System. The team uncovered 23,000 specific genome variations that revealed the genetic diversity, population structure and genetic differentiation of the cucumber. They identified genome regions associated with 13 traits important to cultivation and selected 395 accessions covering 96 percent of the collection’s genetic variation to make a publicly accessible core of data