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Next-generation advanced high/pulsed power capacitors urgently require dielectric materials with outstanding energy storage performance. Bi0.5Na0.5TiO3-based lead-free materials exhibit high polarization, but the high remanent polarization and large polarization hysteresis limit their applications in dielectric capacitors. Herein, high-entropy perovskite relaxor ferroelectrics (Na0.2Bi0.2Ba0.2Sr0.2Ca0.2)(Ti1−x%Zrx%)O3 are designed by adding multiple ions in the A-site and replacing the B-site Ti4+ with a certain amount of Zr4+. The newly designed system showed high relaxor feature and slim polarization–electric (P–E) loops. Especially, improved relaxor feature and obviously delayed polarization saturation were found with the increasing of Zr4+. Of particular importance is that both high recoverable energy storage density of 6.6 J/cm3 and energy efficiency of 93.5% were achieved under 550 kV/cm for the ceramics of x = 6, accompanying with excellent frequency stability, appreciable thermal stability, and prosperous discharge property. This work not only provides potential dielectric materials for energy storage applications, but also offers an effective strategy to obtain dielectric ceramics with ultrahigh comprehensive energy storage performance to meet the demanding requirements of advanced energy storage applications.

A series of single-phase double perovskite Pr1-xGdxBaCo2-yFeyO5+δ (x = 0, 0.5 and 1, 0 ≤ y ≤ 1) materials were engineered through A/B site co-doping strategy to improve the mechanical, electrical and electrochemical properties as potential cathode materials for the application of intermediate solid oxide fuel cells (IT-SOFCs). The corresponding thermochemical stability, thermal expansion behavior, electrical conductivity and cathodic polarization resistance of the materials were systematically investigated. It was found that the A-site dual lanthanide doped Pr0.5Gd0.5BaCo2O5+δ (PGBCO) exhibits improved electrical conductivity, reduced thermal expansion, and comparatively low electrochemical polarization resistance versus single lanthanide double perovskite, PrBaCo2O5+δ (PBCO) and GdBaCo2O5+δ (GBCO) materials. Further investigation on the effect of B-site Fe-doping on Pr0.5Gd0.5BaCo2-yFeyO5+δ (PGBCF-y, 0 ≤ y ≤ 1) reveals that all the PGBCF-y compositions exhibit excellent chemical stability with Gd-doped ceria (GDC) at operating temperatures not higher than 1 100 °C. Besides, doping of Fe in B-site can effectively reduce the thermal expansion coefficients (TECs) of the Pr0.5Gd0.5BaCo2O5+δ ceramics at 30–1 000 °C. And the electrochemical impedance spectra (EIS) results show that the PGBCF-y|GDC| PGBCF-y symmetric cells have acceptable low area specific polarization resistances. Further examination of the cathodic polarization and characteristic capacitance from the AC impedance spectra by employing the relaxation time distribution (DRT) method demonstrated that charge transfer is the dominating sub-process for the oxygen transport through the materials.

Here, the authors design NaNbO3 based ceramics with the aim of enabling a field-induced reversible phase transformation between the antiferroelectric and ferroelectric phases, which manifests itself in a well-defined double hysteresis loop in the P-E hysteresis curve.

Evidence suggests city grouping is an important way to implement urbanization in China. However, the Chengdu-Chongqing Economic Circle (CCEC) is a typical dual-core structure, and the development level of each city is different. If we do not focus on the key directions for urban development, it will not be conducive to the new-type urbanization process. Therefore, we use spatial analysis techniques and geographic big data sets to construct an approach for urban system layout optimization from a global perspective. It mainly includes urban extended trend analysis based on night light, multi-modal traffic network analysis, and spatial economic density analysis using Open Street Map (OSM) and Point of Interest (POI) data. The research results show the following interesting findings. Firstly, the historical relationship of cities has a significant impact on city grouping, and efficient transportation connections and prosperous enterprise distribution are key conditions for urban grouping during the acceleration period of urbanization. Secondly, the development of urban grouping should break through administrative restrictions and achieve a moderate separation of administrative divisions and economic divisions. It is beneficial to the rapid growth of the city group and the improvement of the internal structure. Thirdly, the urban group of Southern Sichuan and Western Chongqing (SSWC) is the region with the most potential for growth in CCEC. The urban expansion index (UEI) of the Yibin-Luzhou area is 2.16, and the spatial economic density has increased by 130/km2 in the past decade. Providing flexible development authority and focus on the construction of the Yibin-Luzhou Urban Belt along the Yangtze River is an important way to integrate southern Sichuan. Moreover, we found the UEI has a good universality and it can be used for studying urban expansion trends and city relationships in rapidly developing regions, especially in metropolitan areas or urban agglomeration.

Bi-based YbMg2Bi1.98 Zintl compounds represent promising thermoelectric materials. Precise composition and appropriate doping are of great importance for this complex semiconductor. Here, the influence of Zn substitution for Mg on the microstructure and thermoelectric properties of p-type YbMg1.85−xZnxBi1.98 (x = 0, 0.05, 0.08, 0.13, 0.23) was investigated. Polycrystalline samples were prepared using induction melting and densified with spark plasma sintering. X-ray diffraction confirmed that the major phase of the samples possesses the trigonal CaAl2Si2-type crystal structure, and SEM/EDS indicated the presence of minor secondary phases. The electrical conductivity increases and the lattice thermal conductivity decreases with more Zn doping in YbMg1.85−xZnxBi1.98, whereas the Seebeck coefficient has a large reduction. The band gap decreases with increasing Zn concentration and leads to bipolar conduction, resulting in an increase in the thermal conductivity at higher temperatures. Figure of merit ZT values of 0.51 and 0.49 were found for the samples with x = 0 and 0.05 at 773 K, respectively. The maximum amount of Zn doping is suggested to be less than x = 0.1.

Abstract Background Low temperature is a crucial stress factor of wheat (Triticum aestivum L.) and adversely impacts on plant growth and grain yield. Multi-million tons of grain production are lost annually because crops lack the resistance to survive in winter. Particularlly, winter wheat yields was severely damaged under extreme cold conditions. However, studies about the transcriptional and metabolic mechanisms underlying cold stresses in wheat are limited so far. Results In this study, 14,466 differentially expressed genes (DEGs) were obtained between wild-type and cold-sensitive mutants, of which 5278 DEGs were acquired after cold treatment. 88 differential accumulated metabolites (DAMs) were detected, including P-coumaroyl putrescine of alkaloids, D-proline betaine of mino acids and derivativ, Chlorogenic acid of the Phenolic acids. The comprehensive analysis of metabolomics and transcriptome showed that the cold resistance of wheat was closely related to 13 metabolites and 14 key enzymes in the flavonol biosynthesis pathway. The 7 enhanced energy metabolites and 8 up-regulation key enzymes were also compactly involved in the sucrose and amino acid biosynthesis pathway. Moreover, quantitative real-time PCR (qRT-PCR) revealed that twelve key genes were differentially expressed under cold, indicating that candidate genes POD, Tacr7, UGTs, and GSTU6 which were related to cold resistance of wheat. Conclusions In this study, we obtained the differentially expressed genes and differential accumulated metabolites in wheat under cold stress. Using the DEGs and DAMs, we plotted regulatory pathway maps of the flavonol biosynthesis pathway, sucrose and amino acid biosynthesis pathway related to cold resistance of wheat. It was found that candidate genes POD, Tacr7, UGTs and GSTU6 are related to cold resistance of wheat. This study provided valuable molecular information and new genetic engineering clues for the further study on plant resistance to cold stress.

Sitophilus zeamais (maize weevil) is one of the most destructive pests that seriously affects the quantity and quality of wheat (Triticum aestivum L.). However, little is known about the constitutive defense mechanism of wheat kernels against maize weevils. In this study, we obtained a highly resistant variety RIL-116 and a highly susceptible variety after two years of screening. The morphological observations and germination rates of wheat kernels after feeding ad libitum showed that the degree of infection in RIL-116 was far less than that in RIL-72. The combined analysis of metabolome and transcriptome of RIL-116 and RIL-72 wheat kernels revealed differentially accumulated metabolites were mainly enriched in flavonoids biosynthesis-related pathway, followed by glyoxylate and dicarboxylate metabolism, and benzoxazinoid biosynthesis. Several flavonoids metabolites were significantly up-accumulated in resistant variety RIL-116. In addition, the expression of structural genes and transcription factors (TFs) related to flavonoids biosynthesis were up-regulated to varying degrees in RIL-116 than RIL-72. Taken together, these results indicated that the biosynthesis and accumulation of flavonoids contributes the most to wheat kernels defense against maize weevils. This study not only provides insights into the constitutive defense mechanism of wheat kernels against maize weevils, but may also play an important role in the breeding of resistant varieties.

Wheat as a staple food crop is enduring ever-frequent intermittent and changing drought with the climate change. It is of great significance to highlight the adaptive approaches under such variable conditions at multiple levels to provide a comprehensive understanding of drought tolerance and facilitate the genetic breeding of wheat. Therefore, three wheat lines with different drought tolerance (drought-tolerant mutant Mu > common wheat CK > drought susceptible mutant mu) were analyzed under moderate and severe drought stresses as well as rehydration. Samples were subjected to transcriptomic and metabolomic profiling in combination with physiological and biochemical determination. The moderate drought stress rendered 198 and 115 differentially expressed metabolites (DEMs) in CK and Mu, respectively. The severe drought stress rendered 166, 151 and 137 DEMs in CK, Mu and mu, respectively. The rehydration rendered 150 and 127 DEMs in CK and Mu. 12,557 and 10,402 differentially expressed genes (DEGs) were identified for CK and Mu under moderate drought stress, respectively. 9,893, 7,924, and 9,387 DEGs were identified for CK, Mu, and mu under severe drought stress, respectively. 13,874 and 14,839 were identified in CK and Mu under rehydration, respectively. Metabolomics results showed that amino acid was the most differentially expressed metabolites, followed by phenolic acids. Flavonoids played an important role in drought tolerance. Most enriched pathways under drought included biosynthesis of secondary metabolites, metabolic pathways and photosynthesis. Metabolites and genes involved in osmotic regulation, antioxidase activities, and ABA signaling were more enriched in Mu than in CK and mu. Various drought-responsive genes and metabolites in Mu showed different trends with those in CK and mu. Increased amino acids biosynthetic capability and ROS scavenging ability resulted from higher antioxidase activities and increased flavonoids may be the mechanisms underlying the drought tolerance characteristic of Mu. Recovery from reversible ROS damage and rapid amino acid biosynthesis may contribute to the rapid recovery of Mu. The present study provides new insights for mechanisms of wheat under complex drought conditions.

Cytokinin is an important endogenous hormone in plants performing a wide spectrum of biological roles. The type-A response regulators (RRAs) are primary cytokinin response genes, which are important components of the cytokinin signaling pathway and are involved in the regulation of plant growth and development. By analysis of the whole genome sequence of wheat, we identified 20 genes encoding RRAs which were clustered into eight homologous groups. The gene structure, conserved motifs, chromosomal location, and cis-acting regulatory elements of the TaRRAs were analyzed. Quantitative real-time polymerase chain reaction (qRT-PCR) results showed that the expression levels of most of the TaRRAs increased rapidly on exogenous cytokinin application. Moreover, the TaRRA family members displayed different expression profiles under the stress treatments of drought, salt, cold, and heat. This study provides valuable insights into the RRA gene family in wheat and promotes the potential application of these genes in wheat genetic improvement.

Abstract The regulation of wheat protein quality is a highly complex biological process involving multiple metabolic pathways. To reveal new insights into the regulatory pathways of wheat glutenin synthesis, we used the grain-filling period wheat grains of the near-isogenic lines NIL-723 and NIL-1010, which have large differences in quality, to perform a combined transcriptome and proteome analysis. Compared with NIL-1010, NIL-723 had 1287 transcripts and 355 proteins with significantly different abundances. Certain key significantly enriched pathway were identified, and wheat quality was associated with alanine, aspartate and glutamate metabolism, nitrogen metabolism and alpha-linolenic acid metabolism. Differentially expressed proteins (DEPs) or Differentially expressed genes (DEGs) in amino acid synthesis pathways were upregulated primarily in the glycine (Gly), methionine (Met), threonine (Thr), glutamic acid (Glu), proline (proC), cysteine (Cys), and arginine (Arg) synthesis and downregulated in the tryptophan (trpE), leucine (leuC), citrulline (argE), and ornithine (argE) synthesis. Furthermore, to elucidate changes in glutenin in the grain synthesis pathway, we plotted a regulatory pathway map and found that DEGs and DEPs in ribosomes (RPL5) and the ER (HSPA5, HYOU1, PDIA3, PDIA1, Sec24, and Sec31) may play key roles in regulating glutenin synthesis. The transcriptional validation of some of the differentially expressed proteins through real-time quantitative PCR analysis further validated the transcriptome and proteomic results.

Double-layered manganites are natural superlattices with low thermal conductivity, which is of importance for potential thermoelectric applications. The Gd2−2xSr1+2xMn2O7 (x = 0.5; 0.625; 0.75) were prepared by the solid-state reaction method. All the samples crystallize in the tetragonal I4/mmm Sr3Ti2O7 type structure. The unit cell volume and the distortion in the MnO6 octahedra increase with increasing Gd content. Their thermoelectric properties were investigated between 300 and 1200 K. All exhibit an n-type semiconducting behavior. The electrical conductivity (σ) increases while the absolute value of the Seebeck coefficient (|S|) decreases with increasing Gd content. Simultaneous increases in σ and |S| with increasing temperature are observed at temperatures approximately higher than 600 K, and the power factor reaches a maximum value of 18.36 μW/(m K²) for x = 0.75 at 1200 K. The thermal conductivity (κ) is lower than 2 W/(m K) over the temperature range of 300–1000 K for all the samples and a maximum dimensionless figure of merit ZT of 0.01 is obtained for x = 0.75 at 1000 K.

Abstract Starch is the main component of wheat (Triticum aestivum L.) grain and a key factor in determining wheat processing quality. The Wx gene is the gene responsible for amylose synthesis. An ethyl methanesulfonate (EMS) mutagenized population was generated using common wheat cv. Gao 8901, a popular and high-quality cultivar in China. A waxy mutant (Wx-null) was isolated by screening M3 seeds with KI-I2 staining of endosperm starch. No obvious waxy proteins in Wx-null line were detected using Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). DNA sequencing revealed three SNPs and a 3-bp InDel in the first exon, and a 16-bp InDel at the junction region of the first Wx-A1 intron from the Wx-null line. Six SNPs were identified in Wx-B1 gene of Wx-null line compared to the wild-type Gao 8901, including four missense mutations. One nonsense mutation was found at position 857 in the fourth exon, which resulted in a premature stop codon. Expression levels of Wx genes were dramatically reduced in the Wx-null line. There were no detectable differences in granule size and morphology between Wx-null and wild-type, but the Wx-null line contained more B-type starch granules. The amylose content of the Wx-null line (0.22%) was remarkably lower compared to the wild-type Gao 8901 (24.71%). Total starch is also lower in the Wx-null line. The Wx-null line may provide a potential waxy material with high agronomic performance in wheat breeding programs.

Dielectric capacitors are widely used in electronic systems but they possess inferior energy density in comparison with other electrochemical energy storage. Here, the authors construct a diffused phase boundary to simultaneously achieve high energy storage density and efficiency in AgNbO3antiferroelectrics.

Both sustainable development in environment and safety of high-power systems require to develop a novel lead-free dielectric capacitor with high energy density (Wrec) at low applied electric field. In this work, a remarkably high Wrec of 2.9 J/cm3 accompanying with energy storage efficiency of 56% was achieved in Ag0.9Sr0.05NbO3 ceramic at a low applied electric field of 190 kV/cm, by improving anti-ferroelectricity and introducing relaxor behaviour. The improved anti-ferroelectric stability was attributed to the decreased tolerance factor and average electronegativity difference, while the relaxor behaviour was associated with the increased disordered local structure by Sr-doping. Moreover, the Ag0.9Sr0.05NbO3 ceramics also exhibited outstanding temperature stability in energy density with small variation less than 5% over 20–140 °C. The results indicate that the Ag0.9Sr0.05NbO3 ceramic is a promising candidate for low-electric-field driving capacitors. Keywords: Low applied electric field, Energy storage, Relaxor behaviour, Silver niobate, Anti-ferroelectric

Rhizoctonia cerealis is the causal agent of sharp eyespot, a devastating disease of cereal crops including wheat. Several metalloproteases have been implicated in pathogenic virulence, but little is known about whole-genome metalloproteases in R. cerealis. In this study, a total of 116 metalloproteases-encoding genes were identified and characterized from the R. cerealis Rc207 genome. The gene expression profiles and phylogenetic relationship of 11 MEP36/fungalysin metalloproteases were examined during the fungal infection to wheat, and function of an upregulated secretory MEP36 named RcFL1 was validated. Of 11 MEP36 family metalloproteases, ten, except RcFL5, were predicted to be secreted proteins and nine encoding genes, but not RcFL5 and RcFL2, were expressed during the R. cerealis infection process. Phylogenetic analysis suggested that MEP36 metalloproteases in R. cerealis were closely related to those of Rhizoctonia solani but were remote to those of Bipolaris sorokiniana, Fusarium graminearum, F. pseudograminearum, and Pyricularia oryzae. Expression of RcFL1 was significantly upregulated during the infection process and induced plant cell death in wheat to promote the virulence of the pathogen. The MEP36 domain was necessary for the activities of RcFL1. Furthermore, RcFL1 could repress the expression of wheat genes coding for the chitin elicitor receptor kinase TaCERK1 and chitinases. These results suggest that this MEP36 metalloprotease RcFL1 may function as a virulence factor of R. cerealis through inhibiting host chitin-triggered immunity and chitinases. This study provides insights on pathogenic mechanisms of R. cerealis. RcFL1 likely is an important gene resource for improving resistance of wheat to R. cerealis through host-induced gene silencing strategy.

Abstract Background High-molecular-weight glutenin subunits (HMW-GS) play important roles in the elasticity of dough made from wheat. The HMW-GS null line is useful for studying the contribution of HMW-GS to the end-use quality of wheat. Methods In a previous work, we cloned the Glu-1E b x gene from Thinopyrum bessarabicum and introduced it into the wheat cultivar, Bobwhite. In addition to lines expressing the Glu-1E b x gene, we also obtained a transgenic line (LH-11) with all the HMW-GS genes silenced. The HMW-GS deletion was stably inherited as a dominant and conformed to Mendel’s laws. Expression levels of HMW-GS were determined by RT-PCR and epigenetic changes in methylation patterns and small RNAs were analyzed. Glutenins and gliadins were separated and quantitated by reversed-phase ultra-performance liquid chromatography. Measurement of glutenin macropolymer, and analysis of agronomic traits and end-use quality were also performed. Results DNA methylation and the presence of small double-stranded RNA may be the causes of post-transcriptional gene silencing in LH-11. The accumulation rate and final content of glutenin macropolymer (GMP) in LH-11 were significantly lower than in wild-type (WT) Bobwhite. The total protein content was not significantly affected as the total gliadin content increased in LH-11 compared to WT. Deletion of HMW-GS also changed the content of different gliadin fractions. The ratio of ω-gliadin increased, whereas α/β- and γ-gliadins declined in LH-11. The wet gluten content, sedimentation value, development time and stability time of LH-11 were remarkably lower than that of Bobwhite. Bread cannot be made using the flour of LH-11. Conclusions Post-transcriptional gene silencing through epigenetic changes and RNA inhibition appear to be the causes for the gene expression deficiency in the transgenic line LH-11. The silencing of HMW-GW in LH-11 significantly reduced the dough properties, GMP content, wet gluten content, sedimentation value, development time and stability time of flour made from this wheat cultivar. The HMW-GS null line may provide a potential material for biscuit-making because of its low dough strength.

The lead–bismuth eutectic (LBE) can be easily activated by neutron radiation to produce the radionuclide 210Po. It is therefore necessary to establish an effective method to remove vaporized polonium in the cover gas to prevent its release into the air in scenarios of reactor maintenance and coolant leakage accidents. This paper presents a SiO2 nanofiber membrane prepared based on the electrostatic spinning and calcination process. The SiO2 nanofiber membrane had the advantages of good flexibility, high-temperature resistance, and corrosion resistance. In the trapping experiments, the SiO2 nanofiber membrane filters showed excellent filtration performance at 300~400 °C, and the filtration efficiencies for Te, Pb, and Bi could reach 99%, 99%, and 98%, respectively. Proper filtration temperature and gas flow rate are important to maintain high filtration efficiency. After five cycles, the SiO2 nanofiber membrane filter still exhibited excellent cycle-use performance. In the density functional theory (DFT) calculations, PbPo and PbTe had strong interactions with amorphous SiO2, having adhesion energies of −2.96 to −2.83 eV/molecule.

AimTo establish a gene co-expression network for identifying principal modules and hub genes that are associated with drought resistance mechanisms, analyzing their mechanisms, and exploring candidate genes.Methods and findings42 data sets including PRJNA380841 and PRJNA369686 were used to construct the co-expression network through weighted gene co-expression network analysis (WGCNA). A total of 1,896,897,901 (284.30 Gb) clean reads and 35,021 differentially expressed genes (DEGs) were obtained from 42 samples. Functional enrichment analysis indicated that photosynthesis, DNA replication, glycolysis/gluconeogenesis, starch and sucrose metabolism, arginine and proline metabolism, and cell cycle were significantly influenced by drought stress. Furthermore, the DEGs with similar expression patterns, detected by K-means clustering, were grouped into 29 clusters. Genes involved in the modules, such as dark turquoise, yellow, and brown, were found to be appreciably linked with drought resistance. Twelve central, greatly correlated genes in stage-specific modules were subsequently confirmed and validated at the transcription levels, including TraesCS7D01G417600.1 (PP2C), TraesCS5B01G565300.1 (ERF), TraesCS4A01G068200.1 (HSP), TraesCS2D01G033200.1 (HSP90), TraesCS6B01G425300.1 (RBD), TraesCS7A01G499200.1 (P450), TraesCS4A01G118400.1 (MYB), TraesCS2B01G415500.1 (STK), TraesCS1A01G129300.1 (MYB), TraesCS2D01G326900.1 (ALDH), TraesCS3D01G227400.1 (WRKY), and TraesCS3B01G144800.1 (GT).ConclusionsAnalyzing the response of wheat to drought stress during different growth stages, we have detected three modules and 12 hub genes that are associated with drought resistance mechanisms, and five of those genes are newly identified for drought resistance. The references provided by these modules will promote the understanding of the drought-resistance mechanism. In addition, the candidate genes can be used as a basis of transgenic or molecular marker-assisted selection for improving the drought resistance and increasing the yields of wheat.