Chromosome-level genome assembly of a regenerable maize inbred line A188

Background: The maize inbred line A188 is an attractive model for elucidation of gene function and improvement due to its high embryogenic capacity and many contrasting traits to the first maize reference genome, B73, and other elite lines. The lack of a genome assembly of A188 limits its use as a model for functional studies. Results: Here, we present a chromosome-level genome assembly of A188 using long reads and optical maps. Comparison of A188 with B73 using both whole-genome alignments and read depths from sequencing reads identify approximately 1.1 Gb of syntenic sequences as well as extensive structural variation, including a 1.8-Mb duplication containing the Gametophyte factor1 locus for unilateral cross-incompatibility, and six inversions of 0.7 Mb or greater. Increased copy number of carotenoid cleavage dioxygenase 1 (ccd1) in A188 is associated with elevated expression during seed development. High ccd1 expression in seeds together with low expression of yellow endosperm 1 (y1) reduces carotenoid accumulation, accounting for the white seed phenotype of A188. Furthermore, transcriptome and epigenome analyses reveal enhanced expression of defense pathways and altered DNA methylation patterns of the embryonic callus. Conclusions: The A188 genome assembly provides a high-resolution sequence for a complex genome species and a foundational resource for analyses of genome variation and gene function in maize. The genome, in comparison to B73, contains extensive intra-species structural variations and other genetic differences. Expression and network analyses identify discrete profiles for embryonic callus and other tissues

Chromosome-level genome assembly of a regenerable maize inbred line A188.

BACKGROUND The maize inbred line A188 is an attractive model for elucidation of gene function and improvement due to its high embryogenic capacity and many contrasting traits to the first maize reference genome, B73, and other elite lines. The lack of a genome assembly of A188 limits its use as a model for functional studies. RESULTS Here, we present a chromosome-level genome assembly of A188 using long reads and optical maps. Comparison of A188 with B73 using both whole-genome alignments and read depths from sequencing reads identify approximately 1.1 Gb of syntenic sequences as well as extensive structural variation, including a 1.8-Mb duplication containing the Gametophyte factor1 locus for unilateral cross-incompatibility, and six inversions of 0.7 Mb or greater. Increased copy number of carotenoid cleavage dioxygenase 1 (ccd1) in A188 is associated with elevated expression during seed development. High ccd1 expression in seeds together with low expression of yellow endosperm 1 (y1) reduces carotenoid accumulation, accounting for the white seed phenotype of A188. Furthermore, transcriptome and epigenome analyses reveal enhanced expression of defense pathways and altered DNA methylation patterns of the embryonic callus. CONCLUSIONS The A188 genome assembly provides a high-resolution sequence for a complex genome species and a foundational resource for analyses of genome variation and gene function in maize. The genome, in comparison to B73, contains extensive intra-species structural variations and other genetic differences. Expression and network analyses identify discrete profiles for embryonic callus and other tissues

Investigation of Improved Methods in Power Transfer Efficiency for Radiating Near-Field Wireless Power Transfer

A metamaterial-inspired efficient electrically small antenna is proposed, firstly. And then several improving power transfer efficiency (PTE) methods for wireless power transfer (WPT) systems composed of the proposed antenna in the radiating near-field region are investigated. Method one is using a proposed antenna as a power retriever. This WPT system consisted of three proposed antennas: a transmitter, a receiver, and a retriever. The system is fed by only one power source. At a fixed distance from receiver to transmitter, the distance between the transmitter and the retriever is turned to maximize power transfer from the transmitter to the receiver. Method two is using two proposed antennas as transmitters and one antenna as receiver. The receiver is placed between the two transmitters. In this system, two power sources are used to feed the two transmitters, respectively. By adjusting the phase difference between the two feeding sources, the maximum PTE can be obtained at the optimal phase difference. Using the same configuration as method two, method three, where the maximum PTE can be increased by regulating the voltage (or power) ratio of the two feeding sources, is proposed. In addition, we combine the proposed methods to construct another two schemes, which improve the PTE at different extent than classical WPT system

Influence of electric vehicle access mode on the static voltage stability margin and accommodated capacity of the distribution network

The electric vehicle, if accessed in the distribution network disorderly and extensively, will influence the safe, stable, and economic operation of the network, due to the characteristics of its randomness, intermittency, and duality with source and load. Here, the power demand models of different electric vehicles were established by analysing the behaviour of electric vehicle loads attributed to different users, and the spatial-temporal distribution pattern of various electric vehicle loads in the distribution network was predicted with the Monte–Carlo method. Based on this regular pattern, an evaluation method for the adaptability of the distribution network to electric vehicles was proposed. Finally, the influence of electric vehicle loads under different access modes on the static voltage stability margin was tested with the IEEE33 node distribution network

High-performance intercalated composite solid electrolytes for lithium metal battery

Composite solid electrolytes (CSEs) combining the advantages of both inorganic and organic solid-state electrolytes, are expected to become the most promising solid electrolyte owning to their favorable interfaces with electrodes. However, low room-temperature ionic conductivity restricts the application of CSEs in lithium metal batteries. Herein, we design an intercalated CSE based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Kaolin (2SiO2-Al2O3-2H2O), employed as an oxidative flame retardant, imparts nonflammability to the material. The polar molecule dimethyl sulfoxide (DMSO) is inserted between the kaolin layers as the pre-intercalation treatment, serving as an organic additive within the PVDF-HFP based SPE. The intercalated structure of CSE provides rapid Li+ transport channels, resulting in a high ionic conductivity (8.58 × 10−4 S cm−1) and large Li+ transference number at room temperature. The Li||Li symmetrical cell with prepared CSE exhibits outstanding cyclic stability of over 1400 h at a current density of 0.2 mA cm−2 for the capacity of 0.2 mAh cm−2. Moreover, the assembled Li||LiFePO4 cell delivers a high initial capacity of 140.5 mAh g−1 with a capacity retention of 81.2 % after 800 cycles at 0.5 C. In this paper, we present a novel approach for constructing high-performance solid-state lithium metal batteries

Highly Conductive Hierarchical TiO2 Micro-Sheet Enables Thick Electrodes in Sodium Storage

TiO2-based materials are considered to be the promising anodes of sodium-ion batteries (NIBs) because of their high safety and good stability. However, their low specific capacity and high safety operating voltage plateau impose a severe challenge for high energy density batteries. Herein, interconnected micro-sheets consisting of carbon nanotubes and sulfur doped TiO2 (CNT/S-TiO2) are synthesized via an ultrasonic process and subsequent calcination, enabling the fabrication of high-performance material. The utilization of SWCNT overcomes the structure instabilities during electrode preparation of thick electrodes. The incorporation of SWCNT and sulfur dopants in the CNT/S-TiO2 composite not only enhances conductivity but also improves ion transport dynamics, resulting in rapid charge delivery and high specific capacity at the thick electrode level. Consequently, CNT/S-TiO2 demonstrates excellent rate performance (from 0.3 to 15 C, with 72.4% capacity retention) and long cycling stability (10000 cycles at a load of 1.96 mg cm−2). More importantly, the high S-TiO2 content (90%) in the thick electrode (21.2 mg cm−2) achieves a high areal capacity retention of 3.4 mA h cm−2 after 100 cycles, which surpasses the actual application requirements

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To develop a carbon material derived from a green biomass source, this study investigated the production of a derivatized carbon material made from an industrial byproduct, litchi pericarp, through a hydrothermal reaction combined with a high-temperature heat treatment process, and its application in a new energy field was evaluated. Gratifyingly, in the field of sodium ion batteries, the material showed excellent electrochemical performance when evaluated as an anode: the material exhibited a high initial reversible capacity (336.4 mAh/g), an excellent retention rate (98.6%) after 120 cycles and good rate performance (183.2 mAh/g at 500 mA/g). The energy storage mechanism in the material was also determined. Moreover, for a fuel in direct carbon solid oxide fuel cells, the maximum power density was 239 mW/cm at 850 °C. When operating at a constant current density of 250 mA/cm , the cell also displayed a stable discharging voltage and platform, and the fuel utilization rate was 66%. As a promising green carbon material with high electrochemical performance, the developed litchi pericarp-derived carbon material shows great potential in the new energy industry. 2

Construction of robust solid-electrolyte interphase via electrode additive for high-performance Sn-based anodes of sodium-ion batteries

Alloy-based Sn anode for sodium-ion batteries has attracted tremendous attention due to its low working voltage, high specific capacity, and good availability. Its application is hindered, however, by inferior cycling stability due to its huge volume changes and unstable solid-electrolyte interphase (SEI) film. Herein, tetraphenylphosphonium bis(trifluoromethanesulfonyl)imide (TPPTFSI) is introduced into the electrode and spontaneously adsorbed on the surfaces of commercial Sn microparticles (μ-Sn) to improve the electrochemical performance of the Sn anode. In the first cycle, the TPP+ component of TPPTFSI decomposes to form an organic component of the SEI film, thereby enhancing its flexibility. Meanwhile, the TFSI− component is converted into an inorganic constituent of the SEI, improving its robustness and ionic conductivity. Therefore, the cycling performance of the μ-Sn is enhanced significantly. The modified electrode, TPPTFSI-Sn, delivers a capacity of 619.7 mAh g−1 after 2000 cycles at 2.0 A g−1, while the control sample can only survive for 30 cycles. Importantly, the full cell also exhibits excellent performance, including rate performance and cycling stability. Its simple operation and remarkable electrochemical performance improvement indicate the promising prospects of this strategy for advanced electrodes in SIBs