Research on the Voltage Interaction of Multi-Infeed HVDC System and Interaction Factor

In multi-infeed HVDC system, the interactions and influences between DC systems AC systems are complex as the electrical distances among DC converter stations which are relatively short. Multi-infeed interaction factor (MIIF) can effectively reflect the interaction among DC systems. The paper theoretically analyzes the impact factors of MIIF like the electrical distances between two DC converter stations and the equivalent impedance of the receiving end AC system. By applying the Kirchhoff’s current law on the inverter AC bus, the paper deduces the analytical expressions for MIIF. From the expression, it is clear how the equivalent impedance of AC system and coupling impedance can affect MIIF. PSCAD simulations validate the effectiveness and the correctness of the proposed expression and some useful conclusions are drawn.

Flexible nanoimprint lithography enables high-throughput manufacturing of bioinspired microstructures on warped substrates for efficient III-nitride optoelectronic devices

III-nitride materials are of great importance in the development of modern optoelectronics,but they have been limited over years by low light utilization rate and high dislocation densities in heteroepitaxial films grown on foreign substrate with limited refractive index contrast and large lattice mismatches.Here,we demonstrate a paradigm of high-throughput manufacturing bioinspired microstructures on warped substrates by flexible nanoimprint lithography for promoting the light extraction capability.We design a flexible nanoimprinting mold of copolymer and a two-step etching process that enable high-efficiency fabrication of nanoimprinted compound-eye-like Al2O3 microstructure(NCAM)and nanoimprinted compound-eye-like SiO_(2)microstructure(NCSM)template,achieving a 6.4-fold increase in throughput and 25%savings in economic costs over stepper projection lithography.Compared to NCAM template,we find that the NCSM template can not only improve the light extraction capability,but also modulate the morphology of AlN nucleation layer and reduce the formation of misoriented GaN grains on the inclined sidewall of microstructures,which suppresses the dislocations generated during coalescence,resulting in 40%reduction in dislocation density.This study provides a low-cost,high-quality,and high-throughput solution for manufacturing microstructures on warped surfaces of III-nitride optoelectronic devices.

Pharmacological Activation of RXR-a Promotes Hematoma Absorption via a PPAR-y-dependent Pathway After Intracerebral Hemorrhage

Endogenously eliminating the hematoma is a favorable strategy in addressing intracerebral hemorrhage(ICH).This study sought to determine the role of retinoid X receptor-ot(RXR-a)in the context of hematoma absorption after ICH.Our results showed that pharmacologically activating RXR-a with bexarotene significantly accelerated hematoma clearance and alleviated neurological dysfunction after ICH.RXR-ot was expressed in microglia/macro-phages,neurons,and astrocytes.Mechanistically,bexarotene promoted the nuclear translocation of RXR-a and PPAR-y,as well as reducing neuroinflammation by modulating microglia/macrophage reprograming from the Ml into the M2 phenotype.Furthermore,all the beneficial effects of RXR-a in ICH were reversed by the PPAR-y inhibitor GW9662.In conclusion,the pharmacological activation of RXR-a confers robust neuroprotection against ICH by accelerating hematoma clearance and repolarizing microglia/macrophages towards the M2 phenotype through PPAR-y-related mechanisms.Our data support the notion that RXR-ot might be a promising therapeutic target for ICH.

Whole-genome resequencing of the wheat A subgenome progenitor Triticum urartu provides insights into its demographic history and geographic adaptation

Triticum urartu is the progenitor of the A subgenome in tetraploid and hexaploid wheat.Uncovering the landscape of genetic variations in T.urartu will help us understand the evolutionary and polyploid characteristics of wheat.Here,we investigated the population genomics of T.urartu by genome-wide sequencing of 59 representative accessions collected around the world.A total of 42.2 million highquality single-nucleotide polymorphisms and 3 million insertions and deletions were obtained by mapping reads to the reference genome.The ancient T.urartu population experienced a significant reduction in effective population size(Ne)from3000000 to140000 and subsequently split into eastern Mediterranean coastal and Mesopotamian-Transcaucasian populations during the Younger Dryas period.A map of allelic drift paths displayed splits and mixtures between different geographic groups,and a strong genetic drift towards hexaploid wheat was also observed,indicating that the direct donor of the A subgenome originated from northwestern Syria.Genetic changes were revealed between the eastern Mediterranean coastal and Mesopotamian-Transcaucasian populations in genes orthologous to those regulating plant development and stress responses.A genome-wide association study identified two single-nucleotide polymorphisms in the exonic regions of the SEMI-DWARF 37 ortholog that corresponded to the different T.urartu ecotype groups.Our study provides novel insights into the origin and genetic legacy of the A subgenome in polyploid wheat and contributes a gene repertoire for genomicsenabled improvements in wheat breeding.