7,422 research outputs found

    Influences of magnetic coupling process on the spectrum of a disk covered by the corona

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    Recently, much attention has been paid to the magnetic coupling (MC) process, which is supported by very high emissivity indexes observed in Seyfert 1 galaxy MCG-6-30-15 and GBHC XTE J1650-500. But the rotational energy transferred from a black hole is simply assumed to be radiated away from the surrounding accretion disk in black-body spectrum, which is obviously not consistent with the observed hard power-law X-ray spectra. We intend to introduce corona into the MC model to make it more compatible with the observations. We describe the model and the procedure of a simplified Monte Carlo simulation, compare the output spectra in the cases with and without the MC effects, and discuss the influences of three parameters involved in the MC process on the output spectra. It is shown that the MC process augments radiation fluxes in the UV or X-ray band. The emergent spectrum is affected by the BH spin and magnetic field strength at the BH horizon, while it is almost unaffected by the radial profile of the magnetic field at the disk. Introducing corona into the MC model will improve the fitting of the output spectra from AGNs and GBHCs.Comment: 15 pages, 5 figures, accepted by A&

    Annual hard frosts and economic growth

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    Induced Growth of Asymmetric Nanocantilever Arrays on Polar Surfaces

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    ©2003 The American Physical Society. The electronic version of this article is the complete one and can be found online at: http://link.aps.org/doi/10.1103/PhysRevLett.91.185502DOI: 10.1103/PhysRevLett.91.185502We report that the Zn-terminated ZnO (0001) polar surface is chemically active and the oxygenterminated (0001) polar surface is inert in the growth of nanocantilever arrays. Longer and wider "comblike" nanocantilever arrays are grown from the (0001)-Zn surface, which is suggested to be a self-catalyzed process due to the enrichment of Zn at the growth front. The chemically inactive (0001)-O surface typically does not initiate any growth, but controlling experimental conditions could lead to the growth of shorter and narrower nanocantilevers from the intersections between (0001)-O with (0110) surfaces

    Population genomics and haplotype analysis in bread wheat identify a gene regulating glume pubescence

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    Glume hairiness or pubescence is an important morphological trait with high heritability to distinguish/characterize wheat and is related to the resistance to biotic and abiotic stresses. Hg1 (formerly named Hg) on chromosome arm 1AS controlled glume hairiness in wheat. Its genetic analysis and mapping have been widely studied, yet more useful and accurate information for fine mapping of Hg1 and identification of its candidate gene is lacking. The cloning of this gene has not yet been reported for the large complex wheat genome. Here, we performed a GWAS between SNP markers and glume pubescence (Gp) in a wheat population with 352 lines and further demonstrated the gene expression and haplotype analysis approach for isolating the Hg1 gene. One gene, TraesCSU02G143200 (TaELD1-1A), encoding glycosyltransferase-like ELD1/KOBITO 1, was identified as the most promising candidate gene of Hg1. The gene annotation, expression pattern, function SNP variation, haplotype analysis, and co-expression analysis in floral organ (spike) development indicated that it is likely to be involved in the regulation of glume pubescence. Our study demonstrates the importance of high-quality reference genomes and annotation information, as well as bioinformatics analysis, for gene cloning in wheat

    The CCCH zinc finger family of soybean (Glycine max L.): genome-wide identification, expression, domestication, GWAS and haplotype analysis

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    Background The CCCH zinc finger (zf_CCCH) is a unique subfamily featured one or more zinc finger motif(s) comprising of three Cys and one His residues. The zf_CCCH family have been reported involving in various processes of plant development and adaptation. Results In this study, the zf_CCCH genes were identified via a genome-wide search and were systematically analyzed. 116 Gmzf_CCCHs were obtained and classified into seventeen subfamilies. Gene duplication and expansion analysis showed that tandem and segmental duplications contributed to the expansion of the Gmzf_CCCH gene family, and that segmental duplication play the main role. The expression patterns of Gmzf_CCCH genes were tissue-specific. Eleven domesticated genes were detected involved in the regulation of seed oil and protein synthesis as well as growth and development of soybean through GWAS and haplotype analysis for Gmzf_CCCH genes among the 164 of 302 soybeans resequencing data. Among which, 8 genes play an important role in the synthesis of seed oil or fatty acid, and the frequency of their elite haplotypes changes significantly among wild, landrace and improved cultivars, indicating that they have been strongly selected in the process of soybean domestication. Conclusions This study provides a scientific foundation for the comprehensive understanding, future cloning and functional studies of Gmzf_CCCH genes in soybean, meanwhile, it was also helpful for the improvement of soybean with high oil content
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