Nb-gateway for hydrogen desorption in Nb2O5 catalyzed MgH2 nanocomposite

The state of Nb-contained catalysts in MgH2 nanocomposites was investigated during the full cycle. X-ray diffraction (XRD) results showed that Nb2O5 and Nb reacted with MgH2 during ball-milling, forming NbH2 and NbH, respectively. In the following dehydrogenation, the (di)hydride decomposed, and Nb was produced. Then NbH was generated in both samples after rehydrogenation. Similar composition in both samples suggests that the catalytic effect follows the same mechanism, the Nb-gateway model, in which Nb facilitates the hydrogen transportation from MgH2 to the outside. By contrast, NbO remained during the full cycle. Scanning and transmission electron microscopy (SEM and TEM) observations revealed that the Nb2O5-doped sample tended to be refined in size, compared to the Nb-doped and NbO-doped ones. Nb crystals in the Nb 2O5-doped sample were observed to be highly dispersed in the sample, with 10-20 nm in size. Given all that, tiny Nb crystals distributed in the composites worked as the gateway facilitating hydrogen transportation and improving dehydrogenation properties

Nb-Gateway for Hydrogen Desorption in Nb₂O₅ Catalyzed MgH₂ Nanocomposite

The state of Nb-contained catalysts in MgH₂ nanocomposites was investigated during the full cycle. X-ray diffraction (XRD) results showed that Nb₂O₅ and Nb reacted with MgH₂ during ball-milling, forming NbH₂ and NbH, respectively. In the following dehydrogenation, the (di)­hydride decomposed, and Nb was produced. Then NbH was generated in both samples after rehydrogenation. Similar composition in both samples suggests that the catalytic effect follows the same mechanism, the Nb-gateway model, in which Nb facilitates the hydrogen transportation from MgH₂ to the outside. By contrast, NbO remained during the full cycle. Scanning and transmission electron microscopy (SEM and TEM) observations revealed that the Nb₂O₅-doped sample tended to be refined in size, compared to the Nb-doped and NbO-doped ones. Nb crystals in the Nb₂O₅-doped sample were observed to be highly dispersed in the sample, with 10–20 nm in size. Given all that, tiny Nb crystals distributed in the composites worked as the gateway facilitating hydrogen transportation and improving dehydrogenation properties

Extensive Microsatellite Variation in Rice Induced by Introgression from Wild Rice (<i>Zizania latifolia</i> Griseb.)

<div><p>Background</p><p>It is widely accepted that interspecific hybridization may induce genomic instability in the resultant hybrids. However, few studies have been performed on the genomic analysis of homoploid hybrids and introgression lines. We have reported previously that by introgressive hybridization, a set of introgression lines between rice (<i>Oryza sativa</i> L.) and wild rice (<i>Zizania latifolia</i> Griseb.) was successfully generated, and which have led to the release of several cultivars.</p><p>Methodology</p><p>Using 96 microsatellite markers located in the nuclear and organelle genomes of rice, we investigated microsatellite stability in three typical introgression lines. Expression of a set of mismatch repair (MMR) genes and microsatellite-containing genes was also analyzed.</p><p>Results/Conclusions</p><p>Compared with the recipient rice cultivar (Matsumae), 55 of the 96 microsatellite loci revealed variation in one or more of the introgression lines, and 58.2% of the altered alleles were shared by at least two lines, indicating that most of the alterations had occurred in the early stages of introgression before their further differentiation. 73.9% of the non-shared variations were detected only in one introgression line, i.e. RZ2. Sequence alignment showed that the variations included substitutions and indels that occurred both within the repeat tracts and in the flanking regions. Interestingly, expression of a set of MMR genes altered dramatically in the introgression lines relative to their rice parent, suggesting participation of the MMR system in the generation of microsatellite variants. Some of the altered microsatellite loci are concordant with changed expression of the genes harboring them, suggesting their possible <i>cis</i>-regulatory roles in controlling gene expression. Because these genes bear meaningful homology to known-functional proteins, we conclude that the introgression-induced extensive variation of microsatellites may have contributed to the novel phenotypes in the introgression lines.</p></div

Comparison of microsatellite variation in the repeat tracts and the flanking regions in the introgression lines at the nucleotide sequence level.

a<p>Both nuclear and organellar genomic microsatellite markers were combined together and classified into four categories (C1 to C4) depending on their location relative genes.</p

Evaluation of the relative transcript levels of the eight MMR genes in Matsumae, RZ1, RZ2 and RZ35, by quantitative RT-PCR.

<p>Total RNA samples were prepared from the leaves at three-leaf stage, and were used for cDNA synthesis and the subsequent quantitative PCR with gene specific primers. Each data point was calculated with the results of three technical repeats.</p

Effect of Lithium Ion Conduction on Hydrogen Desorption of LiNH₂–LiH Solid Composite

This paper presents a relationship between ionic mobility and reaction kinetics for the Li–N–H system after doping LiTi₂O₄. The structural characteristic of this fast ionic conductor was introduced to the complex–hydride system. On one hand, the properties of the dehydrogenation process were improved significantly. On the other hand, the relationship between lithium ionic conductivity and the catalytic effect on the dehydrogenation was investigated according to the alternating current (AC) impedance results. The lithium ionic conductivity of samples with catalyst was higher than the samples without catalyst. Especially, the conductivity of LiNH₂ and LiH mixtures with LiTi₂O₄ was almost 1.5 times higher than that of LiNH₂ and LiH. The mobility of the Li⁺ ions between LiH and LiNH₂ solid phases was enhanced by adding LiTi₂O₄

Microsatellite Variation patterns in the introgression lines.

*<p>Indictes the variations happened only in RZ2.</p

Evaluation of the relative transcript levels of the three microsatellite possibly regulated genes in Matsumae, RZ1, RZ2 and RZ35, by quantitative RT-PCR.

<p>(<b>A</b>) Transcript levels of <i>Os07g46750</i>; (<b>B</b>) Transcript levels of <i>Os05g35200</i>; (<b>C</b>) Transcript levels of <i>Os02g15594</i>.</p