Effects of carbon nanotubes additions on flash ignition characteristics of Fe and Al nanoparticles

<p>The influences of carbon nanotubes (CNTs) additions on the flash ignition characteristics of Iron (Fe) and aluminum (Al) nanoparticles (NPs) were presented. CNTs can be used as the additive to these metal nanoparticles for improving the flash ignition and burning processes. Different mass fractions of CNTs additions were considered. The mixture of Al and CNTs could combust in air with obvious giant flame, whereas the mixture of Fe and CNTs combusted under a relative stable condition with slight red light. The temperature distributions were measured using non-contact optical method and showed that Al NPs mixed with CNTs were burning at a higher temperature level than Fe NPs. Although different mass fractions of CNTs cannot significantly change the overall flash ignition phenomenon, CNTs additions influenced the minimum ignition energy (MIE) of mixtures. The appropriate content of CNTs addition can decrease the Fe NPs MIE significantly. However, the Al NPs MIE decreased all along with the increase of CNTs content. The micro- and nano- structures of Fe and Al NPs with CNTs additions before and after ignitions were examined by scanning electron microscope and high-resolution transmission electron microscopy. It was found that the special thermal conductive characteristics of CNTs and the cross-connected features for metal particles with CNTs caused the enhancement of flash ignition.</p

Synthesis and Self-Assembly of Amphiphilic Janus Laponite Disks

Materials with asymmetric structures are attractive for wide applications in chemistry and materials science. Two-dimensional Janus disks or nanosheets are particularly appealing because of the unique shape and the distinctive self-assembled structures. A facile and versatile method for the synthesis of amphiphilic Janus Laponite disks is proposed in this paper. Positively charged PS spheres were prepared by ATRP emulsion polymerization. Upon addition of aqueous dispersion of negatively charged Laponite disks into PS emulsions, the nanosized disks were adsorbed onto the surface of PS particles via electrostatic interaction. One side of a Laponite disk touches the surface of a colloidal particle, and the other side faces the medium. After addition of positively charged polymeric micelles or quaternized poly­(2-(dimethylamino)­ethyl methacrylate) (q-PDMAEMA) chains into the aqueous dispersions of the colloidal particles, the micelles or polymer chains were immobilized onto the Laponite disks, and Janus disks were produced on particle templates. After centrifugation and redispersion of the colloidal particles into a good solvent, amphiphilic Janus Laponite disks with PS chains on one side and hydrophilic q-PDMAEMA or polymeric micelles on the other side were obtained. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used to characterize the Janus disks. Self-assembly of the Janus disks at liquid–liquid interface and in selective solvents was investigated. Similar to small molecular surfactants, the amphiphilic Janus disks can self-assemble at liquid–liquid interface, resulting in a decrease of the interfacial tension and emulsification of oil droplets in water. In a THF–methanol mixture at a volume ratio of 1:6, PS brushes on the Janus disks collapse forming two-layer face-to-face stacks. The distinctive self-assembled structures were analyzed by TEM and AFM

Rapid SNP Discovery and a RAD-Based High-Density Linkage Map in Jujube (<i>Ziziphus</i> Mill.)

<div><p>Background</p><p><i>Ziziphus</i> Mill. (jujube), the most valued genus of Rhamnaceae, comprises of a number of economically and ecologically important species such as <i>Z. jujuba</i> Mill., <i>Z. acidojujuba</i> Cheng et Liu and <i>Z. mauritiana</i> Lam. Single nucleotide polymorphism (SNP) markers and a high-density genetic map are of great benefit to the improvement of the crop, mapping quantitative trait loci (QTL) and analyzing genome structure. However, such a high-density map is still absent in the genus <i>Ziziphus</i> and even the family Rhamnaceae. The recently developed restriction-site associated DNA (RAD) marker has been proven to be most powerful in genetic map construction. The objective of this study was to construct a high-density linkage map using the RAD tags generated by next generation sequencing.</p><p>Results</p><p>An interspecific F1 population and their parents (<i>Z. jujuba</i> Mill. ‘JMS2’ × <i>Z. acidojujuba</i> Cheng et Liu ‘Xing 16’) were genotyped using a mapping-by-sequencing approach, to generate RAD-based SNP markers. A total of 42,784 putative high quality SNPs were identified between the parents and 2,872 high-quality RAD markers were grouped in genetic maps. Of the 2,872 RAD markers, 1,307 were linked to the female genetic map, 1,336 to the male map, and 2,748 to the integrated map spanning 913.87 centi-morgans (cM) with an average marker interval of 0.34 cM. The integrated map contained 12 linkage groups (LGs), consistent with the haploid chromosome number of the two parents.</p><p>Conclusion</p><p>We first generated a high-density genetic linkage map with 2,748 RAD markers for jujube and a large number of SNPs were also developed. It provides a useful tool for both marker-assisted breeding and a variety of genome investigations in jujube, such as sequence assembly, gene localization, QTL detection and genome structure comparison.</p></div

RAD paired-end contig assembly of the parents.

<p>RAD paired-end contig assembly of the parents.</p

The statistics of reads, tags and stacks in 107 F1 plant accessions.

<p>(a) The number of tags and reads of the F1 population; (b) The mean depth of stacks in each individual.The ID 1 and 2 are the P1 (Female parent) and P2 (Male parent) respectively.</p

RAD tag and SNP discovery in the parents.

<p>RAD tag and SNP discovery in the parents.</p

Transitions and transversions within 42,784 biallelic single nucleotide polymorphisms (SNPs) detected among jujube parents.

<p>This figure shows all the statistics of transitions and transversions SNPs between the jujube parents.</p

Tunable Ultraviolet Photoresponse in Solution-Processed p–n Junction Photodiodes Based on Transition-Metal Oxides

Solution-processed p–n heterojunction photodiodes have been fabricated based on transition-metal oxides in which NiO and ternary Zn_1–<i>x</i>Mg_<i>x</i>O (<i>x</i> = 0–0.1) have been employed as p-type and n-type semiconductors, respectively. Composition-related structural, electrical, and optical properties are also investigated for all the films. It has been observed that the bandgap of Zn_1–<i>x</i>Mg_<i>x</i>O films can be tuned between 3.24 and 3.49 eV by increasing Mg content. The fabricated highly visible-blind p–n junction photodiodes show an excellent rectification ratio along with good photoresponse and quantum efficiency under ultraviolet (UV) illumination. With an applied reverse bias of 1 V and depending on the value of <i>x</i>, the maximum responsivity of the devices varies between 0.22 and 0.4 A/W and the detectivity varies between 0.17 × 10¹² and 2.2 × 10¹² cm (Hz)^1/2/W. The photodetectors show an excellent UV-to-visible rejection ratio. Compositional nonuniformity has been observed locally in the alloyed films with <i>x</i> = 0.1, which is manifested in photoresponse and X-ray analysis data. This paper demonstrates simple solution-processed, low cost, band tunable photodiodes with excellent figures of merit operated under low bias

A summary of the genetic linkage map constructed in <i>Ziziphus</i> Mill.

<p>A summary of the genetic linkage map constructed in <i>Ziziphus</i> Mill.</p

The linkage maps of LG02 for <i>Z. jujuba</i> (female, left), <i>Z. acidojujuba</i> (male, right) and their integrated map (middle) are shown as an example.

<p>Detailed lists of all the molecular markers, including their genetic distance in each linkage group, are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109850#pone.0109850.s009" target="_blank">Table S4</a>. All 12 LGs are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109850#pone.0109850.s001" target="_blank">Figure S1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109850#pone.0109850.s002" target="_blank">S2</a>, and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109850#pone.0109850.s003" target="_blank">S3</a>.</p