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ABSTRACT: A novel flame retardant named diethylene N,N',N''‐tri (diethoxy)phosphoramide (DTP) was synthesized using diethyl phosphate and diethylenetriamine via Atherton–Todd reaction. Then, series of flame‐retardant water‐blown rigid polyurethane foams (RPUFs) with expandable graphite (EG) and DTP were prepared through box‐foaming. The results of thermogravimetric analysis showed that DTP/EG changed thermal degradation process of RPUF and promoted enhancing char residues. The complex flame‐retardant system (EG/DTP) endowed RPUF higher limiting oxygen index (LOI) values (29.1%–30.2%) and lower heat release rate peak (PHRR) values according to LOI and microscale combustion calorimeter tests. More importantly, the synergistic flame‐retardant effect between EG and DTP in RPUF was proved by the analysis of synergistic effectivity values. Based on the analysis of cone calorimetric tests, EG/DTP revealed remarkable effects to inhibit the fire intensity and smoke release of RPUF with decreased PHRR and total smoke production due to good char‐forming action. To further investigate the char‐residues of the foams after combustion, scanning electron microscope and energy dispersive X‐ray spectroscopy analyses were conducted. The results suggested that EG/DTP flame‐retardant system promoted RPUF forming a compact, continuous and phosphorus‐rich char layer as a good fire barrier in combustion. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46434. [ABSTRACT FROM AUTHOR]

Abstract: The effect of preroasting on the preoxidation and sodium roasting of vanadium in high‐carbon stone coal was investigated through the study of the change of the phase and valence distribution of vanadium. The result indicated that the ore should be subject to high‐temperature preroasting treatment of approximately 800 °C for a certain time before sodium roasting to achieve a higher oxidation ratio of vanadium. During preroasting at 600 °C, the oxidation of the reducing component completed substantially, and the removal of hydroxyl in mica occurred. After preroasting at 800 °C, the reaction of hydroxyl removal of mica completed, and vanadium oxidation was not hindered. Preroasting at temperatures below 800 °C could only oxidize the V4+ of mica surface and could not oxidize the V3+ presented in the mica lattice, resulting in a small amount of V5+ appearing in the preroasted slag. The stage of carbon removal was controlled by chemical reaction and was mainly affected by temperature. When the preroasting temperature was reduced to below 600 °C, the oxidation time of carbon was found to be prolonged. The temperature was not sufficient to expand the spacing of the mica laminated structure, making it difficult to create favorable conditions for the oxidation of vanadium during the sodium roasting process. [ABSTRACT FROM AUTHOR]

Closed-form expressions for the optimized number and size of repeaters in multi-walled carbon nanotube (MWCNT) interconnects are presented. The contact resistance and inductive effects are taken into account. It is found that the propagation delay of MWCNT interconnects can be reduced effectively by inserting repeaters. However, the contact resistance has a significant influence on the optimized number and size of repeaters. Moreover, it is found that both the optimal number of repeaters and the minimum propagation delay are kept almost unchanged with the variation of carbon nanotube (CNT) kinetic inductance. The optimal number of repeaters in the MWCNT interconnect is much smaller than that in its Cu counterpart, thus saving chip area and power consumption. [ABSTRACT FROM AUTHOR]

The influence of rotational isomerism on the two-photon absorption (TPA) of FTC chromophores has been investigated using the quadratic response theory with the B3LYP functional. Eight rotamers induced by three rotatable single bonds in the molecule are fully optimized, and it is found that their conformational energies are nearly degenerate. Our calculations demonstrate that rotational isomerism has an important effect on the TPA cross sections. For a certain rotamer, the maximum TPA cross section is enhanced significantly. In addition, in the longer wavelength region, the rotational isomerism could lead to a large shift of the TPA position. [ABSTRACT FROM AUTHOR]

A comparative study on the repeater insertion designs in horizontal and vertical graphene nanoribbon (GNR) interconnects is presented. The optimal numbers and sizes of repeaters are calculated by using the particle swarm optimization algorithm, and then the results are employed to train back‐propagation neural networks. By virtue of the trained neural networks, the optimal repeater designs can be quickly conducted for the GNR interconnects. The proposed optimal repeater design approach is more flexible and more adaptive than conventional analytical methods. By utilizing the proposed approach, it is found that the vertical GNR interconnects need less repeaters yet result in better performance than their horizontal counterparts. [ABSTRACT FROM AUTHOR]

A novel functionalized graphene oxide (f‐GO) decorated with phosphorus/nitrogen (P/N)‐containing molecules is fabricated using a facile water‐based procedure. The chemical structure and micro‐morphology are well characterized by a combination of experimental and theoretical methods. Reactive force field‐based molecular dynamics simulations reveal at the atomic level that the GO sheets are successfully functionalized with P‐N flame‐retardant molecules by means of hydrogen bonds. Subsequently, f‐GO with extremely low loading is introduced into epoxy resin (EP) for reducing its flammability. Thermogravimetric analysis suggests that f‐GO significantly reduces the maximum mass loss rate of EP and enhances the char‐yield during heating. Combined with the results of a microscale combustion calorimeter and limiting oxygen index, EP/f‐GO2 shows better flame retardancy than the other nanocomposites. Furthermore, the presence of 2 wt% f‐GO substantially reduces the fire hazard of EP, resulting in 29.3% decline in the peak heat release rate, as well as 73% and 65% reduction in total smoke production and rate of smoke release, respectively, according to cone calorimetric tests. Based on the analyses of the char layers, f‐GO is determined to promote the formation of a more protective phosphorus‐containing char barrier for EP during combustion, indicating an effective condensed phase flame‐retardant mechanism. [ABSTRACT FROM AUTHOR]

Mina53 is a direct novel target protein of Myc. The present study investigated the expression of mina53 and c-myc in gastric carcinoma and the relationship between Mina53 expression and clinicopathological features. The expression levels of mina53 and c-myc mRNA and protein in gastric cancers and the adjacent normal tissues from 12 patients were assessed by laser-capture microdissection (LCM) combined with quantitative polymerase chain reaction (qPCR) and western blotting, respectively. Immunohistochemical analysis was used to evaluate the expression of the Mina53 protein in normal gastric tissues (n=30), chronic atrophic gastritis without intestinal metaplasia (n=44), intestinal metaplasia (n=34), gastric dysplasia (n=36), intestinal-type gastric carcinoma (IGC) (n=30) and diffuse-type gastric carcinoma (DGC) (n=34). The correlation between expression of mina53 and patient survival time was also investigated. The expression levels of mina53 and c-myc mRNA in the gastric carcinomas were found to be higher when compared to these levels in the adjacent normal tissues. In addition, the expression levels of Mina53 and c-Myc protein in gastric carcinomas were higher when compared with levels in the adjacent normal epithelium. mina53 expression was significantly increased during gastric carcinogenesis and was correlated with different clinicopathological factors in IGC and DGC. The prognosis of patients with low expression of Mina53 was more favorable when compared to the prognosis of patients with high expression of Mina53. mina53 expression was gradually elevated during gastric carcinogenesis, and the overexpression of mina53 was correlated with different clinicopathological features between DGC and IGC cases. Furthermore, the prognosis of gastric carcinoma patients was significantly correlated with the expression of Mina53.

One- and two-photon absorption properties of organic chromophores consisting of interacting dipolar branches have been studied using density functional response theory in combination with molecular dynamics simulation. Effects of dipole interaction on optical absorptions have been examined. The importance of solvent effects on optical properties of charge-transfer states is explored by means of polarizable continuum model. It is found that for the interacting dipolar molecule with flexible conformations in solutions, the structural fluctuations can result in new spectral features or significant broadening of one-photon absorption spectrum. Our study highlights again the usefulness of the combined quantum chemical and molecular dynamics approach for modeling two-photon absorption materials in solutions.