539 research outputs found
Reliability Analysis of a Repairable C (2, 3; G ) System with Repair Priority and one is"as good as new"
In this paper, we discuss a repairable linear C (2, 3; G) system. One repairman carries out the maintenance of the system. It is assumed that the working time and the repair time of each component in the system are both exponentially distributed and only one component after repair is as good as new. Each component is classified as either a key component or an ordinary one according to its priority role to the system’s repair. We apply the geometric process, supplementary variable technique and generalized Markov process to study a repairable linear C (2, 3; G) system. We obtain Laplace transforms of some reliability indices such as availability and reliability.Key words: repairable system; generalized Markov process; key component; geometric proces
Finite element method for obtaining the regularized photon Green function in lossy material
Photon Green function (GF) is the vital and most decisive factor in the field
of quantum light-matter interaction. It is divergent with two equal space
arguments in arbitrary-shaped lossy structure and should be regularized. We
introduce a finite element method for calculating the regularized GF. It is
expressed by the averaged radiation electric field over the finite-size of the
photon emitter. For emitter located in homogeneous lossy material, excellent
agreement with the analytical results is found for both real cavity model and
virtual cavity model. For emitter located in a metal nano-sphere, the
regularized scattered GF, which is the difference between the regularized GF
and the analytical regularized one in homogeneous space, agrees well with the
analytical scattered GF
Quantum chemical calculation study on the thermal decomposition of electrolyte during lithium-ion battery thermal runaway
Understanding the behavior of lithium-ion battery electrolytes during thermal runaway is essential for designing safer batteries. However, current reports on electrolyte decomposition behaviors often focus on reactions with electrode materials. Herein we use quantum chemical calculations to develop a model for the thermal decomposition mechanism of electrolytes under both electrolyte and ambient atmosphere conditions. The thermal stability is found to be associated with the dielectric constants of electrolyte constituents. Within the electrolyte, the solvation effects between molecules increase electrolyte stability, making thermal decomposition a more difficult process. Furthermore, Li+ is observed to facilitate electrolyte thermal decomposition, as the energy required for the thermal decomposition reactions of molecules decreases when they are bonded with Li+. It is hoped that this study will offer a theoretical basis for understanding the complex reactions occurring during thermal runaway events
Effects of vitamin C on inhalation anesthetic isoflurane-induced developmental, neuronal apoptosis in neonatal rats
Developmental abnormalities, neuronal apoptosis and associated cognitive impairment following isoflurane exposure in neonatal rodents have been reported. The study was undertaken to investigate the effect of vitamin C supplementation against isoflurane-induced neurotoxicity. Seven day old rats were exposed to 1.1% isoflurane, or air for 6 hours. Treatment groups were administered with vitamin C (30 mg/kg, orally) from postnatal day 1 (P1) to P10 and were exposed to isoflurane on P7. Isoflurane exposure induced apoptosis was determined by Fluoro-Jade C and terminal deoxynucleotidyl-transferase-mediated 2-deoxyuridine 5-triphosphate nick-end labeling assay. Vitamin C considerably improved memory and learning impairments, modulated neuroapoptosis and improved expressions of brain-derived neurotrophic factor, nerve growth factor, Bcl-xL and decreased activated caspase-3 expressions. Thus, vitamin C effectively offered protection against isoflurane-induced neuronal apoptosis, learning and memory disturbances
μ3-DodecaÂtungsto(V,VI)aluminato-κ3 O:O′:O′′-trisÂ[aquaÂbisÂ(ethylÂeneÂdiamine-κ2 N,N′)copper(II)]
The title compound, [AlCu3W12O40(C2H8N2)6(H2O)3], was prepared under hydroÂthermal conditions. The Cu2+ ion displays an elongated octaÂhedral geometry defined by one bridging O atom from the polyoxidoanion and a coordinated water molÂecule in axial positions and four N atoms of the two chelating ethylÂenediamine (en) ligands in equatorial positions. The one-electron reduced [AlW12O40]6− anion coordinates three [Cu(en)(H2O)]2+ fragments, generating a neutral tri-supported Keggin-type polyoxidometalate (POM). This tri-supported POM is located in a special position of symmetry and therefore O atoms from the central AlO4 tetraÂhedron are disordered over two sets of sites. Disorder is also observed for three other bridging O atoms of the POM. In the crystal, molÂecules are connected via N—H⋯O and O—H⋯O hydrogen bonds, forming a three-dimensional framework
Effects of vitamin C on inhalation anesthetic isoflurane-induced developmental, neuronal apoptosis in neonatal rats
Chemical Profiling and Comparison of Sangju Ganmao Tablet and Its Component Herbs Using Two-Dimensional Liquid Chromatography to Explore Compatibility Mechanism of Herbs
Sangju Ganmao tablet (SGT), a well-known Chinese patent medicine used to treat cold symptoms, is made from eight herbal medicines. In this study, an off-line hydrophilic interaction × reversed-phase two-dimensional liquid chromatography (HILIC × RP 2D-LC) method was developed to comprehensively separate the chemical constituents of SGT. Through optimization of the experimental conditions, a total of 465 peaks were finally detected in SGT, and the structures of 54 selected compounds were fully identified or tentatively characterized by quadrupole time-of-flight mass spectrometry (qTOF-MS) analysis. The established 2D-LC analysis showed high orthogonality (63.62%) and approximate 11-fold improvement in peak capacity (2399 and 1099, obtained by two calculation methods), in contrast to conventional one-dimensional RPLC separation. The eight component herbs of SGT were also respectively separated by using the 2D-LC system, and we found that a total of 12 peaks detected in SGT were not discovered in any component herbs. These newly generated chemical constituents would benefit better understanding of the compatibility mechanism of the component herbs. The strategy established in this study could be used for systematic chemical comparison of SGT and its component herbs, which contributes to exploration of herbal compatibility mechanism
Graphene-based fabrics and their applications: a review
[EN] Graphene has emerged as a revolutionary material in different fields of science and engineering due to its extraordinary properties such as: high electron mobility, high thermal conductivity, mechanical properties, easy functionalization, etc. The field of textiles is continuously integrating new materials to provide fabrics with new functionalities, hence its incorporation on fabrics was a logical step. Its application to the field of textiles has been recently reported, which has allowed the development of textiles with different functionalities such as: antistatic, UV-protecting, electroconductive, photocatalytic, antibacterial, thermal conductivity, energy storage in flexible supercapacitors, electrodes for batteries, sensors, etc. Up to date no review has been written regarding graphene-based fabrics and their applications. The present review aims to fill the existing gap and provide perspectives into the preparation and applications of graphene-based fabrics and yarns.J. Molina wishes to thank to the Spanish Ministerio de Ciencia e Innovacion (contract CTM2011-23583) for the financial support. J. Molina is grateful to the Conselleria d'Educacio, Formacio i Ocupacio (Generalitat Valenciana) for the Programa VALi + D Postdoctoral Fellowship (APOSTD/2013/056).Molina Puerto, J. (2016). Graphene-based fabrics and their applications: a review. RSC Advances. 6:68261-68291. https://doi.org/10.1039/c6ra12365aS6826168291
Krüppel-Like Factor 8 Is a New Wnt/Beta-Catenin Signaling Target Gene and Regulator in Hepatocellular Carcinoma
Krüppel-like factor 8 (KLF8) plays important role in cell cycle and oncogenic transformation. Here we report the mechanisms by which KLF8 crosstalks with Wnt/β-catenin signaling pathway and regulates hepatocellular carcinoma (HCC) cells proliferation. We show that overexpression of KLF8 and nucleus accumulation of β-catenin in the human HCC samples are positively correlated. More importantly, KLF8 protein levels plus nucleus accumulation of β-catenin levels were significantly elevated in high-grade HCC compared to low-grade HCC. Using HCC HepG2 cells we find that, on the one hand both protein and mRNA of KLF8 are up-regulated under Wnt3a stimulation, on the other hand overexpression of KLF8 increases the cytoplasm and nucleus accumulation of β-catenin, recruits p300 to β-catenin/T-cell factor 4 (TCF4) transcription complex, enhances TOP flash report gene transcription, and induces Wnt/β-catenin signaling target genes c-Myc, cyclin D1 and Axin1 expression. Knockdown of KLF8 using shRNA inhibits Wnt3a induced transcription of TOP flash report gene and expression of c-Myc, cyclin D1 and Axin1. Knockdown of β-catenin by shRNA rescues the enhanced HepG2 and Hep3B cells proliferation ability induced by overexpression of KLF8
- …