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21.
22.
Wilson PR Roschuk T Dunn K Normand EN Chelomentsev E Zalloum OH Wojcik J Mascher P 《Nanoscale research letters》2011,6(1):168
Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition
and processing parameters have on their growth, luminescent properties, and electronic structure. Luminescence was observed
from Si-ncs formed in silicon-rich silicon nitride films with a broad range of compositions and grown using three different
types of chemical vapour deposition systems. Photoluminescence (PL) experiments revealed broad, tunable emissions with peaks
ranging from the near-infrared across the full visible spectrum. The emission energy was highly dependent on the film composition
and changed only slightly with annealing temperature and time, which primarily affected the emission intensity. The PL spectra
from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and
growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further
increased. X-ray absorption near edge structure at the Si K- and L3,2-edges exhibited composition-dependent phase separation and structural re-ordering of the Si-ncs and silicon nitride host
matrix under different post-deposition annealing conditions and generally supported the trends observed in the PL spectra. 相似文献
23.
24.
Aravindan Rajendran Tyler Fox Bo Hu 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2017,92(7):i-i
The cover image, by Aravindan Rajendran et al., is based on the Research Article Nutrient recovery from ethanol co‐products by a novel mycoalgae biofilm: attached cultures of symbiotic fungi and algae, DOI: 10.1002/jctb.5177 .
25.
Tyler Galpin Ryan T. Chartier Nicholas Levergood 《Aerosol science and technology》2017,51(10):1158-1167
The recent development of an Aerosol Extinction Differential Optical Absorption Spectrometer (AE-DOAS) has allowed for the retrieval of wavelength dependent complex refractive indices for polystyrene latex spheres (PSL). The AE-DOAS is a white-type multi-pass gas cell coupled to a UV-Vis spectrometer. Refractive index values are retrieved for wavelengths between 220 and 420 nm by minimizing the χ2 goodness-of-fit between measured extinction for five diameters of PSL and model Mie Theory predictions. Comparison to literature shows agreement at wavelengths >360 nm demonstrating the validity of this new instrumental approach while expanding the known refractive index range for PSLs further into the UV where it is previously unreported. In the studied wavelength range, coefficients for the general Cauchy dispersion relationship (A = 1.538(11); B = 0.0043(16) μm2; C = 0.00094(5) μm4) for PSLs were determined using the retrieved real portion of the refractive index and the wavelength in microns. In addition, this work indicates that the precision of retrieved values is impacted by the particle diameters chosen for the experiment where retrievals for shorter wavelengths of light benefit from the study of smaller sized particles.
Copyright © 2017 American Association for Aerosol Research 相似文献
26.
ABSTRACT Experimental data on sorption isotherms of alfalfa pellets were used to determine the thermodynamic functions (differential heat of sorption, spreading pressure, net integral enthalpy and entropy) of the pellets. The thermodynamic functions were then utilized in modeling the specific heats of pellets as a function of moisture content. The estimated values of the thermodynamic functions at different moisture contents confirmed the results of an earlier study on the influence of moisture sorption on the physical integrity of the pellets. The changes in the thermodynamic properties and physical integrity were prominent when the moisture of the pellets were between 0.10 and 0.12 (mass fraction basis). Using the differential heat of sorption, it was determined that alfalfa pellets have higher affinity for moisture uptake when compared to wheat and lentils. The specific heat of the solids of alfalfa pellets had a parabolic relationship with moisture whereas the specific heat of water fraction increased linearly with moisture content of the pellets. 相似文献
27.
Dr. Marina Tanasova Matthew Plutschack Megan E. Muroski Prof. Shana J. Sturla Prof. Geoffrey F. Strouse Prof. D. Tyler McQuade 《Chembiochem : a European journal of chemical biology》2013,14(10):1263-1270
Recent publications suggest that high dietary fructose might play a significant role in cancer metabolism and can exacerbate a number of aspects of metabolic syndrome. Addressing the role that fructose plays in human health is a controversial question and requires a detailed understanding of many factors including the mechanism of fructose transport into healthy and diseased cells. Fructose transport into cells is thought to be largely mediated by the passive hexose transporters Glut2 and Glut5. To date, no probes that can be selectively transported by one of these enzymes but not by the other have been identified. The data presented here indicate that, in MCF‐7 cells, a 1‐amino‐2,5‐anhydro‐D ‐mannitol‐based fluorescent NBDM probe is transported twice as efficiently as fructose and that this takes place with the aid of Glut5. Its Glut5 specificity and differential uptake in cancer cells and in normal cells suggest this NBDM probe as a potentially useful tool for cross‐cell‐line correlation of Glut5 transport activity. 相似文献
28.
Christopher S. Dandeneau Tyler W. Bodick Rajendra K. Bordia Fumio S. Ohuchi 《Journal of the American Ceramic Society》2013,96(7):2230-2237
The thermoelectric properties of bulk polycrystalline Sr0.5Ba0.5Nb2O6 (SBN50) fabricated via solution combustion synthesis (SCS) and reduced at temperatures of 900°C–1150°C were explored. The Seebeck coefficient (S) of all samples increased over the entire range of testing temperatures; a peak S value of ?281 μV/K was obtained at 930 K for the sample reduced at 900°C. A metal‐insulator transition was observed in the electrical conductivity (σ) of samples reduced at 1000°C–1150°C, whereas only semiconducting electrical behavior was observed for the sample reduced at 900°C. An optimal balance between S and σ was achieved for the pellet reduced at 1000°C, which exhibited a maximum power factor of 1.78 μW/cm·K2 at 930 K. Over a temperature range of 300–930 K, the thermal conductivity (κ) of as‐processed and reduced (1000°C) SBN50 was found to be 1.03–1.4 and 1.46–1.84 W/m·K, respectively. A maximum figure of merit (ZT) of 0.09 was obtained at 930 K for the 1000°C‐reduced sample. X‐ray photoelectron spectroscopy revealed that the Nb2+ peak intensity increased at higher reduction temperatures, which could possibly lead to a distortion of NbO6 octahedra and a decrease in the Seebeck coefficient. 相似文献
29.
Sarah E. Brady David R. Tyler 《Journal of Inorganic and Organometallic Polymers and Materials》2013,23(1):158-166
The [(η5-C5H4(CH2)3N3)Mo(CO)3]2 dimer (3) was prepared and used to determine if the Huisgen cycloaddition reaction could be used to synthesize high molecular weight star polymers with metal–metal bonds in the arms. Several different click catalysts were examined. Cp*Ru(PPh3)2Cl (Cp* = η5-C5(CH3)5) was previously shown to catalyze the formation of metal–metal bond-containing polymers using click chemistry; however, this catalyst underwent a Staudinger reaction with dimer 3 when a model coupling reaction was attempted with phenylacetylene. In order to avoid the Staudinger reaction, Cp*Ru(COD)Cl was used as the catalyst in the reaction of 3 with phenylacetylene, and coupling was observed after 14 h. Synthesis of a star polymer was attempted with 3 and 1,3,5-triethynylbenzene. Instead of coupling, Cp*Ru(COD)Cl reacted with the 1,3,5-triethynylbenzene. A third catalyst, Cu(IMes)Cl (IMes = 1,3-dimesityl-imidazol-2-ylidene) was used to couple 3 with 1,3,5-triethynylbenzene in 48 h. Both a high molecular weight polymer (M n = 77,000 g mol?1) and a tripodal star core (M n = 1,800 g mol?1) were successfully prepared with this catalyst. 相似文献
30.
Loren C. Brown Tyler J. Richardson Clair F. Lusk Nickolaus K. Weise Matthew Laskoski 《应用聚合物科学杂志》2024,141(11):e55080
A promising high temperature phthalonitrile (PN) resin composed of a polyetherketoneketone (PEKK) core bridged by two bisphenol A linkers and end capped with PN groups is presented. This PEKK-PN resin was characterized via differential scanning calorimetry, thermogravimetric analysis, proton nuclear magnetic resonance spectroscopy, scanning electron microscopy, dynamic mechanical analysis, attenuated total reflection Fourier transform infrared, and rheometry. The PEKK-PN resin was evaluated with two different compositions containing 1) 70:30 PEKK-PN to bisphenol A PN (n = 0) and 2) pure PEKK-PN. The 70:30 PEKK-PN resin was mixed with bis[4-(3-aminophenoxy)phenyl]sulfone and exhibited a melt viscosity of 271 cP, much lower than the 657 cP viscosity of the pure PEKK-PN mixture. Void-free PEKK-PN polymers were easily prepared by degassing and curing up to 380°C, resulting in fully crosslinked networks exhibiting thermal stability above 500°C and a 75% char yield. Additionally, the cured PEKK-PN polymer samples displayed good mechanical integrity retaining 50% stiffness at 300°C. This combination of properties suggests these new PEKK-PN resins are excellent materials for high temperature thermosets in composite applications. 相似文献