查看更多>>摘要：Sb/Yb co-doped SnO2 film was deposited on the glass with sol-gel to prepare high thermal insulation film with high visible transmittance. Its crystal structure is consistent with that of SnO2. Its sheet resistance first decreases then increases with Yb doping content, gets the minimum at 9.0 mol%, reduced about an order of magnitude compared with Sb doped film. Its visible average transmittance (380-780 nm) fluctuates a bit, gets the minimum 79.0% at 9.0 mol%, the maximum 84.1% at 6.0 mol%. Its average near-infrared transmittance (780-2500 nm) gets the minimum 27.9% at 9.0 mol%, decreases 70.2% compared with the glass.
查看更多>>摘要：The complex nature of methanolysis of urea with the formation of O-methylcarbamate was studied using B3LYP/6-311++G(df,p) and M06/6-311++G(df,p) density functional methods. The first stage of the reaction, the decomposition of urea to isocyanic acid and ammonia, proceeds with catalysis by alcohol molecules. In the second stage, the interaction of isocyanic acid with methanol with the formation of O-methyl carbamate, the methanol monomer exhibits low activity. The methanol dimer is significantly more active. The main route for the formation of O-methyl carbamate is the reaction of isocyanic acid with methanol catalyzed by the carbamate itself.
查看更多>>摘要：This work reports the preparation of polycrystalline titanium dioxide (TiO2) thin films using spray pyrolysis technique at various temperatures to access their photoelectrocatalytic (PEC) performance. The films were characterized by photocurrent response measurements, X-ray diffraction, Scanning electron microscopy, Elemental analysis, Fourier-transform Raman spectroscopy and UV-vis spectroscopy. The TiO2 showed heterogeneous photocatalytic potential against the oxidative degradation of Phthalic acid (PA) and Benzoic acid (BA) which were used as model pollutants. The PEC behavior of the typical TiO2 film was excellent for oxidative degradation of both pollutants under UV irradiation.
查看更多>>摘要：Herein, we report a removing resonance fluorescence (RRF) technique for light scattering spectroscopy (RLS), which takes full advantage of the differences between resonance fluorescence (RF) and scattered light in different wavelength regions to achieve an accurate separation of them. Then MPA-capped quantum dots (QDs) sensing Hg2+ is employed as an example to introduce the implementation of this method. The results indicate that Hg2+ ions destroy the stability of QDs, causing them to agglomerate, which might contribute to fluorescence quenching of QDs. Our study provides a useful tool for separating RF and scattered spectra, which expands the application range of RLS.
查看更多>>摘要：A backflow (BF) transformation was applied to a vibrational self-consistent field wavefunction, which is the mean-field approximation in an anharmonic vibrational structure theory. We tested its effectiveness on the H2O molecule using quantum Monte Carlo method. Each normal mode coordinate was transformed into collective coordinates using the correlation function depending on whole coordinates. The vibrational frequencies with the BF transformation reasonably agree with the vibrational configuration interaction (VCI) results. The vibrational probability density to which the BF transformation was applied was also consistent with the VCI results and showed that the BF transformation appropriately take into account the inter-mode couplings.
查看更多>>摘要：Young's modulus and friction force of the gecko-inspired materials are important parameters for the applications of climbing robots and devices. Increasing the friction force of polymer composite pillar with desirable Young's modulus is current research focus to expand the potential applications of bio-inspired materials. Also, the stability of inspired pillar under radiated exposure is essential to be investigated to explore the irradiation effect on patterned composite array. Here the boron nitride nanosheets (BNNSs) have been exfoliated with assistance of hyperbranched polyethylene (HBPE) as polymer stabilizer via CH-pi non-covalent interaction. The nanosheets were incorporated into polydimethylsiloxane (PDMS) mixture that was then utilized to prepare composite pillar via plasma etched silicon template. The electron irradiation was conducted to examine the morphology of patterned array and the mechanical property of PDMS composite. The coefficient of friction for PMDS composite decreases slightly after irradiation, and it retains high value around 1.2 for 0.2 wt% composite pillar with comparison to 1.3 for PDMS. The stress for irradiated PDMS decreases from 3.1 MPa to 1.8 MPa with the strain of 281% at accumulating dose of 5 x 10(15) rad. During irradiation, the doubling terminating reaction is probably induced by the active radical sites in elastomer. The PDMS pillar exhibits large friction coefficient and high mechanical property due to new crosslinking network of elastomer during irradiation. This work develops polymer composite with pillar architecture by silicon template method, and sheds a light on the electron irradiation effect of composite pillar to pave the path for the application of gecko-inspired material in spacecraft.
查看更多>>摘要：We propose a guided self-assembly process to produce atomically precise arrays of single dopant atoms in lieu of lithographic patterning for quantum computing applications. We investigate molecular precursor adsorption into self-assembled single-dimer window (SDW) adsorption sites formed on Si(100) with density functional theory (DFT). Several relevant dopant precursor (PH3, BCl3, AlCl3, GaCl3) and resist (H, Cl, Br, I) combinations are explored. PH3 adsorbed without barrier on all resists studied, while BCl3 exhibited the largest adsorption barrier, 0.34 eV, with an I resist. Dense arrays of AlCl3 formed within experimentally realizable conditions demonstrating the potential impact of this approach.
del Rosario Rodriguez-Hidalgo, MariaSoto-Figueroa, CesarGalicia-Garcia, TomasRuiz-Santos, Rosalia...
8页
查看更多>>摘要：Micellar phase control of thermoresponsive polymeric micelles (PAA-co-PAN) via upper critical solution temperature (UCST) in aqueous environment was explored using DPD simulations. Performing a thermal scan we show that above its UCST a stable micellar system is generated. When the temperature decreases below the UCST (304 K), the colloidal system becomes thermodynamically unstable generating hydrophobic particles with PAN core and PAA-shell. A notable effect is the generation of a cloud point and this polymeric multiphase behaviour is used to show the removal of methylene-blue dye from a solution. The stages of the removal process via cloud point are shown in detail.
查看更多>>摘要：Rate coefficients for reactions of H2SO4 with OH, O(P-3) and Cl radicals over 160-298 K were estimated computationally. We propose k(OH) = 8.5 x 10(-14) exp(-50 K/T), k(O) = 1.1 x 10(-12) exp(-5012 K/T) and k(Cl) = 3.1 x 10(-9) exp(-3314 K/T) cm(3) molecule(-1) s(-1). One product of the H-atom abstraction reactions, and likely from reaction of H2SO4 with O(D-1) too, is the HOSO3 radical which may also be formed via OH + SO3 addition, with k(0)(N-2) = 7.3 x 10(-30) (T/298K)(-2.64) cm(6) molecule(-2) s(-1) and k(infinity) = 4.7 x 10(-10) (T/298 K)(0.167) cm(3) molecule(-1) s(-1).
Khan, Sami UllahRaza, AliAl-Khaled, KamelKhan, M. Ijaz...
7页
查看更多>>摘要：This investigation deals with comparative thermal aspect of nanofluid with kerosene oil and water base fluid subject to the inclined magnetic force. The inclined surface induced the flow. The Newtonian heating with nonlinear relations are also focused to modify the analysis. The fractional model of non-dimensional leading equations is formulated by utilizing a recent definition of fractional derivative technique namely AtanganaBaleanu (AB) time fractional derivative. The semi-analytical solution of energy and momentum profile is described by utilizing the mathematical technique Laplace transform and different numerical algorithms are utilized for the inverse of Laplace i.e. Stehfest and Tzou's schemes via MATLAB computational software. The behavior of different parameters with changed values is analyzed and plotted graphically for energy and momentum profiles. The comparative thermal analysis for the kerosene oil and water base material is presented. It is observed the enhancement in heat transfer is comparatively higher for the water-based nanofluid as compared to kerosene oil-based nanofluid. The change is velocity is more progressive for the viscous case as compared to the Casson fluid. Moreover, the rate of velocity is larger for the ordinary derivative model as compared to fractional model derivative.
NSTL
Elsevier