Mischke P, Dai H. Economic Impacts of Future Changes in the Energy System—Global Perspectives. In: Glynn J, Fortes P, Krook-Riekkola A, Labriet M, Vielle M, Kypreos S, Lehtilä A, Mischke P, Dai H, Gargiulo M Informing Energy and Climate Policies Using Energy Systems Models. Springer International Publishing; 2015. pp. 333-358.
Mischke P, Dai H. Economic Impacts of Future Changes in the Energy System—National Perspectives. In: Glynn J, Fortes P, Krook-Riekkola A, Labriet M, Vielle M, Kypreos S, Lehtilä A, Mischke P, Dai H, Gargiulo M Informing Energy and Climate Policies Using Energy Systems Models. Springer International Publishing; 2015. pp. 359-387.
Silane derivatives with wide energy gap (approximate to 3.5 eV) containing different electron-withdrawing groups of quinoline and naphthyridine are synthesized and used as the electron transporting materials. The different electron transporting and hole/exciton blocking properties of the silane derivatives are investigated via multilayered structure of organic electrophosphorescent devices by using fac-tris(2-phenylpyridine) iridium (Ir(ppy)(3)) as the phosphorescent emitter. 15.4% of maximum external quantum efficiency (EQE) corresponding to 56.2 cd A(-1) of maximum current efficiency is obtained with a maximum power efficiency of 58.9 lm W-1 by employing di-(4-(1,8-naphthyridin-2-yl) phenyl) diphenylsilane (DNPS) as the electron transporting material, combining with 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline as the hole blocking layer, which is higher than the performance of conventional Alq(3) device. When changing naphthyridine of DNPS to the electron-withdrawing group of quinoline (di-(4-(isoquinolin-4-yl)phenyl) diphenylsilane), only 11.4% of maximum EQE with 41.4 cd A(-1) of maximum current efficiency and 32.5 lm W-1 of a maximum power efficiency is obtained. These indicate that the electron transporting ability increases while the electron-withdrawing group changes from quinoline to naphthyridine, which is also consistent with the calculated reorganization energy.
A new technique whereby cellulase immobilized on aminated silica was applied to catalyze the degradation of dicofol, an organochlorine pesticide. In order to evaluate the performance of free and immobilized cellulase, experiments were carried out to measure the degradation efficiency. The Michaelis constant, Km, of the reaction catalyzed by immobilized cellulase was 9.16 mg/L, and the maximum reaction rate, Vmax, was 0.40 mg/L/min, while that of free cellulase was Km = 8.18 mg/L, and Vmax = 0.79 mg/L/min, respectively. The kinetic constants of catalytic degradation were calculated to estimate substrate affinity. Considering that metal ions may affect enzyme activity, the effects of different metal ions on the catalytic degradation efficiency were explored. The results showed that the substrate affinity decreased after immobilization. Monovalent metal ions had no effect on the reaction, while divalent metal ions had either positive or inhibitory effects, including activation by Mn2 +, reversible competition with Cd2 +, and irreversible inhibition by Pb2 +. Ca2 + promoted the catalytic degradation of dicofol at low concentrations, but inhibited it at high concentrations. Compared with free cellulase, immobilized cellulase was affected less by metal ions. This work provided a basis for further studies on the co-occurrence of endocrine-disrupting chemicals and heavy metal ions in the environment.
Understanding the interactions between natural organic matter (NOM) and zero-valent iron nanoparticles (nano-Fe0) and magnetite nanoparticles (nano-Fe3O4) is essential for evaluating their performance in pollutant remediation, as well as determining their fate and transport in the environment. Batch experiments were performed to investigate the sorption/desorption behaviors of humic acid (HA) on commercially available nano-Fe0 and nano-Fe3O4. The sorption/desorption of HA on nano-Fe0 and nano-Fe3O4 were well described by both the Langmuir model and the modified Langmuir model. The adsorption capacities of HA were 8.77 ± 0.31 mg C/g and 10.05 ± 0.95 mg C/g for nano-Fe0 and nano-Fe3O4, respectively. The interactions of HA with nano-Fe0 and nano-Fe3O4 were highly pH-dependent. On one hand, nano-Fe0 had its maximum adsorption of 11.0 mg C/g HA at pH = 3, which decreased to 0.6 mg C/g when pH increased to 11.9; on the other hand, alkaline condition enhanced HA desorption greatly. At pH = 10.1, after 24 h desorption experiments, nearly 80% of initially adsorbed HA desorbed from the nanoparticles. The interactions of HA with nano-Fe0 and nano-Fe3O4 were also influenced by different ion compositions in solution. Divalent cations (e.g. Ca2+, Mg2+) enhanced HA adsorption significantly, while phosphate nearly eliminated HA adsorption and promoted significantly HA desorption.
Directional light scattering is important in basic research and real applications. This area has been successfully downscaled to wavelength and subwavelength scales With the development of optical antennas, especially single-element nano-antennas. Here, by adding an auxiliary resonant structure to a single-element plasmonic nanoantenna, we show that the highly efficient lowest-order antenna mode can be effectively transferred into inactive higher-order modes. On the basis of this mode conversion, scattered optical fields can be well manipulated by utilizing the interference between different antenna modes. Both broadband directional excitation of surface plasmon polaritons (SPPs) and inversion of SPP launching direction at different wavelengths are experimentally demonstrated as typical examples. The proposed strategy based on mode conversion and mode interference provides new opportunities for the design of nanoscale optical devices, especially directional nanoantennas.
A large data set including surface, aircraft, and laboratory observations of the atomic oxygen-to-carbon (O:C) and hydrogen-to-carbon (H:C) ratios of organic aerosol (OA) is synthesized and corrected using a recently reported method. The whole data set indicates a wide range of OA oxidation and a trajectory in the Van Krevelen diagram, characterized by a slope of -0.6, with variation across campaigns. We show that laboratory OA including both source and aged types explains some of the key differences in OA observed across different environments. However, the laboratory data typically fall below the mean line defined by ambient observations, and little laboratory data extend to the highest O:C ratios commonly observed in remote conditions. OA having both high O:C and high H:C are required to bridge the gaps. Aqueous-phase oxidation may produce such OA, but experiments under realistic ambient conditions are needed to constrain the relative importance of this pathway.
Elemental compositions of organic aerosol (OA) particles provide useful constraints on OA sources, chemical evolution, and effects. The Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) is widely used to measure OA elemental composition. This study evaluates AMS measurements of atomic oxygen-to-carbon (O : C), hydrogen-to-carbon (H : C), and organic mass-to-organic carbon (OM : OC) ratios, and of carbon oxidation state ((OS) over bar (C))for a vastly expanded laboratory data set of multifunctional oxidized OA standards. For the expanded standard data set, the method introduced by Aiken et al. (2008), which uses experimentally measured ion intensities at all ions to determine elemental ratios (referred to here as "Aiken-Explicit"), reproduces known O: C and H: C ratio values within 20% (average absolute value of relative errors) and 12%, respectively. The more commonly used method, which uses empirically estimated H2O+ and CO+ ion intensities to avoid gas phase air interferences at these ions (referred to here as "Aiken-Ambient"), reproduces O: C and H: C of multifunctional oxidized species within 28 and 14% of known values. The values from the latter method are systematically biased low, however, with larger biases observed for alcohols and simple diacids. A detailed examination of the H2O+, CO+, and CO2+ fragments in the high-resolution mass spectra of the standard compounds indicates that the Aiken-Ambient method underestimates the CO C and especially H2O+ produced from many oxidized species. Combined AMS-vacuum ultraviolet (VUV) ionization measurements indicate that these ions are produced by dehydration and decarboxylation on the AMS vaporizer (usually operated at 600 degrees C). Thermal decomposition is observed to be efficient at vaporizer temperatures down to 200 degrees C. These results are used together to develop an "Improved-Ambient" elemental analysis method for AMS spectra measured in air. The Improved-Ambient method uses specific ion fragments as markers to correct for molecular functionality-dependent systematic biases and reproduces known O : C (H : C) ratios of individual oxidized standards within 28% (13 %) of the known molecular values. The error in Improved-Ambient O : C (H : C) values is smaller for theoretical standard mixtures of the oxidized organic standards, which are more representative of the complex mix of species present in ambient OA. For ambient OA, the Improved-Ambient method produces O : C (H : C) values that are 27% (11 %) larger than previously published Aiken-Ambient values; a corresponding increase of 9% is observed for OM : OC values. These results imply that ambient OA has a higher relative oxygen content than previously estimated. The (OS) over bar (C) values calculated for ambient OA by the two methods agree well, however (average relative difference of 0.06 (OS) over bar (C) units). This indicates that (OS) over bar (C) is a more robust metric of oxidation than O : C, likely since (OS) over bar (C) is not affected by hydration or dehydration, either in the atmosphere or during analysis.