A Robust,Precious-Metal-Free Dye-Sensitized Photoanode for Water Oxidation: A Nanosecond-Long Excited-State Lifetime through a Prussian Blue Analogue

Herein, we establish a simple synthetic strategy affording a heterogeneous, precious metal-free, dye-sensitized photoelectrode for water oxidation, which incorporates a Prussian blue (PB) structure for the sensitization of TiO₂ and water oxidation catalysis. Our approach involves the use of a Fe(CN)₅ bridging group not only as a cyanide precursor for the formation of a PB-type structure but also as an electron shuttle between an organic chromophore and the catalytic center. The resulting hetero-functional PB-modified TiO₂ electrode demonstrates a low-cost and easy-to-construct photoanode, which exhibits favorable electron transfers with a remarkable excited state lifetime on the order of nanoseconds and an extended light absorption capacity of up to 500 nm. Our approach paves the way for a new family of precious metal-free robust dye-sensitized photoelectrodes for water oxidation, in which a variety of common organic chromophores can be employed in conjunction with CoFe PB structures.     

Moderate deviations for stationary sequences of Hilbert-valued bounded random variables

In this paper, we derive the Moderate Deviation Principle for stationary sequences of bounded random variables with values in a Hilbert space. The conditions obtained are expressed in terms of martingale-type conditions. The main tools are martingale approximations and a new Hoeffding inequality for non-adapted sequences of Hilbert-valued random variables. Applications to Cramér-Von Mises statistics, functions of linear processes and stable Markov chains are given.     

Exact and numerical solutions of generalized Drinfeld-Sokolov equations

In this Letter, we consider a system of generalized Drinfeld-Sokolov (gDS) equations which models one-dimensional nonlinear wave processes in two-component media. We find some exact solutions of gDS by using tanh function method and we also obtain a numerical solution by using the Adomian's Decomposition Method (ADM).     

Synthesis,characterization, catalase functions and DNA cleavage studies of new homo and heteronuclear Schiff base copper(II) complexes

A new tetradentate diimine–dioxime ligand containing a donor set of N₄, and its homo-, heterodinuclear and homotrinuclear copper(II) complexes were prepared and characterized on the basis of their elemental analysis, FT-IR, ¹H and ¹³C NMR spectra, molar conductivity and magnetic moment measurements. The extraction ability of N,N′′-bis[1-biphenyl-2-hydroxyimino-1-ethylidene]-diethylenetriamine was also evaluated in chloroform by using several transition metal picrates such as Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II) and Hg(II). It has been seen that the ligand shows strong binding ability toward the copper(II) ion. Moreover, the catalytic activities of the complexes for the disproportionation of hydrogen peroxide were investigated in the presence of imidazole. The synthesized complexes display efficiency in the disproportion reactions of hydrogen peroxide, producing water and dioxygen in catalase-like activity. The interaction between these complexes and DNA has also been investigated by agarose gel electrophoresis. We found that the homo- and heterodinuclear copper complexes can cleave supercoiled pBR322 DNA to nicked and linear forms. The dinuclear complexes including phenanthroline (2–4), with H₂O₂ as a co-oxidant, exhibited the strongest cleaving activity.     

Time-wavelength assignment algorithms: Hardware/performance tradeoffs

In this paper we present time-wavelength assignment algorithms that consider the following system parameters: (1) the system hardware in terms of the transmitters' and receivers' tuning capabilities (slow or fast tuning) and (2) the traffic matrix. The ulgorithms' objective is to maximize the bandwidth efficiency, i.e., to minimize the frame duration. Each algorithm will be suitable for a different set of system parameters. We present trade-offs between the system hardware and the algorithm' performance for various traffic patterns. These trade-offs can be used as guidelines for the system designer that needs to decide the system hardware for a given traffic pattern and required system performance. Moreouer, for a given system hardware and traffic patterns, each node can distributively decide which algorithm should be used, i.e., the algorithm that will maximize the system performance.     

Background correction by wavelength modulation using a microcomputer in atomic emission spectrometry

An Apple IIe microcomputer was employed to correct the background radiation in electrothermal atomization atomic emission spectrometry (ETA-AES). In ETA-AES, black-body radiation from the atomizer as well as any broadband molecular emission should be corrected to obtain an atomic signal alone. A quartz plate run by a G325D galvanometric motor was placed before the exit slit of a 256 mm Littrow monochromator. Improvements by a novel pulsed 3-step square waveform are demonstrated compared with the ordinatry 3-step square waveform. A soft delay was also applied in order to avoid taking data at transition stages of the quartz plate. A line and a continuum source are used to simulate offsetting of the DC component of the signal prior to the ADC. This provides a better utilization of the full dynamic range of the converter.     

Design and characterization of Bodipy derivatives for bulk heterojunction solar cells

Two electron rich Bodipy dyes with strong absorptivities in the visible region were designed and synthesized as potential electron donors in bulk heterojunction photovoltaic constructs. Overall efficiency is above 1%, with impressive responsiveness at both UV and near-IR ends of the visible spectrum. Computational studies reveal an unexpected effect of meso-substituents on the electron transfer efficiency.