Optical and electrical experiments at some transition-metal oxide foil-electrolyte interfaces2

Metal oxide layers formed from transition-metal foils oxidized by heating in air have been examined for their photoelectrolytic response. The metals examined are Y, Ti, Zr, Hf, V, Nb, Ta, Mo, W, and Pt. Weak photoeffects are observed for oxide layers of all of these metals. Sizable light-dependent oxygen gas evolution rates are found in Ti and also in W oxides. The spectral dependence of the oxygen response in these compounds is investigated, and interpretation is given of these experiments.     

Higher Weierstrass points on

We study the arithmetic properties of higher Weierstrass points on modular curves for primes . In particular, for , we obtain a relationship between the reductions modulo of the collection of -Weierstrass points on and the supersingular locus in characteristic .

     

Generalized Kramers–Kronig relations and sum rules for moments and powers of degenerate four wave mixing susceptibility

Optical Review - Generalized Kramers–Kronig (K–K) type dispersion relations and sum rules are derived in the static limit for the moments of the degenerate four wave mixing...     

1,3,5,7‐Tetraselena‐2,4,6,8(2,5)‐tetrathiophenaoctaphane

The novel title tetraselenacalix[4]arene, C₁₆H₈S₄Se₄ or [(C₄H₂S)Se]₄, has a centrosymmetric cyclic molecular structure with approximate C_2h molecular symmetry. The four thienyl rings are joined together by Se bridges and exhibit a syn–syn–anti–anti arrangement around the mol­ecule. The lattice consists of skewed stacks of mol­ecules, with chalcogen–chalcogen close contacts binding the stacks together, forming a two‐dimensional network of mol­ecules.     

Versatile bio-ink for covalent immobilization of chimeric avidin on sol-gel substrates

A bio-ink for covalent deposition of thermostable, high affinity biotin-binding chimeric avidin onto sol-gel substrates was developed. The bio-ink was prepared from heterobifunctional crosslinker 6-maleimidohexanoic acid N-hydroxysuccinimide which was first reacted either with 3-aminopropyltriethoxysilane or 3-aminopropyldimethylethoxysilane to form silane linkers 6-maleimide-N-(3-(triethoxysilyl)propyl)hexanamide or -(ethoxydimethylsilyl)propyl)-hexanamide. C-terminal cysteine genetically engineered to chimeric avidin was reacted with the maleimide group of silane linker in methanol/PBS solution to form a suspension, which was printed on sol-gel modified PMMA film. Different concentrations of chimeric avidin and ratios between silane linkers were tested to find the best properties for the bio-ink to enable gravure or inkjet printing. Bio-ink prepared from 3-aminopropyltriethoxysilane was found to provide the highest amount of active immobilized chimeric avidin. The developed bio-ink was shown to be valuable for automated fabrication of avidin-functionalized polymer films.     

Measuring tablet porosity using multispectral imaging system

A multispectral imaging system with computer controlled light source of 16 light emitting diodes is applied for measuring of tablet porosity. The system is based on a subspace vector model of surface reflection. The measured spectral data are compressed on the stage of measurement and used directly for the discrimination of tablets with different porosity. The experimental results demonstrate that the multispectral imaging system is a potential method for tablet porosity measurement.     

Terahertz absorption spectra of commonly used antimalarial drugs

Optical Review - Terahertz (THz) spectra from the pure forms [i.e. the active pharmaceutical ingredients (APIs)] of four commonly used antimalarial drugs are reported. The well-defined spectral...     

On the irreducibility of Hecke polynomials

Let be the characteristic polynomial of the th Hecke operator acting on the space of cusp forms of weight for the full modular group. We record a simple criterion which can be used to check the irreducibility of the polynomials . Using this criterion with some machine computation, we show that if there exists such that is irreducible and has the full symmetric group as Galois group, then the same is true of for each prime .

     

Modularity of a Certain Calabi-Yau Threefold

 The Langlands program predicts that certain Calabi-Yau threefolds are modular in the sense that their L-series correspond to the Mellin transforms of weight 4 newforms. Here we prove that the L-function of the threefold given by is , the unique normalized eigenform in .