To validate the utility of on-line measurements of UV absorption for the direct quantitation of individual phospholipid molecular species isolated by reverse-phase HPLC, we synthesized 37 different individual molecular species of diacyl choline glycerophospholipids. UV absorbance response factors (integrate UV absorbance/nmole phospholipid) were calculated for all diacyl, alkenylacyl, and alkyl...

In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions,...

Context. Luminous quasars are known to display a sharp steepening of the continuum near 1100 Å. This spectral feature is not well fitted by current accretion disk models, unless comptonization of the disk emission is invoked. Absorption by carbon crystalline dust has been proposed to account for this feature. Aims. Ton 34 (zq = 1.928) exhibits the steepest far-UV decline (Fν ∝ ν ) among the 183...

To resolve the biggest problem in visible-to-UV photon upconversion based on sensitized triplet-triplet annihilation-the quenching of upconverted fluorescence by sensitizers-we discovered a superior sensitizer with less UV absorption intensity that enables highly efficient, low-power (0.78 mW cm(-2)) visible-to-UV upconversion.

for the purpose of increasing the permeability to oxygen and equilibrium water content in contact lenses, polar copolymers with nonionic monomers such as 2-hydroxyethle methacrylate(hema) is used. by adding the polar monomers to (hema), the permeability to oxygen and equilibrium with water content is increased and also the absorption of proteins on lens surface is changed. in this research, the...

Detailed examination of the absorption spectra from dark ocean samples allowed us to identify and deconvolve two distinct chromophores centered at 302 nm (UV) and 415 nm (visible) from the exponential decay curve characteristic of humic substances. The UV chromophore was ubiquitous in intermediate and deep waters, and it has been proposed as the secondary absorption peak of nitrate. The visible...

UV absorption spectroscopy revealed the presence of MDA with characteristic maximum at about 266 nm in the dialysate of the UV irradiated liposomal suspension. The amount of MDA released increased linearly with increasing UV dose. The fluorescence method for the assay of MDA was found nearly 1500-fold more sensitive than the TBA colour reaction method.

We present echelle observations of the intrinsic UV absorption lines in the Seyfert galaxy NGC 4151, which were obtained with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) on 1999 July 19. The UV continuum flux at 1450Å decreased by factor of about four over the previous two years and there was a corresponding dramatic increase in the column densities of th...

Fluorescence emission after two-photon absorption of coumarins and xanthenes in an alcoholic solution was measured in the tuning range of a femtosecond-pulsed titanium-sapphire laser (750-840 nm). Xanthenes, which have a low one-photon absorption in the near UV, show a higher fluorescence signal after two-photon absorption than the UV-excitable coumarins. When fluxes of 10(28) photons/(cm(2) s)...