Research on the Influence of Ocean Atmosphere to Infrared Detection

Ocean atmospheric transmittance is an important factor to influence detecting distance of infrared system. The influence efficiency of infrared detection is studied by using modtran, on the basis of studying the character of infrared transmission. Firstly, major absorption band of vapor, carbon dioxide, ozone and vapor continuum and the change of transmittance in boundary layer, troposphere and stratosphere are analyzed. Secondly, atmospheric window transmittance of navy maritime aerosol in horizontal path and slant path is analyzed, and the influence of four types of maritime aerosol is also analyzed for navy maritime aerosol. Lastly, the influence of five model atmospheres to total transmittance is analyzed.

Twelve years of global observations of formaldehyde in the troposphere using GOME and SCIAMACHY sensors

This work presents global tropospheric formaldehyde columns retrieved from near-UV radiance measurements performed by the GOME instrument onboard ERS-2 since 1995, and by SCIAMACHY, in operation on ENVISAT since the end of 2002. A special effort has been made to ensure the coherence and quality of the CH2O dataset covering the period 1996–2007. Optimised DOAS settings are proposed in order to reduce the impact of two important sources of error in the derivation of slant columns, namely, the polarisation anomaly affecting the SCIAMACHY spectra around 350 nm, and a major absorption band of the O4 collision complex centred near 360 nm. The air mass factors are determined from scattering weights generated using radiative transfer calculations taking into account the cloud fraction, the cloud height and the ground albedo. Vertical profile shapes of CH2O are provided by the global CTM IMAGES based on an up-to-date representation of emissions, atmospheric transport and photochemistry. A comprehensive error analysis is presented. This includes errors on the slant columns retrieval and errors on the air mass factors which are mainly due to uncertainties in the a priori profile and in the cloud properties. The major features of the retrieved formaldehyde column distribution are discussed and compared with previous CH2O datasets over the major emission regions.

Synthesis of Galloyl-Coenzyme A Thioester

Galloyl-CoA, a potential intermediate in the biosynthesis of gallotannins, has been prepared via N-succinimidyl 4-O-β-ᴅ-glucosidogallate and 4-O-β-ᴅ-glucosidogalloyl-CoA. Besides a major absorption band at 261 nm, the UV-spectra of the purified thioester and its corresponding 4-O-glucoside contain a longer wavelenght absorption band due to the thioester linkage at 305 nm (galloyl-CoA) or at 290 nm (shoulder, glucosidogalloyl-CoA). The molar extinction coefficients ε of the two thioesters were determined via the iron-complex of 4-O-β-ᴅ-glucosidogalloyl hydroxamic acid; ε261-values of 19.5 × 106 [cm2 mol-1] and 21.5 × 106 [cm2 mol-1] were calculated for galloyl-CoA and its glucoside, respectively. Difference spectra, i.e. absorbance before esterolysis and after, revealed maximal absorption of the thioester bond at 310 nm (⊿ε = 7.4 × 106 [cm2 mol-1]) for galloyl-CoA and at 282 nm (⊿ε = 7.2 × 106 [cm2 mol-6]) for glu- cosidogalloyl-CoA. The two thioesters were further characterized by determining their half-lifes during hydroxylaminolysis and alkaline hydrolysis.

The Infrared Spectra of Some 1-(2-Thienyl)-3- and -4-Thiaalkanes

The infrared spectra of six 1-(2-thienyl)-3-thiaalkanes and seven 1-(2-thienyl)-4-thiaalkanes (molecular weights from 186 to 270) were obtained for the 4000 to 400 cm−1 range. These spectra are compared with spectra of other thiophene ring compounds substituted in the 2-position for their characteristic absorption bands. The spectra agree with other spectra as to the major absorption band around 680 cm−1 and the 2-substitution overtone pattern. A method of distinguishing between the two groups of compounds from moderate peaks in the 600 to 500 cm−1 (KBr) region is shown. Interference from the 2-alkylthiophenes and the 1-(2-thienyl)-1-thiaalkanes does not occur.