An ionization-diffusion mechanism is proposed to understand the first ionization potential (FIP) fractionation as observed in the solar corona and the solar wind. The enrichment of the low-FIP elements (<10 eV) compared to the highFIP elements in a large variety of phenomena, as e.g. slow and fast wind or polar plumes, is explained. Also the special behaviour of the heavy noble gases becomes pe...

The UV spectrum of the bright quasar PHL 1811 at zem = 0.192 reveals a foreground gas system at z = 0.080923 with logN(H I) = 17.98 ± 0.05. We have determined the abundances of various atomic species in this system from a spectrum covering the wavelength range 1160 to 1730 Å recorded at 7 km s resolution by the E140M grating of STIS on the Hubble Space Telescope (HST), supplemented by coverage ...

We report the hydrogen isotope ratio H/H (expressed as dH values) of 8 selected hopanes, tricyclic and tetracyclic terpanes from oils and source rocks in the Potiguar Basin, and of associated formation water. Hopanes ranged in dH value from !79‰ to !142‰, whereas triand tetracyclic terpanes (TTTs) ranged from !137‰ to !225‰. Formation water dH values ranged from !23‰ to !32‰. The most significa...

The formation of formaldehyde via hydrogen atom transfer from the methoxy radical to molecular oxygen is a key step in the atmospheric photochemical oxidation of methane, and in the propagation of deuterium from methane to molecular hydrogen. We report the results of the first investigation of the branching ratio for HCHO and HCDO formation in the CH2DO + O2 reaction. Labeled methoxy radicals (...

BACKGROUND When ascending to the high altitude, people living in low altitude areas will suffer from acute mountain sickness. The aim of this study is to test the hypothesis that whether an oxygen concentration membrane can be made and used to construct a new portable oxygen enrichment device for individuals in acute exposure to the high altitude. METHODS The membrane was fabricated using vin...

The chemical universe database GDB-13, which enumerates 977 million organic molecules up to 13 atoms of C, N, O, S and Cl following simple chemical stability and synthetic feasibility rules, represents a vast reservoir for new fragments. GDB-13 was classified using the MQN-system discussed in the preceding paper for the analysis of PubChem fragments. Two hundred and fifty-five subsets of GDB-13...

1,2-Dichloropropane (1,2-D), a widespread groundwater contaminant, can be reductively dechlorinated to propene by anaerobic bacteria. To shed light on the populations involved in the detoxification process, a comprehensive 16S rRNA gene-based bacterial community analysis of two enrichment cultures derived from geographically distinct locations was performed. Analysis of terminal restriction fra...

In this paper we make comparisons between the observed stable isotopic composition of leaf water and the predictions of the Craig-Gordon model of isotopic enrichment when plants (Cornus stolonifera L.) were exposed to natural, diurnal changes in temperature and humidity in a glasshouse. In addition, we determined the effects of mild water stress on the isotopic composition of leaf water. The mo...