Search results for "Zen"
showing 10 items of 3479 documents
Targeted NGS for species level phylogenomics: “made to measure” or “one size fits all”?
2017
Targeted high-throughput sequencing using hybrid-enrichment offers a promising source of data for inferring multiple, meaningfully resolved, independent gene trees suitable to address challenging phylogenetic problems in species complexes and rapid radiations. The targets in question can either be adopted directly from more or less universal tools, or custom made for particular clades at considerably greater effort. We applied custom made scripts to select sets of homologous sequence markers from transcriptome and WGS data for use in the flowering plant genus Erica (Ericaceae). We compared the resulting targets to those that would be selected both using different available tools (Hyb-Seq; M…
Influence of preparation conditions on the catalytic performance of mo/h-zsm-5 for methane dehydroaromatization
2021
[EN] Methane, the main component of natural gas, is an interesting source of chemicals and clean liquid fuels, and a promising alternative raw material to oil. Among the possible direct routes for methane conversion, its aromatization under non-oxidative conditions has received increasing attention, despite the low conversions obtained due to thermodynamic limitations, because of its high selectivity to benzene. Mo/H-ZSM-5, the first bifunctional zeolite-catalyst proposed for this reaction, is still considered as one of the most adequate and has been widely studied. Although the mono- or bifunctional nature of the MDA mechanism is still under debate, it is generally accepted that the Mo spe…
Photomodulation of Two-Dimensional Self-Assembly of Azobenzene-Hexa-peri-hexabenzocoronene-Azobenzene Triads
2019
International audience; Achieving exquisite control over self-assembly of functional polycyclic aromatic hydrocarbons (PAH) and nanographene (NG) is essential for their exploitation as active elements in (nano)technological applications. In the framework of our effort to leverage their functional complexity, we designed and synthesized two hexa-peri-hexabenzocoronene (HBC) triads, pAHA and oAHA, decorated with two light-responsive azobenzene moieties at the pseudo-para and ortho positions, respectively. Their photoisomerization in solution is demonstrated by UV–vis absorption. 1H NMR measurements of oAHA suggested 23% of Z-form can be obtained at a photostationary state with UV irradiation …
Thermo- and Light-Responsive Polymers Containing Photoswitchable Azobenzene End Groups
2009
Telechelic thermo- and light-responsive polymers based on poly(oligo(ethylene glycol) methyl ether methacrylate) P(OEGMA) with azobenzene functionalities at the end groups were synthesized. In a reversible addition−fragmentation chain transfer (RAFT) polymerization using a functionalized chain transfer agent (CTA) containing a pentafluorophenyl (PFP) activated ester, oligo(ethylene glycol) methyl ether methacrylate (OEGMA, Mn ∼ 300 g mol−1) could successfully be polymerized with good control over molecular weight, very high conversions, and narrow molecular weight distributions. Polymers derived from this CTA possessed an activated ester at the α-end of the polymer chain as well as a dithio…
Della natura, dell'arte o della metamorfosi
2008
Il saggio analizza il concetto di natura nell'opera teorica e artistica di S.M. Ejzenstejn
Aerosol optical properties and direct radiative forcing based on measurements from the China Aerosol Remote Sensing Network (CARSNET) in eastern China
2018
Aerosol pollution in eastern China is an unfortunate consequence of the region's rapid economic and industrial growth. Here, sun photometer measurements from seven sites in the Yangtze River Delta (YRD) from 2011 to 2015 were used to characterize the climatology of aerosol microphysical and optical properties, calculate direct aerosol radiative forcing (DARF) and classify the aerosols based on size and absorption. Bimodal size distributions were found throughout the year, but larger volumes and effective radii of fine-mode particles occurred in June and September due to hygroscopic growth and/or cloud processing. Increases in the fine-mode particles in June and September caused AOD440 nm &…
Retrieval of characteristic parameters for water vapour transmittance in the development of ground based Sun-Sky radiometric measurements of columnar…
2014
Abstract. Sun–sky radiometers are instruments created for aerosol study, but they can measure in the water vapour absorption band allowing the estimation of columnar water vapour in clear sky simultaneously with aerosol characteristics, with high temporal resolution. A new methodology is presented for estimating calibration parameters (i.e. characteristic parameters of the atmospheric transmittance and solar calibration constant) directly from the sun–sky radiometer measurements. The methodology is based on the hypothesis that characteristic parameters of the atmospheric transmittance are dependent on vertical profiles of pressure, temperature and moisture occurring at each site of measurem…
Precipitable water vapour content from ESR/SKYNET sun-sky radiometers: validation against GNSS/GPS and AERONET over three different sites in Europe
2018
The estimation of the precipitable water vapour content (W) with high temporal and spatial resolution is of great interest to both meteorological and climatological studies. Several methodologies based on remote sensing techniques have been recently developed in order to obtain accurate and frequent measurements of this atmospheric parameter. Among them, the relative low cost and easy deployment of sun–sky radiometers, or sun photometers, operating in several international networks, allowed the development of automatic estimations of W from these instruments with high temporal resolution. However, the great problem of this methodology is the estimation of the sun-photometric calibration par…
5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrapentoxycalix[4]arene
2005
The molecule of the title compound, C64H96O4, adopts the typical pinched-cone conformation. The dihedral angles between the reference plane (defined by the C atoms of the methylene bridges) and the benzene rings are 86.88 (4), 136.64 (5), 87.22 (4) and 133.99 (4)°.
Green determination of the presence of volatile organic compounds in vehicle repair shops through passive sampling.
2012
A simple, fast and green direct analytical methodology has been developed to evaluate the concentration level of volatile organic compounds (VOCs) in indoor areas of vehicle repair shops using membrane devices as passive samplers. VOCs retained in the samplers were directly determined without any sample pre-treatment and avoiding the use of solvents by head space (HS) coupled to gas chromatography-mass spectrometry (GC-MS) in only 20 min. Benzene, toluene, tetrachloroethene, m,p-xylene and o-xylene were found at concentration levels from 0.1 to 11.2 mg m(-3).