Occupational Health and Safety(OHS) in Small and Medium Size Enterprises (SMEs): A Primary Review1 SANTE ET SECURITE

Problems of occupational health and safety(OHS) in small and medium size enterprises(SMEs) in that mainly are private enterprises, are severe in China where as, the corresponding theoretical study are lagged behind regretfully. This paper summarizes the representative progress in this discipline simply. The exploratory results will be used to make an initial evaluation of SMEs needs, and will help orient future research. Key words: Occupational health and safety, Small and Medium Size Enterprises, review Résumé: Les problèmes de Santé et sécurité professionnelles(OHS) dans les petites et moyennes entreprises(PME) sont principalement ceux dans les entreprises privées et sont graves partout en Chine. La recherche théorique correspondante est largement et malheureusement arriérée. Cette thèse fait un résumé sur le progrès représentatif dans cette seule discipline. Les résultats exploratoires seront utilisés pour faire une évaluation initiale des demandes des PMEs et nous aideront l’orientation des recherches futures. Mots-clés: Santé et sécurité professionnelles, les petites et moyennes entreprises, revu

Benzimidazolium 2-(2,4-dichloro­phen­oxy)acetate monohydrate

In the crystal of the title hydrated mol­ecular salt, C7H7N2 +·C8H5Cl2O3·H2O, the components inter­act by way of N—H⋯O and O—H⋯O hydrogen bonds, leading to chains propagating in [100]

N-(1H-1,2,3-Benzotriazol-1-ylmeth­yl)phthalimide

The title compound [systematic name: 2-(1H-1,2,3-benzotriazol-1-ylmeth­yl)isoindole-1,3-dione], C15H10N4O2, was prepared by the reaction of 1H-benzotriazole and 2-bromo­methyl­isoindole-1,3-dione. The benzotriazole and isoindole units are almost planar and make a dihedral angle of 70.2 (1)° (mean planes include C and N atoms). A weak C—H⋯O intra­molecular hydrogen bond involving a carbonyl O atom as acceptor stabilizes the observed mol­ecular conformation

Ultrafast fluorescent decay induced by metal-mediated dipole-dipole interaction in two-dimensional molecular aggregates

Two-dimensional molecular aggregate (2DMA), a thin sheet of strongly interacting dipole molecules self-assembled at close distance on an ordered lattice, is a fascinating fluorescent material. It is distinctively different from the single or colloidal dye molecules or quantum dots in most previous research. In this paper, we verify for the first time that when a 2DMA is placed at a nanometric distance from a metallic substrate, the strong and coherent interaction between the dipoles inside the 2DMA dominates its fluorescent decay at picosecond timescale. Our streak-camera lifetime measurement and interacting lattice-dipole calculation reveal that the metal-mediated dipole-dipole interaction shortens the fluorescent lifetime to about one half and increases the energy dissipation rate by ten times than expected from the noninteracting single-dipole picture. Our finding can enrich our understanding of nanoscale energy transfer in molecular excitonic systems and may designate a new direction for developing fast and efficient optoelectronic devices.Comment: 9 pages, 6 figure

3-(4-Methoxy­phen­yl)-1-(2-nitrophen­yl)prop-2-en-1-one

The title compound, C16H13NO4, was prepared from 2-nitrylhypnone [systematic name: 1-(2-nitrophenyl)ethanone] and 4-methoxy­benzophenone by a Claisen–Schmidt condensation. The dihedral angle formed by the two benzene rings is 80.73 (2). The crystal packing is stabilized by inter­molecular C—H⋯O hydrogen bonds

First detection of GeV emission from an ultraluminous infrared galaxy: Arp 220 as seen with the Fermi Large Area Telescope

Cosmic rays (CRs) in starburst galaxies produce high energy gamma-rays by colliding with the dense interstellar medium (ISM). Arp 220 is the nearest ultra luminous infrared galaxy (ULIRG) that has star-formation at extreme levels, so it has long been predicted to emit high-energy gamma-rays. However, no evidence of gamma-ray emission was found despite intense efforts of search. Here we report the discovery of high-energy gamma-ray emission above 200 MeV from Arp 220 at a confidence level of $\sim 6.3 \sigma$ using 7.5 years of \textsl {Fermi} Large Area Telescope observations. The gamma-ray emission shows no significant variability over the observation period and it is consistent with the quasi-linear scaling relation between the gamma-ray luminosity and total infrared luminosity for star-forming galaxies, suggesting that these gamma-rays arise from CR interactions. As the high density medium of Arp 220 makes it an ideal CR calorimeter, the gamma-ray luminosity can be used to measure the efficiency of powering CRs by supernova (SN) remnants given a known supernova rate in Arp 220. We find that this efficiency is about $4.2\pm2.6\%$ for CRs above 1 GeV.Comment: Accepted by ApJL, 6 pages, 3 figure