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51.
L. Audirac P. Ascher B. Blank C. Borcea B. A. Brown G. Canchel C. E. Demonchy F. de Oliveira Santos C. Dossat J. Giovinazzo S. Grévy L. Hay J. Huikari S. Leblanc I. Matea J. -L. Pedroza L. Perrot J. Pibernat L. Serani C. Stodel J. -C. Thomas 《The European Physical Journal A - Hadrons and Nuclei》2012,48(12):1-12
The two-proton radioactivity of 45Fe was studied experimentally with a time projection chamber. The aim of the experiment was the reconstruction of the proton tracks in three dimensions. Energy and angular correlations have been determined and the data are compared with theoretical models, in particular with a three-body model. Moreover, the decay of 43Cr was studied and ??-delayed one-, two- and three-proton emission could be established. The correlations observed for ??-delayed two-proton emission favour a sequential emission. Finally, ??-delayed two-proton emission was observed for the first time for 51Ni. 相似文献
52.
The crystallization of NH4NO3 under compressed Langmuir monolayers of carboxybe-taine(C22N3COO-),C22H15N(CH2)3(CH2)3COO--[C22N3COO-] and dioleoyl-L-a-lecithin(DOPC) was studied by means of π-A. ΔV-A and fluorescence microscopy (FM). The surface pressure, surface potential and molecular area of C22N3COO- were decreased on the NH4NO3 solution subphase. The surface pressure and molecular area of DOPC was increased. The surface potential of DOPC was decreased. We can directly observe the surface crystallization of NH4NO3 by FM. The results revaled that C22N3COO- monolayer was the promoter of NH4NO3 surface crystallization. In contrast,DOPC monolayer was the inhibitor of the surface crystallization of NH4NO3. 相似文献
53.
Flore DagornLok-Hang Yan Edmond GravelKarine Leblanc Alexandre MaciukErwan Poupon 《Tetrahedron letters》2011,52(27):3523-3526
Several aspects of the unusual behavior of C6C2 aldehydes and amines during the formation of pyridiniums in analogy with the historical Chichibabin pyridine synthesis are clarified in this Letter. Interesting biosynthetic consequences are also discussed within two classes of polycyclic alkaloids of marine origin. 相似文献
54.
Dr. Edmond Gravel Abha Harfouche Dr. Rim Salame Karine Leblanc Dr. Alexandre Maciuk Prof. Dr. Erwan Poupon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(43):14515-14520
Mixtures of tryptamine and reactive C5 units, presumably derived from lysine in nature, were studied to ascertain the spontaneous formation of the complex polycyclic alkaloid nitrarine. Several indolic compounds tracing the unified metabolism within the Nitraria genus were also characterized. 相似文献
55.
56.
The brain is believed to be particularly vulnerable to arsenic due to its high oxygen consumption rate and high level of polyunsaturated fatty acids and relatively high rate of oxygen free radical generate without commensurable level of arsenic. Hence, in the present work an attempt is made to study the changes in the biochemical contents in the brain tissues of edible fish Labeo rohita due to arsenic intoxication using Fourier Transform Infrared (FT-IR) spectroscopy. FT-IR spectra reveal significant differences in absorbance intensities between the control and arsenic intoxicated brain tissues, reflecting an alteration on the major biochemical constituents, such as lipids, proteins and nucleic acids of the brain tissues of L. rohita due to arsenic intoxication. Further, the administration of antidote DMSA improves the protein and lipid contents significantly in the brain tissues when compared to arsenic intoxicated tissues. The decrease in α-helix structure due to arsenic intoxication might be responsible for the increase in β-sheet secondary structures, which is consistent with the mechanism of β-sheet formation. 相似文献
57.
Three new monodimensional hybrid metal (Ti, In, Al) fluorides are synthesized with ethylenediamine (en) as a templating agent in solvothermal conditions assisted by microwave heating. All structures involve inorganic chains built up from TiO2F4 octahedra connected by two opposite O2− vertices in [H2en]·(TiOF4) (I), from InF6(H2O) pentagonal bipyramids linked by F–F edges in [H2en]·(InF4(H2O))2·H2O (II) and from (Al7F30)9− polyanions sharing two opposite AlF6 octahedra in [H2en]3·(Al6F24) (III). I is tetragonal, P4/ncc, a = 12.761(3) Å, c = 8.041(3) Å; II is orthorhombic, F2dd, a = 6.904(5) Å, b = 16.559(5) Å, c = 19.777(4) Å and III is monoclinic, P21/n, a = 9.387(2) Å, b = 6.710(2) Å, c = 21.513(6) Å, β = 97.18(3)°. 相似文献
58.
J. Touret X. Bourdon M. Leblanc R. Retoux J. Renaudin V. Maisonneuve 《Journal of fluorine chemistry》2001,110(2):133-138
The synthesis and structural characterization of new hydroxo-fluorometallates [H3N(CH2)6NH3]2M(F,OH)7·H2O (M=Al, In) are presented. Their preparation is achieved in solvothermal conditions by microwave or classical heating. The isotopic structures, determined by single crystal X-ray diffraction, are triclinic with the space group P–1. The structural arrangement can be described from isolated MX6 (X=F, OH) octahedra connected by diprotonated diaminohexane via a complex network of hydrogen bonds. X− anions and water molecules are found between the organic chains. A study by 19F NMR of the Al compound confirms a statistical occupancy of fluorine sites by hydroxyl groups and the occurrence of isolated F− anions. 相似文献
59.
Alexandre Leblanc 《Annals of the Institute of Statistical Mathematics》2012,64(5):919-943
It is a known fact that some estimators of smooth distribution functions can outperform the empirical distribution function in terms of asymptotic (integrated) mean-squared error. In this paper, we show that this is also true of Bernstein polynomial estimators of distribution functions associated with densities that are supported on a closed interval. Specifically, we introduce a higher order expansion for the asymptotic (integrated) mean-squared error of Bernstein estimators of distribution functions and examine the relative deficiency of the empirical distribution function with respect to these estimators. Finally, we also establish the (pointwise) asymptotic normality of these estimators and show that they have highly advantageous boundary properties, including the absence of boundary bias. 相似文献
60.
Andrew Taylor Robert L. Jones Alain Leblanc Olav Mazarrasa Mi-Young Lee Patrick J. Parsons Marina Patriarca Jean-Philippe Weber Cas Weykamp 《Accreditation and quality assurance》2009,14(8-9):461-466
An under-recovery of inorganic mercury added to urine and a wide range of results is observed in quality assessment schemes (EQAS) for trace elements. Furthermore, the under-recoveries are inconsistent suggesting features associated with the urine matrix may make the mercury unavailable for measurement. To investigate the instability of mercury in urine the following experiments were set up: (1) a sample of Hg2+ in water with various ‘stabilizers’ added was sent to UK external quality assessment scheme participants. (2) Urine was collected from volunteers who also completed a 3-day food diary. Hg, Ca, Mg, Se, uric acid, phosphate, creatinine, reducing substances and protein were measured. Inorganic mercury was spiked into the urine, stabilizers were added and the mercury determined following storage. The results confirmed under-recovery of mercury in association with the urine matrix. Further investigations of how urinary components affect the measurement of mercury are necessary. 相似文献