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151.
Jacques Brunet Daniel Paquer Philippe Rioult 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):377-379
Abstract Treatment of aliphatic γ-oxo esters with hydrogen chloride/hydrogen sulfide gives three sulfur compounds: an alkyl-5-mercaptothiolan-2-one, an alkyl-4-thiolen-2-one and an alkyl-3-thiolen-2-one. Chemical properties of these products are reported. With aromatic γ-oxo esters we obtain a thiophenic compound. 相似文献
152.
Rizzi J Weitkamp T Guérineau N Idir M Mercère P Druart G Vincent G da Silva P Primot J 《Optics letters》2011,36(8):1398-1400
We present in this Letter a type of quadriwave lateral shearing interferometer for x-ray phase imaging. This device is based on a phase chessboard, and we take advantage of the large spectrum of the source to produce interferograms with a propagation-invariant contrast. Such a grating has been created for hard x-ray interferometry and experimentally tested on a synchrotron beamline at Soleil. 相似文献
153.
Casitas A Canta M Solà M Costas M Ribas X 《Journal of the American Chemical Society》2011,133(48):19386-19392
Copper-catalyzed halide exchange reactions under very mild reaction conditions are described for the first time using a family of model aryl halide substrates. All combinations of halide exchange (I, Br, Cl, F) are observed using catalytic amounts of Cu(I). Strikingly, quantitative fluorination of aryl-X substrates is also achieved catalytically at room temperature, using common F(-) sources, via the intermediacy of aryl-Cu(III)-X species. Experimental and computational data support a redox Cu(I)/Cu(III) catalytic cycle involving aryl-X oxidative addition at the Cu(I) center, followed by halide exchange and reductive elimination steps. Additionally, defluorination of the aryl-F model system can be also achieved with Cu(I) at room temperature operating under a Cu(I)/Cu(III) redox pair. 相似文献
154.
Dimerization of Pyramidalized 3,4,8,9‐Tetramethyltetracyclo [4.4.0.03,9.04,8]dec‐1(6)‐ene to a Hydrocarbon Featuring Four Cyclohexane Rings in Boat Conformations
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Matias Rey‐Carrizo Marta Barniol‐Xicota Dr. Mercè Font‐Bardia Prof. Dr. Santiago Vázquez 《Angewandte Chemie (International ed. in English)》2014,53(31):8195-8199
The synthesis, chemical trapping, and dimerization of a highly pyramidalized alkene is reported. Its dimer is a unique nonacycle featuring three planar cyclobutane rings, four cyclopentane rings, and four cyclohexane rings in boat conformations. The X‐ray diffraction analysis showed a H–H distance between the flagpole hydrogen atoms of 1.999 Å and a separation of 2.619 Å between the two flagpole carbon atoms. The three cyclobutane rings of the dimer were thermally stable. 相似文献
155.
The different impurity levels in crystals are investigated basing on a deformation potential model which is related to the impurity size effect. The donor levels such as Ed(O) and Ed(Se) in lightly doped GaP are found to be equal to 898.55 and 103.00 meV, respectively, in perfect agreement with the experimental results of Vink et al. 相似文献
156.
We consider aggregation of products with similar characteristics in a two-level hierarchical production planning model. A robust aggregate plan at the upper level is such that, at the lower level, a disaggregation policy exists even when detailed demands may vary within some given bounds. We provide necessary and sufficient conditions for the robustness of an aggregate plan and obtain a closed form expression of these conditions. A set of more manageable sufficient conditions is also presented.Institut National des Sciences Appliquées de Toulouse. 相似文献
157.
T Dine C Brunet M Luyckx M Cazin P Gosselin J L Cazin 《Biomedical chromatography : BMC》1990,4(1):20-23
A rapid sensitive and selective isocratic technique was developed for the analysis of plasma epirubicin and three of its known fluorescent metabolites epirubicinol, 4'-O-beta-D-glucuronyl-4'-epidoxorubicin and 4'-O-beta-D-glucuronyl 1,3-dihydro-4'-epidoxorubicin, with daunorubicin as an internal standard, by using high performance liquid chromatography (HPLC) with fluorescence detection and a 'Hypersil ODS' column. The drugs were easily and efficiently extracted with a Sep-Pak C18 cartridge and the mean recoveries were greater than 85%. Intraassay and Interassay coefficients of variation (plasma samples) were better than 8.25%. An example of pharmacokinetic study obtained in a cancer patient after intravenous injection of epirubicine is described. 相似文献
158.
159.
It is shown that a basis for a symmetric representation of U(n) ?U(n) can be constructed from the matrix of a representation of U(n). This result is studied in detail for the Wey bases of U(n). 相似文献
160.
Brunet P Lapierre F Thomy V Coffinier Y Boukherroub R 《Langmuir : the ACS journal of surfaces and colloids》2008,24(19):11203-11208
The paper reports on the comparison of the wetting properties of superhydrophobic silicon nanowires (NWs), using drop impact impalement and electrowetting (EW) experiments. A correlation between the resistance to impalement on both EW and drop impact is shown. From the results, it is evident that when increasing the length and density of NWs (i) the thresholds for drop impact and EW irreversibility increase and (ii) the contact-angle hysteresis after impalement decreases. This suggests that the structure of the NW network could allow for partial impalement, hence preserving the reversibility, and that EW acts the same way as an external pressure. The most robust of our surfaces shows a threshold to impalement higher than 35 kPa, while most of the superhydrophobic surfaces tested so far have impalement thresholds smaller than 10 kPa. 相似文献