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71.
Michael Bs Willy P. Burkard Jean-Luc Moreau Peter Schnholzer 《Helvetica chimica acta》1990,73(4):932-939
The synthesis of the title compound 2 and its diastereoisomer 3 was accomplished using tricarbonyl[1-5-n-(4-methoxycyclohexa-2,4-dien-1-yl)]iron tetrafluoroborate ( 4 ) as a precursor to the cyclohexanone ring. The assignments of the relative configurations of 2 and 3 are based on the X-ray analysis of compound 3 . Both compounds 2 and 3 are potent inhibitors of neuronal noradrenaline uptake in rats with similar potencies in vitro as compared to amitriptyline and desipramine. Compounds 2 and 3 are less potent as serotonin-uptake inhibitors, very weak inhibitors of dopamine uptake, and virtually devoid of antinociceptive activity. 相似文献
72.
Yannick Rio Jean-Franois Nicoud Jean-Luc Rehspringer Jean-Franois Nierengarten 《Tetrahedron letters》2000,41(52):10207-10210
Triethylene glycol terminated poly(aryl ether) dendritic branches with an aldehyde function at the focal point have been prepared and attached to C60 by a 1,3-dipolar cycloaddition. 相似文献
73.
Agnès Rivaton Sylvain Chambon Jean-Luc Gardette Stéphane Guillerez 《Polymer Degradation and Stability》2010,95(3):278-2251
Polymer-based organic solar cells are known to offer a poor stability in real use conditions, and the photodegradation of the active organic layer plays an important role in the reduced lifetime of the devices. This paper focuses on the photodegradation of two conjugated polymers used in organic solar cells, namely poly(2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene (MDMO-PPV) and poly(3-hexyylthiophene) (P3HT), and their blends with [60]PCBM (methano-fullerene[6,6]-phenyl C61-butyric acid methyl ester), a fullerene derivative. MDMO-PPV and P3HT thin films were submitted to photoageing (λ > 300 nm) in the presence and in the absence of oxygen. The mechanisms by which these polymers degrade were elucidated. P3HT, pristine and blended with PCBM, was shown to be much more stable under illumination than MDMO-PPV. The results showed that, if deposited on an inert substrate and well protected from oxygen with a convenient encapsulation, P3HT:PCBM based active layer should be intrinsically stable for several years in use conditions. 相似文献
74.
Candice Grivel Jean-Louis Rocca Davy Guillarme Jean-Luc Veuthey Sabine Heinisch 《Journal of chromatography. A》2010,1217(4):459-472
Reversed phase gradient elution is the method of choice for pharmaceuticals analysis since it allows reducing the analysis time while improving both the quality of the separation and the detection limits. The current trends are towards faster separations which can be achieved thanks to equipments withstanding ultra-high pressures and/or high temperatures. Under such conditions, gradient separations can be carried out within a few minutes or even a few tens of seconds. A long equilibration time in addition to the gradient time can be therefore very detrimental. In this work, we investigated the extent to which the gradient equilibration time can be reduced and which parameters mainly affect the retention variability of ionizable compounds when using volatile buffers. We first found out an excellent repeatability between run-to-run experiments whatever the equilibration time and the operating conditions. We then pointed out the key operating parameters which allow achieving reproducible runs when varying the equilibration time between runs. With a view of reducing the equilibration time, the effects of various conditions were examined. The latter include the type of additive for mobile phase pH adjustment, the initial eluent composition, the type of stationary phase, the temperature and the flow-rate. Although much remains to be understood about the equilibration process, our study allows making progress in the knowledge of this phenomenon. Based on the present results, a beneficial effect of both temperature and flow-rate was highlighted and operating conditions leading to faster column equilibration are suggested. 相似文献
75.
Jorge Gutierrez Denis Pache Myriam Ariaudo Jean-Luc Gautier 《Analog Integrated Circuits and Signal Processing》2010,62(3):313-318
This paper presents a high speed, 9-bit RF Digital-to-Analog Converter based on a new architecture implemented in a 0.13 μm
BiCMOS process and able to adjust the output power by 45 dB to meet gain control requirements of the new communications standards
with a SFDR >25 dBc. The maximum test-demonstrated frequency is 1.4 GHz and the chip dissipates <25 mW. 相似文献
76.
Rached Salhi Ramzi Maalej Yannick Guyot Laetitia Rapenne Jean-Luc Deschanvres 《Journal of luminescence》2011,131(11):2311-2316
Erbium-doped Y2O3 films were prepared by aerosol-UV assisted metal-organic chemical vapour deposition (MOCVD) at 410 °C. The effects of humidity of carrier gas and UV-assistance on their structure and optical properties were investigated on the as-deposited and thermal annealed films using infrared spectroscopy, X-ray diffraction and transmission electron microscopy. It was found that the as-deposited Er:Y2O3 films crystallise in the Y2O3 cubic structure and present a very low organic contamination when the deposition takes place under high air humidity and, even better, with UV-assistance. After annealing, two different structural phases are observed corresponding to the cubic and the monoclinic structures of Y2O3. The Er3+ luminescence analysed in the visible and IR regions, shows the classical green transitions. The best optical properties were obtained with as-deposited and annealed Er:Y2O3 films grown under high air humidity with UV-assistance. Under such deposition conditions, 4I13/2 lifetimes was found to be 3.07 and 6.1 ms for films annealed at 800 and 1000 °C, respectively, and up-conversion phenomena were underlined. This indicates that the deposition conditions, in particular air humidity, play an important role in the luminescent properties even after annealing. 相似文献
77.
In inflationary models, the predicted amplitude of primordial density perturbations Q is much larger than the observed value (~10(-5)) for natural choices of parameters. To explain the requisite exponential fine-tuning, anthropic selection is often invoked, especially in cases where microphysics is expected to produce a complex energy landscape. By contrast, we find examples of ekpyrotic models based on heterotic M theory for which dynamical selection naturally favors the observed value of Q. 相似文献
78.
Estruch T Jaeck J Pardo F Derelle S Primot J Pelouard JL Haidar R 《Optics letters》2011,36(16):3160-3162
We investigate the strong electromagnetic coupling that settles in dual metallic grating structures. This coupling is evidenced to lead to a perfect optical extinction in the transmission spectrum. The behavior of this perfect extinction that strongly depends on the longitudinal space and the lateral displacement between the two gratings can be explained by a simple model that describes the interference between a propagating mode and a couple of evanescent modes. The results show that the electromagnetic transmission of the structure can be tuned by controlling the position of this perfect transmission extinction and thus pave the way to new types of infrared tunable filters. 相似文献
79.
Hitomi Anzai Makoto Ohta Jean-Luc Falcone Bastien Chopard 《Journal of computational science》2012,3(1-2):1-7
A modern technique to treat cerebral aneurysms is to insert a flow diverter in the parent artery. In order to produce an optimal design of such devices, we consider a methodology combining simulated annealing optimization and lattice Boltzmann simulations. Our results surpass, in terms of stent efficiency, those obtained in the recent literature with an other optimization method. Although our approach is still in 2D, it demonstrates the potential of the method. We give some hint on how the 3D cases can be investigated. 相似文献
80.