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91.
A general and efficient procedure for the stereoselective synthesis of (E)-(1-propenyl)phenyl esters from readily accessible allylphenols has been developed. The process involves a two-step sequence consisting of the initial acylation of the allylphenols with an acid chloride, followed by catalytic CC bond isomerization in the resulting allylphenyl esters. The latter step was performed in methanol at 80 °C using catalytic amounts (0.5 mol %) of the commercially available bis(allyl)-ruthenium(IV) dimer [{RuCl(μ-Cl)(η3:η3-C10H16)}2] (C10H16=2,7-dimethylocta-2,6-diene-1,8-diyl). Reactions proceeded in high yields (68–93%) and short times (4–9 h) with complete E-selectivity. 相似文献
92.
We consider a newsvendor who earns a revenue from the sales of her product to end users as well as from multiple advertisers paying to obtain access to those end users. We study the optimal decisions of a price-taking and a price-setting newsvendor when the advertisers have private information about their willingness to pay. We focus on the impact of the number of advertisers on the newsvendor’s optimal decisions. We find that regardless of the number of advertisers, the newsvendor may exclude advertisers with a low willingness to pay and distort the price and inventory from their system-efficient levels to screen the advertisers. Moreover, the newsvendor’s decision to exclude an advertiser is based exclusively on that advertiser’s characteristics, and the newsvendor’s optimal decision thus reveals independence among the advertisers. Nonetheless, the profits of the newsvendor and the advertisers also display network effects as both increase in the number of advertisers. Finally, our numerical results show that the newsvendor prefers an equivalent single advertiser to multiple advertisers due to the pooling effect. 相似文献
93.
Conducting and chiral [Ni(dmit)(2)] dithiolene salts were obtained by electrocrystallization of the radical [n-Bu(4)N][Ni(dmit)(2)] salt in the presence of chiral, enantiopure trimethylammonium cations. Three different cations were investigated, namely, (R)-Ph(Me)HC*-NMe(3)(+), (S)-((t)Bu)(Me)HC*-NMe(3)(+), and (S)-(1-Napht)MeHC*-NMe(3)(+), noted (R)-1, (S)-2, and (S)-3. Salts of 1:3 stoichiometry were obtained with (R)-1 and (S)-2, formulated as [(R)-1][Ni(dmit)(2)](3) and [(S)-2][Ni(dmit)(2)](3)·(CH(3)CN)(2). They both crystallize in the P2(1)2(1)2(1) chiral space group, with three crystallographically independent complexes exhibiting different oxidation degrees. Another salt with 2:5 stoichiometry was isolated with (S)-3. The semiconducting character of the three salts (σ(RT) = 20-30 × 10(-3) S cm(-1)) finds its origin in a strong electron localization, favored by the large number of crystallographically independent [Ni(dmit)(2)] complexes in these chiral structures and their association into weakly interacting dimeric or trimeric motifs. Racemic salts with the same cations, obtained only with difficulties with the tert-butyl-containing (rac)-2 cation, afforded similar trimerized structures. The observed unusual stoichiometry and strong charge localization is tentatively assigned to the size and anisotropic charge distribution of the cations. 相似文献
94.
Maxwell D. Cummings Tse‐I Lin Lili Hu Abdellah Tahri David McGowan Katie Amssoms Stefaan Last Benoit Devogelaere Marie‐Claude Rouan Leen Vijgen Jan Martin Berke Pascale Dehertogh Els Fransen Erna Cleiren Liesbet vanderHelm Gregory Fanning Kristof VanEmelen Origne Nyanguile Kenny Simmen Pierre Raboisson Sandrine Vendeville 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2012,124(19):4715-4718
95.
A. De Giacomo O. De Pascale 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1405-1407
In this work final results on TiO2 film deposition by Plasma Assisted Pulsed Laser Deposition (PAPLD) with an rf biased substrate are presented. In previous work it has been shown that PAPLD is an improvement over conventional PLD for the elimination of particulates in high refractive index thin film deposition. This paper will give a comparison between conventional PLD and PAPLD on the stoichiometry, morphology, and optical properties of deposited TiO2 films. It will be demonstrated that oxygen rf discharge during the PLD process makes incorporation of oxygen into the depositing films extremely effective. This effect of the rf discharge allows operation of the PLD process at a lower oxygen background pressure while enhancing the deposition rate. Also, the production of a good quality TiO2 film by PAPLD using a pure metal titanium target will be shown. PACS 79.20.Ds; 52.80.Pi 相似文献
96.
O. De Pascale C. Esposito M. Lepore P. Boffi M. Gaudio M. Vilnio 《Optics and Lasers in Engineering》1989,10(2)
Plane-polarized CO2 laser beams can be successfully employed in controlled surface temperature laser heat treating in order to improve the coupling between radiation and steel. The coupling efficiency has been quantitatively determined by means of a simple energy balance model, by using a medium-power CO2 laser. In this way, the angle at which the best coupling can be obtained has also been singled out. Moreover, some heat treatments performed with a high power laser beam obliquely impinging on medium carbon steel samples have confirmed that controlled surface temperature laser heat treating can be completely free of the problems concerning the use of coatings generally employed. 相似文献
97.
Let X be a Banach space of differentiable functions and A: XX be a superposition operator. We consider for A the conditions
相似文献
98.
Bachir Douara Yannick J. Esvan Elisabeth Pereira Francis Giraud Yulia L. Volodina Dmitry N. Kaluzhny Alexander A. Shtil Fabrice Anizon Pascale Moreau 《Tetrahedron》2018,74(8):892-901
Pyrazole analogs of the staurosporine aglycon K252c were recently described as potent inhibitors of the three Pim protein kinase isoforms. To evaluate the impact of the introduction of a sugar moiety on the biological activities of this heterocyclic scaffold, four new glucosylated pyrazole analogs of K252c were synthesized. Their biological evaluation demonstrated that most active compounds 11 and 19 substituted by a β-d-glucosyl moiety at N12 or N13 positions exhibited antiproliferative activities toward HCT116 cells. 相似文献
99.
100.
Pascale Bénézeth Donald A. Palmer David J. Wesolowski 《Journal of solution chemistry》1997,26(1):63-84
The three molal dissociation quotients for citric acid were measured potentiometrically with a hydrogen-electrode concentration
cell from 5 to 150°C in NaCl solutions at ionic strengths of 0.1, 0.3, 0.6, and 1 molal. The molal dissociation quotients
and available literature data at infinite dilution were fitted by empirical equations in the all-anionic form involving an
extended Debye-Hückel term and up to five adjustable parameters involving functions of temperature and ionic strength. This
treatment yielded the following thermodynamic quantitites for the first dissociation equilibrium at 25°C: logK
1a=−3.127±0.002, ΔH
1a
o
=4.1±0.2 kJ-mol−1, ΔS
1a
o
=−46.3±0.7 J-K−1-mol−1, and ΔCp
1a
o
=−162±7 J-K−1-mol−1; for the second acid dissociation equilibrium at 25°C: logK
2a
=−4.759±0.001, ΔH
2a
o
=2.2±0.1, ΔS
2a
o
=−83.8±0.4, and ΔCp
2a
o
=−192±15, and for the third dissociation equilibrium at 25°C: logK
3a=−6.397±0.002, ΔH
3a
o
=−3.6±0.2, ΔS
3a
o
=−134.5±0.7, and ΔCp
3a
o
=−231±7. 相似文献
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