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61.
Daniele Simoni Giuseppe GianniniPier Giovanni Baraldi Romeo RomagnoliMarinella Roberti Riccardo RondaninRiccardo Baruchello Giuseppina GrisoliaMarcello Rossi Danilo MirizziFrancesco Paolo Invidiata Stefania GrimaudoManlio Tolomeo 《Tetrahedron letters》2003,44(14):3005-3008
A double Suzuki cross-coupling protocol has been devised as a practical route to a variety of terphenyls. Good chemoselectivity was observed. Unsymmetrically substituted triphenylenes were also easily prepared. 相似文献
62.
Giuseppina Masotti Biggiogero 《Milan Journal of Mathematics》1966,36(1):101-142
This lecture shows synthetically the developments of the researches on the Hessian of an algebraic hypersurface ofd dimensions, with a particular view of the plane case (d = 2), and points out several solved and unsolved problems on this subject. 相似文献
63.
Sans résumé 相似文献
64.
Vito Di Noto Lucia A. Magrì Maria Viviani Carla Marega Antonio Marigo Roberto Zannetti 《Journal of chemical crystallography》1992,22(1):59-64
FT-IR Spectroscopy with total attenuated reflectance (ATR) was used for the quantitative determination of ethyl formate coordinated in inorganic matrices such as magnesium chloride. The spectra were recorded directly on solutions obtained by dissolving the inorganic Ziegler-Natta supports in water. The method proposed is sensitive and rapid and appears to be very reliable when compared with other methods, such as solvent extraction followed by gaschromatographic or thermogravimetric analysis. 相似文献
65.
Giuseppina Castronuovo Vittorio Elia Filomena Velleca 《Journal of solution chemistry》1996,25(1):51-59
Enthalpies of dilution of binary and ternary aqueous solutions containing L-and D-proline, cis-L- and cis-D-4-hydroxy proline, trans-L-4-hydroxy proline, have been determined by flow calorimetry at 25°C. Pairwise self-and cross-interaction coefficients of the virial expansion of the excess enthalpies were evaluated. They are positive for solutions of unsubstituted prolines. On the contrary, upon the introduction of a hydroxy group, they become negative, reaching the largest value for the cis-L-lcis-D-4-hydroxy proline system. The results are interpreted in terms of preferential configurations, stabilized by interactions between the hydrophilic groups. 相似文献
66.
Giuseppina Conti Giuseppe Minoni Giuseppe Zerbi 《Journal of Molecular Structure》1984,118(3-4):237-243
Contrary to previous literature reports, crystallisation of behenic and lignoceric acids from warm acetone is found to give the crystalline modification E. The phase transition from E to the more stable C form was studied with Fourier Transform Infrared Spectroscopy. The structural evolution with temperature through the phase transition is discussed. 相似文献
67.
Giuseppe Chidichimo Marcello Longeri Giuseppina Menniti Giovanni Romeo Alida Ferlazzo 《Magnetic resonance in chemistry : MRC》1984,22(1):52-54
The ring mobility of some 1,5-benzodiazepine-2,4-diones and 1,4-benzodiazepin-2-one has been investigated by the temperature dependence of their 1H NMR spectra. The activation parameters have been obtained, and the influence of N-1 substitution on the ring mobility is discussed, taking into account previously reported data for similar compounds. 相似文献
68.
Guido Barone Giuseppina Castronuovo Pompea Del Vecchio Vittorio Elia Maria Teresa Tosto 《Journal of solution chemistry》1988,17(10):925-936
The excess enthalpies of ternary aqueous solutions of biuret with four aliphatic alcohols or four isomeric pentoses have been determined by flow microcalorimetry at 25°C. The coefficients of the virial expansion of the excess enthalpies have been evaluated and compared with those already reported for urea and thiourea with the same alcohols and pentoses used here. For biuret-alcohol systems, the cross coefficients are positive and depend on the length and branching of the alkyl chain of the alcohols. On the contrary, they are negative for biuret-pentose systems. Hence, biuret, as urea and thioura, is able to differentiate the behavior of families of solutes characterized by the same functional groups. The results are interpreted in terms of the relative stabilities of the hydration cospheres of predominantly hydrophobic or predominantly hydrophilic cosolutes. However, hypotheses about the hydration cospheres of the saccharides, which are more complex than those used previously, seem to be necessary to rationalize their complete behavior in water. 相似文献
69.
A multigrid scheme for the solution of constrained optimal control problems discretized by finite differences is presented. This scheme is based on a new relaxation procedure that satisfies the given constraints pointwise on the computational grid. In applications, the cases of distributed and boundary control problems with box constraints are considered. The efficient and robust computational performance of the present multigrid scheme allows to investigate bang-bang control problems.AMS Subject Classification: 49J20, 65N06, 65N12, 65N55Supported in part by the SFB 03 “Optimization and Control” 相似文献
70.
Winfried Leidemann Victor D. Efros Giuseppina Orlandini Edward L. Tomusiak 《Few-Body Systems》2010,47(3):157-165
The threshold transverse response functions R T (q, ω) for 3He and 3H are calculated using the AV18 nucleon–nucleon potential, the UrbanaIX three-body force, and the Coulomb potential. Final states are completely taken into account via the Lorentz integral transform technique. Consistent two-body π- and ρ-meson exchange currents as deduced using the Arenhövel-Schwamb technique are included. The convergence of the method is shown and a comparison of the corresponding MEC contribution is made to that of a consistent MEC for the meson theoretical r-space BonnA potential. The response R T is calculated in the threshold region at q = 174, 324, and 487 MeV/c and compared with available data. The strong MEC contributions in the threshold region are nicely confirmed by the data at q = 324 and 487 MeV/c although some differences between theoretical and experimental results remain. A comparison is also made with other calculations, where the same theoretical input is used. The agreement is generally rather good, but leaves also some space for further improvement. 相似文献