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141.
Zaharie Moldovan Nicolae Palibroda Monica Culea Ioan FeneAn Andrei Hantz 《Journal of mass spectrometry : JMS》1989,24(2):81-85
This paper presents the mass spectra, fragmentation pathways and structures of ions obtained by electron impact from methyl cyclohexyl phosphinomorpholinylamidothioate (1), cyclohexyl phosphonomorpholinylamidochloridothioate (2), cyclohexyl morpholinylamidophosphonothioic acid (3) and O-methyl cyclohexyl phosphonomorpholinylamidothioate (4). The fragmentation pathways and ion structures were established by exact mass determinations on compound 1 and by metastable transitions of all the compounds. 相似文献
142.
Marian Ioan Munteanu 《Monatshefte für Mathematik》2007,150(4):333-342
In this paper we study doubly warped product CR submanifolds in locally conformal K?hler manifolds, and we found a B.Y. Chen’s type inequality for the second fundamental
form of these submanifolds.
Beneficiary of a CNR-NATO Advanced Research Fellowship pos. 216.2167 Prot. n. 0015506. 相似文献
143.
This paper deals with a theoretical (numerical) analysis of the effects that blowing/injection and suction have on the steady mixed convection or combined forced and free convection boundary layer flows over a vertical slender cylinder with a mainstream velocity and a wall surface temperature proportional to the axial distance along the surface of the cylinder. Both cases of buoyancy forces aid and oppose the development of the boundary layer are considered. Similarity equations are derived and their solutions are dependent upon the mixed convection parameter, the non-dimensional transpiration parameter and the curvature parameter, as well as of the Prandtl number. Dual solutions for the previously studied mixed convection boundary layer flows over an impermeable surface of the cylinder are shown to exist also in the present problem for aiding and opposing flow situations. 相似文献
144.
Material symmetries of elasticity tensors 总被引:1,自引:0,他引:1
145.
146.
Let H be a real Hilbert space, :H [0, + ] a proper l.s.c., convex function with Lk:={u H; u2 + (u) k} compact for every k > 0, let > 0 be a given constant and
. We prove an existence result for strong solutions to a class of functional differential equations of the form
相似文献
147.
Ioan Gavrea 《Results in Mathematics》1996,30(1-2):55-66
In this paper we give positive answers to some problems posed by H.Gonska, respectively A.Lupa?. We show here that there exist positive linear operators H n : C[0, 1] → πn satisfying 相似文献
148.
RR'SbCl (1) and RR'BiCl (2) [R = 2-(Me(2)NCH(2))C(6)H(4), R' = CH(Me(3)Si)(2)] form by the reaction of R'ECl(2) (E = Sb, Bi) with RLi. The reaction of 1 with LiAlH(4) and metalation with n-BuLi gives RR'SbH (3) and RR'SbLi.2THF (4) (THF = tetrahydrofuran). Transmetalation of 4 with sodium tert-butoxide in the presence of TMEDA (TMEDA = tetramethylethylenediamine) leads to RR'SbNa.TMEDA (5). Structural analyses by (1)H NMR in C(6)D(6), C(6)D(5)CD(3), or (CD(3))(2)SO with a variation of the temperature (1, 2, 4, and 5) and by single-crystal X-ray diffraction (1, 2, 4, and 5) revealed the intramolecular coordination of the pendant Me(2)N group on the pnicogen centers in 1 and 2 and on Li or Na in 4 or 5. The variable-temperature (1)H NMR spectra of the hydride 3 in C(6)D(6), C(6)D(5)CD(3), or (CD(3))(2)SO show that the pyramidal configuration on antimony is stable up to 100 degrees C, whereas inversion at the nitrogen is not prevented by internal coordination even at -80 degrees C. The crystals of 1, 2, 4, and 5 consist of discrete molecules with the Sb and Bi atoms in an approximately Psi-trigonal-bipyramidal environment in the cases of 1 and 2 and in a pyramidal environment in the cases of 4 and 5. Crystal data for 1: triclinic, space group Ponemacr;, a = 7.243(4) A, b = 10.373(3) A, c = 15.396(5) A, alpha = 79.88 degrees, beta = 78.27 degrees, gamma = 71.480(10) degrees, V = 1066.2(7) A(3), Z = 2, R = 0.0614. 2: monoclinic, space group P2(1)/n, a = 10.665(2) A, b = 14.241(2) A, c = 14.058(2) A, beta = 90.100(10) degrees, V = 2135.1(6) A(3), Z = 4, R = 0.049. 4: monoclinic, space group P2(1)/n, a = 11.552(2) A, b = 16.518(3) A, c = 15.971(5) A, beta = 96.11(2) degrees, V = 3030.2(12) A(3), Z = 4, R = 0.0595. 5: monoclinic, space group P2(1)/n, a = 9.797(2) A, b = 24.991(5) A, c = 14.348(3) A, beta = 94.98(3) degrees, V = 3499.66(12) A(3), Z = 4, R = 0.0571. The dissociation of the intramolecular N-pnicogen bond and inversion at the nitrogen occurs when solutions of 1 or 2 in C(6)D(6) or C(6)D(5)CD(3) are heated above 25 or 30 degrees C. 1 and 3-5 are stable with respect to inversion of the configuration at the antimony in C(6)D(6), C(6)D(5)CD(3), or (CD(3))(2)SO up to 160 degrees C. Bismuth inversion, probably via the edge mechanism, is observed in solutions of 2 in (CD(3))(2)SO at 45 degrees C but not in C(6)D(5)CD(3) below 125 degrees C. 相似文献
149.
Rusu Mihai Lucian Marutoiu Constantin Sandu Ion Tita Dumitru Gogoasa Ioan Barbu Constantin-Horia Popescu Andreea 《平面色谱法杂志一现代薄层色谱法》2007,20(2):139-140
JPC – Journal of Planar Chromatography – Modern TLC - Samples of clove, nutmeg, and cinnamon have been extracted by maceration with ethanol for 24 h and with aqueous ethanol 48 h.... 相似文献
150.
Stela DrÎgan Silvia Ioan I. Petrariu M. Dima 《Journal of polymer science. Part A, Polymer chemistry》1985,23(5):1267-1281
The macromolecular chain conformational state during the amination of chloromethylated polystyrene (CMPS) with two aliphatic amines, namely methyl(2-hydroxyethyl)amine (MHEA) and N,N-dimethyl(2-hydroxypropyl)amine (DM2HPA), has been studied. Viscosimetric and light scattering measurements were performed during reactions in binary solvent mixtures. The observed kinetic deviations have been related with the conformational transformations of the macromolecular chain. 相似文献
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