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Nonlinear Dynamics - Quantum features of time-dependent molecular interactions are investigated by introducing a time-varying Hamiltonian that involves a generalized non-central potential.... 相似文献
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Novel and Stereospecific Synthesis of (2S)‐3‐(2,4,5‐Trifluorophenyl)propane‐1,2‐diol from D‐Mannitol 下载免费PDF全文
Derya Aktaş Meryem Fıstıkçı Özlem Gündoğdu Hasan Seçen M. Fethi Şahin Ramazan Altundaş Yunus Kara 《Helvetica chimica acta》2015,98(8):1127-1131
A stereospecific synthesis of (2S)‐3‐(2,4,5‐trifluorophenyl)propane‐1,2‐diol from D ‐mannitol has been developed. The reaction of 2,3‐O‐isopropylidene‐D ‐glyceraldehyde with 2,4,5‐trifluorophenylmagnesium bromide gave [(4R)‐2,2‐dimethyl‐1,3‐dioxolan‐4‐yl](2,4,5‐trifluorophenyl)methanol in 65% yield as a mixture of diastereoisomers (1 : 1). The Ph3P catalyzed reaction of the latter with C2Cl6 followed by reduction with Pd/C‐catalyzed hydrogenation gave (2S)‐3‐(2,4,5‐trifluorophenyl)propane‐1,2‐diol with >99% ee and 65% yield. 相似文献
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The aim of the present paper is to define and study semi-slant \(\xi ^\perp \)-Riemannian submersions from Sasakian manifolds onto Riemannian manifolds as a generalization of anti-invariant \(\xi ^\perp \)-Riemannian submersions, semi-invariant \(\xi ^\perp \)-Riemannian submersions and slant Riemannian submersions. We obtain characterizations, investigate the geometry of foliations which arise from the definition of this new submersion. After we investigate the geometry of foliations, we obtain necessary and sufficient condition for base manifold to be a locally product manifold and proving new conditions to be totally umbilical and totally geodesicness, respectively. Moreover, some examples of such submersions are mentioned. 相似文献
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N‐vinylimidazole (VIM), and phenacyl methacrylate (PAMA) copolymerized with different feed ratios using 1,4‐dioxane as a solvent and α,α'‐azobisisobutyronitrile (AIBN) as an initiator at 60°C. Structure and composition of copolymers for a wide range of monomer feed were determined by elemental analysis (content of N for VIM‐units) and by Fourier transform infrared spectroscopy through recorded analytical absorption bands for VIM (670 cm?1 for C‐N of imidazole ring) and PAMA (1730 cm?1 for C?O of ester group) units, respectively. Monomer reactivity ratios for VIM (M1)‐PAMA (M2) pair were determined by the application of conventional linearization methods such as Fineman‐Ross (F‐R) and Kelen‐Tüdös (KT) and a nonlinear error invariable model method using a computer program RREVM. The molecular weights (w and n) and polydispersity indices of the polymers were determined using gel permeation chromatography (GPC). Thermal behaviors of copolymers with various compositions were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Also, the apparent thermal decomposition activation energies (ΔEd) were calculated by Ozawa method using the SETARAM Labsys TGA thermobalance. The antibacterial and antifungal effects of polymers were also tested on various bacteria, fungi and yeast. 相似文献
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Ramazan Turkmen Vehbi E. Paksoy Fuzhen Zhang 《Linear algebra and its applications》2012,437(6):1305-1316
We show some majorization inequalities and apply them to derive norm, eigenvalue, singular value, and trace inequalities of matrices. We also present a generalization and a different proof of a recent result on majorization concerning partitioned Hermitian positive semidefinite matrices. 相似文献
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Seven [2.2.1] bridged alkenes were cleaved to the corresponding dialdehyde products by neutral heterogenous oxidation with KMnO4-CuSO4.5H2O. While endo, endo-dimethyl bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, [2.2.2] bridged alkene, gave the corresponding α-hydroxy ketone, endo, endo-dimethyl bicyclo[3.2.2]non-8-ene-6,7-dicarboxylate afforded a diketone product. 相似文献
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