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1.
CV Tomy D Pal SS Banerjee S Ramakrishnan AK Grover S Bhattacharya MJ Higgins G Balakrishnan McK Paul 《Pramana》2002,58(5-6):925-935
The weakly pinned single crystals of the hexagonal 2H-NbSe2 compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order-disorder
transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of
the peak effect phenomenon in three crystals of 2H-NbSe2, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of
a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability
effects and pinning. 相似文献
2.
In subnormal glow discharge under d.c. excitation at different pressure in a varying transverse magnetic field (0 to 30 G)
some measurements have been carried out for various initial average tube currents. The voltage across the discharge increases
and average tube current and residual current decreases in the magnetic field. With the help of Beckman’s expression [4] for
the axial field and the electron density distribution in a transverse magnetic field the observed variation of current and
voltage can be satisfactorily explained. The variation of axial electric field with transverse magnetic field can be represented
to a fair degree of accuracy by the derived equation. The behaviour of residual current with magnetic field has been observed
in these oscillations. 相似文献
3.
An integral equation formulation for buoyancy-driven convection problems is developed and illustrated. Buoyancy-driven convection in a bounded cylindrical geometry with a free surface is studied for a range of aspect ratios and Nusselt numbers. The critical Rayleigh number, the nature of the cellular motion, and the heat transfer enhancement are computed using linear theory. Green's functions are used to convert the linear problem into linear Fredholm integral equations. Theorems are proved which establish the properties of the eigenvalues and eigenfunctions of the linear integral operator which appears in these equations. 相似文献
4.
Organocatalytic,Asymmetric Eliminative [4+2] Cycloaddition of Allylidene Malononitriles with Enals: Rapid Entry to Cyclohexadiene‐Embedding Linear and Angular Polycycles
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Dr. Nicoletta Brindani Dr. Gloria Rassu Dr. Luca Dell'Amico Dr. Vincenzo Zambrano Dr. Luigi Pinna Dr. Claudio Curti Dr. Andrea Sartori Prof. Dr. Lucia Battistini Prof. Dr. Giovanni Casiraghi Prof. Dr. Giorgio Pelosi Dr. Daniela Greco Prof. Dr. Franca Zanardi 《Angewandte Chemie (International ed. in English)》2015,54(25):7386-7390
A direct aminocatalytic synthesis has been developed for the chemo‐, regio‐, diastereo‐, and enantioselective construction of densely substituted polycyclic carbaldehydes containing fused cyclohexadiene rings. The chemistry utilizes, for the first time, remotely enolizable π‐extended allylidenemalononitriles as electron‐rich 1,3‐diene precursors in a direct eliminative [4+2] cycloaddition with both aromatic and aliphatic α,β‐unsaturated aldehydes. The generality of the process is demonstrated by approaching 6,6‐, 5,6‐, 7,6‐, 6,6,6‐, and 6,5,6‐fused ring systems, as well as biorelevant steroid‐like 6,6,6,6,5‐ and 6,6,6,5,6‐rings. A stepwise reaction mechanism for the key [4+2] addition is proposed as a domino bis‐vinylogous Michael/Michael/retro‐Michael reaction cascade. The utility of the malononitrile moiety as traceless activating group of the dicyano nucleophilic substrates is demonstrated. 相似文献
5.
Biavardi E Battistini G Montalti M Yebeutchou RM Prodi L Dalcanale E 《Chemical communications (Cambridge, England)》2008,(14):1638-1640
We report here the monitoring of reversible guest inclusion in phosphonate cavitands through a large increase in luminescence intensity caused by the modulation of the exoergonicity of an electron-transfer reaction. 相似文献
6.
Andrea Sartori Lucia Battistini Gloria Rassu Giovanni Casiraghi 《Tetrahedron》2008,64(51):11697-11705
The direct Mukaiyama-Michael addition of vinylogous tetramate donors to a number of different Michael acceptors has been easily executed, by employing the TMSOTf/Et3N mixture as soft Lewis acid/base promoter agent. Richly functionalized, highly manipulable γ-substituted pyrrolinone products were practically synthesized in acceptable to excellent yields, and with diastereoselectivities heavily relying upon the substituent at the nitrogen atom of the pyrrolinone donor. 相似文献
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Carlo Battistini Cosimo Scarafile Maurizio Foglio Giovanni Franceschi 《Tetrahedron letters》1984,25(22):2395-2398
A new ring closure by carbonyl-carbonyl reductive coupling is utilized in the synthesis of penem and carbapenem nuclei. 相似文献
10.
L. Liebermann F. Selmi A. Moriggia und A. Battistini 《Fresenius' Journal of Analytical Chemistry》1877,16(1):141-144
Ohne Zusammenfassung 相似文献