摘要: The ZnBr2-catalyzed (4 + 2) cycloaddition of Danishefsky's diene (1) to variously N-protected D-alaninals (2) was studied, and a large difference between the N-protecting groups replacing either one or two amino protons was observed....
seniority scheme for a simple system of protons and neutrons In the framework of a simple model of Z protons and N neutrons in single shells respectively, we compare the ground state energies given by the stretch sch... V Gillet,J Raynal - 《Nuclear Physics》 被引量: 9发表: 1968年 ...
The number of electrons is balanced by the number of protons in both blocks. Thus, neither block has any net charge. However, a single semiconductor crystal manufactured with P-type material at one end and N-type material at the other in Figure below (b) has some unique properties. The ...
Also the protons in positions 3 and 5 of the pyridine ring gave one doublet resonance in the aromatic region. This suggests either a symmetrical (Se,N,Se-monometallic triconnective) coordination in the case of complexes 5–7 or a fast dynamic process, at room temperature, for compound 8,...
We study the competition between $\\ensuremath{\\alpha}$-type and conventional pair condensation in the ground state of nuclei with neutrons and protons in... N Sandulescu,D Negrea,CW Johnson - 《Physical Review C》 被引量: 10发表: 2012年 Proton-Neutron Pairing Correlations in the Self-...
Analysis of NOE interactions between protons of the dye and the oligonucleotides show the phenazinium polycyclic system to intercalate between G-7 and C-8 residues of the octanucleotide. 展开 被引量: 4 年份: 1992 收藏 引用 批量引用 报错 分享 ...
Considering that the amide group is more readily protonated than the hydroxyl group31 and that two protons repel each other due to electrostatic repulsion, we built two models, both of which have one H+ on PA and a second H+ on the distal N-acetylglucosamine (GlcNAc) of either α1-3 (...
one finds that the14N nuclei of NH groups have intra-residue dipole-dipole couplings with HN, Hα, Hβand Hγside-chain protons of ca. 8, 1, 1 and 0.5 kHz, respectively. Other inter-residue couplings ranging from ca. 0.5 down to 0.15 kHz may also be identified. Relevant intra- and...
In organic chemistry, N,N-Diisopropylethylamine is used as a base. Since the nitrogen centre is isolated by an ethyl group and the two isopropyl groups, It can bind to protons. The compound is, therefore, a base similar to 2,2,6,6-tetramethylpiperidine, but a poor nucleophile, a blend...
Neutrino produced in a chain of nuclear reactions in the Sun starting from the fusion of two protons for the first time has been detected in a real-time de... OY Smirnov,M Agostini,S Appel,... - ФизикаЭлемнтарныхчастициАтомногоЯдра 被引量...