نتایج جستجو برای: 27al and 35cl nqr

تعداد نتایج: 16827433  

2014
Frank Lehmann-Horn Karin Jurkat-Rott

Materials and Methods: All examinations were performed with ethical review board approval; written informed consent was obtained from all volunteers. Seven examinations each of brain and muscle in healthy volunteers and four examinations of patients were performed. Two patients with histologically confirmed glioblastoma multiforme underwent brain imaging. 35Cl MR and 35Cl inversion-recovery (IR...

Journal: :Physical chemistry chemical physics : PCCP 2016
David A Hirsh Aaron J Rossini Lyndon Emsley Robert W Schurko

In this work, we show how to obtain efficient dynamic nuclear polarization (DNP) enhanced 35Cl solid-state NMR (SSNMR) spectra at 9.4 T and demonstrate how they can be used to characterize the molecular-level structure of hydrochloride salts of active pharmaceutical ingredients (APIs) in both bulk and low wt% API dosage forms. 35Cl SSNMR central-transition powder patterns of chloride ions are t...

Journal: :Analytical chemistry 2002
Yingkai Xiao M Hai Lu Chonggeng Zhang Qingzhong Wang Haizheng Wei Aide Sun Weiguo Liu

The factors that affect isotopic measurement of chlorine based on Cs2Cl+ ion by thermal ionization mass spectrometry were studied. Graphite is essential for the emission of Cs2Cl+ ion from CsCl. No Cs2Cl+ ions are detected in the absence of graphite on the filament. The emission of Cs2Cl+ ion and the measured 37Cl/35Cl ratio were affected by different varieties of graphite, the pH value of the ...

2003
BING ZHOU BARBARA L. SHERRIFF FRANCIS TAULELLE GANG WU

Zunyite [Al13Si5O20(OH,F)18Cl] possesses an unusual combination of an Al13O16(OH)24 Keggin structure and a Si5O16 pentamer unit. We used 19F, 27Al, 29Si MAS and 27Al MQMAS NMR spectroscopy of a series of samples with varying Al:Si and F:OH ratios to investigate the degree of atomic order in zunyite. The quadrupole coupling constant (CQ) and asymmetry parameter ( ) obtained from simulations of 2...

2017
N. A. Sergeev M. Paczwa M. Olszewski A. M. Panich

Temperature dependencies of 27Al and 23Na nuclear magnetic resonance spectra and spin-lattice relaxations in mordenite have been studied in static and magic angle spinning regimes. Our data show that the spin-lattice relaxations of the 23Na and 27Al nuclei are mainly governed by interaction of nuclear quadrupole moments with electric field gradients of the crystal, modulated by translational mo...

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