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1.
An electrolytic device for decomposition of water has been developed which readily gives hydrogen and oxygen for isotopic measurement with a mass spectrometer. A 20-mul sample can be decomposed quantitatively in 10 min with good reproducibility. The results produced are comparable with those obtained by reduction with uranium. 相似文献
2.
Rashid A. Zeineh George Kyriakidis A. Rashid Bhatti 《Applied biochemistry and biotechnology》1986,13(2):111-117
Virion polypeptides (35 S), methionine-labeled and purified by CsCl gradient centrifugation, were separated by SDS-gel electrophoresis. Analysis of their band pattern was performed by scanning the images of the SDS-gels shown on a 35-mm slide. The densitometric tracings revealed the presence of 17 protein bands, although only 15 of them were visible to the naked eye. The high sensitivity and resolving capacities of the soft-laser scanning densitometer enabled us to detect trace amounts of protein bands separated in SDS-gels and to obtain a resolution compatible to that of electrophoresis. Fourfold electronic amplification of the densitometric tracings, produced by a computer, generated new information regarding the pattern of the electrophoregram. The facility to amplify peaks of importance is particularly advantageous when faint or overlapping protein bands revealed on a gel are assessed. 相似文献
3.
T. Jabbar M. S. Subhani K. Khan A. Rashid S. D. Orfi A. Y. Khan 《Journal of Radioanalytical and Nuclear Chemistry》2003,258(1):143-149
A study on the concentration of natural and fallout radionuclides in environmental samples collected from different localities of Islamabad was performed. For the determination of gamma-emitters such as 238U, 232Th, 40K and 137Cs high purity germanium (HPGe) detector was used while for the analysis of 90Sr, a beta-emitter, liquid scintillation counting system was used. The indoor absorbed dose rate was measured by a CaF2 : Dy thermoluminescence detector. Other radiation parameters were also determined to evaluate the radiation hazard. All the results were well within the permissible limits showing that there is no radiation hazard in the environment of Islamabad. 相似文献
4.
5.
Abdou O. Abdelhamid Cyril Prknyi S. M. Khaledur Rashid Winston D. Lloyd 《Journal of heterocyclic chemistry》1988,25(2):403-405
Substituted 2-arylbenzimidazoles, 2-arylbenzoxazoles and 2-arylbenzothiazoles were obtained in good yield by the reaction of hydroximoyl chlorides with ortho-substituted aromatic amines. The benzo moiety of the benzimidazoles was shown by nmr to be symmetrical, indicating that the N-H group proton of the imidazole ring is exchanging with the water protons in the DMSO-d6 solvent. 相似文献
6.
K. Rashid B. Fricke J. H. Blanke J. P. Desclaux 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1988,11(2):99-103
The ground state (J=0) electronic correlation energy of the 4-electron Be-sequence is calculated in the Multi-Configuration Dirac-Fock approximation forZ=4–20. The 4 electrons were distributed over the configurations arising from the 1s, 2s, 2p, 3s, 3p and 3d orbitals. Theoretical values obtained here are in good agreement with experimental correlation energies. 相似文献
7.
In the presence of triethylamine, 2-mercaptobenzoic acid readily adds onto acylhydrazonoyl chlorides (1a-c) (precursors of the reactive nitrile imine 1,3-dipolar species) to afford good yields of the corresponding 2-[(2-oxo-1-arylhydrazonopropan-1-yl)mercapto]benzoic acids (2a-c). The latter acyclic adducts, in THF in the presence of 1,1'-carbonyldiimidazole, undergo intramolecular cyclization involving the activated carboxy and the enol functionality to deliver the respective 2-(N-arylhydrazono)-3-oxobenzothiophenes (3a-c). In the solid state, the latter compounds adopt the (Z)-geometry around the C=N double bond as evidenced by single crystal X-ray structure determination for 3b. 相似文献
8.
Jalal A.?Zahra Bassam Abu?Thaher Mustafa M.?El-Abadelah Hans-Hartwig?OttoEmail author 《Monatshefte für Chemie / Chemical Monthly》2005,136(4):567-570
Summary. Nitrilimines prepared from N-arylhydrazono chlorides reacted with 2-mercaptonicotinic acid yielding the corresponding addition products, 2-[(2-oxo-1-arylhydrazonopropan-1-yl)mercapto] nicotinic acids, which were treated with 1,1-carbonyldiimidazole in THF affording by cyclocondensation the corresponding hitherto unknown 2-arylhydrazono-3-oxothieno[2,3-b]pyridines. 相似文献
9.
Rashid MA Gustafson KR Crouch RC Groweiss A Pannell LK Van QN Boyd MR 《Organic letters》2002,4(19):3293-3296
Poecillastrin A (1), a new polyketide-derived macrolide lactam, was isolated from a deep-water collection of the marine sponge Poecillastra species. The structure of poecillastrin A (1) was assigned using NMR data acquired at 500 MHz with an inverse-detection cryogenic probe and at 800 MHz with a room-temperature probe. 相似文献
10.
Proton NMR was used to study the complexation reaction between silver ion and hexathia-18-crown-6 in a number of binary mixed solvents of dimethyl sulfoxide with acetonitrile and methanol. Formation constants for the resulting 1:1 complexes in different solvent mixtures were determined by computer fitting of the chemical shift-mole ratio data. The influence of solvent composition on the stability of the resulting complex is discussed. The exchange kinetics of Ag+-hexathia-18-crown-6 in 70-30 wt.% dimethyl sulfoxide-acetonitrile and 75-25 wt.% dimethyl sulfoxide-methanol were studied by proton NMR line-shape analysis. In both solvent mixtures, the exchange of thiacrown ether between the free and complexed sites was found to proceed via a dissociative pathway. The exchange rates and the activation parameters E
a, H
, S, and G for the ligand exchange were determined and the influence of solvent properties on these parameters discussed. 相似文献