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951.
L Soltés 《Biomedical chromatography : BMC》1992,6(1):43-49
The paper presents results and experience obtained in the isolation of a number of basic polar/non-polar solutes (drugs, their metabolites and structural derivatives) from biological samples by using the separation minicolumns Separcol SI and Separcol SI C18 L/T. The aim was to provide insight into some simple procedures yielding optimal selectivity/specificity of the isolation of the studied solutes either by proper selection of the sorbent or by applying sophisticated elution schemes which use to advantage different properties of the eluents/solvents. 相似文献
952.
953.
954.
G. Tian and S.K. Donaldson formulated a conjecture relating GIT stability of a polarized algebraic variety to the existence of a Kähler metric of constant scalar curvature. In [D3] Donaldson partially confirmed it in the case of projective toric varieties. In this paper we extend Donaldson’s results and computations to a new case, that of reductive varieties.Received: November 2003 Revision: January 2004 Accepted: January 2004 相似文献
955.
956.
We study the system of nonlinear differential equations which expresses the constancy of the algebraic invariants of the Jacobian matrix for smooth vector fields in three-dimensional space. This system is equivalent to the equations of gas dynamics which describe the barochronous motions of a gas (the pressure and density depend only on the time). We present the results of computation of the admissible local Lie group and construction of the general solution of the system. We mention a few new problems that arise here. 相似文献
957.
Magnetization reversal processes by a switching field in single-domain nano-sized magnetic particles in the presence of a small transverse non-static bias field are studied. Applying an oscillating bias field instead of a static field, the reversal time becomes much shorter when the switching field is slightly stronger than the effective anisotropy field. A pulsed bias field of a suitably chosen duration in the nanosecond scale is found to induce a rapid switching, even when the switching field is smaller than the anisotropy field. The dependence of the reversal time on the frequency of an oscillating bias field and the duration of a pulsed bias field are studied. The present work thus complement the earlier studies on switching in the presence of a static bias field. 相似文献
958.
M. I. Oshtrakh O. B. Milder V. A. Semionkin L. I. Malakheeva P. G. Prokopenko 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(3):671-677
Summary Characterization of iron storage proteins in liver and spleen from normal chicken and chicken with lymphoid leukemia in comparison
with human liver ferritin were considered by M?ssbauer spectroscopy (preliminary results). Small differences in M?ssbauer
hyperfine parameters for both normal and lymphoid leukemia chicken liver and spleen were observed. The value of quadrupole
splitting for human liver ferritin was higher than those for chicken tissues. A decrease of iron content in lymphoid leukemia
chicken tissues was also found, however, the reason of this fact (pathology or feeding) was not clear yet. 相似文献
959.
960.
L. N. Dianova T. G. Koksharova N. V. Volkova 《Chemistry of Heterocyclic Compounds》1992,28(3):321-323
Nucleophilic substitution of 5-methylthio- and 5-cyanomethylthio-7-amino-s-triazolo[1,5-c]pyrimidines has been carried out using sodium hydroxide, ammonia, hydrazine hydrate, and four amines. The cyanomethyl group is particularly reactive under these conditions and 5-cyanomethylthiotriazolopyrimidine can be used to functionalize this heterocycle.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 382–385, March, 1992. 相似文献