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941.
S.A. Masti A.K. Sharma P.N. Vasambekar A.S. Vaingankar 《Journal of magnetism and magnetic materials》2006
Magnetization and permeability of polycrystalline ferrites with general formula CdxMg1−xFe2−yCryO4 (x=0, 0.2, 0.4, 0.6, 0.8, 1.0; y=0, 0.05 and 0.10) were studied. Study of saturation magnetization reveals that the Neel's two-sublattice model exists upto x=0.4, for y=0, 0.05 and 0.1 and a three-sublattice model (YK-model) is predominant for x>0.4 and y=0, 0.05 and 0.10. The saturation magnetization and magnetic moment were found to decrease with the increase in Cr3+ contents, which is attributed to the dilution of B–B site interaction. Variation of initial permeability with temperature revealed the long-range ferromagnetic ordering in the compounds with x=0.4. The sample with x?0.4 and y=0, 0.05 and 0.10 showed peaking behavior near Curie temperature, which is attributed to the decrease of anisotropy constant K1 to zero. Low-frequency dispersion of initial permeability suggests domain wall displacement. Addition of Cd2+ resulted in a sharp decrease in Curie temperature. With the addition of Cr3+, initial permeability was found to decrease. 相似文献
942.
We show that the tenure lengths for managers of sport teams follow a power law distribution with an exponent between 2 and 3. We develop a simple theoretical model which replicates this result. The model demonstrates that the empirical phenomenon can be understood as the macroscopic outcome of pairwise interactions among managers in a league, threshold effects in managerial performance evaluation, competitive market forces, and luck at the microscopic level. 相似文献
943.
J. C. Spehner 《Semigroup Forum》1989,39(1):323-334
The main results about automatas and the languages they accept are easily extended to automatas which recognize a family of
languages (Li)iεI of a free monoid, that is to automatas which recognize simultaneously all the languages Li. This generalization enhances the notion of automata of type (p,r) introduced by S. Eilenberg [4].
In a similar way the notion of syntactic monoid of a family of languages extends the notion of syntactic monoid of a language.
This extension is far from being trivial since we show that every finite monoid is the syntactic monoid of a recognizable
partition of a free monoid, though this is false for the syntactic monoids of languages.
相似文献
944.
High-performance liquid chromatography was used to determine cyclosporin A (CsA) concentrations in the serum of kidney transplant patients by rapid-flow fractionation (RFF) followed by silica gel normal-phase high-performance liquid chromatography (HPLC). The extraction of CsA from serum was achieved by RFF using a short diatomaceous earth column eluted with diethyl ether-n-hexane (50:50, v/v). The recovery was more than 80% at concentrations of 50-150 micrograms/l. The concentration of this compound was determined by HPLC using a conventional silica gel column with 3.3 M ammonia solution-ethanol-n-hexane (0.31:10.69:89, v/v) as eluent. Concentration calibration was made on the basis of the peak-height ratio of CsA to CsD as the internal standard. The coefficient of variation of this assay was less than 6.5% and the results were used for the therapeutic drug monitoring of CsA administered to kidney transplant patients. Measurements of the CsA concentrations in 160 serum specimens were also made by conventional radioimmunoassay (RIA) using commercial kits. The data obtained by RIA were on average 2.5 times those obtained by HPLC. Higher values in RIA were observed characteristically with patients with severe disfunction resulting from CsA hepatotoxicity. From the results, it appeared that HPLC rather than RIA provides more precise and reliable values for the concentration of this drug. 相似文献
945.
Correlation between the particles from the proton-nucleus interactions in emulsion at 70 GeV/c is presented through the study of the rapidity gap analysis and compared with the two-particle rapidity correlations. It is observed that the strength of correlation decreases as the size of cluster increases. Asymmetry between the forward and backward components were also studied.Authors are thankful to Prof. K. D. Tolstov, JINR, Dubna, USSR for sending the exposed emulsion plates. Thanks are also due to UGC for financial assistance. We sincerely acknowledge the encouragement from Prof. T. Roy. 相似文献
946.
G. Gargaro F. Gasparrini D. Misiti G. Palmieri M. Pierini C. Villani 《Chromatographia》1987,24(1):505-509
Summary Enantiomers of several sulfoxides and some selenoxides can be easily separated by using a new chiral stationary phase (CSP-DACH-DNB)
containing the 3,5-dinitrobenzoyl derivative of R,R-(-)1,2-diamino-cyclohexane as selector, covalently bonded to the siliceous
matrix. The easy operative conditions and the high enantioselectivity values (α) allow a direct transfer of the analytical
separations to a semi-preparative and preparative scale. 相似文献
947.
948.
949.
This paper presents results of studies on dc electrical conductivity and transference number measurements on potassium bromate
(KBrO3) complexed polyvinyl chloride (PVC) films prepared by solution cast technique. Temperature dependence of dc electrical conductivity
and transference number data indicated the dominance of ion type charge transport in these specimens. The magnitude of conductivity
increased with increase in concentration of the salt and temperature. Using this (PVC + KBrO3) electrolyte, solid-state electrochemical cells were fabricated, and their discharge profiles were studied under a constant
load of 100 kΩ. Several cell profiles such as open circuit voltage, short circuit current, power density, and energy density
associated with these cells were evaluated and were reported. The features of complexation of the electrolytes were studied
by X-ray diffraction and Fourier transform infrared spectroscopy.
Paper presented at the Third International Conference on Ionic Devices (ICID 2006), Chennai, Tamilnadu, India, Dec. 7–9, 2006 相似文献
950.
K Cooper S C Brailsford R Davies 《The Journal of the Operational Research Society》2007,58(2):168-176
Economic evaluation, such as cost effectiveness analysis, provides a method for comparing healthcare interventions. These evaluations often use modelling techniques such as decision trees, Markov processes and discrete event simulations (DES). With the aid of examples from coronary heart disease, the use of these techniques in different health care situations is discussed. Guidelines for the choice of modelling technique are developed according to the characteristics of the health care intervention.The choice of modelling technique is shown to depend on the acceptance of the modelling technique, model ‘error’, model appropriateness, dimensionality and ease and speed of model development. Generally decision trees are suitable for acute interventions but they cannot model recursion and Markov models are suitable for simple chronic interventions. It is further recommended that population based models be used in order to provide health care outcomes for the likely cost, health benefits and cost effectiveness of the intervention. The population approach will complicate the construction of the model. DES will allow the modeller to construct more complex, dynamic and accurate systems but these may involve a corresponding increase in development time and expense. The modeller will need to make a judgement on the necessary complexity of the model in terms of interaction of individuals and model size and whether queuing for resources, resource constraints or the interactions between individuals are significant issues in the health care system. 相似文献