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61.
The biological activity of a series of structurally diverse 3-isothiazolones (1) has been assessed by evaluating the minimum inhibitory concentration required to inhibit the growth of E. Coli. The structure and electronic properties of these derivatives have been calculated using both semi-empirical and ab initio molecular orbital methods. Multi-linear regression analysis shows no correlation between the experimental activity of the 3-isothiazolones and either the calculated geometries, electronic properties, or the frontier orbital energies of these derivatives, but a reasonable relationship is found with other parameters including their calculated solvation energies, suggesting that diffusion may play an important role in their mode of action. 相似文献
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Ram K. Agarwal Prakash C. Jain Miss Veena Kapur Miss Sunita Sharma Anant K. Srivastava 《Transition Metal Chemistry》1980,5(1):237-239
Summary Crystalline thorium(IV) chelates with monoN-oxides of 2,2-bipyridine (bipyNO) and 1,10-phenanthroline (phenNO), ThX4 · 2L (X = Cl, Br, NO3 or NCS) and ThX4 · 3L (X = I or ClO4, and I = bipyNO or phenNO) have been synthesised and characterized on the basis of i.r. spectra, molar conductance, molecular weights, t.g.a. and d.t.a. data. All the complexes are weakly diamagnetic and contain bipyNO and phenNO bonded to thorium(IV) through nitrogen and oxygen. The coordination number of thorium(IV) varies from six to twelve depending on the nature of the anions.Author on leave from L. R. Postgraduate College, Sahibabad (Ghaziabad) and to whom all correspondence should be directed. 相似文献
64.
Polymethyl methacrylate has been obtained at 40° with a VOCl3-AlEt3 catalyst in the presence of various amounts of basic additives, at a ratio of 1·5 of Al/V. The configuration of the polymers was affected by the presence of additives. An increase in the percentage of syndiotacticity and no alteration of the stereoblock structure were indicated by i.r. and n.m.r. The effects of additives on the formation of syndiotactic structures are discussed on the basis of their electron donating powers. 相似文献
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S. L. Malhotra A. B. Deshpande S. L. Kapur 《Journal of polymer science. Part A, Polymer chemistry》1968,6(1):193-203
The polymerization of styrene with two catalyst systems consisting of Al(C2H5)3 in combination with ZrCl4 or ZrCl3 has been studied. The rate of polymerization with catalyst concentration was first-order with ZrCl4 system and second-order with ZrCl3 system, but at higher catalyst concentrations in both cases, the rate progressively decreases and finally attains a low value. The rate of polymerization is, however, proportional to the square of the monomer concentration in both the cases. The overall energy of activation was 10.9 kcal./mole and 6.45 kcal./mole in these systems. The polymers obtained with ZrCl4 were of lower molecular weights as compared to those obtained with ZrCl3. The polymers in both the cases had amorphous character. 相似文献
67.
J. N. Kapur 《Proceedings Mathematical Sciences》1969,69(4):201-211
In a recent paper, we defined entropy of order α and type β. For α = 1, it reduces to Renyi’s2 entropy of order α, while for α = 1, β= 1 and for a complete probability distribution, it reduces to Shannon’s definition of entropy. In this paper we have studied some properties of this generalised entropy. We have also discussed the variability of Renyi’s entropy in the continuous case with co-ordinate systems and invariance of transinformation of order α and type β for linear transformations. 相似文献
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