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1.
Chandrachood Pranav S. Jadhav Amol R. Garud Dinesh R. Deshpande Nirmala R. Puranik Vedavati G. Kashalkar Rajashree V. 《Research on Chemical Intermediates》2020,46(12):5219-5230
Research on Chemical Intermediates - A series of quinoxaline derivatives were efficiently synthesized by convenient and simple procedure in excellent yields using 1 wt.% of titanium silicate (TS-1)... 相似文献
2.
In this and subsequent papers we will show that several algorithms for the isotonic regression problem may be viewed as active set methods. The active set approach provides a unifying framework for studying algorithms for isotonic regression, simplifies the exposition of existing algorithms and leads to several new efficient algorithms. We also investigate the computational complexity of several algorithms.In this paper we consider the isotonic regression problem with respect to a complete order
where eachw
i
is strictly positive and eachy
i
is an arbitrary real number. We show that the Pool Adjacent Violators algorithm (due to Ayer et al., 1955; Miles, 1959; Kruskal, 1964), is a dual feasible active set method and that the Minimum Lower Set algorithm (due to Brunk et al., 1957) is a primal feasible active set method of computational complexity O(n
2). We present a new O(n) primal feasible active set algorithm. Finally we discuss Van Eeden's method and show that it is of worst-case exponential time complexity.This work was supported by the National Science and Engineering Research Council of Canada under Research Grant A8189 and an Ontario Graduate Scholarship. 相似文献
3.
Summary The exchange of Co(NH3)6]3+-ions on amberlite IRC-50 resin has been studied at room temperature. For this exchange process the cations are effective
in the order: Cs+<Rb+<K+<Na+<Li+<NH4
+<Mg2+ <Ca2+<H+ and (C2H5)4N<(CH3)4N+ ≪Cetyltrimethylammonium-ion <Cetylpyridinium-ion.
The logarithm of the selectivity coefficient gives linear graphs when plotted against the radius of the hydrated ions or the
reciprocals of theDebye-Hückel parameter?. 相似文献
4.
5.
An investigation is made of the influence of band non-parabolicity on the relation between the Fermi energies in the presence and absence of magnetic quantization in degenerate semi-conductors through derivation of a simplified form of the relation.On leave of absence from theDept. of Physics, B. N. College, Patna University, Patna 800004. 相似文献
6.
A. N. Chakravarti A. K. Chowdhury K. P. Ghatak D. R. Choudhury 《Czechoslovak Journal of Physics》1980,30(10):1161-1166
An expression is derived for the diffusivity-mobility ratio of the carriers in n-channel inversion layers on semiconductors like the ternary compounds which have strongly non-parabolic energy bands. The dependence of the ratio on alloy composition is also studied under the weak-field limit taking n-channel Hg1–xCdx.Te as an example.On leave of absence fromthe Department of Physics, Patna University, Patna, India. 相似文献
7.
Summary Cation exchange studies have been carried out between Mg-saturated bentonite and vermiculite and a number of monovalent electrolytes. According to the distribution and selectivity coefficients the cations are preferred in the order: Li Na43)4N (C2H5)4N for betonite and Li < Na < NH4 < K < Rb < Cs < H and (C2H5)4N < (CH3)4N for vermiculite. The selectivity coefficient of H+ is found to be much greater than other inorganic ions.TheG-values of the cation exchange reaction have been calculated by an equation ofBarrer. The experimental data were analyzed by the theoretical approach ofPauley too. 相似文献
8.
K. Chakravarti und G. J. Pontrelli 《Colloid and polymer science》1978,256(1):104
Ohne Zusammenfassung 相似文献
9.
Vij Mohit Garse Harshal Dand Neha Kadam Vilasrao Hirlekar Rajashree 《Journal of inclusion phenomena and macrocyclic chemistry》2010,67(1-2):39-47
The inclusion behaviour of β-cyclodextrin (βCD) was studied toward Cefdinir (CEF) in order to enhance the solubility and dissolution rate, following cyclodextrin complexation. Drug cyclodextrin solid systems were prepared by conventional methods of kneading (KN), co-evaporation (CE), spray drying (SD) and with a novel approach of microwave irradiation (MWI). The formation of inclusion complexes with βCD in the solid state, were confirmed by Differential scanning calorimetry (DSC), Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) studies, and comparative studies on the in vitro dissolution of CEF were carried out. Characterization of binary system by DSC, FTIR and SEM indicated that SD and MWI method resulted in formation of true complexes. Binary systems showed significant increase in dissolution rate as compared to plain drug. Amongst the binary systems MWI products were prepared in least time with better yield and highest dissolution rate. 相似文献
10.