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1.
S. C. Joshi M. P. Singh V. P. Pandey B. S. Rajput 《International Journal of Theoretical Physics》2002,41(6):1107-1125
In four-dimensional N = 4 supersymmetric gauge theory, we obtain an exact metric on the moduli space of quantum vacua and analyze the spectra of BPS states in weak as well as in strong coupling regions. Identifying the hypermultiplet of the dyonic state as a string stretched between D3-brane probe and a 7-brane, we demonstrate that the two hypermultiplets, which become massless at two singularities in supersymmetric theory, correspond to open strings beginning on the D3-brane and ending on the respective 7-brane. 相似文献
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3.
M. U. Rajput Mahmud Ahmad Waqar Ahmad 《Journal of Radioanalytical and Nuclear Chemistry》2002,251(3):457-462
The characteristic absolute efficiency response curves of a high purity germanium detector (HPGe) for different counting geometries have been established in the energy range 50–1500 keV by measuring the absolute efficiencies using both mono-energetic and multi-gamma emitting radionuclide point calibrated sources supplied by IAEA. Several fitting functions proposed in the literature were assessed for interpolation within the intermediate energy range of interest. The values of the function parameters have been determined by using the linear least square methods. The problems associated with the measurements of experimental efficiency data at small source–detector distances and the importance of the correlation matrix in the estimation of precise uncertainties have been shown. It was found that the inclusion of correlation matrices in the propagation of error formulae plays a significant role up to 450 keV gamma-ray energy and results in a drastic reduction of errors associated with the predicted efficiencies. The discrepancy at closer counting geometries in the absence of true gamma-gamma coincidence corrections is found to reach to about 30%. 相似文献
4.
Considering quarks as dyons, we analyze different possibilities for free fractional electric charges and monopoles to coexist. For nonvanishing vacuum angle, electric charges of dyons are not exactly fractional, but carry extra charges proportional to. The average extra charge vanishes for mesons, but not for baryons. 相似文献
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S. K. Tyagi A. K. Pandey S. Sahu V. Bajala J. P. S. Rajput 《Journal of Thermal Analysis and Calorimetry》2013,111(3):1791-1799
This article presents the experimental study and comparative performance evaluation of four types of cook stoves using energy and exergy analysis. Analysis of four different types of cook stove models viz. Envirofit, Mangla, Harsha and Vikram were selected and the water boiling test has been carried out. The suitable biomass available from the local market was prepared in the proper size as described in the Bureau of Indian Standards (BIS) and has been used as the fuel for cook stove in this experimental study. The aluminium pots of proper capacity as per BIS standard have been used for different cook stoves. The data from the experiments was collected and evaluated for the energy and exergy efficiencies for different models. Based on the data analysis it is found that the exergy efficiency is much lower than that of the energy efficiency for all the four models. It is also found that the both the efficiencies of Envirofit model are found to be higher than those of other models studied here. 相似文献
7.
Metal-free synthesis of substituted imidazole [1,2-a]pyridines from deprotective N-(prop-2-yn-1-yl)pyridin-2-amines in water is elucidated. Electron releasing substituents on pyridine ring provided pure products in quantitative yields without separation by column chromatography. 相似文献
8.
Somnath Dasgupta‡ Vishal Kumar Rajput‡ Bimalendu Roy 《Journal of carbohydrate chemistry》2013,32(2):91-106
Lanthanum trifluoromethanesulfonate‐catalyzed solvent‐free per‐O‐acetylation with stoichiometric acetic anhydride proceeds in high yield (95%–99%) to afford exclusively pyranose products as anomeric mixtures. Subsequent anomeric substitution employing borontrifluoride etherate and thiols or alcohols furnished the corresponding 1,2‐trans‐linked thioglycosides and O‐glycosides, respectively, in good to excellent overall yield (75%–85%). Alternatively, reaction of free sugars in neat alcohol employing the same catalyst at elevated temperature gives the corresponding 1,2‐cis‐linked O‐glycosides (along with 1,2‐trans‐linked glycosides as minor product) in good yield (73%–80%). Anomeric mixtures of compounds thus produced were characterized as their per‐O‐acetylated derivatives. 相似文献
9.
Some new 4-(2,6-diarylpyridin-4-yl)-2H-chromen-2-one derivatives 5a–l have been synthesized by reacting 4-(3-oxo-3-arylprop-1-enyl)-2H-chromen-2-ones 3a–c with appropriate 1-(2-oxo-2-arylethyl)pyridinium bromide salt 4a–d in the presence of ammonium acetate in refluxing glacial acetic acid. The newly synthesized compounds have been characterized by elemental and spectral analysis. 相似文献
10.
Schiff base N,N′-bis(salicylidene)-p-phenylenediamine (LH2) complexed with Pt(en)Cl2 and Pd(en)Cl2 provided [Pt(en)L]2 · 4PF6 (1) and Pd(Salen) (2) (Salen = N,N′-bis(salicylidene)-ethylenediamine), respectively, which were characterized by their elemental analysis, spectroscopic data and X-ray data. A solid complex obtained by the reaction of hexafluorobenzene (hfb) with the representative complex 1 has been isolated and characterized as 3 (1 · hfb) using UV–Vis, NMR (1H, 13C and 19F) data. A solid complex of hfb with a reported Zn-cyclophane 4 has also been prepared and characterized 5 (4 · hfb) for comparison with complex 3. The association of hfb with 1 and 4 has also been monitored using UV–Vis and luminescence data. 相似文献