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541.
In this work, we experimentally study the effect of externally applied magnetic field on a ladder type EIT in a vapour cell consisting of 87Rb atoms. The introduction of magnetic field causes the Zeeman splitting of the hyperfine levels of 87Rb atoms and hence the number of available windows of transparency increases. We report the observation of nine such windows. Such multi window EIT systems are capable of storing pulses at the different frequencies, corresponding to these windows hence paving the way for realization of multi frequency quantum memories. Also, the total bandwidth of storage is 218.4 MHz which is two orders of magnitude higher than that typically obtained in single window EIT based storage systems. These systems have tremendous applications in the field of speedy transmission of data over a long distance quantum communication channel.  相似文献   
542.
This is the first-time ammonium thiocyanate (NH4SCN) has been used as a self-promoting reactant for the synthesis of 3,4-dihydropyrimidin-2(1H)-thiones. This report describes a greener, efficient and economic protocol for one pot three-component synthesis of Biginelli compounds using various aldehydes, β-ketoesters and ammonium thiocyanate. Ammonium thiocyanate being a weak acid, accelerate the rate of reaction to obtain Biginelli compounds in solvent-free condition at 110 °C. The key advantages of the present method are high yields, short reaction time, solvent free condition, easy workup and ability to tolerate a variety of functional groups. Ammonium thiocyanate is readily available, cheaper, safer and industrial acceptable material which gives economical as well as ecological rewards to the present method.  相似文献   
543.
In this paper, the dispersion characteristics of a plasma filled elliptical Bragg waveguide is investigated. The modal characteristic equations of the proposed Bragg waveguide for both ω > ωp and ω < ωp are derived. The effects of plasma frequency, numbers of cladding layers and the eccentricity of elliptical Bragg waveguide on the dispersion characteristics are studied. The analysis shows that the introduction of plasma in the proposed waveguide allows to control the propagation of modes.  相似文献   
544.
The biomimetic oxidation of curcumin, a main turmeric pigment with hydrogen peroxide catalyzed by different 5,10,15,20-tetraarylporphyrinatoiron(III) chlorides [TAPFe(III)Cl] in dichloromethane has been studied to give a C-C coupled curcumin dimer in 40-70% yield. The structure of the dimer has been elucidated by (1)H-, (13)C-NMR, IR and FAB-Mass spectroscopic data.  相似文献   
545.
XANES and EXAFS techniques are proving very popular in the study of local environment in disordered systems. Results of such studies in a large number of metal (Fe, Co, Ni, etc)-metalloid (B, Si, C, etc) glasses are reported. Experiments were done with synchrotron radiation as well as an x-ray tube. The values of bond lengths and co-ordination numbers computed from one-electron single scattering Fourier transform method turn out substantially smaller. The values of bondlength determined from the other EXAFS calculation method and the multiple-scattering computation scheme show good agreement. Importance of choice of suitable reference materials for analysis of data is emphasized. The experimental work was done at EXAFS 5.1 Station at Daresbury Laboratory, U.K.  相似文献   
546.
547.
The variable coefficient modified Korteweg-de Vries (mKdV) equations for incident and reflected solitons are derived and solved to study the reflection of compressive and rarefactive ion acoustic solitons at the critical density in an inhomogeneous negative ion plasma. The polarity of the incident compressive and rarefactive solitons is not altered during the reflection process. Increasing the density gradient reinforces the reflection of both compressive and rarefactive mKdV solitons, whereas enhancement of the unperturbed plasma density weakens the reflection  相似文献   
548.
The biomimetic oxidation of etodolac, an anti-inflammatory drug (1) with iodosylbenzene catalyzed by 5,10,15,20-tetraarylporphyrinatoiron(III) chlorides TAPFe(III)Cl (7a-e) in dichloromethane gives 4-hydroxyetodolac (6) and 4-oxoetodolac (5) regioselectively in moderate yields.  相似文献   
549.
The complementarity between the quark and lepton mixing matrices is shown to provide a robust prediction for the neutrino mixing angle θ13 PMNS. We obtain this prediction by first showing that the matrix VM, product of the CKM and PMNS mixing matrices, may have a zero (1,3) entry, which is favored by the experimental data. Hence models with bimaximal or tribimaximal forms of the correlation matrix VM are quite possible. Any theoretical model with a vanishing (1,3) entry of VM, which is in agreement with the quark data, and the solar and the atmospheric mixing angle leads to θ13 PMNS=(9+1 -2)°. This value is consistent with the present 90% CL experimental upper limit. PACS 14.60.Pq; 14.60.Lm; 96.40.Tv  相似文献   
550.
In the current scenario, people are highly concerned regarding their health and constantly desire a healthy and nutritious diet. Moringa oleifera is traditionally known as saijhan or drumstick tree. The plant is native to tropical Asia and thus found in various parts of the country India. Being a nutrient-rich plant, Moringa leaves play a vital role in the treatment of malnutrition. It also has anti-inflammatory, anti-spasmodic, anti-asthmatic, anti-ulcer, hypocholesterolemic, and hypoglycemic properties. Fresh fruits have also been desirable and in growing demand, because of healthy food consumption trends worldwide. The following study was undertaken to provide nutrient-rich food in the busy growing lifestyle. Thus, in this study, preparation and optimization of the Moringa leaf powder have been done. The final product is developed by incorporating Moringa leaf powder into pomegranate juice to prepare a ready-to-serve (RTS) beverage. On the basis of this study, it concluded that 100:2:2.8:0.2 concentration of Pomegranate, Moringa oleifera leaf powder, Sugar, Citric Acid is suitable for the preparation of Ready to Serve Beverage. In this study, proximate analysis and sensory evaluation have been performed to understand the overall acceptability of the final product.  相似文献   
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