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481.
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
482.
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
483.
484.
Chauhan S.S. Dahiya R.P. Seungjun Yi Lonngren K.E. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1997,25(6):1425-1430
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
485.
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
486.
B.C. Chauhan M. Picariello J. Pulido E. Torrente-Lujan 《The European Physical Journal C - Particles and Fields》2007,50(3):573-578
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
487.
Bhavik S. Makwana Mayur I. Morja Prakashsingh M. Chauhan Kishor H. Chikhalia 《Journal of heterocyclic chemistry》2024,61(3):466-473
A novel strategy for the synthesis of 6-methyl benzofuro[3,2-c] quinoline derivatives via copper-catalyzed dehydrogenative C O arylation has been presented. Optimization studies have been carried out by varying various catalysts, bases, solvents, and other physical parameters. Keeping use of this dehydrogenative cross-coupling C O arylation reaction, a variety of bioactive building blocks like fused benzofuro quinoline heterocycles were smoothly assembled in moderate to higher yields. 相似文献
488.
Arun K. Das Pramod Kumar Nanda Nilabja Roy Chowdhury Premanshu Dandapat Mohammed Gagaoua Pranav Chauhan Mirian Pateiro Jose M. Lorenzo 《Molecules (Basel, Switzerland)》2021,26(2)
In recent years, considerable importance is given to the use of agrifood wastes as they contain several groups of substances that are useful for development of functional foods. As muscle foods are prone to lipid and protein oxidation and perishable in nature, the industry is in constant search of synthetic free additives that help in retarding the oxidation process, leading to the development of healthier and shelf stable products. The by-products or residues of pomegranate fruit (seeds, pomace, and peel) are reported to contain bioactive compounds, including phenolic and polyphenolic compounds, dietary fibre, complex polysaccharides, minerals, vitamins, etc. Such compounds extracted from the by-products of pomegranate can be used as functional ingredients or food additives to harness the antioxidant, antimicrobial potential, or as substitutes for fat, and protein in various muscle food products. Besides, these natural additives are reported to improve the quality, safety, and extend the shelf life of different types of food products, including meat and fish. Although studies on application of pomegranate by-products on various foods are available, their effect on the physicochemical, oxidative changes, microbial, colour stabilizing, sensory acceptability, and shelf life of muscle foods are not comprehensively discussed previously. In this review, we vividly discuss these issues, and highlight the benefits of pomegranate by-products and their phenolic composition on human health. 相似文献
489.
Ramaswamy Murugavel Ramasamy Pothiraja Namrata Singh 《Journal of organometallic chemistry》2007,692(10):1920-1923
Diorganotin dichloride-phosphonic diamide complex, [Ph2SnCl2(tBuP(O)(NHiPr)2)2] (1), is prepared by the addition of two equivalents of tBuP(O)(NHiPr)2 to one equivalents of Ph2SnCl2 either in the presence or absence of triethylamine. Compound 1 is a rare example of an all-trans SnA2B2C2 complex that contains H-bonded six-membered rings which are made up of six different main group elements. 相似文献
490.
Siddharth Mehta K. Prashanth Chauhan S. Kanagaraj 《Journal of nanoparticle research》2011,13(7):2791-2798
Nanofluid is an innovative heat transfer fluid with superior potential for enhancing the heat transfer performance of conventional
fluids. Though many attempts have been made to investigate the abnormal high thermal conductivity of nanofluids, the existing
models cannot precisely predict the same. An attempt has been made to develop a model for predicting the thermal conductivity
of different types of nanofluids. The model presented here is derived based on the fact that thermal conductivity of nanofluids
depends on thermal conductivity of particle and fluid as well as micro-convective heat transfer due to Brownian motion of
nanoparticles. Novelty of the article lies in giving a unique equation which predicts thermal conductivity of nanofluids for
different concentrations and particle sizes which also correctly predicts the trends observed in experimental data over a
wide range of particle sizes, temperatures, and particle concentrations. 相似文献