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31.
Mithu VS Paul S Kurur ND Madhu PK 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2011,209(2):359-363
We compare in this communication several heteronuclear dipolar decoupling sequences in solid-state nuclear magnetic resonance experiments under a magic-angle spinning frequency of 60 kHz. The decoupling radiofrequency field amplitudes considered are 190 and 10 kHz. No substantial difference was found among the sequences considered here in performance barring the difference in the optimisation protocol of the various schemes, an aspect that favours the use of swept-frequency two pulse phase modulation (SW(f)-TPPM). 相似文献
32.
Bandi Madhu B. Raja sekar C. H. Venkata Ramana Reddy P. K. Dubey 《Research on Chemical Intermediates》2017,43(12):6993-7012
The intermediate-dependent green and efficient synthesis of dimeric quinolones 4a–l and 7a–l by the Knoevenagel condensation followed by Michael-type addition of 4-hydroxy-1-methylquinolin-2(1H)-one 1a, b to indole-3-aldehydes 2a–f and aromatic aldehydes 5a–l in water through the condensed compound 3a–l under catalyst-free conditions is described. This reaction was found to be environmentally friendly, has easy-workup and shorter reaction times giving good yields of the product without the need for its isolation using column chromatography. 相似文献
33.
介绍了一种新型等离子体刻蚀机的使用条件,通过对各种参数变化的组合实验,得到了最佳工艺数据.利用该刻蚀机生产的电池片刻蚀效果好,刻蚀后经检测,电池片漏电流小,并联电阻大,提高了电池片的综合性能指标. 相似文献
34.
A general Ni-catalyzed process for the cross-coupling of secondary alkylzinc halides and aryl/heteroaryl iodides has been developed. This is the first process to overcome the isomerization and β-hydride elimination problems that are associated with the use of secondary nucleophiles, and that have limited the analogous Pd-catalyzed systems. The impact of salt additives was also investigated. It was found that the presence of LiBF(4) dramatically improves both isomeric retention and yield for challenging substrates. 相似文献
35.
Livanov K Madhu V Balaraman E Shimon LJ Diskin-Posner Y Neumann R 《Inorganic chemistry》2011,50(22):11273-11275
The catalytic photocleavage of CS(2) to S(8) and a (C(x)S(y))(n) polymer with visible light using a dinuclear ruthenium(II) compound with a bipyridine units for photoactivity and a vicinal tertiary amine binding site for CS(2) activation was studied. The catalyst was characterized by X-ray diffraction, (1)H NMR, and (13)C NMR, ESI-MS and elemental analysis. CS(2) photocleavage was significant (240 turnovers, 20 h) to yield isolable S(8) and a (C(x)S(y))(n) polymer. A mononuclear catalyst or one without an amine binding site showed significantly less activity. XPS of the (C(x)S(y))(n) polymer showed a carbon/sulfur ratio ~1.5-1.6 indicating that in part both C-S bonds of CS(2) had been cleaved. Catalyst was also included within the polymer. The absence of peaks in the (1)H NMR verified the (C(x)S(y))(n) nature of the polymer, while (13)C NMR and IR indicated that the polymer had multiple types of C-S and C-C bonds. 相似文献
36.
Madhu Bhaskaran Sharath Sriram Simon Ruffell Arnan Mitchell 《Advanced functional materials》2011,21(12):2251-2257
We report on the use of nanoindentation to characterize in situ the voltage and current generation of piezoelectric thin films. This work presents the controlled observation of nanoscale piezoelectric voltage and current generation, allowing accurate quantification and mapping of force function variations. We characterize both continuous thin films and lithographically patterned nanoislands with constrained interaction area. The influence of size on energy generation parameters is reported, demonstrating that nanoislands can exhibit more effective current generation than continuous films. This quantitative finding suggests that further research into the impact of nanoscale patterning of piezoelectric thin films may yield an improved materials platform for integrated microscale energy scavenging systems. 相似文献
37.
Sudhana JM Munikishore R Reddy MV Gunasekar D Blond A Bodo B 《Natural product communications》2011,6(11):1569-1572
A new acylated labdane diterpenoid, 14-deoxy-3,19-diacetyl-11,12-didehydroandrographolide (1), together with three known labdane diterpenoids, wightionolide (2), andrographolide (3) and neoandrographolide (4), and three known flavones, echioidinin (5), skullcapflavone I 2'-methyl ether (6) and echioidin (7), were isolated from the whole plant of Andrographis wightiana. The structure of compound 1 was elucidated by 1D and extensive 2D-NMR spectral studies. 相似文献
38.
39.
The liquid phase benzylation of o-xylene with benzyl chloride over rare earth oxide catalysts like CeO2 and Pr2O3 was studied in a batch reactor at atmospheric pressure and 363 K. Surface area, pore volume, DTA, acid strength distribution on the catalyst surface and optimum temperature of the catalyst are reported. 相似文献
40.
Electronically connecting medical experts with patients permits remote care delivery from diagnostics to surgery. Traditional visual computing tasks such as volume rendering or image processing may also become more available when electronically local. Recent innovations in media processing and client-server technology will help process both video and graphics in real time and enable an electronically local environment for healthcare 相似文献