排序方式: 共有64条查询结果,搜索用时 15 毫秒
51.
Rao IN Boruah A Kumar SK Kunwar AC Devi AS Vyas K Ravikumar K Iqbal J 《The Journal of organic chemistry》2004,69(6):2181-2184
An acyclic tripeptide based on a heterochiral D-pro-L-pro template shows a propensity to exist as a 3(10) helical conformation and can be cyclized, via ring-closing metathesis, to the corresponding cyclic tetrapeptides without disrupting the helical conformations in CDCl(3) as well as in DMSO-d(6) solutions. The detailed conformational studies were carried out by using NMR spectroscopy, X-ray crystallography, molecular dynamic simulations, and circular dichroism spectroscopy. 相似文献
52.
Synthesis and Antifungal Activities of Some New 5,7‐Disubstituted[1,2,4]Triazolo[1,5‐a]Pyrimidin‐6‐one Derivatives
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Susanta Kumar Borthakur Sukanya Borthakur Debarshi Goswami Paran Boruah Pabitra Kumar Kalita 《Journal of heterocyclic chemistry》2016,53(6):2079-2083
Synthesis of a new series of [1,2,4]triazolo[1,5‐a]pyrimidin‐6‐one by [4 + 2]cycloaddition reaction of 3‐benzylidineamino[1,2,4]triazole with monophenyl ketene and diphenyl ketene generated in situ from phenylacetyl chloride and diphenylacetyl chloride in the presence of triethylamine is described. The newly synthesized compounds were also tested for antifungal activities against Rhizoctonia solani and Trichoderma sp. 相似文献
53.
We delineate an experimental observation of the effect of the magnetic field along with mesh grid biasing in the presence of a cylindrical plasma bubble in a filamentary discharge magnetised plasma system. The cylindrical mesh grid of 80% optical transparency has been negatively biased and introduced in the plasma for creating a plasma bubble. Plasma floating potential fluctuations have been taken outside (LP1) and inside (LP2) of the plasma bubble. It has been noticed that as the external magnetic field is increased the oscillation pattern shows intermittent route to chaos as the system evolved from regular type of relaxation oscillations (of larger amplitude) to an irregular type of oscillations (of smaller amplitude) We have used recurrence quantification analysis (RQA) to the observed intermittency to chaos in the plasma. The main measures of RQA are laminarity (LAM) and determinism (DET). The laminarity measure can be associated with the average time between the chaotic burst in the intermittency. It has also been observed that the DET depends on the control parameter and decreases exponentially, features like a dip in skewness and a hump in the kurtosis with the variation of control parameter have been noticed, which are the strong evidence of intermittent behaviour of the system. Further, a numerical model has been developed to the observed experimental analysis of the intermittent route to chaos. 相似文献
54.
We find new partition identities arising from Ramanujan’s formulas of multipliers. Several of the identities are for overpartitions, overpartition pairs, and \(\ell \)-regular partitions. 相似文献
55.
Pallabi Saikia Partha Pratim KaishapRashmi Prakash Kommuri ShekarraoSanjib Gogoi Romesh C. Boruah 《Tetrahedron letters》2014
The preparation of steroid/nonsteroid fused 7-substituted pyrazolo[1,5-a]pyrimidines is described by a one-pot reaction of steroidal/nonsteroidal ketones, aromatic aldehydes and 3-amino-1H-pyrazoles/5-amino-1H-pyrazoles in the presence of potassium tert-butoxide in good yield under reflux condition in ethanol. 相似文献
56.
Partha Pratim Kaishap Swagata BaruahKommuri Shekarrao Sanjib Gogoi Romesh C. Boruah 《Tetrahedron letters》2014
The steroidal and nonsteroidal 5-methyl pyrazolo[1,5-a]pyrimidines were synthesized by the reaction of steroidal/nonsteroidal α,β-unsaturated ketones and 3-amino-1H-pyrazoles/5-amino-1H-pyrazoles in the presence of KOtBu in ethanol under reflux condition. 相似文献
57.
Properties of steady state ion sheath formed in front of a negatively biased metal plate under the influence of negative ions
have been investigated in collisionless argon/SF6 plasma. This experiment is carried out at a fixed discharge voltage and fixed filament heating power. In this experiment,
the decrement in plasma pre-sheath potential drop as well as positive ion drift velocity toward the plate is experimentally
recorded in the presence of negative ions. It is also found that the plasma positive ion density and plasma electron temperature
decrease in the presence of negative ions. These factors attribute to the decrease of ion current toward the plate. Hence
the usual ion sheath expands.
Article presented at the International Conference on the Frontiers of Plasma Physics and Technology, 9–14 December 2002, Bangalore,
India. 相似文献
58.
Kushal C. Lekhok Dipak Prajapati Ramesh C. Boruah Sharbani Mazumder Tarun C. Borah 《Monatshefte für Chemie / Chemical Monthly》2009,18(4):1183-1187
Abstract
3-Aryl-2,1-benzisoxazoles and its salts underwent reductive cleavage of the N–O bond leading to 2-aminobenzophenones with bakers’ yeast under non-fermenting conditions in aqueous media. The procedure gives excellent yields of 2-alkylamino- and 2-aminobenzophenones. 相似文献59.
Unpredictable noise and transfer function in power line channel make it a hostile environment for communication. The paper
presents an algorithm which is implemented on a TMS320C6713 Digital Signal Processor (DSP) to select the best channel suitable
for transmission. A design of a suitable hardware where the system can be used is also presented. 相似文献
60.
Cerium chloride heptahydrate proves to be an efficient catalyst for Michael addition of 1,3-dicarbonyl compounds, through a simple solvent free reaction under microwave irradiations. 相似文献