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11.
Mazaahir Kidwai Preeti Misra Bhavesh Dave Kumar R. Bhushan Rajendra K. Saxena Meena Singh 《Monatshefte für Chemie / Chemical Monthly》2000,17(3):1207-1212
A novel synthesis of 6-fluoro-7-(5-aryl-1,3,4-thiadiazol/oxadiazol-2-yl-sulfanyl)-4-quinolone-3-carboxylic acids from 7-chloro-6-fluoro-4-quinolone-3-carboxylic acid and 5-substituted 1,3,4-thiadiazoles/oxadiazoles on basic alumina under microwave activation is described. All compounds were screened for their in vitro antibacterial activity against B. lichenformis, 2689, K. aerogens 2281, S. typhimurium 2501, E. herbicola 2491, and P. vulgaris 2027 and found to possess activities comparable to that of the standard drug norfloxacin. 相似文献
12.
Temperature dependent molar conductances and fluidities of bisulfate and ethyl sulfate anion-based ionic liquids were measured. The extent of dissociation of the ionic liquids was estimated from the Walden plot in term of ionicity. The ionicity mainly depends on the magnitude of Coulombic forces, altered by the anion’s Lewis basicity. Aqueous solutions of aprotic ionic liquids, in general, possesses ionicity in the range of ≈70–99%. This article reveals that the substitution of the anion by bisulfate and ethylsulfate reduces the ionicity of aqueous solution of these ionic liquids to the range of 10–37%. This is very close to that exhibited by some of the protic ionic liquids and phosphonium based ionic liquids with sweetner anions. The concentration dependent molar conductance of these ionic liquids has been fitted to Mahiuddin and Ismail’s equation. To our surprise, the molar conductances of bisulfate-based aprotic ionic liquids are remarkably high, even though these ionic liquids possess lower ionicity. 相似文献
13.
Jyotsna Galgale Nupinder Kaur Preeti Singh Manik Manake N. K. Gaur R. K. Singh 《Pramana》2004,63(2):413-417
An extended three-body force shell model (ETSM) has been applied to investigate the static and dynamic properties of KCN
x
Cl1−x
for the compositionx = 0.56 and 1.0 at 300 K. The phonon dispersion curves computed by us are compared with the single crystal neutron diffraction
data. The unusual features of these curves are the upward curvature seen in some of the acoustic branches. This is a result
ofK-dependent softening of the phonon due to translation-rotation coupling. The transverse acoustic branch is more soft near
the zone centre. 相似文献
14.
Avin Ramanjooloo Thierry Cresteil Cindy Lebrasse Girish Beedessee Preeti Oogarah Rob W.M. van Soest 《Natural product research》2015,29(4):383-387
This report describes the use of α-glucosidase to evaluate the anti-diabetic potential of extracts from marine sponges collected in the Mauritius waters. Initial screening at 1.0 mg/mL of 141 extracts obtained from 47 sponge species revealed 10 extracts with inhibitory activity greater than 85%. Seven of the 10 extracts were further tested at 0.1 and 0.01 mg/mL and only the methanol extract of two sponges namely Acanthostylotella sp. (ASSM) and Echinodictyum pykei (EPM) showed inhibition activity greater than 60% at 0.1 mg/mL with an IC50 value of 0.16 ± 0.02 and 0.04 ± 0.01 mg/mL, respectively, while being inactive at 0.01 mg/mL. 相似文献
15.
Structural and micro structural studies of PbO-doped SnO2 sensor for detection of methanol,propanol and acetone 下载免费PDF全文
In the present work the structural information of PbO-doped SnO2 thick film sensor has been investigated with X-ray diffractometer (XRD) and scanning electron microscope (SEM). Initially, SnO2 powder was derived using sol-gel process and was subsequently doped with PbO and ground up to nanosized particles. A suitable gas sensor structure was fabricated on 1′′×1′′ alumina substrate using thick film technology. The necessary paste for screen printing was also developed. SEM results showed sol-gel derived powder gets more agglomerated in the thick film form. The sensitivity of the sensor has been investigated at different temperatures (150 ?C?350 ?C) upon exposure to methanol, propanol and acetone, yielding a maximum at 250 ?C for acetone with 1 wt% PbO-doping while at 350 ?C for propanol with 3 wt% PbO-doping of the sensor. The reduction of particle size to nanometers (validated through XRD) leads to a dramatic improvement in sensitivity of sensors for the chosen organic vapors. The results also correlate well with the microstructural properties of the material and the dopant. 相似文献
16.
17.
A two-parametric nonstandard (Jordanian) deformation of the Lie algebra gl(2) is constructed and then, exploited to obtain a new, triangular R-matrix solution of the coloured Yang–Baxter equation. The corresponding coloured quantum group is presented explicitly. 相似文献
18.
Preeti S. Mishra Jignasa N. Solanki Z. V. P. Murthy 《Crystal Research and Technology》2013,48(11):969-976
In the present paper, suitable TiO2 nanoparticles are successfully synthesized by sol‐gel method, in order to utilize the freshly prepared TiO2 nanoparticles for proton exchange membrane (PEM) preparation. Titanium tetrachloride (TiCl4) is used as precursor and ethanol as a solvent. The optimum and suitable TiO2 nanoparticles were obtained by varying gelatinisation time (4–120 h), concentration of precursor (TiCl4) in ethanol (2–15 vol%), and reaction temperature (15–35 °C). The morphology, size and purity of the nanoparticles are investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and X‐ray diffraction (XRD). Optimum results were found at 4 h of gelatinisation time, 10% precursor concentration and 25 °C temperature for preparation of TiO2 nanoparticles. Thus prepared nanoparticles are found to be suitable for preparation of nanocomposite PEM, and consequently the prepared PEM indicates enhanced properties, such as, higher thermal stability (high glass transition temperature of 184.1 °C), excellent proton conductivity (0.0822 S cm−1 at room temperature) and low methanol permeability (1.11 × 10−9 cm2 s−1). 相似文献
19.
Preeti Mohindru 《代数通讯》2013,41(9):3818-3841
Drew, Johnson, and Loewy conjectured that for n ≥ 4, the CP-rank of every n × n completely positive real matrix is at most [n2/4]. While this conjecture has recently been disproved for completely positive real matrices, we show that this conjecture is true for n × n completely positive matrices over certain special types of inclines. In addition, we prove an incline version of Markham's theorems which gives sufficient conditions for completely positive matrices over special inclines to have triangular factorizations. 相似文献
20.
Retraction: Gairola, SP, Gairola, P, Shah, SK, Gupta, R. EMI shielding effectiveness of expanded graphite and reduced graphene oxide. J. Chin. Chem. Soc. 2018. https://doi.org/10.1002/jccs.201800189 . The above article, published online on 1 October 2018 in Wiley Online Library ( https://onlinelibrary.wiley.com ), has been retracted by agreement between the corresponding author, the journal's Editor‐in‐Chief, Dr. Yu‐Tai Tao, the Chemical Society Located in Taipei, and Wiley‐VCH Verlag GmbH & Co. KGaA. The retraction has been agreed due to several images across Figures 1, 2 and 3 within the article having been duplicated from other publications. The corresponding author apologizes for the inconvenience caused. 相似文献