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排序方式: 共有196条查询结果,搜索用时 78 毫秒
101.
Vikas Dubey Jagjeet Kaur N. S. Suryanarayana K. V. R. Murthy 《Research on Chemical Intermediates》2014,40(2):531-536
This paper reports TL glow curve analysis and evaluation of kinetic parameter for Amarnath stone collected from Amarnath Holy Cave. TL was recorded with different heating rates (3.3, 4, 6.7, 8, and 10 ° s?1). The samples gave good TL peaks at 310, 314, 308, 323, and 327 °C for the different heating rates. The corresponding activation energy (E) values were calculated. The peaks were indicative of second-order kinetics. Samples were characterized by XRD analysis. Inductively coupled plasma activated emission spectroscopic (ICP–AES) analysis was performed to determine percentages of elements in the natural mineral. Results from ICP–AES and XRF (X-ray fluorescence spectroscopy) studies were compared. 相似文献
102.
Jagjeet Kaur Deepti Singh Vikas Dubey N. S. Suryanarayana Yogita Parganiha Pooja Jha 《Research on Chemical Intermediates》2014,40(8):2737-2771
In this review different methods of preparing lanthanum aluminate (LaAlO3) phosphors are discussed. The molten salt method, the combustion method, the sucrose method, and the coprecipitation technique are the best methods for preparing LaAlO3 phosphors with small particle size and high surface area by low-temperature synthesis. LaAlO3 usually has a rhombohedral structure. It has good dielectric properties and, hence, is regarded as an attractive alternative to SiO2 in microelectronic devices. LaAlO3 phosphors have excellent chemical and thermal stability, mechanical durability, and exploitable optical and electronic properties, leading to a wide range of potential applications. LaAlO3 phosphors doped with rare-earth ions have luminescence properties and can, hence, be used in optical display systems. 相似文献
103.
A rapid, efficient, economical, and easy-to-scale method for the effective conversion of carbamates to corresponding N,N-dichlorocarbamates by using sodium hypochlorite in acidic medium has been described. N,N-Dichlorocarbamates were obtained in quantitative yield through a simple workup in reduced reaction time.
104.
Vikas Dubey Jagjeet Kaur N. S. Suryanarayana K. V. R. Murthy 《Research on Chemical Intermediates》2013,39(8):3689-3697
This paper reports the thermoluminescence (TL) and chemical characterization of natural calcite collected from Kodwa mines of the C.G. Basin. The sample was irradiated with a 10-Gy dose from an Sr-90 beta source. The heating rate used for TL measurements was 6.7 °/s. The sample had a good TL peak at approximately 127 °C and the corresponding kinetic parameter were calculated. The effect of annealing temperature is also described for natural calcite. The photoluminescence excitation spectrum at ~254 nm and the corresponding emission spectrum peak at 395 nm are reported. Inductively coupled plasma–activated emission spectroscopy (ICP–AES) was conducted to determine the percentages of elements in the calcite mineral. 相似文献
105.
B. Gopala Krishna Ravichandra Gundakaram S. V. Suryanarayana R. D. K. Misra 《Physica C: Superconductivity and its Applications》1992,200(3-4):425-433
Samples with the nominal composition Bi2Sr2Ca1−xNaxCu2Oy (if with X = 0.05, 0.2, 0.4 and 0.5) were prepared by the solid state reaction method. The role of Na and the effect of various heat treatments in the 2212 composition were studied. From the X-ray diffraction data it is found that the samples annealed for longer duration have shown a single phase 2212. From the DC four-probe resistivity data, it was found that the Tc (zero) varies from 79 to 89 K. It is believed that doping with an alkali element would reduce the oxygen content due to monovalency and gives an effect similar to that during heat treatment under low oxygen pressure or quenching. The presence of sodium in the samples was confirmed by electron probe microanalysis. 相似文献
106.
H. Naik V.T. Nimje D. Raj S.V. Suryanarayana A. Goswami Sarbjit Singh S.N. Acharya K.C. Mittal S. Ganesan P. Chandrachoodan V.K. Manchanda V. Venugopal S. Banarjee 《Nuclear Physics A》2011
The yields of various fission products in the 10 MeV bremsstrahlung-induced fission of 232Th, 238U and 240Pu were determined using a recoil catcher and off-line γ-ray spectrometric techniques. From the yield data, mass yield distributions were obtained using charge distribution corrections. The higher yields of fission products around mass numbers 133–135, 138–140, 143–145 and their complementary products in the neutron and bremsstrahlung-induced fission of 232Th, 238U and 240Pu were interpreted based on nuclear structure effects. From the mass yield distribution, the peak-to-valley (P/V) ratio was also obtained for the above fissioning systems. The present data, along with data from the literature on different bremsstrahlung- and mono-energetic neutron-induced fissions of 232Th and 238U are interpreted to examine the influence of excitation energy on the peak to valley ratio. For the same compound nucleus 240Pu?, the data in the 10–30 MeV bremsstrahlung-induced fission of 240Pu were compared with similar data of thermal to 14 MeV neutron-induced fission of 239Pu and the spontaneous fission of 240Pu to examine the role of excitation energy due to bremsstrahlung radiation and mono-energetic neutrons. 相似文献
107.
Interfacial waves on condensate films inside ducts increase heat transfer rates and lead to changes inflow regimes. We report the results of an experimental study of interfacial waves with condensation of a vapor on the cooled bottom surface of horizontal duct and with air-glycerine-water mixture flow in an identical duct. R-I13 and FC-72 (developed by the 3M Company) were used in the condensation experiments. Wavy flow patterns with two- and three-dimensional waves were observed. Interfacial waves with condensation appeared when the vapor velocity was in the range 1.24-1.56 m/sfor R-I13 and 0.81-1.13 m/sfor FC-72, corresponding to vapor Reynolds numbers in the range 20,000-30,000—the value depends on the difference in the temperatures of the condensing surface and saturated vapor. The ratio of the distance from the leading edge (at which the waves appeared) to the liquid film thickness was found to be a Junction of the liquid Reynolds number. Condensation stabilizes the interface. None of the several available criteria for the incipience of the waves was found to be satisfactory. A modification to the criterion employed by Jensen and Yuen ill is suggested. Other details such as wave speed and wave separation distance are included. 相似文献
108.
109.
Prasad Mutyala Veera Venkata Vara Rao Radha Hunasenahalli Raghavendra Veeranna Vadde Chennupalli Venkata Suryanarayana Sathish Byrappa 《Russian Journal of General Chemistry》2021,91(12):2522-2526
Russian Journal of General Chemistry - Novel quinolone derivatives have been designed and readily synthesized according to a simple protocol including O-alkylation and Claisen rearrangement... 相似文献
110.