排序方式: 共有44条查询结果,搜索用时 15 毫秒
1.
Saikat SAMANTA Siddhartha MUKHERJEE Rajib DEY 《中国有色金属学会会刊》2014,24(9):2976-2985
钛磁铁矿是一种复杂的共生矿石,含有钛铁矿、磁铁矿、铁铝尖晶石和镁铁铝尖晶石等矿物。对从印度东部采集到的钛磁铁矿石进行XRD、WDXRF、SEM和M?ssbauer谱分析。在氧气气氛下,通过TG-DTA分析对矿石的氧化行为进行研究。随后,在氧气和空气气氛下,将样品在不同温度下(873-1473 K)保温不同时间,进行等温氧化实验。观察到在较低的温度下钛铁矿相转变为赤铁矿、氧化钛,而在较高的温度下转变为钛酸亚铁相。将氧化后的矿样与焦炭混合压制成圆柱形球团,在1473 K下进行直接还原,成功地实现了将磁铁矿铁转变为氧化铁和二氧化钛的相变。 相似文献
2.
ASHIT KUMAR MUKHERJEE DINES CHANDRA SAHA GANTI PRASADA RAO 《International journal of systems science》2013,44(7):777-788
This paper is concerned with two practically important aspects of identification of large scale distributed parameter systems by the multidimensional Poisson moment functional (MDPMF) method (Saha and Prasada Rao 1980). The existing methods of (i) development and diagrammatic representations of the relations among the MDPMFs of partial derivative terms and those of the original multivariable function, and (ii) elimination of the effects of boundary functions and their partial derivatives from the identification equations, become extremely unwieldy as the order and dimensions of the model increase. This paper suggests alternative techniques in these two situations, leading to a simplification of the algorithm and an enormous reduction of the related analytical and computational burden. In the former situation, the suggested alternative uses the concept of separated variables. In the latter, the boundary function effects are estimated and then inserted into the algorithm to simplify it. 相似文献
3.
4.
The graphs of the sets of all penultimate implicants of certain types of Boolean functions are obtained in this part of the paper. Identification of different C.H. Boolean functions with their graphs are then made and terms are coined to designate these functions for the easy pattern recognition of their graphs. Finally formulae are deduced which give the number of prime implicants that must be present in any minimal cover of these functions. 相似文献
5.
U SYAMAPRASAD A. R SHEEJA NAIR M. S SARMA P GURUSWAMY P. S MUKHERJEE A. D DAMODARAN L KRISHNAMURTHY M ACHUTHAN 《Journal of Materials Science: Materials in Electronics》1997,8(3):199-205
Coexistence of pyrochlore phase is one of the major problems in the preparation of lead magnesium niobate (PMN) based perovskites
as it leads to deterioration of the dielectric and piezoelectric properties. Although the columbite precursor method substantially
reduces the formation of pyrochlore phase, the success of this process depends on various process conditions such as reactivity
of MgO, level of mixing or grinding, control of PbO volatility and reversibility of the reaction. Compositions in the system
(1−x)[(1−y)PMN yPT]x BT (where PT = PbTiO3 and BT = BaTiO3) were prepared by the columbite route. Results show that addition of excess MgO and 4PbO·B2O3 glass before sintering not only eliminates the pyrochlore phase completely but also produces a series of ceramics with low
firing temperature, very high dielectric constant, low dissipation factor, high d.c. resistivity and extremely low temperature
coefficient of capacitance (TCC). The unusually low TCC values make these high K dielectrics suitable for application in multilayer
ceramic capacitors having EIA specifications Y5P, Y5R and Y5S.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
7.
Abstracts are not published in this journal 相似文献
8.
S. MUKHERJEE 《The International journal of environmental studies》2013,70(2):249-258
Arsenate uptake by aquatic plant water lettuce (Pistia stratiotes L.) was studied in the laboratory condition to investigate a low cost natural aquatic treatment system for pollutant removal. The plants were harvested from a local pollution‐free pond in young condition and hydroponically cultured in the laboratory. Bio‐accumulation was noticed to be both concentration and duration dependent. The results show that the plant could effectively absorb arsenic between a range of 0.25 to 5.0 mg/l to the extent of 82.0 to 22.8% for a biomass of 20 g/l at pH 7.0 after 144 h. The results were also plotted in Langmuir and Freundlich isotherms and the data were well fitted. The sorption capacity was evaluated as 1.43 mg/g for the Langmuir isotherm and 1.01 mg/g for the Freundlich isotherm. The removal efficiency was, however, noted to be maximum (87.5%) at pH 6.5. The effect of biomass quantity has also been investigated along with some metabolic parameters. 相似文献
9.
A CHATTERJEE P MUKHERJEE N GAYATHRI P BARAT ARNAB BARAT A SARKAR 《Bulletin of Materials Science》2011,34(5):1113-1117
The Portevin–Le Chatelier (PLC) effect is a kind of plastic instability observed in many dilute alloys when deformed at certain
ranges of strain rate and temperature. In this paper we present a comprehensive statistical analysis of the observed experimental
data obtained during PLC effect and establish that the occurrence probability of the stress drops in the dynamical process
responsible for PLC effect is Poisson in nature. 相似文献
10.