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排序方式: 共有481条查询结果,搜索用时 15 毫秒
21.
J. Menghani S. K. Agrawal Vikram Agarwal Dhaval Bhatt 《Transactions of the Indian Institute of Metals》2012,65(1):107-109
Reduced weight of automobiles for the purpose of fuel economy has encouraged the use of light metals especially aluminium
alloys. A356 Al alloy containing 7% Si and 0.3% Mg is widely used in automobile and aircraft industries due to excellent castability,
good corrosion resistance and good pressure tightness. A356 is age hardenable alloy and there is appreciable improvement in
strength and hardness achievable due to precipitation of intermetallic compound Mg2Si. In the present investigation, aluminium alloy A356 with and without rare earth (RE) addition (0.5 wt%) was subjected to
single ageing as well as double aging treatment. The results were compared for mechanical properties like hardness and ultimate
tensile strength with the material not containing RE additions. 相似文献
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The authors describe the fabrication and evaluation of a novel leukodepletion filter using novel poly(ethylene-vinyl alcohol) membranes through electrospinning. The membranes were biocompatible and nonhemolytic. A prototype of the filter was developed by stacking the membranes in a poly(methyl methacrylate) case. Upon whole blood filtration, the filter could achieve 100% leukodepletion while capturing 8% red blood cells and 91% platelets. The length of filtration through the developed filter was high when compared to that of marketed filter while overall performance of the filter was comparable to that of the marketed filter. 相似文献
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Mohd. Hashim Sagar E. Shirsath S.S. Meena Pramod Bhatt R.K. Kotnala Shalendra Kumar Ravi Kumar Dachepalli Ravinder Alimuddin 《Ceramics International》2014
The Cr3+ ions doped multi-oxide ZnFe2−xCrxO4 ferrite nanoparticles have been synthesized by chemical co-precipitation method. Site occupancies of Zn2+, Cr3+ and Fe3+ ions were analyzed using X-ray diffraction data and Buerger's method. The effect of the constituent phase variation on the magnetic hysteresis behavior was examined by saturation magnetization which decreases with the increase in Cr3+ content in place of Fe3+ ions at octahedral B-site. Typical blocking temperature (TB) around 90 K was observed by zero field cooling and field cooling magnetization study. Room temperature Mössbauer spectra show two paramagnetic doublets (tetrahedral and octahedral sites). The isomer shifts of both doublets decrease whereas quadrupole splitting and relative area of tetrahedral A-site increases with increasing Cr3+ substitution. The dielectric constant (measured on compositions x=0, 0.4, 0.8 and 1.0) increases when the temperature increases as in the semiconductor. This behavior is attributed to the hopping of electrons between Fe2+ and Fe3+ ions with a thermal activation. 相似文献
27.
A selection of material using a novel type decision-making method: Preference selection index method
The aim of the current study is to implement a novel tool to help the decision-maker for selection of a proper material that will meet all the requirements of the design engineers. Preference selection index (PSI) method is a novel tool to select best alternative from given alternatives without deciding relative importance between attributes. In the present study, three different types of material selection problems are examined. A validation and consistency test of preference selection index method is performed in present work by comparing results of PSI method with published results of graph theory and matrix approach (GTMA), and technique for order preference by similarity to ideal solution (TOPSIS) method, respectively. The research has concluded that the PSI method is logical and more appropriate for the material selection problems. 相似文献
28.
Bhatt BC Dhabekar BS Sanaye SS Shinde SS Moharil SV Gundu Rao TK 《Radiation protection dosimetry》2002,100(1-4):251-253
L3PO4:Mg,Cu, a low effective atomic number and high sensitivity TSL phosphor, has been prepared. Its TSL glow curve shows a major peak around 360 degrees C with minor peaks around 110 degrees C and 230 degrees C. The optimum concentrations of the dopants are found to be 200 ppm each. Its gamma sensitivity is 1.2 times as compared to CaSO4:Dy (0.1 mol%). The optimum preirradiation annealing treatment is found to be 650 degrees C, 15 min. Its PL emission shows a band at 370 nm with excitation band at 250 nm. Dose to TSL response shows that its response is linear up to the gamma dose of 100 Gy for irradiations carried out at RT. An irradiated sample shows a distinct new ESR signal, which is tentatively assigned to an electron/hole localised on one of the oxygen(s) of the phosphate group. Step annealing experiments show decay of the defect centre around 340 degrees C. This correlates well with the TSL peak around 360 degrees C. 相似文献
29.
Jignasu P. Mehta Prashant N. Bhatt Sudhindra N. Misra 《中国稀土学报(英文版)》2006,24(6):648-652
Pr( Ⅲ ) and Nd( Ⅲ ) can be utilized as absorption spectroscopic probes to investigate the interaction of biomolecules like Lysozyme (HEW) with Ca( Ⅱ ) in-vitro ; the most abundant metal ion in the human body system. The spectroscopic techniques involving comparative absorption, absorption difference, and quantitative intensity analysis using 4f-4f transitions are utilized for changes in the inner sphere coordination pattern of Pr( Ⅲ ) and Nd(Ⅲ ) in solution as well as in solid state. The present study deals with an important biomolecule in human metabolism, that is, Lysozyme (HEW). The absorption er-Condon the probab spectral parameters such as the oscillator strength (P), the Judd-Ofelt (Tλ) intensity parameters, and the Slatinter electronic parameters are calculated using chi square methods. The obtained results are used to determine le geometry of the complex in the solution, the nature of the bond between Pr(Ⅲ)/Nd(Ⅲ) with lysozyme, and the inner sphere coordination environment of f-f transitions. The results obtained from various experimental conditions are utilized to investigate the coordination changes in the Pr(Ⅲ)/Nd(Ⅲ) complexes caused by different coordinating sites of lysozyme, normalized bite, denticity, the solvent nature, the coordination number, the nature of bond and other parameters to mimic the interaction of the Ca( Ⅱ ) ion with such biomolecule. 相似文献
30.
Rovee-Collier Carolyn; Bhatt Ramesh S.; Chazin Sharon 《Canadian Metallurgical Quarterly》1996,22(5):1178
The effects of set size and novelty on visual pop-out in 6-month-old infants was assessed in a perceptual-identification (memory reactivation) paradigm in which infants, trained and tested in their own homes, viewed a mobile containing a unique novel or familiar object amidst different numbers of familiar or novel distractors, respectively. Unique objects of both types popped out at all set sizes except the largest, where there was modest evidence that familiar distractors speeded processing (Experiment 1). When the proportion of familiar targets in a display of intermediate set size was increased, however, infants no longer detected the familiar target (Experiment 2). These findings offer additional support for the proposition that visual pop-out in infants and adults is the same phenomenon. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献