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31.
Nasir N Yahya N Kashif M Daud H Akhtar MN Zaid HM Shafie A Teng LC 《Journal of nanoscience and nanotechnology》2011,11(3):2551-2554
This is our initial response towards preparation of nano-inductors garnet for high operating frequencies strontium iron garnet (Sr3Fe5O12) denoted as SrIG and yttrium iron garnet (Y3Fe5O12) denoted as YIG. The garnet nano crystals were prepared by novel sol-gel technique. The phase and crystal structure of the prepared samples were identified by using X-ray diffraction analysis. SEM images were done to reveal the surface morphology of the samples. Raman spectra was taken for yttrium iron garnet (Y3Fe5O12). The magnetic properties of the samples namely initial permeability (micro), relative loss factor (RLF) and quality factor (Q-Factor) were done by using LCR meter. From the XRD profile, both of the Y3Fe5O12 and Sr3Fe5O12 samples showed single phase garnet and crystallization had completely occurred at 900 degrees C for the SrIG and 950 degrees C for the YIG samples. The YIG sample showed extremely low RLF value (0.0082) and high density 4.623 g/cm3. Interesting however is the high Q factor (20-60) shown by the Sr3Fe5O12 sample from 20-100 MHz. This high performance magnetic property is attributed to the homogenous and cubical-like microstructure. The YIG particles were used as magnetic feeder for EM transmitter. It was observed that YIG magnetic feeder with the EM transmitter gave 39% higher magnetic field than without YIG magnetic feeder. 相似文献
32.
Darren Swanepoel Olinto DelFabbro WalterW. Focke Corrie Conradie 《Propellants, Explosives, Pyrotechnics》2010,35(2):105-113
Manganese metal was evaluated as a fuel for slow‐burning delay compositions press‐filled in aluminium or compaction‐rolled in lead tubes. Oxides of antimony, bismuth, copper, manganese and vanadium were considered as oxidants. Measured burn rates for binary mixtures varied between 5 and 22 mm s−1 but slower burning ternary and quaternary compositions were also found. The addition of fumed silica to the Mn/MnO2 system had little effect on the propagation rate but a low level addition of hollow glass sphere significantly reduced the burn rate. Mn MnO2 mixtures showed reliable burning over a wide stoichiometric range. In this system the fuel and the oxidant share a common metal. They combine to form the more stable intermediate oxide (MnO) releasing considerable quantities of heat in the process. 相似文献
33.
Jan W.H. Swanepoel 《Sequential Analysis》2013,32(4):333-344
An extension of a theorem by Woodroofe (1977) and Yu (1981) is provided which establishes, under certain conditions, the "asymptotic second-order efficiency" (in the sense of Ghosh and Mukhopadhyay (1981)) of certain stopping rules that arise from problems in sequential estimation. The outcome of a limited Monte Carlo study is also discussed. 相似文献