The interaction and its variation between magnetic grains in two kinds of magnetic recording tapes are investigated by first-order reversal curves （FORC） and the 5M method. The composition and microstructure of the ...The interaction and its variation between magnetic grains in two kinds of magnetic recording tapes are investigated by first-order reversal curves （FORC） and the 5M method. The composition and microstructure of the samples are characterised by x-ray diffraction and scanning electron microscope. The FORC diagram can provide more accurate information of the interaction and its variation, but the 5M curves cannot. The positive interaction field and the large variation of the interaction field have opposite effects on the δM curve.展开更多
As concerns the magnetic recording media made of acicular γ-Fe2O3 particles, the squareness S=M/M,, which depends on the angular distribution of easy magnetization axes of particles in the recording tapes, is a key p...As concerns the magnetic recording media made of acicular γ-Fe2O3 particles, the squareness S=M/M,, which depends on the angular distribution of easy magnetization axes of particles in the recording tapes, is a key parameter influencing its level of output symbols. There are a lot of investigations with magnetic measurement or M（?）ssbauer spectroscopy on the squareness and the angular distribution of magnetization axes in recording tapes.展开更多
An experiment concerning the sound propagation in aerated open channel flow was designed and conducted in a variable slope chute. The acquisition of sound data was done by the hydro-phones installed into the bottom wa...An experiment concerning the sound propagation in aerated open channel flow was designed and conducted in a variable slope chute. The acquisition of sound data was done by the hydro-phones installed into the bottom wall of the chute. The data were analyzed and processed by the tape recorder and a 3562A analyzer. The primary experimental results indicate that the sound speed in aerated flow is varied with the air concentration and highly lower than each of the sound speed in pure water or air. As released by the derived theoretical formula, the minimum sound of 24 m/s in aerated flow happened when the air concentration achieved to 50%. This result shows that the compressibility of high speed aerated flow should be considered when the air concentration is near to 50%. A criterion of compressibility of high speed aerated flow was also given in this paper.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50672008 and 50971023)Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20090006120019)
文摘The interaction and its variation between magnetic grains in two kinds of magnetic recording tapes are investigated by first-order reversal curves （FORC） and the 5M method. The composition and microstructure of the samples are characterised by x-ray diffraction and scanning electron microscope. The FORC diagram can provide more accurate information of the interaction and its variation, but the 5M curves cannot. The positive interaction field and the large variation of the interaction field have opposite effects on the δM curve.
文摘As concerns the magnetic recording media made of acicular γ-Fe2O3 particles, the squareness S=M/M,, which depends on the angular distribution of easy magnetization axes of particles in the recording tapes, is a key parameter influencing its level of output symbols. There are a lot of investigations with magnetic measurement or M（?）ssbauer spectroscopy on the squareness and the angular distribution of magnetization axes in recording tapes.
文摘An experiment concerning the sound propagation in aerated open channel flow was designed and conducted in a variable slope chute. The acquisition of sound data was done by the hydro-phones installed into the bottom wall of the chute. The data were analyzed and processed by the tape recorder and a 3562A analyzer. The primary experimental results indicate that the sound speed in aerated flow is varied with the air concentration and highly lower than each of the sound speed in pure water or air. As released by the derived theoretical formula, the minimum sound of 24 m/s in aerated flow happened when the air concentration achieved to 50%. This result shows that the compressibility of high speed aerated flow should be considered when the air concentration is near to 50%. A criterion of compressibility of high speed aerated flow was also given in this paper.
