This paper explores implications of previous work which suggested that pulp refining is achieved by a small number of impacts.As a consequence,the purpose of multiple bar crossings in refiners is to expose many fibres...This paper explores implications of previous work which suggested that pulp refining is achieved by a small number of impacts.As a consequence,the purpose of multiple bar crossings in refiners is to expose many fibres to a few effective cycles,not to impose many cycles on each fibre.Based on this postulate,tensile strength increase was found to be well described by a cumulative probability equation having two parameters:(a) number of bar crossings and(b) probability of a successful refining outcome at each crossing.In this paper,this concept further with additional refiner data was explored and the link between the probability term and measurable refiner variables was examined.By proposing the possibility,these two parameters may be a desirable alternative to specific energy and specific edge load for characterizing refining action.展开更多
The attenuation of seismic signals is often characterized in the frequency domain using statistical measures of the power spectrum. However, the conventional Fourier transform-based power spectrum estimation methods s...The attenuation of seismic signals is often characterized in the frequency domain using statistical measures of the power spectrum. However, the conventional Fourier transform-based power spectrum estimation methods suffer from time-frequency resolution problems. Wigner-Ville distribution, which is a member of Cohen class time-frequency distributions, possesses many appealing properties, such as time-frequency marginal distribution, time-frequency localization, etc. Therefore, Wigner-Ville distribution offers a new way for estimating the attenuation of seismic signals. This paper initially gives a brief introduction to Wigner-Ville distribution and the smoothed Wigner-Ville distribution that is effective in reducing the cross-term effect, and then presents a method for seismic attenuation estimation based on the instantaneous energy spectrum of the Wigner-Ville distribution. A real data example from central Tarim Basin in western China is presented to illustrate the effectiveness of the proposed method. The results show that the Wigner-Ville distribution-based seismic attenuation estimation method can effectively detect the difference between reef, shoal and lagoon facies by their attenuation properties, indicating that the estimated seismic attenuation can be used for reef and shoal carbonate reservoir characterization.展开更多
文摘This paper explores implications of previous work which suggested that pulp refining is achieved by a small number of impacts.As a consequence,the purpose of multiple bar crossings in refiners is to expose many fibres to a few effective cycles,not to impose many cycles on each fibre.Based on this postulate,tensile strength increase was found to be well described by a cumulative probability equation having two parameters:(a) number of bar crossings and(b) probability of a successful refining outcome at each crossing.In this paper,this concept further with additional refiner data was explored and the link between the probability term and measurable refiner variables was examined.By proposing the possibility,these two parameters may be a desirable alternative to specific energy and specific edge load for characterizing refining action.
文摘The attenuation of seismic signals is often characterized in the frequency domain using statistical measures of the power spectrum. However, the conventional Fourier transform-based power spectrum estimation methods suffer from time-frequency resolution problems. Wigner-Ville distribution, which is a member of Cohen class time-frequency distributions, possesses many appealing properties, such as time-frequency marginal distribution, time-frequency localization, etc. Therefore, Wigner-Ville distribution offers a new way for estimating the attenuation of seismic signals. This paper initially gives a brief introduction to Wigner-Ville distribution and the smoothed Wigner-Ville distribution that is effective in reducing the cross-term effect, and then presents a method for seismic attenuation estimation based on the instantaneous energy spectrum of the Wigner-Ville distribution. A real data example from central Tarim Basin in western China is presented to illustrate the effectiveness of the proposed method. The results show that the Wigner-Ville distribution-based seismic attenuation estimation method can effectively detect the difference between reef, shoal and lagoon facies by their attenuation properties, indicating that the estimated seismic attenuation can be used for reef and shoal carbonate reservoir characterization.
