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1.
The relationship between final hammer velocity and maximum amplitude of radiated piano sound was investigated. Piano tones with varying hammer velocities were produced by a computer-monitored acoustic piano containing optical sensors and solenoids, and the sounded tones were recorded and digitized for analysis. Maximum amplitudes over the duration of the sounded tones were linearly proportional to piano hammer velocities for a range of frequencies and hammer velocities. Changes in room acoustics did not alter the linear relationship. Measurements of maximum amplitudes of individual tones and combined tones (dyads) also indicated a linear relationship between the sum of the maximum amplitudes of the individual tones and the maximum amplitude of the dyads. These findings indicate that the principle of superposition holds for peak amplitudes of sounded piano tones. Findings are discussed with regard to production and perception of musical dynamics. 相似文献
2.
An all-fibre interferometer which allows the measurement of the movement (speed and distance) of a vibrating body is presented. An electronic signal processing scheme is used and this is contrasted with the measurement of velocity through an optical processing technique, which is however, more complex and expensive to implement. The overall simplicity of the electronic technique, the low cost of components and the use of an all-fibre arrangement make this an attractive system to implement where the more limited information available is sufficient for monitoring purposes. 相似文献
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John Palmer 《Communications in Mathematical Physics》1986,104(3):353-385
The large scale asymptotics of the correlations for a family of two dimensional lattice field theories is calculated at the critical temperature. 相似文献
10.
The first molal hydrolysis quotient, Q1.1, of Mg2+ was measured potentiometrically from 1 to 250°C at ionic strengths of 0.11, 0.31, 1.01, and 5.0 mol-kg-1 in an aqueous NaCl medium using a hydrogen-electrode, concentration cell. Only hydrolysis of the first four percent of the
magnesium in solution could be followed before precipitation of brucite, Mg(OH)2(cr), occurred. The log Q1.1 values were fitted as a function of temperature and ionic strength using four adjustable parameters. The resulting constants
are compared with the limited existing low temperature data. At infinite dilution and 25°C the following quantities are reported:
logK
1.1 = -11.68±0.05, †Hso = 70.1±1.2 kJ-mol-1, †So = 11±4 J-K-1-mol-1, and †C
p
o
= 0 J-K-1-mor-1. At each ionic strength, including the values extrapolated to infinite dilution, the heat capacity change for the hydrolysis
reaction was zero,i.e., logQ
1.1 was found to be a linear function of the reciprocal temperature in Kelvin, at least over the measured range of l-250°C. The
hydrolysis constants at infinite dilution were modeled to 550°C and two kbar pressure with a function incorporating solvent
density using published results obtained at these extreme conditions. 相似文献