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本文主要介绍噪声控制工程和设备的评价技术、噪声控制技术的规范化、噪声控制技术的计算机辅助工具、声学材料和噪声设备等领域的国内外发展现状,并对我国上述领域今后的发展提出了一些建议。 相似文献
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Self-induced stochastic resonance in excitable systems 总被引:4,自引:0,他引:4
Cyrill B. Muratov Eric Vanden-Eijnden Weinan E. 《Physica D: Nonlinear Phenomena》2005,210(3-4):227-240
The effect of small-amplitude noise on excitable systems with strong time-scale separation is analyzed. It is found that vanishingly small random perturbations of the fast excitatory variable may result in the onset of a deterministic limit cycle behavior, absent without noise. The mechanism, termed self-induced stochastic resonance, combines a stochastic resonance-type phenomenon with an intrinsic mechanism of reset, and no periodic drive of the system is required. Self-induced stochastic resonance is different from other types of noise-induced coherent behaviors in that it arises away from bifurcation thresholds, in a parameter regime where the zero-noise (deterministic) dynamics does not display a limit cycle nor even its precursor. The period of the limit cycle created by the noise has a non-trivial dependence on the noise amplitude and the time-scale ratio between fast excitatory variables and slow recovery variables. It is argued that self-induced stochastic resonance may offer one possible scenario of how noise can robustly control the function of biological systems. 相似文献
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本文简述环境声学的发展过程以及在厅堂音质、环境噪声和噪声控制方面的新世纪展望。 相似文献
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Mechanisms of active control of sound transmission through a linked double-wall system into an acoustic cavity 总被引:2,自引:0,他引:2
The mechanism of active control on sound transmission through a mechanically linked double-wall structure into an acoustic cavity is investigated in this paper. Two control methods, i.e., structural control and acoustic control under two linkage cases (soft and hard) are investigated to analyze the effect of the links on the selection of control strategies and the corresponding control mechanisms. Simulations are performed to examine the dominant control mechanism (modal suppression or modal rearrangement) in different frequency ranges for each control case. The alteration in the structural-acoustic coupling is also analyzed so as to explain the mechanisms of sound attenuation. In addition, the dominance of the acoustic mode (0, 0, 0) in the energy transmission process as well as its use in designing a more effective sensor/actuator arrangement is discussed. 相似文献
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The performances of barriers having different shapes and surface conditions were tested using the boundary element method in a well-controlled environment. The heights and widths of the barriers were standardized and the insertion losses for six receiver positions were averaged and compared. Figures displaying the results allow for straightforward barrier performance estimation. It was shown that absorbing and soft edges significantly improve the efficiency of the barrier, but configuration modifications provide only a slight improvement. The soft T-shaped barrier produces the highest performance. A 3 m high T-shaped barrier provides the same performance as a 10 m high plain barrier. The spectral efficiency was also investigated. The insertion loss spectra for the absorbing and the soft barriers exhibit a similar shape, but the rigid barrier differs from these two. 相似文献
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