CHIDE
发表于 2025-3-23 09:49:00
The EU in Global Energy GovernanceFigure 7 presents atmospheric attenuation data and inverse square losses at several distances for relative humidities of 20 and 80%. In this form, the data are useful for recording engineers in estimating sound pickup characteristics at large microphone distances.
Indebted
发表于 2025-3-23 15:15:16
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是贪求
发表于 2025-3-23 19:17:20
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landmark
发表于 2025-3-24 00:47:29
Electrochemical Energy Storage SystemsFigure 11 gives the nominal length of an open pipe that will resonate at a particular frequency. This occurs when the pipe is approximately equal in length to one-half the wavelength of the frequency. Pipes that are particularly large in diameter may need to be modified in length, in order to determine their actual “speaking length.”
Limerick
发表于 2025-3-24 05:49:11
Y. F. Xu,Ming Li,Y. F. Wang,Ruzhu WangAssume that the open pipe in the previous example was specified as being of a particular diameter. We now want to determine what degree of end correction must be incorporated to attain the desired frequency. Figure 12 shows the relation between the increase in the speaking length of pipe and its length-to-radius ratio (L/R).
涂掉
发表于 2025-3-24 08:59:46
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LAITY
发表于 2025-3-24 11:44:00
Living reference work 20200th editionThe data given in Figure 15 show the measured on-axis response of a small loudspeaker placed, as shown, on several objects of the general dimensions indicated. It should be clear that shapes that avoid sharp transitions give a smooth response.
COMMA
发表于 2025-3-24 16:16:41
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FAST
发表于 2025-3-24 20:48:34
The Evolution of Complex Engineering SystemsRoom constant (R) identifies the effective absorption in a space in terms of square meters of totally absorptive surface. Its definition was given in section 17.
疲劳
发表于 2025-3-25 00:35:30
Sound Pressure and dB Lp (Sound Pressure Level)In virtually all acoustical level measurements, a reference pressure of 20 µN/m. (20 micropascals) is used to determine dB L.. The relevant equation is:. where .. An equivalent quantity in the CGS system of units is.0002 dynes/cm..