喷油井
发表于 2025-4-1 04:28:06
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Manifest
发表于 2025-4-1 08:38:07
M. M. Chawla,R. Subramanianst radio astronomical measurements are made at frequencies well above this limit. At the low-frequency limit ionospheric effects can be important; these are of great intrinsic interest for geophysics, but usually are of little consequence with regard to radio astronomy.
能够支付
发表于 2025-4-1 10:38:23
T. N. T. Goodmanitizers. In Chap. 5, Prac- cal Receiver Systems. we have relegated the presentations of maser and parametric ampli?er front ends, which are no longer commonly used as microwave receivers in radio astronomy, to a short section on “historical developments” and We have retained and improved the present
fidelity
发表于 2025-4-1 16:30:55
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