d layer การใช้

• At night, when the D layer dissipates, mediumwave transmissions travel better by skywave.
• Basically, the printer deposits a uniformly thick 2-D layer on a substrate.
• During daylight hours, the lower D layer of the ionosphere forms and absorbs lower frequency energy.
• The upper mesosphere is also the region of the ionosphere known as the " D layer ".
• You'd layer wave after wave after wave, trying to get one little spike in the center.
• At night, especially in winter months and at times of low solar activity, the lower ionospheric D layer virtually disappears.
• At night, especially in winter months and at times of low solar activity, the ionospheric D layer can virtually disappear.
• The ground wave and the first hop ( or sky ) wave reflected at the ionospheric D layer interfere with each other.
• At night the F layer is the only layer of significant ionization present, while the ionization in the E and D layers is extremely low.
• The D layer is only present during the day, when some ionization occurs with nitric oxide being ionized by Lyman series-alpha hydrogen radiation.
• However at certain times the D layer ( at a lower altitude than the refractive E and F layers ) can be electronically noisy and absorptive of MF waves, interfering with skywave propagation.
• Because of high D layer absorption, 80 meters is less reliable for over intercontinental distances, but is the most popular band for regional communications networks through the late afternoon and night time hours.
• These waves are reflected and attenuated on the ground as well as within the ionospheric D layer, near 70 km altitude during day time conditions, and near 90 km height during the night.
• At distances that are typically towards the edge of the ground wave coverage area, some sky-wave signal may also be present, especially at night when the D layer attenuation is reduced.
• Fabrication methods for three-dimensional ones include drilling under different angles, stacking multiple 2-D layers on top of each other, direct laser writing, or, for example, instigating self-assembly of spheres in a matrix and dissolving the spheres.
• The TWIM consists of vertically fitted ?-Chapman-type layers, with distinct F2, F1, E, and D layers, for which the layer parameters such as peak density, peak density height, and scale height are represented by surface spherical harmonics.
• As the sun sets, the D layer weakens, allowing medium wave radio waves from such stations to bounce off the F layer of the ionosphere, producing reliable, long distance reception of ( especially ) high-powered stations up to about 1, 200 miles ( 2, 000 km ) away on a nightly basis.