نتایج جستجو برای: ultraviolet spectrometer
تعداد نتایج: 61544 فیلتر نتایج به سال:
Introduction: Ultraviolet (UV) radiation affects human organs such as skin, eyes and immune system, as well as animals and plants. The main natural source of UV radiation is the Sun. To study the effects of solar UV radiation there is a need to quantify variations of solar energy received on the earth surface at different intervals. Materials and Methods: To measure UV radiation a broadband fib...
Abstract Transit spectroscopy is a key tool for exoplanet atmospheric characterization. However, transit spectrum observations can be limited by aerosol extinction when gas opacities are weak. The ultraviolet wavelength range contains variety of strong molecular and atomic features, potentially enabling species detection even hazes present. To understand the interplay between opacities, we inve...
The ultraviolet photochemistry of vinylacetylene (C4H4) was studied under temperature and pressure conditions similar to Titan's atmosphere by exciting the molecule in a constrained expansion that opens into the ion source region of a time-of-flight mass spectrometer. The primary dissociation products detected by vacuum-ultraviolet ionization were found to be C4H3 and C4H2, in a ratio of 3-10 :...
We describe a state-of-the-art tunable ultraviolet (UV) Raman spectrometer for the 193-270 nm spectral region. This instrument allows for steady-state and transient UV Raman measurements. We utilize a 5 kHz Ti-sapphire continuously tunable laser (approximately 20 ns pulse width) between 193 nm and 240 nm for steady-state measurements. For transient Raman measurements we utilize one Coherent Inf...
Ozone is observed to be present in the polar regions of Mars and to have a seasonal variation. In the summer, the amount present in the polar atmosphere is less than 3 micrometer-atmospheres. In the fall, ozone increases in amount and is found in association with the formation of the polar hood. In winter, the maximum amount of ozone is present, 57 micrometer-atmospheres over the polar hood and...
Future prospects for solar spectroscopy missions operating in the extreme ultraviolet (EUV) and soft X-ray (SXR) wavelength ranges, 1.2–1,600 Å, are discussed. NASA is major funder of Solar Physics missions, brief summaries opportunities mission development under given. Upcoming from other nations also described. The methods observing Sun two ranges summarized with a discussion spectrometer typ...
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