相关论文: UVB-Radiation-Induced Apoptosis in Jurkat Cells: A…
Pulses of extreme ultraviolet (XUV) light, with wavelengths between 10 and 100$\,$nm, can be used to image and excite ultra-fast phenomena such as the motion of atomic electrons. Here we show that the illumination of plasma with…
We use Interface Region Imaging Spectrograph (IRIS) spacecraft data to study a group of Chromospheric ultraviolet bursts (UVBs) associated with an active region. We classify the UVBs into two types: smaller ones that can only be measured…
Optimally doped cuprate superconductors are characterized by the presence of superconducting fluctuations in a relatively large temperature region above the critical transition temperature. We reveal here that the effect of thermal…
We obtained ultraviolet and optical spectra for 9 M~dwarfs across a range of rotation periods to determine whether they showed stochastic intrinsic variability distinguishable from flares. The ultraviolet spectra were observed during the…
Ultra-Violet Imaging Telescope (UVIT) is one of the five payloads aboard the Indian Space Research Organization (ISRO)'s ASTROSAT space mission. The science objectives of UVIT are broad, extending from individual hot stars, star-forming…
The Alice ultraviolet spectrograph on board the \textit{Rosetta} orbiter provided the first near-nucleus ultraviolet observations of a cometary coma from arrival at comet 67P/Churyumov-Gerasimenko in 2014 August through 2016 September. The…
Daily monitoring of PKS 2155-304 with the IUE satellite throughout November 1991 has revealed dramatic, large-amplitude, rapid variations in the ultraviolet flux of this BL Lac object. Many smaller, rapid flares are superimposed on a…
The shape of the UV ionizing background is reconstructed from optically thin metal absorption-line systems identified in spectra of HE2347-4342, Q1157+3143, and HS1700+6416 in the redshift interval 1.8 < z < 2.9. The systems are analyzed by…
We explore the effects of UV absorbing material on the shape of the EUV continuum radiation emitted by the active galactic nucleus, and on the relative strengths of emission lines, formed in the narrow line regions of Seyfert galaxies,…
Results of the initial calibration of the Ultra-Violet Imaging Telescope (UVIT) were reported earlier by Tandon et al. (2017). The results reported earlier were based on the ground calibration as well as the first observations in orbit.…
We present ultraviolet (UV) spectroscopic observations covering three distinct accretion states of the low-mass X-ray binary (LMXB) MAXI J1820+070: the luminous hard state, a hard-intermediate state and the soft state. Our observations were…
The effects of the X-rays carried out in a photon beam produced by a medical linear particle accelerator on the progression of the cell cycle in normal cells Vero were evaluated by flow cytometric mean. The evaluation of the consequences of…
We discuss the diagnostic potential of high cadence ultraviolet spectral data when transient ionization is considered. For this we use high cadence UV spectra taken during the impulsive phase of a solar flares (observed with instruments…
We present UV imaging polarimetry data of the Seyfert 2 galaxy Mrk 3 taken by the Hubble Space Telescope. The polarized flux is found to be extended to ~1 kpc from the nucleus, and the position angles of polarization are centrosymmetric,…
Irradiation of a medium by short intense pulses from x-ray / XUV free electron lasers can result in saturated photoionization of inner electronic shells. As a result an inversion of populations between core levels appears. The resulting…
It is shown, that spontaneous ultraviolet radiation of cells (infusoria) plays the role of agent, restricting the upper limit of the quantity of cells in quasi-stationary phase of cultire's development. The spectral region of this radiation…
The environmental impact of metal complexes such as organotin(IV) compounds is of increasing concern. Genotoxic effects of organotin(IV) compounds (0.01 microg/ml, 0.1 microg/ml or 1.0 microg/ml) were measured using the alkaline single-cell…
A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 meter off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast…
We stabilize an ultraviolet diode laser system at 369.5 nm to the optical absorption signal from Yb+ ions in a hollow-cathode discharge lamp. The error signal for stabilization is obtained by Zeeman spectroscopy of the 3 GHz-wide absorption…
A novel characterization method to measure the pulse duration of ultrafast near-IR pulses is introduced, which uses simple tabletop optics, is relatively inexpensive, and is expected to work in a broad wavelength range. Our diagnostic tool…