45 research outputs found
Modeling the spectrum of V4334 Sgr (Sakurai's Object)
Theoretical spectral energy distributions were computed for a grid of
hydrogen-deficient and carbon-rich model atmospheres of T(eff) in the range of
5000-6250 K and log g = 1.0 - 0.0 by the technique of opacity sampling, taking
into account continuous, molecular band and atomic line absorption. These
energy distributions were compared with the spectrum of V4334 Sgr (Sakurai's
object) of April, 1997 in the wavelength interval 300-1000 nm. We show that (1)
the shape of the theoretical spectra depends strongly on T(eff) but only very
weakly on the hydrogen abundance; (2) the comparison of the observed and
computed spectra permits to estimate T(eff) approximately 5500 K for V4334 Sgr
in April, 1997, and its interstellar reddening (plus a possible circumstellar
contribution) E(B-V) approximately 0.70.Comment: 7 pages, 8 figures, LaTeX, accepted by Astronomy and Astrophysic
Infrared and optical spectroscopy of alpha and gamma-phase Ce
We determined the optical properties of alpha- and gamma-phase Ce in the
photon energy range from 60 meV to 2.5 eV using ellipsometry and grazing
incidence reflectometry. We observe significant changes of the optical
conductivity, the dynamical scattering rate, and the effective mass between
alpha- and gamma-cerium. The alpha-phase is characterized by Fermi-liquid
frequency dependent scattering rate, and an effective mass of about 20 m_e on
an energy scale of about 0.2 eV. In gamma-Ce the charge carriers have a large
scattering rate in the far infrared, and a carrier mass characteristic of 5d
band electrons. In addition we observe a prominent absorption feature in
alpha-Ce, which is absent in gamma-Ce, indicating significant differences of
the electronic structure between the two phases.Comment: 5 pages, REVTeX, 2 eps-figures, Phys.Rev.Lett., in pres
Reading tea leaves worldwide: Decoupled drivers of initial litter decomposition mass‐loss rate and stabilization
The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models
Reading tea leaves worldwide: decoupled drivers of initial litter decomposition mass‐loss rate and stabilization
The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large‐scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass‐loss rates and stabilization factors of plant‐derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy‐to‐degrade components accumulate during early‐stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass‐loss rates and stabilization, notably in colder locations. Using TBI improved mass‐loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early‐stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models
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Reading tea leaves worldwide: decoupled drivers of initial litter decomposition mass-loss rate and stabilisation
The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models
Passive Q-switching and mode-locking for the generation of nanosecond to femtosecond pulses
A New Approach to the Estimation of Accuracy of Calculations of Vibrational Wavefunctions and Radiative Parameters
А new drug in the complex therapy of diabetes mellitus. Post-registration experience in patients with type 1 and type 2 diabetes mellitus
Diabetes mellitus (DM), due to its high incidence and prevalence, presents an urgent problem for the scientific community, which requires new ways of treating and preventing complications. Existing hypoglycemic treatment approaches do not always contribute to the achievement of glycaemic targets.Objective. Study of Subetta-based therapy for patients with DM 1 and DM 2 in real-life clinical practice.Materials and methods. The program involved 71 patients with DM 1 and 289 patients with DM 2, HbA1c ≥ 7.0%, who took Subetta in combination therapy of diabetes. The duration of the program was 12 weeks. The laboratory examination included the determination of the level of HbA1c, fasting plasma glucose.Results. The administration of Subetta in complex therapy of DM 1 and DM 2 led to a significant reduction in HbA1c from 9.2 ± 1.85 to 8.13 ± 1.29 mmol/L and from 8.62 ± 1.54 to 7.49 ± 1.1 mmol/L, respectively (p<0.0001), reduction of fasting blood glucose from 9.33 to 7.65 mmol/l and from 9.25 to 7.08 mmol/l, respectively (p<0.0001). The effectiveness of therapy is highly appreciated by patients and physicians. The use of Subetta was not accompanied by the development of hypoglycemia and other adverse effects.Conclusion. In real-life clinical practice, use of new locally developed antidiabetic drug Subetta demonstrated a significant decrease of HbA1c and fasting blood glucose, with no episodes of hypoglycemia in patients with DM 1 and DM 2