31 research outputs found
Ground state EIT cooling of Yb ion
The work propose a scheme of deep laser cooling of Yb. The
cooling is based on the effect of electromagnetically induced transparency
(EIT) in a polychromatic field with three frequency components are resonant to
optical transitions of the ^2S_{1/2} \to \, ^2P_{1/2} line. The deep cooling
down to the ground motional state in a trap allows for a significant
suppression of the second order Doppler shift in frequency standards. Moreover,
there is no need to use a magnetic field, which is required for Doppler cooling
of Yb in a field with two-frequency component. The cooling
without use of magnetic field is important for deep suppression of quadratic
Zeeman shifts of clock transitions from uncontrolled residual magnetic fields
Extended defects in natural diamonds: Atomic Force Microscopy investigation
Surfaces of natural diamonds etched in high-pressure experiments in H2O, CO2
and H2O-NaCl fluids were investigated using Atomic Force Microscopy. Partial
dissolution of the crystals produced several types of surface features
including the well-known trigons and hillocks and revealed several new types of
defects. Besides well-known trigons and dissolution hillocks several new types
of defects are observed. The most remarkable ones are assigned to anelastic
twins of several types. The observation of abundant microtwins, ordering of
hillocks and presence of defects presumably related to knots of branched
dislocations suggests importance of post-growth deformation events on formation
of diamond microstructure. This work confirms previous reports of ordering of
extended defects in some deformed diamonds. In addition, the current work shows
that natural diamonds deform not only by dislocation mechanism and slip, but
also but mechanical twinning. The dominant mechanism should depend on
pressure-temperature-stress conditions during diamond transport from the
formation domain to the Earth surface.Comment: Submitted to special issue (1st European Mineralogical congress,
Frankfurt, Germany, September 2012) of European Journal of Mineralogy. 21
page, 9 figure
Androgen deficiency and lower urinary tract symptoms in patients with benign prostatic hyperplasia
This article analyzes the existing literature on late onset hypogonadism deficiency and its relationship with lower urinary tract symptoms and benign prostatic hyperplasia. Aspects of modern therapy and its effectiveness were considered. The possibility testosterone drugs use for men with late onset hypogonadism and lower urinary tract symptoms was analyzed. Evaluated the safety and efficacy of hormone replacement therapy.</em
Measurement of the frequency of acetylene transitions at 1540 nm with a mode-locked Cr:YAG laser
NRC publication: Ye