31 research outputs found

    Ground state EIT cooling of 171^{171}Yb+^+ ion

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    The work propose a scheme of deep laser cooling of 171^{171}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 171^{171}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

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    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

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    Androgen deficiency and lower urinary tract symptoms in patients with benign prostatic hyperplasia

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    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
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