106 research outputs found
Temperature dependence of contact resistance of Au-Ti-Pd2Si-n+-Si ohmic contacts
We investigated temperature dependence of contact resistance of an
Au-Ti-Pd2Si ohmic contact to heavily doped n+-Si. The contact resistance
increases with temperature owing to conduction through the metal shunts. In
this case, the limiting process is diffusion input of electrons to the metal
shunts. The proposed mechanism of contact resistance formation seems to realize
also in the case of wide-gap semiconductors with high concentration of surface
states and dislocation density in the contact
On a feature of temperature dependence of contact resistivity for ohmic contacts to n-Si with an n+-n doping step
We present both theoretical and experimental temperature dependences of contact resistivity ρс(Т) for ohmic contacts to the silicon n+-n-structures whose n+-layer was formed using phosphorus diffusion or ion implantation
Functional Characterization of Lamina X Neurons in ex-Vivo Spinal Cord Preparation
Functional properties of lamina X neurons in the spinal cord remain unknown despite
the established role of this area for somatosensory integration, visceral nociception,
autonomic regulation and motoneuron output modulation. Investigations of neuronal
functioning in the lamina X have been hampered by technical challenges. Here we
introduce an ex-vivo spinal cord preparation with both dorsal and ventral roots still
attached for functional studies of the lamina X neurons and their connectivity using an
oblique LED illumination for resolved visualization of lamina X neurons in a thick tissue.
With the elaborated approach, we demonstrate electrophysiological characteristics
of lamina X neurons by their membrane properties, firing pattern discharge and
fiber innervation (either afferent or efferent). The tissue preparation has been also
probed using Ca2+ imaging with fluorescent Ca2+ dyes (membrane-impermeable or
-permeable) to demonstrate the depolarization-induced changes in intracellular calcium
concentration in lamina X neurons. Finally, we performed visualization of subpopulations
of lamina X neurons stained by retrograde labeling with aminostilbamidine dye to
identify sympathetic preganglionic and projection neurons in the lamina X. Thus, the
elaborated approach provides a reliable tool for investigation of functional properties
and connectivity in specific neuronal subpopulations, boosting research of lamina X of
the spinal cord
Morphogenetic basis of the unified state register of soil resources of Russia
Nomenclature and taxonomic diversity of soils and their horizon-profile diagnostics/descriptions define morphogenetic soil indicators used in the Unified State Register of Soil Resources of Russia (with Russian abbreviation of EGRPR). Most of these soil indicators are of non-metric origin, i.e., established conventionally by agreement. Subject area of soil science includes a hierarchy of 5 types of soil objects (pit, profile, horizon, morphological element and sample), 380 indicators, 607 methods and 3019 values of the indicators
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