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The lanthanide contraction is the greater-than-expected decrease in atomic radii and ionic radii of the elements in the lanthanide series, from left to right. It is caused by the poor shielding effect of nuclear charge by the 4f electrons along with the expected periodic trend of increasing electronegativity and nuclear charge on moving from left to right.
Wound contracture is a process that may occur during wound healing when an excess of wound contraction, a normal healing process, leads to physical deformity characterized by skin constriction and functional limitations. [1] [2] [3] Wound contractures may be seen after serious burns and may occur on the palms, the soles, and the anterior thorax ...
The colors of the γ-sesquisulfides are La 2 S 3, white/yellow; Ce 2 S 3, dark red; Pr 2 S 3, green; Nd 2 S 3, light green; Gd 2 S 3, sand; Tb 2 S 3, light yellow and Dy 2 S 3, orange. [60] The shade of γ-Ce 2 S 3 can be varied by doping with Na or Ca with hues ranging from dark red to yellow, [ 49 ] [ 60 ] and Ce 2 S 3 based pigments are used ...
Lanthanide metals react exothermically with hydrogen to form LnH 2, dihydrides. [1] With the exception of Eu and Yb, which resemble the Ba and Ca hydrides (non-conducting, transparent salt-like compounds),they form black pyrophoric, conducting compounds [6] where the metal sub-lattice is face centred cubic and the H atoms occupy tetrahedral sites. [1]
Extrinsic ageing of skin is a distinctive declination process caused by external factors, which include ultra-violet radiation, cigarette smoking, air pollution, among others. Of all extrinsic causes, radiation from sunlight has the most widespread documentation of its negative effects on the skin.
[2] [3] Regardless of the driving force, the current density is found to be greatest at the conductor's surface, with a reduced magnitude deeper in the conductor. That decline in current density is known as the skin effect and the skin depth is a measure of the depth at which the current density falls to 1/e of its value near the surface. Over ...
[1] [2] However, due to the highly moisture and oxygen sensitive character of organolanthanide compounds, as well as the incapability of the separation of simple alkyl and aryl derivatives of the type LnR 3, this area of organometallic chemistry experienced a period of relative stagnation for two decades before lanthanocene complexes were ...
The long history of research into the active and passive electrical properties of the skin by a variety of disciplines has resulted in an excess of names, now standardized to electrodermal activity (EDA). [1] [2] [3] The traditional theory of EDA holds that skin resistance varies with the state of sweat glands in the skin.