Germanium—platinum

Some elements found in body tissues have no apparent physiological role, but have not been shown to be toxic. Examples are mbidium, strontium, titanium, niobium, germanium, and lanthanum. Other elements are toxic when found in greater than trace amounts, and sometimes in trace amounts. These latter elements include arsenic, mercury, lead, cadmium, silver, zirconium, beryUium, and thallium. Numerous other elements are used in medicine in nonnutrient roles. These include lithium, bismuth, antimony, bromine, platinum, and gold (Eig. 1). The interactions of mineral nutrients with... 

Fig. 9. Spectral sensitivity of detectors where the detector temperatures in K are in parentheses, and the dashed line represents the theoretical limit at 300 K for a 180° field of view, (a) Detectors from near uv to short wavelength infrared (b) lead salt family of detectors and platinum siUcide (c) detectors used for detection in the mid- and long wavelength infrared. The Hg CdTe, InSb, and PbSnTe operate intrinsically, the doped siUcon is photoconductive, and the GaAs/AlGaAs is a stmctured supedattice and (d) extrinsic germanium detectors showing the six most popular dopants.

Temperature The level of the temperature measurement (4 K, 20 K, 77 K, or higher) is the first issue to be considered. The second issue is the range needed (e.g., a few degrees around 90 K or 1 to 400 K). If the temperature level is that of air separation or liquefact-ing of natural gas (LNG), then the favorite choice is the platinum resistance thermometer (PRT). Platinum, as with all pure metals, has an electrical resistance that goes to zero as the absolute temperature decreases to zero. Accordingly, the lower useful limit of platinum is about 20 K, or liquid hydrogen temperatures. Below 20 K, semiconductor thermometers (germanium-, carbon-, or silicon-based) are preferred. Semiconductors have just the opposite resistance-temperature dependence of metals—their resistance increases as the temperature is lowered, as fewer valence electrons can be promoted into the conduction band at lower temperatures. Thus, semiconductors are usually chosen for temperatures from about 1 to 20 K. 

G6mez R, Llorca MJ, Feliu JM, Aldaz A. 1992. The behavior of germanium adatoms irreversibly adsorbed on platinum single crystals. J Electroanal Chem 340 349-355. 

One of the problems associated with the implementation of the standing wave technique is the fact that it requires the use of perfect or nearly perfect crystals. This presents a problem especially for relatively soft materials such as copper, gold, silver, and platinum, which are not only very difficult to grow in such high quality, but are also very difficult to maintain in that state. Thus, most experiments have been performed on silicon or germanium single crystals. 

Thus, several complexes with platinum-silicon or germanium bonds have been obtained ... 

A ligand-stabilized five-raembered cycle (355) containing two germanium atoms and one platinum atom <92ICA461> was obtained by depolymerization-eyclization of [Mc2GeCH2CH2GeMe2 Pt(PPli3)2] with diphos. 

Aluminium, 0048 Antimony, 4901 Barium, 0200 Beryllium, 0220 Bismuth, 0226 Cadmium, 3943 Caesium, 4248 Calcium, 3916 Cerium, 3955 Chromium, 4216 Cobalt, 4193 Copper, 4261 Europium, 4286 Gallium, 4400 Germanium, 4406 Gold, 0110 Hafnium, 4594 Indium, 3579 Iridium, 4638 Lanthanum, 4672 Lead, 4876 Lithium, 4675 Magnesium, 4685 Manganese, 4695 Mercury, 4595 Molybdenum, 4707 Neodymium, 4813 Nickel, 4814 Niobium, 4811 Osmium, 4867 Palladium, 4879 Platinum, 4881 Plutonium, 4882 Potassium, 4640 Praseodymium, 4880 Rhenium, 4884 Rhodium, 4886 Rubidium, 4883 Ruthenium, 4888... 

FT-ICR, see Fourier-transform ion cyclotron resonance Fullerene[60], germanium-germanium addition, 10, 748 Fullerenes with cobalt, 7, 51 on cobalt Cp rings, 7, 73 inside metallodendrimers, 12, 401 microwave applications, 1, 334 Pd rc-complexes, 8, 348 Ru—Os complexes, 6, 830 with tungsten carbonyls, 5, 687 )2-Fullerenes, with platinum, 8, 634 Fulvalene actinide complex, synthesis, 4, 232 Fulvalene chromium carbonyls, synthesis and characteristics, 5, 264... 

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