Solid state lighting

Compared with single crystals, transparent ceramics offer several advantages, for example, lower cost, easy fabrication of materials of large size, and especially those with high melting points. Currently, transparent ceramics have found a wide range of application in lighting, solid state lasers, scintillators, windows and battle field etc. 

Technology developments are revolutionizing the spectroscopic capabilities at THz frequencies. While no one teclmique is ideal for all applications, both CW and pulsed spectrometers operating at or near the fiindamental limits imposed by quantum mechanics are now within reach. Compact, all-solid-state implementations will soon allow such spectrometers to move out of the laboratory and into a wealth of field and remote-sensing applications. From the study of the rotational motions of light molecules to the large-amplitude vibrations of... 

Selenium exhibits both photovoltaic action, where light is converted directly into electricity, and photoconductive action, where the electrical resistance decreases with increased illumination. These properties make selenium useful in the production of photocells and exposure meters for photographic use, as well as solar cells. Selenium is also able to convert a.c. electricity to d.c., and is extensively used in rectifiers. Below its melting point selenium is a p-type semiconductor and is finding many uses in electronic and solid-state applications. 

The reaction path shows how Xe and Clj react with electrons initially to form Xe cations. These react with Clj or Cl- to give electronically excited-state molecules XeCl, which emit light to return to ground-state XeCI. The latter are not stable and immediately dissociate to give xenon and chlorine. In such gas lasers, translational motion of the excited-state XeCl gives rise to some Doppler shifting in the laser light, so the emission line is not as sharp as it is in solid-state lasers. 

Nuclear reaction analysis (NRA) is used to determine the concentration and depth distribution of light elements in the near sur ce (the first few lm) of solids. Because this method relies on nuclear reactions, it is insensitive to solid state matrix effects. Hence, it is easily made quantitative without reference to standard samples. NRA is isotope specific, making it ideal for isotopic tracer experiments. This characteristic also makes NRA less vulnerable than some other methods to interference effects that may overwhelm signals from low abundance elements. In addition, measurements are rapid and nondestructive. 

Not a solid-state measurement device but an optical probe of high-intensity laser light is introduced into the fluid under investigation, avoiding disturbance on the flow field. 

Isoindoles are reactive toward oxidizing agents, and precautions usually advocated in the preparation of these compounds to prevent their oxidation merit careful consideration. The end products of oxidation are most often colored, resinous materials of indeterminate structure. The oxidative reactions appear to be accelerated by light and occur much more rapidly in solution than in the solid state. In a separate but possibly related process, certain isoindoles undergo polymerization in the solid state to give resins which, according to... 

Telluradiazolines are thermally stable crystal compounds, but they are very sensitive to light. When exposed to daylight, telluradiazolines undergo rapid decomposition, even in the solid state. By heating degassed solutions of telluradiazoline 79a in deuterochloroform or benzene, telluroketone 85 and alkenes 81 and 82 are formed in almost quantitative yield (93JA7019). 

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