Microwave pulse, formation

The basic principle involved in electron spin echo spectroscopy is the formation of an echo. The simplest spin echo experiment uses two microwave pulses to form an echo, which is also... 

Sb can be shaped into NW by a number of approaches, e.g., pulsed electrode-position, patterning of nanoparticles, microwave-induced formation, and by using focused ion beams (FIB). For developing nanowires of Sb for pH measurements, the FIB technology was used. The material was exposed to a Ga" ion beam under high vacuum at room temperature. This procedure led to the formation of tangled Sb rods which formed a porous network of NW. 

Other microwave-assisted parallel processes, for example those involving solid-phase organic synthesis, are discussed in Section 7.1. In the majority of the cases described so far, domestic multimode microwave ovens were used as heating devices, without utilizing specialized reactor equipment. Since reactions in household multimode ovens are notoriously difficult to reproduce due to the lack of temperature and pressure control, pulsed irradiation, uneven electromagnetic field distribution, and the unpredictable formation of hotspots (Section 3.2), in most contemporary published methods dedicated commercially available multimode reactor systems for parallel processing are used. These multivessel rotor systems are described in detail in Section 3.4. 

The actual process is a combination of the gas-phase and heterogeneous reactions mentioned earlier, with the additional formation of water. The typical product composition observed in the experiments with pulsed microwave discharge in methanol is (molar fractions in gas phase) 55% hydrogen, 12% carbon monoxide (CO), 10% methane, 20% water, 1% carbon dioxide, 1% ethane, and 1% etlylene. The solid-to-gas ratio (C(s) C(g)) is close to 1 in this case, in good agreement with formula (10-17). 

In pulsed EPR spectroscopy, the magnetization is detected through formation and readout of an electron spin echo. In contrast to cw EPR, which uses relatively weak microwave powers (slOO mW), pulsed EPR... 

Thermal rearrangement of the simple allyl ether was successful in preliminary studies (Eq. 3.1.43) [56]. Unfortunately, repeated attempts to induce the Claisen rearrangement of 66 resulted in nearly complete recovery of the starting material (Eq. 3.1.44, Table 3.1.5, entry 1). With these results at hand, the microwave irradiation was attempted to induce the desired rearrangement. As a result, a small increase in yield was observed when 66 was reacted under the conditions given in Table 3.1.5, entry 2. The microwave irradiation of a solution of 68 after only 15 min resulted in a 71% yield of the desired allene 69 as a single diastereoisomer. After extensive optimization studies, it was shown that microwave irradiation with 15 consecutive 60-s pulses allowed the formation of the 69 in 88% yield. 

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