Direct current pulse

Selective synthesis of acetylene (>90%) from methane was accomplished by microwave plasma reactions.568 Conversion of methane to acetylene by using direct current pulse discharge was performed under conditions of ambient temperature and atmospheric pressure.569 The selectivity of acetylene was >95% at methane conversion levels ranging from 16 to 52%. In this case oxygen was used to effectively remove deposited carbon and stabilize the state of discharge. Similar high... 

Bond, A.M., Czerwinski, W.A. and Llorente, M. (1998) Comparison of direct current, derivative direct current, pulse and square wave voltammetry at single disc, assembly and composite carbon electrodes stripping voltammetry at thin film mercury microelectrodes with field-based instrumentation. Analyst, 123, 1333-1337. 

Lammert, S.A. eleven, C.D. Cooks, R.G. Determination of ion frequencies in a quadrupole ion-trap by using a fast direct-current pulse as pump and a laser probe. J. Am. Soc. Mass Spectrom. 1994, 5, 29-36. 

R. K. Julian, M. Nappi, C. Weil, and R. G. Cooks, Multiparticle simulation of ion motion in the ion trap mass spectrometer resonant and direct current pulse excitation, 7. Am. Soc. Mass Spectrom. 6, 57-70 (1995). 

In temperature modulation, the sample may be mounted on a small heater attached to a heat sink and the temperature varied cyclically by passing current pulses through the heater. If the sample is properly conducting, the current can be passed through the sample directly. Generally, for this method must be kept below 10—20 Hz, and hence there are often problems with the 1//"noise of the detector. 

Nonlinear properties of normal dielectrics can be studied in the elastic regime by the method of shock compression in much the same way nonlinear piezoelectric properties have been studied. In the earlier analysis it was shown that the shape of the current pulse delivered to a short circuit by a shock-compressed piezoelectric disk was influenced by strain-induced changes in permittivity. When a normal dielectric disk is biased by an electric field and is subjected to shock compression, a current pulse is also delivered into an external circuit. In the short-circuit approximation, the amplitude of this current pulse provides a direct measure of the shock-induced change in permittivity of the dielectric. 

DC = direct current NP = normal pulse DP = differential pulse SW = square wave AC = alternating... 

Furthermore, it was shown the unpaired spin S = 1/2, which is delocalized over the two Pc rings, still remained in the Jt-orbitals after absorption on Au(lll). Consequently, STS measurements also provided direct observation ofthe S = 1/2 radical on the TbPc2 molecules on Au(lll) whereby the indicative Kondo-peak could be switched off by tunnelling current pulses [215]. Indeed the tunnelling conductance (dl/dV) was analysed from STS experiments of TbPc2 on Au(lll) near the Fermi level showed a zero-bias peak (ZBP) in the spectra, which could be assigned as a Kondo resonance. Clear Kondo features for the molecules with 9 = 45° were observed when the tip was positioned over one ofthe lobes of TbPc2. 

Studies using a differential-pulse polarographic technique, which is recommended in place of classical direct current polarography, yielded the following results. For... 

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