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A conceptually novel materials design, based on crosslinked ferroelectric liquid-crystalline polymers, is demonstrated for efficient switching of a second-order nonlinear optical (NLO) response in the solid state. By controlling the molecular alignment of the NLO moieties through two-photon isomerization of azobenzene molecules, reversible isothermal photocontrol of second-harmonic generation is achieved with contrast of up to 20.

Constant-resistance active variable attentuation equalizers using a bridged T circuit are used for bilateral communication channel. Usually, the auxiliary circuits for a variable series branch impedance and a variable parallel branch impedance are constructured separately. For one variable parameter of the equalizer characteristics (such as one bump height for a bump type), one variable element is needed for series branch and the other is for parallel branch. This paper presents a method for realizing each variable impedance with a series connectio of a resistor and a variabel voltage-controlled voltage source. From the circuit analysis, it is found that both variable voltages are always related via a constant ratio. Hence, if one of the voltage sources is constructed, the other is simply its constant multiple which results in simplification of the equalizer circuit. Finally, a switched capacitor implementatio of a bumpshaped variable attenuation equalizer is presented for illustration.

Aldol reaction of aromatic acetals with alkyl enol ethers proceeds efficiently with electrogenerated acid (EG acid) independently prepared in an MeCN–NaClO4/Bu4NClO4–(Pt) system.