Zhou Jin | PubMed Health

PubMed2002

Electron-donating properties of p-phenylene phosphine imides: an electrochemical and spectroscopic investigation.

[reaction: see text] Electronic properties of phosphine imide based organic electron donors have been investigated. N,N'-p-Phenylenebis(triphenyl)phosphine imide (Ph(3)P=NC(6)H(4)N=PPh(3), 1) has two reversible single-electron oxidations (0.04 and 0.53 V vs SCE). Spectroscopic investigations of poly(p-phenylene phosphine imide)s (2) are similar to those of polymer model compounds, suggesting formation of localized radical cations on the polymer chains and electronically insulating phosphorus atoms.

Journal Article↗

PubMed2002

Self-focusing hidden bar code.

A new type of diffractive optical bar code produced by computer-generated holographic technology is proposed. The message in the proposed bar code is hidden in the diffracted light of the bar code element and can be read from the first diffraction order. In contrast to the conventional hidden bar code, which needs a lens to focus the diffracted light, the proposed hidden bar code has a property of self-focusing. This self-focusing ability is achieved by modulating a function of the Fresnel zone plate into the bar code format. Consequently, the read-out process for the information in this hidden bar code avoids the use of a lens. Experiments have shown the feasibility of the proposed bar code and confirmed that it can perform better than the conventional hidden bar code.

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