Correlation coefficients (r) are shown for organochlorine concentrations (ng l −1 ) in snow and site elevation (m.a.s.l.) for the equation conc: ¼ ae b Elev: , where a and b are fitted constants. Asterisks show significance at P р 0:05, for 19 degrees of freedom. Sub-cooled liquid vapour pressures are included for pesticides at 20 ЊC (ref. 21) and PCBs at 25 ЊC (ref. 22). Published vapour pressures vary considerably, so these values represent mean reported values for all PCBs in that class. Ranges of published vapour pressures for each PCB category are shown in brackets.Only compounds with mean sample concentrations that were ten times higher than blanks were considered. † Present addresses:

Highly polarized electroluminescence from a liquid‐crystal polymer device, based on a branched polyfluorene with a branched side chain, is demonstrated here as a further step towards the use of organic electroluminescent (EL) devices as backlights in conventional liquid‐crystal displays. The modification of a polyimide (PI) for hole conduction by addition of a suitable filler at moderate concentration is reported and the performance of a device containing such a rubbed, hole‐conductor‐filled PI layer as the alignment layer is compared with that of a device with a PI‐only alignment layer.

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