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Multi-wavelength observations of the black widow binary system 2FGL J2339.6-0532 are reported. The Fermi gamma-ray source 2FGL J2339.6-0532 was recently categorized as a black widow in which a recycled millisecond pulsar (MSP) is evaporating the companion star with its powerful pulsar wind. Our optical observations show clear sinusoidal light curves due to the asymmetric temperature distribution of the companion star. Assuming a simple geometry, we constrained the range of the inclination angle of the binary system to  < <  i 52 5 9, which enables us to discuss the interaction between the pulsar wind and the companion in detail. The X-ray spectrum consists of two components: a soft, steady component that seems to originate from the surface of the MSP, and a hard, variable component from the wind-termination shock near the companion star. The measured X-ray luminosity is comparable to the bolometric luminosity of the companion, meaning that the heating efficiency is less than 0.5. In the companion orbit, 10 11 cm from the pulsar, the pulsar wind is already in the particle-dominant stage with a magnetization parameter of s < 0.1. In addition, we precisely investigated the time variations of the X-ray periodograms and detected a weakening of the orbital modulation. The observed phenomenon may be related to unstable pulsar wind activity or weak mass accretion, both of which can result in the temporal extinction of the radio pulse.

The finite difference method is extended. through the use of the electrical analogue, to enable calculation of temperature distribution and heat flow in composite materials made from anisotropic materials. The standard finite difference equations have been modified on a node-by-node basis to take account of anisotropy by local re-orientation of the grid. The temperature distribution and heat tlow have been derived tor a composite material made trom two materials with anisotropic thermal conductivity. The effective thermal conductivity has been calculated for a range of different orientations of anisotropic material in samples of different rectangular shapes to illustrate the effects of sample geometry on heat transfer.

Thin films of collodion and Canada balsam have been prepared on water surfaces. Their thickness has been evaluated interferometrically over the range 4-s~ h and the relation between concentration and thickness studied. The effect of temperature on film thickness has been evaluated at 25, 100 and 150" c.

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