A series of novel zwitterionic phosphobetaine (PPBT) surfactants were synthesized using long chain fatty alcohol, epichlorohydrin, dimethylamine and sodium dihydrogen phosphate as raw materials. The physicochemical properties of the phosphobetaine surfactants such as isoelectric point, foaming, surface tension, critical micelle concentration (CMC) and Krafft point were measured. Low CMC and surface tension values indicated the surface activities of the phosphobetaine surfactants were quite excellent. The CMC and surface tension values of PPBT/SDS mixed systems were determined. It was found both of CMC and surface tension values decreased compared with single surfactant system because of the association between dodecyl sulfate anions and cationic groups in phosphobetaine by electrostatic attraction.

Aims. This paper aims to study the configuration of two components caused by rotational and tidal distortions in the model of a binary system. Methods. The potentials of the two distorted components can be approximated to 2nd-degree harmonics. Furthermore, both the accretion luminosity (σ i ) and the irradiative luminosity are included in stellar structure equations. Results. The equilibrium structure of rotationally and tidally distorted star is exactly a triaxial ellipsoids. A formula describing the isobars is presented, and the rotational velocity and the gravitational acceleration at the primary surface simulated. The results show the distortion at the outer layers of the primary increases with temporal variation and system evolution. Besides, it was observed that the luminosity accretion is unstable, and the curve of the energy-generation rate fluctuates after the main sequence in rotation sequences. The luminosity in rotation sequences is slightly weaker than that in non-rotation sequences. As a result, the volume expands slowly. Polar ejection is intensified by the tidal effect. The ejection of an equatorial ring may be favoured by both the opacity effect and the g e (θ, ϕ)-effect in the binary system.

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The interaction of oxygen with a Si(100)–As surface has been studied by a homemade combined surface analysis spectrometry with a molecular beam epitaxy system. This paper confirms that an As layer is a good passivation film for the Si surface and describes a study concerning all processes of oxygen adsorption on a Si(100)–As surface for the first time. It is shown that the oxygen coverage at saturation is 0.5 monolayer, i.e., adsorption sites are reduced by one-half with the existence of an As layer and the initial sticking coefficient SSi–Aso on the Si(100)–As surface was found to be 5.6×10−3, which is ten times less than that for a clean Si(100) surface. The passivating effect of the As on the Si surface is interpreted with the existence of lone-pair states instead of dangling-bond states.

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