The properties of the nonlinear frequency shift (NFS), especially the fluid NFS from the harmonic generation of the ion-acoustic wave (IAW) in multi-ion species plasmas, have been researched by Vlasov simulation. Pictures of the nonlinear frequency shift from harmonic generation and particle trapping are shown to explain the mechanism of NFS qualitatively. The theoretical model of the fluid NFS...

A simple, accurate and fast vortex-assisted dispersive liquid-liquid microextraction procedure has been developed for the extractive spectrophotometric determination of niflumic acid in biological samples. The method is based on the formation of an ion association complex between niflumic acid and methylene blue. The resulting ion-pair was extracted into dichloromethane and its absorbance was m...

1. Native species might be able to persist in the face of a detrimental exotic invader by occupying refuge habitats where the exotic is not successful. These refuges might then provide demographic subsidies that enhance persistence of the native species in areas of coexistence with the exotic species. Phenotypic plasticity of the native species could play a critical role in this process by allo...

We demonstrate that 3 keV ion beams, formed from the common noble gasses, He, Ne, Ar, Kr, and Xe, can controllably "sculpt" nanometer scale pores in silicon nitride films. Single nanometer control of structural dimensions in nanopores can be achieved with all ion species despite a very wide range of sputtering yields and surface energy depositions. Heavy ions shrink pores more efficiently and m...

We calculate the ion distributions around an interface in fluid mixtures of highly polar and less polar fluids (water and oil) for two and three ion species. We take into account the solvation and image interactions between ions and solvent. We show that hydrophilic and hydrophobic ions tend to undergo a microphase separation at an interface, giving rise to an enlarged electric double layer. We...

A new sensitive and selective spectrophotometric method for the determination of iron using a PVC membrane containing bathophenanthroline and dioctylphethalate as the solid phase extraction medium is investigated. Fe(II) in an aqueous sample solution is trapped on the membrane with an anion species, picrate ion and forms a complex with bathophenanthroline. The absorbance of the red-orange m...

The formation constants of the species formed in the systems H+ + cytidine 5-monophosphate (CMP)and H+ + cytidine 5-monophosphate + Tl (I) ion have been determined in aqueous solution in a widepH range of 1.5 to 10.5 at 25 °C and different ionic strengths ranging from 0.1 to 1.5 moldm-3NaClO4, NaNO3, and NaCl using potentiometric-spectrophotometric technique. The composition ofthe complexes was...

Nematologists frequently encounter congeneric species in sampling for nematodes. No convenient method for the separat ion of morphological ly similar species has been described. For Meloidogyne spp., inoculum consisting of hundreds of eggs can be easily obta ined from a single egg mass and a pure popula t ion reared on a suitable host. T h e separation and culture of other plantparasitic nemato...