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An analytical methodology has been developed for the UV-spectrophotometric determination of carbaryl in waters after its preconcentration onto a polyether type polyurethane foam followed by on-line elution. The aforementioned strategy offers an easy way for in-field sampling and to improve the analytical sensitivity. Several chemical and flow variables (mass of sorbent, sample flow rate, sample volume and carrier flow rate) were studied to ensure the best performance of the system. Recovery studies, carried out on natural water samples spiked with known amounts of carbaryl at concentration levels between 250 and 500 mug l(-1), provided recovery percentages between 94 and 105%. A detection limit of 12 mug l(-1) was achieved and a variation coefficient of 3.4% was obtained at 0.50 mug ml(-1). 相似文献
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M. Lindroos P. Richards J. Rikovska N. J. Stone I. Oliveira K. Nishimura M. Booth 《Hyperfine Interactions》1992,75(1-4):323-330
A low temperature nuclear orientation experiment has been performed on the 14.8d225Ra activity. Gamma anistotropy [221Fr (4.8m) and213Bi (45.6m)] and alpha anisotropy [225Ac (10.0d),221Fr,217At (32.3ms) and209Po (4.2μs)] measurements has been carried out and values for the hyperfine field of225Ac and221Fr in iron and the magnetic moment of213Bi are reported. 相似文献
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M. Lindroos P. Richards J. Blomqvist J. Rikovska N. J. Stone 《Hyperfine Interactions》1992,75(1-4):109-116
The magnetic dipole moments of212Bi and213Bi have been measured and the results are interpreted within the framework of the shell model. 相似文献
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The formation of small angle boundaries consisting of dislocation networks is considered mainly on the basis of studies concerning the hot-deformation of Al-Mg alloys solidified with well developed sub-structures. It is shown that different kinds of network are built up on dislocation forests by dislocations which encounter the forest by glide and then change the mode of motion from glide to climb. Special attention is given to the mechanism of climb which enables the rapid knitting of networks during hot-deformation, and also to the annihilation of dislocations which prevents the increase in flow stress. 相似文献
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Angle-resolved energy distribution curves of photoelectrons obtained at constant wavevector component k6 have been presented for the surface of Cu(111). The main observed transitions can be interpreted as due to direct interband transitions between the APW initial states and free-electron-like final states which are calculated simply in one-dimension along k⊥ lines parallel to the surface normal. 相似文献
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B. A. Marsh L.-E. Berg D. V. Fedorov V. N. Fedosseev O. J. Launila M. Lindroos R. Losito F. K. ?sterdahl T. Pauchard I. T. Pohjalainen U. Sassenberg M. D. Seliverstov A. M. Sj?din G. Transtr?mer 《Hyperfine Interactions》2010,196(1-3):129-141
On account of its high efficiency, speed and unmatched selectivity, the Resonance Ionization Laser Ion Source (RILIS) is the preferred method for ionizing the nuclear reaction products at the ISOLDE on-line isotope separator facility. By exploiting the unique electronic energy level ‘fingerprint’ of a chosen element, the RILIS process of laser step-wise resonance ionization enables an ion beam of high chemical purity to be sent through the mass selective separator magnet. The isobaric purity of a beam of a chosen isotope is therefore greatly increased. The RILIS, comprising of up to three frequency tunable pulsed dye lasers has been upgraded with the installation of a Nd:YAG pump laser as a replacement for the old Copper Vapor Laser (CVL) system. A summary of the current Nd:YAG pumped RILIS performance is given. To accompany the RILIS pump laser upgrade, a new ionization scheme for manganese has been developed at the newly constructed LAser Resonance Ionization Spectroscopy (LARIS) laboratory and successfully applied for on-line RILIS operation. An overview of the LARIS facility is given along with details of the ionization scheme development work for manganese. 相似文献
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We derive photoelectron selection rules along the glide plane in orthorhombic Bi2Sr2CaCu2O8+delta (Bi2212). These selection rules explain the reversed intensity behavior of the shadow and the main band of the material as a natural consequence of the variating representation of the final state as a function of k(parallel). Our one-step simulations strongly support the structural origin of the shadow band but we also introduce a scenario for detecting antiferromagnetic signatures in low doping. 相似文献