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1.
Taketatsu T 《Talanta》1982,29(5):397-400
The fluorescence intensities of terbium, europium and samarium complexes with several beta-diketone derivatives in the absence and presence of tri-n-octylphosphine oxide (TOPO) in micellar solution of nona-oxyethylene dodecyl ether (BL-9EX) were examined. The spectrophotofluorimetric determination of terbium (1.5-1500 ng/ml) has been investigated with pivaloyltrifluoroacetone (PTA) and TOPO in 0.5% micellar solution (pH 3.8-4.5) of BL-9EX. The excitation and emission wavelengths were 309 and 542 nm, respectively. Europium and samarium could be determined by a similar method. 相似文献
2.
The absorption spectra of europium-Tiron complexes in aqueous solution have been measured from 340 to 600 nm. The absorbance at 390 and 420 nm follows Beer's law up to 0.8 mg ml (pH 6.2-6.6). Other rare earths except for cerium(III) did not interfere. The interference of cerium could be removed by addition of ascorbic acid. The combining ratio of Tiron to europium has been found to be 1:1. 相似文献
3.
Preparation and characterization of single-phase SiC nanotubes and C-SiC coaxial nanotubes 总被引:2,自引:0,他引:2
Tomitsugu Taguchi Naoki Igawa Hiroyuki Yamamoto Shin-ichi Shamoto Shiro Jitsukawa 《Physica E: Low-dimensional Systems and Nanostructures》2005,28(4):431-438
Preparation conditions of single-phase SiC nanotubes and C-SiC coaxial nanotubes were investigated. The characterization of single-phase SiC nanotubes and C-SiC coaxial nanotubes were carried out. The SiC nanowires, which were made of the catenated SiC grains of 50–200 nm in diameter, were obtained in carbon nanotubes reacted at 1450 °C. The only C-SiC coaxial nanotubes were formed at 1300 °C. A few single-phase SiC nantoubes were synthesized at 1200 °C for 100 h. More than half number of nanotubes reacted at 1200 °C for 100 h were altered to single-phase SiC nantoubes by heat treatment of 600 °C for 1 h in air since the remained carbon was removed. The energy dispersive X-ray spectroscopy analysis revealed that the atomic ratio of Si to C in single-phase SiC nanotubes was almost 1; these single-phase SiC nanotubes consisted of near-stoichiometric SiC grains. 相似文献
4.
The dstribution ratio of europium(III) with a β-diketone and a neutral adduct between micellar and bulk phases in aqueous nonionic surfactant solution was measured by a spectrofluorimetric method as a function of hydrogen ion concentration. The synergic effect of trioctylphosphine oxide for the various β-diketone chelates is much greater than that of tributyl phosphate. 相似文献
5.
The absorption spectra of neodymium, holmium and erbium Tiron complexes in aqueous solution have been measured from 340 to 650 nm. The absorbance at the wavelength of maximum absorption band of an aqueous medium containing neodymium (pH 4.5), neodymium (pH 12.0), holmium (pH 5.0) and erbium (pH 5.0) Tiron complexes was about 4 (at 578 nm), 9 (at 571 nm), 9 (at 450 nm) and 5 (at 376 nm) times greater, respectively, than for the same quantities of the corresponding chlorides. The spectrophotometric determination of these elements has been investigated. Combining ratios of Tiron to rare earth have been found to be 3:2 and 2:1. 相似文献
6.
The conditions for the spectrophotofluorometric determination of terbium and europium, in solutions of potassium carbonate, have been established. The apparent excitation and fluorescence wavelengths used, respectively, are 245 mmu and 550 mmu for terbium and 400 mmu and 620 mmu for europium. The fluorescence varies linearly with the concentration of terbium and europium in the range 0.3-70 mug, of terbium/ml and 4-800 mug of europium/ml. Large amounts of gadolinium, lutetium and yttrium do not interfere. Cerium(IV) interferes seriously. 相似文献
7.
The rare-earth chlorophosphonazo III chelates are easily extracted from an aqueous solution (pH 1.1-1.5) into n-butanol. The absorbance at the absorption maximum (at 668 nm) is about 3 times that in aqueous solution. The spectrophotometric determination of rare earths has been investigated. 相似文献
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9.
The solubilities and anion-exchange behavior of rare earth elements in potassium carbonate solutions
The solubilities of rare earth elements (La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er,Tm, Yb,Lu andY) in potassium carbonate solution, and the distribution coefficients of the rare earth ions between the carbonate solution and Dowex I resin were measured. The values obtained show a variation that depends on the concentration of potassium carbonate and atomic number. There is a clearly different tendency in these values between La-Ho and Er-Lu. 相似文献
10.
We report a one-pot biological approach to fabricate gold nanoparticle (AuNP)-ZZ domain conjugates using peptide-functionalized proteins that can simultaneously direct both biomineralization and surface modification of AuNPs. In addition, immuno-AuNPs are readily prepared through the specific binding of antibodies to the ZZ domain on the AuNPs. 相似文献