Results 1 - 10 of 339052
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[en] New observations of the 3s23p 2P-3s3p24P intercombination transitions in Al-like ions have been made for Cl V from spark spectra recorded at Lund and for Kr XXIV and Mo XXX from spectra obtained at the JET tokamak. The new results have been combined with other identifications of these transitions along the sequence and empirically systematized and compared with theoretical calculations. A set of smoothed and interpolated values for the excitation energies of the 3s3p24P levels in P III-Mo XXX is presented. (orig.)
[en] Each beryllium-like ion is considered in turn, from Z = 4 to 28 (Be I to Ni XXV). References are given for the main electron impact excitation calculations performed (for example, Coulomb-Born, distorted-wave, and R-matrix calculations), in chronological order, noting whether tabular data (for example, collision strengths, rates, fits) are available. Comparisons of the thermally averaged effective collision strengths are made for three Δn = 0 and one Δn = 1 sample transitions for the even-charged ions. The most accurate data come from large R-matrix calculations which explicitly include configuration interactions, resonances, channel coupling associated with n ≤ 3 states, and, at higher Z, relativistic effects. Only a few ions have been treated in such a sophisticated way; further work will therefore be necessary if reliable data are required across the isoelectronic sequence. Recommendations are made for the best currently available for each ion. 50 refs., 12 figs
[en] Electron cyclotron resonance ion source (ECRIS) development has progressed with multiple-frequency plasma heating, higher mirror magnetic fields, and better technique to provide extra cold electrons. Such techniques greatly enhance the production of highly charged ions from ECRISs. So far at continuous wave (CW) mode operation, up to 300 eμA of O7+ and 1.15 emA of O6+, more than 100 eμA of intermediate heavy ions for charge states up to Ar13+, Ca13+, Fe13+, Co14+, and Kr18+, and tens of eμA of heavy ions with charge states to Kr26+, Xe28+, Au35+, Bi34+, and U34+ were produced from ECRISs. At an intensity of at least 1 eμA, the maximum charge state available for the heavy ions are Xe36+, Au46+, Bi47+, and U48+. An order of magnitude enhancement for fully stripped argon ions (I≥60enA) were also achieved. This article will review the ECR ion source progress and discuss key requirement for ECRISs to produce the highly charged ion beams. copyright 1998 American Institute of Physics
[en] Development of a selective and sensitive sensor for Ba"2"+ is currently of great importance because of the adverse effects of Ba"2"+ on the human body. In this study, we developed an excellent fluorescence chemosensor for Ba"2"+ based on 3AP (N-salicylidene-3-aminopyridine). A fluorescence spectrophotometer is utilized to investigate the sensing properties of 3AP, and the results indicate that 3AP shows sensitive and selective detection of Ba"2"+ through the enhancement of fluorescence intensity. The detection limit is determined to be 7.08×10"−"7 mol/L. Background metal ions, such as Li"+, Na"+, K"+, Cs"+, Ca"2"+, Mg"2"+, Mn"2"+, Fe"3"+, Fe"2"+, Co"2"+, Ni"2"+, Cu"2"+, Zn"2"+, Pb"2"+, Cd"2"+, Al"3"+ and Ag"+, exhibit small or no interference with the detection of Ba"2"+. - Highlights: • A fluorescent chemosensor for Ba"2"+ was developed. • The effect of the molecular structure on metal ion detection was investigated. • The sensor has the advantages of high selectivity, high sensitivity and easy preparation
[en] Highlights: → Investigated M2+ ions: Be2+, Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+. → Investigated M3+ ions: Ga3+, Y3+, La3+, Gd3+, and Lu3+. → Properties of ions are related to charge density of ion and first solvation number. - Abstract: Densities of the solutions of gallium, yttrium, lanthanum, gadolinium, and lutetium trifluoromethanesulfonates in methanol have been determined at temperatures ranging from (283.15 to 313.15) K. The sound velocities in these systems have been measured at T = 298.15 K. From obtained data the standard partial molar volumes and their temperature derivatives as well as standard partial molar adiabatic compressibilities for ions in solutions have been estimated. The results have been discussed on the basis of the classical model of ion in solution and compared with our earlier findings for divalent cations. The importance of the numbers of solvent molecules in first solvation spheres of ions has been revealed.
[en] Calculations of collision strengths for fluorine-like ions, using close-coupling and distorted-wave approximations, have been carried out by various authors. Effective collision strengths at a number of electron temperatures have been calculated from the available data and these results are presented in this paper. Recommended results are indicated and suggestions for future work are given. 41 refs., 27 figs., 22 tabs
[en] Polyurethane network 1 was prepared through curing of epoxy-based polymer bearing 1-naphthylamine units with tolylene-2,4-diisocyanate as curing agent. With ferric ions, the network was found to exhibit selective ON–OFF-type fluorescence signaling behavior even in the presence of other representative metal ions such as Na+, K+, Ag+, Cu2+, Zn2+, Co2+, Ni2+, Cd2+, Hg2+, Mg2+, Sr2+, Pb2+ and Ca2+ ions.