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Europium (Eu+) ions were confined in a Paul trap and detected by non-destructive method. Storage time of Eu+ ions achieved in vacuum was improved by orders of magnitude employing buffer gas cooling. The experimentally detected signal
was fitted to the ion response signal and the total number of ions trapped was estimated. It is found that the peak signal
amplitude as well as the product of FWHM and the peak signal amplitude is proportional to the total number of trapped ions.
The trapped ion secular frequency was swept at different rates and its effect on the absorption line profile was studied both
experimentally and theoretically. 相似文献
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Anastasia I. Solomatina Daria O. Kozina Vitaly V. Porsev Sergey P. Tunik 《Molecules (Basel, Switzerland)》2022,27(1)
Herein we report four [Ir(N^C)2(L^L)]n+, n = 0,1 complexes (1–4) containing cyclometallated N^C ligand (N^CH = 1-phenyl-2-(4-(pyridin-2-yl)phenyl)-1H-phenanthro[9,10-d]imidazole) and various bidentate L^L ligands (picolinic acid (1), 2,2′-bipyridine (2), [2,2′-bipyridine]-4,4′-dicarboxylic acid (3), and sodium 4,4′,4″,4‴-(1,2-phenylenebis(phosphanetriyl))tetrabenzenesulfonate (4). The N^CH ligand precursor and iridium complexes 1–4 were synthesized in good yield and characterized using chemical analysis, ESI mass spectrometry, and NMR spectroscopy. The solid-state structure of 2 was also determined by XRD analysis. The complexes display moderate to strong phosphorescence in the 550–670 nm range with the quantum yields up to 30% and lifetimes of the excited state up to 60 µs in deoxygenated solution. Emission properties of 1–4 and N^CH are strongly pH-dependent to give considerable variations in excitation and emission profiles accompanied by changes in emission efficiency and dynamics of the excited state. Density functional theory (DFT) and time-dependent density functional theory (TD DFT) calculations made it possible to assign the nature of emissive excited states in both deprotonated and protonated forms of these molecules. The complexes 3 and 4 internalize into living CHO-K1 cells, localize in cytoplasmic vesicles, primarily in lysosomes and acidified endosomes, and demonstrate relatively low toxicity, showing more than 80% cells viability up to the concentration of 10 µM after 24 h incubation. Phosphorescence lifetime imaging microscopy (PLIM) experiments in these cells display lifetime distribution, the conversion of which into pH values using calibration curves gives the magnitudes of this parameter compatible with the physiologically relevant interval of the cell compartments pH. 相似文献
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Eliene O Kozlowski Paula C Lima Cristina P Vicente Tito Lotufo Xingfeng Bao Kazuyuki Sugahara Mauro SG Pavão 《BMC biochemistry》2011,12(1):1-2
After the publication of the work entitled "Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfate)β-1→3GalNAc(4-Sulfate)β-1→] motifs in dermatan sulfate on heparin cofactor II activity", by Kozlowski et al., BMC Biochemistry 2011, 12:29, we found that the legends to Figures 2 to 5 contain serious mistakes that compromise the comprehension of the work. This correction article contains the correct text of the legends to Figures 2 to 5. 相似文献
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The static and dynamic electric dipole, quadrupole, and octupole polarizabilities of the alkaline-earth atoms (beryllium, magnesium, calcium, strontium, and barium) in the ground state were calculated. The dynamic polarizabilities obtained were used to calculate the van der Waals coefficients C 6, C 8, and C 10 of alkaline-earth metal dimers for the interaction of two like atoms in the ground state. The results are compared with other theoretical and experimental data. 相似文献
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A new high-precision method is used to calculate the characteristics of atoms with two valence electrons. An effective Hamiltonian
for the valence electrons is formulated by many-particle perturbation theory with respect to the residual interaction of the
valence electrons with the core. The configuration-superposition method is then used to find the energy levels of the atom.
The application of the combined method to divalent calcium, strontium, barium, and ytterbium atoms shows that the ionization
potential is obtained within 0.5% error limits. The precision attained for the first few lowest levels of the energy spectra
is significantly higher than is obtained by configuration-superposition calculations alone.
Zh. éksp. Teor. Fiz. 111, 838–846 (March 1997) 相似文献
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High-precision calculations of the 3,1 P 1 0 (ns np→1 S 0(ns 2) E1 amplitudes were carried out for magnesium, calcium, and strontium (n=3, 4, and 5, respectively). The following results were obtained for the reduced matrix element 〈1 P 1 0 ‖d‖ 1 S 0〉 of electric dipole moment operator: 4.03(2) au for Mg, 4.91(7) au for Ca, and 5.28(9) au for Sr. These matrix elements are necessary for calculating the van der Waals coefficients C 6, which are used in evaluating the atomic scattering lengths. The latter determine the dynamics and stability of the Bose-Einstein condensate. 相似文献