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521.
Agnieszka Dżaluk Dariusz Malczewski Jerzy Żaba Maria Dziurowicz 《Journal of Radioanalytical and Nuclear Chemistry》2018,316(1):101-109
The natural radioactivities of five characteristic igneous rocks of the eastern foreland of the Opava Mountains (Eastern Sudetes, Poland), obtained in the laboratory and under in situ conditions, are presented. The activity concentrations of 232Th, 238U, and 40K were measured using an HPGe gamma-ray spectrometry system. The ranges of the activity concentrations of 232Th were 7–71 Bq kg?1 in the laboratory and 6–68 Bq kg?1 for the in situ measurements. For 238U, the ranges of the activity concentrations were 5–52 Bq kg?1 in the laboratory and 9–48 Bq kg?1 for the in situ measurements, and for 40K, the ranges were 520–1560 Bq kg?1 in the laboratory and 537–1700 Bq kg?1 for the in situ measurements. These determined activity concentrations were compared with the average activity concentrations of the radionuclides in similar types of rocks and with data from the Sudetes available in the literature. No significant differences were found between the in situ and laboratory measurements. 相似文献
522.
Photoinduced dissociation of two Mo-CN bonds in [Mo(CN)8]4- affords the octahedral complex anion [Mo(CN)6]2-. This hexacyanomolybdate(IV) ion is also obtainable from tetracyanooxomolybdate via a thermal substitutional synthetic route. The anion represents the missing link in the ligand-field photolysis of octacyanomolybdate(IV); it is characterized by means of single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic susceptibility measurements as well as IR, Raman, 1H and 13C NMR, and electronic spectroscopy. 相似文献
523.
Complexation of iron(III) with the heterodonor chelating agent 3,5-di-tert-butylsalicylidene benzoylhydrazine, H2(3,5-tBu2)salbh, in the absence or presence of a base affords the complex cation [Fe{H(3,5-tBu2)salbh}2]+ or the neutral compound [Fe{H(3,5-tBu2)salbh}{(3,5-tBu2)salbh}], respectively, as revealed by single-crystal X-ray analyses. Such a synthetic and crystallographic demonstration of the coordination versatility of an aroylhydrazone toward iron is uncommon. The oxidation and spin states of the iron have been verified with magnetic and spectroscopic measurements. 相似文献
524.
Explicitly correlated Gaussian functions have been used to perform very accurate variational calculations for the ground states of (7)Li and (7)Li(-). The nuclear motion has been explicitly included in the calculations (i.e., they have been done without assuming the Born-Oppenheimer (BO) approximation). An approach based on the analytical energy gradient calculated with respect to the Gaussian exponential parameters was employed. This led to a noticeable improvement of the previously determined variational upper bound to the nonrelativistic energy of Li(-). The Li energy obtained in the calculations matches those of the most accurate results obtained with Hylleraas functions. The finite-mass (non-BO) wave functions were used to calculate the alpha(2) relativistic corrections (alpha=1c). With those corrections and the alpha(3) and alpha(4) corrections taken from Pachucki and Komasa [J. Chem. Phys. 125, 204304 (2006)], the electron affinity (EA) of (7)Li was determined. It agrees very well with the most recent experimental EA. 相似文献
525.
Dariusz R. Kowalski Eyal Nussbaum Michael Segal Vitaly Milyeykovsky 《Optimization Letters》2014,8(2):777-799
In this paper we consider online scheduling problems for linear topology under various objective functions: minimizing the maximum completion time, minimizing the largest delay, and minimizing the sum of completion times. We give optimal solutions for uni-directional version of the problem for each of the objectives and show that for the two-directional versions of each problem, no online algorithm can deterministically achieve the optimal solution for any of the considered objective functions. We also propose 2-approximation on-line algorithms for the MinMakespan and the MinSum minimization objectives. We also prove that no online algorithm can deterministically achieve the optimal solution for any of the considered objective functions for the weighted case of uni-directional scenarios. 相似文献
526.
We have developed a new method for the synthesis of functionalized symmetrical trisulfides based on (5,5‐dimethyl‐2‐thioxo‐1,3,2‐dioxa‐phosphorin‐2‐yl)disulfanyl derivatives prepared from readily available 5,5‐dimethyl‐2‐sul‐fanyl‐2‐thioxo‐1,3,2‐dioxaphosphorinane or bis(5,5‐dimethyl‐2‐thioxo‐1,3,2‐dioxaphosphorinan‐2‐yl) disulfide. The symmetrical trisulfides can be obtained from aliphatic and aromatic thiols and l ‐cysteine derivatives under mild conditions with high yield and purity. 相似文献
527.
Piotr Martyniuk Waldemar Gawron Wioletta Pusz Dariusz Stanaszek Antoni Rogalski 《Optical and Quantum Electronics》2014,46(10):1303-1312
The paper reports on photoelectrical performance of the mid-wave infrared (MWIR) (111) HgCdTe high operating temperature detector for the fast response conditions. Detector structure was simulated with software APSYS by Crosslight Inc. The detailed analysis of the time response as a function of device architecture and applied voltage was performed pointing out optimal working conditions. The time response of the MWIR HgCdTe detector with 50 % cut-off wavelength of \(\lambda _{c} \approx 5.3\, \upmu \hbox {m}\) at \(T = 200\) K was estimated at the level of \(\tau _{s} \approx \) 2,500 ps for \(V = 100\) mV and series resistance \(R_{Series} = 510\,\Omega \) . The series resistance’s reduction enables to reach \(\tau _{s}\approx 60\!-\!500\) ps. 相似文献
528.
We show that, under suitable confinement conditions, the ordinary Fokker-Planck equation may generate non-Gaussian heavy-tailed probability density functions (pdfs) (like, for example, Cauchy or more general Lévy stable distributions) in its long-time asymptotics. In fact, all heavy-tailed pdfs known in the literature can be obtained this way. For the underlying diffusion-type processes, our main focus is on their transient regimes and specifically the crossover features, when an initially infinite number of pdf moments decreases to a few or none at all. The time dependence of the variance (if in existence), ∼tγ with 0<γ<2, may in principle be interpreted as a signature of subdiffusive, normal diffusive or superdiffusive behavior under confining conditions; the exponent γ is generically well defined in substantial periods of time. However, there is no indication of any universal time rate hierarchy, due to a proper choice of the driver and/or external potential. 相似文献
529.
530.
Dariusz Cichoń 《Journal of Mathematical Analysis and Applications》2011,380(1):94-104
The aim of this paper is to analyze a “support-free” version of the Riesz-Haviland theorem proved recently by the present authors, which characterizes truncations of the complex moment problem via positivity condition on appropriate families of polynomials in z and . The attention is focused on modifications of the positivity condition as well as the assumption on admissible truncations. The former results in truncations for which the corresponding “support-free” Riesz-Haviland condition locates a representing measure on the distinguished subset of the complex plane, while the latter effects a non-integral variant of the Riesz-Haviland theorem. 相似文献