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31.
Wael M. Badawy Octavian G. Duliu Marina V. Frontasyeva Hussein El Samman Arnaud Faanhof 《Isotopes in environmental and health studies》2018,54(5):535-547
The activity concentrations of natural 40K, 232Th, and 238U in 89 soil and 84 sediment samples collected over the entire Egyptian Nile River basin including the Nile delta are reported based on the results of epithermal neutron activation analysis. The average activity concentrations of 40K, 232Th, and 238U equal to 15.3?±?6.6, 15.6?±?11.1 and 220?±?31 Bq/kg, respectively, are significantly lower than those reported for the Upper Continental Crust, World Average Sediments as well as World Average Soils, suggesting the presence of a considerable portion of mafic material, most probably originating from the Ethiopian High Plateau. Their average activity concentrations are statistically the same in soil and sediments, indicating that the Nile sediments and soil material are of the same origin. The main goal of this study was not only to estimate the radiological hazards but also to show the influence of sedimentary material transportable by the Blue Nile from the Ethiopian High Plateau. The different hazard indices like the radium equivalent, gamma index, external hazard as well as the internal hazard show a low radiological exposure either on direct contact or if local mud bricks are used in the construction of dwellings. 相似文献
32.
Marina Davydova Alexander Kromka Oleg Babchenko Karel Hruska 《Applied Surface Science》2010,256(18):5602-1312
Diamond nanorods were fabricated for a sensing device by utilizing reactive ion etching in CF4/O2 radio frequency plasma. The length of the nanorods has been controlled by the ion etching time. The obtained morphologies were investigated by scanning electron microscopy. The gas sensing properties of the H-terminated diamond-based sensor structures are indicating that we have achieved high sensitivity to detect phosgene gas. Also, our sensor exhibited good selectivity between humid air and phosgene gas if the measurement is conducted at elevated temperatures, such as 140 °C. Furthermore, such sensor response rating could reach as high value as 4344 for the phosgene gas, which was evaluated for the sample consisting of the longest nanorods (up to 200 nm). 相似文献
33.
Alexander Vasin Marina Dolmatova Gerhard-Wilhelm Weber 《Central European Journal of Operations Research》2016,24(4):819-831
We consider game-theoretic models related to the supply function auction for electricity markets. We determine the set of supply function equilibria (SFE), introduced by Klemperer and Mayer (Econometrica 57:1243–1277, 1989), for a symmetric oligopoly with linear demand, fixed marginal cost and capacity constraint. This set depends on the maximum random shock of the demand function. We also study the best response dynamics and show that in general it does not converge to any SFE. We find out sufficient conditions for the convergence and conclude on the optimal parameters of the auction. 相似文献
34.
Alexandre Brouste Marina Kleptsyna Alexandre Popier 《Statistical Inference for Stochastic Processes》2012,15(2):133-149
We consider a controlled linear differential equation which is partially observed with an additive fractional noise. In this setting, we study the asymptotic (for large observation time) design problem of the input and give an efficient estimator of the unknown signal drift parameter. The optimal estimation input is deduced. The consistency, asymptotic normality and convergence of the moments of the MLE are established. 相似文献
35.
The hyperfine lines of the forbidden Γ34?→?Γ34 optical transition are observed in the axially polarized absorption spectra of Ho3+ in LiYF4. They are explained by an admixture of nearby lying Γ2 and Γ1 crystal field states by the perpendicular part of the magnetic dipole hyperfine interaction. 相似文献
36.
Igor Tkach Karin Halbmair Claudia Höbartner Marina Bennati 《Applied magnetic resonance》2014,45(10):969-979
Pulsed electron–electron double resonance (PELDOR/DEER) at high frequencies can provide information on the relative orientation of paramagnetic centres or spin labels, if those are rigidly oriented in a host biomolecule and experiments are performed with sufficient orientation selectivity. We present the first comparative PELDOR study at 263 and 94 GHz on a model RNA system containing rigid nitroxides. We show that at 263 GHz still considerable modulation depth is observed and orientation selectivity is significant, particularly in g x–g y plane of the nitroxides. 相似文献
37.
38.
Indranil Biswas Tomás L. Gómez Norbert Hoffmann Marina Logares 《Communications in Mathematical Physics》2009,290(1):357-369
Fix integers g ≥ 3 and r ≥ 2, with r ≥ 3 if g = 3. Given a compact connected Riemann surface X of genus g, let denote the corresponding Deligne–Hitchin moduli space. We prove that the complex analytic space determines (up to an isomorphism) the unordered pair , where is the Riemann surface defined by the opposite almost complex structure on X. 相似文献
39.
Marina T. Primatarowa Radostina S. Kamburova 《Central European Journal of Physics》2012,10(5):1102-1108
We present a study of the ferromagnetic spin chain with both first- and second-neighbor interactions. We obtain the condition for the appearance and stability of bright and dark solitons for arbitrary wave number in the Brillouin zone. The influence of the second-neighbor interaction and the anisotropy on the soliton properties is considered. The scattering of dark solitons from point defects in the discrete spin chain is investigated numerically. 相似文献
40.
Gerasko OA Mainicheva EA Naumova MI Neumaier M Kappes MM Lebedkin S Fenske D Fedin VP 《Inorganic chemistry》2008,47(19):8869-8880
Sandwich-type lanthanide complexes with macrocyclic ligand cucurbit[6]uril (C 36H 36N 24O 12, CB[6]) were synthesized under hydrothermal conditions from aqueous solutions of lanthanide(III) bromides, CB[6], and 4-cyanopyridine. According to X-ray analysis (Ln = La, Pr, Dy, Ho, Er, and Yb), the compounds with different structural types of lanthanide cores have a common fragment where the tetranuclear hydroxo complex is sandwiched between two macrocycles {(IN@CB[6])Ln 4(mu 3-OH) 4(IN@CB[6])} (6+) (IN = isonicotinate). The photoluminescence (for Ln = Eu) and Fourier transform ion cyclotron resonance mass spectra (for Ln = Pr, Dy, and Er) were studied. The compounds are used for the first time as precursors for the synthesis of lanthanide-silver heterometallic coordination polymers. The chainlike crystal structure of polymers (Ln = La, Pr, and Dy) is constituted by the sandwich complexes linked via the coordination of IN nitrogen atoms to the silver atoms. 相似文献