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51.
This paper studies the distribution of particular weighted sums of Bernoulli random variables. The computing methods are applied to derive the probability distribution of the random amount of survivor credits to be shared among surviving participants in single-period tontine schemes. The effectiveness of this new arrangement can then be evaluated beyond the classical analysis based on crude approximations for the two first moments, only. 相似文献
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54.
We study convergence in law of partial sums of linear processes with heavy-tailed innovations. In the case of summable coefficients, necessary and sufficient conditions for the finite dimensional convergence to an \(\alpha \)-stable Lévy Motion are given. The conditions lead to new, tractable sufficient conditions in the case \(\alpha \le 1\). In the functional setting, we complement the existing results on \(M_1\)-convergence, obtained for linear processes with nonnegative coefficients by Avram and Taqqu (Ann Probab 20:483–503, 1992) and improved by Louhichi and Rio (Electr J Probab 16(89), 2011), by proving that in the general setting partial sums of linear processes are convergent on the Skorokhod space equipped with the \(S\) topology, introduced by Jakubowski (Electr J Probab 2(4), 1997). 相似文献
55.
Raluca Vernic 《Journal of Theoretical Probability》2016,29(1):118-142
Built from given marginals with a flexible dependency structure, Sarmanov’s family of multivariate distributions became of interest in various fields. In this paper, we present some formulas for the density of the sum of several random variables joined by Sarmanov’s distribution, with accent on the particular case of exponentially distributed marginals. Such results are useful in solving, e.g., financial and actuarial problems. 相似文献
56.
Kenneth I. Ozoemena Raluca‐Ioana Stefan‐van Staden Tebello Nyokong 《Electroanalysis》2009,21(14):1651-1654
Novel electrochemical sensors based on carbon paste impregnated with metallopthalocyanine (MPc, M=Co, Fe) complexes, have been constructed for the assay of anti‐HIV drug 2′,3′‐dideoxyinosine (didanosine, DDI). Both modified electrodes showed electrocatalytic activity towards the oxidation of dideoxyinosine in phosphate buffer pH 7.4 with a working concentration range of 10?6–10?4 mol/L and a detection limit of 10?7 mol/L magnitude order. The sensor proved to be highly reliable for the assay of the purity of DDI ‐ raw material as well as for the uniformity content test of Videx tablets. 相似文献
57.
Zhu X Beginn U Möller M Gearba RI Anokhin DV Ivanov DA 《Journal of the American Chemical Society》2006,128(51):16928-16937
Complexes consisting of poly(4-vinylpyridine) and mesogenic wedge-shaped ligands 4'-[3",4",5"-tris(dodecyloxy)benzoyloxy]azobenzene-4-sulfonic acid and 4'-[3",4",5"-tris(octyloxy)benzoyloxy]azobenzene-4-sulfonic acid have been prepared with different monomer/ligand ratios. Upon protonation of the poly(4-vinylpyridine) chains by the wedge-shaped sulfonic acid molecules a hypsochromic and hyperchromic effect was observed with the pi-pi* transition of the azo-chromophor, allowing us to monitor the neutralization process by means of UV-vis spectroscopy in solution. The changes of the absorption characteristics implied a conformational change of the polymer backbone. In the bulk the interaction between pyridine and sulfonic acid moieties was proved by FT-IR spectroscopy. Polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction measurements were used to study the bulk structure of the complexes. The complexes formed a liquid crystalline lamellar phase at low degrees of substitution, while a hexagonal columnar mesophase was observed at degrees of neutralization of 80% and higher. 相似文献
58.
Ciuraru R Gosselin S Visez N Petitprez D 《Physical chemistry chemical physics : PCCP》2012,14(13):4527-4537
In this laboratory study, model particles of ammonium sulfate (AS) and ammonium nitrate (AN) were exposed to chlorine atoms and uptake experiments were performed in a coated wall flow tube reactor coupled to a molecular beam mass spectrometer. The reactive surfaces were prepared by coating the inner surface of the reactor using two different methods: either by depositing size-selected particles on the halocarbon wax or by spray depositing thin films using a constant output atomizer. The observed uptake coefficients vary for (NH(4))(2)SO(4), ranging from γ(Cl)(AS)≈ 1 × 10(-3) for size-selected particles to γ(Cl)(AS)≈ 6 × 10(-2) for thin films prepared by spray. An uptake coefficient of γ(Cl)(AN)≈ 2.5 × 10(-3) of Cl˙ on size-selected NH(4)NO(3) particles was measured. A heterogeneous recombination of Cl atoms to from Cl(2) molecules was observed for the two surfaces. Furthermore, an ageing process was observed for AS particles, this phenomenon leading to the formation of new chlorine species on the solid substrate. 相似文献
59.
Raluca Nicoleta Darie Mihai Brebu Cornelia Vasile Marek Kozlowski 《Polymer Degradation and Stability》2003,80(3):551-566
Binary isotactic polypropylene (IPP)/polyamide 6 (PA6) and ternary IPP/PA6/ethylene–propylene diene terpolymer (EPDM) blends in various ratios were obtained in a Haake Rheocord mixer. Processing behaviour was changed in the presence of IPP functionalized with bismaleimide (BMI), maleic anhydride (MA) and acrylic acid (AA) as reactive compatibilizing agents. The thermal and thermo-oxidative behaviour of blends was studied by differential scanning calorimetry and thermogravimetry. The functionalized IPPs modify the crystallinity degree and the decomposition behaviour of both IPP and PA6 as a result of chemical reactions of functional groups with those of the PA6. The changes depend on the IPP/PA6 or IPP/PA6/EPDM ratio, the chemical nature and amount of the functionalized IPP. On the basis of the processing and thermal data one can conclude that the compatibilizing agent effect increases in the following order: IPP-AA 相似文献
60.
Ilinca Margareta Vlad Diana Camelia Nu Robert Viorel Ancuceanu Miron Teodor Caproiou Florea Dumitrascu Ioana Cristina Marinas Mariana Carmen Chifiriuc Luminita Gabriela Mruescu Irina Zarafu Ioana Raluca Papacocea Bogdan tefan Vasile Adrian Ionu Nicoar Cornelia-Ioana Ilie Anton Ficai Carmen Limban 《Molecules (Basel, Switzerland)》2021,26(10)
Antimicrobial resistance is one of the major public health threats at the global level, urging the search for new antimicrobial molecules. The fluorene nucleus is a component of different bioactive compounds, exhibiting diverse pharmacological actions. The present work describes the synthesis, chemical structure elucidation, and bioactivity of new O-aryl-carbamoyl-oxymino-fluorene derivatives and the contribution of iron oxide nanoparticles to enhance the desired biological activity. The antimicrobial activity assessed against three bacterial and fungal strains, in suspension and biofilm growth state, using a quantitative assay, revealed that the nature of substituents on the aryl moiety are determinant for both the spectrum and intensity of the inhibitory effect. The electron-withdrawing inductive effect of chlorine atoms enhanced the activity against planktonic and adhered Staphylococcus aureus, while the +I effect of the methyl group enhanced the anti-fungal activity against Candida albicans strain. The magnetite nanoparticles have substantially improved the antimicrobial activity of the new compounds against planktonic microorganisms. The obtained compounds, as well as the magnetic core@shell nanostructures loaded with these compounds have a promising potential for the development of novel antimicrobial strategies. 相似文献