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XPS determination of the oxygen coefficient kO= 2 + xand ionic (U4+, U5+, and U6+) composition of oxides UO2+xformed on the surfaces of differently oriented (hkl) planes of thin UO2films on LSAT (Al10La3O51Sr14Ta7) and YSZ (yttria-stabilized zirconia) substrates was performed. The U 4f and O 1s core–electron peak intensities as well as the U 5f relative intensity before and after the 129Xe23+and 238U31+irradiations were employed. It was found that the presence of uranium dioxide film in air results in formation of oxide UO2+xon the surface with mean oxygen coefficients kOin the range 2.07–2.11 on LSAT and 2.17–2.23 on YSZ substrates. These oxygen coefficients depend on the substrate and weakly on the crystallographic orientation. On the basis of the spectral parameters it was established that uranium dioxide films AP2,3 on the LSAT substrates have the smallest kOvalues, and from the XRD and EBSD results it follows that these samples have a regular monocrystalline structure. The XRD and EBSD results indicate that samples AP5–7 on the YSZ substrates have monocrystalline structure; however, they have the highest kOvalues. The observed difference in the kOvalues was probably caused by the different nature of the substrates: the YSZ substrates provide 6.4% compressive strain, whereas (001) LSAT substrates result only in 0.03% tensile strain in the UO2films. 129Xe23+irradiation (92 MeV, 4.8 × 1015ions/cm2) of uranium dioxide films on the LSAT substrates was shown to destroy both long-range ordering and uranium close environment, which results in an increase of uranium oxidation state and regrouping of oxygen ions in uranium close environment. 238U31+(110 MeV, 5 × 1010, 5 × 1011, 5 × 1012ions/cm2) irradiations of uranium dioxide films on the YSZ substrates were shown to form the lattice damage only with partial destruction of the long-range ordering.

The results of X-ray photoelectron spectroscopy (XPS) studies of the structures of the outer and inner electron shells of compounds of light actinides (Th, U, Np, Pu, Am, Cm, Bk, Cf) in the binding energy (Eb) range of 0–1250 eV are generalised. The regularities of formation of the fine structure in the X-ray photoelectron (XPS) spectra of these compounds are considered. The mechanisms of appearance of such structure are analysed, and the correlations between the fine structure parameters and actinide oxidation states and local environment, the magnetic properties of compounds, the nature of the chemical bond and secondary electronic processes that accompany photoemission of electrons are discussed. Experimental evidence for effective formation of the outer (Eb = 0–15 eV) and inner valence (Eb = 15–50 eV) molecular orbitals, in particular, from the fully occupied An6p and Lns orbitals of the neighbouring actinide (An) and ligand (L) atoms in the compounds in question is presented. The use of fine spectral structure parameters, together with the electron binding energies and line intensities extends significantly the scope of application of the XPS method in structural studies. The bibliography includes 276 references.

Retaining structure of homogeneous fluid and granular stream is one of the main criteria for technological process assuring the high quality outcome in many industries, including mechanical engineering and oil & gas industry. For example, in oil and gas industry during the pipeline transportation of oils there is a strong trend for cluster aggregation, and particle coarsening and entanglement. Dehomogenization of particle stream results in reverse dynamics of the stream. The importance of prevention and minimization of small particles coalescence by separating the oil stream leads to the need of improving the properties of the dispersers to boost their efficiency. Our paper investigates the operating principle of the disperser for separating particles (separator), which is designed by the authors. We have considered a particle stream of dispersed structure. We have obtained the conformity with the stability of the disperser operation. To yield the results we use the extremum problems for differential equations. This approach provides strong evidence that there are optimum parameters of the dispersers, which result in better stability of the particle stream.

The X-iay photoelectron spectroscopy (XPS) ionic and quantitative analysis of the reactor fuel containing masses (FCM) doped with the Cs, Sr ions before and after the up to 2300°C heating, as well as the “hot” particles formed during the laboratory simulated nuclear power plant accident under various conditions, was carried out. The U and Cs were shown to sublime within the first 20 seconds of the heating. Within the next 60 seconds the sublimation of U, Cs and Sr. was shown to take place. The “hot” particles collected within the first 20 seconds of heating and extra heated to 900°C in the air flow were shown to contain 68% of U and 32% of Cs, while the particle collected within the next 360 seconds and extra heated - 51% of U, 13% of Cs, and 36% of Sr. The “hot” particles were suggested to include the uranyl compounds like UO2CO3, Cs2UO4, Cs4UO2(CO3)3, CsUO2(OH)3, SrUO4, Sr3UO6, SrUO2CO3(OH)2. The Ar+treatment of the “hot” particles results in the change of their compositions.

In the present work it was found that the relative intensity of the quasiatomic An5f- electron line correlates with the number n5fof such electrons in actinide compounds. The experimental dependence of the relative An5f line intensity for Th, U, Np, Pu, Am, Cm, and Bk in various compounds on the number n5f(I5f= 0.02 n5f) in the range from 0 to 7 was obtained. It gave a unique opportunity to determine the oxidation state of actinides in compounds, to conduct the X-ray photoelectron quantitative ionic analysis on the basis of the An5f line intensity, to study the participation degree of electrons in the chemical binding, and to carry out the comparison with the results of the theoretical calculations of the photoemission cross-sections.

The role of the U6p,5f electrons in the chemical bond in γ-UO3was studied on the basis of the low-energy X-ray photoelectron, conversion electron spectra from uranium trioxide, and the calculations for the [UO2O4]6−(D4h) cluster.

The results of the X-ray photoelectron spectroscopy studies of the electronic structures of trifluorides, oxides and other compounds of Sc, Y and lanthanides (Ln) from La to Lu, except for Pm, in the binding energy range from 0 to 1350 eV are generalised. The established dependences of the Ln4f binding energies and the relative intensities of lines on the atomic number Z do not contradict the theoretical data stating that the Ln4f atomic orbitals (AO) participate markedly in the formation of molecular orbitals (MO) in the lanthanide compounds. It is established that inner valence molecular orbitals (IVMO) composed of the metal Sc3p, Y4p, Ln5p AO and the ligand L(O,F)2s AO are formed in these systems in addition to the outer valence molecular orbitals (OVMO). It is shown that the spectral fine structure caused by multiplet splitting, many-body perturbation and dynamic effects is correlated with the lanthanide oxidation state, the spin state of ions and the mechanisms of the secondary electronic processes accompanying the photoemission and can serve as a characteristic for identification of lanthanide compounds. Charge induction is discussed using titanium and niobium double oxides as examples. The bibliography includes 206 references.

The interaction of the uranyl group UO22+in aqueous solutions with hydroxylapatite and fluoroapatite was studied by X-ray photoelectron spectroscopy. The apatite samples under study were found to contain CO22+groups. The reaction of uranyl nitrate with hydroxylapatite in aqueous solutions does not lead to U(IV)-containing compounds but forms U(VI)-containing uranyl compounds with equatorial hydroxyl or carbonate groups partly replaced by fluorine in the uranyl compounds in the case of fluoroapatite. The interaction of the uranyl group with fluoroapatite in aqueous solutions is much more effective than the interaction with hydroxylapatite.

The fine structure of the X-ray photoelectron and O4,5(Th) X-ray emission spectra of the low-energy (0 …) ∼50eV) electrons of thorium in ThO2and ThF4is studied. It is established that both outer (0 … ∼15 eV) and inner (15… ∼50 eV) valence molecular orbitals, which are mostly due to the Th6p and O(F)2s shells of the neighboring thorium atoms and ligands, are formed in these compounds.

This paper presents an automated framework for the operational planning ofWiMax networks. The framework consists of a cell planning (network design) algorithm that selects and fully configures base station sites, together with an automatic frequency planning algorithm for assigning subchannels in an OFDMA scheme. Results are presented, which indicate that it is preferable to include the frequency planning directly in the cell planning process rather design the network and subsequently assign subchannels.

AbstractNeptunyl sorption in the ternary system of goethite–humic acid (HA)–Np was studied in a series of batch experiments with natural leonardite HA and a hydroquinone enriched derivative. The reduction of Np(V) at low pH has been observed by XPS upon interaction with hydroquinone-enriched leonardite HA–goethite suspension. Under these low pH conditions the formation of humate coatings at the goethite mineral surface has been identified using scanning transmission X-ray microscopy (STXM) at the carbon K-edge.

This paper proposes a method of sorting the information contained in video streams formed by sensors based on various physical principles. The method consists of estimating the degree of significance of local information from each sensor according to a definite information-content criterion, followed by blending of the discriminated most significant information into a single, combined image. The results of computer modeling showed that the proposed model has advantages over known methods in terms of response rate, comfort of presentation, and the absence of artifacts.

The objects of investigation were pyrochlore type Ln2Ti2O7 oxides (Ln = Sm—Lu) and ferroelectric La2Ti2O7 with layered perovskite-like structure. X-ray OKα TiKβ5, Kα1,2, Lα-emission spectra and X-ray photoelectron spectra of the valence and core states were obtained for pyrochlore oxides. For La2Ti2O7 X-ray photoelectron spectra have been measured. The cluster (Xα-Scattering Waves) and band structure calculations (LMTO-ASA) have been carried out to study valence band structure and the charge states of atoms. As a result the valence band (VB) parameters of the La2Ti2O7 series were defined. The Ln atomic number (ZLn) influence on the La2Ti2O7 (Ln = La; Sm-Lu) electronic structure was disclosed. The atomic charge states and their dependence on ZLn have been determined in mentioned oxides. The La2Ti2O7 electronic structure genesis has been defined

The x-ray photoelectron spectra of the core 2p1/2, 2p3/2, 3s1/2, 31/2 and 3p3/2 electrons of nickel in the oxide NiO and in an aluminum—nickel catalyst have been discussed on the basis of the results of a self-consistent calculation of the electronic states of the NiO610- cluster in the spin-polarized variation of the Xa—scattered-wave method with complete consideration of the relativistic properties of the core electrons in the angular-momentum-polarized variant. Partial consideration of the relativistic properties of the valence-band electons (consideration of the Darwin terms and the dependence of the mass on the velocity during the averaging of the wave functions and the density with respect to the angular momentum) does not alter the basic conclusions of the work.

Conclusions The general use of x-ray photoelectrona calculation methods enables one to go beyond the usual approximation in research on the electron structures of molecules and solids containing any elements, where the latter approximation is that the bonding is due in the main to the electrons in the unfilled valency subshells [23]. The interaction between the electrons in the internal filled subshells of adjacent atoms results in structures in the XPS due to electrons in the inner MO. Under certain conditions, this interaction may be so strong that it cannot be neglected. For example, in uranium compounds the difference in electron binding energies in the quasiatomic ?g MO of uranium and the ?u? MO due to U6p-O2s AO overlap varies with bond length in the uranyl group UO22+ from 2 to 5.5 eV [7, 8, 18]. Similarly, the differences in. electron binding energy for the internal 3?u- and 3?g+ MO in the S?2– clusters in the disulfides of 3d transition metals varies from 3 to 4 eV for different bond lengths [15].

A previously developed procedure for modeling the electronic structure of oxide systems, using a quantum-chemical calculation in the Xa-scattered wave approximation, has been applied to the investigation of cobaltous-cobaltic oxide Co3O4. As a model of octahedral and tetrahedral sublattices of the oxide we took CoO69- and CoO46-, respectively. An energy scheme has been constructed for Co3O4, and a quantitative interpretation has been given for the photoelectron and x-ray electronic spectra of the valence band, optical excitation spectra, and satellite shake-up lines.

The presence of Al atoms in tetrahedral and octahedral coordination in the crystal structure of γ-Al2O3 is responsible for the difference in potentials for these atoms close to the nucleus and, consequently, the difference in binding energy for the core electrons. In the x-ray photoelectron spectrum of γ-Al2O3, the line generated upon photoionization of the Al 2s shell has a complex shape (a maximum and a shoulder on the low-binding energy side). Its separation into two components shows that their relative intensity reflects the ratio of Al atoms of the oxide having respectively the coordination numbers 4 and 6. The difference in binding energy for Al 2s for the two types of atoms is 0.7 eV, which agrees with data on calculation of the charge in oxide clusters. On the basis of the calculation results for the Al atoms by the Hartree-Fock-Dirac-Slater method, it is shown that the effective electronic configuration of the atoms may also exert an effect on the binding energy of the core electrons.

The results of a quantum-chemical calculation of the electronic structure of the F2 molecule by the CNDO/2 and Xa-SW methods have been presented. The binding energies of the valence electrons calculated in accordance with Slater's transsition-state principle are in quantitative agreement with the experimental x-ray photoelectron data. The bonding character of the MO's has been evaluated on the basis of a calculation of the derivatives of the binding energy with respect to the internuclear distance and by determining the values of the orbital resonance energies, which characterize the covalent contribution of the electrons in different MO's to the chemical bonding in the molecule. It has been shown that the electrons in the inner valence 2sg MO make a significant contribution to the bonding of the atoms, which is only partially compensated by the antibonding properties of the 2su* inner valence MO. The predominant participation of the 2s AO's of the fluorine atoms in the formation of the 2sg and 2su* inner valence MO's has been established and is the reason for their significant stabilization and smaller energy splitting in comparison of other diatomic molecules, for example, N2. The specific feature of these MO's determine the clearly expressed bonding character of the 3sg MO, which is caused by the predominant interaction of the fluorine 2ps AO.

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Results of the total cross section differenceΔσLin anptransmission experiment at 1.19, 2.49 and 3.65 GeV incident neutron beam kinetic energies are presented. Measurements were performed at the Synchrophasotron of the Laboratory of High Energies of the Joint Institute for Nuclear Research in Dubna. Results were obtained with a polarized beam of free quasi-monochromatic neutrons passing through the new Dubna frozen spin proton target. The beam and target polarizations were oriented longitudinally. The present results were obtained at the highest energies of free polarized neutrons that can be reached at present. They extend the energy range of existing results from PSI, LAMPF and Saclay measured between 0.066 and 1.10 GeV. The new results are compared withΔσL(pn) data determined as a difference betweenΔσL(pd) andΔσL(pp) ANL-ZGS measurements. The values ofΔσLfor the isospin stateI=0 were deduced using knownppdata.

It is proved that the group of spinor norms of autometries of a generalized quadratic lattice ℒ over the ring of integral elements vpof a local field kp, in the case wherep∤2 and ℒ is a generalized translation, is generated by the spinor norms of symmetries contained in the group of autometries of ℒ. As a corollary, an extension to the case of generalized quadratic lattices is given for known sufficient conditions of coincidence of the genus and the spinor genus of a quadratic lattice. Bibliography: 9 titles.

Conclusions: The experiments showed that for solidification of α-containing high-level wastes, to increase the incorporation of plutonium and americium into the phosphate and borosilicate matrices, it is necessary to develop a technological regime for conducting the vitrification that would reduce substantially the residence time of the melt in the high-temperature region, that would ensure the presence of strong convection fluxes, which would not permit sedimentation of the heterogeneous phases formed in the melt (or the possibility of their periodic removal), in the melter and thereby would guarantee homogeneity of the melt of the compositions obtained throughout the entire technological process. Apparently, the most promising technological process, which largely meets the requirements listed, is vitrification of wastes in IPKhT-type melters (induction melter with a cold crucible), which is now being actively studied.

Abstract: The structure of the experimental conversion spectra of an ultrasoft nuclear isomer transition of uranium-235 in oxygen-containing uranium compounds is investigated quantitatively. The behavior of the intensity of the U6p1/2 line in the spectrum is analyzed. It is established that the quasiatomic U6p1/2 orbital in uranyl compounds retains (69±9)% primary electron density on the uranium atom, the remainder passing to molecular orbitals.

The fine structure of X-ray photoelectron spectra of uranium compounds in the range of electron binding energies from 0 to ∼50 eV is largely determined by the electrons of the outer and inner valence molecular orbitals arising from the valence atomic shells, including the U6p and Lns low-energy occupied atomic shells. This result is in agreement with the data of the electronic structure calculations of these compounds and confirmed by the nuclear electron (conversion) and X-ray emission spectroscopic investigations. It is shown that the fine structure of X-ray photoelectron spectra associated with the electrons of inner valence molecular orbitals makes it possible to judge the participation of the electrons of the occupied atomic shells in chemical bonding, the structure of the nearest environments of the atom, and the bond lengths in the compounds. The overall contribution of the electrons of these molecular orbitals to the absolute value of binding energy may prove to be comparable to the contribution of the electrons of the outer valence molecular orbitals to atomic bonding. This is a new and important fact in chemistry.