Ferro-electric phase transition in a polar liquid and the nature of \lambda-transition in supercooled water

We develop a series of approximations to calculate free energy of a polar liquid. We show that long range nature of dipole interactions between the molecules leads to para-electric state instability at low temperatures and to a second-order phase transition. We establish the transition temperature, T_{c}, both within mean field and ring diagrams approximation and show that the ferro-electric transition may play an important role explaining a number of peculiar properties of supercooled water, such as weak singularity of dielectric constant as well as to a large extent anomalous density behavior. Finally we discuss the role of fluctuations, shorter range forces and establish connections with phenomenological models of polar liquids.Comment: 5 pages, 1 eps figure, density anomaly at T=4C analysis adde

Sharpness of the phase transition and exponential decay of the subcritical cluster size for percolation on quasi-transitive graphs

We study homogeneous, independent percolation on general quasi-transitive graphs. We prove that in the disorder regime where all clusters are finite almost surely, in fact the expectation of the cluster size is finite. This extends a well-known theorem by Menshikov and Aizenman & Barsky to all quasi-transitive graphs. Moreover we deduce that in this disorder regime the cluster size distribution decays exponentially, extending a result of Aizenman & Newman. Our results apply to both edge and site percolation, as well as long range (edge) percolation. The proof is based on a modification of the Aizenman & Barsky method.Comment: Latex 2e; 25 pages (a4wide); small editorial corrections; one reference adde

Contact problems for cracks under impact loading

Peer reviewedPublisher PD

Magnetism in small bimetallic Mn-Co clusters

Effects of alloying on the electronic and magnetic properties of Mn$_{x}$Co$_{y}$ ($x+y$=$n$=2-5; $x$=0-$n$) and Mn$_2$Co$_{11}$ nanoalloy clusters are investigated using the density functional theory (DFT). Unlike the bulk alloy, the Co-rich clusters are found to be ferromagnetic and the magnetic moment increases with Mn-concentration, and is larger than the moment of pure Co$_n$ clusters of same size. For a particular sized cluster the magnetic moment increases by 2 $\mu_B$/Mn-substitution, which is found to be independent of the size and composition. All these results are in good agreement with recent Stern-Gerlach (SG) experiments [Phys. Rev. B {\bf 75}, 014401 (2007) and Phys. Rev. Lett. {\bf 98}, 113401 (2007)]. Likewise in bulk Mn$_x$Co$_{1-x}$ alloy, the local Co-moment decreases with increasing Mn-concentration.Comment: 11 pages, 15 figures. To appear in Physical Review

ОПРЕДЕЛЕНИЕ ЭЛЕМЕНТОВ ПЛАТИНОВОЙ ГРУППЫ В ГОРНЫХ ПОРОДАХ МЕТОДОМ ИСП-МС С ВНЕШНЕЙ ГРАДУИРОВКОЙ ПОСЛЕ ОТДЕЛЕНИЯ МАТРИЧНЫХ ЭЛЕМЕНТОВ НА КАТИОНИТЕ КУ-2-8

The analytical technique to determine platinum-group elements (PGEs) Ru, Rh, Pd, Ir, Pt and Re in the geological samples within 0.1 ng/g – 10 μg/g range and Os on ng/g level in the ultramafic  rocks by inductively coupled plasma mass-spectrometry with external calibration and without chemical removal of main interferences of Zr and Hf was proposed. The samples were prepared after their burning by acid decomposition in the open vessels, melting the insoluble residue with NH4F and with a subsequent cation exchange separation of PGEs from matrix elements by KU-2-8 resin (Russia). The measurements have been carried out using the high resolution mass-spectrometer Element 2 (Germany). The accuracy of the technique on μg/g level has been verified with reference materials: pyrrhotite ore RP-1 (Russia) and sulfide copper-nickel ore Zh-3 (Russia). In addition, the accuracy of the trace level (ng/g) has been verified by comparison of the results obtained in this study with those reported in the literature for international sample of comparison OPY-1, developed by the International Association of Geoanalysts (IAG). The procedural blanks are 0.000n ng/ml for Os, 0.00n ng/ml for Ru, Rh, Re, Ir and 0.0n ng/ml for Pt and Pd. The detection limits were estimated by taking into account the blanks and their standard deviations (sample mass 1 g, volume 50 ml) and were 0.02 ng/g for Os, 0.07 ng/g for Re, 0.09 ng/g for Rh and Ir, 0.13 ng/g for Ru, 1.0 ng/g for Pt and 1.4 ng/g for Pd respectively. The content of Re was determined in the reference materials RP-1 and Zh-3, and in the sample of comparison OPY-1.Key words: platinum-group elements and Re, inductively coupled plasma mass-spectrometry, chromatographic separation, RP-1, Zh-3, OPY-1, external calibration.(Russian) DOI: http://dx.doi.org/10.15826/analitika.2016.20.3.003V.I. Men’shikov, V.N. Vlasova, V.I. Lozhkin, Iu.V. Sokol’nikova Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences   (IGC SB RAS) Favorsky ul., 1A, Irkutsk, 664033, Russian FederationПредложена методика определения элементов платиновой группы (ЭПГ) Ru, Rh, Pd, Ir, Pt и Re в геологических образцах в диапазоне концентраций от 0.1 нг/г до 10 мкг/г, а также Os в перидотитах на уровне нг/г методом масс-спектрометрии с индуктивно связанной плазмой с внешней градуировкой и без химического удаления Zr и Hf. Подготовка проб основана на их кислотной деструкции в открытых системах после обжига с последующим доплавлением нерастворимого остатка с NH4F и отделением матричных элементов на катионите КУ-2-8 (фирма Токем, Россия). Измерения выполнены на масс-спектрометре высокого разрешения Element 2 (Finnigan MAT, Германия). Правильность определения содержания ЭПГ на уровне мкг/г подтверждена сравнением полученных результатов с аттестованными значениями для двух государственных стандартных образцов (ГСО) руды пирротиновой сплошной РП-1 и руды сульфидной медно-никелевой Ж-3, а для содержания аналитов на уровне нг/г – анализом международного образца сравнения перидотита OPY-1 (GeoPT-20), разрабатываемого Международной Ассоциацией Геоаналитиков (IAG). Значения пределов обнаружения, рассчитанные c учетом величины контрольного опыта и его стандартного отклонения (при переведении навески 1 г в 50 мл) составили: для Ru – 0.13 нг/г, Rh – 0.09 нг/г, Pd – 1.4 нг/г, Re – 0.07 нг/г, Os – 0.02 нг/г, Ir – 0.09 нг/г, Pt – 1.0 нг/г. Определены концентрации Re в ГСО РП-1, Ж-3 и OPY-1. Ключевые слова: элементы платиновой группы, рений, масс-спектрометрия с индуктивно связанной плазмой, хроматографическое разделение на катионите, ГСО РП-1, ГСО Ж-3, OPY-1.DOI: http://dx.doi.org/10.15826/analitika.2016.20.3.00

Influence of epithermal muonic molecule formation on kinetics of the μ\muCF processes in deuterium

The non-resonant formation of $dd\mu$ molecules in the loosely bound state in collisions of non-thermalized $d\mu$ atoms with deuterium molecules D$_2$ has been considered. The process of such a type is possible only for collision energies exceeded the ionization potential of D$_2$. The calculated rates of $dd\mu$ formation in the above-threshold energy region are about one order of magnitude higher than obtained earlier. The role of epithermal non-resonant $\mu$-molecule formation for the kinetics of $\mu$CF processes in D$_2$ gas was studied. It was shown that the non-resonant $dd\mu$ formation by $d\mu$ atoms accelerated during the cascade can be directly observed in the neutron time spectra at very short initial times.Comment: 6 pages, 5 figures, Proceedings of the International Conference on Exotic Atoms and Related Topics EXA-2011, Vienna, Sep 5-9, 201

Observer dependence for the phonon content of the sound field living on the effective curved space-time background of a Bose-Einstein condensate

We demonstrate that the ambiguity of the particle content for quantum fields in a generally curved space-time can be experimentally investigated in an ultracold gas of atoms forming a Bose-Einstein condensate. We explicitly evaluate the response of a suitable condensed matter detector, an ``Atomic Quantum Dot,'' which can be tuned to measure time intervals associated to different effective acoustic space-times. It is found that the detector response related to laboratory, ``adiabatic,'' and de Sitter time intervals is finite in time and nonstationary, vanishing, and thermal, respectively.Comment: 9 pages, 2 figures; references updated, as published in Physical Review

The explanation of unexpected temperature dependence of the muon catalysis in solid deuterium

It is shown that due to the smallness of the inelastic cross-section of the $d\mu$-atoms scattering in the crystal lattice at sufficiently low temperatures the $dd\mu$-mesomolecules formation from the upper state of the hyperfine structure $d\mu (F=3/2)$ starts earlier than the mesoatoms thermolization. It explains an approximate constancy of the $dd\mu$-mesomolecule formation rate in solid deuterium.Comment: 6 pages, 2 jpeg-figure

Bound state spectra of three-body muonic molecular ions

The results of highly accurate calculations are presented for all twenty-two known bound $S(L = 0)-, P(L = 1)-, D(L = 2)-$ and $F(L = 3)-$states in the six three-body muonic molecular ions $pp\mu, pd\mu, pt\mu, dd\mu, dt\mu$ and $tt\mu$. A number of bound state properties of these muonic molecular ions have been determined numerically to high accuracy. The dependence of the total energies of these muonic molecules upon particle masses is considered. We also discuss the current status of muon-catalysis of nuclear fusion reactions.Comment: This is the final version. All `techical' troubles with the Latex-file have been resolved. A few misprints/mistakes in the text were correcte

Determination of platinum-group elements in rocks by ICP-MS with external calibration after cation exchange separation of matrix elements by KU-2-8 resin

The analytical technique to determine platinum-group elements (PGEs) Ru, Rh, Pd, Ir, Pt and Re in the geological samples within 0.1 ng/g – 10 μg/g range and Os on ng/g level in the ultramafic rocks by inductively coupled plasma mass-spectrometry with external calibration and without chemical removal of main interferences of Zr and Hf was proposed. The samples were prepared after their burning by acid decomposition in the open vessels, melting the insoluble residue with NH4 F and with a subsequent cation exchange separation of PGEs from matrix elements by KU-2-8 resin (Russia). The measurements have been carried out using the high resolution mass-spectrometer Element 2 (Germany). The accuracy of the technique on μg/g level has been verified with reference materials: pyrrhotite ore RP-1 (Russia) and sulfide copper-nickel ore Zh-3 (Russia). In addition, the accuracy of the trace level (ng/g) has been verified by comparison of the results obtained in this study with those reported in the literature for international sample of comparison OPY-1, developed by the International Association of Geoanalysts (IAG). The procedural blanks are 0.000n ng/ml for Os, 0.00n ng/ml for Ru, Rh, Re, Ir and 0.0n ng/ml for Pt and Pd. The detection limits were estimated by taking into account the blanks and their standard deviations (sample mass 1 g, volume 50 ml) and were 0.02 ng/g for Os, 0.07 ng/g for Re, 0.09 ng/g for Rh and Ir, 0.13 ng/g for Ru, 1.0 ng/g for Pt and 1.4 ng/g for Pd respectively. The content of Re was determined in the reference materials RP-1 and Zh-3, and in the sample of comparison OPY-1.Предложена методика определения элементов платиновой группы (ЭПГ) Ru, Rh, Pd, Ir, Pt и Re в геологических образцах в диапазоне концентраций от 0.1 нг/г до 10 мкг/г, а также Os в перидотитах на уровне нг/г методом масс-спектрометрии с индуктивно связанной плазмой с внешней градуировкой и без химического удаления Zr и Hf. Подготовка проб основана на их кислотной деструкции в открытых системах после обжига с последующим доплавлением нерастворимого остатка с NH4F и отделением матричных элементов на катионите КУ-2-8 (фирма Токем, Россия). Измерения выполнены на масс-спектрометре высокого разрешения Element 2 (Finnigan MAT, Германия). Правильность определения содержания ЭПГ на уровне мкг/г подтверждена сравнением полученных результатов с аттестованными значениями для двух государственных стандартных образцов (ГСО) руды пирротиновой сплошной РП-1 и руды сульфидной медно-никелевой Ж-3, а для содержания аналитов на уровне нг/г – анализом международного образца сравнения перидотита OPY-1 (GeoPT-20), разрабатываемого Международной Ассоциацией Геоаналитиков (IAG). Значения пределов обнаружения, рассчитанные c учетом величины контрольного опыта и его стандартного отклонения (при переведении навески 1 г в 50 мл) составили: для Ru – 0.13 нг/г, Rh – 0.09 нг/г, Pd – 1.4 нг/г, Re – 0.07 нг/г, Os – 0.02 нг/г, Ir – 0.09 нг/г, Pt – 1.0 нг/г. Определены концентрации Re в ГСО РП-1, Ж-3 и OPY-1