Electronic correlation effects and the Coulomb gap at finite temperature

We have investigated the effect of the long-range Coulomb interaction on the one-particle excitation spectrum of n-type Germanium, using tunneling spectroscopy on mechanically controllable break junctions. The tunnel conductance was measured as a function of energy and temperature. At low temperatures, the spectra reveal a minimum at zero bias voltage due to the Coulomb gap. In the temperature range above 1 K the Coulomb gap is filled by thermal excitations. This behavior is reflected in the temperature dependence of the variable-range hopping resitivity measured on the same samples: Up to a few degrees Kelvin the Efros-Shkovskii ln$R \propto T^{-1/2}$ law is obeyed, whereas at higher temperatures deviations from this law are observed, indicating a cross-over to Mott's ln$R \propto T^{-1/4}$ law. The mechanism of this cross-over is different from that considered previously in the literature.Comment: 3 pages, 3 figure

Interactions of lipid monolayers with the natural biopolymer hyaluronic acid

AbstractThe interaction of the natural mucopolysaccharide hyaluronic acid with different lipids, present in the natural membranes, was studied at the lipid/water interface using thermodynamic methods and X-ray diffraction. The results show that this biopolymer modifies the properties and the structure of the lipid monolayer. The two-dimensional crystalline lattice and domain structure of the charged octadecylamine monolayer are strongly disturbed by the hyaluronic acid, the monolayer compressibility increases and the monolayer collapse pressure drops down. In addition, the presence of charged lipid interfaces influences the structural organisation of the hyaluronic acid at the membrane/water interfaces. The impacts of these results on the structural organisation at the membrane interface are discussed

Towards LLOD-based language contact studies: a case study in interoperability

We describe a methodological and technical framework for conducting qualitative and quantitative studies of linguistic research questions over diverse and heterogeneous data sources such as corpora and elicitations. We demonstrate how LLOD formalisms can be employed to develop extraction pipelines for features and linguistic examples from corpora and collections of interlinear glossed text, and furthermore, how SPARQL UPDATE can be employed (1) to normalize diverse data against a reference data model (here, POWLA), (2) to harmonize annotation vocabularies by reference to terminology repositories (here, OLiA), (3) to extract examples from these normalized data structures regardless of their origin, and (4) to implement this extraction routine in a tool-independent manner for different languages with different annotation schemes. We demonstrate our approach for language contact studies for genetically unrelated, but neighboring languages from the Caucasus area, Eastern Armenian and Georgian

About low field memory and negative magnetization in semiconductors and polymers

Ginzburg-Landau bulk magnetization of itinerant electrons can provide a negative effective field in the Weiss model by coupling to localized magnetic moments. The coupling enforces remnant magnetization, which can be negative or positive depending on the sample magnetic history. Stable magnetic susceptibility of coupled nonequilibrium subsystems with magnetization reversal is always positive. Gauss-scale fields could be expected for switching between negative and positive remnant moments in semiconductors with coupling at ambient temperatures. Negative magnetization in ultra-high conducting polymers is also discussed within the developed framework.Comment: 8 pages, no figure

Вплив згодовування хелатних комплексів мікроелементів на середньодобовий баланс Cu, Zn та Мn в організмі корів у період роздою

The questions are considered about the effect of feeding of trace elements of different types and concentrations in premixes on the average daily balance of copper (Cu), zinc (Zn), manganese (Mn) in the organism of cows of Ukrainian black mottled dairy breed of the two months after calving. For the experiment, 40 cows were selected and formed four groups: one control and three experimental. The cows in the control group fed a premix of sulfate salts of copper, zinc and manganese in doses that are 100% covered their lack in a forage. Experimental animals from I, II and III groups were fed premixes with chelate complexes of Cu, Zn and Mn, which offset the deficiency of trace elements in the feed ration for 100, 50 and 25% (calculated on pure element), respectively. The diet was counted on a cow with an average live weight of 550 kg, with a daily milk yield of 20 kg 4% fat and balanced on the basis of the main nutrients in accordance with the norms. Іn the feeds, excrements, urine and milk of cows, the content of trace elements copper, zinc and manganese was determined by the standardized atomic absorption method on the spectrophotometer AAS-30 («SaglZeiss», Germany). Found a higher percentage of trace elements deposition in the body cows of feeding of chelates of copper, zinc, and manganese in the concentrations that cover their deficit in the diet in the 100% and 50% in the experimental I and II groups: Cu – 7.3% (P < 0.05) and 1.4%, Zn by 12.2% and 15.0% (P < 0.001), Mn by 13.2% (P < 0.01) and 9.0% (P < 0.05), respectively, in comparison with their sulfate salts in a 100 % dose. Based on the results of the balance study, the use in the feeding of cows during lactation of chelates of trace elements in concentrations intermediate to different experimental groups was proposed, namely – below normal their input in the form of sulfate salts on 25% for copper, 50% – zinc, and 65% – for manganese (calculated on pure element).Розглянуто питання щодо впливу згодовування мікроелементів різних типів і концентрацій у преміксах на середньодобовий баланс Купруму (Сu), Цинку (Zn), Мангану (Mn) в організмі корів української чорно-рябої молочної породи через два місяці після отелення. Встановлено вищий відсоток відкладання мікроелементів в організмі за згодовування коровам хелатів Cu, Zn і Mn у концентраціях, що покривають їхній дефіцит у раціоні на 100% та 50% в І і ІІ дослідних групах: Cu – на 7,3% (Р < 0,05) та 1,4%, для Zn – на 12,2% і 15,0% (Р < 0,001), Мn – на 13,2% (Р < 0,01) та 9,0% (Р < 0,05) відповідно, порівняно з їх сірчанокислими солями у 100 % дозі. На підставі результатів балансового досліду запропоновано використання в годівлі корів у період лактації хелатів мікроелементів у концентраціях, проміжних відносно різних дослідних груп, а саме – нижчих за норми їх введення у формі сірчанокислих солей на 25% для Cu, 50% – Zn, та 65% – для Мn (у розрахунку на чистий елемент)

Spinel Harzburgite-Derived Silicate Melts Forming Sulfide-Bearing Orthopyroxenite in the Lithosphere. Part 1: Partition Coefficients and Volatile Evolution Accompanying Fluid- and Redox-Induced Sulfide Formation

We report abundances of major trace and volatile elements in an orthopyroxenite vein cutting a sub-arc, mantle-derived, spinel harzburgite xenolith from Kamchatka. The orthopyroxenite contains abundant sulfides and is characterized by the presence of glass (formerly melt) both interstitially and as inclusions in minerals, comparable with similar veins from the West Bismarck arc. The glass formed by quenching of residual melts following crystallization of abundant orthopyroxene, amphibole, and minor olivine and spinel. The interstitial glass has a low-Ti, high-Mg# andesite composition, with a wide range of H2O and S contents but more limited F and Cl variations. We calculate trace element partition coefficients using mineral and glass data, including those for halogens in amphibole, which agree with experimental results from the literature. Despite having a similar, high-Mg# andesite composition, the orthopyroxene-hosted glass inclusions usually contain much more H2O and S than the interstitial glass (4–7 wt% and ∼2,600 ppm, respectively). The initial vein-forming melts were oxidized, recording oxygen fugacity conditions up to ∼1.5 log units above the fayalite–magnetite–quartz oxygen buffer. They intruded the sub-arc mantle lithosphere at ≥1,300°C, where they partially crystallized to form high-Mg# andesitic derivative melts at ca. 1,050–1,100°C. Comparison with literature data on glass-free orthopyroxenite veins from Kamchatka and the glass-bearing ones from West Bismarck reveals fundamental similarities indicating common parental melts, which were originally produced by low-degree melting (≤5%) of spinel harzburgite at ≥1,360°C and ≤1.5 GPa. This harzburgite source likely contained ≤0.05 wt% H2O and a few ppm of halogens. Volatile evolution inferred from glass compositions shows that (i) redox exchange between S6+ in the original melt and Fe2+ in the host mantle minerals, together with (ii) the formation of an S-bearing, (H2O, Cl)-rich hydrothermal fluid from the original melt, provides the conditions for the formation of abundant sulfides in the orthopyroxenites during cooling. During this process, up to 85% of the original melt S content (∼2,600 ppm) is locally precipitated as magmatic and hydrothermal sulfides. As such, melts derived from spinel harzburgite sources can concentrate chalcophile and highly siderophile metals in orthopyroxenite dykes and sills in the lithosphere

Localization length and impurity dielectric susceptibility in the critical regime of the metal-insulator transition in homogeneously doped p-type Ge

We have determined the localization length \xi and the impurity dielectric susceptibility \chi_{\rm imp} as a function of Ga acceptor concentrations (N) in nominally uncompensated ^{70}Ge:Ga just below the critical concentration (N_c) for the metal-insulator transition. Both \xi and \chi_{\rm imp} diverge at N_c according to the functions \xi\propto(1-N/N_c)^{-\nu} and \chi_{\rm imp}\propto(N_c/N-1)^{-\zeta}, respectively, with \nu=1.2\pm0.3 and \zeta=2.3\pm0.6 for 0.99N_c< N< N_c. Outside of this region (N<0.99N_c), the values of the exponents drop to \nu=0.33\pm0.03 and \zeta=0.62\pm0.05. The effect of the small amount of compensating dopants that are present in our nominally uncompensated samples, may be responsible for the change of the critical exponents at N\approx0.99N_c.Comment: RevTeX, 4 pages with 5 embedded figures, final version (minor changes