Sherds of the San Pedro pottery complex found in situ in association with new radiocarbon dates at the Real Alto site provide new insights into the origin of pottery technology in South America and cultural diversity during the Early Formative period on the coast of Ecuador.

Influence of backstreaming ions from the target on spot size of focused 2 MeV electron beam was considered. The 2D version of the particle-in-cell code KARAT was used to study the formation of the ions stream and dynamics of the electron beam. It was shown that light species emitted from the target can disrupt the beam. The emission of low-ionized states of tantalum cannot disrupt the beam during about 30 ns or longer. A few non-invasive techniques of mitigation of the beam disruption were considered. Final magnetic lens with fast variation of magnetic field of several hundred Ampere-turns per nanosecond is capable to stabilize initial spot size of the compressed beam at the target.

This study attempts to reconstruct food habits through carbon (C) and nitrogen (N) isotope analysis and C/N analysis of charred residues inside pottery from the Primorye in the Russian Far East (Luzanova Sopka 2, Sergeyevka 1, Boisman 2, and Vetka 2 sites). Dates were obtained that were from the later stages of the Rudnaya culture (6980–6485 BP, 7800–7400 cal BP), proto-Boisman type (6760–6330 BP, 7600–7300 cal BP), Boisman culture (6155–4720 BP, 7100–5400 cal BP), and Vetka culture (6030–5870 BP, 6900–6700 cal BP). There are major differences in the carbon and nitrogen isotope ratios between inland sites (δ13C –26.9 to –30.0‰, δ15N 7.6 to 9.3‰) and coastal sites (δ13C –18.1 to –24.2‰, δ15N 9.5 to 14.9‰). The results show that the diet of inland cultures consisted primarily of freshwater fish and terrestrial animals and plants, whereas that of coastal cultures consisted mainly of marine organisms.

One of the most intriguing questions of South American archaeology is the time, place, and origin of the earliest pottery. Since the late 1950s, the earliest pottery has been attributed to the materials of the Early Formative Valdivia culture (5600–3500 BP), coastal Ecuador. Excavations at the Real Alto site conducted in the 1970s and 1980s allowed the rejection of the spectacular “Jomon–Valdivia” hypothesis and established a local origin of the phenomenon. Recent radiocarbon dates from a joint Russian–Japanese–Ecuadorian project at Real Alto open a new page in our knowledge of the transition from pre-ceramic Las Vegas to ceramic Valdivia cultures.

Enormous progress is being made in developing observational facilities. As a result, there are new opportunities to observe structures at sub-mas resolution. To explore gravitationally lensed systems, we simulate radio-lobe images distorted by microlensing. We show that the positions of ‘holes’ in lensed images may indicate the positions of microlens groups or overdensities.

From 13-years of the spectral optical monitoring of a well-known broad-line radio galaxy 3C 390.3 we concluded that the geometry of the broad emission-line region is complex, while still the main part of the emission is coming from the accretion disk. Here we present part of the analysis of the broad Hα and Hβ emission lines, which are showing highly variable double-peaked profiles during the monitoring period (1995-2007), with the aim to probe the accretion disk properties. The disk-like geometry plays a dominant role, but the variability of Hα and Hβ line profiles and intensities shows a presence of an additional emission-line region, that has a different nature for different periods, e.g. in one period the observed variation can be well modeled if one assumes changes in position and size of the emitting disk along the accretion disk.

High-capacity conventional and advanced multicomponent metal hydride alloys were synthesized in this work by two different methods. A set of AB5–type intermetallic compounds, with different Al content, were produced by high-frequency vacuum induction melting method, while AB, A2B and mixed (AB5+Mg)-types composite nanocrystalline-amorphous alloys were obtained mechanochemically by high-energy ball milling in a planetary type mill. The alloys were characterized physically by XRD, SEM and thermodynamically by van't Hoff's plots derived from experimentally obtained PCT isotherms at various temperatures. Different optimized techniques for model electrode preparation from selected metal hydride alloys were also applied. The electrodes were charged-discharged electrochemically in concentrated alkaline solution. In this paper we compare the values for the electrochemical maximum capacity and cycle-life performance of the electrodes prepared by the investigated types of alloys.

Polymer/clay and polymer/nanodiamond composites were prepared via solution dispersion, melt processing and new so-called colloid-deposition techniques. The following polymers have been used as matrices: hydroxypropylcellulose, polysulfone and styrene-acrylonitrile copolymer. For estimation of particles distribution in polymer matrices the optical microscopy, SEM and TEM methods were used. The X-ray results demonstrate that at least at some compositions, the technique employed was successful to intercalate the clay structure. It was found that particles addition (at small concentration) to polymeric liquids leads to decrease of viscosity. Tensile testing showed considerable improvements of mechanical properties.

We consider a contribution of microlensing to the X-ray variability of high-redshifted QSOs. Cosmologically distributed gravitational microlenses could be localized in galaxies (or even in bulge or halo of gravitational macrolenses) or could be distributed in a uniform way. We have analyzed both cases of such distributions. We found that the optical depth for gravitational microlensing caused by cosmologically distributed deflectors could be significant and could reach $10^{-2} - 0.1$ at $z\sim 2$. This means that cosmologically distributed deflectors may contribute significantlly to the X-ray variability of high-redshifted QSOs ($z>2$). Considering that the upper limit of the optical depth ($\tau\sim 0.1$) corresponds to the case where dark matter forms cosmologically distributed deflectors, observations of the X-ray variations of unlensed QSOs can be used for the estimation of the dark matter fraction of microlenses.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

During the austral summer field season of the Russian Antarctic Expedition in 1999/2000, wide-angle reflections experiments were performed in the vicinity of the Russian station Vostok. A 60 MHz ice radar system with 12-bit digital recording was used. The measurements were taken along two perpendicular lines directed south–north and east–west with a distance of 200 m between marks. We used a one-layer model (without snow–firn zone influence) for the calculations. We calculate that the average velocity of radio-wave propagation in the ice sheet is168.4 ± 0.5 m μs−1.The same velocity was derived from hyperbolic diffractions from internal discontinuities. The results allow more accurate depth interpretation of radio-echo soundings.