Data on the sorption characteristics of synthetic X-ray amorphous calcium silicate obtained in the CaCl
2
–Na
2
SiO
3
–H
2
O model multicomponent system are presented. The isotherms of sorption of Sr
...2+
ions from aqueous solutions without supporting salt at Sr
2+
concentrations of 0.016 to 1.22 mmol/L at temperatures of 20, 40 and 60°C and the solid to liquid phase ratio S : L = 1 : 400 are presented. The maximum sorption capacities of synthetic X-ray amorphous calcium silicate and the recoveries of Sr
2+
ions were determined for various S : L ratios and for solutions containing no supporting salt and solutions mimicking the specific composition of fresh water. The Sr
2+
sorption kinetics at various temperatures was studied for the first time; and the activation energy of sorption was determined. The results can be used to develop practical recommendations for the production of this material and application in the processes of strontium sorption and immobilization.
The activity of microorganisms is a decisive factor in the transformation of the essential and, at the same time, toxic selenium (Se) in marine waters. This review provides an analysis of the ...literature data on the microbiological regulation of the state of Se in marine waters: the role of microorganisms in eliminating toxic Se from marine waters through precipitation of reduced Se forms and in the reverse process, transformation of Se into a form available to be taken up by organisms and involvement of this element in the biogeochemical cycle. The processes of transformation of the oxidized and reduced Se forms with the participation of microorganisms in marine waters are considered. It has been shown that in anaerobic conditions bacteria use the oxidized Se forms as electron acceptors (reduction). Bioavailable selenite and selenate ions are formed in the case of aerobic oxidation. Biotransformation of dissolved Se is a key mechanism for the formation of methylated gaseous Se forms in marine waters as one of the ways to remove this element from the aquatic environment.
A new and highly efficient way of obtaining finely dispersed LiCoPO
4
powder is developed with a given morphology from ammonium substituted precursor NH
4
CoPO
4
⋅H
2
O in a lithium nitrate melt. It ...is shown that the morphology of the obtained product is determined by the morphology of the used precursor and depends on the physicochemical conditions of its preparation. The obtained LiCoPO
4
and its precursors are characterized by means of XRD, SEM, and BET. Electrochemical tests show the resulting powder is electrochemically active. Cathode material based on the obtained LiCoPO
4
shows a high specific discharge capacity of 110 mA h/g at a current density corresponding to a charge/discharge rate of 1C, due to the high dispersion and lamellar morphology of the particles of the synthesized powder. The proposed procedure is characterized by the speed of obtaining the target product. It does not require the use of expensive equipment or additional stages of high-temperature crystallization and grinding, and can be scaled up to industrial use.
This paper is based on geological and geophysical data obtained during the 53th expedition of the R/V
Akademik Nikolaj Strakhov
. We analyze the structure of the Mid-Atlantic Ridge segment, 400 km ...long, in the North Atlantic (between 48° N and 51.5° N). According to our studies, this segment is characterized by specific structures formed during the formation of the oceanic crust with a reduced supply of basaltic melts. This factor leads to tectonic outcropping of deep and mantle rocks of the lower crust during the continuous extension in the rift valley. These processes, called “dry” spreading, were previously unknown in the North Atlantic.
The diagnostic complex of the Globus-M2 spherical tokamak (
R
= 36 cm,
a
= 24 cm), the only operating tokamak in Russia with a divertor plasma configuration, which operates in the range of ...subthermonuclear temperatures (
T
e
to 1.6 keV,
T
i
to 4.5 keV) and densities (
n
e
to 2 × 10
20
m
–3
), is described. The Globus‑M2 tokamak is the unique scientific facility, which is a part of the Federal Center for Collective Use of the Ioffe Institute, Russian Academy of Sciences “Materials Science and Diagnostics in Advanced Technologies.” This allows third parties to perform their research using it. The work contains a list of all diagnostics currently available on the tokamak. The description of the diagnostics is structured in such a way that the reader gets an idea of their capabilities for measuring plasma parameters with an emphasis on the limits and accuracy of the measured values, and also spatial and time resolution. At the same time, many technical details are omitted in order to save space; references are given to papers with a more detailed description of individual diagnostics.
The structure of King’s Trough and its surroundings (King’s mesostructural cluster), located on the eastern flank of the Mid-Atlantic Ridge in the North Atlantic, is described in this paper. This ...work is based on geological and geophysical data obtained during the 55th expedition of the R/V
Akademik Nikolaj Strakhov
. Six provinces were identified within the southeastern part of King’s Trough, based on the results of bathymetric survey. Each province has its own morphostructural feature resulting from multistage tectonic and volcanic processes, which alternate and conjugate with each other in time. According to seismoacoustic profiling data, three main types of seismic facies have been identified: (a) pelagic complexes; (b) deposits of turbidite flows; and (c) chaotic facies of gravity origin. It is shown that the anomalous magnetic field of the study area is the superposition of linear and isometric anomalies. The first were formed during the formation of the oceanic crust in the axial zone of spreading. The second are associated with volcanic massifs formed under intraplate conditions. The obtained data confirm the assumption that the formation of King’s Trough was preceded by the formation of an elongated arched rise, which became a scene of intense intraplate volcanism that increased from southeast to northwest. This stage was followed by subsidence of the axial part of the rise with the formation of King’s Trough and the Peake and Freen Troughs.
An extreme radiation of hundreds of species of different groups of animals occurred in Lake Baikal, Siberia, Russia; among them, amphipods represent one of the most remarkable groups of invertebrates ...with about 350 endemic species. Amphipods host associated epibiont rotifers, and the aim of the study is to explore the possibility that bdelloid rotifers living as epibionts on amphipods in Lake Baikal coevolved with their hosts and diversified with species-specific host-epibiont associations. We sampled 148 individual amphipods belonging to 16 species and isolated all epibiont bdelloids from them, discovering that only one bdelloid species, Embata parasitica, lives associated with at least six amphipod species belonging to three different families. Similar to what is known in most other bdelloid species, the morphospecies Embata parasitica from Lake Baikal is likely to be a complex of cryptic species, as suggested by the high genetic diversity we found in one mitochondrial marker sequenced from several animals. Yet none of the divergent genetic lineages seemed to be associated to only one or a few amphipod species. In addition, nine bdelloid species were found living in the lake, increasing the known diversity of the area to 12 bdelloid species.
Geological and geophysical data collected during the 53rd cruise of the R/V
Akademik Sergey Vavilov
are presented. It is shown that the lateral distribution of the Icelandic plume material to the ...south is not bounded by the Bight transform fault and continues further to the south. The Bight FZ affects the processes of crustal accretion and the formation of tectonic structures only in a spreading segment directly adjoining the Bight FZ from the south, i.e., the most distant from the Icelandic plume. The anomalous magnetic field studied made it possible to determine the half-spreading rate (11.7 mm/yr) in the westerly direction for the area between the Bight transform fault and the Modred nontransform fault of up to 3.6 Ma in age. It is shown that the flanks of the Mid-Atlantic Ridge represented a shallow-water area with some areas of land in the recent past.
Among the more than 340 species of symbiotic copepods associated with numerous scleractinian species, four have been reported from galls or cysts in three species of corals (Dojiri 1988; Kim and ...Yamashiro 2007). The relationship between these copepods and their scleractinian hosts remains poorly studied. The first report of a tubular corallite shape caused by copepods is presented.
The geological structure of a large volcanic edifice in the eastern flank of the large Charlie Gibbs Fracture Zone in the region of the Eastern Thule submarine rise (North Atlantic) is discussed. It ...is shown that the volcanic edifice was formed near the axial zone of the Mid-Atlantic Ridge in the interval of 64–67 Ma ago. Subsequently, its summit part was destroyed by wave abrasion, and then it sank along with the oceanic part of the plate to 2500 m deep. It was concluded that volcanism in the Rockall Rift Basin affected the region further to the south, which was already an oceanic basin and was separated from the rift basin with the Charlie Gibbs Fracture Zone.
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