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In this paper, we studied the process of hydrolysis of magnesium hydride with water vapor and considered the possibility of creating a chemical source of hydrogen based on this process. To study the hydrolysis reaction of magnesium hydride powder at temperatures above 100 °C, an experimental setup with a quartz tube — a reactor 300 mm long — was designed. The mass and volume of a single powder load in a quartz reactor was 65 g and 130 ± 2 cm3, respectively. The length of the powder zone along the axis of the reactor was approximately 10 cm. Based on the data obtained during the experiment, it can be distinguished that the length of the reaction zone is greatest at the beginning and at the end of the hydrolysis process and is approximately 5–6 cm. In the middle of the hydrolysis process, for the time interval from 3000 to 5000 s, the reaction zone is the smallest - about 4–5 cm. The proposed design of the hydrolysis reactor and the experimental setup also made it possible to study the peculiarities of the hydrolysis of magnesium hydride powder with water vapor; magnesium, the composition of the reaction products and the controllability of the generation of a stream of hydrogen.

The kinetics of dicyclopentadiene polymerization in toluene solution under the action of different catalytic systems through adiabatic thermometry was investigated. Unlike cationic metathesis polymerization has a sufficiently large induction period associated with low speed by implantation monomer on carbine bond of catalyst. It has been shown that the rate of metathesis polymerization of dicyclopentadiene in comparable circumstances is about three times lower than the rate of cationic polymerization of the same monomer.

A new experimental method for the determination of the isotopic composition of authigenic uranium in Lake Baikal (Siberia) sediments has supplied a record of (234U/238U)aut ratios during the past 150 ka with a resolution of ca. 200 years. Reconstruction of the (234U/238U)aut activity ratio as a proxy for lake water composition shows that the uranium isotope disequilibrium has not stayed constant throughout this period: it varied greatly in response to regional climate. The 234U/238U activity ratio in Lake Baikal paleowaters was inferred to be high during interglacial time (∼ 1.85–2 during MIS 5.5 and the Holocene; ∼ 1.4–1.7 during MIS 5.1 and 5.3) and dropped to ∼ 1.16 ± 0.01 during glacial time. The variability in the deduced 234U/238U ratios of Lake Baikal waters of the past may have been caused by the climatically-modulated redistribution of contributions of riverine discharges from different provinces of the very large catchment of the lake. Aridity during ice ages was more pronounced in the south of eastern Siberia and in northern Mongolia relative to that in the northern regions of the Lake Baikal watershed. The southern contribution of riverine input into the lake was essentially absent during glacial periods. Records of some elements (Ca/K, Sr/Rb, Si/Al, La/Th, U/Th, CIW) from the bottom sediments of Lake Baikal during the last 0.5 Myr with a resolution of ∼ 2 kyr have also been obtained. Coupling these data with records of weathering indices shows that not only riverine waters but also terrigenous material delivered into Lake Baikal from different regions of the very large watershed during interglacial and glacial times. Glacial erosion delivered fine siliciclastic material (“glacial milk”) mainly from the nearest mountain glaciers situated in the northwestern region of Lake Baikal while during warmer periods terrigenous material was sourced from the surrounding river valleys. A conceptual model for the simulation of the fluvial discharge gradient between the northern and southern provinces of the Lake Baikal watershed is proposed and a first-order simulation of past changes in the contribution of the Selenga River to the lake water budget is given.

A study of 15 gravity cores reveals consistent patterns of lithologic change throughout the Lake Hovsgol basin. Sediments of the last glacial are composed of calcareous clayey silt with an admixture of coarse material from sand to gravel. During the last deglaciation, a basin-wide deposition of finely laminated carbonate mud took place and was ultimately succeeded by the deposition of diatomaceous clayey ooze during the entire Holocene interval. Diatom productivity in Lake Hovsgol during the early Holocene was higher than today, but declined by ca. 6.6 cal ka BP. Sedimentation rate estimates for post-glacial section range from 1.5 to over 6.7 cm/ka for different parts of Lake Hovsgol. Rates appear to have decreased in the late Holocene. The last glacial maximum (LGM) corresponded to a dramatic low stand of Lake Hovsgol on the order of 100 m below today's level, as reflected by littoral facies retrieved in cores from intermediate depths. Age dating of plant fragments in these sediments suggests that lake level started rising no later than 15.4 cal ka BP. By the beginning of the Holocene, Lake Hovsgol evolved from a low-level closed basin lake to an overflowing freshwater lake. The observed dramatic lithologic change and evidence for lake-level change suggest that Lake Hovsgol may in fact serve as a sensitive ‘water gauge’ in continental interior Asia and that the Hovsgol sedimentary record preserves reliable proxies for past changes in effective moisture balance in the Lake Baikal catchment area.

Sedimentary sections from Lake Baikal in Siberia and Lake Hovsgol in Mongolia show that during the Last Glacial Maximum (LGM), planktonic/benthic diatoms, chrysophyte cysts, sponge spicules and zooplankton remains did not accumulate in the lake sediments. The combined data suggest a drastic lowering of photosynthetic production and perhaps the collapse of the ecosystems of both lakes due to significant environmental changes during the LGM. Both lakes were almost uninhabited during the LGM. Starting from ∼12,000 to 13,000 14C years ago, the planktonic communities redeveloped and primary production increased in both lakes. As a result, Holocene sediments contain abundant and well-preserved planktonic/benthic diatoms, stomatocysts, sponge spicules and zooplankton remains. The ecosystem stress in Lake Baikal during glacial time appears to be due to a decrease in nutrient loading from the watershed, lowering of surface water temperature, and very low transparency of water and ice. We believe that endemic species in Baikal survived during glacial ecological catastrophes in refugia that could have been a source of species that invaded and repopulated Baikal after intense and long glacial winters. The ecosystem stress in Lake Hovsgol during glacial time appears to be due primarily to drastic lake level falls, and changes in water chemistry. At the beginning of the Holocene, Lake Hovsgol was reoccupied again by cosmopolitan species probably from surrounding small lakes and rivers. In addition to the LGM results, we also show that Lake Baikal planktonic diatom species diversity during the last 350 ka is closely related to solar insolation fluctuations caused by the 23 and 41 ka cycles of the Earth's precession and obliquity. Our results also indicate that Baikal's planktonic diatom species diversity, as measured by the Shannon–Weiner index, correlates with the oxygen isotope record that represents changes in global ice volume.

By correlating the pronounced interstadial-type diatom peak with MIS 3, the high-resolution and well-dated record BDP-93-2 from the Selenga Delta area of Lake Baikal complements the classical long paleoclimatic records from Academician Ridge, which lack the pronounced MIS 3 warm signal. This correlation helps to resolve the age model controversies related to this interstadial interval. The content and C/N ratios of total organic carbon, as well as its stable isotope composition and diatom abundance, reveal high-frequency oscillatory variations reflecting the more unstable conditions of MIS 3 interstadial in the Lake Baikal region as compared with the Holocene interglacial. An important part of the regional climatic instability during the past 75,000 yrs BP revealed for the first time in the Baikal record is the recurrence of the abrupt erosional events leading to the deposition of the detrital carbonate material at the hemipelagic BDP-93 site. There were at least five such events: at MIS 5/4 transition, in the middle of MIS 4, and three during MIS 3. Stratigraphic and AMS-radiocarbon age models allow the Baikal erosional carbonate events to be confidently correlated to the intervals of Heinrich layers in the North Atlantic. This correlation suggests a surprisingly strong climatic teleconnection of the remote mid-continent Baikal location with the Dansgaard–Oeschger events and the bond cycles in the North Atlantic region.

A unique diatom biostratigraphy of the Brunhes chron in Lake Baikal revealed by detailed studies of pelagic diatom paleo-assemblages, indicates that dramatic changes in insolation during the past 800 ka BP produced surprisingly rapid diatom speciation and extinctions. The orbitally-tuned age model allows the diatom assemblages to be compared with individual marine isotopic stages and substages during the Brunhes. Most of the interglacial periods are characterized by explosive speciation and appearances of new pelagic planktonic diatom species. In contrast, most of the glacial periods are characterized by spectacular extinctions. Three broad periods characterized by different degrees of stability in the pelagic diatom assemblages are distinguished during the Brunhes chron in the Lake Baikal sedimentary record: MIS 19–15e, MIS 15a–11 and MIS 9–5. these periods are apparently associated with the long-term changes in the amplitude of precessional insolation variations. Examination of individual interglacial periods further reveals the sensitivity of the Baikal ecosystem to the regional energy balance: virtually every precessional insolation peak during the early Brunhes is characterized by a unique and peculiar paleo-assemblage. For the first time the siliceous microfossil record has demonstrated such a high degree of sensitivity to insolation forcing of regional climate. Despite the dramatic changes in the pelagic plankton driven by extreme climatic changes, diatoms never went fully extinct during any glacial period. Although greatly or completely renewed during each subsequent interglacial, the pelagic diatom assemblage still managed to return dominated by the new Baikal endemic species. The diatom assemblage observed in modern Lake Baikal, despite being mostly endemic, has formed during the past 50–100 ka and is therefore rather young. These results demonstrate the remarkable capacity of this large freshwater system to sustain the dynamic stability on the large time scales.

The new 600-m drill core BDP-98 from the Academician Ridge of Lake Baikal recovered a continuous sedimentary record of the past 10 Ma. The entire section is represented by lacustrine sediments, which gradually change from distal deltaic facies at the bottom of the section to fine undisturbed hemipelagic sediments of the upper 300-m interval. The entire 10-Ma lacustrine section contains abundant diatoms, thus allowing extension of Plio-Pleistocene diatom and biogenic silica records into the Miocene. Above the Matuyama/Gauss paleomagnetic reversal boundary, the BDP-98 record contains clearly delineated glacial/interglacial lithologic cycles. Below this boundary the diatom signal is quite different: average diatom contents are higher and variations are of lower amplitude. Although most likely paleoclimatic in origin, these variation presumably reflect past changes in the moisture regime of southeast Siberia under conditions of warm subtropical climate during the Miocene and Early–Middle Pliocene. The continuous BDP-98 drill core, which covers the hiati present in the composite continental sections of the Baikal region, is a key section for reconstructing the Neogene–Quaternary climatic evolution of continental Asia. The BDP-98 section also places several important time constraints on the rifting history of Lake Baikal by providing reliable correlation of lithological and physical properties of the drill core sediments with calculated positions of the acoustic reflection boundaries interpreted from multichannel seismic studies. The lithologic composition indicates that, on the stable block of Academician Ridge where the BDP-96 and BDP-98 drill sites are located, acoustic reflection boundaries are not associated with major erosional events, but instead result from changes in sediment density and composition. Several lithologic indices further suggest that significant changes have occurred in the physics and chemistry of Lake Baikal waters, affecting the carbonate equilibrium and oxygen regime of Baikal.

The records of diatom abundance, clay fraction content and magnetic susceptibility from Lake Baikal drill core BDP-96-1 reflect the climate-driven Plio-Pleistocene evolution of the Lake Baikal sedimentation system. In addition to the dramatic variations in the proxy records in response to the Northern Hemisphere ice ages, the Baikal record also indicates climatic deterioration from 2.8 to 2.5 Ma BP with evidence for an early Siberian glaciation around the Matuyama/Gauss paleomagnetic reversal boundary. The drill core data also allow correlation of this early glacial interval with the basin-wide seismic sequence boundary B10, which marks the unconformity produced by the active neotectonic phase in the Baikal rift zone. At the BDP-96 drill site, however, the strong B10 acoustic reflection was produced not by an erosional boundary, but instead by deposition of glacial clay layers. The paleomagnetic age scale of BDP-96-1 constrains the upper age of the Neobaikalian uplift/subsidence phase in the Baikal-Sayan region at ca. 2.5 Ma BP. The coincident timing of the paleoclimatic and tectonic events recorded in Lake Baikal sediments suggests a close causal link between regional tectonics and climate and indicate that the late Pliocene uplift contributed to the initiation of the early glaciation in southeast Siberia between 2.8 and 2.6 Ma BP by creating an elevated terrain with lower snowline, favorable for alpine glaciation, and by changing the heat balance of the region.