Volatile components in diamonds, associated garnet (pyrope), and olivine from two extremely rare xenoliths of diamondiferous peridotites recovered from the Udachnaya kimberlite pipe in Yakutia, Russia, were analyzed by gas chromatography–mass spectrometry (GC–MS) using a Focus DSQ II Series Single Quadrupole GC–MS (Thermo Scientific, USA). These xenoliths are pyrope lherzolite and pyrope dunite based upon compositions of coexisting minerals. Unlike the pyrope lherzolite, which contained pyrope with moderate calcium (Ca)-component content (about 15 mol%), the dunite contained subcalcic chromium (Cr)-pyrope with low Ca-component content (less than 10 mol%). All investigated minerals contained dominating hydrocarbons and their derivatives represented by aliphatic (paraffins, olefins), cyclic (naphthenes, arenes), oxygenated (alcohols, ethers), and heterocyclic (dioxanes, furans) hydrocarbons;nitrogenated, chlorinated, and sulfonated compounds;carbon dioxide (CO2);and water (H2O). The relative concentration (rel%) of total hydrocarbon was 79.7 rel% for diamonds, 69.1 rel% for garnet, and 92.6 rel% for olivine, with a general amount of components ranging from 161 to 206. New data on volatiles in diamonds, associated garnet, and olivine suggest the presence of a wide spectrum of hydrocarbons along with nitrogen (N2), CO2, and H2O in some upper mantle areas.
Nikolay V. SobolevAnatoly A. TomilenkoTaras A. Bul’bakAlla M. Logvinova
1 Introduction The vertical stratification of the water column has a significant impact on the spatial distribution of aquatic organisms,the dynamics and structure of the food web
A striking feature of the Mongolian plateau is the wide range of air temperatures during a year,-30 to 30°C.High summer temperatures,atmospheric weathering and the arid climate lead to formation of numerous alkaline soda lakes that are covered by ice during 6–7 months per year.During the study period,the lakes had p H values between 8.1 to 10.4 and salinity between 1.8 and 360 g/L.According to chemical composition,the lakes belong to sodium carbonate,sodium chloride-carbonate and sodium sulfate-carbonate types.This paper presents the data on the water chemical composition,results of the determination of the rates of microbial processes in microbial mats and sediments in the lakes studied,and the results of a Principal Component Analysis of environmental variables and microbial activity data.Temperature was the most important factor that influenced both chemical composition and microbial activity.p H and salinity are also important factors for the microbial processes.Dark CO 2 fixation is impacted mostly by salinity and the chemical composition of the lake water.Total photosynthesis and sulfate-reduction are impacted mostly by p H.Photosynthesis is the dominant process of primary production,but the highest rate(386 mg C/(L?d)) determined in the lakes studied were 2–3 times lower than in microbial mats of lakes located in tropical zones.This can be explained by the relatively short warm period that lasts only 3–4 months per year.The highest measured rate of dark CO 2 assimilation(59.8 mg C/(L?d)) was much lower than photosynthesis.The highest rate of sulfate reduction was 60 mg S/(L?d),while that of methanogenesis was 75.6 μLСН 4 /(L?d) in the alkaline lakes of Mongolian plateau.The rate of organic matter consumption during sulfate reduction was 3–4 orders of magnitude higher than that associated with methanogenesis.
We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e+e-collider.We measure the branching fraction of radiative decay J/ψ→ηcγ,ηc width and mass.Our preliminary results are:M(ηc)=2979.4±1.5±1.9 MeV/c2,Γ(ηc)=27.8±5.1±3.3 MeV,B(J/ψ→ηcγ)=(2.34±0.15±0.40)%.
This paper outlines the results of experimental study of the dynamic rock failure based on the comparison of dry and saturated limestone samples obtained during the dynamic compression and split tests. The tests were performed using the Kolsky method and its modifications for dynamic splitting. The mechanical data(e.g. strength, time and energy characteristics) of this material at high strain rates are obtained. It is shown that these characteristics are sensitive to the strain rate. A unified interpretation of these rate effects, based on the structuraletemporal approach, is hereby presented. It is demonstrated that the temporal dependence of the dynamic compressive and split tensile strengths of dry and saturated limestone samples can be predicted by the incubation time criterion. Previously discovered possibilities to optimize(minimize) the energy input for the failure process is discussed in connection with industrial rock failure processes. It is shown that the optimal energy input value associated with critical load, which is required to initialize failure in the rock media, strongly depends on the incubation time and the impact duration. The optimal load shapes, which minimize the momentum for a single failure impact, are demonstrated. Through this investigation, a possible approach to reduce the specific energy required for rock cutting by means of high-frequency vibrations is also discussed.
Yuri V. PetrovIvan V. SmirnovGrigory A. VolkovAndrei K. AbramianAnatoliy M. BragovStanislav N. Verichev
The article deals with the actual social and philosophical problems connected with the value transformations of post-Soviet society in the transition period of its development.The focus is on mental(ideological)attitudes or“traps for practical reason”that prevent the democratization and humanization of Russian public consciousness.One of such mental attitudes is the trap of historical heritage,which is a complex of probabilistic judgments about the historical purpose of society and the complete determination of the future by its past.In the course of rational-critical analysis,the erroneous biogenetic approach to Russian history is revealed,as well as possible negative consequences of its application to the solution of urgent social problems.The historical situation of the“Blockade of Leningrad”is considered to be such a pressing problem.
The properties of Ni-doped strontium titanate are studied using X-ray diffraction and XAFS spectroscopy.It is shown that regardless of the preparation conditions,the SrTi_(1-x)Ni_(x)O_(3) solid solution and the NiTiO_(3) phase are the most stable phases which can coexist.According to the EXAFS data,in the single-phase sample of SrTi_(0.97)Ni_(0.03)O_(3),the Ni atoms substitute for the Ti ones and are oncenter.The distortion of the oxygen octahedra is not observed.The XANES spectra analysis shows that the oxidation state of nickel in NiTiO_(3) is 2+,and in the SrTi_(1-x)Ni_(x)O_(3) solid solution it is close to 4+.It is shown that the strongest light absorption in doped samples is associated with the presence of tetravalent nickel in the SrTi_(1-x)Ni_(x)O_(3) solid solution.This doping seems the most promising one for solar energy converters that exploit the bulk photovoltaic effect.
