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Current climate change effects on the ground thermal regime in Central Yakutia

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Research in Cold and Arid Regions 2014年第4期6卷 282-292页

作者： Stepan Varlamov Yuri Skachkov Pavel Skryabin Melnikov Permafrost Institute Siberian Branch of the Russian Academy of Sciences

The evolution of ground thermal state has been studied to assess impacts of current climatic warming on permafrost in Central Yakutia. The analysis of long-term data of regional weather stations has revealed one of the highest increasing trends in mean annual air temperature in northern Russia. A forecast of surface air temperature fluctuations has been made by applying a frequency analysis method. Monitoring of ground thermal conditions allows us to identify inter-annual and long-term variability among a wide range of natural conditions. Experimental research has indicated a long-term dynamics of ground thermal state evolution： ground temperatures at the depth of zero annual amplitude and seasonally thawed layer depth. Long-term variability of thaw depth shows near-zero to weak positive trends in small valleys in contrast to weak negative trends on slopes. With significant climatic warming, the thermal state of near-surface layers of permafrost demonstrates steadiness. Anthropogenic impacts on ground thermal regime in various terrain types have been qualitatively evaluated. Clear-cutting, ground cover stripping, and post-fire deforestation in inter-alas type terrains result in a significant increase of temperature and seasonal ground thaw depth, as well as adverse cryogenic processes. The dynamics of mean annual ground temperature in slash and burn sites have been evaluated in reference to stages of successive vegetation recovery.

关键词： permafrost active layer climate ground temperature regime natural landscapes disturbed landscapes

Accounting for mineralogical composition and origin of soils and sedimentary rocks in thermal property predictions

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Research in Cold and Arid Regions 2014年第5期6卷 461-469页

作者： Rev I.Gavriliev Melnikov Permafrost Institute Siberian Branch of the Russian Academy of Sciences

A methodology for calculating the thermal conductivity of soils and rocks is developed which takes into account their origin and mineralogical *** method utilizes three *** is founded on the structural modeling of contact heat interaction between particles and fills and estimates the statistical probability distribution of the particles in the volume of the *** second approach analyses perturbation to the temperature field of the matrix medium by ellipsoidal *** third approach is to find the mean thermal conductivity of the solid skeleton in the universal model at different composition of rock-forming minerals.

关键词： soil sedimentary rock origin mineralogical composition thermal conductivity modeling

Stomatocysts of Chrysophytes in Lake Shira

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 68-69页

作者： Alena FIRSOVA Limnological Institute Siberian Branch Russian Academy of Sciences

The chrysophytes are distributed over all the *** a rule,these are planktonic,freshwater,cold-water *** are as well saltish-water chrysophytes species of genera Chrysococcus,Dinobryon,

关键词： Lake Shira chrysophycean stomatocysts phytoplankton sediments.

Lithospheric stress in Mongolia,from earthquake source data

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Geoscience Frontiers 2017年第6期8卷 1323-1337页

作者： Demberel Sodnomsambuu Anatoly V.Klyuchevskii Institute of Astronomy and Geophysics of Mongolian academy of Sciences UlaanbaatarMongolia Institute of the Earth Crust Russian Academy of SciencesSiberian BranchIrkutskRussia

Lithospheric stress in Mongolia has been studied using mechanisms of 84 M_(LH)≥ 4 earthquakes that occurred in the 20 th century and instrumental seismic moments of 17,375 M_(LH)≥2.5 events recorded between 1970 and *** M_(LH)≥ 3.5 earthquakes mostly have strike-slip mechanisms in southern and central Mongolia,with frequent reverse-slip motions in the west and normal slip in the north,especially,in the area of Lake *** principal stresses are,respectively,S_H>S_v>S_h in the center and in the south;high horizontal compression with S_H>S_h>S_v in the west;and a heterogeneous stress pattern with S_v>S_H>S_h in the *** to seismic moments of M_(LH)=2.5 events,oblique slip generally predominates over the territory,at S_v≈S_H>>S_h,while frequent strike slip motions in the west record high horizontal compression(S_H>S_v>S_h).Earthquake mechanisms show the principal horizontal compression S_H to be directed W-E in the east,NE-SW in the central and Gobi-Altay regions,and approximately N-S in the west of *** patterns of principal lithospheric stresses in the territory of Mongolia have undergone three events of dramatic change for a few recent decades,and these events were synchronous with three similar events in the Baikal rift system(BRS):in the latest 1960 s,latest 1970 s to earliest 1980 s,and in the latest 1980 s to earliest 1990 *** seismicity of Mongolia has been controlled by superposition of variable stresses associated with rifting activity pulses in the neighbor BRS on the background of quasi-stationary super-regional compression.

关键词： Lithospheric stress Mongolia Geodynamics Earthquake source data

Preparation and Properties of Foam Glass-ceramic from Diatomite

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Journal of Wuhan University of Technology(Materials Science) 2018年第2期33卷 273-277页

作者： Ivanov KS Institute of the Earth Cryosphere Siberian Branch of Russian Academy of Sciences Tyumen 625026 Russia Tyumen Industrial University Tyumen 625000 Russia

The results of the study of raw mix preparation and foam glass-ceramics production using diatomite as a raw material were presented in the following article. A mixture of diatomite and 40% NaOH solution was subjected to heating at a constant temperature of 775 ℃. Samples of foam glass-ceramic from diatomite with an average density of 290-580 kg/m^3, compressive strength of 1.7-7.8 MPa and thermal conductivity of 0.08-0.14 W/（m·K） were obtained. The investigations have shown that the hydrothermal pretreatment of mixture at the temperature of 90 ℃ may lead to the acceleration of the leaching of amorphous SiO_2 from diatomite. It was discovered that the resulting soluble alkali silicates promote the process of foaming during heating and reduce the average density of the obtained samples. The optimal duration of the leaching process was estimated to be 30 minutes, which corresponds to the yield of SiO_2 equal to 42.5% by the weight of dry diatomite.

关键词： diatomite liquid glass foam glass-ceramics

Effects of Substrate Pulse Bias Duty Cycle on the Microstructure and Mechanical Properties of Ti–Cu–N Films Deposited by Magnetic Field-Enhanced Arc Ion Plating

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Acta Metallurgica Sinica(English Letters) 2017年第2期30卷 176-184页

作者： Sheng-Sheng Zhao Yan-Hui Zhao Lv-Sha Cheng Vladimir Viktorovich Denisov Nikolay Nikolaevich Koval Bao-Hai Yu Hai-Juan Mei School of Mechanical and Electrical Engineering Shenzhen Polytechnic Institute of Metal Research Chinese Academy of Sciences Institute of High Current Electronics Siberian BranchRussian Academy of Sciences

Ti–Cu–N films were deposited on 316 L stainless steel substrates by magnetic field-enhanced arc ion *** effect of substrate pulse bias duty cycle on the chemical composition,microstructure,surface morphology,mechanical and tribological properties of the films was systemically *** results showed that,with increasing the duty cycle,Cu content decreases from 3.3 to 0.58 at.%.XRD results showed that only Ti N phase is observed for all the deposited films and the preferred orientation transformed from Ti N（200） to Ti N（111） plane with the increase in duty *** surface roughness and deposition rate showed monotonous decrease with increasing the duty *** residual stress and hardness firstly increase and then decrease afterwards with the increase in duty cycle,while the variation of critical load shows reverse *** for the film with duty cycle of 10%,others perform the better wear resistance.

关键词： Magnetic field Arc ion plating Ti-Cu-N film Residual stress Hardness

Numerical simulation of roof cavings in several Kuzbass mines using finite-difference continuum damage mechanics approach

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International Journal of Mining Science and Technology 2020年第2期30卷 157-166页

作者： Mikhail Eremin Gabriel Esterhuizen Igor Smolin Institute of Strength Physics and Materials Science Siberian BranchRussian Academy of SciencesTomsk 634055Russian Federation National Institute for Occupational Safety and Health PittsburghPA 15236USA National Research Tomsk State University Tomsk 634050Russian Federation

An essential stage of mine design is an estimation of the steps of the first and periodic roof caving in longwall ***,this is carried out using the field experience and can be much enhanced by numerical *** this work,the finite-difference method was applied coupled with the continuum damage mechanics(CDM)approach to simulate the stress-strain evolution of the rock mass with the underground opening during coal *** steps and stages of roof caving were estimated relying on the numerical simulation data,and they were compared with the field data from several operating mines in the south of the Kuznetsk Basin,*** dependence of the first roof caving step in simulation linearly correlates with field *** results correspond to the actual roofs of longwall panels of the flat-dipping coal seams and the average rate of face advancement is approximately 5 m/day.

关键词： Longwall mining Rock mass Underground openings Roof caving Abutment pressure Numerical simulation

Effect of local environment in resonant domains of polydisperse plasmonic nanoparticle aggregates on optodynamic processes in pulsed laser fields

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Chinese Physics B 2015年第4期24卷 467-474页

作者： A.E.Ershov A.P.Gavrilyuk S.V.Karpov P.N.Semina L.V.Kirensky Institute of Physics Russian Academy of Sciences Institute of Computational Modeling Russian Academy of Sciences siberian State Aerospace University siberian Federal University

Interactions of pulsed laser radiation with resonance domains of multiparticle colloidal aggregates having an increasingly complex local environment are studied via an optodynamic model. The model is applied to the simplest configurations, such as single particles, dimers, and trimers consisting of mono- and polydisperse Ag nanoparticles. We analyze how the local environment and the associated local feld enhancement by surrounding particles affect the optodynamic processes in domains, including their photomodification and optical properties.

关键词： nanoparticle surface plasmon colloid aggregate optodynarnics

Simulation of hydrocarbons pyrolysis in a fast-mixing reactor

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Chinese Journal of Chemical Engineering 2015年第6期23卷 941-953页

作者： M.G.Ktalkherman I.G.Namyatov Khristianovich Institute of Theoretical and Applied Mechanics Russian Academy of ScienceSiberian Branch Voevodsky Institute of Chemical Kinetics and Combustion Russian Academy of ScienceSiberian Branch

Currently, thermal decomposition of hydrocarbons for the production of basic petrochemicals(ethylene, propylene) is carried out in steam-cracking processes. Aside from the conventional method, under consideration are alternative ways purposed for process intensification. In the context of these activities, the method of hightemperature pyrolysis of hydrocarbons in a heat-carrier flow is studied, which differs from previous ones and is based on the ability of an ultra-short time of feedstock/heat-carrier mixing. This enables to study the pyrolysis process at high temperature(up to 1500 K) at the reactor inlet. A set of model experiments is conducted on the lab scale facility. Liquefied petroleum gas(LPG) and naphtha are used as a feedstock. The detailed data are obtained on temperature and product distributions within a wide range of the residence time. A theoretical model based on the detailed kinetics of the process is developed, too. The effect of governing parameters on the pyrolysis process is analyzed by the results of the simulation and experiments. In particular, the optimal temperature is detected which corresponds to the maximum ethylene yield. Product yields in our experiments are compared with the similar ones in the conventional pyrolysis method. In both cases(LPG and naphtha), ethylene selectivity in the fast-mixing reactor is substantially higher than in current technology.

关键词： Liquefied petroleum gas Pyrolysis Olefins Fast-mixing reactor