Reconstruction of characteristics of sedimentary environments of the Lower Paleozoic Sandstone (hereafter LPS) sequence in the northwestern Russian platform based on granulometric and texture analyses reveals high pal...Reconstruction of characteristics of sedimentary environments of the Lower Paleozoic Sandstone (hereafter LPS) sequence in the northwestern Russian platform based on granulometric and texture analyses reveals high paleohydrodynamic conditions of sedimentation which decrease to moderate in south-east direction. Determination of quantitative paleolithodynamic parameters showed that the real sedimentation duration was considerably less than the related stratigraphic scale interval that is evidence of long interrupt of sedimentation and re-deposition of the clastic material. Study of paleolithodynamics is significant both for reconstruction of the paleobasin history and assessment of mineral resources.展开更多
The growth,survival,and mortality of conifer species in response to the hydrothermal regime have received considerable attention.It is expected that the highest sensitivity of trees to the warming-drying climate will ...The growth,survival,and mortality of conifer species in response to the hydrothermal regime have received considerable attention.It is expected that the highest sensitivity of trees to the warming-drying climate will occur mainly at the edges of the species ranges.We focused on the responses to climate change of the drought-resistant larch(Larix sibirica)and the moisture-sensitive Siberian pine(Pinus sibirica)along the elevation gradient in the Tannu-Ola Ridge,the southern margin where those two species coexist in Siberia by using satellite data(MODIS,Landsat,and microwave),the indexes of gross(GPP)and net(NPP)primary productivity,and tree radial growth index(GI).We found that since the warming restart in the 2000s,the area of larch-dominated forests increased by~150%while the area of pine-dominated forests decreased by~10%.The Siberian pine has retreated at low elevations(<1800 m)and increased its area at higher ones.In contrast,the area of larch stands increased in both the uphill and downhill directions.Birch(Betula spp.)also increased its area at low elevations(about+120%).Since 2001,the forested area increased by~5%.A shrubification,i.e.,an increase in the area of shrubs,was observed at high elevations.The uphill rate of timberline and shrubline migration was about 0.3 m/a.Since the 2000s,vegetation NPP has increased by 13%.A notable correlation between NPP and the GI of larch and pine was found(r=0.5-0.7).At lower elevations,NPP positively correlated with precipitation and soil moisture,while air temperature and VPD(vapor pressure deficit)increase inhibited productivity.At high elevations,the effects of these variables on productivity reversed.The continuous decline of the Siberian pine forest indicates an inevitable retreat of this species at low elevations and its replacement by larch and birch.展开更多
The phenomenon of mud volcanism has a connection with the processes of hydrocarbon generation.However,the genesis of sediments is not often taken into consideration.The study of mud volcanoes in the West Kuban margina...The phenomenon of mud volcanism has a connection with the processes of hydrocarbon generation.However,the genesis of sediments is not often taken into consideration.The study of mud volcanoes in the West Kuban marginal marine basin and the Junggar freshwater basin revealed significant isotope-geochemical differences due to various types of sedimentation.The waters from both basins exhibit three principal geochemical facies:Na-HCO_(3),Na-Cl-HCO_(3),and Na-Cl,of which the latter type of water is the dominant.The analysis of genetic coefficients(Cl/Br,Na/Br,and B/Cl)allowed us to distinguish different pathways of mud volcanic water evolution:evaporite dissolution,formation(sedimentation)waters,and waters formed by active water-rock interaction.Through statistical research,we were able to determine that noticeable variations in the behavior of chemical elements in waters from different areas can reflect discrepancies in the geological environment and the evolutionary stage of the diagenetic water transformation.Using thermodynamic modeling,the main directions of mass transfer were shown.It was established that the waters of the Junggar Basin were at a relatively early stage of evolution and had reached equilibrium only with carbonates,while in the formation waters of the West Kuban Basin,element concentrations were also controlled by silicate minerals.The correlations betweenδ^(18)O andδ~2H values and saturation indices of halides,aluminosilicates,sulfates,and borates confirm the enrichment of water with heavy isotopes during interactions with rocks without evaporation or thermal water partition.These reactions are characterized by clay dehydration and water enrichment with^(18)O and B.The data obtained made it possible to clarify the depths of formation of mud-volcanic fluids and their possible stratigraphic sources.展开更多
Radial growth of trees is highly sensitive to environmental changes,but the effect of climate on tree rings in Qinghai spruce(Picea crassifolia),a widely distributed endemic conifer in western China,is more complex th...Radial growth of trees is highly sensitive to environmental changes,but the effect of climate on tree rings in Qinghai spruce(Picea crassifolia),a widely distributed endemic conifer in western China,is more complex than in many other conifers.A comprehensive understanding of the spatiotemporal climatic responses of its rings is needed to develop theoretical basis for designing strategies for its conservation and management.Here,our synthesis of the literature on responses of radial growth of Qinghai spruce to monthly climate variables in different environmental conditions by meta-analysis showed that precipitation and drought severity are the main limiting factors for Qinghai spruce radial growth in the semiarid region of northwestern China.In warmer and drier areas,radial growth of Qinghai spruce is mainly limited by drought.In the areas north of the 600-mm annual precipitation isoline,the tree-ring width(TRW)was significantly positively correlated with precipitation and significantly negatively correlated with temperature during the growing season(June-August).The limiting effect of drought on Qinghai spruce is also gradually increasing from southeast to northwest,to the west of 103°E and within 37°N-39°N.展开更多
A comparative study of the structure and mechanical behavior of an Al-5 Mg-0.18 Mn-0.2 Sc-0.08 Zr-0.01 Fe-0.01 Si(wt.%)alloy ingot subjected to multidirectional isothermal forging(MIF)to a strain of 12 or equal-channe...A comparative study of the structure and mechanical behavior of an Al-5 Mg-0.18 Mn-0.2 Sc-0.08 Zr-0.01 Fe-0.01 Si(wt.%)alloy ingot subjected to multidirectional isothermal forging(MIF)to a strain of 12 or equal-channel angular pressing(ECAP)to a strain of 10 at 325℃,and subsequent warm and cold rolling(WR and CR)at 325 and 20℃,was performed.The results showed that the MIF process of ultrafine-grained structure with a(sub)grain size dUFG=2μm resulted in enhanced room-temperature ductility and superplastic elongation up to 2800%.Further grain refinement under WR as well as development of a heavily-deformed microstructure with high dislocation density by subsequent CR resulted in a yield/ultimate tensile strength increase from 235/360 MPa after MIF to 315/460 and 400/515 MPa after WR and CR,respectively.Simultaneously,WR led to improved superplastic elongation up to 4000%,while after CR the elongation remained sufficiently high(up to 1500%).Compared with MIF,ECAP resulted in more profound grain refinement(dUFG=1μm),which promoted higher strength and superplastic properties.However,this effect smoothed down upon WR,ensuring equal properties of the processed sheets.CR of the ECAPed alloy,in contrast,led to higher strengthening and slightly better superplastic behavior than those after CR following MIF.展开更多
CO2-rich cold springs occur near the active volcanoes at Wudalianchi （五大连池）, Northeast China. The springs are rich in CO2, with HCO3-as the predominant anion and have elevated contents of total dissolved solid ...CO2-rich cold springs occur near the active volcanoes at Wudalianchi （五大连池）, Northeast China. The springs are rich in CO2, with HCO3-as the predominant anion and have elevated contents of total dissolved solid （TDS） （〉1 000 mg/L）, Fe^2＋ （〉20 mg/L）, Sr （〉1 mg/L）, and dissolved Si （〉20 mg/L）. The compositions of escaped and dissolved gases of the springs are similar. The δ^13C values of escaped gases and dissolved gases in mineral springs at Wudalianchi vary from -8.77‰ to -4.53‰ and -8.24‰ to -5.26‰, while δ^18O values vary from -10.68‰ to -7.65‰ and -10.30‰ to -8.84‰, respectively, indicating the same upper mantle origin of CO2 of escaped gases and dissolved gases in the springs. Carbon and oxygen isotope fractionations and water-CO2 exchange were weak in the process of groundwater flow. The 4He content exceeds 5 000×10-6 cm^3·STP/mL in escaped gases of the mineral springs, and the 3He/4He ratios of the escaped and dissolved gases vary from 2.64Ra to 3.87Ra and 1.18Ra to 3.30Ra, respectively. It can be postulated that the CO2 of mineral springs deriving from the magma chamber of the upper mantle moves upward to the surface, to increase the content of 4He in the mineral springs and decrease the ratio of 3He/4He. The helium origin of escaped gases in springs can be calculated with the MORB-crust mixing model, but that in the north spring can be better explained with the MORB-crust-air mixing model due to the effect of mixing with surface water. However, dissolved helium in springs, except the north spring, is better explained with the MORB-crust-ASW mixing model.展开更多
Five species, namely Dasylabris adversa Skorikov, 1935, D. gussakovskii Skorikov, 1935, D.maura sungora（Pallas, 1773）, D. regalis（Fabricius, 1793） and D. zimini Skorikov, 1935, are recorded from China for the firs...Five species, namely Dasylabris adversa Skorikov, 1935, D. gussakovskii Skorikov, 1935, D.maura sungora（Pallas, 1773）, D. regalis（Fabricius, 1793） and D. zimini Skorikov, 1935, are recorded from China for the first time and illustrated. A key to the Chinese species of the genus Dasylabris is given.展开更多
The fate of subducted carbonates in the lower mantle and at the core-mantle boundary was modelled via experiments in the MgCO3-Fe^0 system at 70-150 GPa and 800-2600 Kin a laser-heated diamond anvil cell.Using in situ...The fate of subducted carbonates in the lower mantle and at the core-mantle boundary was modelled via experiments in the MgCO3-Fe^0 system at 70-150 GPa and 800-2600 Kin a laser-heated diamond anvil cell.Using in situ synchrotro n X-ray diffraction and ex situ transmission electron microscopy we show that the reduction of Mg-carbonate can be exemplified by:6 MgCO3+19 Fe=8 FeO+10(Mg0.6Fe^0.4)O+Fe7 C3+3 C.The presented results suggest that the interaction of carbonates with Fe^0 or Fe^0-bearing rocks can produce Fe-carbide and diamond,which can accumulate in the D"region,depending on its carbon to Fe ratio.Due to the sluggish kinetics of the transformation,diamond can remain metastable at the core-mantle boundary(CMB)unless it is in a direct contact with Fe-metal.In addition,it can be remobilized by redox melting accompanying the generation of mantle plumes.展开更多
Background:Ecological niche modeling of the main forest-forming species within the same geographic range contributes significantly to understanding the coexistence of species and the regularities of formation of their...Background:Ecological niche modeling of the main forest-forming species within the same geographic range contributes significantly to understanding the coexistence of species and the regularities of formation of their current spatial distribution.The main abiotic and biotic environmental variables,as well as species dispersal capability,affecting the spatial distribution of the main forest-forming species in the Caucasus,have not been sufficiently studied.Methods:We conducted studies within the physiographic boundaries of the Caucasus,including the Russian Federation,Georgia,Armenia,and Azerbaijan.Our studies focused on ecological niche modeling of pure fir,spruce,pine,beech,hornbeam,and birch forests through species distribution modeling and the concept of BAM(Biotic-Abiotic-Movement)diagram.We selected 648 geographic records of pure forests occurrence.ENVIREM and SoilGrids databases,statistical tools in R,Maxent were used to assess the influence of abiotic,biotic,and movement factors on the spatial distribution of the forest-forming species.Results:Geographic expression of fundamental ecological niches of the main forest-forming species depended mainly on topographic conditions and water regime.Competitor influence reduced the potential ranges of the studied species by 1.2–1.7 times to the geographic expression of their realized niches and led to differences in the distribution of species with similar requirements for abiotic conditions.Movement factor significantly limited the areas suitable for pure forests(by 1.2–1.8 times compared with geographic expression of realized ecological niches),except for birch forests.Conclusion:Distribution maps,constructed by abiotic,biotic,and movement factors,were the models of the occupied distributional area of the forest-forming species in the Caucasus.Biotic and movement factors should be considered in modeling studies of forest ecosystems if models are to have biological meaning and reality.展开更多
The typical development of total volumetric change in the focal areas of seismic events,corresponding to destress blasting,is characterized as an explosive phase followed by an implosive phase and with alternating add...The typical development of total volumetric change in the focal areas of seismic events,corresponding to destress blasting,is characterized as an explosive phase followed by an implosive phase and with alternating additional phases following on from that.In a few cases,a non-typical development of volumetric change was identified,where the first phase was implosive and the second phase,explosive.This development is mainly typical for induced seismic events recorded during mining,not for destress blasting.Seismic events were recorded during longwall mining in the Czech part of the Upper Silesian Coal Basin,where the destress blasting technique is used as a rockburst prevention active measure.Kinematic source processes in the focal areas of selected seismic events were analyzed by the seismic moment tensor inversion method,as well as by studying geomechanical rock mass conditions at the localities of the seismic events.The main goal of the analysis was to attempt to identify the reasons for non-typical development of volumetric changes in these cases.Volumetric changes were analyzed for seismic events with energy greater than 104 J,recorded in the period of time from 1993 to 2009(1109 events).80%(891)of the recorded seismic events were induced seismic events that were registered during longwall mining and 20%(218)corresponded to destress blasting events.Research shows that the main reason for the non-typical development of volumetric changes in the focal areas of seismic events is an association with destress blasting in the rock mass,which is very close to rock mass overstressing.The detonation of explosives in boreholes,which would dominate the first phase of volumetric changes,probably obscured stress release in the rock mass,as manifested in the first implosion phase of the volumetric changes in this case.展开更多
Abiotic factors play an important role in species localisation,but biotic and anthropogenic predictors must also be considered in distribution modelling for models to be biologically meaningful.In this study,we formal...Abiotic factors play an important role in species localisation,but biotic and anthropogenic predictors must also be considered in distribution modelling for models to be biologically meaningful.In this study,we formalised the biotic predictors of nesting sites for four threatened Caucasian vultures by including species distribution models(wild ungulates,nesting tree species)as biotic layers in the vulture Maxent models.Maxent was applied in the R dismo package and the best set of the model parameters were defined in the R ENMeval package.Performance metrics were continuous Boyce index,Akaike's information criterion,the area under receiver operating curve and true skill statistics.We also calculated and evaluated the null models.Kernel density estimation method was applied to assess the overlap of vulture ecological niches in the environmental space.The accessibility of anthropogenic food resources was estimated using the Path Distance measure that considers elevation gradient.The availability of pine forests(Scots Pine)and wild ungulates(Alpine Chamois and Caucasian Goat)contributed the most(29.6%and 34.3%)to Cinereous Vulture(Aegypius monachus)nesting site model.Wild ungulate distribution also contributed significantly(about 46%)to the Bearded Vulture(Gypaetus barbatus)model.This scavenger nests in the highlands of the Caucasus at a minimum distance of 5–10 km from anthropogenic facilities.In contrast,livestock as a food source was most important in colony distribution of Griffon Vulture(Gyps fulvus).The contribution of distances to settlements and agricultural facilities to the model was 45%.The optimal distance from Egyptian Vulture(Neophron percnopterus)nesting sites to settlements was only 3–10 km,to livestock facilities no more than 15 km with the factor contribution of about 57%.Excluding the wild ungulate availability,the ecological niches of studied vultures overlapped significantly.Despite similar foraging and nesting requirements,Caucasian vultures are not pronounced nesting and trophic competitors due to the abundance of nesting sites,anthropogenic food sources and successful niche sharing.展开更多
Composites based on ultradispersed polytetrafluoroethylene and intercalated graphite oxide compounds with dodecahydro-closo-dodecaborates and methods of their fabrication have been developed. The fabricated composites...Composites based on ultradispersed polytetrafluoroethylene and intercalated graphite oxide compounds with dodecahydro-closo-dodecaborates and methods of their fabrication have been developed. The fabricated composites have been characterized using XRD analysis, and optical microscopy. These composites are distinguished with completeness of their combustion, since the combustion products comprise gaseous boron fluorine-containing compounds of boron, boron trifluoride (BF3), and boron oxyfluoride ((BOF)3). Besides, these composites are characterized with increased energy capacity as compared to purely oxygen-containing compounds, since the heat of formation of boron fluorine-containing compounds is higher than that of boron oxide. Introduction of ultradispersed polytetrafluoroethylene imparts composites with hydrophobicity, thus improving their functioning properties.展开更多
We present here for the first time,the Raman and infrared spectroscopic investigation of amphiboles from the World's deepest borehole,the Kola super-deep borehole,at the depth of 11.66 km.The Kola Super-deep boreh...We present here for the first time,the Raman and infrared spectroscopic investigation of amphiboles from the World's deepest borehole,the Kola super-deep borehole,at the depth of 11.66 km.The Kola Super-deep borehole(SG-3)(henceforth referred as KSDB)is located in the northwest of the Kola Peninsula in the northern frame of the Pechenga structure,Russia.It was drilled in the north-eastern part of the Baltic Shield(69о5’N,30о44’E)and reached a depth of 12.262 km.It has been drilled in the northern limb of the Pechenga geosyncline composed of rhythmically inter-bedded volcanogenic and tuffaceous-sedimentary strata extending to the NW at 300°–310°and dipping to SW at angles of 30°–50°.The SG-3 geological section is represented by two complexes–Proterozoic and Archaean.Amphibolite facies is dominant in the depth region from 6000 m to 12,000m to the deepest.The Raman spectra of the sample reveal abundant presence of plagioclase and amphiboles.The most distinct Raman peak in this study indicates the tremolite-ferro-actinolite rich enrichment of the borehole samples at this depth corroborating earlier conventional petrographic studies.展开更多
Efficient coupling of terahertz electromagnetic wave with the active region in a terahertz detector is required to enhance the optical sensitivity.In this work,we demonstrate direct integration of a field-effect-trans...Efficient coupling of terahertz electromagnetic wave with the active region in a terahertz detector is required to enhance the optical sensitivity.In this work,we demonstrate direct integration of a field-effect-transistor(FET)terahertz detector chip at the waveguide port of a horn antenna.Although the integration without a proper backshot is rather preliminary,the noise-equivalent power is greatly reduced from 2.7 nW/Hz^(1/2)for the bare detector chip to 76 pW/Hz^(1/2)at340 GHz.The enhancement factor of about 30 is confirmed by simulations revealing the effective increase in the energy flux density seen by the detector.The simulation further confirms the frequency response of the horn antenna and the onchip antennas.A design with the detector chip fully embedded within a waveguide cavity could be made to further enhance the coupling efficiency.展开更多
Cardiovascular diseases and diabetes mellitus are leading causes of mortality in modern society. The search for a novel effective remedy represents an important task for modern medicine. A total mixture of phospho- an...Cardiovascular diseases and diabetes mellitus are leading causes of mortality in modern society. The search for a novel effective remedy represents an important task for modern medicine. A total mixture of phospho- and glycolipids from sea macrophytes Sargassum pallidum, Ulva fenestrata, Zostera marina was separated and the fatty acid composition was determined. The biological activity of the mixtures of polar lipids and natural redox-active compounds (echinochrome A from the flat sea urchin Scaphechinus mirabilis and a polyphenolic complex from the sea grass Zostera marina) was studied under conditions of impairments of carbohydrate and lipid metabolism. Doses and compositions of mixtures of pola lipids and redox-active compounds possessing high corrective activity were optimized in mice with the experimental model of hyperlipidemia and diabetes. Based on these results possible mechanisms of the effects of polar lipids containing various polyunsaturated fatty acids and the investigated redox-active compounds (echinochrome A, rosmarinic acid, luteolin and its sulphate conjugates) have been proposed. The developed compositions may be used for creation of new biologically active additives and remedies.展开更多
Thermal diffusivity, specific heat capacity and thermal conductivity of AI86Gd6TM8 （TM = Cu, Ni, Co, Fe, Mn, Cr, Ti, Zr, Mo, Ta） glass-forming alloys in the temperature range of 300-880 K were determined by laser fl...Thermal diffusivity, specific heat capacity and thermal conductivity of AI86Gd6TM8 （TM = Cu, Ni, Co, Fe, Mn, Cr, Ti, Zr, Mo, Ta） glass-forming alloys in the temperature range of 300-880 K were determined by laser flash method. The temperatures of endothermic and exothermic reactions of the alloys were determined by differential scanning calorimetry method. The alloys were prepared by conventional arc-melting technique under helium atmosphere. All the alloys studied exhibit strong supercooling of the liquidus temperatures up to 80 K, which indicates their good glass-forming ability. The specific heat capacity of the alloys achieves the Dulong-Petit＇s value in the temperature range of 350-550 K except Als6CrsGd6 and Als6ZrsGd6 compositions. The values of both thermal diffusivity and thermal conductivity of the alloy studied are significantly lower than those for pure aluminum. It is found that embedding 14% （mole fraction） of transition elements （Gd＋TM） in the aluminum matrix leads to significant decrease in the absolute magnitudes of both thermal diffusivity and thermal conductivity in crystalline state. The thermal conductivity of glass-forming Als6Gd6TMs alloys is strongly affected by directed chemical bonding between alloy components.展开更多
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 ...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.展开更多
It has been proved that there exists a certain cor relation between fingertip temperature oscillations and blood flow oscillations. In this work, a porous media model of hu man hand is presented to investigate how the...It has been proved that there exists a certain cor relation between fingertip temperature oscillations and blood flow oscillations. In this work, a porous media model of hu man hand is presented to investigate how the blood flow os cillation in the endothelial frequency band influences finger tip skin temperature oscillations. The porosity which repre sents the density of micro vessels is assumed to vary periodi cally and is a function of the skin temperature. Finite element analysis of skin temperature for a contra lateral hand under a cooling test was conducted. Subsequently, wavelet anal ysis was carried out to extract the temperature oscillations of the data through the numerical analysis and experimen tal measurements. Furthermore, the oscillations extracted from both numerical analyses and experiments were statis tically analyzed to compare the amplitude. The simulation and experimental results show that for the subjects in cardio vascular health, the skin temperature fluctuations in endothe lial frequency decrease during the cooling test and increase gradually after cooling, implying that the assumed porosity variation can represent the vasomotion in the endothelial fre quency band.展开更多
A linear theory on the internal waves generated in the stratified fluid with a pycnocline is presented in this paper. The internal wave fields such as the velocity fields in the stratified fluid and velocity gradient ...A linear theory on the internal waves generated in the stratified fluid with a pycnocline is presented in this paper. The internal wave fields such as the velocity fields in the stratified fluid and velocity gradient fields at the free surface are also investigated by means of the theoretical and numerical method. From the numerical results, it is shown that the internal wave generated by horizontally moving Rankine ovoid is a sort of trapped wave which propagates in a wave guide, and its waveform is a kind of Mach front-type internal wave in the pycnocline. Influence of the internal wave on the flow fields at the free surface is represented by the velocity gradient fields resulted from the internal waves generated by motion of the Rankine ovoid. At the same time, it is also shown that under the hypothesis of inviscid fluid, the synchronism between the surface velocity gradient fields at the free surface and the internal wave fields in the fluid is retained. This theory opens a possibility to study further the modulated spectrum of the Bragg waves at the free surface.展开更多
During oil and gas fields development,a decrease in reservoir and bottomhole pressure has often a detrimental effect on reservoir properties,especially permeability.This study presents the results of laboratory tests ...During oil and gas fields development,a decrease in reservoir and bottomhole pressure has often a detrimental effect on reservoir properties,especially permeability.This study presents the results of laboratory tests conducted to determine the response of terrigenous reservoir core-sample permeability to changes in the effective stresses and a decrease in the reservoir pressure.The considered samples were exposed for a long time to a constant high effective stress for a more reliable assessment of the viscoplastic deformations.According to these experiments,the decrease of the core samples permeability may reach 21%with a decrease in pressure by 9.5 MPa from the initial reservoir conditions.Numerical simulations have been also conducted.These have been based on the finite element modeling of the near-wellbore zone of the terrigenous reservoir using poroelasticity relations.The simulation results show a limited decrease in reservoir permeability in the near-wellbore zone(by 17%,which can lead to a decrease in the well productivity by 13%).展开更多
文摘Reconstruction of characteristics of sedimentary environments of the Lower Paleozoic Sandstone (hereafter LPS) sequence in the northwestern Russian platform based on granulometric and texture analyses reveals high paleohydrodynamic conditions of sedimentation which decrease to moderate in south-east direction. Determination of quantitative paleolithodynamic parameters showed that the real sedimentation duration was considerably less than the related stratigraphic scale interval that is evidence of long interrupt of sedimentation and re-deposition of the clastic material. Study of paleolithodynamics is significant both for reconstruction of the paleobasin history and assessment of mineral resources.
基金supported by the Tomsk State University Development Program(《Priority-2030》)the Basic Project of the Federal Research Center of the Scientific Center,no.FWES-2024-0023the Russian Science Foundation(project No.23-14-20015)。
文摘The growth,survival,and mortality of conifer species in response to the hydrothermal regime have received considerable attention.It is expected that the highest sensitivity of trees to the warming-drying climate will occur mainly at the edges of the species ranges.We focused on the responses to climate change of the drought-resistant larch(Larix sibirica)and the moisture-sensitive Siberian pine(Pinus sibirica)along the elevation gradient in the Tannu-Ola Ridge,the southern margin where those two species coexist in Siberia by using satellite data(MODIS,Landsat,and microwave),the indexes of gross(GPP)and net(NPP)primary productivity,and tree radial growth index(GI).We found that since the warming restart in the 2000s,the area of larch-dominated forests increased by~150%while the area of pine-dominated forests decreased by~10%.The Siberian pine has retreated at low elevations(<1800 m)and increased its area at higher ones.In contrast,the area of larch stands increased in both the uphill and downhill directions.Birch(Betula spp.)also increased its area at low elevations(about+120%).Since 2001,the forested area increased by~5%.A shrubification,i.e.,an increase in the area of shrubs,was observed at high elevations.The uphill rate of timberline and shrubline migration was about 0.3 m/a.Since the 2000s,vegetation NPP has increased by 13%.A notable correlation between NPP and the GI of larch and pine was found(r=0.5-0.7).At lower elevations,NPP positively correlated with precipitation and soil moisture,while air temperature and VPD(vapor pressure deficit)increase inhibited productivity.At high elevations,the effects of these variables on productivity reversed.The continuous decline of the Siberian pine forest indicates an inevitable retreat of this species at low elevations and its replacement by larch and birch.
基金partly supported by the NSFC-RSF Joint Research project(Nos.42261134534,23-47-00035)funded by the Chinese Academy of Sciences President’s International Fellowship Initiative(Nos.2024VCA0006,2024VCB0013)the National Natural Science Foundation of China(No.42442006)。
文摘The phenomenon of mud volcanism has a connection with the processes of hydrocarbon generation.However,the genesis of sediments is not often taken into consideration.The study of mud volcanoes in the West Kuban marginal marine basin and the Junggar freshwater basin revealed significant isotope-geochemical differences due to various types of sedimentation.The waters from both basins exhibit three principal geochemical facies:Na-HCO_(3),Na-Cl-HCO_(3),and Na-Cl,of which the latter type of water is the dominant.The analysis of genetic coefficients(Cl/Br,Na/Br,and B/Cl)allowed us to distinguish different pathways of mud volcanic water evolution:evaporite dissolution,formation(sedimentation)waters,and waters formed by active water-rock interaction.Through statistical research,we were able to determine that noticeable variations in the behavior of chemical elements in waters from different areas can reflect discrepancies in the geological environment and the evolutionary stage of the diagenetic water transformation.Using thermodynamic modeling,the main directions of mass transfer were shown.It was established that the waters of the Junggar Basin were at a relatively early stage of evolution and had reached equilibrium only with carbonates,while in the formation waters of the West Kuban Basin,element concentrations were also controlled by silicate minerals.The correlations betweenδ^(18)O andδ~2H values and saturation indices of halides,aluminosilicates,sulfates,and borates confirm the enrichment of water with heavy isotopes during interactions with rocks without evaporation or thermal water partition.These reactions are characterized by clay dehydration and water enrichment with^(18)O and B.The data obtained made it possible to clarify the depths of formation of mud-volcanic fluids and their possible stratigraphic sources.
基金supported by the National Natural Science Foundation of China(Grants Nos.42130511,42261134537 and 41602192)funded by the Russian Science Foundation(Grant No.23-44-00067)+2 种基金supported by the Swedish Research Council(Vetenskaps lijeradet,Grant No.2023-00605)the Marianne and Marcus Wallenberg Foundation(Grant No.MMW 2022-0114)the Centre for Advanced Study(CAS)at the Norwegian Academy of Science and Letters,which funded and hosted the research project“The Nordic Little Ice Age”during the 2024-2025 academic year。
文摘Radial growth of trees is highly sensitive to environmental changes,but the effect of climate on tree rings in Qinghai spruce(Picea crassifolia),a widely distributed endemic conifer in western China,is more complex than in many other conifers.A comprehensive understanding of the spatiotemporal climatic responses of its rings is needed to develop theoretical basis for designing strategies for its conservation and management.Here,our synthesis of the literature on responses of radial growth of Qinghai spruce to monthly climate variables in different environmental conditions by meta-analysis showed that precipitation and drought severity are the main limiting factors for Qinghai spruce radial growth in the semiarid region of northwestern China.In warmer and drier areas,radial growth of Qinghai spruce is mainly limited by drought.In the areas north of the 600-mm annual precipitation isoline,the tree-ring width(TRW)was significantly positively correlated with precipitation and significantly negatively correlated with temperature during the growing season(June-August).The limiting effect of drought on Qinghai spruce is also gradually increasing from southeast to northwest,to the west of 103°E and within 37°N-39°N.
基金financial supports from the Russian Science Foundation under grant No.16-19-10152P(the alloy MIF processing and room-temperature mechanical testing)by the Ministry of Science and Higher Education of Russia under the state assignment of IMSP RAS(ECAP and analysis of superplasticity).
文摘A comparative study of the structure and mechanical behavior of an Al-5 Mg-0.18 Mn-0.2 Sc-0.08 Zr-0.01 Fe-0.01 Si(wt.%)alloy ingot subjected to multidirectional isothermal forging(MIF)to a strain of 12 or equal-channel angular pressing(ECAP)to a strain of 10 at 325℃,and subsequent warm and cold rolling(WR and CR)at 325 and 20℃,was performed.The results showed that the MIF process of ultrafine-grained structure with a(sub)grain size dUFG=2μm resulted in enhanced room-temperature ductility and superplastic elongation up to 2800%.Further grain refinement under WR as well as development of a heavily-deformed microstructure with high dislocation density by subsequent CR resulted in a yield/ultimate tensile strength increase from 235/360 MPa after MIF to 315/460 and 400/515 MPa after WR and CR,respectively.Simultaneously,WR led to improved superplastic elongation up to 4000%,while after CR the elongation remained sufficiently high(up to 1500%).Compared with MIF,ECAP resulted in more profound grain refinement(dUFG=1μm),which promoted higher strength and superplastic properties.However,this effect smoothed down upon WR,ensuring equal properties of the processed sheets.CR of the ECAPed alloy,in contrast,led to higher strengthening and slightly better superplastic behavior than those after CR following MIF.
基金supported by the National Natural Science Foundation of China(Nos.40425001,40602031,40830748),and Russian Fund for Basic Research
文摘CO2-rich cold springs occur near the active volcanoes at Wudalianchi （五大连池）, Northeast China. The springs are rich in CO2, with HCO3-as the predominant anion and have elevated contents of total dissolved solid （TDS） （〉1 000 mg/L）, Fe^2＋ （〉20 mg/L）, Sr （〉1 mg/L）, and dissolved Si （〉20 mg/L）. The compositions of escaped and dissolved gases of the springs are similar. The δ^13C values of escaped gases and dissolved gases in mineral springs at Wudalianchi vary from -8.77‰ to -4.53‰ and -8.24‰ to -5.26‰, while δ^18O values vary from -10.68‰ to -7.65‰ and -10.30‰ to -8.84‰, respectively, indicating the same upper mantle origin of CO2 of escaped gases and dissolved gases in the springs. Carbon and oxygen isotope fractionations and water-CO2 exchange were weak in the process of groundwater flow. The 4He content exceeds 5 000×10-6 cm^3·STP/mL in escaped gases of the mineral springs, and the 3He/4He ratios of the escaped and dissolved gases vary from 2.64Ra to 3.87Ra and 1.18Ra to 3.30Ra, respectively. It can be postulated that the CO2 of mineral springs deriving from the magma chamber of the upper mantle moves upward to the surface, to increase the content of 4He in the mineral springs and decrease the ratio of 3He/4He. The helium origin of escaped gases in springs can be calculated with the MORB-crust mixing model, but that in the north spring can be better explained with the MORB-crust-air mixing model due to the effect of mixing with surface water. However, dissolved helium in springs, except the north spring, is better explained with the MORB-crust-ASW mixing model.
基金provided by the State Key Program of National Natural Science Foundation of China(31230068)the 973 Program(2013CB127600)
文摘Five species, namely Dasylabris adversa Skorikov, 1935, D. gussakovskii Skorikov, 1935, D.maura sungora（Pallas, 1773）, D. regalis（Fabricius, 1793） and D. zimini Skorikov, 1935, are recorded from China for the first time and illustrated. A key to the Chinese species of the genus Dasylabris is given.
基金supported byRussian Science Foundation,project No 17-17-01177.AGsupport of the Deep Carbon Observatory through the Alfred P.Sloan Foundation
文摘The fate of subducted carbonates in the lower mantle and at the core-mantle boundary was modelled via experiments in the MgCO3-Fe^0 system at 70-150 GPa and 800-2600 Kin a laser-heated diamond anvil cell.Using in situ synchrotro n X-ray diffraction and ex situ transmission electron microscopy we show that the reduction of Mg-carbonate can be exemplified by:6 MgCO3+19 Fe=8 FeO+10(Mg0.6Fe^0.4)O+Fe7 C3+3 C.The presented results suggest that the interaction of carbonates with Fe^0 or Fe^0-bearing rocks can produce Fe-carbide and diamond,which can accumulate in the D"region,depending on its carbon to Fe ratio.Due to the sluggish kinetics of the transformation,diamond can remain metastable at the core-mantle boundary(CMB)unless it is in a direct contact with Fe-metal.In addition,it can be remobilized by redox melting accompanying the generation of mantle plumes.
基金This work was supported by the state assignment“Patterns of the Spatiotemporal Dynamics of Meadow and Forest Ecosystems in Moun-tainous Areas(Russian Western and Central Caucasus)”,No.075-00347-19-00.
文摘Background:Ecological niche modeling of the main forest-forming species within the same geographic range contributes significantly to understanding the coexistence of species and the regularities of formation of their current spatial distribution.The main abiotic and biotic environmental variables,as well as species dispersal capability,affecting the spatial distribution of the main forest-forming species in the Caucasus,have not been sufficiently studied.Methods:We conducted studies within the physiographic boundaries of the Caucasus,including the Russian Federation,Georgia,Armenia,and Azerbaijan.Our studies focused on ecological niche modeling of pure fir,spruce,pine,beech,hornbeam,and birch forests through species distribution modeling and the concept of BAM(Biotic-Abiotic-Movement)diagram.We selected 648 geographic records of pure forests occurrence.ENVIREM and SoilGrids databases,statistical tools in R,Maxent were used to assess the influence of abiotic,biotic,and movement factors on the spatial distribution of the forest-forming species.Results:Geographic expression of fundamental ecological niches of the main forest-forming species depended mainly on topographic conditions and water regime.Competitor influence reduced the potential ranges of the studied species by 1.2–1.7 times to the geographic expression of their realized niches and led to differences in the distribution of species with similar requirements for abiotic conditions.Movement factor significantly limited the areas suitable for pure forests(by 1.2–1.8 times compared with geographic expression of realized ecological niches),except for birch forests.Conclusion:Distribution maps,constructed by abiotic,biotic,and movement factors,were the models of the occupied distributional area of the forest-forming species in the Caucasus.Biotic and movement factors should be considered in modeling studies of forest ecosystems if models are to have biological meaning and reality.
基金the project of the Institute of Clean Technologies for Mining and Utilisation of Raw Materials for Energy Use–Sustainability Programme(No.LO1406)supported by a project for the long-term conceptual development of research organisations(No.RVO68145535)
文摘The typical development of total volumetric change in the focal areas of seismic events,corresponding to destress blasting,is characterized as an explosive phase followed by an implosive phase and with alternating additional phases following on from that.In a few cases,a non-typical development of volumetric change was identified,where the first phase was implosive and the second phase,explosive.This development is mainly typical for induced seismic events recorded during mining,not for destress blasting.Seismic events were recorded during longwall mining in the Czech part of the Upper Silesian Coal Basin,where the destress blasting technique is used as a rockburst prevention active measure.Kinematic source processes in the focal areas of selected seismic events were analyzed by the seismic moment tensor inversion method,as well as by studying geomechanical rock mass conditions at the localities of the seismic events.The main goal of the analysis was to attempt to identify the reasons for non-typical development of volumetric changes in these cases.Volumetric changes were analyzed for seismic events with energy greater than 104 J,recorded in the period of time from 1993 to 2009(1109 events).80%(891)of the recorded seismic events were induced seismic events that were registered during longwall mining and 20%(218)corresponded to destress blasting events.Research shows that the main reason for the non-typical development of volumetric changes in the focal areas of seismic events is an association with destress blasting in the rock mass,which is very close to rock mass overstressing.The detonation of explosives in boreholes,which would dominate the first phase of volumetric changes,probably obscured stress release in the rock mass,as manifested in the first implosion phase of the volumetric changes in this case.
基金the State Assignment,project 075-00347-19-00(Patterns of the spatiotemporal dynamics of meadow and forest ecosystems in mountainous areas(Russian Western and Central Caucasus)WWF's‘Save the Forest-Home of Raptors’project(2020-2022).
文摘Abiotic factors play an important role in species localisation,but biotic and anthropogenic predictors must also be considered in distribution modelling for models to be biologically meaningful.In this study,we formalised the biotic predictors of nesting sites for four threatened Caucasian vultures by including species distribution models(wild ungulates,nesting tree species)as biotic layers in the vulture Maxent models.Maxent was applied in the R dismo package and the best set of the model parameters were defined in the R ENMeval package.Performance metrics were continuous Boyce index,Akaike's information criterion,the area under receiver operating curve and true skill statistics.We also calculated and evaluated the null models.Kernel density estimation method was applied to assess the overlap of vulture ecological niches in the environmental space.The accessibility of anthropogenic food resources was estimated using the Path Distance measure that considers elevation gradient.The availability of pine forests(Scots Pine)and wild ungulates(Alpine Chamois and Caucasian Goat)contributed the most(29.6%and 34.3%)to Cinereous Vulture(Aegypius monachus)nesting site model.Wild ungulate distribution also contributed significantly(about 46%)to the Bearded Vulture(Gypaetus barbatus)model.This scavenger nests in the highlands of the Caucasus at a minimum distance of 5–10 km from anthropogenic facilities.In contrast,livestock as a food source was most important in colony distribution of Griffon Vulture(Gyps fulvus).The contribution of distances to settlements and agricultural facilities to the model was 45%.The optimal distance from Egyptian Vulture(Neophron percnopterus)nesting sites to settlements was only 3–10 km,to livestock facilities no more than 15 km with the factor contribution of about 57%.Excluding the wild ungulate availability,the ecological niches of studied vultures overlapped significantly.Despite similar foraging and nesting requirements,Caucasian vultures are not pronounced nesting and trophic competitors due to the abundance of nesting sites,anthropogenic food sources and successful niche sharing.
文摘Composites based on ultradispersed polytetrafluoroethylene and intercalated graphite oxide compounds with dodecahydro-closo-dodecaborates and methods of their fabrication have been developed. The fabricated composites have been characterized using XRD analysis, and optical microscopy. These composites are distinguished with completeness of their combustion, since the combustion products comprise gaseous boron fluorine-containing compounds of boron, boron trifluoride (BF3), and boron oxyfluoride ((BOF)3). Besides, these composites are characterized with increased energy capacity as compared to purely oxygen-containing compounds, since the heat of formation of boron fluorine-containing compounds is higher than that of boron oxide. Introduction of ultradispersed polytetrafluoroethylene imparts composites with hydrophobicity, thus improving their functioning properties.
基金National Institute of advanced Studies (NIAS)Indian National Science Academy (INSA) for the support in under the INSA senior Scientist scheme.
文摘We present here for the first time,the Raman and infrared spectroscopic investigation of amphiboles from the World's deepest borehole,the Kola super-deep borehole,at the depth of 11.66 km.The Kola Super-deep borehole(SG-3)(henceforth referred as KSDB)is located in the northwest of the Kola Peninsula in the northern frame of the Pechenga structure,Russia.It was drilled in the north-eastern part of the Baltic Shield(69о5’N,30о44’E)and reached a depth of 12.262 km.It has been drilled in the northern limb of the Pechenga geosyncline composed of rhythmically inter-bedded volcanogenic and tuffaceous-sedimentary strata extending to the NW at 300°–310°and dipping to SW at angles of 30°–50°.The SG-3 geological section is represented by two complexes–Proterozoic and Archaean.Amphibolite facies is dominant in the depth region from 6000 m to 12,000m to the deepest.The Raman spectra of the sample reveal abundant presence of plagioclase and amphiboles.The most distinct Raman peak in this study indicates the tremolite-ferro-actinolite rich enrichment of the borehole samples at this depth corroborating earlier conventional petrographic studies.
基金supported by the National Key Research and Development Program of China(Grant Nos.2016YFF0100501 and 2016YFC0801203)the National Natural Science Foundation of China(Grant Nos.61611530708,11403084,61401456,61401297,and 61505242)+2 种基金the Six Talent Peaks Project of Jiangsu Province,China(Grant No.XXRJ-079)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2017372)the Russian Foundation for Basic Research(Grant No.17-52-53063)
文摘Efficient coupling of terahertz electromagnetic wave with the active region in a terahertz detector is required to enhance the optical sensitivity.In this work,we demonstrate direct integration of a field-effect-transistor(FET)terahertz detector chip at the waveguide port of a horn antenna.Although the integration without a proper backshot is rather preliminary,the noise-equivalent power is greatly reduced from 2.7 nW/Hz^(1/2)for the bare detector chip to 76 pW/Hz^(1/2)at340 GHz.The enhancement factor of about 30 is confirmed by simulations revealing the effective increase in the energy flux density seen by the detector.The simulation further confirms the frequency response of the horn antenna and the onchip antennas.A design with the detector chip fully embedded within a waveguide cavity could be made to further enhance the coupling efficiency.
文摘Cardiovascular diseases and diabetes mellitus are leading causes of mortality in modern society. The search for a novel effective remedy represents an important task for modern medicine. A total mixture of phospho- and glycolipids from sea macrophytes Sargassum pallidum, Ulva fenestrata, Zostera marina was separated and the fatty acid composition was determined. The biological activity of the mixtures of polar lipids and natural redox-active compounds (echinochrome A from the flat sea urchin Scaphechinus mirabilis and a polyphenolic complex from the sea grass Zostera marina) was studied under conditions of impairments of carbohydrate and lipid metabolism. Doses and compositions of mixtures of pola lipids and redox-active compounds possessing high corrective activity were optimized in mice with the experimental model of hyperlipidemia and diabetes. Based on these results possible mechanisms of the effects of polar lipids containing various polyunsaturated fatty acids and the investigated redox-active compounds (echinochrome A, rosmarinic acid, luteolin and its sulphate conjugates) have been proposed. The developed compositions may be used for creation of new biologically active additives and remedies.
基金Project(13-02-96036) supported by RFBR and the Government of Sverdlovsk Region of Russia
文摘Thermal diffusivity, specific heat capacity and thermal conductivity of AI86Gd6TM8 （TM = Cu, Ni, Co, Fe, Mn, Cr, Ti, Zr, Mo, Ta） glass-forming alloys in the temperature range of 300-880 K were determined by laser flash method. The temperatures of endothermic and exothermic reactions of the alloys were determined by differential scanning calorimetry method. The alloys were prepared by conventional arc-melting technique under helium atmosphere. All the alloys studied exhibit strong supercooling of the liquidus temperatures up to 80 K, which indicates their good glass-forming ability. The specific heat capacity of the alloys achieves the Dulong-Petit＇s value in the temperature range of 350-550 K except Als6CrsGd6 and Als6ZrsGd6 compositions. The values of both thermal diffusivity and thermal conductivity of the alloy studied are significantly lower than those for pure aluminum. It is found that embedding 14% （mole fraction） of transition elements （Gd＋TM） in the aluminum matrix leads to significant decrease in the absolute magnitudes of both thermal diffusivity and thermal conductivity in crystalline state. The thermal conductivity of glass-forming Als6Gd6TMs alloys is strongly affected by directed chemical bonding between alloy components.
文摘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.
基金supported by Anhui Provincial Natural Science Foundation of China(11040606M09)
文摘It has been proved that there exists a certain cor relation between fingertip temperature oscillations and blood flow oscillations. In this work, a porous media model of hu man hand is presented to investigate how the blood flow os cillation in the endothelial frequency band influences finger tip skin temperature oscillations. The porosity which repre sents the density of micro vessels is assumed to vary periodi cally and is a function of the skin temperature. Finite element analysis of skin temperature for a contra lateral hand under a cooling test was conducted. Subsequently, wavelet anal ysis was carried out to extract the temperature oscillations of the data through the numerical analysis and experimen tal measurements. Furthermore, the oscillations extracted from both numerical analyses and experiments were statis tically analyzed to compare the amplitude. The simulation and experimental results show that for the subjects in cardio vascular health, the skin temperature fluctuations in endothe lial frequency decrease during the cooling test and increase gradually after cooling, implying that the assumed porosity variation can represent the vasomotion in the endothelial fre quency band.
基金The project supported by the National Natural Science Foundation of China (40576010). The English text was polished by Keren Wang
文摘A linear theory on the internal waves generated in the stratified fluid with a pycnocline is presented in this paper. The internal wave fields such as the velocity fields in the stratified fluid and velocity gradient fields at the free surface are also investigated by means of the theoretical and numerical method. From the numerical results, it is shown that the internal wave generated by horizontally moving Rankine ovoid is a sort of trapped wave which propagates in a wave guide, and its waveform is a kind of Mach front-type internal wave in the pycnocline. Influence of the internal wave on the flow fields at the free surface is represented by the velocity gradient fields resulted from the internal waves generated by motion of the Rankine ovoid. At the same time, it is also shown that under the hypothesis of inviscid fluid, the synchronism between the surface velocity gradient fields at the free surface and the internal wave fields in the fluid is retained. This theory opens a possibility to study further the modulated spectrum of the Bragg waves at the free surface.
基金The research was completed with the support of the grant of the President of the Russian Federation for state support of leading scientific schools of the Russian Federation(Grant No.NSh-1010.2022.1.5).
文摘During oil and gas fields development,a decrease in reservoir and bottomhole pressure has often a detrimental effect on reservoir properties,especially permeability.This study presents the results of laboratory tests conducted to determine the response of terrigenous reservoir core-sample permeability to changes in the effective stresses and a decrease in the reservoir pressure.The considered samples were exposed for a long time to a constant high effective stress for a more reliable assessment of the viscoplastic deformations.According to these experiments,the decrease of the core samples permeability may reach 21%with a decrease in pressure by 9.5 MPa from the initial reservoir conditions.Numerical simulations have been also conducted.These have been based on the finite element modeling of the near-wellbore zone of the terrigenous reservoir using poroelasticity relations.The simulation results show a limited decrease in reservoir permeability in the near-wellbore zone(by 17%,which can lead to a decrease in the well productivity by 13%).
