检索结果-南通市图书馆

地球环境学报 2011年第1期 307-308页

作者： AN Zhi-sheng kashiwaya k Prokopenko A State key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of Sciences Institute of Nature and Environmental Technology Kanazawa University Department of Earth and Ocean Sciences University of South Carolina

On November 7—9,2010,the 8th International Symposium"Environmental Processes of East Eurasia:Asian Monsoon Changes and Interplay of High and Low Latitude Climate"took place in kunming,*** is the most recent of the series of annual to bi-annual Symposia,previously held in Mongolia,Russia,Japan,korea and *** addition to representatives of research institutions from these countries,the Symposium was also attended

关键词： Environmental processes of East Eurasia

Mineralogy of long drill core from Darkhad Basin in northern Mongolia

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

地球环境学报 2011年第1期 312-313页

作者： Fukushi k Fuchizaki M Hasebe N kashiwaya k Institute of Nature and Environmental Technology Kanazawa University

Darkhad Basin in northern Mongolia was former dammed lake during Pleistocene *** basin is located in the inside of continent where is sensitive to the climate *** lake sediments are expected to possess the paleo-environmental records like the sediments from Lake Baikal and *** long drill cores were obtained from the Darkhad Basin at winter of *** study is first report for the mineralogy of the long drill core from the Darkhad ***10-3 core(alternatively "Hodon core";51°20'11 "N,99°30'4" E;length about 164 m) was used for the mineralogical *** sample was cut into 3 cm and analyzed from top to 30 m by means of X-ray powder diffraction(XRD) after *** analyses of bulk sample show that the constituent minerals present in the sediments were quartz,feldspar,amphibole,calcite,dolomite,mica chlorite and ***,feldspar,amphibole,chlorite,mica and smectite were found in samples from all *** some samples contain carbonate minerals(calcite and dolomite) whereas some samples do *** samples with calcite usually contain *** is no systematic tendency of the presence or absence of carbonate minerals with *** formation and dissolution rate of carbonate minerals are much higher than the other constituent *** indicates that carbonate minerals disappear(or appear) during some periods as response to changes of water chemistry of the *** water chemistry is usually affected by surround *** preliminary study suggests that the carbonate mineralogy can be regarded as possible proxy for the paleo-environment in Darkhad Basin.

关键词： Darkhad Basin long drill core mineralogy carbonate calcite dolomite

Holocene sedimentary records in Inner Continental Asia:Mongolian Plateau and Tibetan Plateau

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

地球环境学报 2011年第1期 320-321页

作者： Orkhonselenge A kashiwaya k krivonogov S Nakamura S Institute of Nature and Environmental Technology Kanazawa University korean Institute of Geology and Mineralogy 3. Center for Chronological Research Nagoya University

This study aims to reveal Holocene environmental changes on the bases of the physical and chemical analyses of the sediment core obtained from Lake kliuvsgul in Mongolian Plateau and Lake Siling-co in Tibetan *** results of the Holocene sedimentary sequence in Borsog Bay of Lake khuvsgul shows that certain environmental shifts at about Little Ice Age and 3.5 ka BP;noticeable increases are detected in mineral grain size,whole grain size,mineral content and grain density during the periods when the organic matter content,biogenic silica content and diatom abundance *** sediment in Lake Siling-co indicates a comparatively large fluctuations in hydrological conditions at a water inflow for a short period at about 3000;000 a BP;and decreases in the water level at about 4000 a BP and 3500 a BP,when mineral fractions and whole sediments return to coarse grains,mineral content increased,and organic matter and biogenic silica *** results suggest the comparatively large hydrological changes in the inner Asia during the Late Holocene with a similar pattern of the humidity and aridity in the both lakes.

关键词： Asia Holocene sedimentary records in Inner Continental Asia

TLCI analysis on sediment of Lake Hovsgol

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

地球环境学报 2011年第1期 313-314页

作者： Inagaki A Hasebe N Ito k Endo N kashiwaya k Institute of Nature and Environmental Technology Kanazawa University

Luminescence dating observes the natural accumulated radiation damage caused by radioisotopes such as U and Th as the form of glow after stimulation by heating or *** luminescence is observed at various wavelength bands and their characteristics have been studied mainly on quartz and *** emission color of luminescence can be recorded easily by using thermoluminescence color image（TLCI） analysis method for samples artificially irradiated with *** et al（2009） investigated the validity of TLCI analysis for boring core samples from Lake Baikal（in Russia）,Lake khuvsgul（in Mongolia） and Byeokgolje（in South korea）.When TLCI analysis is applied to polymineral from lake sediments,the luminous mineral compositions of samples reflect of the regional characteristic and climate of the studied *** we combine the TLCI with other data,we would be able to obtain information of sample's source and the surrounding environment at the time of *** this study,HDP04 core sample from Lake Hovsgol was investigated to see color change of glow along *** the acquired TLCI fluctuation was compared with the data investigated by previous *** samples were etched with H2O2to remove organic matter that does not show any luminescence.A60Co gamma-ray source was used to irradiate samples at kyoto University Research Reactor *** the photograph of TLCI was taken under a constant temperature of 230 ℃.The used camera was normal single-lens reflex camera（Canon EOS kiss Digital N） with micro lens（Canon EF 50 mm f/2.5 Compact-Macro）.To analyze TLCI quantitatively,colored pixels of the photograph were picked up by the program built in this study and then converted to numerical *** on Ganzawa et al（2001）,color index was calculated from these numerical values and then were divided into five color *** from an aliquot vary and show poor reproductivity,however,the average results varied along depth reflecting characteri

关键词： Lake TLCI analysis on sediment of Lake Hovsgol

从Borsog湾khuvsgul湖的湖泊沉积物推得的蒙古北部全新世水文环境的变化（英文）

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

地球环境学报 2011年第3期2卷 457-461页

作者： ORkHONSELENGE A MINO k kashiwaya k kRIVONOGOV S YAMAMOTO T SAkAGUCHI A NAkAMURA T Institute of Nature&Environmental Technology Kanazawa University LLRL Institute of Nature&Environmental TechnologyKanazawa University Institute of Geology Geophysics & MineralogySB RAS Department of Earth&Planetary System Sciences Hiroshima University Center for Chronological Research Nagoya University

A 13-m long sediment core from Borsog Bay of Lake khuvsgul,northern Mongolia records hydro-environmental changes during the past 10000 years;three rapid environmental changes(ca.2700 a BP,ca.6000 a BP and ca.8000 a BP based on ^(14)C dates of organic carbon materials) are detected in depth profiles of sediment physical *** changes in the physical properties of the core(grain size,grain density and water content) also suggest three periods of large discharge from outside and three periods of stable input(200-500 cm,800-980 cm and 1050-1200 cm).The sedimentation rates in the stable period are 0.102 cm·a^(-1),0.085 cm·a^(-1) and 0.139 cm·a^(-1),*** periods of large discharge likely correspond to the intervals of the three rapid environmental changes,indicating that there were three rapid and high discharge periods related to melt water and/or heavy rainfall during the past 10000 years in this *** analytical results also show that the physical properties are valuable in reconstructing past hydro-geomorphological fluctuations in the lake-catchment system.

关键词： sedimentation rate hydro-geomorphology environmental change Holocene Lake khuvsgul Mongolia

Luminescence dating of bottom sediments from Lake Hovsgol,Mongolia(HDP-08)

在线全文

学校读者我要写书评

暂无评论

地球环境学报 2011年第1期 314-314页

作者： Ito k Hasebe N kashiwaya k Nakamura T Ganzawa Y Graduate School of Natural Science and Technology Kanazawa University Institute of Nature and Environmental Technology Kanazawa University Center for Chronological Research Nagoya UniversityFuro-choChikusa-kuNagoya 464-8602Japan Institute of Earth Science Hokkaido University of Education

To understand the past environmental change using geological archives（e.g.,core of sediments or ice）,establishing the reliable chronology is one of the most important key *** dating is a powerful mediod due to its applicability to quartz,which is common mineral found in various kinds of environment,and the datable age range being from present to 100 cal ka.A core of18 m in length were obtained in 2008 from Lake Hovsgol,Mongolia（HDP-08） for the purpose of reconstructing the climate-forcing environmental fluctuation in the central continent with high *** this study,optically stimulated luminescence（OSL） from quarts and red thermoluminescence（RTL） from carbonate were measured to estimate depositional ages the *** 16 samples were collected every 10 cm from the core using squire stainless tubes（1 cm × 1 cm） with the length of 4 *** surface part,which was exposed to light during core dividing procedures,was then removed in a dark *** chemical treatment to extract fine grained quarts,OSL were *** were measured on the bulk sediments based on the thermoluminescence colour images of particular components of *** was measured by MOSL-11 or MOSL-22 with x-ray source（MEDEC）.When the Des estimated from OSL and RTL are compared,they are identical for eleven samples within the error *** estimate annual dose,concentrations of radioisotopes(238U,234U,232Th and87Rb) were measured by laser ablation- inductively coupled plasma- mass spectrometry（LA-ICPMS）.Potassium concentration was measured by X-ray fluorescence spectrometry（XRF）.The OSL ages increase from（6.8 ± 3.7） ka to（72.4 ± 13.6） ka along with the depth,but are smaller than C *** may be caused by either or both of underestimation of water content in estimation of annual dose and overestimation of C ages due to reservoir effect.

关键词： Lake HDP-08 Luminescence dating of bottom sediments from Lake Hovsgol,Mongolia OSL

Aqueous-phase reforming of hydroxyacetone solution to bio-based H_(2)over supported Pt catalysts

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第4期9卷 777-788页

作者： A.k.k.Vikla k.koichumanova Songbo He k.Seshan Joint International Research Laboratory of Circular Carbon Nanjing Tech UniversityNanjing211816China Faculty of Science and Technology University of Twente7500 AE EnschedeThe Netherlands CoRe Pro 9723 BL GroningenThe Netherlands

Aqueous-phase reforming(APR)is an attractive process to produce bio-based hydrogen from waste biomass streams,during which the catalyst stability is often challenged due to the harsh reaction *** this work,three Pt-based catalysts supported on C,AlO(OH),and ZrO_(2)were investigated for the APR of hydroxyacetone solution in afixed bed reactor at 225℃and 35 *** them,the Pt/C catalyst showed the highest turnover frequency for H_(2)production(TOF of 8.9 molH_(2)molPt^(-1)min^(-1))and the longest catalyst *** the AlO(OH)and ZrO_(2)supported Pt catalysts,the side reactions consuming H_(2),formation of coke,and Pt sintering result in a low H_(2)production and the fast catalyst *** proposed reaction pathways suggest that a promising APR catalyst should reform all oxygenates in the aqueous phase,minimize the hydrogenation of the oxygenates,maximize the WGS reaction,and inhibit the condensation and coking reactions for maximizing the hydrogen yield and a stable catalytic performance.

关键词： APR Hydroxyacetone TOF Bio-based H_(2) Support effect

Climato-hydrogeomorphological fluctuations printed in lacustrine records in Lake Hvsgl,Mongolia

在线全文

学校读者我要写书评

暂无评论

地球环境学报 2011年第1期 315-315页

作者： kashiwaya k Nakagawa T Yumoto M Hasebe N Nakamura T kawai T Hdp&Ddp Members Institute of Nature and Environmental Technology Kanazawa University Center for Chronological Research Nagoya University Association of International Research Initiatives for Environmental Studies

Lacustrine sediment information(HDP04,HDP08 and HDP09) printed in Lake H(o|¨)vsg(o|¨)l,Northern Mongolia and the lake-catchment conditions reveal long-and short-term environmental changes in the lake-catchment *** in fluvial systems between the Holocene and the late Pleistocene have influenced sedimentary *** information suggests that there were often rapid mass inflows(debris flow,turbidity,etc.) from the catchments during the late *** glacial-interglacial cycle is most clearly presented by aridity(water level change):three Milankovitch parameters(precession,obliquity and eccentricity) are detected in long lacustrine information.A deep depression(cold stage comparable to glacial periods),corresponded to insolation minimum,is detected at about the MIS-5d in records,indicating that this region is highly sensitive to solar *** depression found during the MIS-11 interval,corresponded also to small insolation minimum,shows that the interval was not a simple prolonged interglacial period.

关键词： Lake Climato-hydrogeomorphological fluctuations printed in lacustrine records in Lake H l,Mongolia vsg

Direct scaling of residual displacements for bilinear and pinching oscillators

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2024年第1期23卷 129-149页

作者： Mohammad Saifullah Vinay k.Gupta Department of Civil Engineering Indian Institute of Technology KanpurKanpur 208016India

The estimation of residual displacements in a structure due to an anticipated earthquake event has increasingly become an important component of performance-based earthquake engineering because controlling these displacements plays an important role in ensuring cost-feasible or cost-effective repairs in a damaged structure after the *** attempt is made in this study to obtain statistical estimates of constant-ductility residual displacement spectra for bilinear and pinching oscillators with 5%initial damping,directly in terms of easily available seismological,site,and model *** of the available models for the bilinear and pinching oscillators are useful when design spectra for a seismic hazard at a site are not *** statistical estimates of a residual displacement spectrum are proposed in terms of earthquake magnitude,epicentral distance,site geology parameter,and three model parameters for a given set of ductility demand and a hysteretic energy capacity coefficient in the case of bilinear and pinching models,as well as for a given set of pinching parameters for displacement and strength at the breakpoint in the case of pinching model *** proposed scaling model is applicable to horizontal ground motions in the western *** earthquake magnitudes less than 7 or epicentral distances greater than 20 km.

关键词： residual displacement spectrum bilinear hysteresis model pinching hysteresis model nonlinear analysis scaling model

Analysis of the Oscillatory Flows of Multiple Shock Waves in a Constant Area Duct

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第3期33卷 794-806页

作者： k JAMES Jintu kIM Heuy Dong Department of Mechanical Engineering Andong National UniversityAndong36729Republic of Korea CAD-IT korea Co. Ltd.Seoul08591Republic of Korea

The oscillatory response of multiple shock waves to downstream perturbations in a supersonic flow is studied numerically in a rectangular *** shock waves are formed inside the duct at a shock Mach number of *** duct has an exit height of H,and the effect of duct resonance on multiple shock oscillations is investigated by attaching exit ducts of lengths 0H,50H,and *** downstream disturbance frequency varied from 10 Hz to 200 Hz to explore the oscillation characteristics of the multiple shock *** oscillatory response of shock waves under self-excited and forced oscillation conditions are analyzed in terms of wall static pressure,shock train leading-edge location,shock train length,and the size of the separation *** extent of the initial shock location increases with an increase in exit duct length for the self-excited oscillation *** analysis of the shock train leading edge and the spectral analysis of wall static pressure variations are *** variation in the shock train length is analyzed using the pressure ratio method for self-excited as well as forced *** RMS amplitude of the normalized shock train length(ζ_(ST))increases with an increase in the exit duct length for the self-excited oscillation *** the downstream perturbation frequency is increased,ζ_(ST)is decreased for exit duct *** all exit duct designs and downstream forcing frequencies,the size of the separation bubble grows and shrinks during the shock oscillations,demonstrating the dependence on duct resonance and forced oscillations.

关键词： shock train downstream disturbance supersonic flow shock wave boundary layer interaction duct resonance flow separation