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化工学报 2003年第Z1期54卷 62-66页

作者： GUO Guangjun,ZHANG Yigang and ZHAO Yajuan institute of geology and geophysics,{3. {4. of sciences beijing 100029,{3. institute of geology and geophysics Chinese Academy of Sciences Beijing 100029 China

Molecular dynamics simulations are performed to observe the evolutions of 512 and 51262 cage-like water clusters filled with or without a methane molecule immersed in bulk liquid water at 250 K and 23. K. The lifetimes of these clusters are calculated according to their Lindemann index δ (t) using the criteria of δ≥0.07. For both the filled and empty clusters, we find the dynamics of bulk water determines the lifetimes of cage-like water clusters, and that the lifetime of 512 62 cage-like cluster is the same as that of 512 cage-like cluster. Although the methane molecule indeed makes the filled cage-like cluster more stable than the empty one, the empty cage-like cluster still has chance to be long-lived compared with the filled clusters. These observations support the labile cluster hypothesis on the formation mechanisms of gas hydrates.

关键词： like in time that were MOLECULAR DYNAMICS SIMULATIONS OF FILLED AND EMPTY CAGE-LIKE WATER CLUSTERS IN LIQUID WATER AND THEIR SIGNIFICANCE TO GAS HYDRATE FORMATION MECHANISMS of cage GAS

Holocene grassland vegetation, climate and human impact in central eastern Inner Mongolia

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Science China Earth sciences 2005年第7期48卷 1025-1039页

作者： HUANG Fei1, Kealhofer Lisa2, XIONG Shangfa3.& HUANG Fengbao1 1. Nanjing institute of geology and Paleontology,chinese{3. of {4.,Nanjing 210008,China 2. Anthropology and Sociology Department,Santa Clara University,CA 95053.USA 3. institute of geology and geophysics,chinese{3. of {4.,beijing 100029,China Nanjing institute of geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China Anthropology and Sociology Department Santa Clara University CA 95053 United States institute of geology and Geoohysics Chinese Academy of Sciences Beijina 100029 China

Phytolith and pollen preserved in the Taipusi Banner paleosol profile, central eastern Inner Mongolia, provide evidence of Holocene grassland vegetation, climate and human impact. The combined phytolith and pollen records reveal a major change in vegetation composition about 5000 a BP. Before 5000 a BP, the vegetation was dominated by Aneurolepidium chinese-Stipa grandis grassland of C4.grasses. After 5000 a BP, C4.grasses rapidly retreated, indicating a shift to colder and more arid conditions. The gradual invasion of Stipa krylovii, Ag-ropyron desertorum, Ephedra, Chenopodiaceae and Caragana reveal the onset of grassland degeneration. Between 10000 and 8720 a BP, the Aneurolepidium chinese-Stipa grandis grassland included a small proportion of Artemisia shrub and Echionopos type plants, implying a strong winter monsoon and very weak summer monsoon. From 8720 to 7000 a BP, C4.grasses were common, indicating a strengthening of the summer monsoon. Between 7000 and 5000 a BP, the Holocene thermal maximum was evident, with a significant expansion of C4.grasses and the presence of some trees (such as Pinus and Betula, and so on) in or near the study site. From 4.00?000 a BP, a sandy grassland of Artemisia and Agropyron desertorum together with Aster-type taxa occurred. Precipitation amelioration took place between 3.00 and 2170 a BP, with a rapid development of Echinops type plants and a small expansion of C4.grasses. From 2170 a BP to present, human activities accelerated the process of grassland degeneration.

关键词： phytolith and pollen records grassland environment change human impact Holocene central eastern Inner Mongolia.

Crustal structure of Gondwana-and Yangtze-typed blocks:An example by wide-angle seismic profile from Menglian to Malong in western Yunnan

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Science China Earth sciences 2005年第11期48卷 1828-1836页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2, TENG Jiwen1, Lü Qingtian3. LI Jiliang1, SUN Shanxue1 & WANG Xinzheng1 1. institute of geology and geophysics,{3.,{4., China 2. institute of geophysics, chinese Seismological Bureau, beijing 100081, China 3. institute of Deposition Resource, chinese academy of Geological sciences, beijing 10003., China institute of geology and geophysics Chinese Academy of Sciences Beijing China institute of geophysics Chinese Seismological Bureau Beijing China institute of Deposition Resource Chinese Academy of Geological Sciences Beijing China

The wide-angle seismic profile between Menglian and Malong crosses the Baoshan block (Gondwana-typed), and Simao and southwestern Yangtze blocks (Yangtze-typed). By in-terpreting the wide-angle seismic data, we obtained the seismic crust/upper mantle structure of P-wave velocities together with the seismic reflections of these three blocks, Changning- Menglian and Mojiang suture zones among the mentioned three blocks. Our interpreting results demonstrate that the P-wave crustal velocity of Simao block is slower than that of Baoshan and southwestern Yangtze block and the crustal thickness gradually thickens from the Baoshan block, Simao to southwestern Yangtze block. Crustal reflection patterns of these three blocks have dis-tinct differences too. For the Gondwana-typed blocks, seismic reflections in the upper crust are well developed while in middle-lower crust they are very weak. The crustal reflections in the Yangtze block are very well developed. The crustal reflection patterns in Simao and southwest-ern Yangtze blocks are distinguishable. The average thickness of the crust in the studied area is about 4. km. And we make some discussions on the crustal thickening model of the three blocks in western Yunnan and tectonic setting of seismic developing and interaction of Gondwana and Yangtze blocks.

关键词： Gondwana blocks,Yangtze blocks,wide-angle profile,crustal structure,tectonic setting

δ^13.sc values of the loess-paleosol sequence in Dali area, Shaanxi Province, China, and paleoenvironmental implications

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chinese Science Bulletin 2003年第9期48卷 902-907页

作者： LI Yumei & LIU Dongsheng (LIU Tungsheng)institute of geology and geophysics,{3.,{4. (e-mail: liyrney@***) institute of geology and geophysics Chinese Academy of Sciences Beijing 100029 China

The carbon isotopic ratios of carbonate in the two profiles of the Dali area were analyzed and some new understandings on the influencing factors of the δ13.SC value of the loess-paleosol sequence and its paleoenvironmental implications were discussed preliminarily in this report. The 13.SC value of the Dali loess-paleosol sequence is synchronizing with the variance of magnetic susceptibility basically and the negative peaks of the δ13.SC curves are corresponding to the different developmental periods of the paleosol. It is believed that the intervention of the CO2 produced by plants will cause the decrease of the δ13.SC value, the amplitude of which may be relevant to the paleovegetation density and the ancient humidity. The relative biomass of C4.plants in the vegetation will affect the sublevel change of the δ13.SC. Low δ13.SC value by and large indicates the environmental conditions of the relatively abundant vegetation and humid climate. During the last 250000 years, the period with the sparsest vegetation and the most arid climate is the phase of the loess in L2 depositing and the period with the most abundant vegetation and the most humid climate is the last interglacial period. The δ13.SC curves of Dali also show that the High Temperature and Large Precipitation Event of the Qinghai-Tibetan Plateau during 4.-3. kaBP had affected the Central Shaanxi Plain with relatively humid climate, and had apparent influence on the local vegetation and humidity.

关键词：古环境大理地区黄土陕西湿润气候碳同位素植被高温天气

Forcing mechanism of the Pleistocene east Asian monsoon variations in a phase perspective

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Science China Earth sciences 2005年第10期48卷 1708-1717页

作者： TIAN Jun1,2, WANG Pinxian1, CHENG Xinrong1, WANG Rujian1 & SUN Xiangjun1,3.1. State Key Laboratory of Marine geology, Tongji University, Shanghai 200092, China 2. institute of geology and{3.,{4., beijing 100029, China 3. institute of Botany,{4., beijing 100093. China Tongji University chinese academy of sciences

The deep sea records from the ODP Sites 114. and 114. in the northern and southern South China Sea (SCS), including foraminiferal δ 18O and δ 13., Opal% and pollen percentage, reveal that the variations of the east Asian monsoon have been closely correlated with the variations of the Earth’s orbital parameters (eccentricity, obliquity and precession) and the global ice volume on orbital scale. All the monsoonal proxies show strong 100 ka, 4. ka and 23.ka cycles. Although G. ruber δ 13. of Site 114. is coherent with the ETP (ETP= normalized (eccentricity + obliquity-precession) at eccentricity, obliquity and precession bands, most of the coherent relationship focuses on the precession band, and the other monsoonal proxies are coherent with the ETP only at the precession band, which indicate that precession dominates the Pleistocene tropical climate changes. The phase relationship of the monsoonal proxies with the foraminiferal δ 18O implies that the global ice volume changes have played a significant role in modulating the east Asian monsoon climate, at least dominating the winter monsoon. This forcing mechanism of the east Asian monsoon is apparently different from that of the Indian ocean mon-soon. The variations of the east Asian monsoon at the precession band, at least that of the winter monsoon, have been controlled not only by the sensible heating but also by the latent heating of the surface water in the South China Sea.

关键词： South China Sea, ODP, east Asian monsoon, orbital forcing, global ice volume.

Sedimentary environment of the Dajin conglomerate in Tibet, age of foraminiferan assemblages and their tectonic significance

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Progress in Natural Science:Materials International 2005年第11期15卷 1014-1020页

作者： YAN Zhen, FANG Aimin, PAN Yusheng, LI Jiliang, LIU Xiaohan, YU Liangjun and ZHANG Binggao (Laboratory of Lithosphere Tectonic Evolution, institute of geology and geophysics,{3.,{4., China institute of Tibet Plateau Research,{3.,{4., China Nanjing institute of Paleontology,{3., Nanjing 210008, China) Laboratory of Lithosphere Tectonic Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China institute of Tibet Plateau Research Chinese Academy of Sciences Beijing 100029 China Nanjing institute of Paleontology Chinese Academy of Sciences Nanjing 210008 China

The Dajin conglomerate, which is one of the most important sedimentary successions of the Xigaze forearc basin in Tibet, China, consists of deep-shallow marine tuffaceous turbidites and clastic rocks bearing Nummulites, Assilina, Alveolina and Lock-hartia . These fossils are very similar to the foraminiferan in the Jialazi and Maila conglomerates, and those in Gangba and Dingri areas. They developed in the Eocene. By analyzing the spatial variation of Eocene sedimentary environments of Tibet Plateau and the foraminiferan in the Dajin conglomerate, we found that Eocene sedimentation should take place on both sides of the Yarlung Tsangpo suture, and the late Eocene tectonic uplifting should make the forearc basin expose out of the sea level and begin to receive nonmarine deposits.

关键词： Dajin conglomerate marine deposits Eocene foraminiferan Yarlang Tsangpo sutnre.

Orogen-parallel extension in Himalaya: Is it the indicator of collapse or the product in process of compressive uplift?

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chinese Science Bulletin 2000年第2期45卷 114-120页

作者： ZHANG Jinjiang, DING Lin, ZHONG Dalai & ZHOU Yong institute of geology and geophysics.{3..{4., China institute of geology and geophysics Chinese Academy of Sciences Beijing China

Extensional structures developed extensively in Himalaya with their strikes perpendicular to that of the orogenic belt. The studies of such structures in Qusum, Burang, Lhozhag, Nyalam and Yadong show that they represent an orogen-parallel extension. The basins produced by the extension experienced orokyn-perpendicular compression during their formation. The ages of the extension rang from 16 to 13.Ma and coincide with the intensive compressive stage in Southeastern Asia. Therefore, the extension is Syn-shortening and the dominate tectonic movement in Himalaya was compression and uplift during the extension. The extension was the partition of compressive deformation rather than the indicator for the collapse and falling of the Tibetan Plateau.

关键词： Himalayan orognic helt syn-shortening extension uplift

“Tali Glaciation” on Massif Diancang

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Science China Earth sciences 2007年第11期50卷 1685-1692页

作者： YANG JianQiang1, CUI ZhiJiu2, YI ChaoLu1, SUN JiMin3.& YANG LiRong3.1 institute of Tibetan Plateau Research, chinese academy of sciences, beijing 100085, China 2 College of Environmental{3., Peking University, beijing 100871, China 3.institute of geology and geophysics, chinese academy of sciences, beijing 100029, China institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China College of Environmental sciences Peking University Beijing China institute of geology and geophysics Chinese Academy of Sciences Beijing China

The term of ''Tali Glaciation'' is nominated from Massif Diancang in Yunnan Province. The confusing process of the term''s being put forward is confirmed through literature checking. Based on several times of field trip, the glacial landforms in this region are studied in detail, and the magnitude of the glaciation was determined. According to the numerical ages from TL, AIMS ^(14.C and OSL dating, the earliest glacial advance on Massif Diancang occurred at 3.—4. ka BP, followed by the advances at the last stage of the last glaciation, the late glacial and neoglations in turn, until glaciers vanished at 1.2—1.5 ca. a BP in this region. It can be concluded that glaciers were limited above 3.00 m a.s.l., and no glaciers existed on the lower part and adjacent mountains since the last glaciation.

关键词： Massif Diancang,Tali Glaciation,glacial landform,glaciation sequence,numerical dating

Effects of the grain size distribution on the temperature-dependent magnetic susceptibility of magnetite nanoparticles

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Science China Earth sciences 2010年第7期53卷 1071-1078页

作者： ZHAO XiangYu1,2 & LIU QingSong1 1 Paleomagnetism and Geochronology Laboratory (SKL-LE), institute of geology and geophysics,{3.,{4., China 2 Graduate University of{3., beijing 10004., China Paleomagnetism and Geochronology Laboratory (SKL-LE) Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

Magnetite is an important magnetic remanence carrier in natural samples and therefore is of great interest in paleo-, rock-, and environmental magnetism. The magnetic properties of magnetite depend on many factors, e.g., concentration and grain size distribution (GSD). In this study, we theoretically investigated the temperature-dependent susceptibility (TDS) of magnetite nanoparticles with a lognormal GSD. Results show that the TDS is affected highly by the GSD mainly in three aspects. Firstly, the unblocking process becomes smoother with the increase of distribution width, characterizing as a wider Hopkinson peak on the TDS curve. Secondly, the blocking temperature increases with the increase of the median diameter or/and the distribution width. Thirdly, the maximum susceptibility decreases with the increase of distribution width, and has a logarithmic function relation with the standard deviation of the distribution. As a case study, this model was further applied to the thermal products of the chinese loess/paleosol samples to determine the granulometry of newly-formed magnetite upon heating based on TDS curves. The results demonstrate the fidelity and feasibility of this method to determine the GSD of nano-sized magnetic particles.

关键词： Néel theory temperature dependence of susceptibility grain size distribution

Digital image analysis of palaeoenvironmental records and applications

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chinese Science Bulletin 2002年第23期47卷 1957-1963,2025-2026页

作者： SUN Donghuai1,2, LIU Yu2 & TAN Ming3.. South China Sea institute of Oceanology, chinese academy of sciences. Guangzhou 5103.1, China 2. State Key Laboratory of Loess and Quaternary geology, Earth Environmental institute, chinese academy of sciences, Xi’an 710075, China 3. institute of geology and geophysics, chinese academy of sciences, beijing 100029, China South China Sea institute of Oceanology Chinese Academy of Sciences Guangzhou China State Key Laboratory of Loess and Quaternary geology Earth Environmental Institute Chinese Academy of Sciences Xi’an China institute of geology and geophysics Chinese Academy of Sciences Beijing China

Environmental change signals in geological or biological records are commonly reflected on their reflecting or transmitting images. These environmental signals can be extracted through digital image analysis. The analysis principle involves section line selection, color value reading and calculating environmental proxy index along the section lines, layer identification, auto-chronology and investigation of structure evolution of growth bands. On detailed illustrations of the image technique, this note provides image analyzing procedures of coral, tree-ring and stalagmite records. The environmental implications of the proxy index from image analysis are accordingly given through application demonstration of the image technique.

关键词： digital image environmental records.