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Experimental study of the metamorphic reaction involving melt under high temperature and high pressure

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Chinese Science Bulletin 1998年第3期43卷 249-253页

作者： Fulai Liu Qihan Shen Yuansheng Geng Xuechun Xu Rui Ma Chinese Acad Geosci Inst Geol Beijing 100037 Peoples R China Changchun geol coll Open Lab Changchun 130021 Peoples R China

High P_T experiment with natural massive rock sample of garnet biotite plagioclase gneiss indicates that the metamorphic reaction involving melt (reaction between relic mineral phase and melt) is the most important re... 详细信息

关键词： metamorphic reaction involving melt natural massive rock garnet biotite plagioclase gneiss high_temperature and high_pressure experiment.

Discovery of fossil monocotyledons from Yixian Formation, western Liaoning

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Chinese Science Bulletin 1998年第3期43卷 230-233页

作者： Zhengyao Cao Shunqing Wu Ping’an Zhang Jieru Li Chinese Acad Sci Nanjing Inst Geol & Palaeontol Nanjing 210008 Peoples R China Fuxin Mineral coll Fuxin 123000 Peoples R China Reg geol Survey Team Liaoning Prov Dalian 116100 Peoples R China

This is the first reports of a few fossil monocotyledons, including \%Liaoxia chenii\% gen. et sp. nov. (belonging to Cyperaceae), \%Eragrosites changii\% gen. et sp. nov. (Gramineae) and a monocotyledonous leaf_shoot, obtained from the Late Jurassic Yixian Formation of western Liaoning Province, NE China. These fossils are the oldest known angiosperms in the world. It may be inferred that the earliest angiosperms probably appeared even earlier than the Late Jurassic.

关键词： western Liaoning Late Jurassic Yixian Formation monocotyledon.

Landscape eco-environment risk assessment of highway in arid area of Xinjiang,China

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Journal of Arid Land 2010年第1期2卷 20-25页

作者： Qian, YiBing Zhou, HuaRong Wu, ZhaoNing Chinese Acad Sci Xinjiang Inst Ecol & Geog Urumqi 830011 Peoples R China Xinjiang Univ Coll Geol & Explorat Engn Urumqi 830046 Peoples R China

With the aid of analyses to landscape ecology in the highway region of the arid area in Xinjiang of China, vegetation type, soil type and land-use type were ascertained as environmental factors of highway landscape ecosystem fragility, and seasonal flood, blown-wind sand and alkali-salinization as disaster factors of highway engineering. All items of these factors constitute an objective hierarchy of evaluating landscape ecosystem risk of the highway region in the arid area. The weighted values of the items were determined according to the number of occupied area or length by them against each unit. The area or length was interpreted with the aids of GIS technology and gained by measuring in the highway reconnaissance. The results of the eco-environmental risk assessment of G315 Yitunbulake-Qiemo section in Xinjiang shows that eight units of landscape ecology can be sorted into four categories according to the differences of the fragility indices (Σxiwi) and the disaster indices (Σyiwj).

关键词： highway of arid area landscape eco-environment risk assessment

General regularity of dynamic responses of slopes under dynamic input

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Science China(Technological Sciences) 2003年第Z1期46卷 120-132页

作者： QI Shengwen, WU Faquan & SUN Jinzhong Institute of geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China college of Engineering Technique, China University of Geosciences, Beijing 100083, China Chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China China Univ Geosci Coll Engn Techn Beijing 100083 Peoples R China

Through lots of numerical simulations with FLAC3D, dynamic responses of slopes are comprehensively studied in this paper and the general regularities of the isoline of the coefficient of the displacement, velocity and acceleration of the slope section are reached. Given a certain material slope, if the height of the slope is less than a certain value, the displacement, velocity and acceleration linearly enlarge with elevation in the vertical direction; if the height of the slope surpasses the certain value, the displacement,velocity and acceleration do not linearly enlarge with elevation any more, on the other hand, they fluctuate with a certain rhythm. At the same time, the rhythm appears in the horizontal direction, and the displacement, velocity and acceleration of the slope surface enlarge near the slope surface. The distribution form of the isoline of the coefficient of displacement, velocity and acceleration in the section of the slope is remarkably affected by the slope angle. In the certain area near the slope surface, the isoline of displacement,velocity and acceleration is parallel to the surface of the slope; in the mean time the strike direction of the extremum area is parallel to the surface of the slope, too. The charts of the slope dynamic responses can be depicted with two indexes, one is the strike direction of the isoline, and the other is the number of the rhythm extremum area of the direction parallel to the surface of the slope.

关键词： slope, dynamic response, regularity, rhythm.

Assessing Post-Storm Forest Dynamics in the Pyrenees Using High-Resolution LIDAR Data and Aerial Photographs

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Journal of Mountain Science 2015年第4期12卷 841-853页

作者： ángela BLáZQUEZ-CASADO José R.GONZáLEZ-OLABARRIA Santiago MARTíN-ALCóN Ariadna JUST Mariló CABRé Lluís coll Forest Sciences Center of Catalonia (CTFC) Institut Cartogràfic i geològic de Catalunya (ICGC)

We evaluated how historical storm events have shaped the current forest landscape in three Pyrenean subalpine forests(NE Spain).For this purpose we related forest damage estimations obtained from multi-temporal aerial photographic comparisons to the current forest typology generated from airborne Li DAR data, and we examined the role of past natural disturbance on the current spatial distribution of forest structural *** found six forest structural types in the landscape: early regeneration(T1 and T2), young even-aged stands(T3), uneven-aged stands(T4) and adult stands(T5and T6).All of the types were related to the timing and severity of past storms, with early-regeneration structures being found in areas markedly affected in recent times, and adult stands predominating in those areas that had suffered lowest damage levels within the study *** general, landscapes where high or medium levels of damage were recurrent also presented higher levels of spatial heterogeneity,whereas the opposite pattern was found in the less markedly affected landscape, characterized by thepresence of large regular *** results show the critical role that storm regimes in terms of timing and severity of past storms can play in shaping current forest structure and future dynamics in subalpine *** knowledge gained could be used to help define alternative forest management strategies oriented toward the enhancement of landscape heterogeneity as a measure to face future environmental uncertainty.

关键词：森林景观风暴动态评价雷达数据高分辨率亚高山森林照片航拍

Spatial heterogeneity for grain size distribution of eolian sand soil on longitudinal dunes in the southern Gurbantunggut Desert

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Journal of Arid Land 2009年第1期1卷 26-33页

作者： Qian, YiBing Wu, ZhaoNing Yang, HaiFeng Jiang, Chao Chinese Acad Sci Xinjiang Inst Ecol & Geog Urumqi 830011 Peoples R China Xinjiang Univ Coll Geol & Explorat Engn Urumqi 830046 Peoples R China Chinese Acad Sci Grad Sch Beijing 100039 Peoples R China

The grain size composition, distribution characteristics and spatial variation of eolian sand soil on distinct positions across two longitudinal dunes and interdune areas were studied by means of conventional grain size analysis and geostatistical methods. In the study, 184 samples of eolian sand soil from the 0-30cm layer were systemically collected and measured from two longitudinal dunes and interdunes in the southern Gurbantunggut Desert. The results show that the dominant grain sizes are fine and very fine sands, and the differences of grain size compositions between the distinct geomorphologic positions are significant. The contents of clay and silt are highest on the interdune areas and lowest on the crests, and higher on the leeward slopes than on the windward slopes. The contents of very fine and fine sands are highest on the windward slopes and lowest on the crests. The contents of medium, coarse and very coarse sands are lowest on the interdune lands, and highest on the crests, and are identical on the two slopes. The coarser sizes (phi(1)) and mean sizes (Mz) for eolian sand soil all have a varying tendency from fine to coarse sizes with interdune area -> leeward slope -> windward slope -> crest, and the sorting (sigma) are poorly to well sorted. The results of geostatistical analysis reveal that phi(1), Mz and a values are moderately to strongly spatially autocorrelated. The values of the spatially correlated ranges are phi(1) < sigma < Mz. The spatial variation for these grain size parameters is significant across the longitudinal dune landscape. From the crests towards the bottom of the slope, there is a varying gradient of zonal distribution, and the gradient values on the leeward slopes are larger than sites on the windward slopes.

关键词： grain size distribution spatial variation geostatistical analysis longitudinal dune the southern Gurbantunggut Desert

TIMS U-series ages of speleothems from the Tangshan caves, Nanjing

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Chinese Science Bulletin 1999年第21期44卷 1987-1991页

作者： Yongjin Wang Cheng Hai Conglun Luo Yingfei Xia Jiangying Wu Jun Chen Nanjing Normal Univ Coll Geog Sci Nanjing 210097 Peoples R China Univ Minnesota Dept Geol & Geophys Minnesota Isotope Lab Minneapolis MN 55455 USA Nanjing Univ Dept Geosci Nanjing 210093 Peoples R China

U-series ages of a set of speleothem samples from the two caves near Tangshan Town, Nanjing, determined by thermal ionization mass spectrometry (TIMS), range from older than 500 KaBP to around 20 kaBP. These dated speleothems with unequivocal stratigraphic layers in cave sediments provide basic data to establish a geochronologic sequence for the

关键词： speleothem U-series age Homo erectus Nanjing.

Bioptical microcycles of laminated speleothems from China and their chronological significance

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Chinese Science Bulletin 1999年第17期44卷 1604-1607页

作者： Ming Tan Xiaoguang Qin Linmei Shen Xianfeng Wang Yongjin Wang Tieying Li Linhua Song Laihong Wang Dongsheng Liu Chinese Acad Sci Inst Geol Lab Speleothem & Paleoclimatol Beijing 100029 Peoples R China Benxi Scen Spots Res Adm Bur Benxi 117100 Peoples R China Nanjing Normal Univ Coll Geog Nanjing 210097 Peoples R China Beijing geol Survey Inst Beijing 102206 Peoples R China Chinese Acad Sci Inst Geog Beijing 100101 Peoples R China Zhejiang Yaolin Cave Tonglu 311515 Peoples R China

Interfaces of microlayers, in most stalagmites from China, consist of opaque and organic materials. Observed with microscope, the interfaces seem dark under transmitted light and luminiferous under reflected fluorescent light. Stalagmites in which the two optical characters are unified spatially would be most suitable for cross-dating use, and can play an important role in the study on speleochronology and speleoclimatology.

关键词： natural clock stalagmite bioptical microlayer cross dating.