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A tentative study for the prediction of the CME related geomagnetic storm intensity and its transit time

Science china(Technological sciences) 2005年第6期48卷 648-668页

作者： ZHAO Xinhua1,2.& FENG Xueshang1,3 1. SIGMA Weather Group, Key Laboratory of Space Weather, Center for Space Science and Applied Re-search, Chinese Academy of sciences, beijing 100080,{2. 2. Graduate school of the Chinese Academy of sciences, beijing 100039,{2. 3. school of Geophysics and Geoinformation Systems,{2. University of geosciences, beijing 100083,{2. SIGMA Weather Group Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Graduate school of the Chinese Academy of sciences Beijing China school of Geophysics and Geoinformation Systems China University of Geosciences Beijing China

Using 80 CME-ICME events during 1997.1―2.02.9, based on the eruptive source locations of CMEs and solar magnetic field observation at the photosphere, a current sheet magnetic coordinate (CMC) system is established in order to study the propagation of CME and its geoeffectiveness. In context of this coordinate system, the effect of the eruptive source location and the form of heliospheric current sheet (HCS) at the eruptive time of CME on the geomagnetic storm intensity caused by CME and the CME’s transit time at the earth is investigated in detail. Our preliminary conclusions are: 1) The geomagnetic disturbances caused by CMEs tend to have the so-called “same side-opposite side effect”, i.e. CMEs erupt from the same side of the HCS as the earth would be more likely to arrive at the earth and the geomagnetic disturbances associated with them tend to be of larger magnitude, while CMEs erupting from the opposite side would arrive at the earth with less probability and the corresponding geomagnetic disturbance magnitudes would be relatively weaker. 2. The angular separation between the earth and the HCS affect the corresponding disturbance intensity. That is, when our earth is located near the HCS, adverse space weather events occur most probably. 3) The erupting location of the CME and its nearby form of HCS will also affect its arrival time at the earth. According to these conclusions, in this context of CMC coordinate we arrive at new prediction method for estimating the geomagnetic storm intensity (Dstmin) caused by CMEs and their transit times. The application of the empirical model for 80 CME-ICME events shows that the relative error of Dst is within 30% for 59% events with Dstmin≤?50 nT, while the averaged absolute error of transit time is lower than 10 h for all events.

关键词： coronal mass ejections, current sheet magnetic coordinate system, geomagnetic storm intensity, transit time, prediction method.

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Dehydration melting of solid amphibolite at 2.0 GPa: Effects of time and temperature

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Science china earth {2. 2005年第8期48卷 1120-1133页

作者： ZHOU Wenge1, XIE Hongsen1, LIU Yonggang1, ZHENG Xiaogang1, ZHAO Zhidan2.& ZHOU Hui3 1. Laboratory of Material in the earth’s Interior, Institute of Geochemistry, Chinese Academy of sciences, Guiyang 550002.{2. 2. Department of Geology,{2. University of geosciences, beijing 100083,{2. 3. Department of Geology, Peking University, beijing 100871,{2. Laboratory of Material in the earth’s Interior Institute of Geochemistry Chinese Academy of Sciences Guiyang China Department of Geology China University of Geosciences Beijing China Department of Geology Peking University Beijing China

Two sets of dehydration-melting with a natural solid amphibolite, collected from North Himalayan structure zone, Tibet, have been carried out in multi-anvil apparatus at 2.0 GPa and 800―1000℃, for 12.2.0 h. One is keeping the pressure at 2.0 GPa and the annealing time of 12.h, changing the temperature (800―1000℃). The other is keeping the pressure at 2.0 GPa and temperature at 850℃, varying the annealing time (12.2.0 h). The products are inspected with microscope and electron probe. The results indicate that at 2.0 GPa, annealing time of 12.h, garnets, melts and clinopyroxenes occur in amphibolite gradually with increasing temperature and the chemical compositions of melt vary from tonalite to granodiorite, and then to tonalite. However, at 2.0 GPa and 850℃, with the annealing time increasing, the garnets, melts and cli-nopyroxenes also occur in amphibolite gradually and the chemical compositions of melt vary from tonalite to granodiorite. In both cases, melts interconnect with each other when the contents of melt are over the 5 vol.%. the viscosities of the melt produced in amphibolite at temperature higher than 850℃ are on a level with 104 Pa·s. The interconnected melt with such a viscosity may segregate from the source rock and form the magma over reasonable geological time. Therefore, it is believed that at the lower part of the overthickened crust, the tonlitic and grano-dioritic magma may be generated through the dehydration melting of amphibolite.

关键词： solid amphibolite, high pressure, high temperature, time, partial melting.

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Simulating the transfer and fate of hexachlorocyclohexane in recent 50 years in beijing, china

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Science china earth {2. 2005年第12期48卷 2203-2213页

作者： CAO Hongying1, LIANG Tao1 & TAO Shu2.1. Institute of Geographical sciences and Natural resources Research, Chinese Academy of sciences, beijing 100101, china 2. Laboratory for earth Surface Processes, Peking University, beijing 100871, china Institute of Geographical sciences and Natural resources Research Chinese Academy of Sciences Beijing China Laboratory for earth Surface Processes Peking University Beijing China

Taking beijing as a study area, a dynamic fugacity model was used to simulate the transfer and fate of technical HCHs according to the physic-chemical properties of the studying environment and HCH isomers. Dynamic changes of the transfer fluxes and concentrations of HCH isomers during 1952.2.03 were simulated and the model results suggest good agreement between the calculated and measured concentrations of HCH isomers. During 1952.1983, the average input and output amount of HCHs through agricultural application and degradation are 130 t and 150 t respectively. The dominant transfer processes of HCHs in the study area are air-soil deposition, soil erosion and soil-air diffusion, transfer fluxes of these processes are 80 t?a?1, 16 t?a?1 and 11 t?a?1, which account for 92. of total transfer fluxes of HCHs isomers. There were approximately 2.3t HCHs in all environmental compartments of the study area during this period and 97% of which existed in soil compartment. Air and water advection became the dominant input sources of HCHs after 1984 when the application of technical HCHs was prohib-ited, concentration of HCHs quickly descended to a quite low level in several years. Total amount of HCHs isomers remaining in the study area environment now is less than 5% that before 1983, and this percentage may descend to 0.5% after 2. years by prediction.

关键词： fugacity model, hexachlorocyclohexane, compartment, transfer flux, fate.

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Problems of Sequence Stratigraphy in china

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Journal of earth Science 2000年第3期19卷 10-20页

作者： Wang Hongzhen Faculty of earth sciences and Mineral {2., china University of geosciences, beijing 100083, china

A comprehensive study of outcrop sequence stratigraphy in china began in the early 1990s. The investigated strata range from Mesoproterozoic to Quaternary and the studied areas cover the three platforms and margins, the Southern Himalayas and the East china and South china seas. Problems of general concern in the sequence stratigraphy of china are discussed. These are: the hierarchy for sequence stratigraphy, the third order Sequence and eustasy, the chronostratigraphic boundaries and GSSP, and the International Stratigraphic Chart and the sequence chronostratigraphy of china. The average time interval of Mesosequence (2.-40 Ma) and of the Sequence (2.5 Ma) is suggested and the minor sequences below the Sequence are discussed. The time interval of the Sequence shows no evident decrease with time, but several epochs with remarkable short intervals occur in the Phanerozoic, which may represent a planetary behavior denoting the special development stages in earth’s evolution. Sea level change curves are given separately for the three platforms and the different regions. The Global Stratotype Section and Point (GSSP) concept and practice are discussed, and a comparison between the first appearance point of biozone and the first flooding surface in the Sequence is made for designation of the chronostratigraphic boundary. It is suggested that the chronostratigraphic boundaries might be set at the first flooding surface in the Sequence for easy recognition. The idea of sequence chronostratigraphy is recommended, and a comparison between the International Stratigraphic Chart and the sequence chronostratigraphy of china is made. The close relation between chronostratigraphy and sequence stratigraphy makes it possible for sequence stratigraphy to improve chronostratigraphic research. It is pointed out that multidisciplinary study in chronostratigraphy is necessary and should be promising and profitable.

关键词： sequence stratigraphy chronostratigraphy GSSP china.

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Three-point bending fracture characteristics of bulk metallic glasses

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Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 654-657页

作者： FAN ZhenJun, ZHENG ZhiYuan & JIAO ZengBao school of Materials sciences and Technology,{2. University of geosciences, beijing 100083,{2. school of Materials sciences and Technology China University of Geosciences Beijing China

This paper presents the SEM micrographs for the three-point bending fracture surfaces of Zr-based, Ce-based and Mg-based bulk metallic glasses (BMGs), which show the dimple structures in the three kinds of BMGs. The shapes of the giant plastic deformation domain on the fracture surface are similar but the sizes are different. The fracture toughness KC and the dimple structure size of the Zr-based BMG are both the largest, and those of the Mg-based BMG are the smallest. The fracture toughness KC and the dimple structure size of the Ce-based BMG are between those of the Zr-based and the Mg-based BMG. Through analyzing the data of different fracture toughnesses of the BMGs, we find that the plastic zone width follows w = (KC/σY)2.(6π).

关键词： metallic glass fracture surface tree-point bending

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Triassic Sequence Stratigraphy and Sea-Level Changes in Qomolongma Area, Southern Tibet, china: From Epicontinental Sea to Rift Basin

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Journal of earth Science 2000年第3期19卷 47-57页

作者： Shi Xiaoying Faculty of earth sciences and Land {2., china University of geosciences, beijing 100083, china

The Triassic in the Qomolongma area, southern Tibet, was deposited under an extensional tectonic setting from the Pangea supercontinent to continental rifting. From the Induan to Rhaetian, 12.depositional sequences (3rd order) have been recognized, which can be grouped into 5 sequence sets and in turn make up a well defined mesosequence (2.d order). Among the recognized marine transgressions, those at 2.0 Ma, 2.9 Ma, 2.1 Ma and 2.3 Ma respectively are particularly of significance and can be correlated widely across continents. The study shows that in Triassic the Qomolongma area experienced a sedimentary evolution from epicontinental sea to rift basin with the turning point at ca 2.8 Ma. During the early and middle epochs, the area was under epeiric sea, with carbonate ramp to mixed shoal environments predominant. In the late Carnian, the strong extension initiated listric faulting, thus resulting in rapid basement subsidence and the onset of a rift basin. From the late Norian to Rhaetian, it manifested as a rapid basin filling process in the area. Coupled with long term sea level fall, the excessive terrigenous influx led to the shift of environment from deep water prodelta to shore and finally to fluvial plain.

关键词： Triassic sequence stratigraphy sea level change cycles basin evolution southern Tibet.

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Compressive fracture characteristics of Zr-based bulk metallic glass

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Science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 823-827页

作者： FAN ZhenJun,ZHENG ZhiYuan & JIAO ZengBao school of Materials sciences and Technology,{2. University of geosciences,beijing 100083,{2. school of Materials sciences and Technology China University of Geosciences Beijing China

The compressive fracture characteristics of Zr-based bulk metallic glass under uniaxial compression tests are *** zigzag rheological behavior is observed in the compression stress-strain curves of amorphous *** room temperature the uniaxial compression fracture takes place along the plane which is at a 45-degree angle to the direction of the compressive *** microstructure of a typical fracture pattern is the vein network.A unique,finger-like vein pattern is found to exist at the fracture surface of Zr-based bulk metallic glass.

关键词： bulk metallic glass fracture surface compressive fracture

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Discovery of a pterodactylid pterosaur from the Yixian Formation of western Liaoning,china

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Chinese Science Bulletin 2001年第13期46卷 1112-1117页

作者： WANG Xiaolin & LU Junchang1. Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of sciences, beijing 100044,{2. 2. College of earth sciences and resources,{2. University of Geo-sciences, beijing 100083,{2. 3. Department of Geological sciences, Southern Methodist University, Dallas, TX 752.5, USA Institute of Vertebrate Paleontology Chinese Academy of Sciences Beijing 100044 China

A well-preserved pterosaur with nearly complete skull is described from the Lower Cretaceous Yixian Formation at Sihetun in western Liaoning. It is characterized by a low and long crestless skull, slender and pointed teeth, long metacarpal, nearly equal length of metatarsals I -III and short pedal digit V. It is referred to a new genus and species of the family Pterodactylidae: Haopterus gracilis gen. et sp. nov. This is the first pterosaur with a nearly complete skull from the Jehol Biota; it also represents the first non-controversial fossil record of Pterodactylidae in Asia. Haopterus is more derived than Pterodactylus from the Late Jurassic Solnhofen in Germany. This discovery extends the distribution of the family Pterodactylidae from Europe and Africa to Asia and its latest occurrence from the Late Jurassic to the Early Cretaceous. The discovery of Haopterus gracilis provides further evidence for the study of the originand radiation of the Jehol Biota; it also sheds new light on the evolution and

关键词： western Liaoning Early Cretaceous Yixian Formation Pterodactylidae.

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Implications of micro-compositions of garnet and biotite from high-grade meta-pelites

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Progress in Natural Science:Materials International 2006年第2期16卷 209-214页

作者： ZHOU Xiwen, WEI Chunjing, and ZHANG Shangkun ( Institute of Geology, CAGS, beijing 100037, china {2. of earth and Space sciences, Peking University, beijing 100871, china china University of Geo-sciences, beijing 100083, china) Institute of Geology CAGS Beijing 100037 China school of earth and Space {2. Peking University Beijing 100871 China china University of Geo-sciences Beijing 100083 China

Based on detailed studies on the compositional zoning of garnet and biotite in pelitic rocks from the Jingshan group of granulite facies in north Jiaodong, P-T pseudosections with isopleths of Fe/(Fe + Mg) in garnet and biotite were calculated in the KF-MASH system for two representative rocks of sillimanite-garnet-cordierite-biotite gneiss ( Vbi/ Vg>1 ) and sillimanite-garnet gneiss (Vbi/ Vg2. using the software THERMOCALC and the internally consistent thermodynamic dataset. With a comparison of the calculated Fe/(Fe+ Mg) values in garnet and biotite in the peak P-T fields constrained by peak mineral assemblages with the measured ones, it is concluded that the coarse garnet crystals with diffusion zoning from high grade meta-pelites can preserve their peak compositions even when they have experienced a cooling event, and that biotite crystals surrounded by fetsic minerals in biotite-rich rocks with Vbi/Vg> 1 can nearly preserve their peak compositions, and biotites in garnet-rich rocks with Vbi/Vg2.cannot preserve their peak compositions due to the influence of grain-boundary fluid.

关键词： high-grade meta-pelites THERMOCALC P-T pseudosection peak compositions of garnet and biotite.

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Petrology and tectonic significance of the early Mesozoic granulite xenoliths from the eastern Inner Mongolia, china

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Science china earth {2. 2011年第10期54卷 1484-1491页

作者： SHAO JiAn 1,2.& WEI ChunJing 1 1 The Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education school of earth and Space {2., Peking University, beijing 100871, china 2.Key Laboratory of Mineral resources, Chinese Academy of {2., beijing 10002., china The Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education school of earth and Space {2. Peking University Beijing China Key Laboratory of Mineral resources Chinese Academy of Sciences Beijing China

Granulite xenoliths are found in the early Mesozoic diorite intrusions from Chifeng and Ningcheng areas, eastern Inner Mongolia. The granulites are granoblastic and weakly gneissic with mineral assemblage of hypersthene, diopside, plagioclase and minor biotite, amphibole and ilmenite. Some samples contain the intergrowth composed of labradorite and vermicular hypersthene, and some coarse-grained plagioclases of andesine and labradorite composition occasionally develop bytownite rims with vermicular hypersthene, indicating a possible presence of garnet. Presence of blastogabbroic texture and hypersthene with diopside exsolution lamellae in some samples suggests that the protolith of the granulite is norite or gabbro. On the basis of metamorphic research and thermobaric calculation, the evolution of the granulite xenoliths is summarized into the following stages: (1) Isobaric cooling of underplated noritic or gabbroic magma in the lower crust led to the formation of probable garnet-bearing medium-high pressure granulite. (2. These higher pressure granulites were adiabatically uplifted to upper crust by dioritic magma and transformed to low pressure two-pyroxene granulite during an isothermal decompression. (3) The two-pyroxene granulite underwent retrograde metamorphism of different degrees during an isobaric cooling process as a result of crystallization and cooling of the dioritic magma. The pyroxenite-dominated cumulates and the medium-high pressure granulites may have rejuvenated the lower crust during the early Mesozoic.

关键词： early Mesozoic granulite xenolith lower crust North china Craton

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