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Controlled analogue experiments on propagation of seismic electromagnetic signals

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Science Bulletin 2005年第17期 142-147页

作者： HUANG Qinghua Computational Geodynamics Laboratory, Department of Geophysics, school of earth and space sciences, peking university, beijing 100871, china

This study presented a method of laboratory analogue experiments based on a geographical scaling model and a waveguide model to investigate the characteristics of the propagation of seismic electromagnetic signals in the crust and the atmosphere. Some controlled experiments were done to evaluate the possible influence on the experimental results from the background electromagnetic field, geo-graphical conditions, boundary effects, the source of elec-tromagnetic signals (position, magnitude, and frequency), and media conductivity. The reliability and the extensibility of the above analogue experimental method were also inves-tigated. This study indicated that such kind of analogue ex-perimental method provided an intuitionistic way of studying the propagation of seismic electromagnetic signals, which is one of the most difficult research topics in seismo-electro- magnetism.

关键词： propagation of seismic electromagnetic signals seismo-electromagnetism waveguide model analogue experiments.

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

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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, china 2. Graduate school of the Chinese Academy of sciences, beijing 100039, china 3. school of Geophysics and Geoinformation Systems, china university of Geosciences, beijing 100083, china 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―2002.9, 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.

Mantle xenoliths from Late Cretaceous basalt in eastern Shandong Province: New constraint on the timing of lithospheric thinning in eastern china

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Chinese Science Bulletin 2003年第19期48卷 2139-2144页

作者： YAN Jun, CHEN Jiangfeng, XIE Zhi & ZHOU Taixi school of earth and space sciences, university of Science and Technology of china, Hefei 230026, china school of earth and space sciences University of Science and Technology of China Hefei China

The age of the alkali basalt from Daxizhuang in Jiaozhou, eastern Shandong, was determined to be 73.5±0.3 Ma by 40Ar-39Ar technique. The basalt gave high eNd(t) values of +7.5 and +7.6, suggesting that the primitive magma was derived from depleted asthenospheric mantle with a formation depth of about 65—95 km. Spinel-lherzolite xenoliths have been discovered in the basalt. The Fo values of olivine from the xenoliths range from 88 to 89. The estimated equilibrium P-T conditions of spinel-lherzolite xenoliths are about 2.0 GPa and 1010—1140℃, suggesting an equilibrium depth of about 65 km. Geochemical characteristics of the Late Mesozoic (125—115 Ma) mantle-derived rocks in Shandong Province suggest an enriched lithospheric mantle along the southern margin of the North china block. However, geochemical characteristics of the Late Cretaceous basalts in Daxizhuang and the equilibrium P-T condition estimated from the xenoliths suggest that the lithosphere at 73 Ma ago was as thick as that of the Cenozoic in the region. Additionally, the xenoliths are rich in basaltic-component, suggesting a derivation from a newly-formed lithosphere. Therefor, lithospheric thinning took place at a time interval between about 120 and 73 Ma along the southern margin of the North china block.

关键词：覆盖捕虏岩白垩纪玄武岩山东东部地区岩石圈稀释化 ^40Ar-^39Ar技术

Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

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Science china earth sciences 2005年第10期48卷 1672-1677页

作者： YANG Gang1,2, DU Andao1, LU Jiren3, QU Wenjun1 & CHEN Jiangfeng2 1. National Research Center of Geoanalysis, beijing 100037, china 2. Laboratory for earth Material Cycling, school of earth and space sciences, university of Science and Technology of china, Hefei 230026, china 3. Institute of Mineral Resource, Chinese Academy of Geological sciences, beijing 100037, china National Research Center of Geoanalysis university of Science and Technology of china Chinese Academy of Geological sciences

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 833 ± 35 Ma, initial 187Os/188Os ratio of 0.279 ± 0.018 (MSWD = 1.7) and γOs = 130 ± 15 is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 827 ± 8 Ma (n=5, MSWD = 4.3). The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 10%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, ICP-MS.

Syntheses, structures and magnetic properties of a family of one-dimensional M(Ⅱ)-lanthanide(Ⅲ) (M = Ni(Ⅱ) and Zn(Ⅱ)) coordination polymers

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Science china Chemistry 2007年第3期50卷 308-317页

作者： ZHANG Wen, ZHAO Fei, LIU Tao & GAO Song beijing National Laboratory for Molecular sciences, State Key Laboratory of Rare earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, peking university, beijing 100871, china beijing National Laboratory for Molecular sciences State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing China

A series of 1D nickel(II)/zinc(II)-lanthanide(III) coordination polymers, [M(μ-L)2Ln(NO3)3]n·solvents (HL = bis(2-pyridylcarbonyl)amine; M = Ni, Ln = Gd (1·NiGd), Tb (2·NiTb), Dy (3·NiDy), Ho (4·NiHo), Y (5·NiY); M = Zn, Ln = Gd (6·ZnGd), Tb (7·ZnTb), Dy (8·ZnDy), Ho (9·ZnHo); solvents = H2O or H2O-ethanol), was synthesized and characterized. All of the complexes are isostructural at 293 K and crystallize in the orthorhombic space group Fddd. Magnetic measurements were performed on 1―9, where weak ferromagnetic interaction is found in 1·NiGd, ferromagnetic interaction in 2·NiTb and 3·NiDy, and antiferromagnetic interaction in 4·NiHo. A remarkable dc magnetic field dependence of ac susceptibilities was found in this series of complexes.

关键词： nickel lanthanide 3d-4f coordination polymer magnetic property

Neoproterozoic magmatic activity and global change

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Chinese Science Bulletin 2003年第16期48卷 1639-1656页

作者： ZHENG Yongfei school of earth and space sciences, university of Science and Technol-ogy of china, Hefei 230026, china (e-mail: yfzheng@***) school of earth and space sciences University of Science and Technology of China Hefei China

Neoproterozoic is a very important time in the history of the earth, during which occurred supercontinent breakup, low-latitude glaciation, and biotic diversification. These concern a series of interdisciplinary studies involving ancient plate motion, climate change and life evolution, re-sulting in many forefront topics of general interest in the earth sciences. These include exact ages bracketing the Cryogenian System and glaciations, initial age and lasted duration of supercontinent breakup, dynamic reconstruction of china continents in supercontinental configurations, the nature of rift magmatism and extent of hydrothermal altera-tion, paleoclimatic implication of water-rock interaction and low-18O magmatism, and relationship between superconti-nental evolution and global change. A number of outstanding advances in the above aspects have being made by Chinese scientists, leaving many important issues to be resolved: (1) did the Cryogenian start at either 800 to 820 Ma or 760 to 780 Ma? (2) was South china in the supercontinental con-figuration located in either southeast to Australia or north to India? (3) are Paleoproterozoic to Archean ages of crustal rocks a valid parameter in distinguishing North china from South china? Available observations suggest that Neopro-terozoic mantle superwelling occurred as conspicuous mag-matism in South china but as cryptical magmatism in North china. Mid-Neoproterozoic mantle superplume event and its derived rift-magmatism would not only result in the supercontinental demise, but also play a very important role in the generation and evolution of the snowball earth event by initiating the global glaciation, causing the local degla-ciation and terminating the snowball earth event.

关键词：原生代大陆断裂低纬度地区生物多样性板块运动气候变化生物进化大陆构架全球变化冰川

Framework and development of digital china

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Science china(Technological sciences) 2008年第S1期51卷 1-5页

作者： WU Lun & TONG QingXi Institute of Remote Sensing and Geographical Information Systems,peking university,beijing 100871,china Institute of Remote Sensing and Geographical Information Systems Peking University Beijing China

Digital china (DC) has recently drawn much attention. It is a strategic project for china in response to the challenge of sustainable development of population,re-source,and environment. Intending to establish the national information infra-structure (NⅡ),the DC project forms a solid foundation for Chinese informatization. In such an NⅡ,multi-sourced spatial data are integrated. They focus on various themes and have different space and time features. Based on the NⅡ,numerous applications and services can be developed so that spatial information will benefit everyone. Since lots of organizations,such as governments,universities,and en-terprises,are involved in the implementation of DC,the DC project will significantly prompt the relevant scientific research as well as economic progress in china.

关键词： Digital earth Digital china spatial information sciences and technology

Multipliers and Herz type spaces

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Science china Mathematics 2008年第10期51卷 1919-1936页

作者： LU ShanZhen school of Mathematical sciences, beijing Normal university, beijing 100875, china school of Mathematical sciences Beijing Normal University Beijing China

Hrmander condition for boundedness of multiplier operators will be replaced by a weaker condition described by certain weighted or non-weighted Herz spaces. Some results on boundedness of multiplier operators are then established. As direct corollaries of main theorems in this paper, several celebrated results on boundedness of multiplier operators will be improved or deduced.

关键词： multiplier Herz space Herz type Hardy space 42B15 42B30 42B35

Effects of abnormally high heat stress on petroleum in reservoir——An example from the Tazhong 18 Well in the Tarim Basin

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Science china earth sciences 2008年第4期51卷 515-527页

作者： ZHU DongYa1, JIN ZhiJun1, HU WenXuan2 & ZHANG XueFeng3 1 Petroleum Exploration and Production Institute, china Petroleum & Chemical Corporation, beijing 100083, china 2 Department of earth sciences, Nanjing university, Nanjing 210093, china 3 school of Resource and Information, china university of Petroleum, beijing 102249, china Petroleum Exploration and Production Institute China Petroleum & Chemical Corporation Beijing China Department of earth sciences Nanjing University Nanjing China school of Resource and Information China University of Petroleum Beijing China

An igneous intrusion of 94m thick was discovered intruding into the Silurian sandstone from Tazhong 18 Well. The petroleum previously preserved in the Silurian sandstone reservoir was altered into black carbonaceous bitumen by abnormally high heat stress induced by the igneous intrusion. The reflec-tance of the carbonaceous bitumen reaches as high as 3.54%, indicating that the bitumen had evolved into a high thermal evolution level. Similar to the Silurian samples from the neighboring Tazhong 11, Tazhong 12, Tazhong 45 and Tazhong 47 wells, the distribution of C27, C28 and C29 steranes of the car-bonaceous bitumen is still "V" -shaped and can still be employed as an efficient parameter in oil source correlation. The "V" -shaped distribution indicates that the hydrocarbons from the Tazhong 18 and the neighboring wells were all generated from the Middle-Upper Ordovician hydrocarbon source rocks. However, the oil source correlation parameters associated with and terpanes had been changed greatly by the high heat stress and can no longer be used in oil source correlation. The δ 13C values of the pe-troleum from the neighboring wells are between -32.53‰ and -33.37‰, coincident with those of the Paleozoic marine petroleum in the Tarim Basin. However, the δ 13C values of the carbonaceous bitumen from the Tazhong 18 Well are between -27.18‰ and -29.26‰, isotopically much heavier than the pe-troleum from the neighboring wells. The content of light hydrocarbons (nC14-nC20) of the saturated hydrocarbon fraction in the carbonaceous bitumen is extremely higher than the content of heavy hy-drocarbons. The light/heavy hydrocarbon ratios (ΣnC21-/ΣnC22+) are between 4.56 and 39.17. In the saturated fraction, the even numbered hydrocarbons are predominant to the odd numbered, and the OEP (Odd to Even Predominance) values are between 0.22 and 0.49. However, the content of light hy-drocarbons in the petroleum from the neighboring wells is relatively low and the content of the even numb

关键词： Tarim Basin igneous intrusive abnormally high heat stress bitumen carbon isotope PAH