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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 {2., beijing 100080, China 2. graduate school of the chinese academy of {2., beijing 100039, China 3. school of Geophysics and Geoinformation Systems, China University of Geo{2., beijing 100083, China 1. SIGMA Weather Group Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. graduate school of the {2. academy of sciences 100039 Beijing China 3. school of Geophysics and Geoinformation Systems China University of Geosciences 100083 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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Assessment of soil erosion and sediment delivery ratio using remote sensing and GIS:a case study of upstream Chaobaihe River catchment, north China

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International Journal of Sediment Research 2008年第2期23卷 167-173页

作者： Weifeng ZHOU1 and Bingfang WU2.1 Doctor candidate,graduate school of the {2. academy of sciences(CAS),beijing 100039,China 2.Prof.,Institute of Remote Sensing Applications,{2. academy of sciences(CAS),beijing 100101,China [a]Doctor candidate graduate school of the {2. academy of sciences(CAS) beijing 100039 China [b]Prof. Institute of Remote Sensing Applications chinese academy of {2.(CAS) beijing 100101 China

Soil erosion in catchment areas reduces soil productivity and causes a loss of reservoir *** parametric models have been developed to predict soil erosion at drainage basins,hill slopes and field *** well-known Universal Soil Loss Equation(USLE) represents a standardized *** reservoir,which sits on Chaobaihe River,is the main surface source of drinking water for beijing,the capital of *** and soil loss are the main reasons for sediment to enter a *** yield is assessed using a version of the universal soil loss equation modified by chinese *** year 2.01 and 2.02.data for factors in the equation are obtained from remote sensing or collected to form an analysis *** factors are computed and mapped using Geographic Information System *** on the complex database,the modified model is *** pixel-based computing the sediment yield per hydrological unit is *** model does not consider sediment deposition occurring on *** soil loss is often higher than the sum of those measured at catchment *** sediment delivery ratio(SDR) per hydrological unit is also *** study analyzes the main contributions of sediment yields on sub-basins of the Chaobaihe River to the Miyun Reservoir,and discusses the possible reasons for the difference between SDRs in 2.01 and 2.02.at different *** result shows that in the upper basin of the Miyun Reservoir,in 2.01 the area of erosion that could be neglected was 8,2.2.76 km2.the area of low erosion 3,2.9.59 km2.the area of moderate erosion 3,400.97 km2.the area of high erosion 436.89 km2.the area of strong erosion 52.19 km2.and the area of severe erosion 3.13 *** highest soil loss was 70,353 t/*** in Fengning County in 2.01,followed by 64,418 t/*** by Chicheng County in *** SDR in 2.02.was lower than that in *** main reasons are the decreasing rainfall erosivity and total runoff.

关键词： Modified USLE Gross erosion Sediment delivery ratio

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Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough

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中国科学：地球科学英文版 2006年第4期49卷 375-383页

作者： HUANG Peng1,2. LI Anchun1, HU Ningjing2.3, FU Yongtao1& MA Zhibang4 1. Institute of Oceanology, chinese academy of {2., Qingdao 2.6071, China 2. graduate school of the chinese academy of {2., beijing 100039, China 3. Institute of Soil Science, chinese academy of {2., Nanjing 2.0008, China 4. Institute of Geology and Geophysics, chinese academy of {2., beijing 10002., China 1. Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China 2. graduate school of the {2. academy of sciences Beijing 100039 China 3. Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China 4. Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Volcanic rocks from the northern and middle Okinawa Trough were dated by ura- nium-series dating method. Differential fractions using magnetic procedure were designed to separate samples. New report on the ages and isotopic data of rocks in the northern trough (especially black pumice) was discussed. Based on the uranium dates and Sr-Nd isotopic ratio, magmatic evolution process of the Okinawa Trough was noted. Firstly, there have been wide silicic volcanic activities in the Okinawa Trough from late Pleistocene to present, and the volcanic rocks can be divided into three subgroups. Secondly, magma generally came from PREMA source area under the Okinawa Trough. Magmatic evolution in the northern trough was similar to the middle, but different to the south. Finally, volcanic activities indicated that opening of the southern Okinawa Trough did not happen due to the collision between Luson Arc and Eurasian Plate until the early Pleistocene.

关键词： Okinawa Trough, black pumice, uranium-series dating, Sr-Nd isotopic ratio, magmatic evolution.

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Improved K-means Algorithm for Manufacturing Process Anomaly Detection and Recognition

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武汉理工大学学报 2006年第S3期28卷 1036-1041页

作者： ZHOU Xiaomin~(1,2. PENG Wei~1 SHI Haibo~1 (1.Shenyang Institution of Automation chinese academy of {2.,Shenyang 110016,China, 2.graduate school,chinese academy of {2.,beijing 100039,China) Shenyang Institution of Automation chinese academy of {2. Shenyang 110016China graduate school Chinese Academy of SciencesBeijing 100039China Shenyang Institution of Automation chinese academy of {2. Shenyang 110016China

Anomaly detection and recognition are of prime importance in process *** are usually rare,and, therefore,predicting them is *** this paper,a new greedy initialization method for the K-means algorithm is proposed to improve traditional K-means clustering *** new initialization method tries to choose suitable initial points,which are well separated and have the potential to form high-quality *** on the clustering result of historical disqualification product data in manufacturing process which generated by the Improved-K-means algorithm,a prediction model which is used to detect and recognize the abnormal trend of the quality problems is *** simple and robust alarm-system architecture for predicting incoming faults realizes the transition of quality problems from diagnosis afterward to prevention beforehand *** the end,the alarm model was applied for prediction and avoidance of gear-wheel assembly faults at a gear-plant.

关键词： data mining clustering quality management anomaly detection and recognition

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Teleconnection between the Indian summer monsoon onset and the Meiyu over the Yangtze River Valley

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Science China Earth sciences 2008年第7期51卷 1021-1035页

作者： LIU YunYun1,2.3 & DING YiHui2.1 chinese academy of Meteorological {2., beijing 100081, China 2.National Climate Center, beijing 100081, China 3 graduate University of chinese academy of {2., beijing 100049, China 1. chinese academy of Meteorological {2. Beijing 100081 China 2. National Climate Center Beijing 100081 China 3. graduate University of chinese {2. of sciences Beijing 100049 China

Based on the Indian and chinese precipitation data and the NCEP-NCAR reanalysis circulation data, the relationship between the Indian summer monsoon (ISM) onset and the Meiyu over the Yangtze River Valley has been discussed by the methods of correlation analysis and composite analysis. The results show that the date of ISM onset over Kerala in the southwestern coast of the Indian Peninsula is about two weeks earlier than the beginning of the Meiyu over the Yangtze River Valley. After the outbreak of ISM, the teleconnection mode sets up from the western coast of India via the Bay of Bengal (BOB) to the Yangtze River Valley and southern Japan. It is different both in time and space from the telecon- nection mode which is from the northwest of India via the Tibetan Plateau to northern China. The for- mer mode is defined as the "south" teleconnection of the Asian summer monsoon, forming in the pe- riod of ISM onset; while the latter mode is called the "north" teleconnection, mainly occurring in the Asian monsoon culminant period. During the process of the "south" teleconnection’s formation, the Asian monsoon circulation has experienced a series of important changes: ISM onset, the northward movement of the south Asia high (SAH), the onset vortex occurrence, the eastward extension of the stronger tropical westerly belt, and the northeastward jump of the western Pacific subtropical high (WPSH), etc. Consequently, since ISM sets up over Kerala, the whole Asian continent is covered by the upper SAH after about two weeks, while in the mid- and lower troposphere, a strong wind belt forms from the Arabian Sea via the southern India, BOB and the South China Sea (SCS), then along the western flank of WPSH, to the Yangtze River Valley and southern Japan. With the northward moving of the subtropical jet streams, the upper westerly jet stream and the low level jet have been coupled ver- tically over east Asia, while the Yangtze River Valley happens to locate in the ascending motion

关键词： Indian summer monsoon (ISM) the Meiyu over the Yangtze River Valley teleconnection mode

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A SAR sidelobe suppression algorithm based on modified spatially variant apodization

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Science China(Technological sciences) 2010年第9期53卷 2542-2551页

作者： NI Chong1,2.WANG YanFei1,XU XiangHui1,ZHOU ChangYi1 & CUI PengFei1,2.1 Institute of Electronics,chinese academy of {2.,beijing 100190,China 2.graduate University of chinese academy of {2.,beijing 100039,China 1. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100039 China

The existing spatially variant apodizations (SVAs) either cannot depress the sidelobes effectively or reduce the energy of the *** improve this,a modified SVA (MSVA) is put forward in this paper,which expands the traditional filter from 3-taps to 5-taps and sets relevant parameters according to different sampling rates to get the excellent result that satisfies constrained optimization theory.A method for synthetic aperture radar (SAR) sidelobe control based on MSVA is presented,which applies MSVA to range compression and azimuth compression to control *** method which is available for any Nyquist sampling rate can both depress the sidelobes effectively and keep the energy of the mainlobe and the resolution of the *** method can reduce sidelobe levels more effectively than classical amplitude weighting while maintaining the image resolution,as demonstrated by the result of the experiment.

关键词： synthetic aperture radar sidelobe suppression resolution SVA

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Twistor bundle theory and its application

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Science China Mathematics 2004年第4期47卷 605-616页

作者： PENG Chia-Kuei & TANG ZizhouDepartment of Mathematics, graduate school of {2. academy of sciences, beijing 100039, China Department of Mathematical sciences, Tsinghua University, beijing 100084, China 1. Department of Mathematics Graduate School of Chinese Academy of Sciences 100039 Beijing China 2. Department of Mathematical sciences Tsinghua University 100084 Beijing China

Over an oriented even dimensional Riemannian manifold(M 2. ,ds2.), in terms of the Levi-Civita connection form Ω and the canonical form Θ on the bundle of positive orthonormal frames, we give a detailed description of the twistor bundle Гm = SO(2.)/U(m)? J +(@#@ M,ds2.) →M. The integrability on an almost complex structureJ compatible with the metric and the orientation, is shown to be equivalent to the fact that the corresponding cross section of the twistor bundle is holomorphic with respect toJ and the canonical almost complex structureJ 1 onJ +(M,ds2.), by using moving frame theory. Moreover, for various metrics and a fixed orientation onM, a canonical bundle isomorphism is established. As a consequence, we generalize a celebrated theorem of LeBrun.

关键词： almost complex structure, integrability, twistor bundle.

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Compositions of heavy minerals in Northeastern China sandlands and provenance analysis

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Science China Earth sciences 2007年第11期50卷 1715-1723页

作者： XIE Jing1,2.& DING ZhongLi1 1 Institute of Geology and Geophysics, chinese academy of {2., beijing 10002., China 2.graduate University of chinese academy of {2., beijing 100049, China 1. Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China 2. graduate University of chinese {2. of sciences Beijing 100049 China

Sand samples deposited since the Last Glacial Maximum (LGM) from the Hulun Buir, Horqin and Otin-dag sandlands were measured for their assemblages of heavy minerals and chemical compositions of detrital garnets and tourmalines. Heavy mineral assemblages of these three sandlands consist mainly of garnet, ilmenite, epidote and minor amphibole and magnetite. Garnets consist mainly of high Mg type-A ones (58% on average), and minor type-B ones. Toumalines are mainly composed of Mg-rich and minor Fe-rich ones. Compared with those of central-southern Mongolia and central Tarim, these three sandlands are derived from the Phanerozoic rocks of the Central Asian Orogenic Belt and the Archean and Paleoprotorozoic basement rocks of the North China Craton. Our results provide direct evidence that the present-day sands may be reworked from LGM ones. Differences of heavy mineral composi-tions occur between the samples of the three sandlands and Taklimakan Desert, indicating that the material of the western arid regions contributes little to the eastern sandlands.

关键词： heavy minerals,provenance,Northeastern China,garnet,tourmaline

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Isolation and Characterization of Photosystem Ⅱ of Porphyra yezoensis Ueda

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Acta Biochimica et Biophysica Sinica 2004年第11期36卷 780-785页

作者： Zheng-Quan GAO, Guang-Ce WANG, and Cheng-Kui TSENGKey Laboratory of Experimental Marine Biology, Institute of Oceanology, the chinese academy of {2., Qingdao 2.6071, China graduate school, the chinese academy of {2., beijing 100039, China Key Laboratory of Experimental Marine Biology Institute of Oceanology the Chinese Academy of SciencesQingdao 266071 China graduate school the Chinese Academy of SciencesBeijing 100039 China

The thylakoid membranes were isolated and purified from gametophyte of Porphyra yezoensis Ueda (P. yezoensis) by sucrose density gradient ultracentrifugation. After P. yezoensis gametophyte thylakoid membranes were so... 详细信息

关键词： red algae Porphyra yezoensis Ueda photosystem Ⅱ polypeptide composition extrinsic protein

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Calculations for the Pre-Calibration of LAMOST Active Optics

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chinese Journal of Astronomy and Astrophysics 2005年第3期5卷 302-314页

作者： Yong Zhang and Xiang-Qun Cui National Astronomical Observatories / Nanjing Institute of Astronomical Optics & Technology, chinese academy of {2., Nanjing 2.0042.graduate school of the chinese academy of {2., beijing 100039 graduate school of the {2. academy of sciences Beijing 100039

Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) is one of the major on-going national large scientific projects in China. Active optics is a key technology for the LAMOST with which the thin-mirror active optics and segmented-mirror active optics are tied in. A pre-calibration method considering all active forces and displacements specially for LAMOST has been developed in early 2.04. We give a detailed mathematical derivation and calculation including numerical simulation and computer program realization of the pre-calibration method of LAMOST open-loop control for the third-order aspherical aberration. We have also carried out calculations on the application of the pre-calibration method and the parameters of actuator design in LAMOST active optics in observation mode, including estimations of the actuator ranges, the interval of active optics correction and the ranges and trends of load changes on all the actuators during LAMOST tracking a given star.

关键词： active optics telescopes instrumentation

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