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The simulation of GCRs at near earth interplanetary locations for radioprotection

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Science China(Physics,Mechanics & Astronomy) 2010年第9期53卷 1739-1745页

作者： BAO Gang Purple Mountain Observatory,Chinese academy of sciences,nanjing 210008,China 1. Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China

The interplanetary radiation environment is detrimental to space missions,giving rise to cumulative damage to both astronauts and payloads and enhanced background levels in ***,there is a pressing need for a reliable simulation of these harmful effects for risk assessment and shielding optimization in manned space *** have modeled the interaction processes of the two most abundant galactic cosmic ray particle fluxes(protons and helium nuclei) using the Geant4.toolkit for a given space vehicle *** total energy deposited due to protons and helium nuclei is calculated in this work,and the energy deposited due to the secondary particles generated by this radiation is also estimated.

关键词： radioprotection simulation Geant4 cosmic rays

THREEDIMENSIONAL NUMERICAL SIMULATION OF WINDINDUCED CIRCULATION IN LAKE TAIHU

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Journal of Hydrodynamics 2004年第3期16卷 341-349页

作者： LUOLian-cong QINBo-qiang nanjingInstituteofGeographyandLimnology ChineseAcademyofSciencesNanjing210008China

A three-dimensional (3-D) numerical circulation model for shallow-lake ispresented and described in detail in this paper, which employs model-splitting technique in order tocalculate water level, mean-depth velocities and horizontal and vertical velocities at differentdepth simultaneously. The results show the current circulation pattern features four eddies with twoclockwise and two anticlockwise induced by prevailing wind. Opposite wind field will lead toopposite current pattern with phase shifted by 180° The surface convergence zone is located in theupwind area and the surface divergence part in the downwind region, This results in drastic verticalmovement in the two zones and the return currents at the bottom with phase shifted by 180° fromthe surface current vectors. Thus the water level decreases significantly at the leeward side andincreases quickly at the windward part. Verification and calibration for the model were made basedon the water-level and current data observed during the 9711 Storm in Lake Taihu. The predictedresults are in satisfactory agreement with the observed data, which raises the possibility that thismodel can be used to decide the bottom current stress for sediment resuspension and also tosimulate sediment transportation. It can provide a fundamental tool to study the nutrient releasefrom bottom sediment in Lake Taihu.

关键词： numerical simulation three dimensional hydrodynamics lake taihu

Near-Infrared Observations of the Massive Star Forming Region IRAS 23151+5912

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Chinese Journal of Astronomy and Astrophysics 2004年第3期4卷 284-298页

作者： Xue-Peng Chen Yong-Qiang Yao Purple Mountain Observatory Chinese academy of sciences, nanjing 210008 Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008

Near-infrared images and K-band spectroscopy of the massive star-formingregion IRAS 23151+5912 are presented. The JHK′ images reveal an embedded infrared clusterassociated with infrared nebula, and the H_2 (2.12 μm) narrowband image provides for the first timeevidence of outflow activity associated with the cluster. That the cluster is young can be shown bythe high percentage of infrared excess sources and the outflow activity. We suggest an age of thecluster of ～ 10~6 yr. Eight young stars are found in the bright nebular core around IRAS23151+5912. By the color-magnitude diagrams of the cluster, we found five high-mass YSOs and fourintermediate-mass YSOs in the cluster. Eight H_2 emission features are discovered in the region witha scattered and non-axisymmetric distribution, indicating the existence of multiple outflows drivenby the cluster. Diffuse H_2 emission detected to the north and to the west of the cluster mayresult from UV leakage of the cluster. Brγ, H_2, and CIV emission lines are found in the K-bandspectrum of the brightest source, NIRS 19, indicating the presence of envelope, stellar wind, andshock in the circumstellar environment. We have estimated an O7-O9 spectral type for the centralmassive YSO (20 ～ 30 solar mass), with an age of less than 1 x 10~6 yr.

关键词： infrared radiation stars: formation ISM: individual: IRAS 23151 + 5912 ISM: jets and outflows

Quantitative Relationship Between Land Use and Phosphorus Discharge in Subtropical Hilly Regions of China

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Pedosphere 2003年第1期13卷 67-74页

作者： YANG JINLING and ZHANG GANLINInstitute of Soil Science, the Chinese academy of sciences, nanjing 210008 (China) Institute of Soil Science the Chinese Academy of Sciences Nanjing 210008 (China)

The increase of phosphorus concentration is a crucial factor causing the eutrophication of water body,while land use has an important impact on agricultural non-point sources (NPS) phosphorus discharge. Sevensites controlling the water in four sub-watersheds and the main exit of the Meicun Watershed of XuanchengCounty, Anhui Province, were investigated by dynamic monitoring of stream water and nutrient discharge,integrating interpretation of aerial image and GIS analysis to find out how the land use affects phosphorusloss with stream water in typical agriculture-forest watershed in subtropical China. These monitored sitesare different in structure of land use. Phosphorus concentration of the stream water was analyzed everyweek and at the next day of rainfall. The velocity of flow was measured by kinemometer to calculatethe runoff flux and phosphorus discharge. The results showed that the runoff flux and the discharges ofdissolved phosphorus (DP), particle-associated phosphorus (PAP) and total phosphorus (TP) had significantexponential relationships with the area percentages of forest, pond and paddy field. There existed a significantlinear relationship between the TP and PAP concentrations in stream water and the area percentages of forest,pond and paddy field, and the discharge of PAP was also significantly linearly correlated with the dischargeof suspended soil particles. There was a logarithmic linear relationship between DP and PAP discharges. Thestudy indicated that the adjustment of land use patterns and construction of ecologically sound landscapewould be an important measure to reduce the runoff discharge of phosphorus. The results would be veryuseful in building the best management practices (BMPs) of agricultural watershed in subtropics.

关键词： land use phosphorus runoff watershed

Projection Effects on Physical Parameters Obtained from Solar Vector Magnetograms

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Chinese Journal of Astronomy and Astrophysics 2002年第2期2卷 174-182页

作者： Hui Li Purple Mountain Observatory, Chinese academy of sciences, nanjing 210008 National Astronomical Observatories, Chinese academy of sciences, Beijing 100012 Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 []National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

Projection effects in Huairou solar vector magnetograms are corrected by transferring or mapping the observed vector magnetogram in the image plane to the heliographic plane (planar correction) and to the heliospheric coordinate system (spherical correction). The magnetograms after the correction are considerably dif- ferent. The planar correction and the spherical correction lead to slightly different magnetic configurations, especially when the active region involved is far from the disk center. We also discuss the effects of the corrections on magnetic activity pa- rameters, such as magnetic shear, current helicity, etc. It is shown that the neutral line is obviously distorted after the mapping. The mapping generally decreases the average shear angle on the neutral line by several degrees when the active region is in the eastern hemisphere, and increases it when in the western hemisphere. In most of the cases studied, the correction reduces the current helicity imbalance, and sometimes even changes its sign. It is found that the current helicity imbalance may change its sign in its evolution when there are apparent fluxes emerging from the lower photosphere. The corrections increase the noise level of Bz greatly, and decrease the noise level of B~ slightly. The accuracy of the magnetic field measure- ment at Huairou is estimated to be better than 20 G and 150 G for the longitudinal and the transverse component, respectively.

关键词： Sun: magnetic fields ─Sun: activity ─Sun: photosphere

Lower Cretaceous angio-sperm leaf from Wuhe in Anhui,China

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Chinese Science Bulletin 2003年第6期48卷 611-614页

作者： LI Haomin nanjing Institute of Geology and Palaeontology, Chinese academy of sciences, nanjing {4., China nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences China

A new early angiosperm leaf species is reported from the Xinzhuang Formation in Wuhe County, Anhui Province. It is probably of Barremian or slightly later in geological age. The fossil leaf is small, no more than 0.6 cm both in length and in width. The leaf veins are well preserved and clearly visible under a low power microscope. Leaf ar-chitectural analysis shows that such a leaf should belong to the first leaf rank of Hickey, i.e. the most primitive one. There are no early angiosperm leaves published completely similar to ours. A new species name of Dicotylophyllum minutissimum sp. nov. is established for the present leaf fos-sils.

关键词：安徽下白垩统早期被子植物叶片结构叶片化石

The discovery of aeschnidiid nymphs (Aeschnidiidae, Odonata, Insecta)

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Chinese Science Bulletin 2000年第11期45卷 1031-1038页

作者： ZHANG Junfengnanjing Institute of Geology and Palaeontology, Chinese academy of sciences, nanjing {4., China nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China

Aeschnidiid nymphs are here first identified and described, and its phylogenetic relationship and bioecological characteristics are deduced. The nymphs known from China, Mongolia, Russia and Brazil and arranged in the family Aeschnidiidae are, in fact, unrelated to this group. All the known five Chinese species in four genera which were erected based on fossil nymphs and placed in the family Gomphidae may be transferred in Aeschnidiidae and merged into one alone, the Sinaeschnidia cancellosa. It is a geographically widespread species from the 'Jehol biota' of East Asia and appeared in the latest Late Jurassic age.

关键词： Jehol biota Aeschnidiidae dragonfly nymphs.

Nutrient Discharges from a Typical Watershed in the Hilly Area of Subtropical China

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Pedosphere 2003年第1期13卷 23-30页

作者： ZHANG GANLIN, YANG JINLING and ZHAO YUGUOInstitute of Soil Science, the Chinese academy of sciences, nanjing 210008 (China) Institute of Soil Science the Chinese Academy of Sciences Nanjing 210008 China

Agriculture is still the biggest contributor of non-point source (NPS) pollution to water bodies andrunoff discharges of nutrients and other chemicals are one of the most important pathways. This studywas conducted during 1998～1999 in a typical watershed with complex agriculture and forestry systems aswell as dotted farmer villages, in a transitional region between the mid- and northern subtropical zones ofChina. Continuous sampling of stream water was performed regularly at a weekly frequency, with additionalsampling after all major rainfall events. The discharges of N and P nutrients and suspended materials weremeasured and the total and area-averaged annual discharges of all components were calculated. The resultsshowed an uneven seasonal distribution of nutrient discharges with summer storms contributing most tothe total fluxes. This study demonstrated a high dependence of runoff volume on rainfall but the overallrunoff coefficients were dependent on land use type and watershed size. The area-averaged annual dischargesvaried greatly among the sub-watersheds with different sizes and land use structures. This is the first studyestimating the area-averaged annual discharges of N and P in the hilly areas of subtropical China, which were1.5 g m-2 a-1 and 0.1 g m-2 a-1, respectively, providing important reference values for the assessment ofregional agricultural non-point source pollution.

关键词： discharge nutrients runoff subtropical china watershed

Discovery of Cathaysiodendron Lee from the Early Carboniferous of Jingyuan,Gansu,western China

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Progress in Natural Science:Materials International 2004年第10期14卷 63-66页

作者： WANG Jun and WU Xiuyuan (nanjing Institute of Geology and Palaeontology,Chinese academy of sciences,nanjing{4.,China) Chinese Acad Sci Nanjing Inst Geol & Palaeontol Nanjing 210008 Peoples R China

As one of the representative members of the Late Palaeozoic Cathaysian flora,Cathaysiodendron has been previously recorded from the Early Permian Taiyuan and Shanxi Formations in north *** species of Cathaysiodendron presented here are from the lower member of Chouniugou Formation of Ciyao,Jingyuan,*** overlying marine beds yield fusulinids that are of Visean age in western Europe and conodonts of the Datang Stage in south China,so that the age of the bed containing Cathaysiodendron as Visean,Early Carboniferous,is well *** a record of Cathaysiodendron is significant in terms of Carboniferous phyto-geography and the evolution of the Cathaysian Lepidophytes.A new species,Cathaysiodendron jingyuanense Wang&Wu *** described and a second one mentioned.

关键词： Cathaysiodendron Early Carboniferous Visean Cathaysian flora