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The red damping wing of Gunn-Peterson trough in the high redshift GRBs

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Science China(Physics,Mechanics & Astronomy) 2009年第9期52卷 1428-1433页

作者： XU Zhou1,2 & WEI DaMing1,3 1 Purple Mountain Observatory, Chinese academy of sciences, nanjing 210008, China 2 Graduate University of Chinese academy of sciences, Beijing 100012, China 3 Joint Center for Particle Nuclear Physics and Cosmology of Purple Mountain Observatory-nanjing University, nanjing 210008, China Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China Graduate University of Chinese academy of sciences Beijing 100012 China Joint Center for Particle Nuclear Physics and Cosmology of Purple Mountain Observatory-nanjing University Nanjing 210008 China

We calculate the red damping wing of Gunn-Peterson trough taking the evolution of the neutral fraction into consideration and take a clear look at the ionized region around the ionizing sources. We get the result that the damping wing flux feature is mainly determined by the neutral hydrogen outside the ionized bubble and the cut off in the damping wing would be useful to get the size of the ionized bubble. We also fit the red damping wing of the recently discovered high redshift GRB080913 and find that the ionized bubble is too small to create apparent cut off in the spectrum of this burst.

关键词： cosmology theory intergalactic medium gamma ray burst

On the evolution and histology of some Cambrian protoconodonts, paraconodonts and primitive euconodonts

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Science China Earth sciences 2004年第7期47卷 577-584页

作者： DONG Xiping Department of Geology, Peking University, Beijing 100871, China Laboratory of Palaeobiology & Stratigraphy, nanjing Institute of Ge-ology and Palaeontology, Chinese academy of sciences, nanjing {4., China 1. Department of Geology Peking University 100871 Beijing China 2. Laboratory of Palaeobiology & Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences 210008 Nanjing China

Previous reports on the morphological evolution of protoconodonts and paraconodonts are reviewed. The evolutionary trends exhibited by species of the protoconodont genus Gapparodus and the paraconodont genus Westergaadodina are discussed. Based on the present study on histology, genus Paibiconus is protoconodont, while genus Yongshunella is paraconodont (fig. 1 (a)). However, the nature of Huayuanodontus has not been fully understood so far. Recently, the transitional form New Gen. Sensu Miller, 1980 of late Late Cambrian has been found in Hunan Province, South China. It is considered as the Sister-Group of Proconodontus. Moreover, another kind of transitional form of middle Late Cambrian and late Late Cambrian between Prooneotodus notundatus and Pnoconodontus, which looks like Prooneotodus notundatus in gross morphology, but has anterior and posterior costae, has also been found in Hunan, South China. This kind of transitional form is believed to be probably the real intermediate link between Prooneotodus rotundatus and Pnoconodontus, and Prooneotodus rotundatus is most probably the ancestor of Proconodontus. The two transitional forms noted above are all euconodonts by the study of their histology. Unlike the euconodonts of Post-Cambrian, the evolutionary relationships among the species of protoconodonts, paraconodonts and the primitive euconodonts could not be made clear without the histological study on them.

关键词： protoconodonts, paraconodonts, evolution, histology, Cambrian.

Test mass charging simulation of ASTROD I due to solar energetic particles at 0.5 AU

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Science China(Physics,Mechanics & Astronomy) 2010年第6期53卷 1139-1143页

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

Maintaining the geodesic motion of the test mass is vital to ASTROD I space mission. However,the electrostatic charging of the test mass due to cosmic rays and solar energetic particles will result in Coulomb and Lorentz forces and consequently influence the test mass motions. To estimate the size of these effects,a credible simulation of test mass charging processes is critically required. Using the GEANT4.software toolkit,we have modeled the charging processes and predict how the ASTROD I test mass will charge positively at a rate of 217370 e + /s,due to solar energetic particles(SEPs) at～0.5 AU caused by the largest SEPs event on 29,September,1989. In addition to Monte Carlo uncertainty,an error of ±30% in the net charging rates was added to account for uncertainties in the spectra,physics and geometry models.

关键词： charging simulation ASTROD I GEANT4 solar energetic particles

Hispanic Corridor formed as early as Hettangian: On the basis of bivalve fossils

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Chinese Science Bulletin 2002年第5期47卷 414-417页

作者： SHAJingengnanjing Institute of Geology and Palaeontology, Chinese academy of sciences, nanjing {4., China (e-mail: jgsha @***) nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China

After tracking the historical distribution of the pectinids being very capable of dispersion, it is easy to be found that the bivalves Chlamys (Chlamys) valoniensis (Defrance), Camptonectes (Camptonectes) auritus (von Schlo-theim) and Chlamys (Chlamys) textoria (von Schlotheim) first occurred in the Late Rhaetian, the end of the Triassic, or the earliest Hettangian, the earliest Jurassic of western Europe, and subsequently they spread into the southeastern coast of Palaeo-pacific through the Hispanic Corridor during the Hettangian or a little later. It has demonstrated that the Hispanic epicontinental seaway became established along the rifting area between North America and South America and Africa of the Pangaean supercontinent as early as Hettangian or even earlier, connecting western Tethys and eastern Palaeo-pacific and providing a corridor for migration and exchange of creatures between Tethys and Palaeo-pacific.

关键词： Hispanic Corridor form Hettangian.

Kalligrammatid Lacewings from the Upper Jurassic Daohugou Formation in Inner Mongolia, China

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Acta Geologica Sinica(English Edition) 2003年第2期77卷 141-147页

作者： ZHANG Junfengnanjing Institute of Geology and Palaeontology, Chinese academy of sciences, nanjing, Jiangsu {4., E-mail: jfzhang@*** Chinese Acad Sci Nanjing Inst Geol & Palaeontol Nanjing 210008 Jiangsu Peoples R China

A new species, referable to a new genus, is erected, and named the Sinokalligramma jurassicum gen. et sp. nov. It is the second finding of kalligrammatids in the Daohugou Formation. The origin and migration of the family Kalligrammatidae are discussed. The geological age and stratigraphic correlation of the Daohugou and Karabastau Formations are briefly reviewed and reassessed.

关键词： kalligrammatid lacewings new taxa age origin and migration Jurassic Inner Mongolia China

A Simulation Study on Effect of Surface Film-Forming Material on Water Evaporation

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Pedosphere 2001年第1期11卷 67-72页

作者： ZHUANG SHUNYAO, YIN BIN and ZHU ZHAOLIANG (Institute of Soil Science, the Chinese academy of sciences, nanjing 210008 (China)) 中科院南京土壤所江苏南京 210008

A greenhouse experiment was conducted to investigate the effect of surface film-forming material (SFFM), a mixture of 16-18-octadecanols by emulsification, on water evaporation. Air-dried soil with distilled water was incubated firstly for 7 days to reestablish soil biological activity and then for another 7 days after treated with SFFM at rates of 0, 1, 2, 4. 6 and 8 g m-2, respectively. Everyday during the 7-day incubation after addition of SFFM, water losses due to evaporation were ~measured by an electronic balance. The rate of water evaporation with the addition of SFFM was reduced significantly compared with the control treatment and the effectiveness of SFFM on water evaporation reduced with time. According to the equation expressions of the effect of SFFM on water evaporation, the half-life of electiveness of SFFM on water evaporation was introduced and calculated to analyze quantitative relationship between the effectiveness of SFFM on water evaporation and the addition rate of SFFM. The calculated half-life increased with the addition rate of SFFM and the confidence of the calculated values of the half-life was high, suggesting that the half-life of effectiveness of SFFM on water evaporation could be described quantitatively and may be helpful for ameliorating application method of SFFM and screening surface-film forming materials in order to improve nitrogen fertilizer use efficiency in flooded rice fields.

关键词： half-life of effectiveness surface film-forming material water evaporation

FOSSIL OPHIUROIDS FROM TONGZIYAN FORMATION(Middle PERMIAN) IN LONGYAN, FUJIAN

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古生物学报 2002年第3期 399-402页

作者： LIAO Zhuo Ting and WANG Xiao Juan (nanjing Institute of Geology and Palaeontology, the Chinese academy of sciences, nanjing {4.)

ＳｕｍｍａｒｙＴｈｅｆｏｓｓｉｌｏｐｈｉｕｒｏｉｄｓｄｅｓｃｒｉｂｅｄｉｎｔｈｉｓｐａｐｅｒｗａｓｃｏｌｌｅｃｔｅｄｆｒｏｍｔｈｅＴｏｎｇｚｉｙａｎＦｏｒｍａｔｉｏｎｎｅａｒｔｈｅＫｅｎｇｂｉｎｇＣｏａｌＭｉｎｅｉ... 详细信息

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关键词： echinoderms ophiuroids Middle Permian(Guadalupian) Longyan of Fujian Summary The fossil ophiuroids described in this paper was collected from the Tongziyan Formation near the Kengbing Coal Mine in Longyan. This formation is a suite of pa

Early-Mid Ordovician brachiopod diversification in South China

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Science China Earth sciences 2005年第5期48卷 662-675页

作者： ZHAN Renbin, RONG Jiayu, CHENG Jinhui & CHEN Pengfei nanjing Institute of Geology and Palaeontology, Chinese academy of sciences State Key Laboratory of Palaeobiology and Stratigraphy, nanjing {4., China 1. nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences State Key Laboratory of Palaeobiology and Stratigraphy 210008 Nanjing China

Affected by paleogeographic position, paleoclimatic condition and depositional environments, the increase of the Early-Mid Ordovician brachiopod diversity of South China commenced at the beginning of the Ordovician (early Tremadoc), accelerated from the Tetra- graptus approximatus Biozone (base of Arenig), and reached its first acme in the Didymograptus eobifidus Biozone (mid early Arenig) when the number of brachiopod genera was over 7 times as great as that at the start of the Ordovician. This was the first radiation in the history of brachiopod macroevolution in South China, which occurred nearly 5 graptolitic biozones earlier than the global trend of the great Ordovician biodiversification (in the lower part of the Undulograptus austrodentatus Biozone). It is also characterized by (1) the origination or first occurrences of some major groups, such as the punctate dalmanelloids and the pseudopunctate stro- phomenoids including Plectambonitoidea (cardinal process simple or absent) and Stro- phomenoidea (cardinal process bilobed) in South China; (2) niche expansion, particularly in the first occupation of deeper water benthic regimes by the Euorthisina-Nocturnellia Association developed at Houping, Chengkou, northern Chongqing; and (3) the differentiation of brachiopod faunas under different environmental conditions. The gradual and increasing separation from Gondwana may have been one of the factors responsible for the radiation in South China.

关键词： biodiversity, evolutionary radiation, brachiopods, Early-Mid Ordovician, South China.

Discrepancy between infrared and optical emission in some Be stars

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Chinese Science Bulletin 2002年第18期47卷 1511-1513页

作者： LIU Qingzhong & WEI JianyanPurple Mountain Observatory, Chinese academy of sciences, nanjing210008, China National Astronomical Observatories, Chinese academy of sciences, Beijing 100012, China Purple Mountain Observatory Chinese Academy of Sciences Nanjing China National Astronomical Observatories Chinese Academy of Sciences Beijing China

An expanding ring model is put forward to investigate the original regions of Ha line emission and infrared excess emission in Be stars, by taking optical depth into account. We find that the two regions depend strongly on the physical properties of the envelope of Be stars such as the initial density and density structure. This model can be used to qualitatively interpret the disagreement between the near infrared excess and the equivalent width (EW) of Ha emission line, as observed in some Be stars.

关键词： Be star emission line near infrared excess.