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A modified explanation of cold nuclear matter effects on J/ψ production in p+A collisions

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Chinese Physics C 2015年第8期39卷 56-61页

作者：刘植凤 institute of geophysics Shijiazhuang Economic University

A modified explanation of the cold nuclear matter （CNM） effects on J/ψ production in p＋A collisions is presented in this paper. The advantage of the modified explanation is that all the CNM effects implemented in this model have clear physical origins and are mostly centered on the idea of multiple parton scattering. With the CNM effects presented in this paper, we calculated the nuclear modification factor RpA in J/ψ production under different collision energies. The results are compared with the corresponding experiment data and the factors calculated with classic nuclear effects. The factors calculated with CNM effects presented in this paper can accurately reproduce almost all existing J/ψ measurements in p-A collisions, which is much better than results obtained with the factors calculated with classic nuclear effects. The new model is therefore a more suitable approach to explain CNM effects in the hardproduction of quarkonium.

关键词： quantum chromodynamics cold nuclear matter effects quark energy loss effect dynamical shadowingeffect gluon saturation

Review on study of seismotectonics in China

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Acta Seismologica Sinica(English Edition) 2003年第5期16卷 534-543页

作者：王椿镛刘琼林 institute of geophysics China Seismological Bureau

This paper reviews briefly the progresses made during the last four years (1999~2002) in study of seismotectonics in China, especially appraises the achievements in the fields of the crustal and upper mantles structure, the active faults and tectonic setting of large earthquakes, the crustal deformation, and the numerical simulation. Most earthquakes occurred in China belong to continental earthquakes. Therefore, Chinese seismologists pay more attention to the continental earthquakes. Based on improvements of the observation systems in China during the ninth Five-Year Plan, the studies on seismotectonics have achieved great progresses.

关键词： seismotectonics plate tectonics continental earthquake

First PPMXL photometric analysis of open cluster Ruprecht 15

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Research in Astronomy and Astrophysics 2012年第2期12卷 158-166页

作者： Ashraf Latif Tadross National Research institute of Astronomy & geophysics

We present the first in a series studying the astrophysical parameters of open clusters using the PPMXL＊ database whose data are applied to study Ruprecht 15. The astrophysical parameters of Ruprecht 15 have been est... 详细信息

关键词： open clusters and associations (individual: Ruprecht 15) -- astrometry-- stars -- astronomical databases: catalogs

S-wave velocity structure inferred from receiver function inversion in Tengchong volcanic area

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Acta Seismologica Sinica(English Edition) 2004年第1期17卷 12-19页

作者： HE Chuan-song(贺传松) WANG Chun-yong(王椿镛) WU Jian-ping(吴建平) institute of geophysics China Seismological Bureau Beijing 100081 China Institute of Geophysics China Seismological Bureau Beijing 100081 China Institute of Geophysics China Seismological Bureau Beijing 100081 China

Tengchong volcanic area is located near the impinging and underthrust margin of India and Eurasia plates. The volcanic activity is closely related to the tectonic environment. The deep structure characteristics are inferred from the receiver function inversion with the teleseismic records in the paper. The results show that the low velocity zone is influenced by the NE-trending Dayingjiang fault. The S-wave low velocity structure occurs obviously in the southern part of the fault, but unobviously in its northern part. There are low velocity zones in the shallow po-sition, which coincides with the seismicity. It also demonstrates that the low velocity zone is directly related to the thermal activity in the volcanic area. Therefore, we consider that the volcano may be alive again.

关键词： Tengchong volcanic area receiver functions S wave velocity structure thermal activity

Ambient noise surface wave tomography of the Makran subduction zone,south-east Iran:Implications for crustal and uppermost mantle structures

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Earthquake Science 2015年第4期28卷 235-251页

作者： Mahsa Abdetedal Zaher Hossein Shomali Mohammad Reza Gheitanchi institute of geophysics

Seismic ambient noise of surface wave tomography was applied to estimate Rayleigh wave empirical Green＇s functions （EGFs） and then to study crust and uppermost mantle structure beneath the Makran region in south-east 1mn. 12 months of continuous data from January 2009 through January 2010, recorded at broadband seismic stations, were analyzed. Group velocities of the fundamental mode Rayleigh wave dispersion curves were obtained from the empirical Green＇s functions. Multiple- filter analysis was used to plot group velocity variations at periods from 10 to 50 s. Using group velocity dispersion curves, 1-D Vs velocity models were calculated between several station pairs. The final results demonstrate signifi- cant agreement to known geological and tectonic features. Our tomography maps display low-velocity anomaly with SW-NE trend, comparable with volcanic arc settings of the Makran region which may be attributable to the geometry of Arabian Plate subducting beneath the overriding the Lut block. The northward subducting Arabian Plate is deter- mined by high-velocity anomaly along the Straits of Hor- muz. At short periods （〈20 s）, there is a sharp transition boundary between low- and high-velocity transition zone with the NW trending at the western edge of Makran which is attributable to the Minab fault system.

关键词： Ambient seismic noise Cross-correlationEmpirical Green's functions (EGFs) Surface wavetomography

Source mechanism of small-moderate earthquakes and tectonic stress field in Yunnan Province

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Acta Seismologica Sinica(English Edition) 2004年第5期17卷 509-517页

作者： WU Jian-ping(吴建平) MING Yue-hong(明跃红) WANG Chun-yong(王椿镛) institute of geophysics China Earthquake AdministrationBeijing100081China Institute of GeophysicsChina Earthquake AdministrationBeijing100081China Institute of GeophysicsChina Earthquake AdministrationBeijing100081China

In the paper, source mechanisms of 33 small-moderate earthquakes occurred in Yunnan are determined by modeling of regional waveforms from Yunnan digital seismic network. The result shows that most earthquakes occurred within or near the Chuandian rhombic block have strike-slip mechanism. The orientations of maximum compressive stresses obtained from source mechanism are changed from NNW-SSN to NS in the areas from north to south of the block, and tensile stresses are mainly in ENE-WSW or NE-SE. In the eastern Tibetan Plateau, the orientations of maximum compressive stress radiate toward outside from the plateau, and the tensile stress orientations mostly parallel to arc structures. Near 28N the orientations of both maximum compressive stress and tensile stress changed greatly, and the boundary seems to correspond to the southwestern extended line of Longmenshan fault. Outside of the Chuandian rhombic block, the orientations of P and T axes are some different from those within the block. The comparison shows that the source mechanism of small-moderate events presented in the paper is consistence with that of moderate-strong earthquakes determined by Harvard University, which means the source mechanism of small-moderate events can be used to study the tectonic stress field in this region.

关键词： source mechanism small-moderate earthquakes stress field Yunnan

Crust and upper mantle structure of the Ailao Shan-Red River fault zone and adjacent regions

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Science China Earth Sciences 2005年第2期48卷 156-164页

作者： XU Yi LIU Jianhua LIU Futian SONG Haibin HAO Tianyao JIANG Weiwei institute of Geology and geophysics Chinese Academy of SciencesBeijing100029China Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China

Using arrival data of the body waves recorded by seismic stations, we reconstructed the velocity structure of the crust and upper mantle beneath the southeastern edge of the Tibetan Plateau and the northwestern continental margin of the South China Sea through a travel time tomography technique. The result revealed the apparent tectonic variation along the Ailao Shan-Red River fault zone and its adjacent regions. High velocities are observed in the upper and middle crust beneath the Ailao Shan-Red River fault zone and they reflect the character of the fast uplifting and cooling of the metamorphic belt after the ductile shearing of the fault zone, while low velocities in the lower crust and near the Moho imply a relatively active crust-mantle boundary beneath the fault zone. On the west of the fault zone, the large-scale low velocities in the uppermost mantle beneath western Yunnan prove the influence of the mantle heat flow on volcano, hot spring and magma activities, however, the upper mantle on the east of the fault zone shows a relatively stable structure similar to the Yangtze block. The low velocities of the deep mantle beneath the southeastern extending segment of the fault zone are probably related to the mantle convection produced by the pull-apart of the South China Sea.

关键词： Ailao Shan-Red River fault zone, seismic tomography, crust and upper mantle, velocity structure.

Geochemistry of ore-forming fluids and geological significance of the Kuoerzhenkuola gold field in Xinjiang, China

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Science China Earth Sciences 2005年第11期48卷 1921-1931页

作者： SHEN Ping SHEN Yuanchao LIU Tiebing LI Guangming ZENG Qingdong institute of Geology and geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

The Kuoerzhenkuola gold field (including the Kuoerzhenkuola and the Buerkesidai gold deposits) is the most important one in the Sawuer gold belt, northern Xinjiang, China. Iso-topic studies including D, O, He, C, S, Pb and Sr reveal that the ore-forming fluids of the Kuo-erzhenkuola and the Buerkesidai deposits shared the same source: the water of ore fluids was magmatic water and minor meteoric water; the mineralizers and ore materials derived mainly from mantle beneath the island arc, and partially from crust. The ore-forming fluids of two depos-its are a mixture of mantle-derived fluids incorporated by crust-derived fluid, and meteoric water. Based on these results, combined with the consideration of the tectonic setting and geological features, we suggest that the two gold deposits in the Kuoerzhenkuola gold field, Sawur gold belt share the same genesis, and are volcanogenic hydrothermal gold deposits occurring in the same caldera.

关键词： ore-forming fluids, inclusions, isotope, volcanogenic late-stage hydrothermal gold deposits, Kuoerzhen-kuola gold field

Study on the characteristics of earthquake's impact on cities

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Acta Seismologica Sinica(English Edition) 2004年第2期17卷 222-229页

作者： PAN Hua(潘华) ZHAO Feng-xin(赵凤新) GAO Meng-tan(高孟潭) institute of geophysics China Earthquake Administration Beijing 100081 China Institute of Geophysics China Earthquake Administration Beijing 100081 China Institute of Geophysics China Earthquake Administration Beijing 100081 China

Firstly, the impact of historical earthquakes on 34 China province-level capital cities is evaluated by using historical earthquake catalog. The distribution of affected intensity shows, about 53% of cities have even not been affected by earthquake intensity VI, and 44% of cities have been hit by earthquake intensity VII to IX. For most of the cities, occurrence frequency of affected intensity VI is usually higher than that of affected intensity larger than VI, and the value of affected intensity with maximal occurrence frequency may be very different among cities. So both the maximal affected intensity and the affected intensity with maximal occurrence frequency should be taken into account when the prevention seismic intensity needs to be determined. Secondly, considering the incompleteness of records of historical earthquakes, a method of earthquake catalog computer simulation is introduced to study the features of affected intensity of big cities. 69 county-level cities of Fujian Province are selected to be statistical objects. The statistical result shows, for different risk levels the seismic intensity changes greatly among cities, the seismic intensity of 2% probability of exceedance in 50 years can be regarded as the characteristic affected intensity of city, and can be the basis of determining the city special earthquake prevention level and a proper indicator of future earthquakes impact on cities.

关键词： city group affected intensity characteristics earthquake probability of exceedance