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Application of the three-dimensional telegraph equation to cosmic-ray transport

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Research in Astronomy and Astrophysics 2016年第10期16卷 107-115页

作者： Robert C. Tautz Ian Lerche Zentrum fur Astronomie und Astrophysik Technische Universitat Berlin HardenbergstraBe 36 D-10623 Berlin Germany institut fur geowissenschaften Naturwissenschaftliche Fakultat Ⅲ Martin-Luther-Universitat Halle D-06099 HalleGermany

An analytical solution to the three-dimensional telegraph equation is presented. This equation has recently received some attention but so far the treatment has been one-dimensional. By using the structural similarity to the Klein-Gordon equation, the telegraph equation can be solved in closed form. Illustrative examples are used to discuss the qualitative differences from the diffusion solution. A comparison with a numerical test-particle simulation reveals that some features of an intensity profile can be better explained using the telegraph approach.

关键词： plasmas -- turbulence -- magnetic field -- diffusion -- solar wind

Single zircon evaporation ages: Evidence for the Mesoproterozoic crust in the southeastern Nigerian basement complex

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Chinese Journal Of Geochemistry 2012年第1期31卷 48-54页

作者： Ekere E.Ukwang Barth N.Ekwueme Alfred Krner Department of Geology University of CalabarEtta AgborP.M.B.1115 CalabarNigeria institut fur geowissenschaften Universitat MainzGermany

The Ukwortung area of the Obudu Plateau exposes high-grade metamorphic rocks of upper amphibolite to granulite facies. Zircon grains from three locations of Southwest Obudu Plateau were dated by the Pb-Pb dating method. This single zircon radiometric dating method confirms the occurrence of Mesoproterozoic crust in the southeastern Nigeria basement complex. The pyroxene gneiss (granulite facies) sample from Biereberi near Ukpe yielded a mean age of 2061.4±0.4 Ma, suggesting the presence of Paleoproterozoic crust. The combined 207Pb/206Pb ratios from the garnet-biotite gneiss in the area gave a mean age of 1794.4±0.4 Ma. This further confirms the pres-ence of Paleoproterozoic crustal components within the Obudu Plateau. The Mesoproterozoic (1548.8±0.5 Ma) and Neoproterozoic (619.8±0.9 Ma) ages were obtained from two populations of zircon grains from the leucogranite in Okordem, Southwest Obudu. These "signatures" collaborate the occurrence of Mesoproterozoic ages in the Afar region and Cameroon basements along with the southeastern Nigerian basement complex, constituting the major portion of the West Central African mobile belt. The zircon age of 1794.4±0.4 Ma may probably be the maximum depositional age of the meta-sediment (garnet-biotite gneiss) and the age of 1548.8±0.5 Ma may be interpreted as the time of emplacement of the granitoid. The Neoproterozoic age (619.8±0.9 Ma) probably records the metamorphic event that was prevalent during the Pan-African period and thus affected the area.

关键词：单颗粒锆石平均年龄地壳成分中元古代尼日利亚地下室东南部证据

The lacustrine sedimentary records of coal-burning atmospheric pollution

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Science China Earth Sciences 2005年第10期48卷 1740-1746页

作者： E. Appel V. Hoffmann institut für geowissenschaften Universitt Tübingen 72076 Tübingen GermanyInstitut für Geowissenschaften Universitt Tübingen 72076 Tübingen Germany

Based on the studies on diatom, ostracods and magnetism on a core acquired from lacustrine sediments, as well as correlation analysis between concentration of acid diatom and the instantaneous lowest pH value, the processes of environment evolution in Lake Yangzonghai were reconstructed. The lacustrine environment was favorable in the 1950s, and began to be polluted by a coal-burning power plant since 1960. During 1965―1980, the instantaneous lowest pH value of lake water decreased to 5―6 when heavily polluted. There was a decrease trend in the pollution from 1983 to 1999, but coal-burning atmospheric pollution was still a main problem for environmental retrieving. As acid precipitated, acid-tolerant species overspread, and shellfish disappeared, as well as ferromagnetic particulates dissolved because of the consequent change of pH-Eh values in the interface of water and soil, which results in the change of environmental proxies versus depth. Thus, the environmental evolution of Lake Yangzonghai is reconstructed in this paper based on the inferences mentioned above.

关键词： atmospheric pollution, proxies, environmental reconstruction, lacustrine sediment, Lake Yangzonghai.

Application of microprobe-based flank method analysis of Fe^3＋ in garnet ofNorth Qilian eclogite and its geological implication

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Science Bulletin 2018年第5期63卷 300-305页

作者： Xiaoli Li Shuguang Song Lifei Zhang E. Heidi Hofer The Key Laboratory of Orogenic Belts and Crustal Evolution MOE School of Earth and Space Sciences Peking University Beijing 100871 China institut fur geowissenschaften Facheinheit Mineralogie Johann Wolfgang Goethe-Universitat D-60054 Germany

A newly developed microprobe-based methodology(the Flank Method)for Fe^(3+)/RFe quantification has been successfully applied to some natural garnets from the North Qilian eclogites by JEOL JXA-8100microprobe at Peking *** results demonstrated an obvious discrepancy in comparison with the outcomes by conventional stoichiometric *** methodology allows to measure theFe^(3+)/Rmeasurement of Fe^(3+)According to the compositional zonation displayed in the studied eclogitic garnets from North Qilian,a prograde metamorphic°C to 22 kbar,600°C was *** interestingly,the measured Fe^(3+)/RFe ratios in garnets decreasing from core to rim may probably imply that the oxygen fugacity(f O_2)declines with the depth of the subduction zone.

关键词： Microprobe Flank method Ferric iron GarnetNorth Qilian eclogite

U-Pb zircon ages for the Luzhenguan Complex in northern part of the eastern Dabie orogen

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Science China Earth Sciences 2005年第9期48卷 1357-1367页

作者： Wolfgang Siebe institut für geowissenschaften Universit?t Tübingen Tübingen 72074 Germany

The study presents U-Pb zircon ages for granitic gneiss and amphibolite from the Luzhenguan Complex (LZC) in northern part of the eastern Dabie Orogen and their geological significance. Two granitic gneisses and one amphibolite give protolith zircon U-Pb ages of 740 Ma and 725 Ma, respectively. The ages show that the LZC is composed mainly of Neoproterzoic acid and basic igneous rocks, suggesting that there is no Paleozoic active continental marginal rock association in the southern margin of the North China Block in northern part of the eastern Dabie Mountain. Based on the ages and combining the geological and geophysical analyses, the middle-low grade metamorphic rocks in the North Huiyang Belt (NHB) can be divided into three parts, which are the LZC composed mainly of the Neoproterzoic acid and basic igneous rocks, the Neoproterzoic Xianrechong Formation and Xiangyunzhai Formation and the Devonian Zhu- foan Formation and Pangjialing Formation of the Foziling Group, and the suture zone between the Yongtze Block and the North China Block is inferred to be thrust under the NHB.

关键词： Dabie orogen, Luzhenguan Complex, U-Pb zircon age, Neoproterzoic.

Temperature-depth control of petroleum occurrence in the sedimentary section of the South Caspian basin

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Petroleum Research 2020年第1期5卷 70-76页

作者： A.A.Feyzullayev Ian Lerche institute of Geology and Geophysics of Azerbaijan National Academy of Sciences H.Cavid av.119BakuAZ1143Azerbaijan institut fur geowissenschaften Naturwissenschaftliche FakultatⅢMartin-Luther-UniversitatGermany

This study analyses the temperature and depth control of well productivity(oil and gas),density of hydrocarbons(HC)and gas/liquid HC ratio(GLR)of petroleum fields in the South Caspian Basin(SCB).The database includes more than 700 field data from 54 onshore and offshore fields,which were processed to provide graphical and statistical analysis using standard computer *** was established that the peak of initial production and proven oil reserves falls in the temperature range 50-70℃.The oils of this interval are characterized by medium(about 890 kg/m^(3))and light(about 806 kg/m^(3))*** maximum condensate and gas production are in the temperature range 100-120℃,associated with the discovery and operation of large gas condensate fields in the deepwater part of the *** HC are represented in this temperature interval by“volatile”oils and condensates with an average density of 777-802 kg/m^(3).Low values of GLR are typical for temperatures below 70℃,associated both with poor gas conservation conditions and relatively high volumes of oil *** carbon isotope composition of methane indicates an exclusively catagenetic(thermal)origin at temperatures>50℃ and both catagenetic and mixed(microbiological-catagenetic)at temperatures<50℃.Based on the results,a forecast is provided for the discovery of new commercial HC accumulations.

关键词： Oil Condensate Gas Well productivity Temperature zonality SCB

Wilsonian Renormalization Group and the Lippmann-Schwinger Equation with a Multitude of Cutoff Parameters

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Communications in Theoretical Physics 2018年第3期69卷 303-307页

作者： E.Epelbaum J.Gegelia Ulf-G.Meiβner institut fur Theoretische Physik ii Ruhr-Universitat Bochum D-44780 Bochum Germany institute for Advanced Simulation Institut fur Kernphysik and Julich Center for Hadron Physics Forschungszentrum Jiilich D-52425 Julich Germany Tbilisi State University 0186 Tbilisi Georgia Helmholtz institut fur Strahlen und Kernphysik and Bethe Center for Theoretical Physics Universitat Bonn D-53115 Bonn Germany

The Wilsonian renormalization group approach to the Lippmann-Schwinger equation with a multitude of cutoff parameters is introduced.A system of integro-differential equations for the cutoff-dependent potential is *** an illustration,a perturbative solution of these equations with two cutoff parameters for a simple case of an S-wave low-energy potential in the form of a Taylor series in momenta is *** relevance of the obtained results for the effective field theory approach to nucleon-nucleon scattering is discussed.

关键词： nucleon-nucleon scattering effective field theory renormalization group

Constraints on sedimentary ages of the Chuanlinggou Formation in the Ming Tombs, Beijing, North China Craton: LA-ICP-MS and SHRIMP U–Pb dating of detrital zircons

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Acta Geochimica 2018年第2期37卷 257-280页

作者： Jing Ding Yuruo Shi Alfred Kroner J. Lawford Anderson Beijing SHRIMP Center Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China China University of Geosciences Beijing 100083 China institut fur geowissenschaften Universitat Mainz55099 Mainz Germany Department of Earth and Environment Boston University Boston MA 02215 USA

Detrital zircons in five sedimentary samples, MC1 to MC5, from the bottom of the Chuanlinggou Formation in the Ming Tombs District, Beijing, were dated with the LA-ICP-MS and SHRIMP U-Pb methods. Age spectra of the five samples show a major peak at 2500 Ma and a secondary peak at 2000 Ma, suggesting their provenances were mainly from the crystalline basement of the North China Craton and the Trans-North China Orogen. The youngest zircon has an age of 1673 d： 44 Ma, indicating that the Chuanlinggou Formation was deposited after this age. From sample MC4 to MC5, lithology changed from a clastic rock （fine-grained sandstone） to a carbonate rock （fine-grained dolomite）, suggesting that the depositional basin became progressively deeper. The age spectrum of sample MC5 shows a major peak at 2500 Ma and a secondary peak at 2000 Ma. Sample MC4, which is stratigraphically lower than sample MC5, only had one peak at 2500 Ma. We conclude that there was a transgressive event when sediments represented by MC5 was deposited, and seawater carried ca. 2000 Ma clastic materials to the basin where the Chuanlinggou Formation was deposited, leading to the addition of ca. 2000 Ma detritus. Our research indicates that the source area for the sediments became more extensive with time. We conclude that the Chuanlinggou Formation in the Ming Tombs District was deposited in a low-energy mud fiat sedimentary environment in the inter-supra tidal zone because it is mainly composed of silty mudstone and fine-grained sandstone with relatively simple sedimentary structures.

关键词： Detrital zircon LA-ICP-MS U-Pb ages SHRIMP Chuanlinggou Formation Ancient sedimentary environment North China Craton

A TAXONOMICAL AND ECOLOGICAL OVERVIEW OF RECENT AND HOLOCENE OSTRACODES OF THE NAM CO REGION, SOUTHERN TIBET

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第四纪研究 2009年第4期29卷 665-677页

作者： C. Wrozyna P. Frenzel Manping Xie Liping Zhu A. Schwalb institut far Umweltgeologie Technische Universit~it Braunschweig PockelsstraBe 3 38106 Braunschweig Germany institut fur geowissenschaften Friedrich-Schiller-Universitat Burgweg 11 07749 Jena Germany institute of Tibetan Plateau Research Chinese Academy of Sciences BeijingChina

We present a list of living and (sub) fossil Ostracoda (Crustacea) from Holocene sediments from Lake NamCo,Southern Tibet, including descriptions, distribution and ecological data of the important taxa from the Nam Cocatchment. Species associations from lake surface sediments, sediment cores and outcrop samples consist of eight speciesincluding Candona candida ( O.F. Müller, 1776 ) , Candona xizangensis ( Huang, 1982 ) , Eucypris afghanistanensis( Hartmann, 1964) , Fabaeformiscandona danielopoli ( Yin & Martens, 1997 ) , Ilyocypris cf. mongolica ( Martens, 1991 ) ,? Leucocythere dorsotuberosa ( Huang, 1982 ) , Leucocytherella sinensis ( Huang, 1982 ) and Limnocythere inopinata ( Baird,1843). The dominant species are ? L. dorsotuberosa and L. sinensis. They show morphological variations with different degreesof ornamentation. We regard the variable noding and rib formation as intraspecific variability possibly driven byenvironmental factors. In general,the number and degree of ribs increases with water depth in ? L. dorsotuberosa. Thus,theornamentation may present a means to reconstruct(paleo) water depths. Our list is intended to serve as a taxonomical andpaleoecological primer for future paleolimnological work.

关键词：化石甲壳类西藏沉积物