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Physics of Interplanetary Dust

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紫金山天文台台刊 1996年第3期15卷 32-51页

作者： Eberhard Grun Max-Pi anck-institut fur Kernphysik 69117 Heidel berg.Germany

Zodiacal light is a promient light phenomenon to the human eye in the morning andevening sky in non-polluted areas. Already in 1683 Cassini presented the correct explanation ofthis phenomenon: it is sun light scattered by dust particles orbiting the sun. The reistion toother "dusty" interplanetary phenomena,like comets was soon suspected. Comets shed

关键词：山砂加压山岭血肠沙州比面加力山口日场衡山

Mechanical Properties of Single-Walled （5,5） Carbon Nanotubes with Vacancy Defects

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Chinese Physics Letters 2007年第7期24卷 2036-2039页

作者：袁士俊孔勇李发伸 Key Lab on Magnetism and Magnetic Materials of the Ministry of Education Lanzhou University Lanzhou 730000 Max-Planck-institut fur Metallforschung Heisenbergstrasse 3 70569 Stuttgart Germany

First-principles simulation is used to investigate the structural and mechanical properties of vacancy defective single-walled （5,5） carbon nanotubes. The relations of the defect concentration, distribution and characteristic of defects to Young＇s modulus of nanotubes are quantitatively studied. It is found that each dangling-bond structure （per supercell） decreases Young＇s modulus of nanotube by 6.1% for symmetrical distribution cases. However the concentrative vacancy structure with saturated atoms has less influence on carbon nanotubes. It is suggested that the mechanical properties of carbon nanotubes depend strongly upon the structure and relative position of vacancies in a certain defect concentration.

关键词： Mechanical Properties Single-Walled

Search for H I emission from superdisk candidates associated with radio galaxies

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Research in Astronomy and Astrophysics 2019年第6期19卷 71-78页

作者： Abhijeet Anand Nirupam Roy Gopal-Krishna Max-Planck-institut fur Astrophysik Karl-Schwarzschild-Str. 1 D-85741 Garching Germany Department of Physics Indian Institute of Science Bangalore - 560012 India Aryabhatta Research institute of Observational Sciences (ARIES) Manora Peak Nainital - 263129 India Max-Planck-institut fur Radioastronomie Auf dem Hugel 69 53121 Bonn Germany

Giant gaseous layers(termed “superdisks”) have been hypothesized in the past to account for the strip-like radio emission gap(or straight-edged central brightness depression) observed between twin radio lobes, in over a dozen relatively nearby powerful Fanaroff-Riley Class II radio galaxies. They could also provide a plausible alternative explanation for a range of observations. Although a number of explanations have been proposed for the origin of the superdisks, little is known about their material content. Some X-ray observations of superdisk candidates indicate the presence of hot gas, but a cool dusty medium also seems to be common. If they are entirely or partly composed of neutral gas, then it may be directly detectable and we report here a first attempt to detect/image any neutral hydrogen gas present in the superdisks that are inferred to be present in four nearby radio galaxies. We have not found a positive H I signal in any of the four sources, resulting in tight upper limits on the H I number density in the postulated superdisks,estimated directly from the central rms noise values of the final radio continuum subtracted image. The estimated ranges of the upper limit on neutral hydrogen number density and column density are 10^-4-10^-3 atoms per cm3 and 10^19-10^20 atoms per cm^2, respectively. No positive H I signal is detected even after combining all the four available H I images(with inverse variance weighting). This clearly rules out an H I dominated superdisk as a viable model to explain these structures, however, the possibility of a superdisk being composed of warm/hot gas still remains open.

关键词： galaxies:active galaxies:general galaxies:structure radio lines:galaxies

Functional analysis and drug response to zinc and D-penicillamine in stable ATP7B mutant hepatic cell lines

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World Journal of Gastroenterology 2016年第16期22卷 4109-4119页

作者： Gursimran Chandhok Judit Horvath Annu Aggarwal Mohit Bhatt Andree Zibert Hartmut HJ Schmidt Klinik fur Transplantationsmedizin Universitatsklinikum Munster D-48149 Munster Germany institut fur Humangenetik Westfalische Wilhelms-Universitat D-48149 Munster Germany Kokilaben Dhirubhai Ambani Hospital and Medical Research institute Mumbai 400103 India

AIM: To study the effect of anti-copper treatment for survival of hepatic cells expressing different ATP7 B mutations in cell culture. METHODS: The most common Wilson disease(WD) mutations p.H1069 Q, p.R778 L and p.C271*, found in the ATP7 B gene encoding a liver copper transporter, were studied. The mutations represent major genotypes of the United States and Europe, China, and India, respectively. A human hepatoma cell line previously established to carry a knockout of ATP7 B was used to stably express WD mutants. m RNA and protein expression of mutant ATP7 B, survival of cells, apoptosis, and protein trafficking were ***: Low temperature increased ATP7 B protein expression in several mutants. Intracellular ATP7 B localization was significantly impaired in the mutants. Mutants were classified as high, moderate, and no survival based on their viability on exposure to toxic copper. Survival of mutant p.H1069 Q and to a lesser extent p.C271* improved by D-penicillamine(DPA) treatment, while mutant p.R778 L showed a pronounced response to zinc(Zn) treatment. Overall, DPA treatment resulted in higher cell survival as compared to Zn treatment; however, only combined Zn + DPA treatment fully restored cell viability. CONCLUSION: The data indicate that the basic impact of a genotype might be characterized by analysis of mutant hepatic cell lines.

关键词： ATP7B D-penicillamine Zinc Mutations Wilson disease Therapy

Dynamic Analysis of Overhead Transmission Lines under Turbulent Wind Loading

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Open Journal of Civil Engineering 2015年第4期5卷 359-371页

作者： Alok Dua Mathias Clobes Thomas Hobbel Vasant Matsagar Department of Civil Engineering Indian Institute of Technology(IIT)DelhiIndia institut fur Stahlbau Technische Universitat Carolo‐WilhelminaBraunschweigGermany

Transmission tower-line systems are designed using static loads specified in various codes. This paper compares the dynamic response of a test transmission line with the response due to static loads given by Eurocode. Finite element design software SAP2000 was used to model the towers and lines. Non-linear dynamic analysis including the large displacement effects was carried out. Macroscopic aspects of wind coherence along element length and integration time step were investigated. An approach is presented to compare the probabilistic dynamic response due to 7 different stochastically simulated wind fields with the response according to EN-50341. The developed model will be used to study the response recorded on a test line due to the actual wind speed time history recorded. It was found that static load from EN overestimated the strength of conductor cables. The response of coupled system considering towers and cables was found to be different from response of only cables with fixed supports.

关键词： Dynamic Analysis Finite Element Method SAP2000 Transmission Towers Transmission Lines

The joint impact of bankruptcy costs, fire sales and cross-holdings on systemic risk in financial networks

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Probability, Uncertainty and Quantitative Risk 2017年第1期2卷 192-229页

作者： Stefan Weber Kerstin Weske institut fur Mathematische Stochastik Leibniz Universit¨at HannoverWelfengarten 130167 HannoverGermany

The paper presents a comprehensive model of a banking system that integrates network effects,bankruptcy costs,fire sales,and *** the integrated financial market we prove the existence of a price-payment equilibrium and design an algorithm for the computation of the greatest and the least *** number of defaults corresponding to the greatest price-payment equilibrium is analyzed in several comparative case *** illustrate the individual and joint impact of interbank liabilities,bankruptcy costs,fire sales and cross-holdings on systemic *** study policy implications and regulatory instruments,including central bank guarantees and quantitative easing,the significance of last wills of financial institutions,and capital requirements.

关键词： Systemic risk Financial contagion Financial network Cross-holdings Fire sales Bankruptcy costs

Magnetic reconnection events in the interplanetary space

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Science China(Technological Sciences) 1997年第5期40卷 463-471页

作者：魏奉思 R.Schwenn 胡强 Max-Planck-institut fur Aeronomie D-37189 Katlenburg-Lindau Germany. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China. Max-Planck-institut fur Aeronomic D-37189Katlenburg-LindauGermany. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China.

Magnetic field and plasma measurements in the period of 1975-1981 with 0. 18-h averages from Helios spacecrafts are analyzed. It is discovered that magnetic reconnection phenomena exist in the interplanetary space. By means of the reconstruction of magnetic field configuration in the azimuth angle plane, it is found that the magnetic reconnection event with time scale of the order of day is a significant form of magnetic reconnection phenomena in the interplanetary space, which consists of a mediate body (or a plasma bulk) and two magnetic separator lines. It could originate from coronal mass ejection event or magnetic cloud in the interplanetary space. Numerical simulation has reproduced the basic characteristics of the magnetic reconnection events.

关键词： interplanetary space magnetic reconnection hemispheric physics.

Bistability in Coupled Oscillators Exhibiting Synchronized Dynamics

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Communications in Theoretical Physics 2010年第5期53卷 815-824页

作者： O.I.Olusola U.E.Vincent A.N.Njah J.A.Olowofela Department of Physics University of Agriculture Department of Physics Lancaster University institut fur Theoretische Physik Technische Universitt Clausthal Department of Physics Olabisi Onabanjo University

We report some new results associated with the synchronization behavior of two coupled double-well Duffing oscillators （DDOs）. Some sufficient algebraic criteria for global chaos synchronization of the drive and response DDOs via linear state error feedback control are obtained by means of Lyapunov stability theory. The synchronization is achieved through a bistable state in which a periodic attractor co-exists with a chaotic attractor. Using the linear perturbation analysis, the prevalence of attractors in parameter space and the associated bifurcations are examined. Subcritical and supercritical Hopf bifurcations and abundance of Arnold tongues -- a signature of mode locking phenomenon are found.

关键词： chaos synchronization Duffing oscillator bistability Lyapunov stability theory

Refractive Focusing of Interstellar Clouds and Intraday Polarization Angle Swings

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Chinese Journal of Astronomy and Astrophysics 2007年第2期7卷 215-223页

作者： Shan-Jie Qian T. E Krichbaum Long Gao Xi-Zhen Zhang A. Witzel J. A. Zensus National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Max-Planck-institut fur Radioastronomie Auf dem Huge169 53121 Bonn Germany

Intraday variations of compact extragalactic radio sources in flux density and polarization are generally interpreted in terms of refractive scintillation from the continuous interstellar medium of our Galaxy. However, continuous polarization angle swings of - 180° （for example, the one observed in the QSO 0917＋624） could not be interpreted in this way. Qian et al. have shown that the polarization angle swing observed in the QSO 1150＋812 can be explained in terms of focusing-defocusing effect by an interstellar cloud, which occults two closely-placed polarized components. Here we further show that the polarization angle swing event observed in the QSO 0917＋624 can also be explained in this way. We also found evidence for the cloud eclipsing a non-polarized （core） component during a short period out- side the swing. A particular （and specific） plasma-lens model is proposed to model-fit the polarization swing event of 0917＋624. Some physical parameters related to the plasma-lens and the source components are estimated. The brightness temperatures of the two lensed components are estimated to be -1.6× 10^13 K. Thus bulk relativistic motion with a Lorentz factor less than -20 may be sufficient to avoid the inverse - Compton catastrophe.

关键词： radio continuum galaxies - polarization intraday variability - scattering refractive focusing - quasars Individual QSO 0917+624