检索结果-南通市图书馆

XMM-Newton observation of the eclipsing binary Algol

Research in Astronomy and astrophysics 2011年第4期11卷 457-470页

作者： Xue-Juan Yang Fang-Jun Lu Bemd Aschenbach Li Chen Faculty of Materials Optoelectronics and Physics Xiangtan University Xiangtan 411105China particle astrophysics Center Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Max-Planck-Institut fur Extraterrestrische Physik 85741 Garching Germany Department of Astronomy Beijing Normal University Beijing 100875 China

We present an XMM-Newton observation of the eclipsing binary Algol which contains an X-ray dark B8V primary and an X-ray bright K2.V secondary. The observation covered the optical secondary eclipse and captured an X-ray flare that was eclipsed by the B star. The XMM-Newton European Photon Imaging Camera and Reflection Grating Spectrometer spectra of Algol in its quiescent state are described by a two-temperature plasma model. The cool component has a temperature around 6.4× 106 K while that of the hot component ranges from 2.to 4.0× 107 K. Coronal abundances of C, N, O, Ne, Mg, Si and Fe were obtained for each component for both the quiescent and the flare phases, generally with upper limits for S and Ar, and upper limits for C, N, and O from the hot component. F-tests show that the abundances do not need to be different between the cool and the hot component and between the quiescent and the flare phase with the exception of Fe. Although the Fe abundance of the cool component remains constant at -0.14, the hot component shows an Fe abundance of -0.2., which increases to -0.44 during the flare. This increase is expected from the chromospheric evaporation model. The absorbing column density NH of the quiescent emission is 2.5 - 102. cm-2. while that of the flare-only emission is significantly lower and consistent with the column density of the interstellar medium. This observation substantiates earlier suggestions of the presence of X-ray absorbing material in the Algol system.

关键词： stars abundance -- star binaries eclipsing -- stars flare -- stars indi-vidual Algol

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

EI NIO PHENOMENON AND EXTENDED ASSOCIATE PATTERN ANALYSIS

引用

Journal of Hydrodynamics 2004年第1期16卷 90-100页

作者： CUIMao-chang MOJun QIAOFang-li instituteofOceanology ChineseAcademyofSciences.Qingdao266071China／KeyLaboratoryofMarineScienceandNumericalmodelingTheFirstInstituteofOceanographyStateOceanicAdministrationQingdao266061China. instituteofOceanology ChineseAcademyofSciences.Qingdao266071China keylaboratoryofMarineScienceandNumericalmodeling TheFirstInstituteofOceanographyStateOceanicAdministrationQingdao266061China

To study the causes of El Nino Phenomenon the Extended Associate PatternAnalysis (EAPA) is set up with monthly sea surface wind stress and precipitation besides Sea LevelPressure (SLP) and Sea Surface Temperature (SST) in or over the Pacific and related seas since 1979in present paper. The results show that El Nino Phenomenon means a SST redistribution, coveringalmost the whole Pacific that needs a huge amount of energy provided by air-sea interaction in themost Pacific regions; It is the wester burst and wind convergence, coming from meddle latitudesdirectly, instead of Kelvin waves that produce the strong SST warm signal in Nino regions; Twonegative SLP anomalies in middle of the North and South Pacific, most likely produced by the averageair pressure decreasing effect of explosive cyclones through precipitation, and the positive SLPanomaly o-ver the Asia-Australia land bridge, coming mainly from the south hemisphere with a littleinfluence from the Asian continent, are the three major causes for El Nino onset, they work togetherto produce anomalous wind convergence in Nino regions and wester burst in middle of the North andSouth Pacific that result in a warm tongue and cold pincers gearing together; Basically, during itsearly stage the ocean is forced by the atmosphere, while during its late stage the atmosphere isforced by the ocean.

关键词： extended associate pattern analysis (EAPA) El nino phenomenon

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A preliminary study on fingerprinting approach in marine sediment dynamics with the rare earth elements

引用

Acta Oceanologica Sinica 2010年第4期29卷 62-77页

作者： ZHOU Xiaojing LI Anchun JIANG Fuqing MENG Qingyong key laboratory of Marine Geology ＆ Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Graduate School of the chinese academy of sciences Beijing 100039 China

Locating the quantitized natural sediment fingerprints is an important work for marine sediment dynamics *** total of 146 sediment samples were collected from the Shelf of the East china Sea and five rivers,including Huanghe （Yellow）,Changjiang （Yangtze）,Qiantang,Ou and Min *** sediment grain size and the contents of rare earth elements （REEs） were measured with laser particle size analyzer and ICP-MS *** results show that absolute REE content （ΣREE） and the concentration ratio of light REEs to heavy REEs （L/HREE） are different in the sediments among those *** are {2.er REE contents in being less than 2.m and 2.31 μm fractions in the Changjiang Estuary surface *** REE contents of bulk sediment are dominated by the corresponding values of those leading *** of sediment is {2.er close to the estuaries and declines seaward on the inner shelf of the East china Sea （ECS）.The L/HREE ratio has a tendency of increase southward from 2. ？ *** conditions plays a predominate role on spacial distributions of the surficial sediment’s REE *** some situations,the currents tend to remove the coarser light grains from initial populations,as well as the deposit of the finer heavy mineral *** other situations,the currents will change the ratio of sediment constituents,such as ratio between silts and clays in the *** a result,the various values of REE or L/HREE ratio in different bulk sediments are more affected by the change of size-fractions than source *** the long-term stable hydrodynamic environment,i.e.,the East china Sea Shelf,new sediment transport model based on the size and density gradation concept may help to understand the spatial distribution patterns of REE parameters.

关键词： rare earth elements fingerprints East china Sea Shelf sediment transport

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Degradation of 4-chlorophenol in aqueous solution by γ-radiation and ozone oxidation

引用

Science china Chemistry 2006年第2期49卷 186-192页

作者： HU Jun1, WANG Jianlong1,2.& CHEN Rong1 1. laboratory of Environmental Technology, institute of Nuclear {2. Technology, Tsinghua University, beijing 100084, china 2. State key Joint laboratory of Environmental Simulation and Pollution Control, Tsinghua University, beijing 100084, china Correspondence should be addressed to Wang Jianlong 1. laboratory of Environmental Technology Institute of Nuclear Energy Technology Tsinghua University Beijing 100084 China 2. State key Joint laboratory of Environmental Simulation and Pollution Control Tsinghua University Beijing 100084 China

The degradation of 4-chlorophenol (4-CP) by using gamma rays generated by a 60Co source in the presence of O3 was investigated. The radiolysis of 4-CP and the kinetics of 4-CP min-eralization were analyzed based on the determination of total organic carbon (TOC). The influence of initial 4-CP concentration and the free radicals scavengers (such as NaHCO3 and t-butanol) on the 4-CP degradation was also studied. The results showed that when the radiation rate was 336 Gy·min?1, 4-chlorophenol at concentration of 10 mg·L?1 could be completely degraded at the radiation dose of 2.kGy. The degradation of 4-chlorophenol could be described by a first-order reaction model, the rate constant of 4-CP degradation by combined ozonation and radiation was 0.1016 min?1, which was 2.4 times higher than the sum of radiation (0.02.4 min?1) and ozonation (0.0137 min?1). It re-vealed that the combination of radiation and ozonation resulted in synergistic effect, which can re-markably increase the degradation efficiency of 4-CP.

关键词： radiolysis, 4-chlorophenol, priority pollutant, degradation, O3, synergistic effect, kinetics.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

TRANSIENT EFFECT OF A BOGER FLUID FLOWING AROUND A CONFINED CYLINDER

引用

chinese Journal of Polymer Science 2001年第4期19卷 377-384页

作者： Xian-feng Li Huai-tian Bu De-lu Zhao State key laboratory of Polymer Physics and Chemistry Center for Molecular Science,{2. of Chemistry, chinese academy of sciences, beijing 100080, china chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China

This paper is concerned with the numerical simulation of the transient effect of an inertialess Boger flow past a confined circular cylinder and the comparison of predictions with particle image velocimetry (PIV) measurements given by Shiang et al.. Dynamic simulation based on the Oldroyd-B constitutive model was carried out using a Lagrangian-Eulerian algorithm. The evolution of velocity field was obtained for the flow at two Deborah (De) numbers, i.e. De = 1.2.and 3.0. At low De, the flow reached steady state rapidly, and showed a symmetric flow regime. However, at high De, the time required to reach steady flow behind the cylinder increased significantly, and the distribution of the velocity field appears to be asymmetric with respect to the stagnation line. Fairly good agreement between the numerical results and the experimental observations is reported. It can be concluded that both the experimental measurements and the present simulations indicate that the elasticity of the polymeric flow strongly affect the flow regime of viscoelastic flow around a confined cylinder.

关键词： transient effect flow around a cylinder Lagrangian-Eulerian algorithm Oldroyd-B model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A comparative analysis on two solar proton events

引用

chinese Science Bulletin 2007年第1期52卷 47-51页

作者： LE GuiMing1,2.3,4, HAN YanBen2.& ZHANG YiJun3 1 key laboratory of Radiometric Calibration and Validation for Environmental Satellites, {2. Meteorological Administration, beijing 100081, {2. 2.National Astronomical Observatories, chinese academy of sciences, beijing 100012. {2. 3 chinese academy of Meteorological sciences, {2. Meteorological Administration, beijing 100081, {2. 4 National Center for Space Weather, {2. Meteorological Administration, beijing 100081, {2. key laboratory of Radiometric Calibration and Validation for EnvironmentalSatellites China Meteorological Administration Beijing 100081 China

This paper presents a comparative analysis on the two Solar Proton Events (SPE), which occurred on 14 July 2.00 (Bastille Day) and 2. October 2.03 (2.OCT03) respectively. It is found that although the peak flux of the latter seemed to be greater than that of the former based on geostationary observations, the maximum intensities of the energetic protons (>10 MeV and 30 MeV) during the Bastille Day event were all higher than those of the 2.OCT03 event according to the interplanetary observations. Further analysis indicated that the quantity of the seed particles, which could be accelerated to the energies exceeding 10 and 30 MeV by the Coronal Mass Ejection (CME)-driven shock on 14 July 2.00, was far larger than that of the 2.OCT03 event. In the Bastille Day case, when the CME approached to the height around 14 R⊙, the CME-driven shock would reach its maximum capacity in accelerating the solar en- ergetic protons (>100 MeV). In contrast, on 2. October 2.03, when CME approached to the height about 58R⊙, the CME-driven shock reached its highest potential in accelerating the solar energetic protons of the same category. At this moment, the peak flux (>100 MeV) was about 155 pfu, which was much lower than 355 pfu measured on 14 July 2.00. This demonstrated that in the Bastille Day event, the quantity of the seed particles, which could be accelerated to the energy beyond 100 MeV, was significantly larger than its counterpart in the 2.OCT03 case. Therefore, the peak flux of an SPE event depends not only on the interplanetary intensity of the solar energetic particles, but also on the velocity of the associated CME-driven shock, and the quantity of the seed particles as well as on the interplanetary magnetic en- vironment. This paper also reveals that the magnetic sheath associated with ICME on 2. October 2.03 captured a large number of solar energetic protons, including those having energy greater than 100 MeV.

关键词：太阳质子 CME 太阳耀斑太阳系

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interaction between electromagnetic waves and energetic particles by a realistic density model

引用

Science china(Technological sciences) 2010年第9期53卷 2552-2557页

作者： HE YiHua1,2.CHEN LiangXu1,XIAO FuLiang1 & YANG Chang1 1 School of Physics and Electronic sciences,Changsha University of Science and Technology,Changsha 410004,china 2.State {2. laboratory of Space Weather,chinese academy of sciences,beijing 100190,china 1. School of Physics and Electronic sciences Changsha University of Science and Technology Changsha 410004 China2. State Key Laboratory of Space Weather Chinese Academy of Sciences Beijing 100190 China

Using a realistic density model,we present a first study on the interactions between electromagnetic waves and energetic particles in the inner *** calculations show that as the latitude λ increases,the number density ne increases,and resonant frequency range moves to lower pitch *** L-mode/electron and L-mode/proton interactions,the pitch angle diffusion dominates over the momentum *** indicates that L-mode waves are primarily responsible for pitch angle *** R-mode/electron interaction,the momentum diffusion is found to be comparable to the pitch angle diffusion,implying that R-mode waves can play an important role in both pitch angle scattering and stochastic acceleration of *** R-mode/proton interaction,diffusion coefficients locate primarily below pitch angle 60° and increase as kinetic energy increases,suggesting that R-mode waves have potential for pitch angle scattering of {2.ly energetic (~1 MeV) protons but cannot efficiently accelerate protons.

关键词： wave-particle interaction energetic particles resonant frequency pitch angle and momentum diffusion density model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Solid State Polymer Electrolytes for Dye-sensitized Solar Cell

引用

复旦学报（自然科学版） 2007年第5期46卷 660-661页

作者： Xiong Yin1,2. Wanchun Xiang1,2. Xurui Xiao1, Yuan Lin1, Shibi Fang1(1.key laboratory of Photochemistry, {2. of Chemistry, chinese academy of sciences, beijing 100080, china 2.Graduate School of chinese academy of sciences, beijing 100039, china) institute of Chemistry Chinese Academy of Sciences Key Laboratory of Photochemistry Chinese Academy of Sciences Beijing 100080

1 Introduction Over the past decade,Dye-sensitized solar cells (DSSCs) have been intensively investigated as potential alternatives to conventional inorganic photovoltaic devices due to their low production cost and high energy conversion[1-4]. This type of solar cell has achieved an impressive energy conversion efficiency of over 10%,whose electrolyte is a voltaic organic liquid solvent containing iodide/triiodide as redox ***,the use of a liquid electrolyte brings difficulties in the practi...

关键词： dye-sensitized solar cell chemically cross-linked gel polymer electrolyte quaternization reaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic evolution of outer radiation belt electrons driven by superluminous R-X mode waves

引用

Science china(Technological sciences) 2010年第10期53卷 2734-2738页

作者： XIAO FuLiang1,2. CHEN LiangXu1, HE YiHua1 & YANG Chang1 1 School of Physics and Electronic sciences, Changsha University of Science and Technology, Changsha 410004, china 2.State {2. laboratory of Space Weather, chinese academy of sciences, beijing 100190, china 1. School of Physics and Electronic sciences Changsha University of Science and Technology Changsha 410004 China2. State Key Laboratory of Space Weather Chinese Academy of Sciences Beijing 100190 China

We present initial results on the temporal evolution of the phase space density (PSD) of the outer radiation belt energetic electrons driven by the superluminous R-X mode waves. We calculate diffusion rates in pitch angle and momentum assuming the standard Gaussian distributions in both wave frequency and wave normal angle at the location L=6.5. We solve a 2. momentum-pitch-angle Fokker-Planck equation using those diffusion rates as inputs. Numerical results show that R-X mode can produce significant acceleration of relativistic electrons around geostationary orbit,supporting previous findings that superluminous waves potentially contribute to dramatic variation in the outer radiation belt electron dynamics.

关键词： wave-particle interaction superluminous R-X waves phase space density evolution radiation belt electrons

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Simulation and Experimental Validation on Gas-Solid Two Phase Flow in the Riser of a Dense Fluidized Bed

引用

Journal of Thermal Science 2009年第2期18卷 137-141页

作者： Xue-yao Wang Fan Jiang Xiang Xu Sheng-dian Wang Bao-guo Fan Yun-han Xiao key laboratory of Advanced {2. and Power, chinese academy of sciences (institute of Engineering Thermophysics) beijing 100190 key laboratory of Advanced {2. and Power Chinese Academy of Sciences (Institute of Engineering Thermophysics) Beijing 100190 China

Gas-solid flow in dense CFB (circulating fluidized bed)) riser under the operating condition, superficial gas 15.5m/s and solid flux 140 kg/m2. using Geldart B particles (sand) was investigated by experiments and CFD (computationalfluid dynamics) simulation. The overall and local flow characteristics are determined using the axialpressure profiles and solid concentration profiles. The cold experimental results indicate that the axial solid concentration distribution contains a dilute region towards the up-middle zone and a dense region near the bottomand the top exit zones. The typical core-annulus structure and the back-mixing phenomenon near the wall of theriser can be observed. In addition, owing to the key role of the drag force of gas-solid phase, a revised drag forcecoefficient, based on the EMMS ({2.-minimization multi-scale) model which can depict the heterogeneouscharacter of gas-solid two phase flow, was proposed and coupled into the CFD control equations. In order to findan appropriate drag force model for the simulation of dense CFB riser, not only the revised drag force model butsome other kinds of drag force model were used in the CFD. The flow structure, solid concentration, clustersphenomenon, fluctuation of two phases and axial pressure drop were analyzed. By comparing the experimentwith the simulation, the results predicted by the EMMS drag model showed a better agreement with the experimentalaxial average pressure drop and apparent solid volume fraction, which proves that the revised drag forcebased on the EMMS model is an appropriate model for the dense CFB simulation.

关键词： riser gas-solid flow drag force EMMS model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：