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Vertical Scale Parameter Estimates for 48 Non-edge-on Spiral Galaxies

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chinese Journal of Astronomy and Astrophysics 2003年第6期3卷 499-504页

作者： Jun MaNational Astronomical Observatories, chinese academy of Sciences, Beijing 100012 National Astronomical Observatories CAS NAOC Beijing 100012 China

In the first paper of this series, we directly studied the mathematicalforms, symmetry of spiral structure, and the projection of galactic discs on the images, andmeasured the pitch angles of the spiral arms and inclination angles of the galactic discs for 60spiral galaxies. In this second paper, we estimate the vertical scale parameters of 48 non-edge-onspiral galaxies based on the method proposed by Peng et al. and on the results given in Paper I. Aswe know, for edge-on disc galaxies we can obtain the vertical scale parameter from the photometry,once a mathematical form is specified for the vertical light distribution. For non-edge-on galaxies,some other methods have to be used. The statistical result was that the vertical scale parameter iscomparable for edge-on and non-edge-on galaxies, although it is obtained from two very differentmethods.

关键词： galaxies: spiral galaxies galaxies: vertical scale parameter

Investigation of a New Exsolved Cu-Fe-S Phase in“Abnormal Sphalerite”

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Acta Geologica Sinica(English Edition) 1991年第1期65卷 27-36,110-111页

作者： Li Jiuling Wang Su Institute of Mineral Deposits, chinese academy of Geolgical Sciences,Beijing Beijing Laboratory of Electron Microscopy, chinese academy of Sciences, Beijing Institute of Mineral Deposits Chinese Academy of Geolgical Sciences Beijing China

A new exsolved copper-iron-sulfur phase in sphalerite has been found in the Dajing cassiterite- sulfidecopper-silver-tin deposit, Inner Mongolia, China. After investigating the optical properties, chemical composi-tion, crystal structure and exsolved Characters of the exsolved phase, the authors present important evidencefor its being a new exsolved copper-iron-sulfur phase mineral. Its formation mechenism is discussed in consider-ing heating experiments, phase equilibrium data and the geology of the deposit.

关键词： Ph Fe Abnormal Sphalerite Cu

CALCULATION FOR DEFORMATION OF THE FLEXIBLE GUIDE ON PRECISION MICROPOSITIONER

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chinese Journal of Mechanical Engineering 1999年第4期12卷 266-269页

作者： Zhou Mingbao Institute of Optics and Electronics, chinese academy of Sciences chinese Acad of Sciences China

The equations for calculating the deformation of parallelogram type flexible guide, which is caused by the external force, are derived. The correctness of these equations is verified by comparison with other research ... 详细信息

关键词： Flexible guide Elastic deformation

Molecular Gas and Dust in the Massive Star Forming Region S 233 IR

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chinese Journal of Astronomy and Astrophysics 2004年第5期4卷 440-454页

作者： Rui-Qing Mao and Qin Zeng1 Purple Mountain Observatory, chinese academy of Sciences, Nanjing 210008 2 National Astronomical Observatories, chinese academy of Sciences, Beijing 100012 Purple Mountain Observatory Chinese Academy of Sciences National Astronomical Observatories Chinese Academy of Sciences

The massive star forming region S 233 IR is observed in the molecular lines CO J = 2–1, 3–2, NH3 (1,1), (2,2) and the 870 um dust continuum. Four submillimeter continuum sources, labelled SMM 1–4, are revealed in the 870 um dust emission. The main core, SMM1, is found to be associated with a deeply embedded near infrared cluster in the northeast; while the weaker source SMM2 coincides with a more evolved cluster in the southwest. The best fit spectral energy distribution of SMM1 gives an emissivity of β = 1.6, and temperatures of 32 K and 92 K for the cold- and hot-dust components. An SMM1 core mass of 246 M☉, and a total mass of 445 M☉ are estimated from the 870 um dust continuum emission. SMM1 is found to have a temperature gradient decreasing from inside out, indicative of the presence of interior heating sources. The total outflow gas mass as traced by the CO J = 3–2 emission is estimated to be 35 M☉. Low velocity outflows are also found in the NH3 (1,1) emission. The non-thermal dominant NH3 line width as well as the substantial core mass suggest that the SMM1 core is a ``turbulent, massive dense core', in the process of forming a group or a cluster of stars. The much higher star formation efficiency found in the southwest cluster supports the suggestion that this cluster is more evolved than the northeast one. Large near infrared photometric variations found in the source PCS-IR93, a previously found highly polarized nebulosity, indicate an underlying star showing the FU Orionis type of behavior.

关键词： ISM: jets and outflows ISM: molecules ISM: dust, extinction stars:formation ISM: individual

SYNTHESIS AND CHARACTERIZATION OF NEW STABILIZERS WITH OPTIMAL MOLECULAR WEIGHT

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chinese Journal of Polymer Science 2001年第4期19卷 341-350页

作者： Jiang-qing Pan Institute of Chemistry chinese academy of Sciences, Beijing 100080 China 中科院化学所北京

Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.

关键词： preparation of stabilizer antioxidant hindered amine light stabilizer isocyanation hydrosilylation

THREEDIMENSIONAL NUMERICAL SIMULATION OF WINDINDUCED CIRCULATION IN LAKE TAIHU

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Journal of Hydrodynamics 2004年第3期16卷 341-349页

作者： LUOLian-cong QINBo-qiang NanjingInstituteofGeographyandLimnology ChineseAcademyofSciencesNanjing210008China

A three-dimensional (3-D) numerical circulation model for shallow-lake ispresented and described in detail in this paper, which employs model-splitting technique in order tocalculate water level, mean-depth velocities and horizontal and vertical velocities at differentdepth simultaneously. The results show the current circulation pattern features four eddies with twoclockwise and two anticlockwise induced by prevailing wind. Opposite wind field will lead toopposite current pattern with phase shifted by 180° The surface convergence zone is located in theupwind area and the surface divergence part in the downwind region, This results in drastic verticalmovement in the two zones and the return currents at the bottom with phase shifted by 180° fromthe surface current vectors. Thus the water level decreases significantly at the leeward side andincreases quickly at the windward part. Verification and calibration for the model were made basedon the water-level and current data observed during the 9711 Storm in Lake Taihu. The predictedresults are in satisfactory agreement with the observed data, which raises the possibility that thismodel can be used to decide the bottom current stress for sediment resuspension and also tosimulate sediment transportation. It can provide a fundamental tool to study the nutrient releasefrom bottom sediment in Lake Taihu.

关键词： numerical simulation three dimensional hydrodynamics lake taihu

BOUNDARY FEEDBACK STABILIZATION OF NONUNIFORM TIMOSHENKO BEAM WITH A TIPLOAD

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chinese Annals of Mathematics,Series B 2001年第4期22卷 485-494页

作者： YAN QINGXU, FENG DEXING Institute of Systems Science, academy of Mathematics and Systems Science, chinese academy of Sciences, Beijing 100080, China. Institute of Systems Science, academy of Mathematics and Systems Science, chinese academy of Sciences, Be Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

The boundary stabilization problem of a Timoshenko beam attached with a mass at one end is studied. First, with linear boundary force feedback and moment control simultaneously at the end attached with the load, the energy corresponding to the closed loop system is proven to be exponentially convergent to zero as time t →∞. Then, some counterexamples are given to show that, in other casest the corresponding closed loop system is, in general, not stable asymtotically, let alone exponentially.

关键词： Timoshenko beam Boundary feedback control C0 semigroups Exponential stability Multiplier method

PREPARATION AND PROPERTIES OF ETHYL-CYANOETHYL CELLULOSE/POLYACRYLIC ACID COMPOSITE FILMS WITH REFLECTION COLORS

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chinese Journal of Polymer Science 2001年第3期19卷 277-282页

作者： Yong Huang Institute of Chemistry, chinese academy of Sciences, Beijing 100080 China Laboratory of Cellulose and Lignocellulosics Chemistry Guangzhou Institute of Chemistry chinese academy of Sciences, Guangzhou 510650, China 中科院化学所北京

Ethyl-cyanoethyl cellulose [(E-CE)C]/acrylic acid (AA) becomes a cholesteric liquid crystalline solution withvivid colors when the (E-CE)C concentration is 42 wt%～52 wt%. (E-CE)C/polyacrylic acid (PAA) composites withcholesteric structure were prepared by polymerzing AA in (E-CE)C/AA liquid crystalline solutions. The layers of orderedpolymer chains in the cholesteric phase were inclined during polymerization and the degree of the inclination depended onthe polymerization temperature and the concentration of the solution before polymerization. The cholesteric structure in thecomposites could not be changed when temperature was lower than 100℃. Cross-linking of the PAA in compositesimproved their water-resistance. The cholesteric order of the composites without cross-linking was destroyed when theywhere immersed in water. The color derived from the selective reflection of the cholesteric phase of the cross-linkedcomposites turned from blue to red after the composites absorbed water. The color of the composites could be returned to theoriginal one when the absorbed water was removed from the swollen composites.

关键词： Cholesteric structure Composites Selective reflection Liquid crystalline solutions

An Ancient Solar Eclipse Record "Tian-da-yi" in the 10th Century BC

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chinese Journal of Astronomy and Astrophysics 2002年第5期2卷 391-395页

作者： Ci-Yuan LiuShaanxi Observatory, chinese academy of Sciences, Lintong 710600 Shaanxi Observatory Chinese Academy of Sciences Lintong 710600

The ancient record "Tian-da-yi" (the sky darkened greatly) is identified with the solar eclipse on May 31, 976BC. This identification is demonstrated in this paper through a palaeographic, astronomical and chronologic... 详细信息

关键词： solar eclipses - history of astronomy