共查询到20条相似文献，搜索用时 15 毫秒
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为了研究激光天文动力学空间任务概念,我们建立了CGC 2星历框架及演算法.在此框架中,我们考虑了太阳、九大行星、月球等十一个主要天体和492颗直径大于65km的小行星.我们使用后牛顿运动方程式及Runge-Kutta四阶数值方法,取的演进间距为0.01天.鉴于个人计算机的进展,此星历之演算在个人计算机上即可进行,算法及程序公开,可供研究者方便使用.在和JPL DE 405之算法比较时,我们使用DE 405星历之参数及初始值演算并将其和DE 405之差与DE 403和DE 405之差比较.比较结果,显示CGC 2星历与DE 405星历之演算结果相近.若要进一步成为独立的星历,则需重新拟合所有有效的观测数据.此公开的框架并可望在未来有新数据时供研究者改进. 相似文献
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N2 2P fluorescent intensity was monitored as a function of incident photon energy from 40 to 70 eV. A structure was seen near 52.2 eV. This feature is attributed to the scattering of photoelectrons originating from the N2 2σg molecular orbital with a binding energy of about 37.7 eV. The kinetic energy of these photoelectrons corresponds to the peak of the 2P excitation cross section at 14.5 eV. 相似文献
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CGC2星历框架 总被引：1，自引：1，他引：0
为了研究激光天文动力学空间任务概念，我们建立了CGC2星历框架及演算法。在此框架中，我们考虑了太阳，九大行星，月球等十一个主要天体和492颗直径大于65km的小行星。我们使用后牛顿运动方程式及Rnge-Kutta四阶数值方法，取的演进间距为0．01天。鉴于个人计算机的进展，此星历之演算在个人计算机上即可进行，算法及程序公开，可供研究者方便使用。在和JPL DE405之算法比较时，我们使用DE 405星历之参及初始值学演算并将其和DE 405之差与DE 403和DE405之差比较。结果显示，显示CGC2星历与DE405星历之演算结果相近。若要进一步成为独立的星历，则需重新拟合所有有效的观测数据。此公开的框架并可望在未来有新数据时供研究者改进。 相似文献
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In the problem of 2+2 bodies in the Robe’s setup, one of the primaries of mass m*1m^{*}_{1} is a rigid spherical shell filled with a homogeneous incompressible fluid of density ρ
1. The second primary is a mass point m
2 outside the shell. The third and the fourth bodies (of mass m
3 and m
4 respectively) are small solid spheres of density ρ
3 and ρ
4 respectively inside the shell, with the assumption that the mass and the radius of third and fourth body are infinitesimal.
We assume m
2 is describing a circle around m*1m^{*}_{1}. The masses m
3 and m
4 mutually attract each other, do not influence the motion of m*1m^{*}_{1} and m
2 but are influenced by them. We also assume masses m
3 and m
4 are moving in the plane of motion of mass m
2. In the paper, the equations of motion, equilibrium solutions, linear stability of m
3 and m
4 are analyzed. There are four collinear equilibrium solutions for the given system. The collinear equilibrium solutions are
unstable for all values of the mass parameters μ,μ
3,μ
4. There exist an infinite number of non collinear equilibrium solutions each for m
3 and m
4, lying on circles of radii λ,λ′ respectively (if the densities of m
3 and m
4 are different) and the centre at the second primary. These solutions are also unstable for all values of the parameters μ,μ
3,μ
4, φ, φ′. Such a model may be useful to study the motion of submarines due to the attraction of earth and moon. 相似文献
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将近140亿年之前——确切地说,是137．7亿年,上下不超过5900万年——据认为,我们所在的这个宇宙就是在那个时候,以一场不寻常的爆发“出场”的。在最初的一瞬间（约10^-35秒到10^-33秒）,宇宙以指数形式极速膨胀,其膨胀幅度之大,甚至远远超过了我们现在最好的望远镜的视界。 相似文献
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2011年10月4日瑞典皇家科学院宣布。将2011年诺贝尔物理学奖授予美国科学家索尔·珀尔马特、拥有美国和澳大利亚双重国籍的科学家布赖恩·施密特以及美国科学家亚当·里斯,以表彰他们在天体物理学方面的卓越研究成果——发现宇宙加速膨胀。 相似文献
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F.C. Fehsenfeld 《Planetary and Space Science》1977,25(2):195-196
The reactions of atomic nitrogen with O+2 and atomic oxygen and atomic nitrogen with NO+· H2O and NO+2 have been measured at 296 K. The rate constants are reported and the implication of the measurements to atmospheric ion chemistry is discussed. 相似文献
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XinJieMao Jiang－TaoSu 《中国天文和天体物理学报》2001,1(5):406-410
1 INTRODUCTIONFor the behavior of a molecular cloud in subsonic collision with another, Mao et al. (1992)have obtained simplified one-dimension traveling wave solutions for a plane-parallel s1ab. Chang-ing the sign in the transformation of variables in their case, we have the fOllowing results,1 rP = 2 l W op -- 1, (1)1 r =v = -- j W -- ry 1. (2)2 {V(N M)' 2z 2t -- W 1. (2)In Eq. (1), p increases with increasing t. Instability is expected to occur in strongly perturbedmolecular… 相似文献
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Jie Jiang Jing-Xiu Wang National Astronomical Observatories Chinese Academy of Sciences Beijing 《中国天文和天体物理学报》2006,6(2):227-236
Using the Chebyshev-tau method, the generation of oscillatory non-axisymmetric stellar magnetic fields by the α2-dynamo is studied in spherical geometry. Following the boundary conditions given by Schubert & Zhang, the spherical α2-dynamo consists of a fully convective spherical shell with inner radius ri and outer radius ro. A comparison of the critical dynamo numbers of axisymmetric and φ-dependent modes for different thicknesses of the convective shell and different α-profiles leads to the following qualitative results: (i) when the angular factor of α-profile is sinn θcosθ (n = 1,2,4) the solutions of the α2-dynamo are oscillatory and non-axisymmetric, (ii) the thinner the convective shell, the more easily is the non-axisymmetric mode excited and the higher is the latitudinal wave number, (iii) the thickness of the outer convective shell has an effect on the symmetries of the magnetic fields. 相似文献
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XUE Zhuhe 《中国科学院上海天文台年刊》2003,(1)
上海天文台佘山 2 5m观测站S2 -PT终端系统用于甚长基线干涉测量 (VLBI)实验。它在实验中按不同的模式将实验数据记录在录像带上。新一代S2FS控制软件使用一个观测纲要文件和一个过程控制文件在FS(FieldSystem)软件下控制S2终端系统 相似文献
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天文用2K×2K高速CMOS相机的研制与测试结果 总被引：3，自引：0，他引：3
高性能CMOS成像器件的技术近年来发展迅速,与长期在天文观测中占统治地位的CCD器件相比,CMOS在读出速度、功耗、空间应用的可靠性等方面具有一定的优势。为了探索CMOS成像器件在天文领域中的应用,我们以Fillfactory公司最新的高速、大面阵CMOS芯片LUPA 4000为基础,研制了一台天文相机并对其进行了测试。本文简要介绍了CMOS成像器件的概述,相机软、硬件系统的组成,以及在实验室条件下得到的读出噪声、增益、线性和增益等若干测试结果。 相似文献
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薛祝和 《中国科学院上海天文台年刊》2003,(24):118-121
上海天台余山25m观测站S2—PT终端系统用于甚长基线干涉测量(VLBI)实验。它在实验中按不同的模式将实验数据记录在录像带上。新一代S2FS控制软件使用一个观测纲要件和一个过程控制件在FS(Field System)软件下控制S2终端系统。 相似文献
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在国家科技部，云南省，及中国科学院的支持下，2m级天文望远镜建设项目于2000年12月正式启动，在本文中，我们首先简要地介绍该项目的台址：丽江高美古；其次，就该项目的情况给出详尽的介绍；最后，就该望远镜未来的一些计划进行了讨论。 相似文献
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F. Cachucho P. M. Cincotta S. Ferraz-Mello 《Celestial Mechanics and Dynamical Astronomy》2010,108(1):35-58
The theory of diffusion in many-dimensional Hamiltonian system is applied to asteroidal dynamics. The general formulation
developed by Chirikov is applied to the Nesvorny-Morbidelli analytic model of three-body (three-orbit) mean-motion resonances
(Jupiter-Saturn-asteroid). In particular, we investigate the diffusion along and across the separatrices of the (5, −2, −2) resonance of the (490) Veritas asteroidal family and their relationship to diffusion
in semi-major axis and eccentricity. The estimations of diffusion were obtained using the Melnikov integral, a Hadjidemetriou-type
sympletic map and numerical integrations for times up to 108 years. 相似文献
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《天文和天体物理学研究(英文版)》2020,(7)
We report a multi-wavelength study of two evolved planetary nebulae(PNs) M 2–55 and Abell 2.Deep optical narrow-band images([O III], Hα, and [N II]) of M 2–55 reveal two pairs of bipolar lobes and a new faint arc-like structure. This arc-shaped filament around M 2–55 appears as a well-defined boundary from southwest to southeast, strongly suggesting that this nebula is in interaction with its surrounding interstellar medium. From the imaging data of Wide-field Infrared Survey Explorer(WISE) all-sky survey,we discovered extensive mid-infrared halos around these PNs, which are approximately twice the size of their main nebulae seen in the visible. We also present a mid-resolution optical spectrum of M 2–55, which shows that it is a high-excitation evolved PN with a low electron density of 250 cm~(-3). Furthermore, we investigate the properties of these nebulae from their spectral energy distributions(SEDs) by means of archival data. 相似文献
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Laboratory transmission IR spectra of relatively thick films (up to 500 m) of mixed H2O and SO2 ices were measured at several temperatures between 10 and 130 K in the range 5000-450 cm–1. In addition to the strong features due to crystalline SO2 the spectra reveal bands at 3668 cm–1, 3634 cm–1 (with some structure) and 3300 cm–1 which are identified with H2O in SO2 environment. Also, there is no overlap between any of the H2O bands with the 3584 cm–1 band of SO2 at any temperature in the above range. The implication of this result is that H2O, if present on Io, must be far less than 1 part in 105 SO2. 相似文献