共查询到20条相似文献，搜索用时 656 毫秒
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根据化学家诺贝尔的遗嘱,从1901年开始颁发多项诺贝尔奖金,其中之一是诺贝尔物理学奖。这个奖项从第一次颁奖至今已整整过去100年了。在这100年中,有8项天体物理学研究成果获得了6个年份的诺贝尔物理学奖,这些年份是1936年、1967年、1974年、1978年、1983年和1993年,其中1974年和1983年各有两项。 相似文献
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(Meeting under Consideration as IAU万ymPosia/仁0王IOqu又a)名称开会时间开会地点借星和太阳系其它天体动力学演化与相互关系基本恒星量定标含有过量重元素的冷星经度零点紫外和X射线光谱学星系中亮星和星协天体测量双星1984年5月1984年春或初夏1984年6月(12、15日?)1984年7月1984年1984年9月、10月1984年1984年10月1985年9月1985年1985年11月1985年1985年1985年1985年12月意大利,罗马 联系人A.Carusi(意)意大利法国,英国,华盛顿希腊西德,斯特拉斯堡格林尼治班贝格恒星视向速度宇宙大尺度结构演化类星体缺氢恒星及有关天体恒星辐射… 相似文献
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利玛窦（意大利文：Matteo Ricci,1552年10月6日-1610年5月11日）,是耶稣会意大利传教士,1582年（明万历十年）来到澳门,次年利玛窦获准与罗明坚神父入居广东肇庆,1601年（明万历二十九年）抵达北京,1610年（明万历三十八年）去世。他在中国传教、生活了二十八年,将许多西方的天文学、地理学和数学知识传译到中国。 相似文献
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在2007年12月20日的第62届联合国会员大会上,联合国宣布2009年为国际天文年。决议由伽利略的故乡意大利提交。2009年国际天文年由国际天文学联合会及联合国教科文组织共同主办。 相似文献
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简单介绍了灰色拓扑理论的原理,以1944—2008年各年的太阳黑子数年均值为基础,利用灰色拓扑预测方法建立了灰色拓扑预测模型群,并应用该模型群对第24、25和26太阳活动周自2009年到2039年共30 yr的太阳黑子数年均值进行了预测.预测结果表明,太阳黑子数极大年将可能出现在2014年、2023年和2033年,峰值分别为90、110和130,推测将在2017年、2025年和2039年达到极小值,极小值分别为20、20和10. 相似文献
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3C 345和3C 273的光变分析 总被引：1，自引：0，他引：1
用结构函数法,对两个经典的blazar 3C 273和3C 345的22 GHz、37 GHz和光学波段的数据进行了周期分析.结果显示,3C 273的周期性比较明显,22 GHz经分析存在7.0年和14.7年的周期,37 GHz存在7.2年和14.5年的周期,同时它的光学波段可能存在0.7年和8.7年的周期.3C 345的37 GHz存在比较明显的8.8年的周期,22 GHz和光学波段分别存在不太明显的9.3年和10.2年的周期. 相似文献
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Marcello Romano 《Celestial Mechanics and Dynamical Astronomy》2008,100(3):181-189
The exact analytic solution is introduced for the rotational motion of a rigid body having three equal principal moments of
inertia and subjected to an external torque vector which is constant for an observer fixed with the body, and to arbitrary
initial angular velocity. In the paper a parametrization of the rotation by three complex numbers is used. In particular,
the rows of the rotation matrix are seen as elements of the unit sphere and projected, by stereographic projection, onto points
on the complex plane. In this representation, the kinematic differential equation reduces to an equation of Riccati type,
which is solved through appropriate choices of substitutions, thereby yielding an analytic solution in terms of confluent
hypergeometric functions. The rotation matrix is recovered from the three complex rotation variables by inverse stereographic
map. The results of a numerical experiment confirming the exactness of the analytic solution are reported. The newly found
analytic solution is valid for any motion time length and rotation amplitude. The present paper adds a further element to
the small set of special cases for which an exact solution of the rotational motion of a rigid body exists. 相似文献
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A. I. Neishtadt D. J. Scheeres V. V. Sidorenko P. J. Stooke A. A. Vasiliev 《Celestial Mechanics and Dynamical Astronomy》2003,86(3):249-275
Reactive torques, due to anisotropic sublimation on a comet nucleus surface, produce slow variations of its rotation. In this paper the secular effects of this sublimation are studied. The general rotational equations of motion are averaged over unperturbed fast rotation around the mass center (Euler-Poinsot motion) and over the orbital comet motion. We discuss the parameters that define typical properties of the rotational evolution and discover different classifications of the rotational evolution. As an example we discuss some possible scenarios of rotational evolution for the nuclei of the comets Halley and Borrelly. 相似文献
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In this paper the tidal phenomena on the Earth are concisely specified, including solid tides, ocean tides and atmospheric tides due to the luni-solar tide-generating force, and the Earth pole tide due to the motion of the Earth's rotation axis (polar motion); as well as their effects on the Earth rotation. The outcomes of scientific researches of Chinese astronomers on these topics are described in some detail. These researches deal with the mechanisms responsible for tidal effects on the earth rotation, and on the measurements of the Earth rotation parameters. Finally, the effects discovered by Chinese researchers on the measurements of the period and change in period of pulsars are discussed. These effects are very small in magnitude but not negligible. 相似文献
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Accurate Analytical Calculation of Effects of Rorations of the Central Planet on a Staellite's Orbit
Sergey M. Kudryavtsev 《Celestial Mechanics and Dynamical Astronomy》1997,67(2):131-144
Satellite orbital perturbations due to many rotations of the planet-fixed reference frame are calculated by a general analytical
method. For the International Terrestrial Reference Frame (ITRF) the effects of the Earth irregular rotation, precession,
nutation, and polar motion are considered. Gravity coefficients of the Earth potential expansion are expressed in an inertial
Celestial Reference Frame (CRF) as functions of the set of standard constant coefficients derived in the ITRF and of the rotation
angles between the CRF and ITRF. The analytical motion theory uses time dependent gravity coefficients, and the Lagrange motion
equations are integrated in the CRF, as it is done by numerical methods. Comparison of the proposed analytical method with
a numerical one is presented. Motion of the ETALON-1 geodetic satellite perturbed by the geopotential (36*36) and by the full
effects of the Earth irregular rotation, precession, nutation and polar motion is predicted. The r.m.s. difference between
the satellite's coordinates calculated by both methods over a year interval is 2 cm.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Marcello Romano 《Celestial Mechanics and Dynamical Astronomy》2008,101(4):375-390
New exact analytic solutions are introduced for the rotational motion of a rigid body having two equal principal moments of
inertia and subjected to an external torque which is constant in magnitude. In particular, the solutions are obtained for
the following cases: (1) Torque parallel to the symmetry axis and arbitrary initial angular velocity; (2) Torque perpendicular
to the symmetry axis and such that the torque is rotating at a constant rate about the symmetry axis, and arbitrary initial
angular velocity; (3) Torque and initial angular velocity perpendicular to the symmetry axis, with the torque being fixed
with the body. In addition to the solutions for these three forced cases, an original solution is introduced for the case
of torque-free motion, which is simpler than the classical solution as regards its derivation and uses the rotation matrix
in order to describe the body orientation. This paper builds upon the recently discovered exact solution for the motion of
a rigid body with a spherical ellipsoid of inertia. In particular, by following Hestenes’ theory, the rotational motion of
an axially symmetric rigid body is seen at any instant in time as the combination of the motion of a “virtual” spherical body
with respect to the inertial frame and the motion of the axially symmetric body with respect to this “virtual” body. The kinematic
solutions are presented in terms of the rotation matrix. The newly found exact analytic solutions are valid for any motion
time length and rotation amplitude. The present paper adds further elements to the small set of special cases for which an
exact solution of the rotational motion of a rigid body exists. 相似文献
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Numerical determination of stability regions for orbital motion in uniformly rotating second degree and order gravity fields 总被引：3，自引：0，他引：3
W. Hu 《Planetary and Space Science》2004,52(8):685-692
The stability of orbital motion about a uniformly rotating arbitrary second degree and order gravity field is investigated. A normalized form of the equations of motion are derived and analyzed. A numerical stability criteria is proposed and used to evaluate the stability of initially near-circular orbits in the equatorial plane of the body. Regions of stable and unstable motion are clearly delineated, and are seen to be strongly related to resonances between the mean motion and the body rotation rate. 相似文献
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根据空间大地测量结果建立的中国地壳构造块体的运动模型 总被引：2，自引：0，他引：2
本文利用空间大地测量的结果初步建立了中国地壳各构造块体的运动模型,该模型与由地质资料建立的地质学模型相比呈现较好的一致性,反映了中国及邻近地区的板块、亚板块和活动构造块体的水平运动特征和趋势。 相似文献
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Modeling of major martian magnetic anomalies: Further evidence for polar reorientations during the Noachian 总被引：1，自引：0，他引：1
Maps of the vector components of the Mars crustal magnetic field are constructed at the mapping altitude (360 to 410 km) using a selected set of data obtained with the Mars Global Surveyor magnetometer during 2780 orbits of the planet in 1999. Forward modeling calculations are then applied to six relatively strong and isolated, dominantly dipolar, magnetic anomalies for the primary purpose of estimating bulk directions of magnetization. Assuming that the magnetizing field was a (dipolar) core dynamo field centered in the planet, paleomagnetic pole positions are calculated for the six primary source bodies together with that for a seventh anomaly analyzed earlier. In agreement with several previous studies, it is found that six of the seven pole positions are clustered in what is now the northern lowlands in a region centered northwest of Olympus Mons (mean pole position: 34°±10° N, 202°±58° E). Assuming that the dynamo dipole moment vector was approximately parallel to the rotation axis, the modeling results therefore suggest a major reorientation of Mars relative to its rotation axis after magnetization was acquired. Such a reorientation may have been stimulated by internal mass redistributions associated with the formation of the northern lowlands and Tharsis, for example. A comparison of the mean paleo (magnetic) equator to the global distribution of crustal fields shows that magnetic anomalies tend to occur at low paleolatitudes. The same appears to be true for the Noachian-aged valley networks, which exhibit a broad spatial correlation with the magnetic anomalies. A possible interpretation is that the formation of magnetic anomalies and the valley networks was favored in the tropics where melting of water ice and snow was a stronger source of both surface valley erosion and groundwater recharge during the earliest history of the planet. This would be consistent with models in which hydrothermal alteration of crustal rocks played a role in producing the unusually strong martian magnetic anomalies. 相似文献
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R. T. Gangadhara 《Astrophysics and Space Science》1995,232(2):327-336
Pulsars accelerate the charged particles moving along their magnetic field lines due to their rapidly spinning motion. Particles gain maximum energy from pulsars within the light cylinder when they are moving along the field lines perpendicular to the rotation velocity. In pulsars with non-aligned rotation and magnetic axes, the production of two intense and sharp pulses (main pulse and interpulse) separated by 180° longitude occur at the two regions near the light cylinder where the rotation velocity is perpendicular to the magnetic field. Since the radiating particles move radially along the relativistically compressed magnetic field lines, the observer in the stationary frame receives beamed and transversely compressed radiation pulse. Near the light cylinder position angle varies smoothly during pulsar rotation in a way as Radhakrishnan and Cook (1969) expect its variation near the magnetic pole, as the field lines experience relativistic compression in the direction of rotation. The motion of two charge species along the field lines produce orthogonal modes at each pulse longitude. 相似文献
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简要说明了天文地球动力学范畴内所研究的潮汐现象，包括由日月引潮力引起的固体潮、海洋潮、大气潮和由于地球自转轴的极移引起的极潮，以及这些潮汐对地球自转和地球自转的测量产生的效应。重点阐述中国天文学界在这一领域里的研究成果。这些研究涉及潮汐影响地球自转的机制，也就是各种潮汐效应与极移、自转速率变化和章动的关系，包括构建这类关系的理论模型，分析潮汐对它们的影响，利用中国古代丰富的天象记录计算地球自转的长期减慢，计算弹性或滞弹地球的洛夫数，依据某一地球模型计算潮汐效应或章动序列等等。研究也涉及在测量地球自转参数的不同技术中各种潮汐效应对测量结果产生的影响及其改正，并涉及与潮汐有关的观测方法的优化和数据处理过程的改进。最后介绍了中国学者所发现的脉冲星的周期和周期变率测量中的潮汐效应，尽管它们的量级甚微，但不容忽视。 相似文献