太阳黑子数月平均变化的长期行为的可预报性

本用非线性动力系统理论探讨了现代太阳周（１８５０年１月－１９９２年５月）黑子相对数月平均变化过程的可预报性。用时间延迟方法重构吸引子，计算它的最大Ｌｙａｐｕｎｏｖ指数（λ１＝０．０２３±０．００４ ｂｉｔｓ／月），估算了用这些黑子数进行确定性预报的理论时限（ｔ＝３．６±０．６年）。结果表明，动力系统的可预报性与它的最大Ｌｙａｐｕｎｏｖ指数有直接关系，黑子数月平均变化过程的演化不是周期的，也不是拟     

太阳黑子相对数的分维研究

本文用非线性动力系统理论控制了现代太阳周（１８５０年１月－１９９２年５月）黑子相对数月平均变化的动力行为和可预报性，计算了它的分维数。结果表明，太阳黑子数月均变化是一个复杂的低维浑沌系统，可用有限个参数描述，所需变量至少为３个，最多为７个，本文还讨论了黑子数月均值的可预报时间尺度，平均可预报时间尺度为１５０个月，本文建议利用最小二乘直线拟合的最小方差来判定最佳无标度区，所得分维数较客观，并简要讨论     

太阳黑子数R_Y和R_L的稳定性分析

黑子数用国际系统ＲＩ作标准，与云南天文台ＲＹ、国内联合ＲＬ比较，分别求出总平均值：ｑ（Ｙ）＝０．９３００４±０．００４７２，ｑ（Ｌ）＝０．９１４０９±０．００４４４。这是后者删除“偶然误差”次数多于前者的结果。对国内联合数据的处理，应以一个观测点为准，以此归算作补充的部分数据，才有可能使数据系列保持相对的稳定     

太阳活动周的3个参量：AS,BT和BW

通过对１２－２２周（（１８７８－１９９５年）太阳大黑子群分布南北半球不对称的整体特征的研究,探讨了太阳活动周的长期演化趋势．约定Ｎ与Ｓ分别表示北南半球大黑子群数之和,ＢＮ与ＢＳ为北南半球大黑子群的纬度和．由这４个物理量定义了太阳活动周的３个参量：（１）太阳活动不对称指数ＡＳ＝（Ｎ－Ｓ）／（Ｎ＋Ｓ）;（２）平均纬度ＢＴ＝（ＢＮ＋ＢＳ）／（Ｎ＋Ｓ）,ＢＳ取负值;（３）太阳活动带的宽度ＢＷ＝ＢＮ／Ｎ－ＢＳ／Ｓ．对上述１１个活动周,得到了有关８０年周期的性质及奇偶数周大黑子群数变化的有意义的统计结果．     

第23太阳活动周不会是强活动周

利用最新的太阳黑子观测资料和线性相关统计模式,对第２３太阳活动周的极大月平滑黑子相对数和黑子数的极大年均值进行预测．预报因子分别是每个太阳周上升相第２６个月的月平滑黑子相对数和第三年的黑子数年均值．预测结果表明,第２３周太阳黑子数的极大值不会高,极大月平滑黑子相对数为１１５．４±１４．９,极大年均值为１１８．９±１１．６．平滑黑子数极大不会出现在１９９９年,很可能出现在２０００年．     

太阳运动与海河气候、水文相关研究新进展

在黄河、淮河和海河流域，旱、洪、涝灾害频繁，水土流失及水资源短缺日趋严重．它包括北京、天津等重要城市及１０多个省区，在我国社会发展中举足轻重．对其气候、水文的超长期（１０———１００年）预报，为该地区经济全面可持续发展规划所必需，在某种程度上关联于民族振兴．目前预报提前量一般是一年，更长的提前量，大都寄希望于它与太阳活动的相关．迄今，太阳周的预报成功率较低；超太阳周预报，尚无实际可用．董士仑［１］基于黑子数资料系统演变的研究，发现太阳运动角动量变率Ｊ（ｔ）与黑子数年均值的线性相关系数高达０．８１…     

冕洞的地磁效应

分析了２２太阳活动周（１９８６．１－１９９５．６；ＣＲ１７７１－ＣＲ１８９８）冕洞对地磁扰动的长期效应和短期效应。作为长期效应，赤道冕洞数和面积指数随太阳活动周伦与同期的地磁ＡＰ指数的长期变化基本一致，二者在ａ＝０．０１扒度水平上密度相关，表明赤道冕洞不仅对低年的磁扰有贡献，而且对峰年期间地磁拓动的贡献不可忽视的。对冕洞的短期地磁效应的研究表明，不论哪种类型的冕洞，在它们过中经后的１－４天，地磁４     

活动星系核红移分布中的准周期峰

本文作者在活动星系核红移分布（０＜ｚ≤０．２）中发现了准周期性的峰。这些峰分布于ｚ≈０．０３０，０．０６０，０．０９０，０．１２０处（其中ｚ＝０．０６０处的峰是１９６８年Ｂｕｒｂｉｄｇｅ发现的并于１９９０年证实）。红移数据的功率谱表明。这些峰值的准周期为△ｚ＝０．０２７±０．００２。两个相邻的峰所表征的空间距离为８１±６ｈ~（－１）Ｍｐｃ。这可能是宇宙大尺度结构中各个单元的特征尺度（Ｈ_０＝１００ｈ~（－１）Ｍｐｃ~（－１）ｍｓ~（－１）。     

卫星积分多普勒定位观测的初归算结果

本对１９８４年４月－１９８５年４月在南京紫金山山上大人卫测点，用积分多普勒观测的二维单点定位资料进行了分析。并根据卫星来自ＳＥ、ＳＷ、ＮＥ、ＮＷ四个象限获取的资料，分别进行了归算和处理，结果精度如下：σφ（ＳＥ）＝３．７ｍ，σφ（ＳＷ）＝４．２ｍ σφ（ＮＥ）５．１ｍ，σφ（ＮＷ）＝６．５ｍ σλ（ＳＥ）＝４．９ｍ，σλ（ＳＷ）＝５．６ｍ σλ（ＮＥ）３．３ｍ，σλ（ＮＷ）＝４．０ｍ上述表达式中     

冕洞的地磁效应

分析了２２太阳活动周（１９８６．１—１９９５．６；ＣＲ１７７１—ＣＲ１８９８）冕洞对地磁扰动的长期效应和短期效应。作为长期效应，赤道冕洞数和面积指数随太阳活动周的演化与同期的地磁Ａｐ指数的长期变化基本一致，二者在α＝０．０１的信度水平上密切相关，表明赤道冕洞不仅对低年的磁扰有贡献，而且对峰年期间地磁扰动的贡献也是不可忽视的。对冕洞的短期地磁效应的研究表明，不论哪种类型的冕洞，在它们过中经后的１—４天，地磁Ａｐ指数都有不同程度的增长；大冕洞比小冕洞引起的地磁效应较强烈；跨越赤道的冕洞比未跨越赤道的同级冕洞引起的地磁效应较强烈     

A survey of orbits of co-orbitals of Mars

Many asteroids with a semimajor axis close to that of Mars have been discovered in the last several years. Potentially some of these could be in 1:1 resonance with Mars, much as are the classic Trojan asteroids with Jupiter, and its lesser-known horseshoe companions with Earth. In the 1990s, two Trojan companions of Mars, 5261 Eureka and 1998 VF₃₁, were discovered, librating about the L₅ Lagrange point, 60° behind Mars in its orbit. Although several other potential Mars Trojans have been identified, our orbital calculations show only one other known asteroid, 1999 UJ₇, to be a Trojan, associated with the L₄ Lagrange point, 60° ahead of Mars in its orbit. We further find that asteroid 36017 (1999 ND₄₃) is a horseshoe librator, alternating with periods of Trojan motion. This asteroid makes repeated close approaches to Earth and has a chaotic orbit whose behavior can be confidently predicted for less than 3000 years. We identify two objects, 2001 HW₁₅ and 2000 TG₂, within the resonant region capable of undergoing what we designate “circulation transition”, in which objects can pass between circulation outside the orbit of Mars and circulation inside it, or vice versa. The eccentricity of the orbit of Mars appears to play an important role in circulation transition and in horseshoe motion. Based on the orbits and on spectroscopic data, the Trojan asteroids of Mars may be primordial bodies, while some co-orbital bodies may be in a temporary state of motion.     

Equation of state and anisotropy of pressure of magnetars

Magnetars are the neutron stars with the highest magnetic fields up to 10¹⁵–10¹⁶ G. It has been proposed that they are also responsible for a variety of extra-galactic phenomena, ranging from giant flares in nearby galaxies to fast radio bursts. Utilizing a relativistic mean field model and a variable magnetic field configuration, we investigate the effects of strong magnetic fields on the equation of state and anisotropy of pressure of magnetars. It is found that the mass and radius of low-mass magnetars are weakly enhanced under the action of the strong magnetic field, and the anisotropy of pressure can be ignored. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.     

Estimation of the Time Scale of Merging of the Components of Contact Binaries of the W UMa Type

Time scales of the transition from contact binary systems of the W UMa type to single stars of the blue straggler type are estimated. A model of one-way mass transfer from the primary component to the companion inside a common envelope (Eggen et al.) and a model of a contact binary lying on the zero-age main sequence with a companion that is losing mass (F. van't Veer) are used to calculate these scales. The merging times of components were calculated for 304 contact systems of the W UMa type from the Catalog of Approximate Photometric and Absolute Elements of Eclipsing Variable Stars on a scale of loss of mass and orbital angular momentum due to magnetic braking, under the assumption of synchronization of the axial rotation and orbital revolution. On the basis of the resulting statistics, the characteristic merging scales are 0.4-0.6 and 0.5-0.7 Gyr, respectively, for the above two models. The results of a comparison with the work of other authors are discussed.     

Modeling of lightcurves of binary asteroids

We present a numerical method for inverting long-period components of lightcurves of asynchronous binary asteroids. Data of five near-Earth binary asteroids, (175706) 1996 FG₃, (65803) Didymos, (66391) 1999 KW₄, (185851) 2000 DP₁₀₇ and (66063) 1998 RO₁, for two of them from more than one apparition, were inverted. Their mutual orbits' poles and Keplerian elements, size ratios, and ellipsoidal shape axial ratios were estimated via this inversion. The pole solutions and size ratios for 1999 KW₄ and 2000 DP₁₀₇ are in a good agreement with independent estimates from radar measurements. We show that uncertainties of estimates of bulk densities of binary systems can be large, especially when observed on short arcs.     

Investigation of Times of Minima of Selected Early-Type Eclipsing Binaries

New precise times of minimum light for several early-type eclipsing binaries were obtained at three observatories. The changes of period of the following measured binaries are discussed: V1182 Aql, LY Aur, SZ Cam, FZ CMa, QZ Car, LZ Cen, V606 Cen, AH Cep and TU~Mus.     

Flattening of galaxies of different morphological types in subclusters of Coma

This paper deals with the observed variation in the flattening of galaxies with the density of galaxies in the subclusters of Coma surrounding NGC 4889, NGC 4874, and NGC 4839 based on data from the Abastumani Combined Catalog of Galaxies. The mean values of the observed ratios of the diameters of the galaxies, as well as histograms of their distributions, indicate that in the central, dense regions of the subclusters within a volume of 0.5h ₇₅ ⁻¹ Mpc³, E and S0 type galaxies are close to spheroidal. A significant reduction in the mean values of the diameters of the galaxies in the subclusters is noted, regardless of their morphology relative to the galaxies in the halo of the Coma cluster. In the subclusters, spiral galaxies are found with a hydrogen deficit that is more than 5 times the hydrogen deficit in spirals within the halo of the cluster. According to their 3-D coordinates, most of the galaxies with a hydrogen deficit are located closer to the south-east edge of the subcluster surrounding NGC 4874 near an extended gas filament in the x-ray region. This may indicate that the subcluster is moving toward a central condensation of faint galaxies in the Coma cluster and a possible merger with it. __________ Translated from Astrofizika, Vol. 50, No. 3, pp. 355–368 (August 2007).     

Influence of Neutron Star Parameters on Evolutions of Different Types of Pulsar

Influences of the mass, moment of inertia, rotation, absence of stability in the atmosphere and some other parameters of neutron stars on the evolution of pulsars are examined. It is shown that the locations and evolutions of soft gamma repeaters, anomalous X-ray pulsars and other types of pulsar on the period versus period derivative diagram can be explained adopting values of B < 10¹⁴ G for these objects if they have smaller mass (e.g. about 0.5 Solar mass) compared to the conventionally adopted values of mass. This approach gives the possibility to explain many properties of different types of pulsar.     

淮河洪水的可公度性分析

分析了上两个世纪发生在淮河的洪水事件的可公度性，根据其可公度值及其黄金分割点指出1991年与2003年淮河洪水的不可避免，最后讨论了可公度性的局限及淮河洪水可公度值的可能机制。     

基于STK的寿命末期GEO卫星轨道演化分析

地球同步轨道上的GEO卫星接近寿命末期时,星上的有效载荷和电子元器件等仍能正常应用,此时如果只做东西方向的位置保持,可以大幅度延长卫星的在轨工作寿命。简要介绍了引起GEO卫星轨道变化的主要摄动力,利用STK软件分析寿命末期GEO卫星的运动规律,并给出这类GEO卫星轨道演化的仿真分析流程,用以指导寿命末期GEO卫星的开发应用工作。     

On the application of optimization methods to the determination of members of families of periodic solutions

The techniques used for the numerical computation of families of periodic orbits of dynamical systems rely on predictor-corrector algorithms. These algorithms usually depend on the solution of systems of approximate equations constructed from the periodicity conditions of these orbits. In this contribution we transform the root finding procedure to an optimization one which is applied on an objective function based on the exact periodicity conditions. Thus, the determination of periodic solutions and families of such orbits can be accomplished through unconstrained optimization. In this paper we apply and compare some well-known minimization methods for the solution of this problem. The obtained results are promising. This revised version was published online in July 2006 with corrections to the Cover Date.