Transformation Process and Mechanism of Lithium Borates

正Amounts of lithium-containing salt lake brine resources are widely distributed in the four provinces named Qinghai,Tibet,Inner Mongolia and Xinjiang province,especially the salt lakes in Qinghai-Tibet Plateau are abundant of     

Regular and chaotic orbits in a self-consistent triaxial stellar system with slow figure rotation

We created a self-consistent triaxial stellar system through the cold disipationless collapse of 100,000 particles whose evolution was followed with a multipolar code. The resulting system rotates slowly even though its total angular momentum is zero, i.e., it offers an example of figure rotation. The potential of the system was subsequently approximated with interpolating formulae yielding a smooth potential stationary in the rotating frame. The Lyapunov exponents could then be computed for a randomly selected sample of 3,472 of the bodies that make up the system, allowing the recognition of regular and partially and fully chaotic orbits. The regular orbits were Fourier analyzed and classified using their locations on the frequency map. A comparison with a similar non-rotating model showed that the fraction of chaotic orbits is slightly but significantly enhanced in the rotating model; alternatively, there are no significant differences between the corresponding fractions neither of partially and fully chaotic orbits nor of long axis tubes, short axis tubes, boxes and boxlets among the regular orbits. This is a reasonable result because the rotation causes a breaking of the symmetry that may increase chaotic effects, but the rotation velocity is probably too small to produce any other significant differences. The increase in the fraction of chaotic orbits in the rotating system seems to be due mainly to the effect of the Coriolis force, rather than the centrifugal force, in good agreement with the results of other investigations.     

The Influence of Pan Evaporation Conditions on Na Cl crystallization

正1 Introduction Crystallization is one of important unit operations in the chemical production process,which requires not only the crystal product with high purity and yield,but also the available particle size of the crystal products to ensure product quality.Crystallization process is affected by     

Figures of equilibrium in close binary systems

The equilibrium configurations of close binary systems are analyzed. The autogravitational, centrifugal and tidal potentials are expanded in Clairaut's coordinates. From the set of the total potential angular terms an integral equations system is derived. The reduction of them to ordinary differential equations and the determination of the boundary conditions allow a formulation of the problem in terms of a single variable.     

Orbital structure of self-consistent triaxial stellar systems

We used a multipolar code to create, through the dissipationless collapses of systems of 1,000,000 particles, three self-consistent triaxial stellar systems with axial ratios corresponding to those of E4, E5 and E6 galaxies. The E5 and E6 models have small, but significant, rotational velocities although their total angular momenta are zero, that is, they exhibit figure rotation; the rotational velocity decreases with decreasing flattening of the models and for the E4 model it is essentially zero. Except for minor changes, probably caused by unavoidable relaxation effects, the systems are highly stable. The potential of each system was subsequently approximated with interpolating formulae yielding smooth potentials, stationary for the non-rotating model and stationary in the rotating frame for the rotating ones. The Lyapunov exponents could then be computed for randomly selected samples of the bodies that make up the different systems, allowing the recognition of regular and partially and fully chaotic orbits. Finally, the regular orbits were Fourier analyzed and classified using their locations on the frequency map. As it could be expected, the percentages of chaotic orbits increase with the flattening of the system. As one goes from E6 through E4, the fraction of partially chaotic orbits relative to that of fully chaotic ones increases, with the former surpassing the latter in model E4; the likely cause of this behavior is that triaxiality diminishes from E6 through E4, the latter system being almost axially symmetric. We especulate that some of the partially chaotic orbits may obey a global integral akin to the long axis component of angular momentum. Our results show that is perfectly possible to have highly stable triaxial models with large fractions of chaotic orbits, but such systems cannot have constant axial ratios from center to border: a slightly flattened reservoir of highly chaotic orbits seems to be mandatory for those systems.     

论新世纪衡阳城市形象的定位与塑造

衡阳市以位处南岳衡山之南而得名,自古以来自然、人文景观并胜,社会、经济、文化发达.近20多年来各方面反而停滞和落后.文中运用企业识别CI原理,从城市形象发展历史和现状入手,将其新世纪城市总体形象定位为"江南内陆腹地重要现代化区城中心 ,湘南最大交通枢纽,全国著名的山水旅游城市,环境优美、安全舒适的人居休闲胜地". 并指出城市形象塑造应体现古城衡阳的气韵和文脉,给人以古老文明、开拓进取、不断创新的总体视觉形象,以推动新世纪衡阳城市的总体发展.     

非连续分布面状地理现象的图形自动概括方法

本文首先阐述了图斑概括过程中应遵循的原则,即正确处理几何精确性与地理真实性、清晰性和详细性两对矛盾,继而提出了自动化制图综合的设计策略。然后探讨了非连续分布面状地理现象(即图斑)的自动取舍、化简、夸大和移位、以及合并等算法,介绍了上述算法的实现方法,并给出几种地物图形自动概括的应用技术流程。     

地球南北半球的非对称性

依据新的计算分析和空间观测数据,进一步论述了地球南北半球的非对称性. 全球热散失量的计算得出,南半球高出北半球33髎;南半球地幔热散失量是北半球的2倍. 比较南北半球S波速度分布,得出南半球的上地幔为低速、高温,北半球的上地幔为高速、低温. 计算地幔各层的质心位置发现,地球的质心偏于北半球. 计算地球经、纬圈长度的年变化率表明,南半球在扩张,北半球在收缩. 用空间大地测量数据的检测结果证实,南半球处于扩张状态,北半球处于压缩状态. 对地球的非对称性作了初步的动力学解释.     

The International Association of Geodesy 1862 to 1922: from a regional project to an international organization

Geodesy, by definition, requires international collaboration on a global scale. An organized cooperation started in 1862, and has become todays International Association of Geodesy (IAG). The roots of modern geodesy in the 18th century, with arc measurements in several parts of the world, and national geodetic surveys in France and Great Britain, are explained. The manifold local enterprises in central Europe, which happened in the first half of the 19th century, are described in some detail as they prepare the foundation for the following regional project. Simultaneously, Gauss, Bessel and others developed a more sophisticated definition of the Earths figure, which includes the effect of the gravity field. In 1861, the retired Prussian general J.J. Baeyer took up earlier ideas from Schumacher, Gauss, Struve and others, to propose a Central European Arc Measurement in order to study the figure of the Earth in that region. This led to a scientific organization, which soon extended from Central Europe to the whole continent and later to the globe, and changed its name in 1886 to Internationale Erdmessung (International Geodetic Association). The scientific programme also widened remarkably from more local studies based on geometric data to regional and global investigations, with gravity measurements as an important source of information. The Central Bureau of the Internationale Erdmessung was hosted at the Prussian Geodetic Institute in Potsdam, and with Baeyer as Director, developed as an efficient tool of the Association. The scientific research extended and deepened after 1886, when F.R. Helmert became Director of the Central Bureau. A stronger international participation then took place, while the influence of the German states reduced. Of great practical importance were questions of standardization and reference systems, but first attempts to interpret gravity field variations and to monitor geodynamic phenomena by geodetic methods indicated future tendencies. With the First World War and the expiry of the last international convention in 1916, the international cooperation within the frame of the Association practically came to an end, which ended the first epoch of the Association. Nevertheless, due to the strong commitment of two scientists from neutral countries, the International Latitude Service continued to observe polar motion and to deliver the data to the Berlin Central Bureau for evaluation. After the First World War, geodesy became one of the founding members of the International Union for Geodesy and Geophysics (IUGG), and formed one of its Sections (respectively Associations). It has been officially named the International Association of Geodesy (IAG) since 1932.