Aspherical accretion of cosmic strings

A simulation of accretion of a string loop has been done. It shows that aspherical accretion is essential for large-scale loops. All configurations found in the distribution of galaxies, such as filaments, pancakes, bubbles, and voids, can be formed by the accretion of cosmic strings.     

任意空间剖面图打印的实用程序

本文介绍了一个根据测站的经度(或纬度)打印任意空间剖面图的实用程序,通过自定义坐标,可打印在国家气象局制的6300号底图上。本程序采用BASIC语言,已在 Apple-Ⅱ上实现,对其中的部分语句修改后,也可以用于IBM-PC等其它微机上,用本程序制图,速度快,准确性高,可作为日常性的天气分析预报工具。     

THE FIRST METEOROLOGICAL SATELLITE OF CHINA——FENGYUN-Ⅰ

At 0430 Beijing summer Time 7 September 1988,the first Chinese meteorological satellite.named Fengyun-1(FY-1 meaning observing the wind and clouds in the atmosphere) was launched into the near-polar sun-synchronous orbit successfully at the Taiyuan Satellite Launching Center,Shanxi Province by Long March-4 launching vehicle which was developed by the Ministry of Aeronautics and Astronautics.FY-1 satellite is a hexahedron of 1.4m×1.4m×1.2m (Fig.1).The attitude of satellite is three-axis. stabilized.The satellite at an altitude of 900 km operates around the earth 14 passes per day with a period of 102.86 min.The main instruments aboard the satellite are two Advanced Very High Resolution Radsometer (AVHRR) and Space Environmental Monitor.Table 1 gives the major specifications of AVHRR.     

The crystal structure of (Fe<Subscript>4</Subscript>Cr<Subscript>4</Subscript>Ni)<Subscript>9</Subscript>C<Subscript>4</Subscript>

(Fe4Cr4Ni)9C4 is a metal carbide mineral formed by combination of Fe, Cr and Ni with C. It occurs in a chromite deposit in the Luobusha ophiolite, Tibet. Based on the determination of its crystal structure, the empirical formula is (Fe4.12Cr3.84Ni0.96)8.92C3.70 and the simplified formula is (Fe4Cr4Ni)4C9. The mineral is hexagonal with a = 1.38392(2) nm, c = 0.44690(9) nm, pace group P63 m c, Z=6 and the calculated specific gravity Dx = 7.089 g/cm3. Fe, Cr and Ni occupy different crystallographic sites and their coordination numbers are approximately 12, forming an alternate stacking sequence of flat and puckered layers along the c axis. Some metallic atoms have a defect structure. The interatomic distances of Fe, Cr and Ni are 0.2525-0.2666 nm, and the distances between Fe, Cr, Ni and C are 0.1893-0.2169 nm. The coordination number of carbon is 6. It occurs in interstices of the metallic atoms Fe, Cr and Ni to form trigonalprismatically coordinated polyhedra. These coordination polyhedra are linked with each other via shared corners or shared edges into a new type of metal carbide structure.     

我国能源资源的现状及其合理利用问题

本文从讨论能源的概念和分类入手,阐述了我国能源资源的储量及其地理分布,并针对能源开发利用中的特点和问题,提出了合理利用我国能源资源的若干建议。     

Wind tunnel simulation experiment and investigation on the electrification of sandstorms

~~Wind tunnel simulation experiment and investigation on the electrification of sandstorms~~     

基于DEM的彩色地貌晕渲的制作

本文围绕计算机环境下数字地貌晕渲实现的理论与技术展开了探讨,论述了数字地貌晕渲的相关理论,介绍了数字地貌彩色晕渲色彩设计的基本方法,对数字地貌晕渲的技术过程进行了深入研究。     

地图符号化中的几个关键问题研究

从应用的角度,对多地图符号库的组织和高效访问机制进行了研究.首次引入显示控制样式的概念,以解决不同比例尺下地图的屏幕显示效果问题,同时基于显示控制样式管理,研究了屏幕显示效果与打印效果统一的问题.文中采用地图符号库索引加缓存符号描述信息的机制,提高了访问多地图符号库中描述信息的速度;采用显示控制样式控制要素层在不同比例尺下是否显示、显示的详细程度及采用哪种显示样式;采用双显示控制样式库解决屏幕显示效果和打印效果的统一问题.实践证明,该研究成果可以很好地解决多地图符号库管理和高效访问问题,改善地图的显示效果和控制地图的显示速度;另外还可以保证地图屏幕显示和打印输出效果的统一.     

水泥混凝土路面施工质量管理

加强混凝土路面施工全面质量管理,一定要严格按国家有关规范和评定标准施工和验收。加强水泥混凝土路面施工管理和质量控制,对加快道路建设步伐,提高工程质量,节省投资,更好地服务于社会经济发展具有十分重要的意义。     

警用综合地理信息系统数据模式设计与实现

详细介绍在构建警用综合地理信息系统过程中所需要的空间基础数据模式、空间专题数据模式;通过地址码数据库的构建完成空间数据和警用专业数据这两种异构数据的集成过程。并以该系统一个子系统为例简要说明数据的构成模式、集成模式。