The glacial extent and glacial advance/retreat asynchroncity in East Asia during Last Glaciation

New dates for last glacial cycle in Tibetan bordering mountains and in East Asia show the glacial extent during the early/middle (MIS3-4) stage is larger than that of the late stage (MIS2) in last glacial cycle. It is asynchronous with the Northern Hemisphere ice sheets maximum and changes in oceanic circulation that predominately control global climate. In research areas, three seasonal precipitation patterns control the accumulation and ablation of glaciers. The modes of the westerlies and the East Asian mountains/islands in and along the Pacific Ocean are favorable to glacier advance with mainly winter precipitation accumulation. There was a global temperature-decreasing phase in the middle stage (MIS3b, 54-44 ka BP), when the glacier extent was larger than that in Last Glaciation Maximum due to the low temperature combined with high moisture. It is revealed that the Quaternary glaciers not only evolved with localization, but also maybe with globalization. The latest studies show a fact that the developmental characteristics of glaciers in high mountains or islands along the western Pacific Ocean are not in accord with those inland areas. Therefore, it can be concluded that glacier development exhibits regional differences. The study validates the reasonableness of the asynchronous advance theory, and ascertains that both the synchronous and asynchronous advance/retreat of glaciers existed from 30 ka BP to 10 ka BP. It is not suitable to emphasize the synchronicity between global ice-volume and glacier change.     

Ajax技术在WebGIS中的应用

研究了Ajax技术在WebGIS中应用的可能性,讨论了在WebGIS中浏览器与服务器建立异步通信机制的方法,以及如何使用Ajax技术提升WebGIS的性能,同时指出了在WebGIS中应用Ajax技术时应该注意的问题。     

Asynchronism-synchronism of regional precipitation in South-to-North Water Transfer planned areas

This paper proposes a method on analyzing the asynchronism-synchronism of precipitation of different hydrological regions regarding the S-to-N water transfer areas of eastern China. The general process of the analysis includes three steps. Firstly, we created the rainfall series of the region concerned by calculating the regional average rainfall of the stations in the area with the help of the classical Thiessen Polygon method. Secondly, the standards of assessment indices for wetness or dryness are set according to Gamma distribution function with a certain probability P 37.5% or 62.5% given respectively. Finally, the frequency of nine combinations are counted as the quantitative feature of asynchronism and synchronism in three time scales, that is the yearly, seasonal and monthly scales. The asynchronism-synchronism of two region pairs has been estimated. The results show that the frequency of precipitation asynchronism in 1957-1998 is larger than the synchronism frequency for both the North China-middle and lower Yangtze River pair and for the North China-upper Hanjiang River pair. As for the synchronism phenomena, the frequency of Nd-Sd is rather low. As the combinations that are suitable for water transfers are Nd-Sw, Nn-Sw, Nd-Sn and Nn-Sn, the total frequency of these combinations for North China-middle and lower Yangtze River is 40% on an annual basis, but only 28% in spring when water shortages are most likely to occur. The total frequency of these combinations for North China-upper Hanjiang River is about 24% on an annual basis, but 35% in spring and winter. It should be noted that if future precipitation patterns are similar to that of the period 1957-1998, it is very important to change the natural character of asynchronism-synchronism by enhancing the capability of hydro-projects regulation and improving management of the water transfer project.     

基于Ajax的异步Web地图实现技术

Ajax是近几年出现的Web开发新技术。把Ajax技术应用到Web地图中,能够实现浏览器与地图服务器之间的异步交互,与采用传统同步方式的Web地图应用相比,具有用户界面反应灵敏,没有页面刷新带来的闪烁。本文研究了基于Ajax的异步Web地图实现技术,并在ASP.net平台上实现了基于Ajax的异步Web地图应用。     

次塑性模型及饱和砂土动力弹塑性响应分析

提出了一个新的次塑性模型并用试验作了初步验证,建议用异步交叉迭代显式差分有限元求解固液耦合动力弹塑性问题。利用次塑性模型以及动力固结有限元计算程序,对一简单饱和砂土地基的动力弹塑性响应进行了分析,取得了合理的结果。     

基于边界结点的GPS控制网边界异步环自动搜索算法

针对某些GPS数据处理软件搜索异步环不全的问题,本文提出了一种简单有效的基于边界结点的GPS控制网异步环自动搜索的算法。这种算法借鉴了Delaunay三角网的思想,通过建立Delaunay三角网,找出三角网上所有具有3条或3条以上边界边的边界结点,并依次搜索有边界结点的边界异步环和无边界结点的边界异步环,针对边界异步环,根据不同的观测时段数给出所有的基线组合,最后计算边界异步环的闭合差;并且根据此算法编写了软件,最后利用某县GPS平面控制网验证了该方法的可行性。     

PC104串行通信的应用

作者在文中详细阐述了PC104工控机串口的结构和工作机理，探讨了UART异步通信适配器的结构组成，并把该串口通信应用于MCA上，使数据采集仪器结构简单、轻便、体积缩小，便于携带和现场采集应用。     

具有异步控制器的离散马尔可夫跳变Lur'e系统的稳定性和l2增益性能分析

本文研究了一类具有异步控制器的离散马尔可夫Lur''e跳变系统的稳定性及l₂增益性能.通过引入隐马尔可夫模型（HHM）来描述所设计的控制器和原始系统之间出现的异步现象.利用线性矩阵不等式（LMI）方法分析了闭环系统的稳定性和l₂增益性能.然后提出了一个充分条件使得闭环系统随机稳定,并使得从扰动到系统输出的l₂增益达到最小.同时,通过求解给定条件来设计一个由线性状态反馈和扇形有界非线性输出反馈组成的异步控制器.最后,给出了一个数值仿真例子来验证所提方法的有效性.     

On the Asynchronous Rotation of Accretors in Interacting Binaries

We show that the gaining component in interacting binaries can rotate faster than its orbital revolution as a consequence of the accretion process. We derive an approximative analytical formula for the Roche lobe radius of asynchronously rotating accretors. We present the case of the semi-detached interacting binary TX UMa, for which we measured directly asynchronous rotation of its accretor. We suggest a method to detect indirectly a fast spinning of accretors in symbiotic binaries based on the the X-ray luminosity of the boundary layer. We demonstrate this possibility for the case of EG And.     

基于DSP的纸币号码识别系统

给出并实现了一种基于DSP的纸币号码识别系统。该系统通过视频解码器SAA7113将纸币号码图像转换成数字图像，并通过复杂可编程逻辑器件CPLD对SAA7113输出的数字图像进行开窗处理，以减小DSP的图像数据处理量和存储量。该系统的特点是在采用TI公司较廉价的54x系列DSP条件下，可以实现每秒25幅号码图像的视频采集速度，为实现具有纸币号码自动识别记录功能的点钞机奠定了基础。此外，系统还提供了与PC机通信的异步串行接口。