概论机场能见度的准确预报     

张晓晖 《成都信息工程学院学报》2002,17(3):166-169

通过对影响能见度的因素的分析，提出了一种能见度预报方法－综合分析法，极大地提高了能见度的预报准确率。  相似文献   

伪随机码调制的CW半导体激光雷达试制报告     

肖弟权  何建新  邱万智 《成都信息工程学院学报》1993,(4)

本文报告一种用半导体激光器作光源,用子脉冲宽度100ns,长度为511的周期伪随机码对半导体激光器的输出作幅度调制;APD作光电检测器,高速数字信号处理器TMS320C25作信号处理的激光雷达组成方案和试作样机的实验结果。  相似文献   

Researches in China on the Effects of Tides on the Earth Rotation     

Naiyuan Xiao  Yifei Xia 《Celestial Mechanics and Dynamical Astronomy》2003,87(1-2):3-12

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   

基于CTI技术的守时系统故障报警实现   总被引：2，自引：0，他引：2  

蔡成林  董绍武 《时间频率学报》2003,26(2):103-110

介绍了计算机电话集成(CTI-Computer Telephony Integration)技术在守时系统故障自动报警中的应用。简要介绍了构成报警系统的两个关键产品，电话语音卡和TTS(Text-To-Speech)，详细讨论了ActiveX控件(Phonic．OCX)编程接口的一系列事件和方法以及由此而开发的故障报警模块。该模块不仅用于守时主系统的故障报警，也将用于电源系统、钟房环境监控系统的故障报警。  相似文献   

射电源0420—014,1334—127和2345—167中的视超光速运动     

沈志强  万同山  洪晓瑜 《中国天文和天体物理学报》1997,(1)

本文叙述南天区 5GHzVLBI普查中新发现的视超光速射电源 ,0 4 2 0— 0 1 4,1 334—1 2 7和 2 345— 1 67,这些结果尚待进一步的观测加以证实  相似文献   

FUZZY COMPREHENSIVE EVALUATION OF CONTAINER TRANSPORTATION MODES ALONG THE CHANGJIANG RIVER MAIN LINE AND ITS DELTA AREA   总被引：1，自引：0，他引：1  

ZHANGShi-yu XIAOHan-liang 《中国地理科学(英文版)》2003,13(3):259-261

The Changjiang River (Yangtze) is one of the fastest growth areas of container transportation in Chi-na. Rail, road and water transportation have competed against each other for container transportation in the Chang-jiang River main line and its delta area. It is of significance to assess these different transportation modes scientifi-cally in order to organize container transportation efficiently in this area and make decision for integral plan and construction of transportation system in this area. This paper outlines application of fuzzy comprehensive evaluation to appraise different modes of typical direction of containers. Twelve assessment indexes were decided. Membership functions were formulated. Evaluation results indicated that road transportation was optimal mode in the Changjiang River delta area, however water transportation was the primary way in the Changjiang River main line.  相似文献   

Ecohydrological change mechanism of a rainfed revegetation ecosystem at southeastern edge of Tengger desert,Northwest China     

Xiao  Honglang  Cheng  Guodong  Li  Xinrong  Song  Yaoxuan  Wang  Xinping 《中国科学:地球科学(英文版)》2004,47(1):71-77

Study is made on a 45 km-long artificial ecosystem without irrigation in Tengger desert on the basis of long-term ecological monitoring and ecohydrological fundamentals. Changes in water allocation, utilization, cycle and balance patterns in more than 40-year evolution of the soil-plant system are analyzed. The formation of a drought horizon in shrub rhizosphere and its effect, ecohydrological function of the crust and its effect on the soil-plant system change are discussed. Driven by water self-regulation and water stress, the soil-plant system is going to develop towards the steppe desert to ensure more effective use and optimum collocation of water resource.

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Free radical scavenging abilities of polypeptide from Chlamys farreri   总被引：1，自引：0，他引：1  

韩志武  初晓  刘成娟  王跃军  孙谧  王春波 《中国海洋湖沼学报》2006,24(3):325-328

1 INTRODUCTION Active oxygen free radicals can damage cell structure, even kill the cells, causing aging and cer- tain serious diseases (Bors et al., 1989). Usually, the production and scavenging of active oxygen free radicals are in balance in healthy hu…  相似文献   

RETRACTION: Numerical simulation of a wind-sand flow under different conditions of atmospheric stability     

LÜ PING  ZHIBAO DONG 《Sedimentology》2008,55(3):721-721

A theoretical model for wind‐sand flow is developed by considering the coupling between wind flow and sand particle motion, the latter subject to the Magnus effect, under different atmospheric stability conditions. Using this model, the characteristics of the wind‐sand flow are discussed in detail. The results show that the atmospheric stability and the Magnus effect both have a strong influence on wind profiles and on the trajectories of sand particles. This approach produces results with characteristics that differ from those previously reported; the latter only applying to atmospheric conditions of neutral stability. The saltating sand reaches a greater height under non‐neutral stability than under neutral stability, while the maximum horizontal distance is greater under unstable conditions and is smaller under stable conditions than under conditions of neutral stability.  相似文献   

XEPOS型偏振能量色散X射线荧光光谱仪分析蒙古铁矿石   总被引：5，自引：4，他引：1  

耿刚强  宁国东  王巧玲  丁慧  朱明达  白福全  董海成  牛素琴  王再田 《岩矿测试》2008,27(6):423-426

以熔融玻璃片和粉末压片制样,采用XEPOS型偏振能量色散X射线荧光光谱仪,建立了铁矿石中总铁、氧化钙、氧化镁、二氧化硅、三氧化二铝、硫、磷、铜等组分的快速分析方法。着重讨论硫、磷两元素测定的可行性和Lucas-Tooth、Price数学校正模型的适应性和改善方法的途径。  相似文献