描述地壳垂直运动过程的一种函数形式     

杨国华  巩曰沐  卢景忠  韩月萍 《大地测量与地球动力学》1995,(1)

本文在已有数据处理方法的基础上，利用近代数值逼近理论，给出了从时空域角度描述地壳垂直运动过程的一种具体的函数解析形式。最后给出了一个实际算例。  相似文献   

Re-Identification of the ＇Enigmatic＇ X-ray Source 1RXS J114003.0＋124112     

Jiang-Hua Wu Tigran Movsessian Yang Chen Xiang-Tao He Xu Zhou Jun Ma 《中国天文和天体物理学报》2006,6(4):430-434

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测定天琴RR变星金属丰度的方法     

吴潮  胡景耀  赵永恒 《天文学进展》2006,24(4):308-318

银晕中天琴RR变星金属丰度的测定对于研究银河系晕的形成和演化具有重要的意义．在当前的技术条件下,高分辨光谱的方法难以测量银晕中较暗的天琴RR变星的金属丰度．高分辨光谱测定金属丰度的方法对恒星大气模型的依赖性较高,而恒星脉动引起的复杂大气状况对于建立正确的大气模型本身就是挑战．△S光谱方法、Caby测光方法和光变曲线的参数方法则弥补了高分辨光谱方法的不足,将能测量更远距离上的天琴RR变星的金属丰度．着重介绍了这3种方法发展的历史、具体的观测流程以及需要注意的问题。通过比较这3种方法的优劣,为实际观测时方法的选用提供借鉴。  相似文献   

基于蚁群算法的城市可持续发展综合评价   总被引：1，自引：0，他引：1  

徐婷婷  于扬  彭娇婷 《成都信息工程学院学报》2006,21(5):694-697

在可持续发展体系分类的基础上，应用蚁群算法对可持续发展各分类指数公式和综合指数公式进行优化，建立可持续发展评价模型。将该模型应用于乌鲁木齐市可持续发展水平评价，评价结果与现状分析一敛。结果表明该模型简单适用、有良好的通用性。  相似文献   

Erratum: Towards cosmological concordance on galactic scales     

Frank C. van den Bosch  H. J. Mo  Xiaohu Yang 《Monthly notices of the Royal Astronomical Society》2004,348(2):736-736

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A multi‐level parallelized substructuring‐frontal solution for coupled thermo/hydro/mechanical problems in unsaturated soil     

H.R. Thomas  H.T. Yang  Y. He  P.J. Cleall 《国际地质力学数值与分析法杂志》2003,27(11):951-965

This paper proposes a multi‐level parallelized substructuring–frontal combined algorithm for the analysis of the problem of thermo/hydraulic/mechanical behaviour of unsaturated soil. Temperature, displacement, pore water pressure and pore air pressure are treated as the primary variables in a non‐linear analysis. Details are given firstly of the substructuring–frontal combined approach. The incorporation of the algorithm in a multi‐level parallel strategy is then discussed. The parallel processing can thus be carried out at different substructural levels. The method thus developed impacts, in a positive way, on both computer storage requirement and execution time. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

CPLD技术及其在现代时统中的应用     

杨蕾  胡永辉 《时间频率学报》2003,26(1):40-47

对CPLD(复杂可编程逻辑器件)技术的基本特征和发展趋势作了简要介绍,揭示了该技术在现代数字系统中的重要地位及作用.利用CPLD对时统设备IRIG-B码产生器进行集成,其实验结果表明,集成了的B码产生器不但简单、可靠,而且便于调试,克服了以往硬件电路复杂的缺点.  相似文献   

应用GPS观测青藏高原东北缘应力场变化   总被引：2，自引：0，他引：2  

张永志  胡斌  陈宏宾 《地球科学与环境学报》2003,25(4):80-84

采用各向同性弹性地球模型推导了地面位移场速率与地壳内任意点应力场变化的边界积分关系,同时利用青藏高原东北缘1999～2001年观测的GPS资料对观测区地壳深度为5 km和25 km的主应力和最大剪应力进行了计算分析.结果表明,青藏高原东北缘的主应力变化主要集中在祁连山断裂、海原断裂等,在1920～1954年间历史上发生过多次震级为7.0～8.5级强震的断裂附近,并具有主应力变化沿断层走向分布、最大剪应力沿断层走向交替变化等特征.  相似文献   

STUDY ON THE INTERACTION BETWEEN NDVI PROFILE AND THE GROWING STATUS OF CROPS   总被引：5，自引：1，他引：4  

JIANGDong WANGNai-bin YANGXIao-huan WANGJi-hua 《中国地理科学(英文版)》2003,13(1):62-65

Daily and ten-day Normalized Difference Vegetation Index(NDVI) of crops were retrieved from meteorological statellite NOAA AVHRR images ,The temporal variations of the NDVI were analyzed during the whole growing season,and thus the principle of the interaction between NDIV profile and the growing status of crops was discussed,As a case in point,the relationship between integral NDVI and winter wheat yield of Henan Province in 1999 had been analyzed.By putting integral NDVI values of 60 sample counties into the winter wheat yield-integral NDVI coordination,scattering map was plotted. It demonstrated that integral NDVI had a close relation with winter wheat yield.These relation could be described with linear,cubic polynomial ,and exponential regression,and the cubic polynomial regression was the best way,In general ,NDVI reflects growing status of green vegetation ,so crop monitoring and crop yield estimation could be realized by using remote sensing technique on the basis of time serial NDVI data together with agriculture calendars.  相似文献   

DISASTER ANALYSIS AND COUNTERMEASURES OF LAND SUBSIDENCE CAUSED BY COAL CUTTING IN CHINA     

YANGYong-liang SHITong-guang JLANGLU-guang LIYue 《中国地理科学(英文版)》2003,13(2):130-133

In recent years, many coal-producing countries have paid great attention to the land subsidence causedby coal cutting. In China, because of the dense population in coalfield areas, the land subsidence hazard is more seri-ous. After a brief analysis on the mechanism of land subsidence, this paper gives a comprehensive and systematical ac-count on all kinds of hazards caused by the land subsidence in China. The study shows that land subsidence has endan-gered land, buildings, traffic and communication lines, dykes and dams. It also causes damage to ecological and socialenvironment. In order to lessen the hazard of land subsidence, preventive measures should be taken to reduce the col-lapse amount, such as extraction with stowing, banded mining system, succession and coordination mining system, orhigh-pressure mudflow between rock strata. Measures of reinforcing or moving certain buildings should also be taken toreduce the destructive degree. In order to harness the subsidence land and bring them under control for fanning, mea-sures should be taken such as filling with spoil or fine breeze, excavating the deeper and covering the shallower land.  相似文献