重力插值方法研究     

向文 《大地测量与地球动力学》1997,(2)

为了根据离散观测数据构制连续空间重力变化图像，分析和讨论了３种数值插值方法，计算结果表明多面函数方法插值精度最高。由于逐步回归分析筛选核函数中心点的计算繁琐，文中提出根据分形理论和Ｓｈａｎｎｏｎ取样定理来确定核函数中心点。对滇西试验场进行模拟试算，插值精度可达到４～５（１０－８ｍｓ－２）。  相似文献   

流动VLBI站氢原子钟的研制与性能测试     

张为群  林传富  于双林  张一平  王关忠  张健  杨佩红 《天文学报》2001,42(1):94-100

氢脉泽是射电天文所必需的频率标准.文中对为流动vLBI站研制的新一代氢脉泽的物理结构特点进行了讨论，包括对腔泡结构、磁屏蔽、原子束光学系统等.同时性能测试表明在80秒到1天之间频率稳定度优于1×10  相似文献   

K-H Instability of Dust Plasma     

Shi Zhi-dong  Li Zhong-yuanUniversity of Science  Technology of China  Hefei    PRC Advanced Centre for Earth Science  Astronomy  Third World Academy of Science 《紫金山天文台台刊》1996,(2)

Areview about K-H instability related to comet tail is presented.The effect of dust graing on KHI is theoretically analysed and relations of critical shear to excit KHI with the properties of dust grains both for sheared ion flow and for sheared dust flow re put out.Their possible application in comet tail is suggested.  相似文献   

自动高精度测距系统     

张学庄  张驰 《大地测量与地球动力学》1996,(1)

介绍了自动高精度测距系统。该系统能以５×１０－７的测距精度测定多个观测点的形变，可作为跨断层动态连续观测的新仪器。  相似文献   

Influence of soft clays on the response spectra for structures in eastern Canada     

Ren  Tinawi  Marc Sarrazin  Andr  Filiatrault 《Soil Dynamics and Earthquake Engineering》1993,12(8):469-477

The 1990 edition of the National Building Code of Canada (Associate Committee of the National Building Code, National Research Council, Ottawa, 1990) makes a clear distinction between eastern and western Canada in terms of seismic acceleration and velocity zones. While it is well established that ground motions can be amplified significantly through loose clay deposits, no results are available that take into consideration the typical high frequency content of ground motions in eastern Canada. This paper develops ground amplification curves for clays having depths between 10 and 70 m excited by typical eastern Canadian ground motions scaled to two different values of peak horizontal accelerations. Simplified free-field spectral design curves, which could be used by structural designers, are proposed. The curves show that maximum spectral accelerations occur for structural periods between 0.2 and 0.5 s. In addition, soil depth does not appear to be an important parameter controlling the response of typical clay deposits in eastern Canada.  相似文献   

抗差估计的初值选择     

王振杰  欧吉坤  曲国庆 《大地测量与地球动力学》2001,21(3):32-35

对L1 范估计的平差值和LS估计的平差值作为抗差估计的初值进行了比较 ,指出在 ρ函数是严凸函数时 ,二者无明显的区别。因为LS估计简单且易于计算 ,因此建议用LS估计的平差值作为抗差估计的初值。  相似文献   

山东龙口市大磨曲家金矿地质特征及找矿方向探讨          下载免费PDF全文

刘晓煌  耿书杰  马树江  高池兴  赵新峰 《山东国土资源》2001,17(3):69-75

大磨曲家金矿位于玲珑金矿田东风矿床主脉的NE延伸部位.矿区内已发现矿脉25条.通过对玲珑金矿田的成矿条件分析和东风矿床的综合研究,认为本区有很好的找矿前景.  相似文献   

Urban tourism research methodology     

Tao Wei  Zhong Wen-hui  Hong Yan 《中国地理科学(英文版)》2005,15(2):173-178

  相似文献   

维生素E醋酸酯对鱼油脂肪酸含量变化的影响     

刘立鹤  郑石轩  周永奎  董爱华  吴建开  陈立侨 《广东海洋大学学报》2005,25(6):18-24

新鲜鱼油中添加05、0、2505、00 mg/kg 4种不同浓度的维生素E醋酸酯,在实验的第6、14、28、36和68天测定鱼油中的脂肪酸含量。结果表明:在500 mg/kg添加量内,维生素E醋酸酯对鱼油中脂肪酸含量没有显著性影响(P>0.05)。在实验期间,EPA(C20:5)、DHA(C22:6)、亚油酸(C18:2)含量明显下降,ARA(C20:4)、亚麻酸(C18:3)先升后降,棕榈酸(C16:1)逐步上升;C14含量逐渐增加,C17则先降后升,C16和C18在实验后期有较大提高。维生素E醋酸酯对鱼油中不饱和脂肪酸效用系数大小依次为:ARA>EPA>DHA>C18:3>0>C16:1>C18:2>C18:1,对ARA抗氧化效用最大,效用系数达到10.193%,C20:5为0.490%,C22:6为0.364%;维生素E醋酸酯对饱和脂肪酸效用系数大小依次为:C14>C17>0>C18>C16。  相似文献   

Early warning research on salt-alkalization desertification in western Songnen Plain     

BIAN Jian-min  LIN Nian-feng  TANG Jie College of Environment  Resources  Jilin  University  Changchun  Jilin  China 《东北亚地学研究》2005,(Z1)

Desertification is an environmental issue in the world. The salt-alkalization desertification land area formed by both primary and secondary salt-alkalization has extended in a large scale, which has become a significant eco-environmental problem. Based on the characteristics of eco-environment and the situation of desertification in western Songnen plain, this paper reports the analyzes of its formation in background and cause. An early warning system on the salt-alkalization desertification is established and the GIS technology is used to abstract the information of desertification evaluation index. Supported by the integrated technology of the GIS and ANN, the orientation and quantitative result of desertification are gained, which is helpful to the eco-environment protection and resource development in western Songnen Plain.  相似文献