共查询到20条相似文献，搜索用时 46 毫秒
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通过对由亥姆赫兹线圈和测微平行光管构成的水准仪磁致误差检定装置的测量方法及其不确定度来源的分析,讨论了水准仪磁致误差检定的测量不确定度的评估方法,阐述了检定结果不确定度主要由测量重复性、测微平行光管的刻划误差和读数误差、磁场以及磁致误差特性曲线拟合引入。对这些分量分别进行分析与公式推导,最终评定出检定装置的扩展不确定度。 相似文献
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利用物理摆原理导出了自动安平水准仪磁致误差的理论函数模型,建立了地磁场中的观测方程。通过实测资料,分析了地磁场对Ｎｉ００２水准仪的影响,并对观测误差和Ｆ值的测定精度进行了讨论。 相似文献
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利用６个ＧＰＳ固定观测点３天的观测资料，采用伯尔尼３．５版软件用多种方法计算了长距离ＧＰＳ基线边及ＧＰＳ卫星轨道参数。结果表明，对８００～３０００ｋｍ的ＧＰＳ基线，利用精密星历计算，边长及其经纬度分量重复测量精度可达１０－８～１０－９；同精密星历相比，２天轨道弧段的定轨精度为１～４ｍ（坐标中误差）。显然，采用ＩＧＳ（国际地球动力学ＧＰＳ服务处）计算中心的精密星历可以满足地球动力学及地震预报研究对ＧＰＳ的精度要求，而利用国内的观测点资料作ＧＰＳ卫星定轨，可以满足一般测量的精度要求 相似文献
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重力仪的周期误差是精密重力测量的一个误差源。本文阐述由于齿轮组合所产生的周期误差,给出全部可能存在的周期数。以G584仪器为例,发现除已被普遍采用的1、7.33、73.33、220周期数外,尚存在22周期数。用大量程静电反馈装置进行测量,验证22周期数的周期误差幅值为4.33×10~(-6)m/S~2。同时讨论了为标定该项误差增强现有基线的必要性。 相似文献
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李延兴 《大地测量与地球动力学》1998,(1)
在精密ＧＰＳ测量中,大气折射改正误差是主要误差源之一。基于大气折射理论,把底层大气分为７层,并考虑不同高度的重力改正,建立了新的大气层模型,推导出了新的更精确的折射改正公式。实例计算结果表明,新的大气层模型更加符合实际。 相似文献
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任道胜 《大地测量与地球动力学》2000,20(2):72-77
基于试验和实践,讨论了数字水准仪的特性和误差来源及其对观测结果的影响。在此基础上阐述了该仪器应用于区域精密水准测量中应予关注的各种问题和提高精度的措施。指出：应制定有关该仪器的测量规范。 相似文献
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该航磁异常位于黄土覆盖区,通过分析区域地质资料,认为该航磁异常对应地下岩性为五台群的石咀亚群金岗库组地层,金岗库组地层是五台地区主要的含磁铁石英岩建造,结合该航磁异常形态规则,强度较高,推断为隐伏磁铁石英岩矿致异常,通过地面磁法扫面结合典型剖面测量,推断了磁性体的产状、埋深等特征,用钻探进行验证,取得了较好的找矿效果。 相似文献
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一、测量学的研究应用领域工程测量学的研究领域既有相对的固定性,又是不断发展变化的。工程测量学主要包括以工程建筑为对象的工程测量和以设备与机器安装为对象的工业测量两大部分。在学科上可划分为普通工程测量和精密工程测量。 相似文献
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本文以精密三角高程测量理论为基础,研究精密三角高程测量技术在青海高海拔地区的应用,通过测试验证了精密三角高程测量技术在高海拔地区的应用能取得较好的效果。 相似文献
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李永朝 《地球科学与环境学报》1999,21(3):60
对西康铁路大瓢沟隧道工程施工控制网的布设方案和观测技术进行了讨论,较准确地估算隧道的贯通误差,得出该隧道的平面施工控制网的测量成果,并详细探讨了精密工程控制网的等级划分、网形、点位、边长和角度。 相似文献
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Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area. 相似文献
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Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter. 相似文献
14.
《极地研究(英文版)》2014,(3)
正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied 相似文献
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《山地科学学报》2014,(4):I0004-I0009
<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet. 相似文献
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《山地科学学报》2014,(4)
<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by 相似文献
18.
References： 《极地研究(英文版)》2007,18(1):73-83
Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated. 相似文献
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The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature. 相似文献