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51.
高分辨率遥感影像的精纠正 总被引:10,自引:1,他引:10
论述了对高分辨率遥感影像进行精纠正获得正射影像的关键技术。若干实际不同分辨率的高分辨率遥感影像被用于相应的实验,实例证明了本文算法的正确性。 相似文献
52.
Tetsuya Komabayashi Soichi Omori Shigenori Maruyama 《Physics of the Earth and Planetary Interiors》2005,153(4):191-209
Fluid-undersaturated experiments were conducted to determine the phase relations in the simplified peridotite system MgO-SiO2-H2O (MSH) at 11.0-14.5 GPa and 800-1400 °C. Stability relations of dense hydrous magnesium silicates (DHMSs) under fluid-undersaturated conditions were experimentally examined. From the fluid-absent experimental results, we retrieved thermodynamic data for clinohumite, phase A, phase E, and hydrous wadsleyite, consistent with the published data set for dry mantle minerals. With this new data set, we have calculated phase equilibria in the MSH system including dehydration reactions. The dehydration reactions calculated with lower water activities of 0.68-0.60 match the fluid-present experiments of this study above 11.0 GPa and 1000 °C, indicating that considerable amounts of silicate component were dissolved into the fluid phase. The calculated phase equilibria illustrate the stability of the post-antigorite phase A-bearing assemblages. In the cold subducting slab peridotite, phase A + enstatite assemblage survives into the transition zone, whereas phase A + forsterite + enstatite assemblage forms hydrous wadsleyite at a much shallower depth of about 360-km. The slab is subducted with no dehydration reactions occurring when entering the transition zone. The phase equilibria also show the high temperature stability of phase E. Phase E is stable up to 1200 °C at 13.5 GPa, a plausible condition in the mantle of relatively low temperature, i.e., beneath subduction zones. Phase E is a possible water reservoir in the mantle as well as wadsleyite and ringwoodite. 相似文献
53.
54.
We have measured P- and S-wave velocities on two amphibolite and two gneiss samples from the Kola superdeep borehole as a function of pressure (up to 600 MPa) and temperature (up to 600 °C). The velocity measurements include compressional (Vp) and shear wave velocities (Vs1, Vs2) propagating in three orthogonal directions which were in general not parallel to inherent rock symmetry axes or planes. The measurements are accompanied by 3D-velocities calculations based on lattice preferred orientation (LPO) obtained by TOF (Time Of Flight) neutron diffraction analysis which allows the investigation of bulk volumes up to several cubic centimetres due to the high penetration depth of neutrons. The LPO-based numerical velocity calculations give important information on the different contribution of the various rock-forming minerals to bulk elastic anisotropy and on the relations of seismic anisotropy, shear wave splitting, and shear wave polarization to the structural reference frame (foliation and lineation). Comparison with measured velocities obtained for the three propagation directions that were not in accordance with the structural frame of the rocks (foliation and lineation) demonstrate that for shear waves propagating through anisotropic rocks the vibration directions are as important as the propagation directions. The study demonstrates that proper measurement of shear wave splitting by means of two orthogonal polarized sending and receiving shear wave transducers is only possible when their propagation and polarization directions are parallel and normal to foliation and lineation, respectively. 相似文献
55.
分析了事故的后果和经济损失,详细论述了由于生产活动的中止和人的死亡或劳动能力的丧失而导致的生产活动中劳动力资源损失的计算方法,并应用面向对象的数据库系统Cache′和Delphi开发工具编写了事故经济损失计算程序,以货币形式给出了每个损失点的损失大小并输出可能损失的报告书,为事故管理、安全决策和风险评估提供了科学的依据. 相似文献
56.
Gianluca Iezzi Mario Tribaudino Giancarlo Della Ventura Fabrizio Nestola Fabio Bellatreccia 《Physics and Chemistry of Minerals》2005,32(7):515-523
The synthetic amphibole Na0.95(Li0.95Mg1.05)Mg5Si8O22(OH)2 was studied in situ at high-T, using IR OH-stretching spectroscopy and synchrotron X-ray powder diffraction. At room-T the sample has P21
/m symmetry, as shown by the FTIR spectrum. It shows in the OH region two well-defined and intense absorptions at 3,748 and
3,712 cm−1, respectively, and two minor bands at 3,667 and 3,687 cm−1. The main bands are assigned to the two independent O–H groups in the primitive structure. The two minor bands evidencing
the presence of small amount of vacant A-site (A□0.05). With increasing T, these bands shift continuously and merge into a unique absorption at high temperature. A change as a function of increasing
T is revealed by the evolution of the refined unit-cell parameters, whose trend shows a transition to C2/m at about 320–330°C. The spontaneous scalar strain, fitted with a tricritical 2–6 Landau potential, gives a T
c of 325(10)°C (β parameter = 0.27). Comparison with the second-order P21
/m ⇔ C2/m phase transition at 255°C for synthetic amphibole ANa0.8B(Na0.8Mg1.2)CMg5Si8O22(OH)2 indicates that the substitution of Na with Li at the B-sites strongly affects the thermodynamic character and the T
c of the phase transition. The comparison of LNMSH amphiboles with cummingtonitic ones shows that the high-T thermodynamic behaviour is affected by A-site occupancy. 相似文献
57.
王建文 《测绘与空间地理信息》2016,(5):197-199
GB/T 50353-2013建筑工程建筑面积计算规范于2014年7月1日开始实施,该规范是在总结原有规范基础上进行修订的,目前,新规范实施已经一年多了,依据新规范审批的建设工程陆续进入验收阶段,因此,在建筑面积测量中如何正确用好新规范显得尤为重要。本文就新规范的技术要点进行分析,以便于技术人员和管理人员正确使用新规范。 相似文献
58.
针对桥梁建设中各构筑物放样坐标的计算及校核存在不严谨之处,本文提出一种计算放样坐标的新方法可以作为放样坐标的第一计算方法或检核方法。对其中所涉及的坐标系的转换和方位角的计算方法进行详细说明,并编制程序使计算智能化,可以应用在实际工程中,具有一定的实际应用价值。 相似文献
59.
现有多源同比例尺道路网匹配方法中,大多只利用道路自身特征进行匹配,而较少顾及道路周边要素对匹配过程的影响和约束,从而影响了道路网匹配效果的进一步提高,特别是对系统误差改正后仍存在一定位置或旋转偏差的道路数据进行匹配时,这种影响尤为明显。本文借鉴人类对陌生环境的空间认知特点,提出了一种顾及邻域居民地群组相似性的道路网匹配方法。该方法通过构建城市骨架线网确定与道路相邻的居民地群组,进而计算居民地群组空间关系和几何特征相似度来获得对应道路的匹配结果。其特点在于:对存在位置或旋转偏差的道路数据匹配,以其邻域空间内居民地群组的整体相似性指标来带动道路自身匹配,实际上是增加了周边居民地群组对道路匹配过程的约束,更具鲁棒性。试验及对比分析表明,本方法能够较好地解决系统误差改正后仍存在较大位置和旋转偏差的道路数据间的匹配问题,提高匹配的正确率。 相似文献
60.
受气候变化与人类活动的影响,水文序列一致性遭到破坏,传统的频率计算方法受到挑战。针对石羊河流域8条河流年径流量序列,在基于水文变异诊断系统进行变异分析的基础上,采用条件概率分布法和混合分布法进行了变化环境下的年径流频率计算。结果表明,石羊河流域年径流量序列以向下跳跃变异为主,变异年份多集中在1960年附近;变异序列的两种分布均通过K-S检验,最优分布的拟合效率系数均大于0.97;对比由考虑变异的理论分布与不考虑变异的一致性P-III型分布确定的设计年径流量,当设计频率高于90%时,大靖河与西营河的设计年径流量值相差较大。因此,石羊河流域新建水利工程的规划设计,应适当考虑水文资料的变异特性,选择合理的频率分析方法确定设计年径流量。 相似文献