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91.
The prograde amphibole that coexists with chlorite, epidote, muscovite, albite, quartz and hematite in Sanbagawa schists was examined to investigate the relationship between the prograde P-T paths of individual rocks and the metamorphic field gradient in the Sanbagawa metamorphic belt, central Shikoku. The amphibole changes from actinolite, through ferri-winchite and crossite, to barroisite and hornblende with increasing grade along the metamorphic field gradient. However, the sequence of prograde amphibole compositions in each sample varies in different mineral zones. The general scheme can be summarized as: magnesioriebeckite-riebeckite crossite in the upper chlorite zone of lower-grade rocks; crossite or glaucophane barroisite in the garnet zone of medium-grade rocks; and actinolite or winchite barroisite hornblende in the albite-biotite zone of higher-grade rocks. Changes of amphibole composition indicate that the prograde P-T path recorded in the higher-grade rocks was situated on the higher-temperature side of that of the lower-grade rocks and on the lower-pressure side of the metamorphic field gradient. The systematic change of P-T paths implies an increasing d P /d T during continuous subduction. These features can be interpreted as documenting prograde metamorphism within a young subduction zone that has a non-steady-state geotherm. 相似文献
92.
D. Perner U. Platt M. Trainer G. Hübler J. Drummond W. Junkermann J. Rudolph B. Schubert A. Volz D. H. Ehhalt K. J. Rumpel G. Helas 《Journal of Atmospheric Chemistry》1987,5(2):185-216
Using long path UV absorption spectroscopy we have measured OH concentrations close to the earth's surface. The OH values observed at two locations in Germany during 1980 through 1983 range from 0.7×106 to 3.2×106 cm-3. Simultaneously we measured the concentrations of O3, H2O, NO, NO2, CH4, CO, and the light non methane hydrocarbons. We also determined the photolysis rates of O3 and NO2. This allows calculations of OH using a zero dimensional time depdendent model. The modelled OH concentrations significantly exceed the measured values for low NO
x
concentrations. It is argued that additional, so far unidentified. HO
x
loss reactions must be responsible for that discrepancy. 相似文献
93.
一个CDP道集经动校正后,多次波仍存在剩余时差δt,它随炮检距呈抛物线变化。由δt的变化即可求出多次波剩余波数△K的分布规律。据此,可设计一个理想的叠加剩余波数响应,用于动校正后的CDP道集的加权叠加。在t~x平面选择δt,即可改变叠加剩余波数响应,从而改变各道的加权系数,实现最佳压制多次波的效果。 相似文献
94.
吉南古元古代集安群泥质变质岩P—T—t轨迹及其地质意义 总被引:3,自引:0,他引:3
吉南古元古代分布区大地构造划分为辽吉裂谷系和浑江裂陷槽,集安群是辽吉裂谷系早期产物。泥质变质岩呈北东向分布于裂谷带内,经历了形成期后的中高级变质作用。本文在岩石建造、地质构造等研究基础上,通过变质作用研究,利用变质石榴石环带分析方法,建立了集安泥质变质岩P-T-t轨迹。该轨迹表明集安群形成以来经历了两次拉张变质作用。在变质作用动态过程中,泥质原岩发生变质变形,P-T-t轨迹反映了该区古元古代地质演 相似文献
95.
元素迁移的分维结构、级序路径及共轭地球化学异常存在的理论依据 总被引:5,自引:0,他引:5
微量元素在矿源岩(层)中迁移遵循严格的级序路径,并且存在两种迁移倾向。迁移的结果图象是一分维结构。两种共轭地球化学异常出现的有利环境是温度高度反差地区和大断裂系及其附近。 相似文献
96.
Further Studies Of Atmospheric Turbulence In Layers Near The Surface: Scaling The Tke Budget Above The Roughness Sublayer 总被引:2,自引:0,他引:2
The second of two experimental studies of the TKE budget conducted on sites of different roughness is described, and results are compared. The first took place within a shallow layer above a small field of mostly bare, cultivated soil; the second was carried out above a roughness sublayer of significant depth on an extensive plain of tall dry grass. Budget terms observed in the second study were scaled with a modified u which compensated for effects of an unusually large stress gradient and ensured that the m functions would be collinear. By showing that the modification becomes negligible in smaller gradients, it is demonstrated that in normal conditions, budgets observed above significant roughness sublayers should be normalized by scaling in terms of the unreduced Reynolds stress at the sublayer's upper surface. This procedure is shown to be consistent with the expectation that TKE budgets in layers near the surface all scale in fundamentally the same way.Other findings include: (1) the fact that most m functions previously reported are not quite collinear is attributed to a type of overspeeding known to affect three-cup anemometers; (2) revised m functions, collinear and largely free of the effects of overspeeding, are determined from a well-established characteristic of the linear m relation for the stable case; (3) data that define collinear m functions can also be represented with single hyperbolic curves; (4) dissipation is found to be 10 to 15% too small to balance total TKE production in unstable and neutral conditions and to decrease with increasing z/L in thestable regime; and (5) new relations for based on the observed behaviour of the dissipation deficit provide an improved closure for the set of equations that express the budget terms as functions of m and z/L. 相似文献
97.
钢筋混凝土建筑抗倒塌设计 总被引:14,自引:2,他引:14
建筑抗倒塌问题近年来在欧美国家得到广泛关注,并颁布了相关的设计规范和标准。我国还没有制定有关建筑抗倒塌方面的规范和标准。本文提出一种基于建筑危险性的钢筋混凝土建筑抗倒塌设计方法。该方法将钢筋混凝土建筑分为四类,通过设置拉杆连接系统和Alternate Path设计提高建筑抗倒塌能力。 相似文献
98.
99.
WIN32下电子地图制图与应用系统设计 总被引:1,自引:0,他引:1
探讨了电子地图制作和分析应用的相关技术,并认为电子地图已从“只读”系统向“分析”系统发展,电子地图的应用分析功能将成为今后研究的重点。 相似文献
100.
本文针对目前我省上行报文发送情况的现状,说明了建立上行气象报文监控和转发系统的关键技术,包括:使用三层模式、三层模式中各个层次的功能、接收和转发报文的过程、监控系统的运行状态,如何统一处理气象报文等。 相似文献