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81.
某基坑工程土钉支护工作性状试验研究 总被引:1,自引:0,他引:1
通过对广州天河荟雅苑基坑工程土钉支护进行试验和研究,分析了土钉支护体系的工作性状,并为同类工程的设计提供了一定的依据。 相似文献
82.
姬塬油田长4+5砂岩储层孔隙类型与成岩作用 总被引:10,自引:1,他引:9
通过常规物性、岩石及铸体薄片、重矿物、X射线衍射、扫描电镜等多项测试方法,对鄂尔多斯盆地姬塬油田长4 5含油砂体的岩石学特征、成岩作用、储集类型进行了分析和研究。长4 5储层孔隙主要以粒间孔和长石溶孔为主,粒间溶孔次之,孔隙组合一般以粒间孔和溶孔-粒间孔为主。本区破坏性成岩作用包括机械压实作用、石英及长石的次生加大、碳酸盐胶结作用等,其中压实作用是造成本区砂岩原生孔隙大量丧失的主要原因。建设性成岩作用为溶蚀作用、绿泥石粘土膜形成作用,但溶蚀作用产生的次生孔隙对储层物性的改善不足。 相似文献
83.
大气湍流扰动严重影响了空间目标的观测、成像和识别。在目标图像的重建过程中,对成像系统和大气条件先验知识的缺乏使PSF(Point Spread Function)的估计成为解决病态问题的重要内容。在NSWT(NonSubsampled Wavelet Transform)和Fried参数的理论基础上,根据不同尺度下小波变换模极大值和高斯点扩散函数方差的关系,结合Fried参数提出一种新的估计方法,即基于非抽取小波变换模极大值的PSF估计算法。实验结果证明,该估计算法是确实可行的,重建的PSF能够有效地改善因受大气湍流影响的图像解卷积的效果。 相似文献
84.
基于天池煤矿地质勘探资料,结合区域构造背景研究了矿井地质构造特征及形成机制。天池煤矿构造属简单构造,地层总体呈走向北东、倾向北西的单斜构造,矿井内褶皱发育程度较低,断层以正断层为主,其次为低角度逆掩断层。陷落柱分布较为杂乱,成群出现,常见于褶皱轴部。自三叠纪末期开始一直受到区域构造活动的控制作用,印支期受SN向的挤压,形成了一些近EW向的构造;燕山期经历两期NWW--SEE向挤压使井田内地层及煤层主体呈NE走向;喜山早期的NE—SW向挤压,导致NE向断层的性质发生转变;上新世开始表现为区域上的伸展作用。 相似文献
85.
形变,应变短临前兆标志体系 总被引:1,自引:0,他引:1
建立各手段的前兆异常标志,从而组合各类前兆标志体系是“八五”地震短临预报攻关研究项目的重要目标之一。本文以形变,应变手段的主要研究对象,初步建立了一个形变应变短临前兆标志体系,并总结出了各种异常的判别标志,为利用系统优化理论和专家系统理论进一步研究形变应前兆系统和地震之间的关系,从而为提高中短期地震预报的水平打下了一定的基础。 相似文献
86.
Among the three principal regional units of Croatia, i.e. the elongated and spacious Adriatic littoral (with numerous islands), the relatively small and narrow mountainous belt (the Croatian transit doorway) and the Pannonian/peri-Pannonian region, the latter is the largest and accounts for 54 percent of the surface area and 66 percent of the population of Croatia (1991 census). It is part of the Pannonian (or Carpathian) basin, or the central Danube basin, so that Croatia is simply by its position a Danube country. Its Danube character is also highlighted by the fact that the Pannonian/peri-Pannonian region of Croatia through the Sava and Drava Rivers is directly linked to the navigable Danube, which is the historical and ethnic eastern boundary of Croatia. Croatia is an old historical Danube nation and country, although it has nominally appeared as a state after the break-up of Yugoslavia, and its international recognition as an independent state (1992). 相似文献
87.
Croatia is a country of tourism, and this is primarily due to its position by the warm Adriatic Sea, its varying and picturesque landscapes, its diverse and generally favorable climate for tourism, its rich Mediterranean and Central European cultural heritage and its proximity to the leading European consumer countries.In the international tourism market, Croatia presents itself with the slogan A Small Country for a Great Vacation, because its 4.8 million inhabitants and surface area of 56,538 km2 place Croatia in the ranks of the world's smaller countries. Its significance is increased by an additional 33,200 km2 of territorial waters, of which a large part is considered internal waters because of its location within the limits of a series of islands.The tourism offering of Croatia is very diverse, but its basis is formed by three differing and mutually complimentary regions, through their natural characteristics and cultural heritage: coastal, montane and Pannonian and peri-Pannonian Croatia. The total tourism offering of Croatia includes 900,000 beds, of which over one-fifth are in hotels or similar places, two-fifths are in private rooms and one-third in camps.The tradition of tourism in Croatia is over one hundred years old, and according to the number of foreign tourists it is ranked as the fifth country for tourism in southern Europe. 相似文献
88.
Summary Direct measurements of the thermal plasma parameters in the topside ionosphere reveal variations of the plasmasphere boundary in the dusk sector. The ACTIVE satellite's near-polar orbits at altitudes of 500 – 1800 km around winter solstice 1989 were used to study the bulge region of the plasmasphere during intervals with different levels of geomagnetic agitation. The narrow, sharply defined trough in electron concentration corresponding to the plasmapause under quiet conditions situated at L = 6 – 7 moved to lower L-values with increasing geomagnetic activity. This narrow trough can be found in all main ion constituents. During periods of moderate geomagnetic activity, following the onset of a weak magnetic storm, a portion of the plasmaspheric bulge region was separated from the main plasmaspheric body. This can be seen in the outer ionosphere as an inner narrow trough at lower L-value. Troughs in light ions need no longer coincide with this in electron concentration. He+ is the most sensitive constituent reflecting the dusk sector plasmaspheric situation at this altitude.Dedicated to the Memory of Professor Karel P 相似文献
89.
L. Lazić 《Meteorology and Atmospheric Physics》1993,52(3-4):101-111
Summary The University of Belgrade/National Meteorological Centre, Washington (UB/NMC) limited area Eta Model predicted the development, structure, associated precipitation and tracks of the Australian Monsoon Experiment (AMEX) (10 January through 15 February 1987) tropical cyclonesConnie, Irma, Damien andJason. The initial positions and intensities of the tropical cyclone vortices from the global European Centre for Medium-Range Weather Forecasts (ECMWF) analyses, which are used as initial data, do not quite agree with the observations. These disagreements produce additional erros in predicting the tropical cyclone tracks.To improve the initial position of the vortex, the flow is split into the small and the large scale motions, and during the first two hours of the integration, the small-scale part is forced in small steps towards its observed position. The adjustment is performaed with the reduced model dynamics (adjustment processes only) and no physics.With the adjustment during the first two hours of the integration, the model successfully adjusts to the new position of the initial vortex. After the completion of the adjustment stage, the model runs normally, i.e., without any modification. The tracks of the 48-h forecasts with the adjusted initial vortices are parallel to the tracks obtained in the control forecasts without the adjustment. However, e.g., the mean absolute error of the positions during 48-h forecast of the tropical cycloneConnie was reduced from 174 km in the control case to 129 km in the case with adjustment of the position.The latent heat, the thermal energy, the kinetic energy and the total energy of the extracted small scale vortices are calculated every three hours of the integration time. These small-scale energies obtained in the 48-h control forecast are compared to those of the rund with the initial vortex adjustment to monitor the spin up of the model.With 7 Figures 相似文献
90.
Gojko Djurašević 《Astrophysics and Space Science》1993,206(2):207-218
The paper is devoted to the actual problematics in the determination of orbital and physical parameters of active CB on the basis of the interpretation of photometric observations. One solves the problem in two stages: by obtaining a synthetic light curve in the case when the parameters of the corresponding CB model (Djuraevi, 1992a) are given a priori (direct problem) and by determining the parameters of the given model for which the best fit between the synthetic light curve and the observations is achieved (inverse problem) (Djuraevi, 1992b). In this paper, the above procedure is applied to a particular case of an interpretation of CB light curves AU Ser and RV Corvi. 相似文献