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451.
1985—1986年度和1986—1987年度在菲尔德斯半岛对地面温度进行了测量,共获得129个数据,并对带回的样品进行了岩石热导率测量,共获得210个数据。本文在分析和归纳这些数据的基础上对菲尔德斯半岛的地温特征和岩石热物理性质进行了初步探讨。  相似文献   
452.
As an alternative to finite element or finite difference modelling, analytical solutions are derived by the method of Laplace transformation and numerical results obtained for several models of the bottom hole temperature stabilization. Included in the models are the finite circulation time, the thermal property contrast between the borehole mud and the surrounding formation, and the presence of radial or lateral fluid flow in the formation, all of which are found to have significant effects on the dissipation of the thermal disturbance induced by drilling.
The mud circulation is considered to have the effect of either maintaining the borehole mud at a constant temperature or supplying a constant amount of heat per unit length per unit time to the borehole. For small circulation times, the former reduces to the 'zero circulation' model in which the mud circulation creates an instantaneous temperature anomaly at the hole bottom; for small borehole radii, the latter reduces to the line source model and the traditional 'Homer plot'.
For typical drilling operations in which the bottom hole temperatures are measured several hours to several tens of hours after the hole is shut in, the new models generally predict higher equilibrium formation temperatures than does the Horner plot. However, predictions from the various models converge if the BHTs are taken after the hole has been shut in for a period which is greater than about five times the circulation period.  相似文献   
453.
Results of numerical simulation of currents in the western North Tropical Pacific Ocean by using a barotropic primitive equation model with fine horizontal resolution agreed well with observations and showed that the Mindanao Cyclonic Eddy located north of the equator and east of Mindanao Island exists during most of the year with monthly (and large seasonal) variations in scope . strength and central location . In June , an anticyclonic eddy occurs northeast of Halmahera Island, strengthens to maximum in August , exists until October and then disappears . The observed large-scale circulation systems such as the North Equatorial Current . the Mindanao Current and the North Equatorial Countercurrent are all very well reproduced in the simulations.  相似文献   
454.
455.
This paper describes a 5 GHz VLBI survey in the southern hemisphere. The first observation of 23 extragalactic radio sources was conducted in November 1992. Twenty VLBI images were obtained, of which 15 sources show core-jet structure, one has a two-sided jet, and three sources are unresolved. No compact double source was found. Eleven of the 16 sources with core-jet (including a two-aided jet) show evidence of jet bending. In addition, four sources appear to be superluminal, of which three sources are new.  相似文献   
456.
The physical basis of the linkage between magnitude and timing of channel flow hydrographs and drainage network morphometry is reviewed. Small Hortonian and structurally Hortonian networks are analysed using numerical runoff simulation. For Hortonian networks the variability of the geometry of individual channels and subcatchments within each Strahler order has generally little effect upon the overall character of the hydrograph in channels of higher order. If the network is also structurally Hortonian, the analysis of the simultaneous formation, travel, and concentration of the hydrographs in all channels of the network can be simplified to a sequence of one representative hydrograph per channel order. This approach is used in this study. Three major runoff processes control the flow hydrograph characteristics: the overland flow process which determines the water supply to the drainage network; the channel flow process which translates the hydrograph in space and time; and the drainage network process which concentrates and magnifies the flow at the junctions of the drainage network. Functional relations for the hydrograph peak, timing, and flow velocity are presented. For a given uniform rainfall and infiltration rate, the peak of the channel flow hydrograph is shown to increase geometrically with channel order, and its magnitude is directly related to the bifurcation ratio. The travel time of the peak also increases geometrically with channel order, and it is directly related to the channel length ratio over velocity ratio. The flow velocity of the peak changes in a downstream direction as a function of the bifurcation and slope ratio. It was also found that for negligible channel storage the channel flow and drainage network processes do not contribute significantly to the observed nonlinear response of a watershed to precipitation.  相似文献   
457.
本文在活断层研究和地震宏观调查的基础上,从现代地壳运动特征及活动断层几何学,运动特征等方面研究了1932年麻城Ms6.0级地震的蕴育环境条件,为预测该区强震的地点和强度提供依据。  相似文献   
458.
1IntroductionWestern Linyi of Shandong Province is one of the most important gold ore mineralization concen-tration areas. Tongjing skarn type gold copper de-posit, Jinchang skarn type gold copper deposit and Duijinshan porphyry type gold deposit were found in 1960's (Edited committee, 1996). Following the discovery of Guilaizhuang gold ore deposit related to alkaline rocks in 1988, the western Linyi region becomes one of the extensively studied areas of gold deposits in China (Lin etal.,…  相似文献   
459.
本文主要介绍沙赫(Shan,P.M.)公式,对二维任意倾斜地层的层速度计算的应用效果。依据实际地层剖面Φ、V、Z参数的可能变化,设计18个较为复杂的地层模型进行了大量试算,并与Dix公式计算结果作了对比,表明对任意倾斜地层应采用沙赫公式提取层速度才是适宜的。  相似文献   
460.
本文通过对北京东郊高碑店地区污染农田的调查研究,探讨了重金属在农田生态系统中的积累和循环,计算出重金属在区域环境中的输入输出量,说明本区仍处于重金属积累状态,为防治农田环境污染,提出了停止施用污水处理厂的晾干污泥,减少灌溉污水中的重金属含量等保护性措施。  相似文献   
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