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281.
根据模糊综合评判理论,结合钻井资料的分析,建立了一套对钻井参数进行评价和优选的方法。整个过程简单易行,可对实际钻井中钻进参数的合理组配和优化提供有价值的信息。 相似文献
282.
平面裂隙参数计算及其对浆液流动的影响分析 总被引:2,自引:0,他引:2
利用从层流到紊流的多阶段稳定压水试验的压力-流量曲线反算裂隙张开度、粗糙度及地下水影响半径等裂隙参数。建立了平面裂隙中浆液流动的力学模型,并分析了对浆液流动的影响因素。 相似文献
283.
本文对利用强震近场加速度记录确定时,空、强三个完整的震源参数。文中给出一种利用计算机自动识别地震记录的P波初动到时和S波震相到的算法。根据新近发表的Wood-Anderson地震仪器的最新参数,修牍正唐山地区量规函数。利用唐 山数字震观测台阵得到的近场加速度数据,计算了10次地震的震源位置和震级,并对定位误差进行了综合分析,将强震台网测定的震源参数与地震台 相似文献
284.
本文利用变参数回归分析建立了多口井的泥质岩储层裂缝密度模型。该模型的平均相对误差为13.5%,较常系数回归分析、BP网络模型进行裂缝预测的精度高(平均相对误差分别为38.7%、17.9%)。通过实际资料处理认为该油田在纵向上随时代变老,深度加深,裂缝密度降低。即从N22、N12到N1,平均裂缝密度从0.78条/m、0.5条/m降低到0.3条/m。在平面上,沿构造轴部裂缝最发育,平均裂缝密度N22、N12、N1层分别为0.58条/m、0.6条/m、0.3条/m。 相似文献
285.
高速公路路基性态反分析及沉降预报 总被引:10,自引:1,他引:9
本文用三元件粘弹性流变模型模拟路基土体的流变特性, 根据施工期实测资料, 采用粘弹性有限元和非线性二乘法阻尼优化方法, 反演路基土体的地质力学参数, 然后计算路面铺筑后的工后沉降, 编制了土体粘弹性有限元正反分析程序, 并对沪宁高速公路某路段进行了反分析计算, 得到了满意的结果。 相似文献
286.
N. Jackson S. Nair I. W. A. Browne P. N. Wilkinson T. W. B. Muxlow A. G. de Bruyn L. Koopmans M. Bremer I. Snellen G. K. Miley R. T. Schilizzi S. Myers C. D. Fassnacht D. S. Womble A. C. S. Readhead R. D. Blandford & T. J. Pearson 《Monthly notices of the Royal Astronomical Society》1998,296(3):483-490
A new four-image gravitational lens system, B0712+472, has been discovered during the Cosmic Lens All-Sky Survey. This system consists of four flat-spectrum radio images that are also seen on a Hubble Space Telescope ( HST ) image, together with the lensing galaxy. We present MERLIN, VLA and VLBA maps and WHT spectra of the system as well as the HST images. The light distribution of the lensing galaxy is highly elongated and so too is the mass distribution deduced from modelling. We suggest a redshift of ∼1.33 for the lensed object; the lens redshift will require further investigation. The discovery of this new system further increases the ratio of four-image to two-image lens systems currently known, exacerbating problems of required ellipticity of matter distributions in lensing galaxies. 相似文献
287.
Local stellar kinematics from Hipparcos data 总被引:1,自引:0,他引:1
Walter Dehnen & James J. Binney 《Monthly notices of the Royal Astronomical Society》1998,298(2):387-394
288.
Michael Feast Frederic Pont & Patricia Whitelock 《Monthly notices of the Royal Astronomical Society》1998,298(2):L43-L44
A value for the zero-point (ρ) of the Cepheid period–luminosity relation, < M V >= 2.81 log P + ρ, is deduced by comparing the value of the Oort constant, A , derived from radial velocities with that derived from Hipparcos proper motions. We find in this way that ρ =−1.47 ± 0.13, in excellent agreement with the value derived from Hipparcos trigonometrical parallaxes, ρ = −1.43 ± 0.10, by Feast &38; Catchpole in a recent paper. 相似文献
289.
290.
The balance conditions of relative angular momentum and time-mean kinetic energy and their annual variations are studied for the Northern Hemisphere tropical belt. The belt is divided into two roughly equal size parts, the monsoon and the extramonsoon regions. The data used consist of all available daily rawinsonde reports from the world areological network for the two 5-year periods 1958–63 and 1968–73.In winter, the trade winds in the monsoon and extramonsoon regions are both sources of westerly relative angular momentum for the middle latitude circulation. However, it is found that the angular momentum gained in the extramonsoon region of the Tropics is mostly destroyed by a net southward flow of mass in that region, and becomes regenerated in the monsoon region by a net northward flow of mass there. This excess of angular momentum together with the angular momentum picked up locally in the monsoon region is almost all exported across its northern boundary. It is further found that in winter the Tropics are also an important source of mean kinetic energy for middle latitudes. Again almost all export of kinetic energy was found to take place across the northern boundary of the monsoon sector. Most of this energy must be generated through the pressure gradient term inside the monsoon region itself, the transformation from transient eddy kinetic energy being very small. The proper evaluation of the pressure gradient appears to be the main stumbling block in the present study, preventing us from estimating the generation and thereby, as a residual, the frictional dissipation in the two regions.In summer, the extramonsoon region remains a source of angular momentum, but the monsoon region with its surface westerlies acts as a sink, leading to a sharp reduction (and even a midsummer reversal) of the export into middle latitudes. Also the export of mean kinetic energy almost vanishes in summer, except for a small southward transfer across the equator. The calculations for two 5-year periods give very similar estimates and thereby show the reliability of the results.Parts of this paper were presented at the International Symposium on Monsoons, March 7–12, 1977 in New Delhi, India. 相似文献