电测深ρ＿s差值法的应用效果     

杨昌桂 《湖南地质》1994,(1)

用电测深研究地电断面、寻找隐伏多金属矿体时，以往采用ρ＿ｓ（或η＿ｓ）等值线断面图进行地质推断解释，因受浅源信号的干扰，效果差。本文提出了采用ρ＿ｓ（或η＿ｓ）差值法，能排除浅源干扰信号，反映出地电断面的相对变化，突出了深部微弱信息，取得了较好的地质解释效果。  相似文献   

Computerized streamflow measurement using slug injection     

Geoff Kite 《水文研究》1993,7(2):227-233

Using current meters to estimate flows in fast mountain streams is difficult and inaccurate. The salt dilution method offers an easier and more accurate alternative. The method has been used for many years but is time consuming and messy because of the need to mix chemical solutions and measure chemical concentrations in the field. A computer program has been developed which uses a laptop computer to calculate the mixing length and the mass of salt needed. The program controls the conductivity measurements and calculates the streamflow directly in the field. The development of this program is described and examples are presented of the application of the method in the Rocky Mountains of Alberta and British Columbia.  相似文献   

瞬变电磁法探测公路隧道工程中的不良地质构造     

薛国强  宋建平  武军杰  刘社华 《地球科学与环境学报》2003,25(4):73-75

为了给公路设计部门提供选线依据,运用瞬变电磁法在山西境内的某两条高速公路隧道工程设计线路段上进行探测,以查明下覆不良地质构造的发育情况.通过对瞬变电磁法的探测能力进行理论上的讨论,对不同地电断面情况下的异常体电磁响应的定性分析,得出用瞬变电磁法探测不良地质体的可行性结论.经过资料处理,查出不良地质构造赋存的位置,解释结果与钻探资料完全吻合.  相似文献   

A new stereo‐analytical method for determination of removal blocks in discontinuous rock masses     

Zixin Zhang  P. H. S. W. Kulatilake 《国际地质力学数值与分析法杂志》2003,27(10):791-811

The paper provides a new stereo‐analytical method, which is a combination of the stereographic method and analytical methods, to separate finite removable blocks from the infinite and tapered blocks in discontinuous rock masses. The methodology has applicability to both convex and concave blocks. Application of the methodology is illustrated through examples. Addition of this method to the existing block theory procedures available in the literature improves the capability of block theory in solving practical problems in rock engineering. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

强势语下的无奈——辜鸿铭古籍英译的归化     

张小波 《广东海洋大学学报》2004,24(5):70-74

通过对辜鸿铭所翻译的《中庸》、《论语》进行分析和研究 ,反映出社会背景对中国古典文化经典翻译的不同策略的影响。从而证明辜鸿铭译文的别出心裁出于强势语下的无奈。从翻译理论上揭示归化翻译的历史意义以及译品存在的价值。  相似文献   

Statistics of the individual-pulse polarization based on propagation effects in the pulsar magnetosphere     

S. A. Petrova 《Monthly notices of the Royal Astronomical Society》2006,368(4):1764-1772

Pulsar radio emission is modelled as a sum of two completely polarized non-orthogonal modes with the randomly varying Stokes parameters and intensity ratio. The modes are the result of polarization evolution of the original natural waves in the hot, magnetized, weakly inhomogeneous plasma of the pulsar magnetosphere. In the course of the wavemode coupling, the linearly polarized natural waves acquire purely orthogonal elliptical polarizations. Further on, as the waves pass through the cyclotron resonance, they become non-orthogonal. The pulse-to-pulse fluctuations of the final polarization characteristics and the intensity ratio of the modes are attributed to the temporal fluctuations in the plasma flow.
The model suggested allows one to reproduce the basic features of the one-dimensional distributions of the individual-pulse polarization characteristics. Besides that, the propagation origin of the pulsar polarization implies a certain correlation between the mode ellipticity and position angle. On a qualitative level, for different sets of parameters, the expected correlations appear compatible with the observed ones. Further theoretical studies are necessary to establish the quantitative correspondence of the model to the observational results and to develop a technique of diagnostics of the pulsar plasma on this basis.  相似文献   

The Asiago Extrasolar Planet Transit Search     

R. U. Claudi  M. Cancian  M. Barbieri  R. Gratton  S. Desidera  M. Montalto  G. P. Piotto  S. Scuderi 《Astrophysics and Space Science》2006,304(1-4):251-251

RATS is an Italian project devoted to Hot Jupiter search with the transit method. A planet transiting in front of a host star can be mimed by several, and well defined, astrophysical phenomena (Brown, 2003). In order to recognize these false alarms we can utilize a preventive strategy to limit false alarm rates and a spectroscopic follow up to refuse no transit candidates. As preventive strategy it is important to develop an accurate target field selection, with well defined requisites, in order to maximize the solar type star numbers and to minimize the risk of possible astrophysical false alarms.  相似文献   

Strong magnetic field in W75N OH maser flare     

V. I. Slysh  V. Migenes 《Monthly notices of the Royal Astronomical Society》2006,369(3):1497-1501

A flare of OH maser emission was discovered in W75N in 2000. Its location was determined with the Very Long Baseline Array (VLBA) to be within 110 au from one of the ultracompact H  ii regions, Very Large Array 2 (VLA2). The flare consisted of several maser spots. Four of the spots were found to form Zeeman pairs, all of them with a magnetic field strength of about 40 mG. This is the highest ever magnetic field strength found in OH masers, an order of magnitude higher than in typical OH masers. Three possible sources for the enhanced magnetic field are discussed: (i) the magnetic field of the exciting star dragged out by the stellar wind; (ii) the general interstellar field in the gas compressed by the magnetohydrodynamic shock; and (iii) the magnetic field of planets which orbit the exciting star and produce maser emission in gaseous envelopes.  相似文献   

On the influence of magnetic fields on level populations     

Z. Q. Qu  C. L. Xu  X. Y. Zhang  X. L. Yan  C. L. Jin 《Monthly notices of the Royal Astronomical Society》2006,370(4):1790-1796

The influence of magnetic fields on the energy level populations of atoms is firstly studied by analysing the Stokes profiles of Fe  i 6302.5 forming in the solar magnetized atmosphere, with the aid of a departure factor defined to evaluate the deviation from the normal Boltzmann distribution without a magnetic field. This factor is directly related to the ratio of line-source function to the continuum one. The relationship between the departure and the magnetic field reveals an effect that the magnetic field induces an exponential increase in the level population of the lower level of Fe  i 6302.5 (Landé factor   g = 2.5  ) with the field strength. This indicates that the magnetic field can cause the redistribution of populations of those levels whose Landé factors are non-zero. Therefore, this effect should be included in the calculation of the statistical equilibrium. Secondly, an experiment utilizing the Hg5461 line in the laboratory on the Earth is carried out to reveal that the exponential relation is independent of variations in temperature, and the excitation is completely magneto-induced. Finally, the exponential relation is explained by taking account of the magnetic energy in the Boltzmann distribution.  相似文献   

The parsec-scale radio jet of BL Lac     

D. C. Gabuzda †  T. V. Cawthorne 《Monthly notices of the Royal Astronomical Society》2003,338(2):312-322

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