轴对称稳恒磁场的一种解法     

孙新民  丁世荣 《地球科学与环境学报》1997,(2)

本文依据稳恒磁场中的高斯定理和安培环路定理，用迭代法推导出对称轴上的磁感应强度与空间任意一点磁感应强度的关系式，从而可得出轴对称稳恒磁场的无电流分布空间的解式。  相似文献   

Self-regulated black hole accretion, the M–σ relation and the growth of bulges in galaxies     

Mitchell C. Begelman †  Biman B. Nath ‡ 《Monthly notices of the Royal Astronomical Society》2005,361(4):1387-1392

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粤东海涂土壤及其利用     

张希然 《云南地理环境研究》1990,2(1):72-81

粤东海岸东起闽粤交界的大埕湾,西迄深圳市的大鹏湾,岸线曲折,港湾较多,河溪人海泥沙在潮间带及紧邻5m 等深线以内形成大片海涂,土壤类型多样,以泥质和沙泥质土壤为主;除河口湾的土壤含盐量低外,其余较高;土壤有机质含量中等,钾素较丰富,磷素较低。因地处亚热带南缘,光、热和水资源条件较好,且多数海湾有深入内地的小海湾和潮沟,甚适合发展海水养殖与晒盐,韩江口的义丰河和海门龟头海大闸外等滩地尚有围垦价值。多处海湾潮滩沙土适合作海滨浴场,也有小片滩地红树林适合旅游观赏。  相似文献   

Consolidation of double‐layered ground with vertical drains     

Xiao‐Wu Tang  Katsutada Onitsuka 《国际地质力学数值与分析法杂志》2001,25(14):1449-1465

Vertical drains are usually installed in subsoil consisting of several layers. Due to the complex nature of the problem, over the past decades, the consolidation properties of multi‐layered ground with vertical drains have been analysed mainly by numerical methods. An analytical solution for consolidation of double‐layered ground with vertical drains under quasi‐equal strain condition is presented in this paper. The main steps for the computation procedure are listed. The convergence of the series solution is discussed. The comparisons between the results obtained by the present analytical method and the existing numerical solutions are described by figures. The orthogonal relation for the system of double‐layered ground with vertical drains is proven. Finally, some consolidation properties of double‐layered ground with vertical drains are analysed. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

观驾山—黑岛一带信息量法找金研究     

简文星  吕贻峰  秦松贤  刘吉平 《国土资源》1996,(2)

本文以成矿地质模型为依据，对观驾山—黑山岛一带的化探、物探、遥感及地质等信息变量进行了详细的分析，选取了１０个信息变量２４个标志状态；在此基础上，运用信息量法对研究区内４５８个单元的信息量值进行计算，并由此确定了研究范围内的成矿远景区。事实表明，研究区信息量成矿预测是非常有效的  相似文献   

关于改进的Encke方法中参考轨道的选择和校正     

刘林  胡松杰 《天文学报》1996,37(3):285-293

对于改进的Ｅｎｃｋｅ方法，选择适当的参考轨道是一个关键．然而，对于人造地球卫星长弧轨道计算，目前所给出的几种参考轨道均需要逐段校正，这将给定轨问题带来附加的复杂性．本文将仔细探讨如何选择参考轨道和减少校正次数．  相似文献   

Revised masses of dust and gas of SCUBA Local Universe Survey far-infrared bright galaxies based on a recent CO survey     

Ernest Seaquist  Lihong Yao  Loretta Dunne  Heather Cameron 《Monthly notices of the Royal Astronomical Society》2004,349(4):1428-1434

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A continuum‐discrete hydromechanical analysis of granular deposit liquefaction     

M. Zeghal  U. El Shamy 《国际地质力学数值与分析法杂志》2004,28(14):1361-1383

A coupled continuum‐discrete hydromechanical model was employed to analyse the liquefaction of a saturated loose deposit of cohesionless particles when subjected to a dynamic base excitation. The pore fluid flow was idealized using averaged Navier–Stokes equations and the discrete element method was employed to model the solid phase particles. A well established semi‐empirical relationship was utilized to quantify the fluid–particle interactions. The conducted simulations revealed a number of salient micro‐mechanical mechanisms and response patterns associated with the deposit liquefaction. Space and time variation of porosity was a major factor which affected the coupled response of the solid and fluid phases. Pore fluid flow was within Darcy's regime. The predicted response exhibited macroscopic patterns consistent with experimental results and case histories of the liquefaction of granular soil deposits. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Optimal deflection of NEOs en route of collision with the Earth   总被引：1，自引：0，他引：1  

Ralph Kahle  Gerhard Hahn 《Icarus》2006,182(2):482-488

Recently, a method for the n-body analysis of the velocity change required to deflect a hazardous near-Earth object (NEO) was presented by Carusi et al. [Carusi, A., Valsecchi, G.B., D'Abramo, G., Boattini A., 2002. Icarus 159, 417-422]. We extent this method in order to optimize the velocity change vector instead of its along-track magnitude. From an application of both methods to a fictitious NEO we find Carusi's parallel approach to be reasonable for phases of unperturbed two-body motion. But, for orbit phases inhering third-body perturbations, i.e., for planetary close approaches or prior to a collision, the results obtained from the new method show the radial component of deflection impulse to play a major role. We show that a fivefold greater efficiency can be achieved by a deflection impulse being non-parallel to orbital velocity. The new method is applied to two possible 99942 Apophis impact trajectories in order to provide constraints for future Apophis deflection mission analysis.  相似文献   

Erratum: Dark matter in elliptical galaxies – I. Is the total mass density profile of the NFW form or even steeper?     

《Monthly notices of the Royal Astronomical Society》2006,370(3):1581-1581

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