关键词： 地表移动   充分采动   影响函数   平面问题   竖直平面   采动系数   观测线   曲线拟合   点对应   方向特征  

摘要： <正> 目前实际采用的地表移动计算方法大都是以下面两个原理为基础的: 1、迭加原理:大面积开采对地表的影响,等于单元开采对地表的影响之和。 2、独立传播原理:开采引起的地表移动在走向和倾向两个竖直平面内的传播相互独立。前者为计算任意开采影响下的地表移动提供了方便,后者为使用平面问题解算空间问题提供了有效的途径。平面问题时,地表点的下沉W(x)利用迭加原理可表示如下

关键词： 地表移动   岩层   基本规律   岩移   岩层移动   影响函数   威布尔分布   水平移动曲线   块体理论   概率积分法   观测线   地质采矿条件   下沉曲线  

摘要： 本文是用碎块体理论研究由于地下开采引起的岩层和地表移动的基本规律的初步尝试。岩体被看作是一种各向异性的不连续的随机介质,是碎块体单元的集合。本文根据碎块体理论导出了表征岩层和地表移动的基本微分方程式,提出了影响函数的筛选法,确定了威布尔分布密度函数是最佳的影响函数形式。本文对用威布尔分布型影响函数进行地表移动预计的原理和方法做了系统的说明,说明了有关的电子计算机计算程序的使用方法,计算并分析了枣庄矿区十一个观测站的资料,证明了本文提出的理论和方法的合理性和可行性,并得出了一些有用的结论。本文还研究了影响预计可靠性的主要因素并提出了对预计结果加超载系数等相应的改进措施。

摘要： The mobility of electrons in n-type silicon has been calculated and compared with the available experimental data for temperatures between 5 and 80 K. Ionized impurity scattering is treated using the partial-wave phase-shift formalism. It is found that since the Born approximation is invalid at low temperatures, use of Brooks-Herring theory introduces serious error in that regime. For relatively pure samples excellent agreement between theory and experiment is observed, while the agreement is not as good for more highly doped samples. Possible reasons for this disagreement are discussed.

摘要： Partial-wave phase shifts for the scattering of electrons and holes of arbitrary degeneracy by a screened Coulomb potential have been calculated assuming isotropic, parabolic energy bands. For free particles in the effective-mass approximation, all such interactions can be characterized by two parameters. At each point in this two-dimensional space, two final results have been obtained from which the transport integrals can be evaluated. One is a sum of the phase shifts which must be employed in satisfying the Friedel sum rule, while the other corresponds to the total momentum-transfer cross section due to all partial waves. For a parametric space which includes nearly all experimental conditions of interest, these results are presented in approximate analytic form. Over a broad range of electron and hole concentrations and temperatures in Ge, Si, and GaAs, comparison is made between ionized-impurity mobilities calculated from the phase shifts and those obtained in the Born approximation.

关键词： 地表移动   等值线图   行打印   计算结果   等值图   地质图   计算机   地表移动参数  

摘要： 应用电子计算机计算地表移动和变形,为选择开采方案,分析地表移动规律提供了方便条件。尤其是利用电子计算机绘制等值线图,有效地解决了手工劳动难以实现的问题;用计算机直接打印宽行结果,不但省略了计算结果的整理时间,而且用计算机输出计算表格清楚,美观便于使用。本程序是根据概率积分法任意点任意方向的计算公式,采用ALGOL标准法语言编制的(程序内容省略)。计算速度快,精确可靠,代替了繁锁的手工计算。

关键词： 采动程度   下沉曲线   拐点   地质采矿条件   扭转点   地表移动   负指数函数法   充分采动   移动盆地   物理意义  

摘要： 前言为了沿主断面计算地表移动,提出了各种不同的剖面函数,负指数函数法就是其中之一。这种方法所用的公式是:式中 W—剖面上一点的下沉值; W_o—剖面上的最大下沉值,这里不区分是充分采动还是非充分采动; x—剖面上一点的横坐标,以最大下沉点的横坐标为零; L—半个移动盆地之长,即由最大下沉点到盆地边界点的距离; a、b—决定于具体地质采矿条件的参数。其坐标系统如图1所示。

关键词： Differential Geometry   Planetary Orbit   Shift Calculation   Perihelion Precession   Perihelion Shift  

摘要： In this paper an attempt is made to resolve a confusion which exists in the literature over whether the perihelion precession of planetary orbits is a linear or non-linear effect. The problem is both one of physics and semantics. © 1974 Plenum Publishing Company Limited.

摘要： A method for computing phase shifts recently proposed by Bolsterli based upon a new non-singular scattering integral equation is shown to be a special case of the so-called generalized Sasakawa technique. This observation leads to a simplification of the practical exploitation of the method as well as an extension to the calculation of half-off-shell amplitudes.

摘要： The Knight shift Ks and nuclear spin-relaxation time T1 have been calculated in liquid Mg using the pseudopotential theory. The results of this calculation show that both Ks and T1T are independent of temperature T within the error in our calculation. The calculated value of Ks at the melting temperature (651 ° C) is (0.10 ± 0.005)% which compares well with the recent experimental measurement (0.112 ± 0.004)% made between - 196 and 230 ° C. From this evidence, it can be concluded that there is no significant change of Ks upon melting, contrary to what has been observed in Cd. The theoretical value of the Korringa ratio, (Ks2T1T)theor(Ks2T1T)ideal, departs from its ideal value of unity by about 17%. This departure is attributed to the different role of exchange enhancement on the uniform and nonuniform spin paramagnetic susceptibilities.

摘要： Calculations of chemical shifts for carbon, nitrogen and oxygen are presented. The method is similar to that proposed by Pople and Santry for N.M.R. coupling constants. Wave functions were calculated from an extended Hückel model without overlap and a restricted set of excited states used to evaluate the paramagnetic term. Using a single parameter for each atom reasonable results were obtained.