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1.
Jyoti Shah 《Nuclear Physics A》1968,120(3):530-534
A general method is described for computing central as well as tensor force matrix elements for shell-model states. The method consists of expanding the two-body potential into free multipole fields. The advantages of the method are that

(i) arbitrary forms of the average and two-body potential can be chosen; (ii) even in the case of a finite-range force, double integrals are eliminated, and the radial integrals are independent of the shape and parameters of the two-body force; and (iii) the central and the tensor forces are treated on the same footing.

FORTRAN codes employing this method are available for the computation of the two-body force matrix elements for an arbitrary nucleus.  相似文献   


2.
趋近平均法测量普朗克常量   总被引:4,自引:2,他引:4  
武颖丽  李平舟 《物理实验》2007,27(4):42-43,47
为解决光电效应实验中的测量误差较大问题,提出了“趋近平均法”对普朗克常量进行测量,可使测量误差由使用拐点法的34%降至13.5%.  相似文献   

3.
对电子束能量沉积剖面的变化规律进行了解释,给出了由能量损失函数和能量沉积效率函数之积表示的定性的能量沉积函数表达式。在此基础上,给出了一种关于能量沉积剖面的电子束等效入射角计算方法,分析了方法所带来的影响和适用的范围,采用蒙特卡罗方法对等效结果进行了验证。证明该方法优于入射角的算术平均,尤其在靶材浅层与混合束符合较好。  相似文献   

4.
对电子束能量沉积剖面的变化规律进行了解释,给出了由能量损失函数和能量沉积效率函数之积表示的定性的能量沉积函数表达式。在此基础上,给出了一种关于能量沉积剖面的电子束等效入射角计算方法,分析了方法所带来的影响和适用的范围,采用蒙特卡罗方法对等效结果进行了验证。证明该方法优于入射角的算术平均,尤其在靶材浅层与混合束符合较好。  相似文献   

5.
半解析求解平均原子模型方法充分利用了已知精确波函数的解析性质,通过对平均原子模型中势函数的数值拟合,就得到仅含一个数值因子的半解析波函数以及相应的能量本征值.本文列出了等离子体中相对论性平均原子模型的诸方程,特别注意方程求解技术和程序设计中的一些细节.与完全数值解以及其他类似模型得到的数值解进行的比较表明,在较高温度条件下半解析结果的精度是相当高的,求解的效率也很高.此外还对物理模型中某些缺陷进行了分析.  相似文献   

6.
An optical method for remotely determining the average crosswind under all conditions of atmospheric turbulence is proposed and analyzed. The method depends upon the phase structure function, which does not saturate with increasing range or strength of turbulence. The method also has the advantage that the path-weighting functions are almost constant over the entire path - in contrast to the highly selective path-weighting functions appropriate to remote wind-sensing using amplitude scintillations.  相似文献   

7.
We investigate the problem of detecting clusters exhibiting higher-than-average internal connectivity in networks of interacting systems. We show how the average association objective formulated in the context of spectral graph clustering leads naturally to a clustering strategy where each system is assigned to at most one cluster. A residual set is formed of the systems that are not members of any cluster. Maximization of the average association objective leads to a discrete optimization problem, which is difficult to solve, but a relaxed version can be solved using an eigendecomposition of the connectivity matrix. A simple approach to extracting clusters from a relaxed solution is described and developed by applying a variance maximizing solution to the relaxed solution, which leads to a method with increased accuracy and sensitivity. Numerical studies of theoretical connectivity models and of synchronization clusters in a lattice of coupled Lorenz oscillators are conducted to show the efficiency of the proposed approach. The method is applied to an experimentally obtained human resting state functional magnetic resonance imaging dataset and the results are discussed.  相似文献   

8.
针对H.264码率控制模型的“蛋鸡悖论”,提出一种用平均预测残差来表示当前宏块编码复杂度的算法。首先根据各个宏块不同的编码复杂度进行准确的比特分配,然后根据改进的二次R-D预测模型来计算宏块的量化参数,并进行率失真优化,最后进行码率控制模型系数的更新。将算法在JM8.6平台上进行实验,结果显示,在相同码率下,本文算法的平均控制精度比JVT-H017提高0165 kb/s,平均PSNR比JVT-H017提高013 dB,表明本算法能够更准确控制码率并获得更高质量的主观视觉。  相似文献   

9.
Using a previously proposed model as a basis, an investigation is made of the functional dependence of the average multiplicity on impact parameter and momentum transfer. The results are compared with those obtained using a probabilistic approach. The advantage of this method is that the information desired is derived from elastic scattering data.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 18–22, March, 1979.  相似文献   

10.
An efficient method for calculating the Lagrange multipliers and the analytical gradients of one state included in a state average MCSCF wave function is presented. It is demonstrated that the state average energy of an ‘equal-weight’ scheme is invariant to rotations within the state average subspace and that the corresponding rotations should be eliminated from the Lagrangian equations. Finally, a diagnostic is presented, which gauges the energy difference between a state defined by a state average calculation and the corresponding fully variational multi-configurational SCF state.  相似文献   

11.
In this study, analytical expressions are obtained for two different types of two-center EFG integrals and the integrals are calculated using these expressions. Analytical expressions for the integrals are given in terms of auxiliary J and K functions defined by Özmen et al. [Int. J. Quantum Chem. 91, 13 (2003)] for the evaluation of two-center Coulomb integrals using elliptical coordinates. Results are compared and found to be in good agreement for small quantum numbers with the existing results from the literature. Numerical stability of the proposed method is very good and therefore we also present results for higher quantum numbers, however there is no previous results found in the literature to compare.  相似文献   

12.
The mechanisms for the increase in the global average sea level in the present epoch are studied. The phenomenon of contrasting secular Southern and Northern Hemisphere average sea-level changes is explained; this phenomenon was predicted earlier by the author on the basis of the observed secular northward trend of the Earth’s center of mass at a rate of 5–6 mm/yr. Studies of sea-level changes using altimetry method are criticized.  相似文献   

13.
在假设导轨为半无限长固体导体及电枢表面磨损主要是熔化磨损条件下,基于固体接触面导热原理,推导出电枢和导轨温度分布方程,提出了电枢平均磨损率计算方法。利用此方法分析了驱动电流、电枢和导轨材料匹配和接触面积参数对电枢平均磨损率影响。将平均磨损率计算结果与Stefani和Parker的实验结果进行对比,二者吻合较好,从而为建立电磁轨道炮磨损率与转捩之间的关系提供理论支持。  相似文献   

14.
用动力学方法研究原子分子碰撞过程中的统计平均问题   总被引:1,自引:0,他引:1  
动力学李代数方法在研究原子分子碰撞问题中是一种很重要的方法.在计算过程中我们用密度算子导出了物理量的统计平均值.同时我们用时间演化算子计算了振转能量的跃迁几率.作为例子我们用此方法计算了H2和He的碰撞问题.  相似文献   

15.
Using the Unsöld average energy method a double perturbation theory expression for the interaction energy through second order is obtained which includes intra-atomic correction terms arising from the use of trial wavefunctions to represent the non-interacting molecules. These formal expressions are applied to the ground state He-He interaction and results for the interaction energy are obtained that compare favourably with recent semiempirical and ab initio calculations. The Unsöld calculations are used to investigate approximations that have been introduced into the average energy calculation by other workers, and as a model for discussing the relative importance of second-order charge overlap and exchange effects and the convergence of the multipole treatment of the interaction energy for this typical non-bonded interaction. The results illustrate the importance of knowing as many terms as possible in the R -1 expansion of the energy. Finally a portion of this work required the recalculation of the He-He repulsive energy obtained by using the Eckart wavefunction to represent the helium atom. The resultant energy is approximately 25 per cent lower than that previously obtained using this wavefunction for most values of R.  相似文献   

16.
Bound on average multiplicity is derived using polynomial boundedness of multiparticle generating function. Consequences of distribution of zeros of the generating function and its connection with improvement of the bound is studied.  相似文献   

17.
Engineering systems such as aircraft, ships and automotive are considered built-up structures. Dynamically they are taught of as being fabricated from many components that are classified as ‘deterministic subsystems’ (DS) and ‘non-deterministic subsystems’ (Non-DS). Structures' response of the DS is deterministic in nature and analysed using deterministic modelling methods such as finite element (FE) method. The response of Non-DS is statistical in nature and estimated using statistical modelling technique such as statistical energy analysis (SEA). SEA method uses power balance equation, in which any external input to the subsystem must be represented in terms of power. Often, input force is taken as point force and ensemble average power delivered by point force is already well-established. However, the external input can also be applied in the form of moments exerted by a piezoelectric (PZT) patch actuator. In order to be able to apply SEA method for input moments, a mathematical representation for moment generated by PZT patch in the form of average power is needed, which is attempted in this paper. A simply-supported plate with attached PZT patch is taken as a benchmark model. Analytical solution to estimate average power is derived using mobility approach. Ensemble average of power given by the PZT patch actuator to the benchmark model when subjected to structural uncertainties is also simulated using Lagrangian method and FEA software. The analytical estimation is compared with the Lagrangian model and FE method for validation. The effects of size and location of the PZT actuators on the power delivered to the plate are later investigated.  相似文献   

18.
高雪清  姜德生 《应用光学》2006,27(6):581-584
光纤Bragg光栅(FBG)传感器是一种波长调制型传感器,波长解调技术是FBG传感系统的关键,通常是对FBG反射谱进行波形采样,得到反射谱的峰值信号,以此作为FBG中心波长的特征值。这种方法需要实时采集大量数据,所以影响解调速度。通过对FBG反射谱的分析,得出FBG反射谱具有很好的对称性。在此基础上提出了采用反射波双边缘均值的方法测算中心波长。实验证明,采用这种方法进行波长解调,可以使FBG信号处理简单、动、静态波长时测算精度高,可以极大地提高解调系统处理FBG传感信号的速度。  相似文献   

19.
陈桂波  毕娟  汪剑波  陈新邑  孙贯成  卢俊 《物理学报》2011,60(9):94102-094102
本文利用提取直射波并结合自适应数字滤波等技术提出一种计算水平层状介质中电磁场并矢Green函数的快速算法. 首先将谱域Green函数中表征均匀介质作用的直射波提取出来并对其积分进行解析计算,这种处理降低了谱域Green函数的奇异性,可在很大程度上缩短其积分收敛区间. 然后在将谱域Green函数剩余部分对应积分转化为三个快速下降积分的基础上,引入一种自适应数字滤波算法对其进行快速求解. 最后通过具体算例验证了本文所述算法的有效性. 关键词: 并矢Green函数 快速算法 水平层状介质  相似文献   

20.
秦晓东  黄勇  刘维  刘纪元 《应用声学》2011,30(6):443-447
本论文以相位差平均波动函数法为基础,提出了多视波动配准方法。该方法首先对配准图像对进行多视平均处理,再对多视处理后的干涉图求取相位差平均波动函数值。该配准方法抑制了配准过程中的多峰现象,在精度和运算量上都有一定的改进,且没有继承多视处理降低二维分辨率的缺点。实际湖试数据验证了该方法的效果。后续处理得到的干涉图条纹清晰,并与实际地形吻合。  相似文献   

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