Removing multiplicities in by double newtonization

The graphical analysis of the zero level curves of the imaginary and real parts of a complex-valued analytic function f is used, both to localize the zeros of the function and to count their multiplicities. The comparison of the referred level curves with the zero level curves of F=f/f^′ (for which a multiple zero of f becomes simple) is made in order to predict good initial guesses for the iterative process defined by the iteration function N_f, which we called the double newtonization of f. This approach enables us to obtain high precision approximations for the zeros of f, regardless of their multiplicities. Several examples of analytic functions are presented to illustrate the results obtained. In these examples the occurrence of extraneous zeros is observed, and their location is in agreement with a classical theorem of Gauss–Lucas for polynomials.     

激光金等离子体中Au52+静态能级寿命的相对论多组态计算

根据扩展的相对论多组态Dirac-Fock理论,采用"多功能相对论原子结构程序(GRASP2)",计算类钴Au52+的能级寿命、能级宽度和光谱跃迁波长,计算所得波长值与实验结果符合较好.能级寿命与能级宽度的大小关系符合海森堡的能量与时间测不准原理.     

Landau-Ginzburg method applied to finite fermion systems: Pairing in nuclei

Given the spectrum of a Hamiltonian, a methodology is developed which employs the Landau-Ginsburg theory for characterizing phase transitions in infinite systems to identify phase transition remnants in finite fermion systems. As a first application of our appproach we discuss pairing in finite nuclei.     

Photofragment space distribution in the photodissociation of NaI in the spectral range 315–370 nm: the role of molecular axis rotation

The first determination of translational anisotropy parameters β in the photodissociation of NaI molecules in the spectral range 315–370 nm is reported. The anisotropy parameters were determined by the analysis of Doppler resolved absorption profiles of Na(²S_1/2) atoms produced in the photodissociation of NaI by linearly polarized light. The profiles were recorded for two orientations of the photolysis light: parallel and perpendicular to the direction of the probe beam. The value of the parameter β was obtained from a simultaneous fit of the profiles. The role of the rotation of the parent molecules on the branching ratio between parallel and perpendicular transitions in NaI during dissociation is discussed.     

Numerical simulation of the 3-dimensional combustion of aluminized heterogeneous propellants

We report the first 3-dimensional simulations of aluminized propellant combustion, accounting for heat conduction in the solid, combustion in the gas-phase, and coupling of these via the irregularly moving propellant surface, one that can not be defined by a single-valued height function. The simulations are used to examine the dynamics of aluminum particles in the near-neighborhood of the surface after detachment, and to provide an estimate of the time to ignition of the particles, and their speed and height above the surface at ignition. In addition, we examine the temperature history of the particles during their rise to the surface, determine whether they melt or not, and in this way test Cohen’s well-known melting criterion. And, we discuss a simple model which provides insights into how aluminum particles floating on a binder melt layer would migrate because of surface tension effects, and calculate an average migration distance that is consistent with previous agglomeration studies.     

Income distribution dependence of poverty measure: A theoretical analysis

Using a modified deprivation (or poverty) function, in this paper, we theoretically study the changes in poverty with respect to the ‘global’ mean and variance of the income distribution using Indian survey data. We show that when the income obeys a log-normal distribution, a rising mean income generally indicates a reduction in poverty while an increase in the variance of the income distribution increases poverty. This altruistic view for a developing economy, however, is not tenable anymore once the poverty index is found to follow a pareto distribution. Here although a rising mean income indicates a reduction in poverty, due to the presence of an inflexion point in the poverty function, there is a critical value of the variance below which poverty decreases with increasing variance while beyond this value, poverty undergoes a steep increase followed by a decrease with respect to higher variance. Identifying this inflexion point as the poverty line, we show that the pareto poverty function satisfies all three standard axioms of a poverty index [N.C. Kakwani, Econometrica 43 (1980) 437; A.K. Sen, Econometrica 44 (1976) 219] whereas the log-normal distribution falls short of this requisite. Following these results, we make quantitative predictions to correlate a developing with a developed economy.     

Local Times and Related Properties of Multidimensional Iterated Brownian Motion

Let {W(t), tR} and {B(t), t0} be two independent Brownian motions in R with W(0) = B(0) = 0 and let

基于PEMS测量的机动车尾气预测研究

为了实现对机动车尾气排放的控制,解决现有预测模型未能通过燃油消耗来研究污染物排放以及未能建立起油耗及其车外可观测影响因素之间的关系问题,对油耗数据及其理论模型进行了研究,提出了微观综合预测模型,它是根据便携式尾气测量系统(PEMS)实际工况下测量的机动车油耗与各污染物排放数据,并结合油耗的理论模型建立起的综合预测模型;最后,通过实验对综合预测模型进行了实例分析与验证;实验结果表明,综合预测模型首次对污染物CO和NO的预测模拟值和实测值之间的平均误差分别为14.3%和12.8%,实现了较好的预测效果,为进一步研究燃油消耗和排放的关系奠定了很好的基础。     

一种软件工程管理模型研究

软件作为一种逻辑实体,具有难以度量、易出错、必须维护和成本昂贵等显著的特点。在规定的时间和预算内开发出符合质量要求的软件是一件非常困难的事情。经过国内外40多年来的研究与分析,发现产生这一问题的关键原因在于对软件过程的管理不尽如人意。为了提高软件工程管理的水平,国内外工程界尝试过很多的方法和手段,比如：制定并实施软件工程标准和规范、使用工具提高软件生产率和质量、通过软件评测促进工程化水平等。虽然GJB 5000A标准从理论上和体系上对软件工程管理提供了一定的参考,但在实际工程中仍缺乏一套完整、易于实施、体现技术管理特点的软件工程管理模型作为一个项目管理的指导。因此,为了应对上述问题,解决工程实际中的困难,文中面向软件工程项目管理的需要,提出一种的分层次、全周期、多角度的软件工程管理模型,并通过一个项目实例进行分析和验证。最后,文中将对软件工程管理研究的发展趋势进行展望。